Effects of bacterial direct-fed microbials on ruminal characteristics, methane emission, and milk fatty acid composition in cows fed high- or low-starch diets.

PubMed

Philippeau, C; Lettat, A; Martin, C; Silberberg, M; Morgavi, D P; Ferlay, A; Berger, C; Nozière, P

2017-04-01

This study investigated the effects of bacterial direct-fed microbials (DFM) on ruminal fermentation and microbial characteristics, methane (CH 4 ) emission, diet digestibility, and milk fatty acid (FA) composition in dairy cows fed diets formulated to induce different ruminal volatile fatty acid (VFA) profiles. Eight ruminally cannulated dairy cows were divided into 2 groups based on parity, days in milk, milk production, and body weight. Cows in each group were fed either a high-starch (38%, HS) or a low-starch (2%, LS) diet in a 55:45 forage-to-concentrate ratio on a dry matter (DM) basis. For each diet, cows were randomly assigned to 1 of 4 treatments in a Latin square design of (1) control (CON); (2) Propionibacterium P63 (P63); (3) P63 plus Lactobacillus plantarum 115 (P63+Lp); (4) P63 plus Lactobacillus rhamnosus 32 (P63+Lr). Strains of DFM were administered at 10 10 cfu/d. Methane emission (using the sulfur hexafluoride tracer technique), total-tract digestibility, dry matter intake, and milk production and composition were quantified in wk 3. Ruminal fermentation and microbial characteristics were measured in wk 4. Data were analyzed using the mixed procedure of SAS (SAS Institute Inc., Cary, NC). The 2 diets induced different ruminal VFA profiles, with a greater proportion of propionate at the expense of acetate and butyrate for the HS diet. Greater concentrations of total bacteria and selected bacterial species of methanogenic Archaea were reported for the HS diet, whereas the protozoa concentration in HS decreased. For both diets, bacterial DFM supplementation raised ruminal pH (+0.18 pH units, on average) compared with CON. Irrespective of diet, P63+Lp and P63+Lr increased ruminal cellulase activity (3.8-fold, on average) compared with CON, but this effect was not associated with variations in ruminal microbial numbers. Irrespective of diet, no effect of bacterial DFM on ruminal VFA was observed. For the LS diet, supplementing cows with P63+Lr tended to decrease CH 4 emission (26.5%, on average, when expressed per kilogram of milk or 4% fat-corrected milk). Only P63 supplementation to cows fed the HS diet affected the concentration of some milk FA, such as cis isomers of 18:1 and intermediates of ruminal biohydrogenation of polyunsaturated FA. Overall, bacterial DFM could be useful to stabilize ruminal pH. Their effects on CH 4 production mitigation and milk FA profile depended on DFM strain and diet and should be confirmed under a greater variation of dietary conditions. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Invitro Study on the Fluid From Banana Stem Bioprocess as Direct Fed Microbial

NASA Astrophysics Data System (ADS)

Mutaqin, B. K.; Tanuwiria, U. H.; Hernawan, E.

2018-02-01

The purpose of this research was to study the liquid produced by the bioprocess of banana stem as a Direct Fed Microbial (DFM) in order to enhance local sheep productivity invitro. Studying was the use of DFM in two invitro feeds. The object observed in this research was fermentability and digestibility value. The method was experimental with the experimental design, i.e. factorial experimental design with two factors. The first factor was DFM, the levels of which were 0, 0,2, 0,4 and 0,6%, while the second factor was two feed types (complete feed and Pennisetum purpureum only) with the treatment of threefold repetition. This research showed that fermentability and digestibility value were influenced by the DFM in the invitro complete feed. The research result analyzed using MANOVA with further testing using Duncan Test. The conclusion of the research result were shows the interaction DFM in the complete feed improve fermentability and digestibility values and DFM 0,6% shows the highest value.

Synthetic Klebsiella pneumoniae-Shewanella oneidensis Consortium Enables Glycerol-Fed High-Performance Microbial Fuel Cells.

PubMed

Li, Feng; Yin, Changji; Sun, Liming; Li, Yuanxiu; Guo, Xuewu; Song, Hao

2018-05-01

Microbial fuel cell (MFC) is an eco-friendly bio-electrochemical sys-tem that uses microorganism as biocatalyst to convert biomass into electricity. Glycerol, as a waste in the biodiesel refinery processes, is an appealing substrate for MFC. Nevertheless, glycerol cannot be utilized as carbon source by well-known exoelectrogens such as Shewanella oneidensis. Herein, to generate electricity by rapidly harnessing glycerol, the authors rationally constructed a Klebsiella pneumoniae-Shewanella oneidensis microbial consortium to efficiently harvest electricity from glyc-erol, in which K. pneumoniae converted glycerol into lactate, fed to S. oneidensis as carbon source and electron donor. To improve electricity output, the authors systematically engineered the consortium in terms of carbon flux distribution and efficiency of extracellular electron transfer (EET). To direct more carbon flux to lactate biosynthesis in K. pneumoniae, the authors eliminated the ethanol pathway by knocking out the alcohol dehydrogenase gene (adhE), and enhanced lactate biosynthesis by heterologously expressing a lactate dehydrogen-ase gene (ldhD) from Lactobacillus bulgaricus and a lactate transporter gene (lldP) from Escherichia coli. To facilitate EET between S. oneidensis and anode surfaces, a biosynthetic flavins pathway from Bacillus subtilis is introduced into S. oneidensis. The author further optimized the glycerol concentration, thus S. oneidensis could be continuously fed with lactate synthesized from K. pneumoniae at a constant rate. Our glycerol-fed MFC generated a maximum power density of 19.9 mW/m 2 , significantly higher than that of the wild-type consor-tium. This work suggested that engineering microbial consortia is an effi-cient strategy to expand the spectrum of usable carbon sources and promote electricity power production in MFCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Direct-fed Microbial and Pine Cone Extract on Carcass Traits and Meat Quality of Hanwoo (Korean Native Cattle)

PubMed Central

Muhlisin; Song, Chang Soo; Rhee, Yong Joon; Song, Young Han; Lee, Sung Ki

2016-01-01

The carcass traits and meat quality of Hanwoo (Korean native cattle) whose diets were supplemented with direct-fed microbial (DFM) and pine cone extract (PCE) were evaluated. Twenty head of Hanwoo steers were divided equally into four groups and for a period of 6 months were given different diets: One group was fed a basal diet as control (CON), the other three groups were fed a basal diet supplemented with DFM-1%, DFM+PCE-1% and DFM+PEC-3%, respectively. DFM+PCE3% diet resulted the lowest carcass quality grade. The loins of DFM-1% contained higher moisture and lower fat than did the loins from the CON group. The crude protein content of DFM+PCE-3% group was significantly higher than that of the other groups. The water holding capacity and Warner-Bratzler shear force of the DFM+PCE-1% and 3% groups were lower than those of the CON and DFM-1% groups. The DFM-1% and 3% groups contained lower saturated fatty acid, higher unsaturated fatty acid, mono-unsaturated fatty acid, and poly-unsaturated fatty acid than did CON and DFM+PCE 1% group. Moreover, the n6:n3 ratios of DFM-1% and DFM+PCE-1% and 3% groups were slightly lower than that of the CON group. Thus we concluded that DFM and PCE supplementation resulted healthier Hanwoo beef with lower fat content and n6:n3 ratio. PMID:26954123

Performance of broiler chickens fed diets supplemented with a direct-fed microbial.

PubMed

Angel, R; Dalloul, R A; Doerr, J

2005-08-01

From hatch to 18 d of age broilers were fed starter diets with (0.9 kg/ton) or without direct fed microbial (DFM). At 18 d, birds were weighed and, within DFM treatment (trt), randomly assigned to battery pens. In Exp 1, a 2 x 2 factorial arrangement of nutrient density [control (C, 19.3% protein (CP), 0.84%, Ca 0.37% nonphytin P (nPP); and 17.1% CP, 0.8% Ca, and 0.3% nPP in the grower (Gr) and finisher (Fn) diets, respectively) and moderate (M) (17% CP, 0.69% Ca, 0.30% nPP; 15% CP, 0.66% Ca, 0.25% nPP in the Gr and Fn diets, respectively)] and DFM concentration [0 or 0.9 kg/ton (++)] was used. Exp 2 was a 2 (DSM at 0 and 0.45 kg/ton) x 3 (nutrient densities) factorial. Exp 2 included a low (L) nutrient density that differed from diet M only in Ca and nPP concentrations and an added trt, diet M with 0.45 kg/ ton DFM as in Exp 1. At the end of the Gr and Fn weight, feed efficiency, apparent nutrient retention were determined, and 4 birds per pen were sampled for tibia ash. In Exp 2, gains in the Gr phase were 1,122.0, 983.7, 1,121.5, 930.7, and 1,151.5 g in birds fed the C, M, M+, L, and L+ diets, respectively. Addition of DFM to the M diet overcame the negative effect of nutrient concentration on performance but not when the L diet was fed. Nutrient level and DFM affected apparent protein, Ca, and P retention at 32 or 42 d of age with retention increasing as nutrient level decreased and with DFM added to the diet. Ca and P retention at 28 d (Exp 1) was higher in birds fed M++ (45.8 and 46%, respectively) than in those fed the C diet (38.7 and 40.0%, respectively). Feeding the M and L diets resulted in lower tibia ash than that of birds fed the C diet, but the addition of DFM to low nutrient diets overcame this negative effect.

A small variation in diet influences the Lactobacillus strain composition in the crop of broiler chickens.

PubMed

Hammons, Susan; Oh, Phaik Lyn; Martínez, Inés; Clark, Kenzi; Schlegel, Vicki L; Sitorius, Emily; Scheideler, Sheila E; Walter, Jens

2010-08-01

Feed composition has the potential to influence the activities of bacteria that colonize the digestive tract of broiler chickens with important consequences for animal health, well being, and food safety. In this study, the gut microbiota of two groups of broiler chickens raised in immediate vicinity but fed either a standard corn/soybean meal ration (corn-soy, CS) or a ration high in wheat middlings (high wheat, HW) was characterized. The findings revealed that this small variation in feed composition did not influence the distribution of microbial species present in the microbial community throughout the digestive tract. However, diet variation markedly influenced the Lactobacillus strain composition in the crop. Most striking, the dominant type in birds on the CS diet (Lactobacillus agilis type R5), which comprised 25% of the isolates, was not detected in birds fed the HW diet. The latter birds harbored a different strain of L. agilis (type R1) in a significantly higher ratio than birds on the CS diet. Several other strains were also specific to the particular diet. In conclusion, this study showed that a small variation in the composition of chicken feed that does not result in detectable differences in species composition can still have an impact on which microbial strains become dominant in the digestive tract. This finding has relevance in the application of probiotics and other direct-fed microbials in poultry husbandry. Copyright 2010 Elsevier GmbH. All rights reserved.

Bacillus spp. as direct-fed microbial antibiotic alternatives to enhance poultry growth, immunity and intestinal health

USDA-ARS?s Scientific Manuscript database

The increasing occurrence of antibiotic-resistant bacteria combined with regulatory pressure and consumer demands for foods produced without antibiotics has caused the agricultural industry to restrict its practice of using antibiotic growth promoters (AGPs) in feed animals. The poultry industry is ...

Microbial fuel cell coupled to biohydrogen reactor: a feasible technology to increase energy yield from cheese whey.

PubMed

Wenzel, J; Fuentes, L; Cabezas, A; Etchebehere, C

2017-06-01

An important pollutant produced during the cheese making process is cheese whey which is a liquid by-product with high content of organic matter, composed mainly by lactose and proteins. Hydrogen can be produced from cheese whey by dark fermentation but, organic matter is not completely removed producing an effluent rich in volatile fatty acids. Here we demonstrate that this effluent can be further used to produce energy in microbial fuel cells. Moreover, current production was not feasible when using raw cheese whey directly to feed the microbial fuel cell. A maximal power density of 439 mW/m 2 was obtained from the reactor effluent which was 1000 times more than when using raw cheese whey as substrate. 16S rRNA gene amplicon sequencing showed that potential electroactive populations (Geobacter, Pseudomonas and Thauera) were enriched on anodes of MFCs fed with reactor effluent while fermentative populations (Clostridium and Lactobacillus) were predominant on the MFC anode fed directly with raw cheese whey. This result was further demonstrated using culture techniques. A total of 45 strains were isolated belonging to 10 different genera including known electrogenic populations like Geobacter (in MFC with reactor effluent) and known fermentative populations like Lactobacillus (in MFC with cheese whey). Our results show that microbial fuel cells are an attractive technology to gain extra energy from cheese whey as a second stage process during raw cheese whey treatment by dark fermentation process.

Effect of Bacillus amyloliquefaciens-based Direct-fed Microbial on Performance, Nutrient Utilization, Intestinal Morphology and Cecal Microflora in Broiler Chickens

PubMed Central

Lei, Xinjian; Piao, Xiangshu; Ru, Yingjun; Zhang, Hongyu; Péron, Alexandre; Zhang, Huifang

2015-01-01

The present study was conducted to evaluate the effect of the dietary supplementation of Bacillus amyloliquefaciens-based direct-fed microbial (DFM) on growth performance, nutrient utilization, intestinal morphology and cecal microflora in broiler chickens. A total of two hundred and eighty eight 1-d-old Arbor Acres male broilers were randomly allocated to one of four experimental treatments in a completely randomized design. Each treatment was fed to eight replicate cages, with nine birds per cage. Dietary treatments were composed of an antibiotic-free basal diet (control), and the basal diet supplemented with either 15 mg/kg of virginiamycin as antibiotic growth promoter (AGP), 30 mg/kg of Bacillus amyloliquefaciens-based DFM (DFM 30) or 60 mg/kg of Bacillus amyloliquefaciens-based DFM (DFM 60). Experimental diets were fed in two phases: starter (d 1 to 21) and finisher (d 22 to 42). Growth performance, nutrient utilization, morphological parameters of the small intestine and cecal microbial populations were measured at the end of the starter (d 21) and finisher (d 42) phases. During the starter phase, DFM and virginiamycin supplementation improved the feed conversion ratio (FCR; p<0.01) compared with the control group. For the finisher phase and the overall experiment (d 1 to 42) broilers fed diets with the DFM had better body weight gain (BWG) and FCR than that of control (p<0.05). Supplementation of virginiamycin and DFM significantly increased the total tract apparent digestibility of crude protein (CP), dry matter (DM) and gross energy during both starter and finisher phases (p<0.05) compared with the control group. On d 21, villus height, crypt depth and villus height to crypt depth ratio of duodenum, jejunum, and ileum were significantly increased for the birds fed with the DFM diets as compared with the control group (p<0.05). The DFM 30, DFM 60, and AGP groups decreased the Escherichia coli population in cecum at d 21 and d 42 compared with control group (p<0.01). In addition, the population of Lactobacillus was increased in DFM 30 and DFM 60 groups as compared with control and AGP groups (p<0.01). It can be concluded that Bacillus amyloliquefaciens-based DFM could be an alternative to the use of AGPs in broilers diets based on plant protein. PMID:25557820

Effect of direct-fed microbial supplementation on the presence of Salmonella enterica in bovine peripheral lymph nodes

USDA-ARS?s Scientific Manuscript database

Introduction: Bovine peripheral lymph nodes (LN) contained within adipose trim, have been identified as a potential source of human exposure to Salmonella enterica, when incorporated into ground beef. How Salmonella gain entry to peripheral LN is a question yet to be answered, however recent survey...

The use of direct-fed microbials for mitigation of ruminant methane emissions: a review.

PubMed

Jeyanathan, J; Martin, C; Morgavi, D P

2014-02-01

Concerns about the environmental effect and the economic burden of methane (CH4) emissions from ruminants are driving the search for ways to mitigate rumen methanogenesis. The use of direct-fed microbials (DFM) is one possible option to decrease CH4 emission from ruminants. Direct-fed microbials are already used in ruminants mainly to increase productivity and to improve health, and are readily accepted by producers and consumers alike. However, studies on the use of DFM as rumen CH4 mitigants are scarce. A few studies using Saccharomyces cerevisiae have shown a CH4-decreasing effect but, to date, there has not been a systematic exploration of DFM as modulators of rumen methanogenesis. In this review, we explored biochemical pathways competing with methanogenesis that, potentially, could be modulated by the use of DFM. Pathways involving the redirection of H2 away from methanogenesis and pathways producing less H2 during feed fermentation are the preferred options. Propionate formation is an example of the latter option that in addition to decrease CH4 formation increases the retention of energy from the diet. Homoacetogenesis is a pathway using H2 to produce acetate, however up to now no acetogen has been shown to efficiently compete with methanogens in the rumen. Nitrate and sulphate reduction are pathways competing with methanogenesis, but the availability of these substances in the rumen is limited. Although there were studies using nitrate and sulphate as chemical additives, use of DFM for improving these processes and decrease the accumulation of toxic metabolites needs to be explored more. There are some other pathways such as methanotrophy and capnophily or modes of action such as inhibition of methanogens that theoretically could be provided by DFM and affect methanogenesis. We conclude that DFM is a promising alternative for rumen methane mitigation that should be further explored for their practical usage.

The role of breast-feeding in infant immune system: a systems perspective on the intestinal microbiome.

PubMed

Praveen, Paurush; Jordan, Ferenc; Priami, Corrado; Morine, Melissa J

2015-09-24

The human intestinal microbiota changes from being sparsely populated and variable to possessing a mature, adult-like stable microbiome during the first 2 years of life. This assembly process of the microbiota can lead to either negative or positive effects on health, depending on the colonization sequence and diet. An integrative study on the diet, the microbiota, and genomic activity at the transcriptomic level may give an insight into the role of diet in shaping the human/microbiome relationship. This study aims at better understanding the effects of microbial community and feeding mode (breast-fed and formula-fed) on the immune system, by comparing intestinal metagenomic and transcriptomic data from breast-fed and formula-fed babies. We re-analyzed a published metagenomics and host gene expression dataset from a systems biology perspective. Our results show that breast-fed samples co-express genes associated with immunological, metabolic, and biosynthetic activities. The diversity of the microbiota is higher in formula-fed than breast-fed infants, potentially reflecting the weaker dependence of infants on maternal microbiome. We mapped the microbial composition and the expression patterns for host systems and studied their relationship from a systems biology perspective, focusing on the differences. Our findings revealed that there is co-expression of more genes in breast-fed samples but lower microbial diversity compared to formula-fed. Applying network-based systems biology approach via enrichment of microbial species with host genes revealed the novel key relationships of the microbiota with immune and metabolic activity. This was supported statistically by data and literature.

Microbial biodiversity in glacier-fed streams

PubMed Central

Wilhelm, Linda; Singer, Gabriel A; Fasching, Christina; Battin, Tom J; Besemer, Katharina

2013-01-01

While glaciers become increasingly recognised as a habitat for diverse and active microbial communities, effects of their climate change-induced retreat on the microbial ecology of glacier-fed streams remain elusive. Understanding the effect of climate change on microorganisms in these ecosystems is crucial given that microbial biofilms control numerous stream ecosystem processes with potential implications for downstream biodiversity and biogeochemistry. Here, using a space-for-time substitution approach across 26 Alpine glaciers, we show how microbial community composition and diversity, based on 454-pyrosequencing of the 16S rRNA gene, in biofilms of glacier-fed streams may change as glaciers recede. Variations in streamwater geochemistry correlated with biofilm community composition, even at the phylum level. The most dominant phyla detected in glacial habitats were Proteobacteria, Bacteroidetes, Actinobacteria and Cyanobacteria/chloroplasts. Microorganisms from ice had the lowest α diversity and contributed marginally to biofilm and streamwater community composition. Rather, streamwater apparently collected microorganisms from various glacial and non-glacial sources forming the upstream metacommunity, thereby achieving the highest α diversity. Biofilms in the glacier-fed streams had intermediate α diversity and species sorting by local environmental conditions likely shaped their community composition. α diversity of streamwater and biofilm communities decreased with elevation, possibly reflecting less diverse sources of microorganisms upstream in the catchment. In contrast, β diversity of biofilms decreased with increasing streamwater temperature, suggesting that glacier retreat may contribute to the homogenisation of microbial communities among glacier-fed streams. PMID:23486246

Autotrophic antimonate bio-reduction using hydrogen as the electron donor.

PubMed

Lai, Chun-Yu; Wen, Li-Lian; Zhang, Yin; Luo, Shan-Shan; Wang, Qing-Ying; Luo, Yi-Hao; Chen, Ran; Yang, Xiaoe; Rittmann, Bruce E; Zhao, He-Ping

2016-01-01

Antimony (Sb), a toxic metalloid, is soluble as antimonate (Sb(V)). While bio-reduction of Sb(V) is an effective Sb-removal approach, its bio-reduction has been coupled to oxidation of only organic electron donors. In this study, we demonstrate, for the first time, the feasibility of autotrophic microbial Sb(V) reduction using hydrogen gas (H2) as the electron donor without extra organic carbon source. SEM and EDS analysis confirmed the production of the mineral precipitate Sb2O3. When H2 was utilized as the electron donor, the consortium was able to fully reduce 650 μM of Sb(V) to Sb(III) in 10 days, a rate comparable to the culture using lactate as the electron donor. The H2-fed culture directed a much larger fraction of it donor electrons to Sb(V) reduction than did the lactate-fed culture. While 98% of the electrons from H2 were used to reduce Sb(V) by the H2-fed culture, only 12% of the electrons from lactate was used to reduce Sb(V) by the lactate-fed culture. The rest of the electrons from lactate went to acetate and propionate through fermentation, to methane through methanogenesis, and to biomass synthesis. High-throughput sequencing confirmed that the microbial community for the lactate-fed culture was much more diverse than that for the H2-fed culture, which was dominated by a short rod-shaped phylotype of Rhizobium (α-Protobacteria) that may have been active in Sb(V) reduction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Supplementation of direct-fed microbial as an alternative to antibiotic on growth performance, intestinal immune status and epithelial barrier integrity in broiler chicken

USDA-ARS?s Scientific Manuscript database

The objective of this study was to investigate the effects of supplementation of broiler diets with Bacillus subtilis-based probiotics on growth performance, feed efficiency, intestinal cytokine and tight junction (TJ) protein mRNA expression. Day-old broiler chicks (n = 140) were randomly assigned...

Biological treatment of steroidal drug industrial effluent and electricity generation in the microbial fuel cells.

PubMed

Liu, Ru; Gao, Chongyang; Zhao, Yang-Guo; Wang, Aijie; Lu, Shanshan; Wang, Min; Maqbool, Farhana; Huang, Qing

2012-11-01

The single chamber microbial fuel cells (MFCs) were used to treat steroidal drug production wastewater (SPW) and generate electricity simultaneously. The results indicated that the maximum COD removal efficiency reached 82%, total nitrogen and sulfate removal rate approached 62.47% and 26.46%, respectively. The maximum power density and the Coulombic efficiency reached to 22.3Wm(-3) and 30%, respectively. The scanning electron microscope showed that the dominant microbial populations were remarkably different in morphology on the surface of SPW and acetate-fed anodes. PCR-denaturing gradient gel electrophoresis profiles revealed that the microbial community structure fed with different concentrations of SPW presented a gradual succession and unique bacterial sequences were detected on the SPW and acetate-fed anodes. This research demonstrates that MFCs fed with SPW achieved a high efficiency of power density and simultaneous nutrient removal, and the dominant microorganisms on the anode were related to the types and the concentrations of substrates. Copyright © 2012 Elsevier Ltd. All rights reserved.

Electricity generation from acetate and glucose by sedimentary bacterium attached to electrode in microbial-anode fuel cells

NASA Astrophysics Data System (ADS)

Zhang, Enren; Xu, Wei; Diao, Guowang; Shuang, Chendong

Microbial-anode fuel cells (MAFCs) with high electron recovery (>50%) from acetate and glucose have been constructed in this study. By inoculating fresh sedimentary microorganisms into anaerobic anode compartments, a stable current (∼0.42 mA for acetate-fed MAFCs; ∼0.35 mA for glucose-fed MAFCs) is generated from the oxidation of the added organic matter until its concentration decreases to a low level. SEM micrographs indicate that thick biofilms of microbial communities (coccoid cells with a diameter of ∼0.5 μm in acetate-fed MAFCs; rod-shaped cells with a length of 2.0-4.0 μm and a width of 0.5-0.7 μm in glucose-fed MAFCs) completely cover the anode electrodes. These anodophillic biofilms are thought to be responsible for the current generation, and make these microbial-anode fuel cells exhibit good performance even when the growth medium is replaced by a salt buffer without any growth factor. In comparison with those microbial fuel cells that require the addition of artificial electron transfer-mediating compounds, the findings in this study imply a potential way to develop excellent mediator-less MAFCs for electricity generation from organic matter by using substrate-induced anodophillic microbial species.

Effects of a 3 strain -based direct-fed microbial and dietary fiber concentration on growth performance and expression of genes related to absorption and metabolism of volatile fatty acids in weanling pigs.

PubMed

Jaworski, N W; Owusu-Asiedu, A; Walsh, M C; McCann, J C; Loor, J J; Stein, H H

2017-01-01

Effects of a -based direct-fed microbial (DFM) on growth performance, plasma tumor necrosis factor ɑ (TNFɑ), relative gene expression, and intestinal VFA concentrations in weanling pigs fed low- or high-fiber diets were evaluated. Two hundred pigs (initial BW: 6.31 ± 0.73 kg) were allotted to 1 of 4 dietary treatments (5 pigs per pen and 10 pens per treatment). Treatments were arranged in a 2 × 2 factorial design with 2 diet types [low-fiber (LF) or high-fiber (HF)] and 2 concentrations of DFM (0 or 60 g DFM/t of feed). The DFM contained 1.5 × 10 cfu/g and was obtained from Danisco Animal Nutrition-DuPont Industrial Biosciences, Marlborough, UK. Phase 1 diets were fed for 2 wk post-weaning and phase 2 diets were fed over the following 29 d. Low fiber diets contained corn and soybean meal as main ingredients and HF diets contained corn, soybean meal, corn distillers dried grains with solubles (7.5 and 15.0% in phase 1 and 2, respectively), and wheat middlings (10.0%). Pigs and feed were weighed at the start and at the end of each phase, and ADG, ADFI, and G:F were calculated. At the conclusion of phase 2, blood was collected from 1 pig per pen and 1 pig per pen was sacrificed. Cecum and rectum contents were analyzed for VFA, and tissue samples were collected from the ileum, cecum, rectum, and liver to determine expression of genes related to absorption and metabolism of VFA using quantitative reverse transcription-PCR. Results indicated that feeding HF diets reduced ( ≤ 0.05) ADFI and ADG of pigs compared with feeding LF diets. Pigs fed DFM diets had improved ( ≤ 0.05) G:F compared with pigs fed non-DFM diets. Pigs fed LF diets had greater ( ≤ 0.05) BW at the end of phase 2 compared with pigs fed HF diets. The concentration of VFA in rectum contents was greater ( ≤ 0.05) in pigs fed LF diets than in pigs fed HF diets. The expression of in the rectum of pigs fed HF diets was greater ( ≤ 0.05) than for pigs fed LF diets, and pigs fed DFM-containing diets had an increased ( ≤ 0.05) expression of in the liver. Pigs fed HF diets had greater ( ≤ 0.05) concentrations of urea N in plasma compared with pigs fed LF diets, but dietary fiber and DFM had no effect on plasma concentration of TNF-ɑ. In conclusion, the -based DFM improved overall G:F of weanling pigs, but pigs fed LF diets had greater final BW than pigs fed HF diets.

Effect of Direct-Fed Microbial Dosage on the Fecal Concentrations of Enterohemorrhagic Escherichia coli in Feedlot Cattle.

PubMed

Luedtke, Brandon E; Bosilevac, Joseph M; Harhay, Dayna M; Arthur, Terrance M

2016-04-01

Contamination of beef products by Shiga toxin-producing Escherichia coli is a concern for food safety with a particular subset, the enterohemorrhagic E. coli (EHEC), being the most relevant to human disease. To mitigate food safety risks, preharvest intervention strategies have been implemented with the aim to reduce EHEC in cattle. One class of interventions that has been widely used in feedlots is direct-fed microbials (DFMs), which can contain various dosing rates of probiotic bacteria. Here we compare the use of two different doses of a commercially available DFM on total EHEC load in a commercial feedlot setting. The DFMs used were the standard 10(9) Propionibacterium freudenreichii and 10(6) Lactobacillus acidophilus colony forming units (CFUs)/head/day dose of Bovamine(®) (Nutrition Physiology Company, Guymon, OK) and the higher dose, Bovamine Defend™ (Nutrition Physiology Company), which is dosed at 10(9) P. freudenreichii and 10(9) Lactobacillus acidophilus CFUs/head/day. To analyze the total EHEC fecal concentration, 2200 head of cattle were assigned a DFM feed regimen lasting approximately 5 months. At harvest, 480 head of cattle were sampled using rectoanal mucosal swabs. A quantitative polymerase chain reaction assay targeting ecf1 was used to enumerate the total EHEC fecal concentration for 240 head fed the low-dose DFM and 240 head fed the high-dose DFM. No significant difference (p > 0.05) in the fecal concentration of total EHEC was observed between the two doses. This suggests that using an increased dosage provides no additional reduction in the total EHEC fecal concentration of feedlot cattle compared to the standard dosage.

Dietary marker effects on fecal microbial ecology, fecal VFA, nutrient digestibility coefficients, and growth performance in finishing pigs.

PubMed

Kerr, B J; Weber, T E; Ziemer, C J

2015-05-01

Use of indigestible markers such as Cr2O3, Fe2O3, and TiO2 are commonly used in animal studies to evaluate digesta rate of passage and nutrient digestibility. Yet, the potential impact of indigestible markers on fecal microbial ecology and subsequent VFA generation is not known. Two experiments utilizing a total of 72 individually fed finishing pigs were conducted to describe the impact of dietary markers on fecal microbial ecology, fecal ammonia and VFA concentrations, nutrient digestibility, and pig performance. All pigs were fed a common diet with no marker or with 0.5% Cr2O3, Fe2O3, or TiO2. In Exp. 1, after 33 d of feeding, fresh fecal samples were collected for evaluation of microbial ecology, fecal ammonia and VFA concentrations, and nutrient digestibility, along with measures of animal performance. No differences were noted in total microbes or bacterial counts in pig feces obtained from pigs fed the different dietary markers while Archaea counts were decreased (P = 0.07) in feces obtained from pigs fed the diet containing Fe2O 3compared to pigs fed the control diet. Feeding Cr2O3, Fe2O3, or TiO2 increased fecal bacterial richness (P = 0.03, 0.01, and 0.10; respectively) when compared to pigs fed diets containing no marker, but no dietary marker effects were noted on fecal microbial evenness or the Shannon-Wiener index. Analysis of denaturing gradient gel electrophoresis gels did not reveal band pattern alterations due to inclusion of dietary markers in pig diets. There was no effect of dietary marker on fecal DM, ammonia, or VFA concentrations. Pigs fed diets containing Cr2O3 had greater Ca, Cu, Fe, and P (P ≤ 0.02), but lower Ti ( P= 0.08) digestibility compared to pigs fed the control diet. Pigs fed diets containing Fe2O3 had greater Ca (P = 0.08) but lower Ti (P = 0.01) digestibility compared to pigs fed the control diet. Pigs fed diets containing TiO2 had greater Fe and Zn (P ≤ 0.09), but lower Ti ( P= 0.01) digestibility compared to pigs fed the control diet. In Exp. 2, no effect of dietary marker on pig performance was noted. Overall, the data indicate that the inclusion of Cr2O3, Fe2O3, or TiO2 as digestibility markers have little to no impact on microbial ecology, fecal ammonia or VFA concentrations, nutrient digestibility, or pig growth performance indicating they are suitable for use in digestion studies.

The effect of direct-fed microbial supplementation, as an alternative to antibiotics, on growth performance, intestinal immune status and epithelial barrier protein expression in broiler chickens

USDA-ARS?s Scientific Manuscript database

The objective of this study was to investigate the effects of Bacillus subtilis-based probiotic supplementation in broiler chicken diets on growth performance, feed efficiency, intestinal cytokine and tight junction (TJ) protein mRNA expression. Day-old broiler chicks (n = 140) were randomly assigne...

Dietary Bacillus subtilis-based direct-fed microbials alleviate LPS-induced intestinal immunological stress and improve intestinal barrier gene expression in commercial broiler chickens

USDA-ARS?s Scientific Manuscript database

The present study investigated the effects of B. subtilis-based probiotics on performance, modulation of host inflammatory responses and intestinal barrier integrity of broilers subjected to LPS challenge. Birds at day 0 of age were randomly allocated to one of the 3 dietary treatments - controls, ...

The effects of direct-fed microbial supplementation, as alternative to antibiotics, on growth performance, intestinal immune status and epithelial barrier protein expression in broiler chickens

USDA-ARS?s Scientific Manuscript database

This study was conducted to investigate the effects of Bacillus subtilis supplementation in broiler chicken diets on growth performance, feed efficiency, intestinal cytokine and tight junction (TJ) protein mRNA expression. Day-old broiler chicks (n = 140) were assigned five dietary treatments: basal...

Comparative performances of microbial capacitive deionization cell and microbial fuel cell fed with produced water from the Bakken shale.

PubMed

Shrestha, Namita; Chilkoor, Govinda; Wilder, Joseph; Ren, Zhiyong Jason; Gadhamshetty, Venkataramana

2018-06-01

This study evaluates and compares the performance of microbial fuel cells (MFCs) and microbial capacitive deionization cells (MCDCs) fed with wastewater produced from the Bakken shale. The produced water was characterized by high levels of dissolved solids and chemical oxygen demand (COD). Two-compartment MFCs and three-compartment MCDCs were evaluated under batch-fed mode using mixed microbial consortia in the anode, ferricyanide in the cathode, and produced water as the electrolyte in the anode and capacitive deionization units. COD removal in the MFCs was 88%, while that in the MCDCs was limited to 76%. The lower performance of the MCDCs was due to the large impedance (6600 Ω cm 2 ) compared with the MFCs (870 Ω cm 2 ). However, the MCDCs achieved two-fold higher removal of dissolved solids. Both the MFCs and MCDCs suffered from a higher impedance induced by fouling in the latter stages of the operation. Copyright © 2018 Elsevier B.V. All rights reserved.

Microbial production of volatile sulphur compounds in the large intestine of pigs fed two different diets

USDA-ARS?s Scientific Manuscript database

Only little is known about the microbial production of volatile sulphur compounds (VSC) in the 18 gastrointestinal tract, the dietary influence, and the magnitude of this production. To investigate intestinal VSC production in more detail, pigs were fed diets based on either wheat and barley (CONTRO...

Shewanella oneidensis in a lactate-fed pure-culture and a glucose-fed co-culture with Lactococcus lactis with an electrode as electron acceptor

USDA-ARS?s Scientific Manuscript database

Bioelectrochemical systems (BESs) employing mixed microbial communities as biocatalysts are gaining importance as potential renewable energy, bioremediation, or biosensing devices. While we are beginning to understand how individual microbial species interact with an electrode as electron donor, li...

Current Status of the Preharvest Application of Pro- and Prebiotics to Farm Animals to Enhance the Microbial Safety of Animal Products.

PubMed

Joerger, Rolf D; Ganguly, Arpeeta

2017-01-01

The selection of microorganisms that act as probiotics and feed additives that act as prebiotics is an ongoing research effort, but a sizable range of commercial pro-, pre- and synbiotic (combining pro- and prebiotics) products are already available and being used on farms. A survey of the composition of commercial products available in the United States revealed that Lactobacillus acidophilus, Enterococcus faecium, and Bacillus subtilis were the three most common species in probiotic products. Of the nearly 130 probiotic products (also called direct-fed microbials) for which information was available, about 50 also contained yeasts or molds. The focus on these particular bacteria and eukaryotes is due to long-standing ideas about the benefits of such strains, research data on effectiveness primarily in laboratory or research farm settings, and regulations that dictate which microorganisms or feed additives can be administered to farm animals. Of the direct-fed microbials, only six made a claim relating to food safety or competitive exclusion of pathogens. None of the approximately 50 prebiotic products mentioned food safety in their descriptions. The remainder emphasized enhancement of animal performance such as weight gain or overall animal health. The reason why so few products carry food safety-related claims is the difficulties in establishing unambiguous cause and effect relationships between the application of such products in varied and constantly changing farm environments and improved food safety of the end product.

Electricity generation in a membrane-less microbial fuel cell with down-flow feeding onto the cathode.

PubMed

Zhu, Feng; Wang, Wancheng; Zhang, Xiaoyan; Tao, Guanhong

2011-08-01

A novel membrane-less microbial fuel cell (MFC) with down-flow feeding was constructed to generate electricity. Wastewater was fed directly onto the cathode which was horizontally installed in the upper part of the MFC. Oxygen could be utilized readily from the air. The concentration of dissolved oxygen in the influent wastewater had little effect on the power generation. A saturation-type relationship was observed between the initial COD and the power generation. The influent flow rate could affect greatly the power density. Fed by the synthetic glucose wastewater with a COD value of 3500 mg/L at a flow rate of 4.0 mL/min, the developed MFC could produce a maximum power density of 37.4 mW/m(2). Its applicability was further evaluated by the treatment of brewery wastewater. The system could be scaled up readily due to its simple configuration, easy operation and relatively high power density. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of dietary fiber on microbial activity and microbial gas production in various regions of the gastrointestinal tract of pigs.

PubMed Central

Jensen, B B; Jørgensen, H

1994-01-01

The microbial activity, composition of the gas phase, and gas production rates in the gastrointestinal tract of pigs fed either a low- or a high-fiber diet were investigated. Dense populations of culturable anaerobic bacteria, high ATP concentrations, and high adenylate energy charges were found for the last third of the small intestine, indicating that substantial microbial activity takes place in that portion of the gut. The highest microbial activity (highest bacterium counts, highest ATP concentration, high adenylate energy charge, and low pH) was found in the cecum and proximal colon. Greater microbial activity was found in the stomach and all segments of the hindgut in the pigs fed the high-fiber diet than in the pigs fed the low-fiber diet. Considerable amounts of O2 were found in the stomach (around 5%), while the content of O2 in gas samples taken from all other parts of the gastrointestinal tract was < 1%. The highest concentrations and highest production rates for H2 were found in the last third of the small intestine. No methane could be detected in the stomach or the small intestine. The rate of production and concentration of methane in the cecum and the proximal colon were low, followed by a steady increase in the successive segments of the hindgut. A very good correlation between in vivo and in vitro measurements of methane production was found. The amount of CH4 produced by pigs fed the low-fiber diet was 1.4 liters/day per animal. Substantially larger amounts of CH4 were produced by pigs fed the high-fiber diet (12.5 liters/day)(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8031085

Pan-Arctic patterns of planktonic heterotrophic microbial abundance and processes: Controlling factors and potential impacts of warming

NASA Astrophysics Data System (ADS)

Maranger, Roxane; Vaqué, Dolors; Nguyen, Dan; Hébert, Marie-Pier; Lara, Elena

2015-12-01

The Arctic Ocean is rapidly changing where increasing water temperatures and rapid loss of summer sea-ice will likely influence the structure and functioning of the entire ecosystem. The aim of this study was to synthesize the current state of knowledge on microbial abundances and processes from a regional Pan-Arctic perspective, characterize regulating factors and attempt to predict how patterns may change under a warming scenario. Here we identify some generalized patterns of different microbial variables between the Pacific-fed and the Atlantic-fed sectors of the Arctic Ocean. Bacterial production (BP), abundance and grazing rates by protists (GT) were all higher in the Atlantic-fed region. Bacterial loss by viral lyses (VL) was proportionally more important in the Pacific-fed sector, suggesting a reduced C transfer efficiency within the microbial loop of that region. Using a cross-comparative approach and all available data to build Arrhenius plots, we found a differential response to warming temperatures among various microbial processes. BP and GT responded similarly and more strongly to increases in temperature than VL did, suggesting a shift in the overall influence of viral mortality under a warming scenario. However, together with temperature, resource-related factors also exerted an influence in regulating these rates. We identified large information gaps for more classically studied microbial variable from several Arctic seas. Furthermore, there is limited information on less conventional pathways such as grazing by mixotrophic species, which may be playing a significant role in Arctic microbial trophodynamics. Although generalized patterns could be elucidated, more information is needed to predict and understand how a changing Arctic will alter microbial C pathways and major biogeochemical cycles on regional and seasonal scales.

Long-term exposure to benzalkonium chloride disinfectants results in change of microbial community structure and increased antimicrobial resistance.

PubMed

Tandukar, Madan; Oh, Seungdae; Tezel, Ulas; Konstantinidis, Konstantinos T; Pavlostathis, Spyros G

2013-09-03

The effect of benzalkonium chlorides (BACs), a widely used class of quaternary ammonium disinfectants, on microbial community structure and antimicrobial resistance was investigated using three aerobic microbial communities: BACs-unexposed (DP, fed a mixture of dextrin/peptone), BACs-exposed (DPB, fed a mixture of dextrin/peptone and BACs), and BACs-enriched (B, fed only BACs). Long-term exposure to BACs reduced community diversity and resulted in the enrichment of BAC-resistant species, predominantly Pseudomonas species. Exposure of the two microbial communities to BACs significantly decreased their susceptibility to BACs as well as three clinically relevant antibiotics (penicillin G, tetracycline, ciprofloxacin). Increased resistance to BACs and penicillin G of the two BACs-exposed communities is predominantly attributed to degradation or transformation of these compounds, whereas resistance to tetracycline and ciprofloxacin is largely due to the activity of efflux pumps. Quantification of several key multidrug resistance genes showed a much higher number of copies of these genes in the DPB and B microbial communities compared to the DP community. Collectively, our findings indicate that exposure of a microbial community to BACs results in increased antibiotic resistance, which has important implications for both human and environmental health.

Metagenomics approach to the study of the gut microbiome structure and function in zebrafish Danio rerio fed with gluten formulated diet.

PubMed

Koo, Hyunmin; Hakim, Joseph A; Powell, Mickie L; Kumar, Ranjit; Eipers, Peter G; Morrow, Casey D; Crowley, Michael; Lefkowitz, Elliot J; Watts, Stephen A; Bej, Asim K

2017-04-01

In this study, we report the gut microbial composition and predictive functional profiles of zebrafish, Danio rerio, fed with a control formulated diet (CFD), and a gluten formulated diet (GFD) using a metagenomics approach and bioinformatics tools. The microbial communities of the GFD-fed D. rerio displayed heightened abundances of Legionellales, Rhizobiaceae, and Rhodobacter, as compared to the CFD-fed counterparts. Predicted metagenomics of microbial communities (PICRUSt) in GFD-fed D. rerio showed KEGG functional categories corresponding to bile secretion, secondary bile acid biosynthesis, and the metabolism of glycine, serine, and threonine. The CFD-fed D. rerio exhibited KEGG functional categories of bacteria-mediated cobalamin biosynthesis, which was supported by the presence of cobalamin synthesizers such as Bacteroides and Lactobacillus. Though these bacteria were absent in GFD-fed D. rerio, a comparable level of the cobalamin biosynthesis KEGG functional category was observed, which could be contributed by the compensatory enrichment of Cetobacterium. Based on these results, we conclude D. rerio to be a suitable alternative animal model for the use of a targeted metagenomics approach along with bioinformatics tools to further investigate the relationship between the gluten diet and microbiome profile in the gut ecosystem leading to gastrointestinal diseases and other undesired adverse health effects. Copyright © 2017. Published by Elsevier B.V.

Influence of a direct-fed microbial and xylanase enzyme on the dietary energy uptake efficiency and performance of broiler chickens.

PubMed

Murugesan, Ganapathi Raj; Persia, Michael E

2015-09-01

Efficacy of a multi-strain direct-fed microbial product (PoultryStar(®) ME; PS) and a xylanase enzyme product on the dietary energy utilization efficiency and resulting performance in broiler chickens was evaluated. Apart from performance parameters, cecal and serum metabolites and activities of hepatic enzymes involved in energy metabolism were also determined. Ross 308 chicks were fed one of four experimental diets [control (CON), CON + PS, CON + xylanase and CON + PS + xylanase] using a 2 × 2 factorial arrangement from 1-21 days of age. Cecal proportions of propionate and butyrate, as well as total short-chain fatty acid concentration were increased (P <0.01) by PS suggesting increased fermentation of dietary fiber. Both additives reduced (P <0.01) serum non-esterified free fatty acids, while PS reduced (P <0.01) serum triglyceride. Hepatic glycogen concentration was increased (P <0.01) by both additives. Changes in these serum metabolites and hepatic glycogen indicate the influence of additives in swiftly transitioning the birds from fasting to feeding metabolism. The activity of hepatic glucose-6-phosphate dehydrogenase (G6PDH) was increased (P <0.01) by PS. Elevated hepatic glycogen and G6PDH activity indicate increased glucose-sparing potential. Feed conversion ratio (FCR) was lowered by both additives, while the magnitude of reduction was higher with the combination. The combination worked synergistically, compared to their individual effects, to increase dietary energy uptake and hepatic energy retention. The combination additively increased the FCR, suggesting involvement of synergistic modes of actions. © 2014 Society of Chemical Industry.

Comparative effects of direct-fed microbials alone or with a trace minerals supplements on the productive performance, blood metabolites, and antioxidant status in grazing Awassi lambs.

PubMed

Alhidary, I A; Abdelrahman, M M; Khan, R U

2016-12-01

Twenty Awassi lambs were used to find the effects of direct-fed microbials (DFM) and long-acting trace minerals rumen bolus (TMB) supplements on performance, blood biochemical variables, and antioxidant status of the lambs under grazing conditions. The lambs were randomly distributed into four groups as follows: (1) untreated, (2) oral dose of 5 mL DFM, (3) TMB, or (4) oral dose of 5 mL DFM and TMB. The treatments were carried out for 90 days. Supplementation with TMB significantly increased (P < 0.05) average daily gain (ADG) and feed efficiency compared with the control. A significant (P < 0.05) increase in blood albumin in the DFM and a significant (P < 0.05) decrease in aspartate aminotrasferase were found in the lambs supplemented with TMB alone or in combination with DFM. Supplementing lambs with TMB resulted in higher glutathione peroxidase, total antioxidant capacity (P < 0.001) and activity of superoxide dismutase (P < 0.05) compared with no supplementation and supplementation with DFM only. In conclusion, TMB supplementation had a positive impact on performance traits and the antioxidant system of the lambs under grazing condition.

Response of Methanogenic Microbial Communities to Desiccation Stress in Flooded and Rain-Fed Paddy Soil from Thailand

PubMed Central

Reim, Andreas; Hernández, Marcela; Klose, Melanie; Chidthaisong, Amnat; Yuttitham, Monthira; Conrad, Ralf

2017-01-01

Rice paddies in central Thailand are flooded either by irrigation (irrigated rice) or by rain (rain-fed rice). The paddy soils and their microbial communities thus experience permanent or arbitrary submergence, respectively. Since methane production depends on anaerobic conditions, we hypothesized that structure and function of the methanogenic microbial communities are different in irrigated and rain-fed paddies and react differently upon desiccation stress. We determined rates and relative proportions of hydrogenotrophic and aceticlastic methanogenesis before and after short-term drying of soil samples from replicate fields. The methanogenic pathway was determined by analyzing concentrations and δ13C of organic carbon and of CH4 and CO2 produced in the presence and absence of methyl fluoride, an inhibitor of aceticlastic methanogenesis. We also determined the abundance (qPCR) of genes and transcripts of bacterial 16S rRNA, archaeal 16S rRNA and methanogenic mcrA (coding for a subunit of the methyl coenzyme M reductase) and the composition of these microbial communities by T-RFLP fingerprinting and/or Illumina deep sequencing. The abundances of genes and transcripts were similar in irrigated and rain-fed paddy soil. They also did not change much upon desiccation and rewetting, except the transcripts of mcrA, which increased by more than two orders of magnitude. In parallel, rates of CH4 production also increased, in rain-fed soil more than in irrigated soil. The contribution of hydrogenotrophic methanogenesis increased in rain-fed soil and became similar to that in irrigated soil. However, the relative microbial community composition on higher taxonomic levels was similar between irrigated and rain-fed soil. On the other hand, desiccation and subsequent anaerobic reincubation resulted in systematic changes in the composition of microbial communities for both Archaea and Bacteria. It is noteworthy that differences in the community composition were mostly detected on the level of operational taxonomic units (OTUs; 97% sequence similarity). The treatments resulted in change of the relative abundance of several archaeal OTUs. Some OTUs of Methanobacterium, Methanosaeta, Methanosarcina, Methanocella and Methanomassiliicoccus increased, while some of Methanolinea and Methanosaeta decreased. Bacterial OTUs within Firmicutes, Cyanobacteria, Planctomycetes and Deltaproteobacteria increased, while OTUs within other proteobacterial classes decreased. PMID:28529503

Nitrifying biomass characterization and monitoring during bioaugmentation in a membrane bioreactor.

PubMed

D'Anteo, Sibilla; Mannucci, Alberto; Meliani, Matteo; Verni, Franco; Petroni, Giulio; Munz, Giulio; Lubello, Claudio; Mori, Gualtiero; Vannini, Claudia

2015-01-01

A membrane bioreactor (MBR), fed with domestic wastewater, was bioaugmented with nitrifying biomass selected in a side-stream MBR fed with a synthetic high nitrogen-loaded influent. Microbial communities evolution was monitored and comparatively analysed through an extensive bio-molecular investigation (16S rRNA gene library construction and terminal-restriction fragment length polymorphism techniques) followed by statistical analyses. As expected, a highly specialized nitrifying biomass was selected in the side-stream reactor fed with high-strength ammonia synthetic wastewater. The bioaugmentation process caused an increase of nitrifying bacteria of the genera Nitrosomonas (up to more than 30%) and Nitrobacter in the inoculated MBR reactor. The overall structure of the microbial community changed in the mainstream MBR as a result of bioaugmentation. The effect of bioaugmentation in the shift of the microbial community was also verified through statistical analysis.

Groundwater-fed Iron-rich Microbial Mats in a Freshwater Creek: Growth Cycles and Fossilization Potential of Microbial Features

NASA Astrophysics Data System (ADS)

Schieber, J.

2004-03-01

Study of modern microbial mats produced by iron precipitating microbes. Aging and compaction experiments to evaluate fossilization potential and likelihood to recognize these deposits in the rock record.

High-performance recombinant protein production with Escherichia coli in continuously operated cascades of stirred-tank reactors.

PubMed

Schmideder, Andreas; Weuster-Botz, Dirk

2017-07-01

The microbial expression of intracellular, recombinant proteins in continuous bioprocesses suffers from low product concentrations. Hence, a process for the intracellular production of photoactivatable mCherry with Escherichia coli in a continuously operated cascade of two stirred-tank reactors was established to separate biomass formation (first reactor) and protein expression (second reactor) spatially. Cascades of miniaturized stirred-tank reactors were implemented, which enable the 24-fold parallel characterization of cascade processes and the direct scale-up of results to the liter scale. With PAmCherry concentrations of 1.15 g L -1 cascades of stirred-tank reactors improved the process performance significantly compared to production processes in chemostats. In addition, an optimized fed-batch process was outperformed regarding space-time yield (149 mg L -1  h -1 ). This study implicates continuous cascade processes to be a promising alternative to fed-batch processes for microbial protein production and demonstrates that miniaturized stirred-tank reactors can reduce the timeline and costs for cascade process characterization.

Irradiation of diets fed to captive exotic felids: microbial destruction, consumption, and fecal consistency.

PubMed

Crissey, S D; Slifka, K A; Jacobsen, K L; Shumway, P J; Mathews, R; Harper, J

2001-09-01

Two frozen, raw horse meat-based diets fed to captive exotic felids at Brookfield Zoo were irradiated to determine the extent of microbial destruction and whether radiation treatment would affect consumption and/or fecal consistency in exotic cats. Fifteen cats, two African lions (Panthera leo), two Amur tigers (Panthera tigris altaica), one Amur leopard (Panthera pardus orientalis), two clouded leopards (Neofelis nebulosa), two caracals (Felis caracal), one bobcat (Felis rufus), and five fishing cats (Felis viverrinus), housed at Brookfield Zoo were fed nonirradiated and irradiated raw diets containing horse meat with cereal products and fortified with nutrients: Nebraska Brand Feline and/or Canine Diet (Animal Spectrum, North Platte, Nebraska 69103, USA). Baseline data were obtained during a 2-wk control period (nonirradiated diets), which was followed by a 4-wk period of feeding comparable irradiated diets. Feed intake and fecal consistency data were collected. An estimated radiation dose range of 0.5-3.9 kilograys reduced most microbial populations, depending on specific diet and microbe type. Irradiation had no overall effect on either feed consumption or fecal consistency in captive exotic cats, regardless of species, age, sex, or body mass. Data indicate that irradiation of frozen horse meat-based diets (packaged in 2.2-kg portions) result in microbial destruction in these products but that product storage time between irradiation and sampling may also affect microbial reduction. However, irradiation would be an appropriate method for reducing potentially pathologic bacteria in raw meat fed to exotic cats.

Diets of differentially processed wheat alter ruminal fermentation parameters and microbial populations in beef cattle.

PubMed

Jiang, S Z; Yang, Z B; Yang, W R; Li, Z; Zhang, C Y; Liu, X M; Wan, F C

2015-11-01

The influences of differently processed wheat products on rumen fermentation, microbial populations, and serum biochemistry profiles in beef cattle were studied. Four ruminally cannulated Limousin × Luxi beef cattle (400 ± 10 kg) were used in the experiment with a 4 × 4 Latin square design. The experimental diets contained (on a DM basis) 60% corn silage as a forage source and 40% concentrate with 4 differently processed wheat products (extruded, pulverized, crushed, and rolled wheat). Concentrations of ruminal NH-N and microbial protein (MCP) in cattle fed crushed and rolled wheat were greater ( < 0.05) than the corresponding values in cattle fed pulverized and extruded wheat. Ruminal concentrations of total VFA and acetate and the ratio of acetate to propionate decreased ( < 0.05) with increased geometric mean particle size (geometric mean diameter) of processed wheat, except for extruded wheat; cattle fed extruded wheat had the lowest concentrations of total VFA and acetate among all treatments. The relative abundance of , , ciliated protozoa, and was lower in cattle fed the pulverized wheat diet than in the other 3 diets ( < 0.05), whereas the relative abundance of was decreased in cattle fed extruded wheat compared with cattle fed crushed and rolled wheat ( < 0.05). No treatment effect was obtained for serum enzyme activity and protein concentration ( > 0.05). Our findings suggest that the method of wheat processing could have a significant effect on ruminal fermentation parameters and microbial populations in beef cattle and that crushed and rolled processing is better in terms of ruminal NH-N and MCP content, acetate-to-propionate ratio, and relative abundance of rumen microorganisms.

Breast-fed and bottle-fed infant rhesus macaques develop distinct gut microbiotas and immune systems

PubMed Central

Ardeshir, Amir; Narayan, Nicole R.; Méndez-Lagares, Gema; Lu, Ding; Rauch, Marcus; Huang, Yong; Van Rompay, Koen K. A.; Lynch, Susan V.; Hartigan-O'Connor, Dennis J.

2015-01-01

Diet has a strong influence on the intestinal microbiota in both humans and animal models. It is well established that microbial colonization is required for normal development of the immune system and that specific microbial constituents prompt the differentiation or expansion of certain immune cell subsets. Nonetheless, it has been unclear how profoundly diet might shape the primate immune system or how durable the influence might be. We show that breast-fed and bottle-fed infant rhesus macaques develop markedly different immune systems, which remain different 6 months after weaning when the animals begin receiving identical diets. In particular, breast-fed infants develop robust populations of memory T cells as well as T helper 17 (TH17) cells within the memory pool, whereas bottle-fed infants do not. These findings may partly explain the variation in human susceptibility to conditions with an immune basis, as well as the variable protection against certain infectious diseases. PMID:25186175

Effect of different sulfadimidine addition methods on its degradation behaviour in swine manure.

PubMed

Ren, Tian-Tian; Li, Xiao-Yang; Wang, Yan; Zou, Yong-De; Liao, Xin-Di; Liang, Juan-Boo; Wu, Yin-Bao

2017-03-01

Sulfadimidine (SM2) is commonly used in the swine industry and enters the environment via faeces. In recent years, advances in the ecotoxicology of SM2 have become a popular research interest with two common research methods including swine manure collection from swine fed with a diet containing SM2 and directly adding SM2. The purpose of this experiment was to compare SM2 degradation behaviour in pig manure with two different SM2 addition methods. The results showed that the degradation half-lives of SM2 in manure from SM2-fed swine treatment were 33.2 and 32.0 days at the initial addition level of SM2 at 32.1 and 64.3 mg/kg, respectively. This was significantly longer than that in manure directly adding SM2 treatment with the half-lives of 21.4 and 14.8 days. The metabolite of SM2 N 4 -acetyl-sulfamethazine occurred in manure from SM2-fed swine treatment but was not detected in directly adding SM2 treatment. The pH in manure from SM2-fed swine treatment was significantly lower than that in directly adding SM2 treatment, but the values of organic carbon, total nitrogen, and electrical conductivity in manure from SM2-fed swine treatment were significantly higher than those in manure directly adding SM2 treatment. Meanwhile, although the copy number of bacteria had no significant difference between two treatments, there was a significant difference in bacteria diversity. Results of the present study demonstrated that the presence of the metabolites, chemical property, and microbial diversity might be the reason for different SM2 degradation behaviours on different addition methods. Thus, the method using manure with SM2 collected from swine could obtain more accurate results for the ecotoxicological study of SM2.

Effect of Probiotics/Prebiotics on Cattle Health and Productivity.

PubMed

Uyeno, Yutaka; Shigemori, Suguru; Shimosato, Takeshi

2015-01-01

Probiotics/prebiotics have the ability to modulate the balance and activities of the gastrointestinal (GI) microbiota, and are, thus, considered beneficial to the host animal and have been used as functional foods. Numerous factors, such as dietary and management constraints, have been shown to markedly affect the structure and activities of gut microbial communities in livestock animals. Previous studies reported the potential of probiotics and prebiotics in animal nutrition; however, their efficacies often vary and are inconsistent, possibly, in part, because the dynamics of the GI community have not been taken into consideration. Under stressed conditions, direct-fed microbials may be used to reduce the risk or severity of scours caused by disruption of the normal intestinal environment. The observable benefits of prebiotics may also be minimal in generally healthy calves, in which the microbial community is relatively stable. However, probiotic yeast strains have been administered with the aim of improving rumen fermentation efficiency by modulating microbial fermentation pathways. This review mainly focused on the benefits of probiotics/prebiotics on the GI microbial ecosystem in ruminants, which is deeply involved in nutrition and health for the animal.

Effect of Probiotics/Prebiotics on Cattle Health and Productivity

PubMed Central

Uyeno, Yutaka; Shigemori, Suguru; Shimosato, Takeshi

2015-01-01

Probiotics/prebiotics have the ability to modulate the balance and activities of the gastrointestinal (GI) microbiota, and are, thus, considered beneficial to the host animal and have been used as functional foods. Numerous factors, such as dietary and management constraints, have been shown to markedly affect the structure and activities of gut microbial communities in livestock animals. Previous studies reported the potential of probiotics and prebiotics in animal nutrition; however, their efficacies often vary and are inconsistent, possibly, in part, because the dynamics of the GI community have not been taken into consideration. Under stressed conditions, direct-fed microbials may be used to reduce the risk or severity of scours caused by disruption of the normal intestinal environment. The observable benefits of prebiotics may also be minimal in generally healthy calves, in which the microbial community is relatively stable. However, probiotic yeast strains have been administered with the aim of improving rumen fermentation efficiency by modulating microbial fermentation pathways. This review mainly focused on the benefits of probiotics/prebiotics on the GI microbial ecosystem in ruminants, which is deeply involved in nutrition and health for the animal. PMID:26004794

Microbial fuel cells for direct electrical energy recovery from urban wastewaters.

PubMed

Capodaglio, A G; Molognoni, D; Dallago, E; Liberale, A; Cella, R; Longoni, P; Pantaleoni, L

2013-01-01

Application of microbial fuel cells (MFCs) to wastewater treatment for direct recovery of electric energy appears to provide a potentially attractive alternative to traditional treatment processes, in an optic of costs reduction, and tapping of sustainable energy sources that characterizes current trends in technology. This work focuses on a laboratory-scale, air-cathode, and single-chamber MFC, with internal volume of 6.9 L, operating in batch mode. The MFC was fed with different types of substrates. This study evaluates the MFC behaviour, in terms of organic matter removal efficiency, which reached 86% (on average) with a hydraulic retention time of 150 hours. The MFC produced an average power density of 13.2 mW/m(3), with a Coulombic efficiency ranging from 0.8 to 1.9%. The amount of data collected allowed an accurate analysis of the repeatability of MFC electrochemical behaviour, with regards to both COD removal kinetics and electric energy production.

The rumen microbiome as a reservoir of antimicrobial resistance and pathogenicity genes is directly affected by diet in beef cattle.

PubMed

Auffret, Marc D; Dewhurst, Richard J; Duthie, Carol-Anne; Rooke, John A; John Wallace, R; Freeman, Tom C; Stewart, Robert; Watson, Mick; Roehe, Rainer

2017-12-11

The emergence and spread of antimicrobial resistance is the most urgent current threat to human and animal health. An improved understanding of the abundance of antimicrobial resistance genes and genes associated with microbial colonisation and pathogenicity in the animal gut will have a major role in reducing the contribution of animal production to this problem. Here, the influence of diet on the ruminal resistome and abundance of pathogenicity genes was assessed in ruminal digesta samples taken from 50 antibiotic-free beef cattle, comprising four cattle breeds receiving two diets containing different proportions of concentrate. Two hundred and four genes associated with antimicrobial resistance (AMR), colonisation, communication or pathogenicity functions were identified from 4966 metagenomic genes using KEGG identification. Both the diversity and abundance of these genes were higher in concentrate-fed animals. Chloramphenicol and microcin resistance genes were dominant in samples from forage-fed animals (P < 0.001), while aminoglycoside and streptomycin resistances were enriched in concentrate-fed animals. The concentrate-based diet also increased the relative abundance of Proteobacteria, which includes many animal and zoonotic pathogens. A high ratio of Proteobacteria to (Firmicutes + Bacteroidetes) was confirmed as a good indicator for rumen dysbiosis, with eight cases all from concentrate-fed animals. Finally, network analysis demonstrated that the resistance/pathogenicity genes are potentially useful as biomarkers for health risk assessment of the ruminal microbiome. Diet has important effects on the complement of AMR genes in the rumen microbial community, with potential implications for human and animal health.

Protein recycling in growing rabbits: contribution of microbial lysine to amino acid metabolism.

PubMed

Belenguer, Alvaro; Balcells, Joaquim; Guada, Jose A; Decoux, Marc; Milne, Eric

2005-11-01

To study the absorption of microbial lysine in growing rabbits, a labelled diet (supplemented with (15)NH4Cl) was administered to six animals (group ISOT); a control group (CTRL, four rabbits) received a similar, but unlabelled, diet. Diets were administered for 30 d. An additional group of six animals were fed the unlabelled diet for 20 d and then the labelled diet for 10 d while wearing a neck collar to avoid caecotrophy (group COLL), in order to discriminate it from direct intestinal absorption. At day 30 animals were slaughtered and caecal bacteria and liver samples taken. The (15)N enrichment in amino acids of caecal bacteria and liver were determined by GC-combustion/isotope ratio MS. Lysine showed a higher enrichment in caecal microflora (0.925 atom% excess, APE) than liver (0.215 APE) in group ISOT animals, confirming the double origin of body lysine: microbial and dietary. The COLL group showed a much lower enrichment in tissue lysine (0.007 (se 0.0029) APE for liver). Any enrichment in the latter animals was due to direct absorption of microbial lysine along the digestive tract, since recycling of microbial protein (caecotrophy) was avoided. In such conditions liver enrichment was low, indicating a small direct intestinal absorption. From the ratio of [(15)N]lysine enrichment between liver and bacteria the contribution of microbes to body lysine was estimated at 23 %, with 97 % of this arising through caecotrophy. Absorption of microbial lysine through caecotrophy was 119 (se 4.0) mg/d, compared with 406 (se 1.8) mg/d available from the diet. This study confirms the importance of caecotrophy in rabbit nutrition (15 % of total protein intake).

Rare but active taxa contribute to community dynamics of benthic biofilms in glacier-fed streams.

PubMed

Wilhelm, Linda; Besemer, Katharina; Fasching, Christina; Urich, Tim; Singer, Gabriel A; Quince, Christopher; Battin, Tom J

2014-08-01

Glaciers harbour diverse microorganisms, which upon ice melt can be released downstream. In glacier-fed streams microorganisms can attach to stones or sediments to form benthic biofilms. We used 454-pyrosequencing to explore the bulk (16S rDNA) and putatively active (16S rRNA) microbial communities of stone and sediment biofilms across 26 glacier-fed streams. We found differences in community composition between bulk and active communities among streams and a stronger congruence between biofilm types. Relative abundances of rRNA and rDNA were positively correlated across different taxa and taxonomic levels, but at lower taxonomic levels, the higher abundance in either the active or the bulk communities became more apparent. Here, environmental variables played a minor role in structuring active communities. However, we found a large number of rare taxa with higher relative abundances in rRNA compared with rDNA. This suggests that rare taxa contribute disproportionately to microbial community dynamics in glacier-fed streams. Our findings propose that high community turnover, where taxa repeatedly enter and leave the 'seed bank', contributes to the maintenance of microbial biodiversity in harsh ecosystems with continuous environmental perturbations, such as glacier-fed streams. © 2014 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

A comparison of faecal microbial populations of South African Windsnyer-type indigenous pigs (SAWIPs) and Large White × Landrace (LW × LR) crosses fed diets containing ensiled maize cobs.

PubMed

Kanengoni, Arnold T; Chimonyo, Michael; Tasara, Taurai; Cormican, Paul; Chapwanya, Aspinas; Ndimba, Bongani K; Dzama, Kennedy

2015-07-01

Faecal microbial communities in South African Windsnyer-type indigenous pigs (SAWIPs) and Large White × Landrace (LW × LR) crosses were investigated using high-throughput sequencing of the 16S rDNA genes. The faecal microbial communities in LW × LR crosses and SAWIPs fed control (CON) and high maize cob (HMC) diets were evaluated through parallel sequencing of 16S rDNA genes. Butrivibrio, Faecalibacterium and Desulfovibrio, although present in LW × LR pigs, were absent from the SAWIP microbial community. Bacteroides, Succiniclasticum, Peptococcus and Akkermansia were found in SAWIPs but not in LW × LR crosses. The ratios of Bacteroidia to Clostridia on the CON and HMC diets were similar (0.37 versus 0.39) in SAWIPs but different (0.24 versus 0.1) in LW × LR crosses. The faecal microbial profiles determined were different between the LW × LR and SAWIP breeds but not between pigs fed the CON and HMC diets. The composition of faecal bacterial communities in SAWIPs was determined for the first time. The differences in microbial communities detected may explain the enhanced ability of SAWIPs to digest fibrous diets compared with the LW × LR crosses. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of bacterial direct-fed microbials on ruminal fermentation, blood variables, and the microbial populations of feedlot cattle.

PubMed

Ghorbani, G R; Morgavi, D P; Beauchemin, K A; Leedle, J A Z

2002-07-01

A study was conducted to determine whether bacterial direct-fed microbials (DFM) could be used to minimize the risk of acidosis in feedlot cattle receiving high concentrate diets. Six ruminally cannulated steers, previously adapted to a high concentrate diet, were used in a double 3 x 3 Latin square to study the effects of DFM on feed intake, ruminal pH, and ruminal and blood characteristics. Steers were provided ad libitum access to a diet containing steam-rolled barley, barley silage, and a protein-mineral supplement at 87, 9, and 4% (DM basis), respectively. Treatments were as follows: control, Propionibacterium P15 (P15), and Propionibacterium P15 and Enterococcus faecium EF212 (PE). The bacterial treatments (10(9) cfu/g) plus whey powder carrier, or whey powder alone for control, were top-dressed once daily at the time of feeding (10 g/[steer/d]). Periods consisted of 2 wk of adaptation and 1 wk of measurements. Ruminal pH was continuously measured for 6 d using indwelling electrodes. Dry matter intake and ruminal pH (mean, minimum, hours, and area pH < 5.8 or < 5.5) were not affected by treatment (P > 0.05). However, supplementation with P15 increased protozoal numbers (P < 0.05) with a concomitant increase in ruminal NH3 concentration (P < 0.01) and a decrease in the number of amylolytic bacteria (P < 0.05) compared with the control. Streptococcus bovis, enumerated using a selective medium, was numerically reduced with supplementation of PE. Although blood pH and blood glucose were not affected by DFM supplementation, steers fed PE had numerically lower concentrations of blood CO2 than control steers, which is consistent with a reduced risk of metabolic acidosis. Although the bacterial DFM used in this study did not induce changes in DMI or ruminal and blood pH, some rumen and blood variables indicated that the bacterial DFM used in this study may decrease the risk of acidosis in feedlot cattle.

Microbial and metabolic signatures of necrotizing enterocolitis in formula-fed piglets

USDA-ARS?s Scientific Manuscript database

Major risk factors for necrotizing enterocolitis (NEC) include premature birth, formula feeding, and microbial colonization of the gastrointestinal tract. We previously showed that feeding formula composed of lactose vs corn syrup solids protects against NEC in preterm pigs, however the microbial an...

Development of an Acetate-Fed or Sugar-Fed Microbial Power Generator for Military Bases

DTIC Science & Technology

2011-01-01

quarter. We tested graphite and stainless steel as anode materials for ARB growth, showing the greater suitability of carbon fibers as anode material...microbial electrolysis cells (MECs) with graphite rods and stainless steel meshes as anodes to select the optimum material for use in MFC modules to...be tested in the future. We selected meshes made from 316-grade stainless steel for these initial studies. We conducted several trials with the MECs

High cell density fed-batch fermentations for lipase production: feeding strategies and oxygen transfer.

PubMed

Salehmin, M N I; Annuar, M S M; Chisti, Y

2013-11-01

This review is focused on the production of microbial lipases by high cell density fermentation. Lipases are among the most widely used of the enzyme catalysts. Although lipases are produced by animals and plants, industrial lipases are sourced almost exclusively from microorganisms. Many of the commercial lipases are produced using recombinant species. Microbial lipases are mostly produced by batch and fed-batch fermentation. Lipases are generally secreted by the cell into the extracellular environment. Thus, a crude preparation of lipases can be obtained by removing the microbial cells from the fermentation broth. This crude cell-free broth may be further concentrated and used as is, or lipases may be purified from it to various levels. For many large volume applications, lipases must be produced at extremely low cost. High cell density fermentation is a promising method for low-cost production: it allows a high concentration of the biomass and the enzyme to be attained rapidly and this eases the downstream recovery of the enzyme. High density fermentation enhances enzyme productivity compared with the traditional submerged culture batch fermentation. In production of enzymes, a high cell density is generally achieved through fed-batch operation, not through perfusion culture which is cumbersome. The feeding strategies used in fed-batch fermentations for producing lipases and the implications of these strategies are discussed. Most lipase-producing microbial fermentations require oxygen. Oxygen transfer in such fermentations is discussed.

Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs.

PubMed

González-Vega, J C; Walk, C L; Stein, H H

2015-05-01

An experiment was conducted to test the hypothesis that differences in the apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) of Ca exist among Ca supplements and that inclusion of microbial phytase increases the ATTD and STTD of Ca. One hundred and four growing barrows (average initial BW of 17.73 ± 2.53 kg) were allotted to a randomized complete block design with 13 dietary treatments and 8 pigs per treatment. A basal diet containing corn, cornstarch, potato protein isolate, soybean oil, calcium carbonate, monosodium phosphate, vitamins, and minerals was formulated. Five additional diets were formulated by adding monocalcium phosphate (MCP), dicalcium phosphate (DCP), calcium carbonate, Lithothamnium calcareum Ca, or a high-Ca sugar beet co-product to the basal diet at the expense of cornstarch. Six additional diets that were similar to the previous 6 diets with the exception that they also contained 500 units per kilogram of microbial phytase were also formulated. A Ca-free diet was used to determine basal endogenous losses of Ca. Feces were collected using the marker-to-marker approach. Results indicated that regardless of inclusion of microbial phytase, MCP had the greatest (P < 0.05) ATTD and STTD of Ca. The ATTD and STTD of Ca in DCP were greater (P < 0.05) than in calcium carbonate, L. calcareumC a, or in the sugar beet co-product, but no differences were observed among the ATTD and STTD of Ca in calcium carbonate, L. calcareum Ca, or sugar beet co-product. Inclusion of microbial phytase increased (P < 0.05) the ATTD and STTD of Ca in the diets, but this was not the case in the Ca supplements. Regardless of inclusion of microbial phytase, the ATTD of P was greater ( P< 0.05) in pigs fed basal, MCP, or DCP diets than in pigs fed calcium carbonate, L. calcareum Ca, or the sugar beet co-product, but pigs fed calcium carbonate diets had greater ( P< 0.05) ATTD of P than pigs fed L. calcareumCa or the sugar beet co-product. Regardless of Ca source, inclusion of microbial phytase increased (P < 0.001) the ATTD of P. In conclusion, MCP has the greatest ATTD and STTD of Ca among the calcium supplements used in this experiment, followed by DCP. Basal, MCP, and DCP diets had greater ATTD of P than the other diets, and inclusion of microbial phytase increased the ATTD and STTD of Ca and the ATTD of P in the diets.

Thermal processing of food reduces gut microbiota diversity of the host and triggers adaptation of the microbiota: evidence from two vertebrates.

PubMed

Zhang, Zhimin; Li, Dapeng

2018-05-31

Adoption of thermal processing of the diet drives human evolution and gut microbiota diversity changes in a dietary habit-dependent manner. However, whether thermal processing of food triggers gut microbial variation remains unknown. Herein, we compared the microbiota of non-thermally processed and thermally processed food (NF and TF) and investigated gut microbiota associated with NF and TF in catfish Silurus meridionalis and C57BL/6 mice to assess effects of thermal processing of food on gut microbiota and to further identify the differences in host responses. We found no differences in overall microbial composition and structure in the pairwise NF and TF, but identified differential microbial communities between food and gut. Both fish and mice fed TF had significantly lower gut microbial diversity than those fed NF. Moreover, thermal processing of food triggered the changes in their microbial communities. Comparative host studies further indicated host species determined gut microbial assemblies, even if fed with the same food. Fusobacteria was the most abundant phylum in the fish, and Bacteroidetes and Firmicutes dominated in the mice. Besides the consistent reduction of Bacteroidetes and the balanced Protebacteria, the response of other dominated gut microbiota in the fish and mice to TF was taxonomically opposite at the phylum level, and those further found at the genus level. Our results reveal that thermal processing of food strongly contributes to the reduction of gut microbial diversity and differentially drives microbial alterations in a host-dependent manner, suggesting specific adaptations of host-gut microbiota in vertebrates responding to thermal processing of food. These findings open a window of opportunity to understand the decline in gut microbial diversity and the community variation in human evolution and provide new insights into the host-specific microbial assemblages associated with the use of processing techniques in food preparation in humans and domesticated animals.

Optimizing the performance of microbial fuel cells fed a combination of different synthetic organic fractions in municipal solid waste.

PubMed

Pendyala, Brahmaiah; Chaganti, Subba Rao; Lalman, Jerald A; Heath, Daniel D

2016-03-01

The objective of this study was to establish the impact of different steam exploded organic fractions in municipal solid waste (MSW) on electricity production using microbial fuel cells (MFCs). In particular, the influence of individual steam exploded liquefied waste components (food waste (FW), paper-cardboard waste (PCW) and garden waste (GW)) and their blends on chemical oxygen demand (COD) removal, columbic efficiency (CE) and microbial diversity was examined using a mixture design. Maximum power densities from 0.56 to 0.83 W m(-2) were observed for MFCs fed with different feedstocks. The maximum COD removed and minimum CE were observed for a GW feed. However, a reverse trend (minimum COD removed and maximum CE) was observed for the FW feed. A maximum COD removal (78%) accompanied with a maximum CE (24%) was observed for a combined feed of FW, PCW plus GW in a 1:1:1 ratio. Lactate, the major byproduct detected, was unutilized by the anodic biofilm community. The organic fraction of municipal solid waste (OFMSW) could serve as a potential feedstock for electricity generation in MFCs; however, elevated protein levels will lead to reduced COD removal. The microbial communities in cultures fed FW and PCW was highly diversified; however, the communities in cultures fed FW or a feed mixture containing high FW levels were similar and dominated by Bacteroidetes and β-proteobacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of Infant Feeding Type on Gut Microbiome Development in Hospitalized Preterm Infants

PubMed Central

Cong, Xiaomei; Judge, Michelle; Xu, Wanli; Diallo, Ana; Janton, Susan; Brownell, Elizabeth A.; Maas, Kendra; Graf, Joerg

2016-01-01

Background Premature infants have a high risk for dysbiosis of the gut microbiome. Mother’s own breastmilk (MOM) has been found to favorably alter gut microbiome composition in infants born at term. Evidence about the influence of feeding type on gut microbial colonization of preterm infants is limited. Objective The purpose of this study was to explore the effect of feeding types on gut microbial colonization of preterm infants in the neonatal intensive care unit (NICU). Methods Thirty-three stable preterm infants were recruited at birth and followed-up for the first 30 days of life. Daily feeding information was used to classify infants into six groups (mother’s own milk [MOM], human donated milk [HDM], formula, MOM+HDM, MOM+Formula, and HDM+forumla) during postnatal days 0–10, 11–20, and 21–30 after birth. Stool samples were collected daily. DNA extracted from stool was used to sequence the 16S rRNA gene. Exploratory data analysis was conducted with a focus on temporal changes of microbial patterns and diversities among infants from different feeding cohorts. Prediction of gut microbial diversity from feeding type was estimated using linear mixed models. Results Preterm infants fed MOM (at least 70% of the total diet) had highest abundance of Clostridiales, Lactobacillales, and Bacillales compared to infants in other feeding groups, whereas infants fed primarily human donor milk or formula had a high abundance of Enterobacteriales compared to infants fed MOM. After controlling for gender, postnatal age, weight and birth gestational age, the diversity of gut microbiome increased over time and was constantly higher in infants fed MOM relative to infants with other feeding types (p < .01). Discussion Mother’s own breast milk benefits gut microbiome development of preterm infants, including balanced microbial community pattern and increased microbial diversity in early life. PMID:28252573

Performance and carcass characteristics of commercial feedlot cattle from a study of vaccine and direct-fed microbial effects on Escherichia col O157:H7 fecal shedding.

PubMed

Cull, C A; Renter, D G; Bello, N M; Ives, S E; Babcock, A H

2015-06-01

The objective of this study was to quantify cattle performance and carcass characteristics associated with administration of a siderophore receptor and porin proteins-based vaccine (VAC) and a direct-fed microbial (DFM), which were originally evaluated for their impact on O157:H7 fecal shedding in a commercial feedlot population. Cattle (P = 17,148) were randomly allocated into 40 pens grouped by allocation dates into 10 complete blocks; pens within block were randomly allocated to control, VAC, DFM, or VAC + DFM treatment groups in a 2 × 2 factorial design. The DFM (Bovamine) was fed daily at the labeled dose of 10 cfu/animal of Lactobacillus acidophilus for the duration of the intervention period (mean = 86.6 d). The VAC cattle were vaccinated on Days 0 and 21 whereas unvaccinated cattle were not given a placebo or rehandled on Day 21. Data were analyzed using general and generalized linear mixed models that accounted for the study design. Main effects of DFM and VAC are reported as there were no significant treatment interactions for any of the outcomes evaluated. Vaccinated cattle had lower total weight gain (P < 0.01), ADG (P = 0.03), and cumulative DMI during the intervention period (P < 0.01) compared with unvaccinated cattle, whereas the DFM increased total weight gain (P = 0.03) and G:F (P = 0.05) during the intervention period. Daily DMI was decreased (P < 0.01) in vaccinated pens compared with unvaccinated pens during a 5-d period immediately following revaccination. After the intervention period was completed, cattle were sorted following the standard operating procedure for the feedlot and all cattle were fed the DFM from that point until harvest. Each steer was individually identified through harvest. At harvest, vaccinated cattle had more total days on feed (P < 0.01) with a larger HCW (P = 0.01) than nonvaccinated cattle, whereas cattle not fed the DFM during the intervention period had a significantly larger HCW (P < 0.01) than those fed the DFM during the intervention period. We conclude that the use of these DFM and vaccine products have differential and independent effects on cattle performance and carcass characteristics in a commercial feedlot setting. Although the magnitude of these effects may vary among production systems, a more comprehensive understanding of the potential production costs of preharvest food safety pathogen control programs is essential if such programs are to be fully adopted in the industry.

Electricity production and microbial biofilm characterization in cellulose-fed microbial fuel cells.

PubMed

Ren, Z; Steinberg, L M; Regan, J M

2008-01-01

Converting biodegradable materials into electricity, microbial fuel cells (MFCs) present a promising technology for renewable energy production in specific applications. Unlike typical soluble substrates that have been used as electron donors in MFC studies, cellulose is unique because it requires a microbial consortium that can metabolize both an insoluble electron donor (cellulose) and electron acceptor (electrode). In this study, electricity generation and the microbial ecology of cellulose-fed MFCs were analyzed using a defined co-culture of Clostridium cellulolyticum and Geobacter sulfurreducens. Fluorescent in situ hybridization and quantitative PCR showed that when particulate MN301 cellulose was used as sole substrate, most Clostridium cells were found adhered to cellulose particles in suspension, while most Geobacter cells were attached to the electrode. By comparison, both bacteria resided in suspension and biofilm samples when soluble carboxymethyl cellulose was used. This distinct function-related distribution of the bacteria suggests an opportunity to optimize reactor operation by settling cellulose and decanting supernatant to extend cellulose hydrolysis and improve cellulose-electricity conversion. (c) IWA Publishing 2008.

Oral microbial profile discriminates breast-fed from formula-fed infants.

PubMed

Holgerson, Pernilla L; Vestman, Nelly R; Claesson, Rolf; Ohman, Carina; Domellöf, Magnus; Tanner, Anne C R; Hernell, Olle; Johansson, Ingegerd

2013-02-01

Little is known about the effect of diet on the oral microbiota of infants, although diet is known to affect the gut microbiota. The aims of the present study were to compare the oral microbiota in breast-fed and formula-fed infants, and investigate growth inhibition of streptococci by infant-isolated lactobacilli. A total of 207 mothers consented to participation of their 3-month-old infants. A total of 146 (70.5%) infants were exclusively and 38 (18.4%) partially breast-fed, and 23 (11.1%) were exclusively formula-fed. Saliva from all of their infants was cultured for Lactobacillus species, with isolate identifications from 21 infants. Lactobacillus isolates were tested for their ability to suppress Streptococcus mutans and S sanguinis. Oral swabs from 73 infants were analysed by the Human Oral Microbe Identification Microarray (HOMIM) and by quantitative polymerase chain reaction for Lactobacillus gasseri. Lactobacilli were cultured from 27.8% of exclusively and partially breast-fed infants, but not from formula-fed infants. The prevalence of 14 HOMIM-detected taxa, and total salivary lactobacilli counts differed by feeding method. Multivariate modelling of HOMIM-detected bacteria and possible confounders clustered samples from breast-fed infants separately from formula-fed infants. The microbiota of breast-fed infants differed based on vaginal or C-section delivery. Isolates of L plantarum, L gasseri, and L vaginalis inhibited growth of the cariogenic S mutans and the commensal S sanguinis: L plantarum >L gasseri >L vaginalis. The microbiota of the mouth differs between 3-month-old breast-fed and formula-fed infants. Possible mechanisms for microbial differences observed include species suppression by lactobacilli indigenous to breast milk.

Metabolic adaptation to a high-fat diet is associated with a change in the gut microbiota.

PubMed

Serino, Matteo; Luche, Elodie; Gres, Sandra; Baylac, Audrey; Bergé, Mathieu; Cenac, Claire; Waget, Aurelie; Klopp, Pascale; Iacovoni, Jason; Klopp, Christophe; Mariette, Jerome; Bouchez, Olivier; Lluch, Jerome; Ouarné, Francoise; Monsan, Pierre; Valet, Philippe; Roques, Christine; Amar, Jacques; Bouloumié, Anne; Théodorou, Vassilia; Burcelin, Remy

2012-04-01

The gut microbiota, which is considered a causal factor in metabolic diseases as shown best in animals, is under the dual influence of the host genome and nutritional environment. This study investigated whether the gut microbiota per se, aside from changes in genetic background and diet, could sign different metabolic phenotypes in mice. The unique animal model of metabolic adaptation was used, whereby C57Bl/6 male mice fed a high-fat carbohydrate-free diet (HFD) became either diabetic (HFD diabetic, HFD-D) or resisted diabetes (HFD diabetes-resistant, HFD-DR). Pyrosequencing of the gut microbiota was carried out to profile the gut microbial community of different metabolic phenotypes. Inflammation, gut permeability, features of white adipose tissue, liver and skeletal muscle were studied. Furthermore, to modify the gut microbiota directly, an additional group of mice was given a gluco-oligosaccharide (GOS)-supplemented HFD (HFD+GOS). Despite the mice having the same genetic background and nutritional status, a gut microbial profile specific to each metabolic phenotype was identified. The HFD-D gut microbial profile was associated with increased gut permeability linked to increased endotoxaemia and to a dramatic increase in cell number in the stroma vascular fraction from visceral white adipose tissue. Most of the physiological characteristics of the HFD-fed mice were modulated when gut microbiota was intentionally modified by GOS dietary fibres. The gut microbiota is a signature of the metabolic phenotypes independent of differences in host genetic background and diet.

Evaluation of a direct-fed microbial product effect on the prevalence and load of Escherichia coli O157:H7 in feedlot cattle.

PubMed

Arthur, Terrance M; Bosilevac, Joseph M; Kalchayanand, Norasak; Wells, James E; Shackelford, Steven D; Wheeler, Tommy L; Koohmaraie, Mohammad

2010-02-01

Direct-fed microbials (DFM) have been identified as potential preharvest interventions for the reduction of foodborne bacterial pathogens such as Escherichia coli O157:H7. This study evaluated the efficacy of a DFM consisting of Bacillus subtilis strain 166 as an antimicrobial intervention strategy for the reduction of prevalence and load of E. coli O157:H7 in feces and on hides of feedlot cattle. Cattle (n = 526) were divided among 16 feedlot pens. Half of the pens received the DFM, and the other half did not. Hide and fecal samples were collected from each animal on days 28, 63, and 84 of the feeding trial. Over the course of the 84-day feeding period, there were no significant differences observed between treatments for either hide or fecal prevalence of E. coli O157:H7, or for the percentage of animals that were shedding E. coli O157:H7 at high levels (> or =200 CFU/g) in their feces or harboring E. coli O157:H7 at high levels (> or =40 CFU/cm(2)) on their hides. In addition, there was no significant difference between the average daily gains for the treated and control groups, with both groups averaging 1.3 kg/day. We concluded that the DFM tested would not be an effective preharvest intervention against E. coli O157:H7.

Soluble arabinoxylan enhances large intestinal microbial health biomarkers in pigs fed a red meat-containing diet.

PubMed

Williams, Barbara A; Zhang, Dagong; Lisle, Allan T; Mikkelsen, Deirdre; McSweeney, Christopher S; Kang, Seungha; Bryden, Wayne L; Gidley, Michael J

2016-04-01

The aim of this study was to investigate how moderately increased dietary red meat combined with a soluble fiber (wheat arabinoxylan [AX]) alters the large intestinal microbiota in terms of fermentative end products and microbial community profiles in pigs. Four groups of 10 pigs were fed Western-type diets containing two amounts of red meat, with or without a solubilized wheat AX-rich fraction for 4 wk. After euthanasia, fermentative end products (short-chain fatty acids, ammonia) of digesta from four sections of large intestine were measured. Di-amino-pimelic acid was a measure of total microbial biomass, and bacterial profiles were determined using a phylogenetic microarray. A factorial model determined effects of AX and meat content. Arabinoxylan was highly fermentable in the cecum, as indicated by increased concentrations of short-chain fatty acids (particularly propionate). Protein fermentation end products were decreased, as indicated by the reduced ammonia and branched-chain ratio although this effect was less prominent distally. Microbial profiles in the distal large intestine differed in the presence of AX (including promotion of Faecalibacterium prausnitzii), consistent with an increase in carbohydrate versus protein fermentation. Increased di-amino-pimelic acid (P < 0.0001) suggested increased microbial biomass for animals fed AX. Solubilized wheat AX has the potential to counteract the effects of dietary red meat by reducing protein fermentation and its resultant toxic end products such as ammonia, as well as leading to a positive shift in fermentation end products and microbial profiles in the large intestine. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Formation of Short-Chain Fatty Acids, Excretion of Anthocyanins, and Microbial Diversity in Rats Fed Blackcurrants, Blackberries, and Raspberries

PubMed Central

Blanco, Narda; Ahrné, Siv; Molin, Göran

2013-01-01

Introduction. Berries contain high amounts of dietary fibre and flavonoids and have been associated with improved metabolic health. The mechanisms are not clear but the formation of SCFAs, especially propionic and butyric acids, could be important. The potent antioxidant and antimicrobial properties of flavonoids could also be a factor, but little is known about their fate in the gastrointestinal tract. Aim. To compare how blackcurrants, blackberries, raspberries, and Lactobacillus plantarum HEAL19 affect formation of SCFAs, inflammatory status, caecal microbial diversity, and flavonoids. Results and Conclusions. Degradation of the dietary fibre, formation of SCFAs including propionic and butyric acids, the weight of the caecal content and tissue, and the faecal wet and dry weight were all higher in rats fed blackcurrants rather than blackberries or raspberries. However, the microbial diversity of the gut microbiota was higher in rats fed raspberries. The high content of soluble fibre in blackcurrants and the high proportion of mannose-containing polymers might explain these effects. Anthocyanins could only be detected in urine of rats fed blackcurrants, and the excretion was lower with HEAL19. No anthocyanins or anthocyanidins were detected in caecal content or blood. This may indicate uptake in the stomach or small intestine. PMID:23864942

Screening of bacterial direct-fed microbials for their antimethanogenic potential in vitro and assessment of their effect on ruminal fermentation and microbial profiles in sheep.

PubMed

Jeyanathan, J; Martin, C; Morgavi, D P

2016-02-01

Direct-fed microbials (DFM) are used to modulate ruminal function and induce beneficial effects on ruminants. The objectives of this work were to 1) screen bacterial strains for their antimethanogenic potential in vitro and 2) assess the effect of 3 selected DFM on ruminal methane (CH) emissions, fermentation parameters, and microbial profiles in sheep. Forty-five bacterial strains were preselected based on their metabolism and fermentation characteristics. These bacteria were screened for their ability to reduce ruminal methanogenesis using 24-h batch incubations and an inoculum of 10 cfu/mL of medium. The addition of bacterial strains stimulated ruminal fermentation with increases in total gas production for 41 strains ( < 0.05) without a concomitant increase in CH production (only 9 strains had higher CH than the controls without DFM; < 0.05). 53-W, D31, and D1 had the greatest difference between total gas and CH production and were selected for further in vivo testing. Twelve rumen-cannulated Texel wethers were divided into 3 groups and were treated daily for 4 wk with 6 × 10 cfu/animal for and and 3 × 10 cfu/animal for . Measures of enteric CH, ruminal fermentation, and ruminal microbial traits were performed before, at 2 and 4 wk during the treatment period, and at 2 wk after the DFM treatment stopped. Methane production was reduced by 13% ( < 0.05) with after 2 wk of DFM administration, and this effect was maintained throughout the treatment and posttreatment periods. In contrast, had no effect on CH production, and increased it by 16% ( < 0.05) after 4 wk of DFM administration. There was no effect on other fermentation parameters or on the bacterial, archaeal, and protozoal numbers monitored by quantitative PCR. However, denaturing gradient gel electrophoresis profiles indicated changes in bacterial and archaeal diversity in the and groups. Although added bacteria were unable to permanently colonize the rumen, had a greater 24-h survival rate than the others, implying that the persistence of DFM may be important for modulating ruminal traits of interest. These results suggest that bacterial DFM used in this trial were able to modify CH emissions, although correlated changes in other ruminal parameters studied were minor.

Physiological and microbial adjustments to diet quality permit facultative herbivory in an omnivorous lizard.

PubMed

Kohl, Kevin D; Brun, Antonio; Magallanes, Melisa; Brinkerhoff, Joshua; Laspiur, Alejandro; Acosta, Juan Carlos; Bordenstein, Seth R; Caviedes-Vidal, Enrique

2016-06-15

While herbivory is a common feeding strategy in a number of vertebrate classes, less than 4% of squamate reptiles feed primarily on plant material. It has been hypothesized that physiological or microbial limitations may constrain the evolution of herbivory in lizards. Herbivorous lizards exhibit adaptations in digestive morphology and function that allow them to better assimilate plant material. However, it is unknown whether these traits are fixed or perhaps phenotypically flexible as a result of diet. Here, we maintained a naturally omnivorous lizard, Liolaemus ruibali, on a mixed diet of 50% insects and 50% plant material, or a plant-rich diet of 90% plant material. We compared parameters of digestive performance, gut morphology and function, and gut microbial community structure between the two groups. We found that lizards fed the plant-rich diet maintained nitrogen balance and exhibited low minimum nitrogen requirements. Additionally, lizards fed the plant-rich diet exhibited significantly longer small intestines and larger hindguts, demonstrating that gut morphology is phenotypically flexible. Lizards fed the plant-rich diet harbored small intestinal communities that were more diverse and enriched in Melainabacteria and Oscillospira compared with mixed diet-fed lizards. Additionally, the relative abundance of sulfate-reducing bacteria in the small intestine significantly correlated with whole-animal fiber digestibility. Thus, we suggest that physiological and microbial limitations do not sensu stricto constrain the evolution of herbivory in lizards. Rather, ecological context and fitness consequences may be more important in driving the evolution of this feeding strategy. © 2016. Published by The Company of Biologists Ltd.

Rumen microbial variation and nutrient utilisation in mithun (Bos frontalis) under different feeding regimes.

PubMed

Prakash, B; Saha, S K; Khate, K; Agarwal, N; Katole, S; Haque, N; Rajkhowa, C

2013-04-01

The aim of the study was to investigate the effect of feeding different diets on fermentation, enzyme activities and microbial population in the rumen fluid of mithun (Bos frontalis). In a randomized block design, 20 male mithun (6-8 months of age, 152 ± 12.6 kg body weight) were randomly divided into four experimental groups (n = 5/group) and fed experimental diets ad libitum for 180 days. The diet R1 contained tree foliages (TF), R2 comprised of 50% concentrate mixture (CM) and 50% TF, R3 contained 50% CM and 50% rice straw, and R4 contained 50% CM, 25% TF and 25% rice straw. Rumen liquor was collected at 0 and 180 days of the experiment for estimation of different ruminal parameters and a digestion trial was conducted at the end of the experiment. Rumen fluid was analysed for pH, ammonia nitrogen (NH3 -N), total-N, ruminal enzymes, short chain fatty acid (SCFA) and microbial profile. The relative quantification of ruminal microbes was carried out with real-time PCR using bacteria as the house keeping gene. The dry matter intake, nutrients digestibility, body weight gain, NH3 -N, total-N, carboxymethyl cellulase, avicelase, xylanase, amylase, protease and molar proportion of butyrate were (p < 0.05) higher in mithun fed R2 , R3 and R4 compared to those fed R1 diet. In contrast, increased (p < 0.05) ruminal pH, molar proportion of acetate and, acetate to propionate ratio was recorded in mithun fed only TF than those fed concentrate supplemented diets. Similarly, an increase (p < 0.05) in the population of Fibrobacter succinogenes, Ruminococcus flavefaciens and total bacteria were evident in mithun fed R2 , R3 and R4 compared to those fed R1 . Therefore, it is concluded that TF 25% and/or rice straw 25% along with CM 50% may be fed to the growing mithun for improved rumen ecology, nutrient utilization and thus better performance under stall fed system. © 2012 Blackwell Verlag GmbH.

Effect of a direct-fed microbial (Primalac) on structure and ultrastructure of small intestine in turkey poults.

PubMed

Rahimi, S; Grimes, J L; Fletcher, O; Oviedo, E; Sheldon, B W

2009-03-01

The effects of dietary supplementation of the direct-fed microbial (DFM) Primalac in mash or crumbled feed on histological and ultrastructural changes of intestinal mucosa was determined in 2 populations of poults; 1 with and 1 without a Salmonella spp. challenge. Three hundred thirty-six 1-d-old female Large White turkey poults were randomly distributed into 8 treatment groups with 6 replicates of 7 poults in each pen. The poults were placed on 1 of 4 dietary treatments in a 2 x 2 x 2 factorial arrangement (mash or crumble feed, with or without DFM, not-challenged or challenged at 3 d of age). The DFM groups were fed a Primalac-supplemented diet from d 1 until the last day of the experiment (d 21). At 3 d of age, 50% of the poults were challenged with 1 mL of 10(10) cfu/ mL of Salmonella spp. (Salmonella enterica serovar Typhimurium, Salmonella Heidelberg, and Salmonella Kentucky) by oral gavage. The inoculated poults were housed in a separate room from nonchallenged controls. Feed and water were provided ad libitum for all birds. At d 21, 1 poult per pen (total of 6 poults per treatment) was randomly selected and killed humanely by cervical dislocation. After necropsy, the small intestine was removed, and tissue samples from duodenum, jejunum, and ileum were taken for light and electron microscopic evaluation. The DFM birds showed increased goblet cell (GC) numbers, total GC area, GC mean size, mucosal thickness, and a greater number of segmented filamentous bacteria compared with controls. Changes in intestinal morphology as observed in this study support the concept that poultry gut health and function, and ultimately bird performance, can be improved by dietary supplementation with DFM products such as Primalac as used in this study.

A novel process-based model of microbial growth: self-inhibition in Saccharomyces cerevisiae aerobic fed-batch cultures.

PubMed

Mazzoleni, Stefano; Landi, Carmine; Cartenì, Fabrizio; de Alteriis, Elisabetta; Giannino, Francesco; Paciello, Lucia; Parascandola, Palma

2015-07-30

Microbial population dynamics in bioreactors depend on both nutrients availability and changes in the growth environment. Research is still ongoing on the optimization of bioreactor yields focusing on the increase of the maximum achievable cell density. A new process-based model is proposed to describe the aerobic growth of Saccharomyces cerevisiae cultured on glucose as carbon and energy source. The model considers the main metabolic routes of glucose assimilation (fermentation to ethanol and respiration) and the occurrence of inhibition due to the accumulation of both ethanol and other self-produced toxic compounds in the medium. Model simulations reproduced data from classic and new experiments of yeast growth in batch and fed-batch cultures. Model and experimental results showed that the growth decline observed in prolonged fed-batch cultures had to be ascribed to self-produced inhibitory compounds other than ethanol. The presented results clarify the dynamics of microbial growth under different feeding conditions and highlight the relevance of the negative feedback by self-produced inhibitory compounds on the maximum cell densities achieved in a bioreactor.

Protective Effects of Ellagitannin-Rich Strawberry Extracts on Biochemical and Metabolic Disturbances in Rats Fed a Diet High in Fructose.

PubMed

Fotschki, Bartosz; Juśkiewicz, Jerzy; Kołodziejczyk, Krzysztof; Jurgoński, Adam; Kosmala, Monika; Milala, Joanna; Ognik, Katarzyna; Zduńczyk, Zenon

2018-04-04

The present study compares the effects of two dietary strawberry extracts rich in monomeric (ME) or dimeric (DE) ellagitannins (ETs) on gastrointestinal, blood and tissue biomarkers in Wistar rats fed high-fructose diets. Both strawberry extracts beneficially affect the antioxidant status and lipid profile of the liver and serum. The ME extract shows a greater ability to inhibit lipid peroxidation in kidneys, more effectively decreases serum and liver triglycerides, and exerts greater anti-inflammatory effects in blood serum than the DE extract. The DE extract significantly reduces the activity of microbial enzymes in the cecum. These effects might be associated with higher cecum and urine levels of ET metabolites in rats fed with ME than in rats fed with DE. In conclusion, the diet-induced fructose-related disturbances observed in biochemical parameters are regulated by both extracts; nevertheless, the beneficial effects of the ME extract are mostly associated with systemic parameters, while those of the DE extracts are associated with local microbial activity.

The Fecal Microbial Community of Breast-fed Infants from Armenia and Georgia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Zachery T.; Sidamonidze, Ketevan; Tsaturyan, Vardan

Multiple factors help shape the infant intestinal microbiota early in life. Environmental conditions such as the presence of bioactive molecules from breast milk dictate gut microbial growth and survival. Infants also receive distinct, personalized, bacterial exposures leading to differential colonization. Microbial exposures and gut environmental conditions differ between infants in different locations, as does the typical microbial community structure in an infant’s gut. Here we evaluate potential influences on the infant gut microbiota through a longitudinal study on cohorts of breast-fed infants from the neighboring countries of Armenia and Georgia, an area of the world for which the infant microbiomemore » has not been previously investigated. Marker gene sequencing of 16S ribosomal genes revealed that the gut microbial communities of infants from these countries were dominated by bifidobacteria, were different from each other, and were marginally influenced by their mother’s secretor status. Species-level differences in the bifidobacterial communities of each country and birth method were also observed. These community differences suggest that environmental variation between individuals in different locations may influence the gut microbiota of infants.« less

The Fecal Microbial Community of Breast-fed Infants from Armenia and Georgia

PubMed Central

Lewis, Zachery T; Sidamonidze, Ketevan; Tsaturyan, Vardan; Tsereteli, David; Khachidze, Nika; Pepoyan, Astghik; Zhgenti, Ekaterine; Tevzadze, Liana; Manvelyan, Anahit; Balayan, Marine; Imnadze, Paata; Torok, Tamas; Lemay, Danielle G.; Mills, David A.

2017-01-01

Multiple factors help shape the infant intestinal microbiota early in life. Environmental conditions such as the presence of bioactive molecules from breast milk dictate gut microbial growth and survival. Infants also receive distinct, personalized, bacterial exposures leading to differential colonization. Microbial exposures and gut environmental conditions differ between infants in different locations, as does the typical microbial community structure in an infant’s gut. Here we evaluate potential influences on the infant gut microbiota through a longitudinal study on cohorts of breast-fed infants from the neighboring countries of Armenia and Georgia, an area of the world for which the infant microbiome has not been previously investigated. Marker gene sequencing of 16S ribosomal genes revealed that the gut microbial communities of infants from these countries were dominated by bifidobacteria, were different from each other, and were marginally influenced by their mother’s secretor status. Species-level differences in the bifidobacterial communities of each country and birth method were also observed. These community differences suggest that environmental variation between individuals in different locations may influence the gut microbiota of infants. PMID:28150690

The Fecal Microbial Community of Breast-fed Infants from Armenia and Georgia

DOE PAGES

Lewis, Zachery T.; Sidamonidze, Ketevan; Tsaturyan, Vardan; ...

2017-02-02

Multiple factors help shape the infant intestinal microbiota early in life. Environmental conditions such as the presence of bioactive molecules from breast milk dictate gut microbial growth and survival. Infants also receive distinct, personalized, bacterial exposures leading to differential colonization. Microbial exposures and gut environmental conditions differ between infants in different locations, as does the typical microbial community structure in an infant’s gut. Here we evaluate potential influences on the infant gut microbiota through a longitudinal study on cohorts of breast-fed infants from the neighboring countries of Armenia and Georgia, an area of the world for which the infant microbiomemore » has not been previously investigated. Marker gene sequencing of 16S ribosomal genes revealed that the gut microbial communities of infants from these countries were dominated by bifidobacteria, were different from each other, and were marginally influenced by their mother’s secretor status. Species-level differences in the bifidobacterial communities of each country and birth method were also observed. These community differences suggest that environmental variation between individuals in different locations may influence the gut microbiota of infants.« less

A comparison of bioelectricity in microbial fuel cells with aerobic and anaerobic anodes.

PubMed

Chen, Chih-Yu; Chen, Tzu-Yu; Chung, Ying-Chien

2014-01-01

Microbial fuel cells (MFCs) can, besides running on wastewater, also derive energy directly from certain aquatic plants. However, few studies have focussed on electricity generation using aerobic anodes. This study presents a comparison of the MFC performances of an anaerobic-anode MFC (ana-MFC) and an aerobic-anode MFC (aa-MFC), and shows their individual conditions for optimal operation. Results show that the maximum power density of 7.07 +/- 0.45 mW/m2 for the ana-MFC occurred at 500 omega, whereas the aa-MFC had a maximum power density of 2.34 +/- 0.16 mW/m2 at 2200 omega. The ana-MFC generally achieved high electricity generation, and the aa-MFC achieved relatively high electricity generation when fed with a diluted substrate. In the ana-MFC, the optimal substrate for electricity generation was glucose (fermentable substrate); however, glucose and acetic acid (non-fermentable substrate) were both suitable substrates for the aa-MFC. The optimal gas retention times of the ana-MFC and the aa-MFC were 9 and 120 s, respectively. This retention time is an important limiting factor of electricity generation for the ana-MFC. The aa-MFCs fed with different substrates exhibited non-significant differences between bacterial communities. We observed the relative diversities of bacterial communities in the ana-MFC fed with various substrates. The results of denaturing gradient gel electrophoresis analysis suggest that Ochrobactrum intermedium, Delftia acidovorans, and Citrobacterfreundii may be potential electrogenic bacteria. To our knowledge, this is the first study comparing the MFC performances of anaerobic and aerobic anodes.

Host-Microbe Interactions in the Neonatal Intestine: Role of Human Milk Oligosaccharides123

PubMed Central

Donovan, Sharon M.; Wang, Mei; Li, Min; Friedberg, Iddo; Schwartz, Scott L.; Chapkin, Robert S.

2012-01-01

The infant intestinal microbiota is shaped by genetics and environment, including the route of delivery and early dietary intake. Data from germ-free rodents and piglets support a critical role for the microbiota in regulating gastrointestinal and immune development. Human milk oligosaccharides (HMO) both directly and indirectly influence intestinal development by regulating cell proliferation, acting as prebiotics for beneficial bacteria and modulating immune development. We have shown that the gut microbiota, the microbial metatranscriptome, and metabolome differ between porcine milk–fed and formula-fed (FF) piglets. Our goal is to define how early nutrition, specifically HMO, shapes host-microbe interactions in breast-fed (BF) and FF human infants. We an established noninvasive method that uses stool samples containing intact sloughed epithelial cells to quantify intestinal gene expression profiles in human infants. We hypothesized that a systems biology approach, combining i) HMO composition of the mother’s milk with the infant’s gut gene expression and fecal bacterial composition, ii) gene expression, and iii short-chain fatty acid profiles would identify important mechanistic pathways affecting intestinal development of BF and FF infants in the first few months of life. HMO composition was analyzed by HLPC Chip/time-of-flight MS and 3 HMO clusters were identified using principle component analysis. Initial findings indicated that both host epithelial cell mRNA expression and the microbial phylogenetic profiles provided strong feature sets that distinctly classified the BF and FF infants. Ongoing analyses are designed to integrate the host transcriptome, bacterial phylogenetic profiles, and functional metagenomic data using multivariate statistical analyses. PMID:22585924

Microbial Incorporation of Fatty Acids Derived From n-Alkanes Into Glycerides and Waxes

PubMed Central

Davis, J. B.

1964-01-01

When n-alkanes with 13 to 20 carbon atoms were fed to a Nocardia closely related to N. salmonicolor, the produced cellular triglycerides and aliphatic waxes invariably contained fatty acids with an even or an odd number of carbon atoms subject to this feature of the n-alkane substrate. Beta-oxidation and C2 addition are both operative, as evidenced by the spectra of fatty acids incorporated into the cellular lipid components. There is no distinction in the rate of microbial incorporation of the odd-or even-numbered carbon chains. The fatty acids are apparently directly derived from the long chain n-alkanes, rather than synthesized via the classic C2-condensation route. The alcohol component of waxes produced by the Nocardia is invariably of the same chain length as the n-alkane substrate. PMID:14170957

Electron acceptors for energy generation in microbial fuel cells fed with wastewaters: A mini-review.

PubMed

He, Chuan-Shu; Mu, Zhe-Xuan; Yang, Hou-Yun; Wang, Ya-Zhou; Mu, Yang; Yu, Han-Qing

2015-12-01

Microbial fuel cells (MFCs) have gained tremendous global interest over the last decades as a device that uses bacteria to oxidize organic and inorganic matters in the anode with bioelectricity generation and even for purpose of bioremediation. However, this prospective technology has not yet been carried out in field in particular because of its low power yields and target compounds removal which can be largely influenced by electron acceptors contributing to overcome the potential losses existing on the cathode. This mini review summarizes various electron acceptors used in recent years in the categories of inorganic and organic compounds, identifies their merits and drawbacks, and compares their influences on performance of MFCs, as well as briefly discusses possible future research directions particularly from cathode aspect. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fed-batch anaerobic valorization of slaughterhouse by-products with mesophilic microbial consortia without methane production.

PubMed

Pessiot, J; Nouaille, R; Jobard, M; Singhania, R R; Bournilhas, A; Christophe, G; Fontanille, P; Peyret, P; Fonty, G; Larroche, C

2012-07-01

This work aimed at setting up a fully instrumented, laboratory-scale bioreactor enabling anaerobic valorization of solid substrates through hydrogen and/or volatile fatty acid (VFA) production using mixed microbial populations (consortia). The substrate used was made of meat-based wastes, especially from slaughterhouses, which are becoming available in large amounts as a consequence of the growing constraints for waste disposal from meat industry. A reconstituted microbial mesophilic consortium without Archaebacteria (methanogens), named PBr, was cultivated in a 5-L anaerobic bioreactor on slaughterhouse wastes. The experiments were carried out with sequential fed-batch operations, including liquid medium removal from the bioreactor and addition of fresh substrate. VFAs and nitrogen were the main metabolites observed, while hydrogen accumulation was very low and no methane production was evidenced. After 1,300 h of culture, yields obtained for VFAs reached 0.38 g/g dry matter. Strain composition of the microbial consortium was also characterized using molecular tools (temporal temperature gradient gel electrophoresis and gene sequencing).

Performance and ruminal changes of early-weaned calves fed lasalocid.

PubMed

Anderson, K L; Nagaraja, T G; Morrill, J L; Reddy, P G; Avery, T B; Anderson, N V

1988-03-01

Twenty-two neonatal calves were assigned to a control or lasalocid-fed group and weaned at 3 wk of age. They were fed a prestarter diet from 3 d of age until they consumed 227 g/d and then a mixture of 227 g prestarter daily and starter diet in ad libitum amounts. The lasalocid-fed group received lasalocid in milk at 1 mg/kg body weight daily from 4 to 7 d and at .5 mg/kg body weight daily in milk and medicated prestarter diet (88 mg lasalocid/kg) during the 2nd wk. After 2 wk, lasalocid-fed calves were given medicated prestarter and starter (44 mg lasalocid/kg) diets. Four calves in each group were ruminally cannulated at 3 to 5 d of age, and ruminal contents were obtained at weekly intervals to monitor microbial activity. Rectal fecal samples were collected from all calves and examined for coccidial oocysts. Lasalocid-fed calves had a greater weekly feed intake and weight gain than control calves after 6 wk of age. Total ruminal volatile fatty acid concentrations were higher, but the acetate:propionate ratio was lower in lasalocid-fed calves than in control calves. Total viable anaerobic and amylolytic bacterial counts were higher in lasalocid-fed calves than in control calves. No significant treatment effect was found for ruminal NH3-N concentration or ruminal lasalocid-resistant, lactobacilli, lactate-utilizing, cellulolytic or methanogenic bacterial numbers. No evidence of coccidiosis was detected in either group. In general, lasalocid-fed calves had greater feed intake, weight gain and ruminal microbial activity than the calves fed no lasalocid in the diet.

Effects of feeding corn silage inoculated with microbial additives on the ruminal fermentation, microbial protein yield, and growth performance of lambs.

PubMed

Basso, F C; Adesogan, A T; Lara, E C; Rabelo, C H S; Berchielli, T T; Teixeira, I A M A; Siqueira, G R; Reis, R A

2014-12-01

This study aimed to examine the effects of feeding corn silage inoculated without or with either Lactobacillus buchneri (LB) alone or a combination of LB and Lactobacillus plantarum (LBLP) on the apparent digestibility, ruminal fermentation, microbial protein synthesis, and growth performance of lambs. Thirty Santa Inês×Dorper crossbred intact males lambs weighing 20.4±3.8 kg were blocked by weight into 10 groups. Lambs in each group were randomly assigned to 1 of the following 3 dietary treatments: untreated (Control), LB, and LBLP silage. Lambs were fed experimental diets for 61 d. The apparent digestibility was indirectly estimated from indigestible NDF measured on d 57 to 59. Spot urine samples were collected from all animals on d 59 to estimate microbial protein synthesis. Lambs were slaughtered for carcass evaluation on d 61 when they weighed 32.4±5.2 kg. Six additional ruminally cannulated Santa Inês×Dorper crossbred wethers weighing 40.5±1.8 kg were used to examine dietary effects on ruminal fermentation. Average daily gain was increased when lambs were fed LBLP silage (P<0.05) but not LB silage. The LBLP silage had the highest (P<0.05) lactic acid concentration and both inoculated silages had greater acetic acid concentrations than the Control silage (P<0.05). Inoculation of corn silage increased intakes of DM, OM, CP, NDF, total carbohydrate (CHO), and GE by the lambs but decreased digestibility of DM, OM, CP, total and nonstructural carbohydrates, and concentration of GE and ME. (P<0.05). Nevertheless, lambs fed inoculated silages had greater microbial N supply than those on the Control treatment (P<0.05). The acetate to propionate ratio was lower in ruminal fluid of wethers in LBLP treatment than LB and Control treatment (P<0.05) and ruminal pH tended to be greater in LB lambs than in LBLP and Control wethers (P<0.10). Finally, the inoculation with both bacteria combined enhanced the silage fermentation. The intakes of DM, OM, CP, NDF, and GE were improved in the lambs fed corn silage inoculated with L. buchneri alone or combined with L. plantarum. The microbial N supply was enhanced in the lambs fed corn silage inoculated with L. buchneri. The inoculation of L. buchneri combined with L. plantarum reduced the acetate to propionate ratio in ruminal fluid and improved the ADG of lambs.

Aerated Shewanella oneidensis in Continuously-fed Bioelectrochemical Systems for Power and Hydrogen Production

USDA-ARS?s Scientific Manuscript database

We studied the effects of aeration of Shewanella oneidensis on potentiostatic current production, iron(III) reduction, hydrogen production in a microbial electrolysis cell, and electric power generation in a microbial fuel cell. The potentiostatic performance of aerated S. oneidensis was considerab...

Temporal Microbial Community Dynamics in Microbial Electrolysis Cells – Influence of Acetate and Propionate Concentration

PubMed Central

Hari, Ananda Rao; Venkidusamy, Krishnaveni; Katuri, Krishna P.; Bagchi, Samik; Saikaly, Pascal E.

2017-01-01

Microbial electrolysis cells (MECs) are widely considered as a next generation wastewater treatment system. However, fundamental insight on the temporal dynamics of microbial communities associated with MEC performance under different organic types with varied loading concentrations is still unknown, nevertheless this knowledge is essential for optimizing this technology for real-scale applications. Here, the temporal dynamics of anodic microbial communities associated with MEC performance was examined at low (0.5 g COD/L) and high (4 g COD/L) concentrations of acetate or propionate, which are important intermediates of fermentation of municipal wastewaters and sludge. The results showed that acetate-fed reactors exhibited higher performance in terms of maximum current density (I: 4.25 ± 0.23 A/m2), coulombic efficiency (CE: 95 ± 8%), and substrate degradation rate (98.8 ± 1.2%) than propionate-fed reactors (I: 2.7 ± 0.28 A/m2; CE: 68 ± 9.5%; substrate degradation rate: 84 ± 13%) irrespective of the concentrations tested. Despite of the repeated sampling of the anodic biofilm over time, the high-concentration reactors demonstrated lower and stable performance in terms of current density (I: 1.1 ± 0.14 to 4.2 ± 0.21 A/m2), coulombic efficiency (CE: 44 ± 4.1 to 103 ± 7.2%) and substrate degradation rate (64.9 ± 6.3 to 99.7 ± 0.5%), while the low-concentration reactors produced higher and dynamic performance (I: 1.1 ± 0.12 to 4.6 ± 0.1 A/m2; CE: 52 ± 2.5 to 105 ± 2.7%; substrate degradation rate: 87.2 ± 0.2 to 99.9 ± 0.06%) with the different substrates tested. Correlating reactor’s performance with temporal dynamics of microbial communities showed that relatively similar anodic microbial community composition but with varying relative abundances was observed in all the reactors despite differences in the substrate and concentrations tested. Particularly, Geobacter was the predominant bacteria on the anode biofilm of all MECs over time suggesting its possible role in maintaining functional stability of MECs fed with low and high concentrations of acetate and propionate. Taken together, these results provide new insights on the microbial community dynamics and its correlation to performance in MECs fed with different concentrations of acetate and propionate, which are important volatile fatty acids in wastewater. PMID:28775719

Suitable strategy to improve nitrogen utilization and reduce the environmental impact of Nellore bulls supplemented on tropical pasture.

PubMed

Jose Neto, A; Zervoudakis, J T; da Silva-Marques, R P; Silva, L C R P; Hatamoto-Zervoudakis, L K; Klopfenstein, T J

2016-03-01

Expansion of the biodiesel industry has increased the crude glycerin (CG) supply. Crude glycerin has the potential of replacing corn in ruminant diets because the glycerol can be converted to glucose in the liver of ruminants, providing energy for cellular metabolism. The objective was to evaluate the effects of CG with urea, soybean meal, cottonseed meal, and corn gluten feed, respectively, on intake, digestibility, microbial protein yield, and efficiency of N utilization. Five Nellore bulls (initial BW of 448 kg [SD 14]) grazing tropical pasture were used in a 5 × 5 Latin square design. The supplements were control (no supplementation; only free-choice mineral mixture ad libitum), CG with urea (CG-Urea), CG with soybean meal, CG with cottonseed meal, and CG with corn gluten. Crude glycerin was used in all supplements to replace corn (15% of DM supplement). There were differences between CG-Urea and other supplements with regard to intake of DM (% of BW and total; < 0.01), OM ( < 0.01), CP ( < 0.01), and TDN ( < 0.01). The digestibility of CP was greater ( = 0.04) for animals supplemented with CG-Urea than for those fed other supplements. Animals supplemented with CG-Urea showed greater N intake ( < 0.01) and N ammonia ( = 0.04) than those supplemented with other treatments. Nitrogen retained (g/d) was not affected by protein source but was greater for cattle fed a protein supplement compared with cattle fed the control supplement ( < 0.01). Supplementing the animals with protein sources increased ( = 0.02) the daily production of rumen microbial nitrogen (g/d) compared with the control group. Microbial protein (g/d) was lesser for the control than for protein sources ( = 0.02). However, when expressed relative to TDN ( = 0.35) and CP ( = 0.82), there were no differences across treatments. Crude protein intake per digestible OM intake (g CP/kg digestible OM intake) was greater for animals fed protein sources compared with animals fed control supplements ( < 0.01). Based on nutrients intake and microbial protein yield, CG-Urea supplement has a greater feeding value compared with other protein sources. Crude glycerin, when used to replace corn in 15% of DM supplement, may be effective to improved N utilization and microbial protein yield in rumen of Nellore bulls grazing cv. Marandu.

Effect of fed-batch vs. continuous mode of operation on microbial fuel cell performance treating biorefinery wastewater

DOE PAGES

Pannell, Tyler C.; Goud, R. Kannaiah; Schell, Daniel J.; ...

2016-05-01

Bioelectrochemical systems have been shown to treat low-value biorefinery streams while recovering energy, however, low current densities and anode conversion efficiencies (ACE) limit their application. A bioanode was developed via enrichment of electroactive biofilm under fed-batch and continuous feeding conditions using corn stover-derived waste stream. The continuously-fed MFC exhibited a current density of 5.8±0.06 A/m 2 and an ACE of 39%±4. The fed-batch MFC achieved a similar current density and an ACE of 19.2%, however, its performance dropped after 36 days of operation to 1.1 A/m 2 and 0.5%, respectively. In comparison, the ACE of the continuously-fed MFC remained stablemore » achieving an ACE of 30% ± 3 after 48 days of operation. An MFC treating a biorefinery stream post fuel separation achieved a current density of 10.7±0.1 A/m 2 and an ACE of 57% ± 9 at an organic loading of 12.5 g COD/L-day. Characterization of the microbial communities indicate higher abundance of Firmicutes and Proteobacteria and lower abundance of Bacteriodetes and a higher level of Geobacter spp. (1.4% vs. 0.2%) in continuously-fed MFC vs. fed-batch MFC. Finally, the results demonstrate that limiting substrate to the equivalent maximum current that the anode can generate, maintains MFC performance over a long term for high strength wastewaters, such as those generated in the biorefinery.« less

Effect of fed-batch vs. continuous mode of operation on microbial fuel cell performance treating biorefinery wastewater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pannell, Tyler C.; Goud, R. Kannaiah; Schell, Daniel J.

Bioelectrochemical systems have been shown to treat low-value biorefinery streams while recovering energy, however, low current densities and anode conversion efficiencies (ACE) limit their application. A bioanode was developed via enrichment of electroactive biofilm under fed-batch and continuous feeding conditions using corn stover-derived waste stream. The continuously-fed MFC exhibited a current density of 5.8±0.06 A/m 2 and an ACE of 39%±4. The fed-batch MFC achieved a similar current density and an ACE of 19.2%, however, its performance dropped after 36 days of operation to 1.1 A/m 2 and 0.5%, respectively. In comparison, the ACE of the continuously-fed MFC remained stablemore » achieving an ACE of 30% ± 3 after 48 days of operation. An MFC treating a biorefinery stream post fuel separation achieved a current density of 10.7±0.1 A/m 2 and an ACE of 57% ± 9 at an organic loading of 12.5 g COD/L-day. Characterization of the microbial communities indicate higher abundance of Firmicutes and Proteobacteria and lower abundance of Bacteriodetes and a higher level of Geobacter spp. (1.4% vs. 0.2%) in continuously-fed MFC vs. fed-batch MFC. Finally, the results demonstrate that limiting substrate to the equivalent maximum current that the anode can generate, maintains MFC performance over a long term for high strength wastewaters, such as those generated in the biorefinery.« less

Cecum microbial communities from steers differing in feed efficiency

USDA-ARS?s Scientific Manuscript database

Aims: To characterize the microbial communities of the cecum among steers differing in feed efficiency. Methods and Results: Individual feed intake (FI) and body weight (BW) gain were determined from animals fed the same ration, within two contemporary groups of steers. BW gain was regressed on F...

Efficacy of a vaccine and a direct-fed microbial against fecal shedding of Escherichia coli O157:H7 in a randomized pen-level field trial of commercial feedlot cattle.

PubMed

Cull, Charley A; Paddock, Zachary D; Nagaraja, T G; Bello, Nora M; Babcock, Abram H; Renter, David G

2012-09-21

Our primary objective was to determine the efficacy of a siderophore receptor and porin proteins-based vaccine (VAC) and a Lactobacillus acidophilus-based direct-fed microbial (DFM) against fecal shedding of Escherichia coli O157:H7 in commercial feedlot cattle fed a corn grain-based diet with 25% distiller's grains. Cattle projected to be on a finishing diet during the summer were randomly allocated into 40 study pens within ten blocks based on allocation dates. Blocks were complete; each of the four pens within a block was randomly assigned one treatment: control, VAC, DFM, or VAC+DFM. The DFM was fed (10⁶CFU/animal/day of Lactobacillus) throughout the study periods (84-88 days) and cattle were vaccinated at enrollment and again three weeks later. Fresh fecal samples (30/pen) from pen floors were collected weekly for four consecutive weeks (study days 52-77). Two concurrent culture procedures were used to enable estimates of E. coli O157:H7 shedding prevalence and prevalence of high shedders. From 4800 total samples, 1522 (31.7%) were positive for E. coli O157:H7 and 169 (3.5%) were considered high shedders. Pen-level linear mixed models were used for data analyses. There were no significant interactions among treatments and time of sampling. However, vaccinated pens had lower (P<0.01) overall prevalence of E. coli O157:H7 (model-adjusted mean ± SEM=17.4 ± 3.95%) and lower (P<0.01) prevalence of high shedders (0.95 ± 0.26%) than unvaccinated pens (37.0 ± 6.32% and 4.19 ± 0.81%, respectively). There was no evidence of a DFM effect on either measure of E. coli O157:H7 shedding. Results indicate that a two-dose regimen of the vaccine significantly reduces fecal prevalence of E. coli O157:H7 (vaccine efficacy of 53.0%) and prevalence of E. coli O157:H7 high shedders (vaccine efficacy of 77.3%) in commercial feedlot cattle reared in the summer on a finishing diet with 25% distiller's grains. Copyright © 2012 Elsevier Ltd. All rights reserved.

Brewery and liquid manure wastewaters as potential feedstocks for microbial fuel cells: a performance study.

PubMed

Angosto, J M; Fernández-López, J A; Godínez, C

2015-01-01

This work aims at the comparison of the electrical and chemical performance of microbial fuel cells (MFCs) fed with several types of brewery and manure industrial wastewaters. Experiments were conducted in a single-cell MFC with the cathode exposed to air operated in batch and fed-batch modes. In fed-batch mode, after 4 days of operation, a standard MFC was refilled with crude wastewater to regenerate the biofilm and recreate initial feeding conditions. Brewery wastewater (CV1) mixed with pig-farm liquid manure (PU sample) gave the highest voltage (199.8 mV) and power density (340 mW/m3) outputs than non-mixed brewery waste water. Also, coulombic efficiency is much larger in the mixture (11%) than in the others (2-3%). However, in terms of chemical oxygen demand removal, the performance showed to be poorer (53%) for the mixed sample than in the pure brewery sample (93%). Fed-batch operation showed to be a good alternate for quasi-continuous operation, with equivalent electrical and chemical yields as compared with normal batchwise operation.

Dietary microbial phytase exerts mixed effects on the gut health of tilapia: a possible reason for the null effect on growth promotion.

PubMed

Hu, Jun; Ran, Chao; He, Suxu; Cao, Yanan; Yao, Bin; Ye, Yuantu; Zhang, Xuezhen; Zhou, Zhigang

2016-06-01

The present study evaluated the effects of dietary microbial phytase on the growth and gut health of hybrid tilapia (Oreochromis niloticus ♀×Oreochromis aureus ♂), focusing on the effect on intestinal histology, adhesive microbiota and expression of immune-related cytokine genes. Tilapia were fed either control diet or diet supplemented with microbial phytase (1000 U/kg). Each diet was randomly assigned to four groups of fish reared in cages (3×3×2 m). After 12 weeks of feeding, weight gain and feed conversion ratio of tilapia were not significantly improved by dietary microbial phytase supplementation. However, significantly higher level of P content in the scales, tighter and more regular intestinal mucosa folds were observed in the microbial phytase group and the microvilli density was significantly increased. The adhesive gut bacterial communities were strikingly altered by microbial phytase supplementation (0·41

Effect of sulfur supplements on cellulolytic rumen micro-organisms and microbial protein synthesis in cattle fed a high fibre diet.

PubMed

McSweeney, C S; Denman, S E

2007-11-01

To examine the effect of sulfur-containing compounds on the growth of anaerobic rumen fungi and the fibrolytic rumen bacteria Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes in pure culture and within the cattle rumen. The effect of two reduced sulfur compounds, 3-mercaptopropionic acid (MPA) or 3-mercapto-1-propanesulfonic acid as the sole S source on growth of pure fibroyltic fungal and bacterial cultures showed that these compounds were capable of sustaining growth. An in vivo trial was then conducted to determine the effect of sulfur supplements (MPA and sodium sulfate) on microbial population dynamics in cattle fed the roughage Dichanthium aristatum. Real-time PCR showed significant increases in fibrolytic bacterial and fungal populations when cattle were supplemented with these compounds. Sulfate supplementation leads to an increase in dry matter intake without a change in whole tract dry matter digestibility. Supplementation of low S-containing diets with either sodium sulfate or MPA stimulates microbial growth with an increase in rumen microbial protein supply to the animal. Through the use of real-time PCR monitoring, a better understanding of the effect of S supplementation on discrete microbial populations within the rumen is provided.

Dynamics of microbial communities in untreated and autoclaved food waste anaerobic digesters.

PubMed

Blasco, Lucia; Kahala, Minna; Tampio, Elina; Ervasti, Satu; Paavola, Teija; Rintala, Jukka; Joutsjoki, Vesa

2014-10-01

This study describes the microbial community richness and dynamics of two semi-continuously stirred biogas reactors during a time-course study of 120 days. The reactors were fed with untreated and autoclaved (160 °C, 6.2 bar) food waste. The microbial community was analysed using a bacteria- and archaea-targeting 16S rRNA gene-based Terminal-Restriction Fragment Length Polymorphism (T-RFLP) approach. Compared with the archaeal community, the structures and functions of the bacterial community were found to be more complex and diverse. With the principal coordinates analysis it was possible to separate both microbial communities with 75 and 50% difference for bacteria and archaea, respectively, in the two reactors fed with the same waste but with different pretreatment. Despite the use of the same feeding material, anaerobic reactors showed a distinct community profile which could explain the differences in methane yield (2-17%). The community composition was highly dynamic for bacteria and archaea during the entire studied period. This study illustrates that microbial communities are dependent on feeding material and that correlations among specific bacterial and archaeal T-RFs can be established. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Replacing Soybean Meal by Raw or Extruded Pea Seeds on Growth Performance and Selected Physiological Parameters of the Ileum and Distal Colon of Pigs

PubMed Central

Taciak, Marcin; Barszcz, Marcin; Święch, Ewa; Bachanek, Ilona; Skomiał, Jacek

2017-01-01

The use of pea seeds is limited due to the content of antinutritional factors that may affect gut physiology. Heat treatment such as extrusion may reduce heat-labile antinutritional factors and improve the nutritional value of pea seeds. This study determined the effect of partial replacement of soybean meal in pig diets by raw or extruded pea seeds on growth performance, nitrogen balance and physiology of the ileum and distal colon. The experiment was carried out in 18 castrated male piglets of initial body weight of 11 kg, divided into three groups. The animals were fed cereal-based diets with soybean meal (C), which was partly replaced by raw (PR) or extruded pea (PE) seeds. Nitrogen balance was measured at about 15 kg body weight. After 26 days of feeding, tissue samples were taken from the ileum and distal colon for histological measurements, and colonic digesta samples for analyses of microbial activity indices. The animals fed the PE diet had a significantly greater average daily gain than those fed the C diet and better apparent protein digestibility than those on the PR diet. Pigs fed the PR diet had a significantly greater butyric acid concentration and lower pH in the colon than pigs fed PE and C diets. There was no significant effect of the diet on other indices of microbial activity or morphological parameters. In conclusion, feeding a diet with extruded pea seeds improved growth performance of pigs, did not affect intestinal morphology and had a negligible effect on microbial activity in the distal colon. PMID:28060879

Performance and membrane fouling of a step-fed submerged membrane sequencing batch reactor treating swine biogas digestion slurry.

PubMed

Han, Zhiying; Chen, Shixia; Lin, Xiaochang; Yu, Hongjun; Duan, Li'an; Ye, Zhangying; Jia, Yanbo; Zhu, Songming; Liu, Dezhao

2018-01-02

To identify the performance of step-fed submerged membrane sequencing batch reactor (SMSBR) treating swine biogas digestion slurry and to explore the correlation between microbial metabolites and membrane fouling within this novel reactor, a lab-scale step-fed SMSBR was operated under nitrogen loading rate of 0.026, 0.052 and 0.062 g NH 4 + -N (gVSS·d) -1 . Results show that the total removal efficiencies for NH 4 + -N, total nitrogen and chemical oxygen demand in the reactor (>94%, >89% and >97%, respectively) were high during the whole experiment. However, the cycle removal efficiency of NH 4 + -N decreased significantly when the nitrogen loading rate was increased to 0.062 g NH 4 + -N (gVSS·d) -1 . The total removal efficiency of total phosphorus in the step-fed SMSBR was generally higher than 75%, though large fluctuations were observed during the experiments. In addition, the concentrations of microbial metabolites, i.e., soluble microbial products (SMP) and extracellular polymeric substances (EPS) from activated sludge increased as nitrogen loading rate increased, both showing quadratic equation correlations with viscosity of the mixed liquid in the step-fed SMSBR (both R 2 > 0.90). EPS content was higher than SMP content, while protein (PN) was detected as the main component in both SMP and EPS. EPS PN was found to be well correlated with transmembrane pressure, membrane flux and the total membrane fouling resistance. Furthermore, the three-dimensional excitation-emission matrix fluorescence spectroscopy results suggested the tryptophan-like protein as one of the main contributors to the membrane fouling. Overall, this study showed that the step-fed SMSBR could be used to treat swine digestion slurry at nitrogen loading rate of 0.052 g NH 4 + -N (gVSS·d) -1 , and the control strategy of membrane fouling should be developed based on reducing the tryptophan-like PN in EPS.

The Urban Watershed as a Transformer of DOM Chemistry

NASA Astrophysics Data System (ADS)

Gabor, R. S.; Smith, R. M.; Follstad Shah, J.; Kelso, J. E.; Baker, M. A.; Brooks, P. D.

2017-12-01

Growing urban systems stress watersheds, resulting in water quality impacts downstream. Urban stresses can include nutrient runoff from fertilizer, effluent from wastewater treatment plants, and changes in hydrologic routing. Synoptic surveys were performed at two rivers in Salt Lake City, Utah to identify how urbanization drives dissolved organic matter (DOM) chemistry. Red Butte Creek, a small third order stream, flows from a protected mountain environment directly into a highly urbanized mountain area. The organic matter chemistry, as measured by fluorescence, changed dynamics in the urban system, with organic matter demonstrating greater aromaticity and different seasonal patterns than observed in the canyon. Several kilometers downstream of the start of urbanization, the C:N ratio of the organic matter changes from 12.5 to 17.7, at a location where the stream is fed by urban-impacted groundwater, suggesting that subsurface DOC is utilized for microbial respiration in denitrification of urban nitrate inputs. This also corresponds with a shift in the chemistry of the DOM, as measured by fluorescence. Red Butte Creek terminates at the Jordan River, which flows from a highly eutrophic lake and is fed by seven tributaries and five wastewater treatment plants before ending at the Great Salt Lake. The Jordan River is heavily contaminated, with low dissolved oxygen and high nutrient content. The fluorescence index (FI) of DOM in the Jordan River indicates a dominant microbial contribution to the fluorescent organic material, particularly in areas where the dissolved oxygen is low, with the FI becoming less microbial as the DO sag lessens. This corresponds to increasing fluorescence signal in the protein-like area of the fluorescence excitation-emission matrices. Additionally, effluent from four wastewater treatment plants, each with different technologies, had distinct organic matter fluorescence, corresponding with differences in the nitrogen and microbial dynamics downstream of the plants. These changes in fluorescence signal with degree of urban impact suggest the possibility of an identifiable fingerprint of urban influence on DOM fluorescence.

Identification of Oligosaccharides in Feces of Breast-fed Infants and Their Correlation with the Gut Microbial Community *

PubMed Central

Davis, Jasmine C. C.; Totten, Sarah M.; Huang, Julie O.; Nagshbandi, Sadaf; Kirmiz, Nina; Garrido, Daniel A.; Lewis, Zachery T.; Wu, Lauren D.; Smilowitz, Jennifer T.; German, J. Bruce; Mills, David A.; Lebrilla, Carlito B.

2016-01-01

Glycans in breast milk are abundant and found as either free oligosaccharides or conjugated to proteins and lipids. Free human milk oligosaccharides (HMOs) function as prebiotics by stimulating the growth of beneficial bacteria while preventing the binding of harmful bacteria to intestinal epithelial cells. Bacteria have adapted to the glycan-rich environment of the gut by developing enzymes that catabolize glycans. The decrease in HMOs and the increase in glycan digestion products give indications of the active enzymes in the microbial population. In this study, we quantitated the disappearance of intact HMOs and characterized the glycan digestion products in the gut that are produced by the action of microbial enzymes on HMOs and glycoconjugates from breast milk. Oligosaccharides from fecal samples of exclusively breast-fed infants were extracted and profiled using nanoLC-MS. Intact HMOs were found in the fecal samples, additionally, other oligosaccharides were found corresponding to degraded HMOs and non-HMO based compounds. The latter compounds were fragments of N-glycans released through the cleavage of the linkage to the asparagine residue and through cleavage of the chitobiose core of the N-glycan. Marker gene sequencing of the fecal samples revealed bifidobacteria as the dominant inhabitants of the infant gastrointestinal tracts. A glycosidase from Bifidobacterium longum subsp. longum was then expressed to digest HMOs in vitro, which showed that the digested oligosaccharides in feces corresponded to the action of glycosidases on HMOs. Similar expression of endoglycosidases also showed that N-glycans were released by bacterial enzymes. Although bifidobacteria may dominate the gut, it is possible that specific minority species are also responsible for the major products observed in feces. Nonetheless, the enzymatic activity correlated well with the known glycosidases in the respective bacteria, suggesting a direct relationship between microbial abundances and catabolic activity. PMID:27435585

Identification of Oligosaccharides in Feces of Breast-fed Infants and Their Correlation with the Gut Microbial Community.

PubMed

Davis, Jasmine C C; Totten, Sarah M; Huang, Julie O; Nagshbandi, Sadaf; Kirmiz, Nina; Garrido, Daniel A; Lewis, Zachery T; Wu, Lauren D; Smilowitz, Jennifer T; German, J Bruce; Mills, David A; Lebrilla, Carlito B

2016-09-01

Glycans in breast milk are abundant and found as either free oligosaccharides or conjugated to proteins and lipids. Free human milk oligosaccharides (HMOs) function as prebiotics by stimulating the growth of beneficial bacteria while preventing the binding of harmful bacteria to intestinal epithelial cells. Bacteria have adapted to the glycan-rich environment of the gut by developing enzymes that catabolize glycans. The decrease in HMOs and the increase in glycan digestion products give indications of the active enzymes in the microbial population. In this study, we quantitated the disappearance of intact HMOs and characterized the glycan digestion products in the gut that are produced by the action of microbial enzymes on HMOs and glycoconjugates from breast milk. Oligosaccharides from fecal samples of exclusively breast-fed infants were extracted and profiled using nanoLC-MS. Intact HMOs were found in the fecal samples, additionally, other oligosaccharides were found corresponding to degraded HMOs and non-HMO based compounds. The latter compounds were fragments of N-glycans released through the cleavage of the linkage to the asparagine residue and through cleavage of the chitobiose core of the N-glycan. Marker gene sequencing of the fecal samples revealed bifidobacteria as the dominant inhabitants of the infant gastrointestinal tracts. A glycosidase from Bifidobacterium longum subsp. longum was then expressed to digest HMOs in vitro, which showed that the digested oligosaccharides in feces corresponded to the action of glycosidases on HMOs. Similar expression of endoglycosidases also showed that N-glycans were released by bacterial enzymes. Although bifidobacteria may dominate the gut, it is possible that specific minority species are also responsible for the major products observed in feces. Nonetheless, the enzymatic activity correlated well with the known glycosidases in the respective bacteria, suggesting a direct relationship between microbial abundances and catabolic activity. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity

PubMed Central

Denou, Emmanuel; Marcinko, Katarina; Surette, Michael G.; Steinberg, Gregory R.

2016-01-01

Diet and exercise underpin the risk of obesity-related metabolic disease. Diet alters the gut microbiota, which contributes to aspects of metabolic disease during obesity. Repeated exercise provides metabolic benefits during obesity. We assessed whether exercise could oppose changes in the taxonomic and predicted metagenomic characteristics of the gut microbiota during diet-induced obesity. We hypothesized that high-intensity interval training (HIIT) would counteract high-fat diet (HFD)-induced changes in the microbiota without altering obesity in mice. Compared with chow-fed mice, an obesity-causing HFD decreased the Bacteroidetes-to-Firmicutes ratio and decreased the genetic capacity in the fecal microbiota for metabolic pathways such as the tricarboxylic acid (TCA) cycle. After HFD-induced obesity was established, a subset of mice were HIIT for 6 wk, which increased host aerobic capacity but did not alter body or adipose tissue mass. The effects of exercise training on the microbiota were gut segment dependent and more extensive in the distal gut. HIIT increased the alpha diversity and Bacteroidetes/Firmicutes ratio of the distal gut and fecal microbiota during diet-induced obesity. Exercise training increased the predicted genetic capacity related to the TCA cycle among other aspects of metabolism. Strikingly, the same microbial metabolism indexes that were increased by exercise were all decreased in HFD-fed vs. chow diet-fed mice. Therefore, exercise training directly opposed some of the obesity-related changes in gut microbiota, including lower metagenomic indexes of metabolism. Some host and microbial pathways appeared similarly affected by exercise. These exercise- and diet-induced microbiota interactions can be captured in feces. PMID:27117007

High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity.

PubMed

Denou, Emmanuel; Marcinko, Katarina; Surette, Michael G; Steinberg, Gregory R; Schertzer, Jonathan D

2016-06-01

Diet and exercise underpin the risk of obesity-related metabolic disease. Diet alters the gut microbiota, which contributes to aspects of metabolic disease during obesity. Repeated exercise provides metabolic benefits during obesity. We assessed whether exercise could oppose changes in the taxonomic and predicted metagenomic characteristics of the gut microbiota during diet-induced obesity. We hypothesized that high-intensity interval training (HIIT) would counteract high-fat diet (HFD)-induced changes in the microbiota without altering obesity in mice. Compared with chow-fed mice, an obesity-causing HFD decreased the Bacteroidetes-to-Firmicutes ratio and decreased the genetic capacity in the fecal microbiota for metabolic pathways such as the tricarboxylic acid (TCA) cycle. After HFD-induced obesity was established, a subset of mice were HIIT for 6 wk, which increased host aerobic capacity but did not alter body or adipose tissue mass. The effects of exercise training on the microbiota were gut segment dependent and more extensive in the distal gut. HIIT increased the alpha diversity and Bacteroidetes/Firmicutes ratio of the distal gut and fecal microbiota during diet-induced obesity. Exercise training increased the predicted genetic capacity related to the TCA cycle among other aspects of metabolism. Strikingly, the same microbial metabolism indexes that were increased by exercise were all decreased in HFD-fed vs. chow diet-fed mice. Therefore, exercise training directly opposed some of the obesity-related changes in gut microbiota, including lower metagenomic indexes of metabolism. Some host and microbial pathways appeared similarly affected by exercise. These exercise- and diet-induced microbiota interactions can be captured in feces. Copyright © 2016 the American Physiological Society.

Effects of grain source, grain processing, and protein degradability on rumen kinetics and microbial protein synthesis in Boer kids.

PubMed

Brassard, M-E; Chouinard, P Y; Berthiaume, R; Tremblay, G F; Gervais, R; Martineau, R; Cinq-Mars, D

2015-11-01

Microbial protein synthesis in the rumen would be optimized when dietary carbohydrates and proteins have synchronized rates and extent of degradation. The aim of this study was to evaluate the effect of varying ruminal degradation rate of energy and nitrogen sources on intake, nitrogen balance, microbial protein yield, and kinetics of nutrients in the rumen of growing kids. Eight Boer goats (38.2 ± 3.0 kg) were used. The treatments were arranged in a split-plot Latin square design with grain sources (barley or corn) forming the main plots (squares). Grain processing methods and levels of protein degradability formed the subplots in a 2 × 2 factorial arrangement for a total of 8 dietary treatments. The grain processing method was rolling for barley and cracking for corn. Levels of protein degradability were obtained by feeding untreated soybean meal (SBM) or heat-treated soybean meal (HSBM). Each experimental period lasted 21 d, consisting of a 10-d adaptation period, a 7-d digestibility determination period, and a 4-d rumen evacuation and sampling period. Kids fed with corn had higher purine derivatives (PD) excretion when coupled with SBM compared with HSBM and the opposite occurred with barley-fed kids ( ≤ 0.01). Unprocessed grain offered with SBM led to higher PD excretion than with HSBM whereas protein degradability had no effect when processed grain was fed ( ≤ 0.03). Results of the current experiment with high-concentrate diets showed that microbial N synthesis could be maximized in goat kids by combining slowly fermented grains (corn or unprocessed grains) with a highly degradable protein supplement (SBM). With barley, a more rapidly fermented grain, a greater microbial N synthesis was observed when supplementing a low-degradable protein (HSBM).

Characterization of a filamentous biofilm community established in a cellulose-fed microbial fuel cell.

PubMed

Ishii, Shun'ichi; Shimoyama, Takefumi; Hotta, Yasuaki; Watanabe, Kazuya

2008-01-10

Microbial fuel cells (MFCs) are devices that exploit microorganisms to generate electric power from organic matter. Despite the development of efficient MFC reactors, the microbiology of electricity generation remains to be sufficiently understood. A laboratory-scale two-chamber microbial fuel cell (MFC) was inoculated with rice paddy field soil and fed cellulose as the carbon and energy source. Electricity-generating microorganisms were enriched by subculturing biofilms that attached onto anode electrodes. An electric current of 0.2 mA was generated from the first enrichment culture, and ratios of the major metabolites (e.g., electric current, methane and acetate) became stable after the forth enrichment. In order to investigate the electrogenic microbial community in the anode biofilm, it was morphologically analyzed by electron microscopy, and community members were phylogenetically identified by 16S rRNA gene clone-library analyses. Electron microscopy revealed that filamentous cells and rod-shaped cells with prosthecae-like filamentous appendages were abundantly present in the biofilm. Filamentous cells and appendages were interconnected via thin filaments. The clone library analyses frequently detected phylotypes affiliated with Clostridiales, Chloroflexi, Rhizobiales and Methanobacterium. Fluorescence in-situ hybridization revealed that the Rhizobiales population represented rod-shaped cells with filamentous appendages and constituted over 30% of the total population. Bacteria affiliated with the Rhizobiales constituted the major population in the cellulose-fed MFC and exhibited unique morphology with filamentous appendages. They are considered to play important roles in the cellulose-degrading electrogenic community.

Characterization of a filamentous biofilm community established in a cellulose-fed microbial fuel cell

PubMed Central

Ishii, Shun'ichi; Shimoyama, Takefumi; Hotta, Yasuaki; Watanabe, Kazuya

2008-01-01

Background Microbial fuel cells (MFCs) are devices that exploit microorganisms to generate electric power from organic matter. Despite the development of efficient MFC reactors, the microbiology of electricity generation remains to be sufficiently understood. Results A laboratory-scale two-chamber microbial fuel cell (MFC) was inoculated with rice paddy field soil and fed cellulose as the carbon and energy source. Electricity-generating microorganisms were enriched by subculturing biofilms that attached onto anode electrodes. An electric current of 0.2 mA was generated from the first enrichment culture, and ratios of the major metabolites (e.g., electric current, methane and acetate) became stable after the forth enrichment. In order to investigate the electrogenic microbial community in the anode biofilm, it was morphologically analyzed by electron microscopy, and community members were phylogenetically identified by 16S rRNA gene clone-library analyses. Electron microscopy revealed that filamentous cells and rod-shaped cells with prosthecae-like filamentous appendages were abundantly present in the biofilm. Filamentous cells and appendages were interconnected via thin filaments. The clone library analyses frequently detected phylotypes affiliated with Clostridiales, Chloroflexi, Rhizobiales and Methanobacterium. Fluorescence in-situ hybridization revealed that the Rhizobiales population represented rod-shaped cells with filamentous appendages and constituted over 30% of the total population. Conclusion Bacteria affiliated with the Rhizobiales constituted the major population in the cellulose-fed MFC and exhibited unique morphology with filamentous appendages. They are considered to play important roles in the cellulose-degrading electrogenic community. PMID:18186940

Evaluation of the ruminal bacterial diversity of cattle fed diets containing citrus pulp pellets

USDA-ARS?s Scientific Manuscript database

The rumen microbial ecosystem remains a mystery from a quantitative perspective. Dietary components and changes cause shifts in the ruminal microbial ecology that can play a role in animal health and productivity, but the magnitude of these changes remains unknown. The objective of this study was ...

Evaluation of various cheese whey treatment scenarios in single-chamber microbial electrolysis cells for improved biohydrogen production.

PubMed

Rivera, Isaac; Bakonyi, Péter; Cuautle-Marín, Manuel Alejandro; Buitrón, Germán

2017-05-01

In this study single-chamber microbial electrolysis cells (MECs) were applied to treat cheese whey (CW), an industrial by-product, and recover H 2 gas. Firstly, this substrate was fed directly to the MEC to get the initial feedback about its H 2 generation potential. The results indicated that the direct application of CW requires an adequate pH control to realize bioelectrohydrogenesis and avoid operational failure due to the loss of bioanode activity. In the second part of the study, the effluents of anaerobic (methanogenic) digester and hydrogenogenic (dark fermentative H 2 -producing) reactor utilizing the CW were tested in the MEC process (representing the concept of a two-stage technology). It turned out that the residue of the methanogenic reactor - with its relatively lower carbohydrate- and higher volatile fatty acid contents - was more suitable to produce hydrogen bioelectrochemically. The MEC operated with the dark fermentation effluent, containing a high portion of carbohydrates and low amount of organic acids, produced significant amount of undesired methane simultaneously with H 2 . Overall, the best MEC behavior was attained using the effluent of the methanogenic reactor and therefore, considering a two-stage system, methanogenesis is an advisable pretreatment step for the acidic CW to enhance the H 2 formation in complementary microbial electrohydrogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rumen microbial changes in cattle fed diets with or without salinomycin.

PubMed

Olumeyan, D B; Nagaraja, T G; Miller, G W; Frey, R A; Boyer, J E

1986-02-01

Four rumen-fistulated steers, randomly assigned to two groups (control and salinomycin fed) were used to monitor the changes in rumen microbial populations and volatile fatty acids (VFA) concentrations associated with feeding salinomycin (0.22 mg X kg-1 X day-1). Steers were adapted to an alfalfa hay and grain (80:20) diet before supplementing the diet with salinomycin, and then the diet was changed to 50:50 and 20:80 ratios of alfalfa hay to grain at 2-week intervals. Rumen samples for total and selective enumeration of anaerobic bacteria. VFA analysis, and enumeration of protozoa were collected during the 80:20 alfalfa hay-to-grain diet before salinomycin feeding, and during the 80:20, 50:50, and 20:80 hay-to-grain diets with salinomycin. At each sampling period, rumen samples were collected at 3 h after feeding on three consecutive days. Salinomycin feeding had no effect on rumen pH and total VFA concentration. The acetate-to-propionate ratio was significantly lower in salinomycin-fed steers than in the control. The molar proportion of butyrate increased in both control and salinomycin-fed steers. Total anaerobic bacterial counts were lower in salinomycin-fed steers than in the control steers after 8 weeks of salinomycin feeding. Salinomycin-resistant bacteria increased from 7.6 to 15.6% in salinomycin-fed steers but remained unchanged in control steers. Salinomycin had no effect on cellulolytic and lactate-utilizing bacteria, but the proportion of amylolytic bacteria was higher in salinomycin-fed steers than in control steers. The total number of protozoa decreased initially in salinomycin-fed steers. The initial reduction was due to reduced numbers of Entodinium species. Holotrichs were unaffected by salinomycin feeding.

¹³C Pathway Analysis for the Role of Formate in Electricity Generation by Shewanella Oneidensis MR-1 Using Lactate in Microbial Fuel Cells.

PubMed

Luo, Shuai; Guo, Weihua; Nealson, Kenneth H; Feng, Xueyang; He, Zhen

2016-02-12

Microbial fuel cell (MFC) is a promising technology for direct electricity generation from organics by microorganisms. The type of electron donors fed into MFCs affects the electrical performance, and mechanistic understanding of such effects is important to optimize the MFC performance. In this study, we used a model organism in MFCs, Shewanella oneidensis MR-1, and (13)C pathway analysis to investigate the role of formate in electricity generation and the related microbial metabolism. Our results indicated a synergistic effect of formate and lactate on electricity generation, and extra formate addition on the original lactate resulted in more electrical output than using formate or lactate as a sole electron donor. Based on the (13)C tracer analysis, we discovered decoupled cell growth and electricity generation in S. oneidensis MR-1 during co-utilization of lactate and formate (i.e., while the lactate was mainly metabolized to support the cell growth, the formate was oxidized to release electrons for higher electricity generation). To our best knowledge, this is the first time that (13)C tracer analysis was applied to study microbial metabolism in MFCs and it was demonstrated to be a valuable tool to understand the metabolic pathways affected by electron donors in the selected electrochemically-active microorganisms.

Microbiome-Metabolome Responses in the Cecum and Colon of Pig to a High Resistant Starch Diet.

PubMed

Sun, Yue; Su, Yong; Zhu, Weiyun

2016-01-01

Currently, knowledge about the impact of long-term intake of high resistant starch diet on pig hindgut microbiota and metabolite profile is limited. In this study, a combination of the pyrosequencing and the mass spectrometry (MS)-based metabolomics techniques were used to investigate the effects of a raw potato starch (RPS, high in resistant starch) diet on microbial composition and microbial metabolites in the hindgut of pig. The results showed that Coprococcus, Ruminococcus, and Turicibacter increased significantly, while Sarcina and Clostridium decreased in relative abundances in the hindgut of pigs fed RPS. The metabolimic analysis revealed that RPS significantly affected starch and sucrose metabolites, amino acid turnover or protein biosynthesis, lipid metabolites, glycolysis, the pentose phosphate pathway, inositol phosphate metabolism, and nucleotide metabolism. Furthermore, a Pearson's correlation analysis showed that Ruminococcus and Coprococcus were positively correlated with glucose-6-phosphate, maltose, arachidonic acid, 9, 12-octadecadienoic acid, oleic acid, phosphate, but negatively correlated with α-aminobutyric acid. However, the correlation of Clostridium and Sarcina with these compounds was in the opposite direction. The results suggest that RPS not only alters the composition of the gut microbial community but also modulates the metabolic pathway of microbial metabolism, which may further affect the hindgut health of the host.

Microbiome-Metabolome Responses in the Cecum and Colon of Pig to a High Resistant Starch Diet

PubMed Central

Sun, Yue; Su, Yong; Zhu, Weiyun

2016-01-01

Currently, knowledge about the impact of long-term intake of high resistant starch diet on pig hindgut microbiota and metabolite profile is limited. In this study, a combination of the pyrosequencing and the mass spectrometry (MS)-based metabolomics techniques were used to investigate the effects of a raw potato starch (RPS, high in resistant starch) diet on microbial composition and microbial metabolites in the hindgut of pig. The results showed that Coprococcus, Ruminococcus, and Turicibacter increased significantly, while Sarcina and Clostridium decreased in relative abundances in the hindgut of pigs fed RPS. The metabolimic analysis revealed that RPS significantly affected starch and sucrose metabolites, amino acid turnover or protein biosynthesis, lipid metabolites, glycolysis, the pentose phosphate pathway, inositol phosphate metabolism, and nucleotide metabolism. Furthermore, a Pearson's correlation analysis showed that Ruminococcus and Coprococcus were positively correlated with glucose-6-phosphate, maltose, arachidonic acid, 9, 12-octadecadienoic acid, oleic acid, phosphate, but negatively correlated with α-aminobutyric acid. However, the correlation of Clostridium and Sarcina with these compounds was in the opposite direction. The results suggest that RPS not only alters the composition of the gut microbial community but also modulates the metabolic pathway of microbial metabolism, which may further affect the hindgut health of the host. PMID:27303373

Comparative effect of direct-fed microbials on fecal shedding of Escherichia coli O157:H7 and Salmonella in naturally infected feedlot cattle.

PubMed

Tabe, Ebot S; Oloya, James; Doetkott, Dawn K; Bauer, Marc L; Gibbs, Penelope S; Khaitsa, Margaret L

2008-03-01

The effect of direct-fed microbials (DFM) on fecal shedding of Escherichia coli O157:H7 and Salmonella in naturally infected feedlot cattle was evaluated in a clinical trial involving 138 feedlot steers. Following standard laboratory methods, fecal samples collected from steers were evaluated for change in the detectable levels of E. coli O157:H7 and Salmonella shed in feces after DFM treatment. Sampling of steers was carried out every 3 weeks for 84 days. A significant reduction (32%) in fecal shedding of E. coli O157:H7 (P < 0.001), but not Salmonella (P = 0.24), was observed among the treatment steers compared with the control group during finishing. The probability of recovery of E. coli O157:H7 from the feces of treated and control steers was 34.0 and 66.0%, respectively. Steers placed on DFM supplement were almost three times less likely to shed E. coli O157:H7 (odds ratio, 0.36; 95% confidence interval, 0.25 to 0.53; P < 0.001) in their feces as opposed to their control counterparts. The probability of recovery of Salmonella from the feces of the control (14.0%) and the treated (11.3%) steers was similar. However, the DFM significantly reduced probability of new infections with Salmonella among DFM-treated cattle compared with controls (nontreated ones). It appears that DFM as applied in our study are capable of significantly reducing fecal shedding of E. coli O157:H7 in naturally infected cattle but not Salmonella. The factors responsible for the observed difference in the effects of DFM on E. coli O157:H7 and Salmonella warrants further investigation.

Microbial community dynamics in continuous microbial fuel cells fed with synthetic wastewater and pig slurry.

PubMed

Sotres, Ana; Tey, Laura; Bonmatí, August; Viñas, Marc

2016-10-01

Two-chambered microbial fuel cells (MFCs) operating with synthetic wastewater and pig slurry were assessed. Additionally, the use of 2-bromoethanesulfonate (BES-Inh) was studied. The synthetic wastewater-fed MFC (MFCSW) showed a maximum power density (PDmax) of 2138mWm(-3), and the addition of BES-Inh (10mM) did not show any improvement in its performance (PDmax=2078mWm(-3)). When pig slurry was used as feed (MFCPS), PDmax increased up to 5623mWm(-3). The microbial community composition was affected by the type of substrate used. While, Pseudomonadaceae and Clostridiaceae were the most representative families within the acetate-based medium, Flavobacteriaceae, Chitinophagaceae, Comamonadaceae and Nitrosomonadaceae were predominant when pig slurry was used as feed. Otherwise, only the Eubacterial microbial community composition was strongly modified when adding BES-Inh, thus leading to an enrichment of the Bacteroidetes phylum. Oppositely, the Archaeal community was less affected by the addition of BES-Inh, and Methanosarcina sp., arose as the predominant family in both situations. Despite all the differences in microbial communities, 6 operational taxonomic units (OTUs) belonging to Bacteroidetes (Porphyromonadaceae and Marinilabiaceae) and Firmicutes (Clostridiales) were found to be common to both MFCs, also for different contents of COD and N-NH4(+), and therefore could be considered as the bioanode core microbiome. Copyright © 2016 Elsevier B.V. All rights reserved.

Prevalence of Escherichia coli O157:H7 and performance by beef feedlot cattle given Lactobacillus direct-fed microbials.

PubMed

Brashears, M M; Galyean, M L; Loneragan, G H; Mann, J E; Killinger-Mann, K

2003-05-01

Fecal shedding of Escherichia coli O157:H7, the prevalence of Escherichia coli O157:H7 in pens and on carcasses and hides, and cattle performance as a result of daily dietary supplementation with Lactobacillus-based direct-fed microbials (DFMs) were evaluated in a feeding trial involving 180 beef steers. Steers were evaluated for shedding of E. coli O157:H7 by an immunomagnetic separation technique on arrival at the feedlot, just before treatment with the DFMs, and every 14 days thereafter until slaughter. Composite pen fecal samples were collected every 14 days (alternating weeks with animal testing), and prevalence on hides and carcasses at slaughter was also evaluated. Feedlot performance (body weight gain and feed intake) was measured for the period during which the DFMs were fed. Gain efficiency was calculated as the ratio of weight gain to feed intake. Lactobacillus acidophilus NPC 747 decreased (P < 0.01) the shedding of E. coli O157:H7 in the feces of individual cattle during the feeding period. E. coli O157:H7 was approximately twice as likely to be detected in control animal samples as in samples from animals receiving L. acidophilus NPC 747. In addition, DFM supplementation decreased (P < 0.05) the number of E. coli O157:H7-positive hide samples at harvest and the number of pens testing positive for the pathogen. Body weight gains (on a live or carcass basis) and feed intakes during the DFM supplementation period did not differ among treatments. Gain efficiencies on a live-weight basis did not differ among treatments, but carcass-based gain/feed ratios tended (P < 0.06) to be better for animals receiving the two DFM treatments than for control animals. The results of this study suggest that the feeding of a Lactobacillus-based DFM to cattle will decrease, but not eliminate, fecal shedding of E. coli O157:H7, as well as contamination on hides, without detrimental effects on performance.

Ruminal changes in monensin- and lasalocid-fed cattle grazing bloat-provocative alfalfa pasture.

PubMed

Katz, M P; Nagaraja, T G; Fina, L R

1986-10-01

Microbial and fermentation changes in the rumen in monensin- and lasalocid-fed cattle grazing bloat-provocative alfalfa pasture were studied using genetically bloat-susceptible, ruminally-cannulated adult cattle. Monensin at .66 and .99 mg/kg body weight daily reduced the severity of legume bloat by 41 and 73%, respectively. The same doses of lasalocid reduced bloat by 25 and 12%. Comparison of ruminal contents from animals before treatment with ruminal contents from antibiotic-treated animals showed no differences in pH, ammonia, soluble N, soluble carbohydrate, ethanol-precipitable slime and anaerobic bacterial counts. Monensin treatment decreased protozoal numbers and microbial activity, as evidenced by lower gas production from in vitro fermentation of ground alfalfa hay when compared to pretreatment. Lasalocid had no effect on protozoal counts and in vitro gas production. Addition of monensin or lasalocid (12 micrograms/ml) to in vitro fermentation of chopped, fresh alfalfa reduced microbial activity as evidenced by higher soluble N, lower ammonia concentration and decreased gas production. Monensin reduced the amount of ethanol-precipitable slime and protozoal numbers. Reduction in the severity of bloat when monensin was fed appears to be due to decreased protozoal numbers, which resulted in decreased gas production. Lasalocid did not reduce legume bloat because of its minimal effect on the ruminal protozoa.

Direct-fed microbials containing lactate-producing bacteria influence ruminal fermentation but not lactate utilization in steers fed a high-concentrate diet.

PubMed

Kenney, N M; Vanzant, E S; Harmon, D L; McLeod, K R

2015-05-01

Direct-fed microbials (DFM) have been shown to improve gain and growth efficiency and also modulate ruminal fermentation. In Exp. 1,72 beef steers were used to compare a lactate-producing bacterial (LAB) DFM consisting primarily of Lactobacillus acidophilus and Enterococcus faecium,and a lactate-producing and lactate-utilizing (LAB/LU) DFM consisting primarily of L. acidophilus and Propionibacterium both fed at 10(9) cfu/d. Steers were fed a corn-based finishing diet for 153 d and then slaughtered for collection of carcass characteristics. In Exp. 2, 12 ruminally cannulated steers were fed acorn-based finishing diet and treated with 10(9) cfu/d of LAB DFM. Rumen fluid was sampled on d 14 and 28 over a 12-h period. Steers were ruminally dosed with a 2-L solution of neutralized DL-lactate (0.56 M)and Cr-EDTA (13.22 M) 3 h postfeeding on d 15 and 29. Ruminal samples were collected at 10- and 20-minintervals for the first and second hour postdosing. No differences (P ≥ 0.14) between control (CON) and LAB for DMI, ADG, growth efficiency, or carcass characteristics were observed. Dry matter intake was greater (P = 0.04) for LAB/LU than LAB from d 0 to 28 but did not differ (P ≥ 0.29) thereafter. Average daily gain was greater (P = 0.04) and efficiency tended(P = 0.06) to be greater for LAB than LAB/LU over the entire 153 d. In Exp. 2, total VFA concentration and molar proportions of butyrate were unaffected(P ≥ 0.24). Molar proportions of acetate exhibited a DFM by hour interaction (P = 0.04); however, on average, molar proportion of acetate was 4.4% greater for DFM. Conversely, DFM did not affect the molar proportion of propionate (P = 0.39). On average,molar proportions of propionate tended to increase(P = 0.07), and acetate tended to decrease (P = 0.07)across days. Mean daily ruminal pH was similar for CON on d 14 and 28, whereas mean pH increased from d 14 to 28 for DFM (DFM × day; P = 0.08).Minimum pH remained unchanged for CON over time but increased from d 14 to 2 for DFM (DFM × day;P = 0.10). Maximum pH decreased from d 14 to 28 in CON but increased over time with DFM (DFM × day;P = 0.05). DL- and L-lactate utilization were unaffected by DFM (P ≥ 0.33) or day (P ≥ 0.50). Although the LAB DFM did not impact growth performance, itd id modulate ruminal fermentation, as evidenced by shifts in ruminal VFA profile and pH; however, DFM did not appear to influence ruminal lactate utilization.

Prebiotic milk oligosaccharides prevent development of obese phenotype, impairment of gut permeability, and microbial dysbiosis in high fat-fed mice

USDA-ARS?s Scientific Manuscript database

Objective: Microbial dysbiosis and increased intestinal permeability is a target for prevention or reversal of weight gain in high-fat (HF) diet-induced obesity (DIO); however, it is not known whether decreased intestinal permeability is necessary or sufficient for weight loss. Prebiotic milk oligos...

Effects of alfalfa meal on the intestinal microbial diversity and immunity of growing ducks.

PubMed

Jiang, J F; Song, X M; Wu, J L; Jiang, Y Q

2014-12-01

This study was conducted to investigate the effects of alfalfa meal diets on the intestinal microbial diversity and immunity of growing egg-type ducks. A total of 128 healthy 7-week-old female egg-type Shaoxing ducks were selected and randomly assigned into four dietary treatments: 0%, 3%, 6% and 9% alfalfa meal for 8 weeks. Each treatment consisted of four replicates of eight ducks each. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) was used to characterize the microbiota. The results showed that the DGGE fingerprints of the V6-V8 fragments of the 16S rRNA from the caeca and faeces of ducks fed 3%, 6% and 9% alfalfa meal had significantly higher microbiota species richness than those fed 0% alfalfa meal (p < 0.05). The Shannon-Weiner index of the microbiota from the caeca and faeces of ducks fed 3%, 6% and 9% alfalfa meal was significantly higher than those fed 0% alfalfa meal (p < 0.05). Molecular analysis of the caecal and faecal DNA extracts showed that the alfalfa meal diet promotes the intestinal microbial diversity, as indicated by their higher species richness and Shannon-Weiner index. However, the groups did not significantly differ in terms of average daily gain, feed intake and gain-to-feed ratio (p > 0.05), and the 3-9% alfalfa meal did not affect the growth performance of the growing egg-type ducks. The proliferation of T and B lymphocytes was significantly greater (p < 0.05) in the groups supplemented with 3%, 6% and 9% of alfalfa meal than the unsupplemented control group, and alfalfa meal promoted the lymphocytes proliferation of the growing egg-type ducks. Dietary alfalfa meal supplementation increases intestinal microbial community diversity and improves of the immune response growing egg-type ducks. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Microbial anodic consortia fed with fermentable substrates in microbial electrolysis cells: Significance of microbial structures.

PubMed

Flayac, Clément; Trably, Eric; Bernet, Nicolas

2018-05-28

Microbial community structure of anodic biofilms plays a key role in bioelectrochemical systems (BESs). When ecosystems are used as inocula, many bacterial species having interconnected ecological interactions are present. The aim of the present study was to identify these interactions for the conversion of single substrates into electrical current. Dual-chamber reactors were inoculated with activated sludge and fed in batch mode with acetate, lactate, butyrate and propionate at 80 mMe - equivalents in quadruplicate. Analyses of biofilms and planktonic microbial communities showed that the anodic biofilms were mainly dominated by the Geobacter genus (62.4% of the total sequences). At the species level, Geobacter sulfurreducens was dominant in presence of lactate and acetate, while Geobacter toluenoxydans and Geobacter pelophilus were dominant with butyrate and propionate as substrates. These results indicate for the first time a specificity within the Geobacter genus towards the electron donor, suggesting a competitive process for electrode colonization and the implementations of syntrophic interactions for complete oxidation of substrates such as propionate and butyrate. All together, these results provide a new insight into the ecological relationships within electroactive biofilms and suggest eco-engineering perspectives to improve the performances of BESs. Copyright © 2018 Elsevier B.V. All rights reserved.

Model-based intensification of a fed-batch microbial process for the maximization of polyhydroxybutyrate (PHB) production rate.

PubMed

Penloglou, Giannis; Vasileiadou, Athina; Chatzidoukas, Christos; Kiparissides, Costas

2017-08-01

An integrated metabolic-polymerization-macroscopic model, describing the microbial production of polyhydroxybutyrate (PHB) in Azohydromonas lata bacteria, was developed and validated using a comprehensive series of experimental measurements. The model accounted for biomass growth, biopolymer accumulation, carbon and nitrogen sources utilization, oxygen mass transfer and uptake rates and average molecular weights of the accumulated PHB, produced under batch and fed-batch cultivation conditions. Model predictions were in excellent agreement with experimental measurements. The validated model was subsequently utilized to calculate optimal operating conditions and feeding policies for maximizing PHB productivity for desired PHB molecular properties. More specifically, two optimal fed-batch strategies were calculated and experimentally tested: (1) a nitrogen-limited fed-batch policy and (2) a nitrogen sufficient one. The calculated optimal operating policies resulted in a maximum PHB content (94% g/g) in the cultivated bacteria and a biopolymer productivity of 4.2 g/(l h), respectively. Moreover, it was demonstrated that different PHB grades with weight average molecular weights of up to 1513 kg/mol could be produced via the optimal selection of bioprocess operating conditions.

Effects of the feeding ratio of food waste on fed-batch aerobic composting and its microbial community.

PubMed

Wang, Xiaojun; Pan, Songqing; Zhang, Zhaoji; Lin, Xiangyu; Zhang, Yuzhen; Chen, Shaohua

2017-01-01

To determine the suitable feeding ratio for fed-batch aerobic composting, four fermenters were operated by adding 0%, 5%, 10% or 15% of food waste every day. The results showed that the 5% and 10% treatments were able to maintain continuous thermophilic conditions, while the 15% treatment performed badly in regard to composting temperature, which was probably due to the negative effects of excessive moisture on microbial activity. As composting proceeded, both the 5% and the 10% treatments reached maturity and achieved weight losses of approximately 65%. High-throughput sequencing results indicated that Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria were the dominant phyla of the community structure. The communities sampled at the thermophilic phases had high similarity and relatively low diversity, while species diversity increased in the maturity phase. This study was devoted to optimizing the fed-batch composting process and assessing bacterial communities, both of which were supplied as a reference for practical application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multiple syntrophic interactions drive biohythane production from waste sludge in microbial electrolysis cells.

PubMed

Liu, Qian; Ren, Zhiyong Jason; Huang, Cong; Liu, Bingfeng; Ren, Nanqi; Xing, Defeng

2016-01-01

Biohythane is a new and high-value transportation fuel present as a mixture of biomethane and biohydrogen. It has been produced from different organic matters using anaerobic digestion. Bioenergy can be recovered from waste activated sludge through methane production during anaerobic digestion, but energy yield is often insufficient to sludge disposal. Microbial electrolysis cell (MEC) is also a promising approach for bioenergy recovery and waste sludge disposal as higher energy efficiency and biogas production. The systematic understanding of microbial interactions and biohythane production in MEC is still limited. Here, we report biohythane production from waste sludge in biocathode microbial electrolysis cells and reveal syntrophic interactions in microbial communities based on high-throughput sequencing and quantitative PCR targeting 16S rRNA gene. The alkali-pretreated sludge fed MECs (AS-MEC) showed the highest biohythane production rate of 0.148 L·L(-1)-reactor·day(-1), which is 40 and 80 % higher than raw sludge fed MECs (RS-MEC) and anaerobic digestion (open circuit MEC, RS-OCMEC). Current density, metabolite profiles, and hydrogen-methane ratio results all confirm that alkali-pretreatment and microbial electrolysis greatly enhanced sludge hydrolysis and biohythane production. Illumina Miseq sequencing of 16S rRNA gene amplicons indicates that anode biofilm was dominated by exoelectrogenic Geobacter, fermentative bacteria and hydrogen-producing bacteria in the AS-MEC. The cathode biofilm was dominated by fermentative Clostridium. The dominant archaeal populations on the cathodes of AS-MEC and RS-MEC were affiliated with hydrogenotrophic Methanobacterium (98 %, relative abundance) and Methanocorpusculum (77 %), respectively. Multiple pathways of gas production were observed in the same MEC reactor, including fermentative and electrolytic H2 production, as well as hydrogenotrophic methanogenesis and electromethanogenesis. Real-time quantitative PCR analyses showed that higher amount of methanogens were enriched in AS-MEC than that in RS-MEC and RS-OCMEC, suggesting that alkali-pretreated sludge and MEC facilitated hydrogenotrophic methanogen enrichment. This study proves for the first time that biohythane could be produced directly in biocathode MECs using waste sludge. MEC and alkali-pretreatment accelerated enrichment of hydrogenotrophic methanogen and hydrolysis of waste sludge. The results indicate syntrophic interactions among fermentative bacteria, exoelectrogenic bacteria and methanogenic archaea in MECs are critical for highly efficient conversion of complex organics into biohythane, demonstrating that MECs can be more competitive than conventional anaerobic digestion for biohythane production using carbohydrate-deficient substrates. Biohythane production from waste sludge by MEC provides a promising new way for practical application of microbial electrochemical technology.

Combination of an Enzymatically Hydrolyzed Yeast and Yeast Culture with a Direct-fed Microbial in the Feeds of Broiler Chickens

PubMed Central

Gómez, S.; Angeles, M. L.; Mojica, M. C.; Jalukar, S.

2012-01-01

A balance trial experiment was carried out to evaluate the potential relationship between an enzymatically hydrolyzed yeast (EHY) and yeast culture combined with a live Bacillus subtilis (Bs) on the productive parameters, ileal digestibility, retention of nutrient and energy and villus morphology in broilers. Seventy two 28 d old, Ross B308 male broilers were assigned to a factorial combination of 2 levels of EHY (0 and 1 kg/ton of feed) and 2 levels of Bs (0 and 125 g/ton of feed). The experiment lasted 2 weeks. Several treatment interactions were observed. EHY-fed broilers showed the lowest feed intake and feed conversion ratio whereas Bs-fed broilers showed the highest feed intake and intermediate feed conversion ratio (EHY and BS interaction, p<0.05). Also, EHY-fed broilers had greater ileal digestibility of dry matter (EHY and BS interaction, p<0.01) and energy (EHY and BS interaction, p<0.05) but these responses were counterbalanced by the combination of EHY and Bs. The thickness of the mucosa was similar between the control and EHY-fed broilers, but was lowest when Bs was added alone (EHY and BS interaction, p<0.01). The thickness of the villus was greater in EHY plus Bs-fed broilers, intermediate for the control and lower for Bs or EHY-fed broilers (EHY and BS interaction, p<0.05). The area of the villus was greater in the control and EHY plus Bs-fed broilers (EHY and BS interaction, p<0.05). In addition, EHY-fed broilers showed greater breast yield and nitrogen retention (p<0.01) and ashes digestibility (p<0.05). On the other hand, Bs-fed broilers had greater carcass and breast weight, nitrogen retention, energy excretion and villus height (p<0.05). In summary, EHY and Bs enhanced some growth, carcass and nutrient retention responses, but did not show any synergic relationship in these responses. Opposite to this, the results suggest that the positive effect of EHY on the feed conversion and digestibility of nutrients were counterbalanced by the addition of Bs. PMID:25049612

An investigation into the preservation of microbial cell banks for α-amylase production during 5 l fed-batch Bacillus licheniformis fermentations.

PubMed

Hancocks, Nichola H; Thomas, Colin R; Stocks, Stuart M; Hewitt, Christopher J

2010-10-01

Fluorescent staining techniques were used for a systematic examination of methods used to cryopreserve microbial cell banks. The aim of cryopreservation here is to ensure subsequent reproducible fermentation performance rather than just post thaw viability. Bacillus licheniformis cell physiology post-thaw is dependent on the cryopreservant (either Tween 80, glycerol or dimethyl sulphoxide) and whilst this had a profound effect on the length of the lag phase, during subsequent 5 l fed-batch fermentations, it had little effect on maximum specific growth rate, final biomass concentration or α-amylase activity. Tween 80 not only protected the cells during freezing but also helped them recover post-thaw resulting in shorter process times.

High-fat, high-fructose, high-cholesterol feeding causes severe NASH and cecal microbiota dysbiosis in juvenile Ossabaw swine.

PubMed

Panasevich, M R; Meers, G M; Linden, M A; Booth, F W; Perfield, J W; Fritsche, K L; Wankhade, Umesh D; Chintapalli, Sree V; Shankar, K; Ibdah, J A; Rector, R S

2018-01-01

Pediatric obesity and nonalcoholic steatohepatitis (NASH) are on the rise in industrialized countries, yet our ability to mechanistically examine this relationship is limited by the lack of a suitable higher animal models. Here, we examined the effects of high-fat, high-fructose corn syrup, high-cholesterol Western-style diet (WD)-induced obesity on NASH and cecal microbiota dysbiosis in juvenile Ossabaw swine. Juvenile female Ossabaw swine (5 wk old) were fed WD (43.0% fat; 17.8% high-fructose corn syrup; 2% cholesterol) or low-fat diet (CON/lean; 10.5% fat) for 16 wk ( n = 6 each) or 36 wk ( n = 4 each). WD-fed pigs developed obesity, dyslipidemia, and systemic insulin resistance compared with CON pigs. In addition, obese WD-fed pigs developed severe NASH, with hepatic steatosis, hepatocyte ballooning, inflammatory cell infiltration, and fibrosis after 16 wk, with further exacerbation of histological inflammation and fibrosis after 36 wk of WD feeding. WD feeding also resulted in robust cecal microbiota changes including increased relative abundances of families and genera in Proteobacteria ( P < 0.05) (i.e., Enterobacteriaceae, Succinivibrionaceae, and Succinivibrio) and LPS-containing Desulfovibrionaceae and Desulfovibrio and a greater ( P < 0.05) predicted microbial metabolic function for LPS biosynthesis, LPS biosynthesis proteins, and peptidoglycan synthesis compared with CON-fed pigs. Overall, juvenile Ossabaw swine fed a high-fat, high-fructose, high-cholesterol diet develop obesity and severe microbiota dysbiosis with a proinflammatory signature and a NASH phenotype directly relevant to the pediatric/adolescent and young adult population.

Long-term cathode performance and the microbial communities that develop in microbial fuel cells fed different fermentation endproducts.

PubMed

Kiely, Patrick D; Rader, Geoffrey; Regan, John M; Logan, Bruce E

2011-01-01

To better understand how cathode performance and substrates affected communities that evolved in these reactors over long periods of time, microbial fuel cells were operated for more than 1 year with individual endproducts of lignocellulose fermentation (acetic acid, formic acid, lactic acid, succinic acid, or ethanol). Large variations in reactor performance were primarily due to the specific substrates, with power densities ranging from 835 ± 21 to 62 ± 1mW/m(3). Cathodes performance degraded over time, as shown by an increase in power of up to 26% when the cathode biofilm was removed, and 118% using new cathodes. Communities that developed on the anodes included exoelectrogenic families, such as Rhodobacteraceae, Geobacteraceae, and Peptococcaceae, with the Deltaproteobacteria dominating most reactors. Pelobacter propionicus was the predominant member in reactors fed acetic acid, and it was abundant in several other MFCs. These results provide valuable insights into the effects of long-term MFC operation on reactor performance. Copyright © 2010 Elsevier Ltd. All rights reserved.

The giraffe (Giraffa camelopardalis) rumen microbiome.

PubMed

Roggenbuck, Michael; Sauer, Cathrine; Poulsen, Morten; Bertelsen, Mads F; Sørensen, Søren J

2014-10-01

Recent studies have shown that wild ruminants are sources of previously undescribed microorganisms, knowledge of which can improve our understanding of the complex microbial interactions in the foregut. Here, we investigated the microbial community of seven wild-caught giraffes (Giraffa camelopardalis), three of which were fed natural browse and four were fed Boskos pellets, leafy alfalfa hay, and cut savanna browse, by characterizing the 16S rRNA gene diversity using 454 FLX high-throughput sequencing. The microbial community composition varied according to diet, but differed little between the ruminal fluid and solid fraction. The giraffe rumen contained large levels of the phyla of Firmicutes and Bacteroidetes independent of diet, while Prevotella, Succinclasticium, and Methanobrevibacter accounted for the largest abundant taxonomic assigned genera. However, up to 21% of the generated sequences could not been assigned to any known bacterial phyla, and c. 70% not to genus, revealing that the giraffe rumen hosts a variety of previously undescribed bacteria. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Barley β-glucan improves metabolic condition via short-chain fatty acids produced by gut microbial fermentation in high fat diet fed mice.

PubMed

Miyamoto, Junki; Watanabe, Keita; Taira, Satsuki; Kasubuchi, Mayu; Li, Xuan; Irie, Junichiro; Itoh, Hiroshi; Kimura, Ikuo

2018-01-01

Dietary intake of barley β-glucan (BG) is known to affect energy metabolism. However, its underlying mechanism remains poorly understood because studies have presented inconsistent results, with both positive and negative effects reported in terms of satiety, energy intake, weight loss, and glycemic control. The objective of this study was to clarify the physiological role underlying the metabolic benefits of barley BG using a mouse model of high fat diet (HFD)-induced obesity. Male 4-wk-old C57BL/6J mice were fed an HFD with 20% barley flour containing either high BG (HBG; 2% BG) or low BG (LBG; 0.6% BG) levels under conventional and germ-free (GF) conditions for 12 wks. In addition, mice were fed either an HFD with 5% cellulose (HFC; high fiber cellulose) or 5% barley BG (HFB; high fiber β-glucan) for 12 wks. Then, metabolic parameters, gut microbial compositions, and the production of fecal short-chain fatty acids (SCFAs) were analyzed. The weight gain and fat mass of HBG-fed mice were lower than those of control mice at 16-wk-old. Moreover, the secretion of the gut hormones PYY and GLP-1 increased in HBG-fed mice, thereby reducing food intake and improving insulin sensitivity by changing the gut microbiota and increasing SCFAs (especially, butyrate) under conventional condition. These effects in HBG-fed mice were abolished under GF conditions. Moreover, the HFB diets also increased PYY and GLP-1 secretion, and decreased food intake compared with that in HFC-fed mice. These results suggest that the beneficial metabolic effects of barley BG are primary due to the suppression of appetite and improvement of insulin sensitivity, which are induced by gut hormone secretion promoted via gut microbiota-produced SCFAs.

Effects of alfalfa silage storage structure and roasting corn on ruminal digestion and microbial CP synthesis in lactating dairy cows

USDA-ARS?s Scientific Manuscript database

The objective of this experiment was to determine the effects of unroasted ground shelled corn (GSC) or roasted GSC (RGSC), when fed with alfalfa, ensiled in bag, bunker, or O2-limiting tower silos on ruminal digestion and microbial protein synthesis in lactating dairy cows. The roasted corn was hea...

Different substrates and starter inocula govern microbial community structures in biogas reactors.

PubMed

Satpathy, Preseela; Steinigeweg, Sven; Cypionka, Heribert; Engelen, Bert

2016-01-01

The influence of different starter inocula on the microbial communities in biogas batch reactors fed with fresh maize and maize silage as substrates was investigated. Molecular biological analysis by Denaturing Gradient Gel Electrophoresis (DGGE) of 16S rRNA gene fragments showed that each inoculum bore specific microbial communities with varying predominant phylotypes. Both, bacterial and archaeal DGGE profiles displayed three distinct communities that developed depending on the type of inoculum. Although maize and silage are similar substrates, different communities dominated the lactate-rich silage compared to lactate-free fresh maize. Cluster analysis of DGGE gels showed the communities of the same substrates to be stable with their respective inoculum. Bacteria-specific DGGE analysis revealed a rich diversity with Firmicutes being predominant. The other abundant phylotypes were Bacteroidetes and Synergistetes. Archaea-specific DGGE analysis displayed less diverse community structures, identifying members of the Methanosarcinales as the dominant methanogens present in all the three biogas digesters. In general, the source of inoculum played a significant role in shaping microbial communities. Adaptability of the inoculum to the substrates fed also influenced community compositions which further impacted the rates of biogas production.

Genome-Resolved Meta-Omics Ties Microbial Dynamics to Process Performance in Biotechnology for Thiocyanate Degradation.

PubMed

Kantor, Rose S; Huddy, Robert J; Iyer, Ramsunder; Thomas, Brian C; Brown, Christopher T; Anantharaman, Karthik; Tringe, Susannah; Hettich, Robert L; Harrison, Susan T L; Banfield, Jillian F

2017-03-07

Remediation of industrial wastewater is important for preventing environmental contamination and enabling water reuse. Biological treatment for one industrial contaminant, thiocyanate (SCN - ), relies upon microbial hydrolysis, but this process is sensitive to high loadings. To examine the activity and stability of a microbial community over increasing SCN - loadings, we established and operated a continuous-flow bioreactor fed increasing loadings of SCN - . A second reactor was fed ammonium sulfate to mimic breakdown products of SCN - . Biomass was sampled from both reactors for metagenomics and metaproteomics, yielding a set of genomes for 144 bacteria and one rotifer that constituted the abundant community in both reactors. We analyzed the metabolic potential and temporal dynamics of these organisms across the increasing loadings. In the SCN - reactor, Thiobacillus strains capable of SCN - degradation were highly abundant, whereas the ammonium sulfate reactor contained nitrifiers and heterotrophs capable of nitrate reduction. Key organisms in the SCN - reactor expressed proteins involved in SCN - degradation, sulfur oxidation, carbon fixation, and nitrogen removal. Lower performance at higher loadings was linked to changes in microbial community composition. This work provides an example of how meta-omics can increase our understanding of industrial wastewater treatment and inform iterative process design and development.

Oral Microbial Profile Discriminates Breastfed from Formula-Fed Infants

PubMed Central

Holgerson, Pernilla Lif; Vestman, Nelly Romani; Claesson, Rolf; Öhman, Carina; Domellöf, Magnus; Tanner, Anne CR; Hernell, Olle; Johansson, Ingegerd

2012-01-01

Objectives Little is known about the impact of diet on the oral microbiota of infants although diet is known to affect the gut microbiota. The aims of the present study were to compare the oral microbiota in breastfed and formula-fed infants, and investigate growth inhibition of streptococci by infant-isolated lactobacilli. Subjects and Methods 207 mothers consented to participation of their three-month old infants. 146 (70.5%) infants were exclusively and 38 (18.4%) partially breastfed, and 23 (11.1%) were exclusively formula-fed. Saliva from all infants was cultured for Lactobacillus species, with isolate identifications from 21 infants. Lactobacillus isolates were tested for their ability to supress Streptococcus mutans and Streptococcus sanguinis. Oral swabs from 73 infants were analysed by the Human Oral Microbe Identification Microarray (HOMIM) and by q-PCR for Lactobacilius gasseri. Results Lactobacilli were cultured from 27.8% of exclusively and partially breastfed infants, but not from formula-fed infants. The prevalence of 14 HOMIM detected taxa, and total salivary lactobacilli counts differed by feeding method. Multivariate modelling of HOMIM detected bacteria and possible confounders clustered samples from breastfed infants separately from formula-fed infants. The microbiota of breastfed infants differed based on vaginal or C-section delivery. Isolates of Lactobacillus plantarum, L. gasseri and Lactobacillus vaginalis inhibited growth of the cariogenic S. mutans and the commensal S. sanguinis: L. plantarum > L. gasseri > L. vaginalis. Conclusion The microbiota of the mouth differs between breastfed and formula-fed three-month-old infants. Possible mechanisms for microbial differences observed include species suppression by lactobacilli indigenous to breast milk. PMID:22955450

Community analysis of biofilms on flame-oxidized stainless steel anodes in microbial fuel cells fed with different substrates.

PubMed

Eyiuche, Nweze Julius; Asakawa, Shiho; Yamashita, Takahiro; Ikeguchi, Atsuo; Kitamura, Yutaka; Yokoyama, Hiroshi

2017-06-29

The flame-oxidized stainless steel anode (FO-SSA) is a newly developed electrode that enhances microbial fuel cell (MFC) power generation; however, substrate preference and community structure of the biofilm developed on FO-SSA have not been well characterized. Herein, we investigated the community on FO-SSA using high-throughput sequencing of the 16S rRNA gene fragment in acetate-, starch-, glucose-, and livestock wastewater-fed MFCs. Furthermore, to analyze the effect of the anode material, the acetate-fed community formed on a common carbon-based electrode-carbon-cloth anode (CCA)-was examined for comparison. Substrate type influenced the power output of MFCs using FO-SSA; the highest electricity was generated using acetate as a substrate, followed by peptone, starch and glucose, and wastewater. Intensity of power generation using FO-SSA was related to the abundance of exoelectrogenic genera, namely Geobacter and Desulfuromonas, of the phylum Proteobacteria, which were detected at a higher frequency in acetate-fed communities than in communities fed with other substrates. Lactic acid bacteria (LAB)-Enterococcus and Carnobacterium-were predominant in starch- and glucose-fed communities, respectively. In the wastewater-fed community, members of phylum Planctomycetes were frequently detected (36.2%). Exoelectrogenic genera Geobacter and Desulfuromonas were also detected in glucose-, starch-, and wastewater-fed communities on FO-SSA, but with low frequency (0-3.2%); the lactate produced by Carnobacterium and Enterococcus in glucose- and starch-fed communities might affect exoelectrogenic bacterial growth, resulting in low power output by MFCs fed with these substrates. Furthermore, in the acetate-fed community on FO-SSA, Desulfuromonas was abundant (15.4%) and Geobacter had a minor proportion (0.7%), while in that on CCA, both Geobacter and Desulfuromonas were observed at similar frequencies (6.0-9.8%), indicating that anode material affects exoelectrogenic genus enrichment in anodic biofilm. Anodic community structure was dependent on both substrate and anode material. Although Desulfuromonas spp. are marine microorganisms, they were abundant in the acetate-fed community on FO-SSA, implying the presence of novel non-halophilic and exoelectrogenic species in this genus. Power generation using FO-SSA was positively related to the frequency of exoelectrogenic genera in the anodic community. Predominant LAB in saccharide-fed anodic biofilm caused low abundance of exoelectrogenic genera and consequent low power generation.

Electric energy production from food waste: Microbial fuel cells versus anaerobic digestion.

PubMed

Xin, Xiaodong; Ma, Yingqun; Liu, Yu

2018-05-01

A food waste resourceful process was developed by integrating the ultra-fast hydrolysis and microbial fuel cells (MFCs) for energy and resource recovery. Food waste was first ultra-fast hydrolyzed by fungal mash rich in hydrolytic enzymes in-situ produced from food waste. After which, the separated solids were readily converted to biofertilizer, while the liquid was fed to MFCs for direct electricity generation with a conversion efficiency of 0.245 kWh/kg food waste. It was estimated that about 192.5 million kWh of electricity could be produced from the food waste annually generated in Singapore, together with 74,390 tonnes of dry biofertilizer. Compared to anaerobic digestion, the proposed approach was more environmentally friendly and economically viable in terms of both electricity conversion and process cost. It is expected that this study may lead to the paradigm shift in food waste management towards ultra-fast concurrent recovery of resource and electricity with zero-solid discharge. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ulva biomass as a co-substrate for stable anaerobic digestion of spent coffee grounds in continuous mode.

PubMed

Kim, Jaai; Kim, Hakchan; Lee, Changsoo

2017-10-01

Ulva biomass was evaluated as a co-substrate for anaerobic digestion of spent coffee grounds at varying organic loads (0.7-1.6g chemical oxygen demand (COD)/Ld) and substrate compositions. Co-digestion with Ulva (25%, COD basis) proved beneficial for SCG biomethanation in both terms of process performance and stability. The beneficial effect is much more pronounced at higher organic and hydraulic loads, with the highest COD removal and methane yield being 51.8% and 0.19L/g COD fed, respectively. The reactor microbial community structure changed dynamically during the experiment, and a dominance shift from hydrogenotrophic to aceticlastic methanogens occurred with increase in organic loading rate. Network analysis provides a comprehensive view of the microbial interactions involved in the system and confirms a direct positive correlation between Ulva input and methane productivity. A group of populations, including Methanobacterium- and Methanoculleus-related methanogens, was identified as a possible indicator for monitoring the biomethanation performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of rumen microbial populations in lactating dairy cattle fed diets varying in carbohydrate profiles and Saccharomyces cerevisiae fermentation product.

PubMed

Mullins, C R; Mamedova, L K; Carpenter, A J; Ying, Y; Allen, M S; Yoon, I; Bradford, B J

2013-09-01

The rumen microbial ecosystem is a critical factor that links diets to bovine physiology and productivity; however, information about dietary effects on microbial populations has generally been limited to small numbers of samples and qualitative assessment. To assess whether consistent shifts in microbial populations occur in response to common dietary manipulations in dairy cattle, samples of rumen contents were collected from 2 studies for analysis by quantitative real-time PCR (qPCR). In one study, lactating Holstein cows (n=8) were fed diets in which a nonforage fiber source replaced an increasing proportion of forages and concentrates in a 4×4 Latin square design, and samples of ruminal digesta were collected at 9-h intervals over 3 d at the end of each period. In the second study, lactating Holstein cows (n=15) were fed diets with or without the inclusion of a Saccharomyces cerevisiae fermentation product (SCFP) in a crossover design. In this study, rumen liquid and solid samples were collected during total rumen evacuations before and after feeding in a 42-h period. In total, 146 samples of ruminal digesta were used for microbial DNA isolation and analysis by qPCR. Validated primer sets were used to quantify total bacterial and anaerobic fungal populations as well as 12 well-studied bacterial taxa. The relative abundance of the target populations was similar to those previously reported. No significant treatment effects were observed for any target population. A significant interaction of treatment and dry matter intake was observed, however, for the abundance of Eubacterium ruminantium. Increasing dry matter intake was associated with a quadratic decrease in E. ruminantium populations in control animals but with a quadratic increase in E.ruminantium populations in cows fed SCFP. Analysis of sample time effects revealed that Fibrobacter succinogenes and fungal populations were more abundant postfeeding, whereas Ruminococcus albus tended to be more abundant prefeeding. Seven of the target taxa were more abundant in either the liquid or solid fractions of ruminal digesta. By accounting for the total mass of liquid and solid fractions in the rumen and the relative abundance of total bacteria in each fraction, it was estimated that 92% of total bacteria were found in the solid digesta fraction. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Resistant starch alters gut microbiome and metabolomic profiles concurrent with amelioration of chronic kidney disease in rats

PubMed Central

Kieffer, Dorothy A.; Piccolo, Brian D.; Vaziri, Nosratola D.; Liu, Shuman; Lau, Wei L.; Khazaeli, Mahyar; Nazertehrani, Sohrab; Moore, Mary E.; Marco, Maria L.; Martin, Roy J.

2016-01-01

Patients and animals with chronic kidney disease (CKD) exhibit profound alterations in the gut environment including shifts in microbial composition, increased fecal pH, and increased blood levels of gut microbe-derived metabolites (xenometabolites). The fermentable dietary fiber high amylose maize-resistant starch type 2 (HAMRS2) has been shown to alter the gut milieu and in CKD rat models leads to markedly improved kidney function. The aim of the present study was to identify specific cecal bacteria and cecal, blood, and urinary metabolites that associate with changes in kidney function to identify potential mechanisms involved with CKD amelioration in response to dietary resistant starch. Male Sprague-Dawley rats with adenine-induced CKD were fed a semipurified low-fiber diet or a high-fiber diet [59% (wt/wt) HAMRS2] for 3 wk (n = 9 rats/group). The cecal microbiome was characterized, and cecal contents, serum, and urine metabolites were analyzed. HAMRS2-fed rats displayed decreased cecal pH, decreased microbial diversity, and an increased Bacteroidetes-to-Firmicutes ratio. Several uremic retention solutes were altered in the cecal contents, serum, and urine, many of which had strong correlations with specific gut bacteria abundances, i.e., serum and urine indoxyl sulfate were reduced by 36% and 66%, respectively, in HAMRS2-fed rats and urine p-cresol was reduced by 47% in HAMRS2-fed rats. Outcomes from this study were coincident with improvements in kidney function indexes and amelioration of CKD outcomes previously reported for these rats, suggesting an important role for microbial-derived factors and gut microbe metabolism in regulating host kidney function. PMID:26841824

Resistant starch alters gut microbiome and metabolomic profiles concurrent with amelioration of chronic kidney disease in rats.

PubMed

Kieffer, Dorothy A; Piccolo, Brian D; Vaziri, Nosratola D; Liu, Shuman; Lau, Wei L; Khazaeli, Mahyar; Nazertehrani, Sohrab; Moore, Mary E; Marco, Maria L; Martin, Roy J; Adams, Sean H

2016-05-01

Patients and animals with chronic kidney disease (CKD) exhibit profound alterations in the gut environment including shifts in microbial composition, increased fecal pH, and increased blood levels of gut microbe-derived metabolites (xenometabolites). The fermentable dietary fiber high amylose maize-resistant starch type 2 (HAMRS2) has been shown to alter the gut milieu and in CKD rat models leads to markedly improved kidney function. The aim of the present study was to identify specific cecal bacteria and cecal, blood, and urinary metabolites that associate with changes in kidney function to identify potential mechanisms involved with CKD amelioration in response to dietary resistant starch. Male Sprague-Dawley rats with adenine-induced CKD were fed a semipurified low-fiber diet or a high-fiber diet [59% (wt/wt) HAMRS2] for 3 wk (n = 9 rats/group). The cecal microbiome was characterized, and cecal contents, serum, and urine metabolites were analyzed. HAMRS2-fed rats displayed decreased cecal pH, decreased microbial diversity, and an increased Bacteroidetes-to-Firmicutes ratio. Several uremic retention solutes were altered in the cecal contents, serum, and urine, many of which had strong correlations with specific gut bacteria abundances, i.e., serum and urine indoxyl sulfate were reduced by 36% and 66%, respectively, in HAMRS2-fed rats and urine p-cresol was reduced by 47% in HAMRS2-fed rats. Outcomes from this study were coincident with improvements in kidney function indexes and amelioration of CKD outcomes previously reported for these rats, suggesting an important role for microbial-derived factors and gut microbe metabolism in regulating host kidney function. Copyright © 2016 the American Physiological Society.

Diets high in resistant starch and arabinoxylan modulate digestion processes and SCFA pool size in the large intestine and faecal microbial composition in pigs.

PubMed

Nielsen, Tina S; Lærke, Helle N; Theil, Peter K; Sørensen, Jens F; Saarinen, Markku; Forssten, Sofia; Knudsen, Knud E Bach

2014-12-14

The effects of a high level of dietary fibre (DF) either as arabinoxylan (AX) or resistant starch (RS) on digestion processes, SCFA concentration and pool size in various intestinal segments and on the microbial composition in the faeces were studied in a model experiment with pigs. A total of thirty female pigs (body weight 63.1 (sem 4.4) kg) were fed a low-DF, high-fat Western-style control diet (WSD), an AX-rich diet (AXD) or a RS-rich diet (RSD) for 3 weeks. Diet significantly affected the digestibility of DM, protein, fat, NSP and NSP components, and the arabinose:xylose ratio, as well as the disappearance of NSP and AX in the large intestine. RS was mainly digested in the caecum. AX was digested at a slower rate than RS. The digesta from AXD-fed pigs passed from the ileum to the distal colon more than twice as fast as those from WSD-fed pigs, with those from RSD-fed pigs being intermediate (P< 0.001). AXD feeding resulted in a higher number of Faecalibacterium prausnitzii, Roseburia intestinalis, Blautia coccoides-Eubacterium rectale, Bifidobacterium spp. and Lactobacillus spp. in the faeces sampled at week 3 of the experimental period (P< 0.05). In the caecum, proximal and mid colon, AXD feeding resulted in a 3- to 5-fold higher pool size of butyrate compared with WSD feeding, with the RSD being intermediate (P <0.001). In conclusion, the RSD and AXD differently affected digestion processes compared with the WSD, and the AXD most efficiently shifted the microbial composition towards butyrogenic species in the faeces and increased the large-intestinal butyrate pool size.

Degradation of Potassium Rock by Earthworms and Responses of Bacterial Communities in Its Gut and Surrounding Substrates after Being Fed with Mineral

PubMed Central

Liu, Dianfeng; Lian, Bin; Wang, Bin; Jiang, Guofang

2011-01-01

Background Earthworms are an ecosystem's engineers, contributing to a wide range of nutrient cycling and geochemical processes in the ecosystem. Their activities can increase rates of silicate mineral weathering. Their intestinal microbes usually are thought to be one of the key drivers of mineral degradation mediated by earthworms,but the diversities of the intestinal microorganisms which were relevant with mineral weathering are unclear. Methodology/Principal Findings In this report, we show earthworms' effect on silicate mineral weathering and the responses of bacterial communities in their gut and surrounding substrates after being fed with potassium-bearing rock powder (PBRP). Determination of water-soluble and HNO3-extractable elements indicated some elements such as Al, Fe and Ca were significantly released from mineral upon the digestion of earthworms. The microbial communities in earthworms' gut and the surrounding substrates were investigated by amplified ribosomal DNA restriction analysis (ARDRA) and the results showed a higher bacterial diversity in the guts of the earthworms fed with PBRP and the PBRP after being fed to earthworms. UPGMA dendrogram with unweighted UniFrac analysis, considering only taxa that are present, revealed that earthworms' gut and their surrounding substrate shared similar microbiota. UPGMA dendrogram with weighted UniFrac, considering the relative abundance of microbial lineages, showed the two samples from surrounding substrate and the two samples from earthworms' gut had similarity in microbial community, respectively. Conclusions/Significance Our results indicated earthworms can accelerate degradation of silicate mineral. Earthworms play an important role in ecosystem processe since they not only have some positive effects on soil structure, but also promote nutrient cycling of ecosystem by enhancing the weathering of minerals. PMID:22174903

Kinetics of nitrate and sulfate removal using a mixed microbial culture with or without limited-oxygen fed.

PubMed

Xu, Xi-Jun; Chen, Chuan; Wang, Ai-Jie; Guo, Hong-Liang; Yuan, Ye; Lee, Duu-Jong; Ren, Nan-Qi

2014-07-01

The biological degradation of nitrate and sulfate was investigated using a mixed microbial culture and lactate as the carbon source, with or without limited-oxygen fed. It was found that sulfate reduction was slightly inhibited by nitrate, since after nitrate depletion the sulfate reduction rate increased from 0.37 mg SO4 (2-)/mg VSS d to 0.71 mg SO4 (2-)/mg VSS d, and the maximum rate of sulfate reduction in the presence of nitrate corresponded to 56 % of the non-inhibited sulfate reduction rate determined after nitrate depleted. However, simultaneous but not sequential reduction of both oxy-anions was observed in this study, unlike some literature reports in which sulfate reduction starts only after depletion of nitrate, and this case might be due to the fact that lactate was always kept above the limiting conditions. At limited oxygen, the inhibited effect on sulfate reduction by nitrate was relieved, and the sulfate reduction rate seemed relatively higher than that obtained without limited-oxygen fed, whereas kept almost constant (0.86-0.89 mg SO4 (2-)/mg VSS d) cross the six ROS states. In contrast, nitrate reduction rates decreased substantially with the increase in the initial limited-oxygen fed, showing an inhibited effect on nitrate reduction by oxygen. Kinetic parameters determined for the mixed microbial culture showed that the maximum specific sulfate utilization rate obtained (0.098 ± 0.022 mg SO4 (2-)/(mg VSS h)) was similar to the reported typical value (0.1 mg SO4 (2-)/(mg VSS h)), also indicating a moderate inhibited effect by nitrate.

13C Pathway Analysis for the Role of Formate in Electricity Generation by Shewanella Oneidensis MR-1 Using Lactate in Microbial Fuel Cells

PubMed Central

Luo, Shuai; Guo, Weihua; H. Nealson, Kenneth; Feng, Xueyang; He, Zhen

2016-01-01

Microbial fuel cell (MFC) is a promising technology for direct electricity generation from organics by microorganisms. The type of electron donors fed into MFCs affects the electrical performance, and mechanistic understanding of such effects is important to optimize the MFC performance. In this study, we used a model organism in MFCs, Shewanella oneidensis MR-1, and 13C pathway analysis to investigate the role of formate in electricity generation and the related microbial metabolism. Our results indicated a synergistic effect of formate and lactate on electricity generation, and extra formate addition on the original lactate resulted in more electrical output than using formate or lactate as a sole electron donor. Based on the 13C tracer analysis, we discovered decoupled cell growth and electricity generation in S. oneidensis MR-1 during co-utilization of lactate and formate (i.e., while the lactate was mainly metabolized to support the cell growth, the formate was oxidized to release electrons for higher electricity generation). To our best knowledge, this is the first time that 13C tracer analysis was applied to study microbial metabolism in MFCs and it was demonstrated to be a valuable tool to understand the metabolic pathways affected by electron donors in the selected electrochemically-active microorganisms. PMID:26868848

Novel Large Sulfur Bacteria in the Metagenomes of Groundwater-Fed Chemosynthetic Microbial Mats in the Lake Huron Basin

PubMed Central

Sharrar, Allison M.; Flood, Beverly E.; Bailey, Jake V.; Jones, Daniel S.; Biddanda, Bopaiah A.; Ruberg, Steven A.; Marcus, Daniel N.; Dick, Gregory J.

2017-01-01

Little is known about large sulfur bacteria (LSB) that inhabit sulfidic groundwater seeps in large lakes. To examine how geochemically relevant microbial metabolisms are partitioned among community members, we conducted metagenomic analysis of a chemosynthetic microbial mat in the Isolated Sinkhole, which is in a deep, aphotic environment of Lake Huron. For comparison, we also analyzed a white mat in an artesian fountain that is fed by groundwater similar to Isolated Sinkhole, but that sits in shallow water and is exposed to sunlight. De novo assembly and binning of metagenomic data from these two communities yielded near complete genomes and revealed representatives of two families of LSB. The Isolated Sinkhole community was dominated by novel members of the Beggiatoaceae that are phylogenetically intermediate between known freshwater and marine groups. Several of these Beggiatoaceae had 16S rRNA genes that contained introns previously observed only in marine taxa. The Alpena fountain was dominated by populations closely related to Thiothrix lacustris and an SM1 euryarchaeon known to live symbiotically with Thiothrix spp. The SM1 genomic bin contained evidence of H2-based lithoautotrophy. Genomic bins of both the Thiothrix and Beggiatoaceae contained genes for sulfur oxidation via the rDsr pathway, H2 oxidation via Ni-Fe hydrogenases, and the use of O2 and nitrate as electron acceptors. Mats at both sites also contained Deltaproteobacteria with genes for dissimilatory sulfate reduction (sat, apr, and dsr) and hydrogen oxidation (Ni-Fe hydrogenases). Overall, the microbial mats at the two sites held low-diversity microbial communities, displayed evidence of coupled sulfur cycling, and did not differ largely in their metabolic potentials, despite the environmental differences. These results show that groundwater-fed communities in an artesian fountain and in submerged sinkholes of Lake Huron are a rich source of novel LSB, associated heterotrophic and sulfate-reducing bacteria, and archaea. PMID:28533768

Novel Large Sulfur Bacteria in the Metagenomes of Groundwater-Fed Chemosynthetic Microbial Mats in the Lake Huron Basin.

PubMed

Sharrar, Allison M; Flood, Beverly E; Bailey, Jake V; Jones, Daniel S; Biddanda, Bopaiah A; Ruberg, Steven A; Marcus, Daniel N; Dick, Gregory J

2017-01-01

Little is known about large sulfur bacteria (LSB) that inhabit sulfidic groundwater seeps in large lakes. To examine how geochemically relevant microbial metabolisms are partitioned among community members, we conducted metagenomic analysis of a chemosynthetic microbial mat in the Isolated Sinkhole, which is in a deep, aphotic environment of Lake Huron. For comparison, we also analyzed a white mat in an artesian fountain that is fed by groundwater similar to Isolated Sinkhole, but that sits in shallow water and is exposed to sunlight. De novo assembly and binning of metagenomic data from these two communities yielded near complete genomes and revealed representatives of two families of LSB. The Isolated Sinkhole community was dominated by novel members of the Beggiatoaceae that are phylogenetically intermediate between known freshwater and marine groups. Several of these Beggiatoaceae had 16S rRNA genes that contained introns previously observed only in marine taxa. The Alpena fountain was dominated by populations closely related to Thiothrix lacustris and an SM1 euryarchaeon known to live symbiotically with Thiothrix spp. The SM1 genomic bin contained evidence of H 2 -based lithoautotrophy. Genomic bins of both the Thiothrix and Beggiatoaceae contained genes for sulfur oxidation via the rDsr pathway, H 2 oxidation via Ni-Fe hydrogenases, and the use of O 2 and nitrate as electron acceptors. Mats at both sites also contained Deltaproteobacteria with genes for dissimilatory sulfate reduction ( sat, apr , and dsr ) and hydrogen oxidation (Ni-Fe hydrogenases). Overall, the microbial mats at the two sites held low-diversity microbial communities, displayed evidence of coupled sulfur cycling, and did not differ largely in their metabolic potentials, despite the environmental differences. These results show that groundwater-fed communities in an artesian fountain and in submerged sinkholes of Lake Huron are a rich source of novel LSB, associated heterotrophic and sulfate-reducing bacteria, and archaea.

Fecal microbiome of growing pigs fed a cereal based diet including chicory (Cichorium intybus L.) or ribwort (Plantago lanceolata L.) forage.

PubMed

Dicksved, Johan; Jansson, Janet K; Lindberg, Jan Erik

2015-01-01

The purpose of this study was to investigate how inclusion of chicory forage or ribwort forage in a cereal-based diet influenced the fecal microbial community (microbiome) in newly weaned (35 days of age) piglets. The piglets were fed a cereal-based diet without (B) and with inclusion (80 and 160 g/kg air-dry forage) of vegetative shoots of chicory (C) and leaves of ribwort (R) forage in a 35-day growth trial. Fecal samples were collected at the start (D0), 17 (D17) and 35 (D35) days after weaning and profiles of the microbial consortia were generated using terminal restriction fragment length polymorphism (T-RFLP). 454-FLX pyrosequencing of 16S rRNA gene amplicons was used to analyze the microbial composition in a subset of the samples already analyzed with T-RFLP. The microbial clustering pattern was primarily dependent on age of the pigs, but diet effects could also be observed. Lactobacilli and enterobacteria were more abundant at D0, whereas the genera Streptococcus, Treponema, Clostridium, Clostridiaceae1 and Coprococcus were present in higher abundances at D35. Pigs fed ribwort had an increased abundance of sequences classified as Treponema and a reduction in lactobacilli. However, the abundance of Prevotellaceae increased with age in on both the chicory and the ribwort diet. Moreover, there were significant correlations between the abundance of Bacteroides and the digested amount of galactose, uronic acids and total non-starch polysaccharides, and between the abundance of Bacteroidales and the digested amount of xylose. This study demonstrated that both chicory and ribwort inclusion in the diet of newly weaned pigs influenced the composition of the fecal microbiota and that digestion of specific dietary components was correlated with species composition of the microbiota. Moreover, this study showed that the gut will be exposed to a dramatic shift in the microbial community structure several weeks after weaning.

Fecal microbiome of growing pigs fed a cereal based diet including chicory (Cichorium intybus L.) or ribwort (Plantago lanceolata L.) forage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dicksved, Johan; Jansson, Janet K.; Lindberg, Jan Erik

BACKGROUND: The purpose of this study was to investigate how inclusion of chicory forage or ribwort forage in a cereal-based diet influenced the fecal microbial community (microbiome) in newly weaned (35 days of age) piglets. The piglets were fed a cereal-based diet without (B) and with inclusion (80 and 160 g/kg air-dry forage) of vegetative shoots of chicory (C) and leaves of ribwort (R) forage in a 35-day growth trial. Fecal samples were collected at the start (D0), 17 (D17) and 35 (D35) days after weaning and profiles of the microbial consortia were generated using terminal restriction fragment length polymorphismmore » (T-RFLP). 454-FLX pyrosequencing of 16S rRNA gene amplicons was used to analyze the microbial composition in a subset of the samples already analyzed with T-RFLP. RESULTS: The microbial clustering pattern was primarily dependent on age of the pigs, but diet effects could also be observed. Lactobacilli and enterobacteria were more abundant at D0, whereas the genera Streptococcus, Treponema, Clostridium, Clostridiaceae1 and Coprococcus were present in higher abundances at D35. Pigs fed ribwort had an increased abundance of sequences classified as Treponema and a reduction in lactobacilli. However, the abundance of Prevotellaceae increased with age in on both the chicory and the ribwort diet. Moreover, there were significant correlations between the abundance of Bacteroides and the digested amount of galactose, uronic acids and total non-starch polysaccharides, and between the abundance of Bacteroidales and the digested amount of xylose. CONCLUSION: This study demonstrated that both chicory and ribwort inclusion in the diet of newly weaned pigs influenced the composition of the fecal microbiota and that digestion of specific dietary components was correlated with species composition of the microbiota. Moreover, this study showed that the gut will be exposed to a dramatic shift in the microbial community structure several weeks after weaning.« less

Diet shifts provoke complex and variable changes in the metabolic networks of the ruminal microbiome.

PubMed

Wolff, Sara M; Ellison, Melinda J; Hao, Yue; Cockrum, Rebecca R; Austin, Kathy J; Baraboo, Michael; Burch, Katherine; Lee, Hyuk Jin; Maurer, Taylor; Patil, Rocky; Ravelo, Andrea; Taxis, Tasia M; Truong, Huan; Lamberson, William R; Cammack, Kristi M; Conant, Gavin C

2017-06-08

Grazing mammals rely on their ruminal microbial symbionts to convert plant structural biomass into metabolites they can assimilate. To explore how this complex metabolic system adapts to the host animal's diet, we inferred a microbiome-level metabolic network from shotgun metagenomic data. Using comparative genomics, we then linked this microbial network to that of the host animal using a set of interface metabolites likely to be transferred to the host. When the host sheep were fed a grain-based diet, the induced microbial metabolic network showed several critical differences from those seen on the evolved forage-based diet. Grain-based (e.g., concentrate) diets tend to be dominated by a smaller set of reactions that employ metabolites that are nearer in network space to the host's metabolism. In addition, these reactions are more central in the network and employ substrates with shorter carbon backbones. Despite this apparent lower complexity, the concentrate-associated metabolic networks are actually more dissimilar from each other than are those of forage-fed animals. Because both groups of animals were initially fed on a forage diet, we propose that the diet switch drove the appearance of a number of different microbial networks, including a degenerate network characterized by an inefficient use of dietary nutrients. We used network simulations to show that such disparate networks are not an unexpected result of a diet shift. We argue that network approaches, particularly those that link the microbial network with that of the host, illuminate aspects of the structure of the microbiome not seen from a strictly taxonomic perspective. In particular, different diets induce predictable and significant differences in the enzymes used by the microbiome. Nonetheless, there are clearly a number of microbiomes of differing structure that show similar functional properties. Changes such as a diet shift uncover more of this type of diversity.

Syntrophic interactions between H2-scavenging and anode-respiring bacteria can improve current density in microbial electrochemical cells

EPA Science Inventory

High current density of 10.0-14.6 A/m2 and COD removal up to 96% were obtained in a microbial electrochemical cell (MEC) fed with digestate at hydraulic retention time (HRT) of 4d and 8d. Volatile fatty acids became undetectable in MEC effluent (HRT 8d), except for trivial acetat...

The fate of (13)C-labelled and non-labelled inulin predisposed to large bowel fermentation in rats.

PubMed

Butts, Christine A; Paturi, Gunaranjan; Tavendale, Michael H; Hedderley, Duncan; Stoklosinski, Halina M; Herath, Thanuja D; Rosendale, Douglas; Roy, Nicole C; Monro, John A; Ansell, Juliet

2016-04-01

The fate of stable-isotope (13)C labelled and non-labelled inulin catabolism by the gut microbiota was assessed in a healthy rat model. Sprague-Dawley male rats were randomly assigned to diets containing either cellulose or inulin, and were fed these diets for 3 days. On day (d) 4, rats allocated to the inulin diet received (13)C-labelled inulin. The rats were then fed the respective non-labelled diets (cellulose or inulin) until sampling (d4, d5, d6, d7, d10 and d11). Post feeding of (13)C-labelled substrate, breath analysis showed that (13)C-inulin cleared from the host within a period of 36 hours. Faecal (13)C demonstrated the clearance of inulin from gut with a (13)C excess reaching maximum at 24 hours (d5) and then declining gradually. There were greater variations in caecal organic acid concentrations from d4 to d6, with higher concentrations of acetic, butyric and propionic acids observed in the rats fed inulin compared to those fed cellulose. Inulin influenced caecal microbial glycosidase activity, increased colon crypt depth, and decreased the faecal output and polysaccharide content compared to the cellulose diet. In summary, the presence of inulin in the diet positively influenced large bowel microbial fermentation.

Effects of influent strength on microorganisms in surface flow mesocosm wetlands.

PubMed

Tao, Wendong; Hall, Ken J; Ramey, William

2007-11-01

To choose an appropriate dilution ratio to treat woodwaste leachate without inhibition on heterotrophic bacteria, microbial ATP concentration and the rates of heterotrophic leucine incorporation and acetate uptake were compared across surface flow mesocosm wetlands fed with different strengths of influent. Abundances of protozoa and respiring bacteria were investigated in two mesocosm wetlands to elucidate the effects of influent strength on heterotrophic bacteria. The strongest influent or the raw leachate did not show a significant inhibitory effect on leucine incorporation and acetate uptake. Instead, leucine incorporation rates by bacteria in water, epiphytic biofilm and sediment were higher in mesocosm wetlands fed with a stronger influent. There were significantly more respiring planktonic bacteria (451 x 10(5) mL(-1)) and fewer nanoflagellates (3.8 x 10(3) mL(-1)) in the mesocosm fed with a strong influent, while fewer respiring planktonic bacteria (38.7 x 10(5)mL(-1)) and more nanoflagellates (15.4 x 10(3) mL(-1)) in the mesocosm fed with a weak influent. The majority of the total microbial ATP was attributed to sedimentary bacteria, of which >96% were inactive. Heterotrophic activity and its distribution among water, epiphytic biofilm and sediment in the mesocosm wetlands were affected by availability of bacterial substrates and grazing pressure of nanoflagellates.

Microbial protein synthesis, ruminal digestion, microbial populations, and nitrogen balance in sheep fed diets varying in forage-to-concentrate ratio and type of forage.

PubMed

Ramos, S; Tejido, M L; Martínez, M E; Ranilla, M J; Carro, M D

2009-09-01

Six ruminally and duodenally cannulated sheep were used in a partially replicated 4 x 4 Latin square to evaluate the effects of 4 diets on microbial synthesis, microbial populations, and ruminal digestion. The experimental diets had forage to concentrate ratios (F:C; DM basis) of 70:30 (HF) or 30:70 (HC) with alfalfa hay (A) or grass hay (G) as forage and were designated as HFA, HCA, HFG, and HCG. The concentrate was based on barley, gluten feed, wheat middlings, soybean meal, palmkern meal, wheat, corn, and mineral-vitamin premix in the proportions of 22, 20, 20, 13, 12, 5, 5, and 3%, respectively (as-is basis). Sheep were fed the diets at a daily rate of 56 g/kg of BW(0.75) to minimize feed selection. High-concentrate diets resulted in greater (P < 0.001) total tract apparent OM digestibility compared with HF diets, but no differences were detected in NDF digestibility. Ruminal digestibility of OM, NDF, and ADF was decreased by increasing the proportion of concentrate, but no differences between forages were detected. Compared with sheep fed HF diets, sheep receiving HC diets had less ruminal pH values and acetate proportions, but greater butyrate proportions. No differences among diets were detected in numbers of cellulolytic bacteria, but protozoa numbers were less (P = 0.004) and total bacteria numbers tended (P = 0.08) to be less for HC diets. Carboxymethylcellulase, xylanase, and amylase activities were greater for HC compared with HF diets, with A diets showing greater (P = 0.008) carboxymethylcellulase activities than G diets. Retained N ranged from 28.7 to 37.9% of N intake and was not affected by F:C (P = 0.62) or the type of forage (P = 0.31). Microbial N synthesis and its efficiency was greater (P < 0.001) for HC diets compared with HF diets. The results indicate that concentrates with low cereal content can be included in the diet of sheep up to 70% of the diet without detrimental effects on ruminal activity, microbial synthesis efficiency, and N losses.

Effects of Supplementation of Mulberry (Morus alba) Foliage and Urea-rice Bran as Fermentable Energy and Protein Sources in Sheep Fed Urea-treated Rice Straw Based Diet.

PubMed

Yulistiani, Dwi; Jelan, Z A; Liang, J B; Yaakub, H; Abdullah, N

2015-04-01

A digestibility study was conducted to evaluate the effects of supplementing mulberry foliage and urea rice-bran as a source of fermentable energy and protein to 12 sheep fed diets based on urea-treated rice straw (TRS). The three dietary treatments were: T1, TRS with mulberry; T2, TRS with 50% mulberry replaced with rice bran and urea; and T3, TRS with rice bran and urea. The study was arranged in a completely randomized design with four replications for each treatment. The sheep were fed one of the three diets and the supplements were offered at 1.2% of the body weight (BW) and the TRS was provided ad libitum. There were no differences (p>0.05) among the three treatment groups with respect to dry matter (DM) intake (76.8±4.2 g/kg BW(0.75)) and DM, organic matter (OM), and crude protein (CP) digestibility (55.3±1.22; 69.9±0.85; 46.3±1.65% respectively for DM, OM, and CP). The digestibility of fiber (neutral detergent fiber [NDF] and acid detergent fiber) was significantly lower (p<0.05) for T3 (46.2 and 46.6 respectively) compared to T1 (55.8 and 53.7 respectively) and T2 (54.1 and 52.8 respectively). Nitrogen (N) intake by sheep on diet T3 was significantly (p<0.05) higher than sheep fed diet T1. However, N balance did not differ among the three diets (3.0±0.32 g/d). In contrast, the rumen ammonia (NH3-N) concentrations in sheep fed T2 and T3 were significantly (p<0.05) higher than in sheep fed T1. The NH3-N concentrations for all three diets were above the critical value required for optimum rumen microbial growth and synthesis. Total volatile fatty acid concentrations were highest (p<0.05) in T1 (120.3 mM), whilst the molar proportion of propionic acid was highest in T3 (36.9%). However, the microbial N supply in sheep fed T1 and T3 was similar but was significantly (p<0.05) higher than for sheep fed T2. It was concluded that mulberry foliage is a potential supplement of fermentable energy and protein for sheep fed TRS based diet. The suggested level of supplementation is 1.2% of BW or 32% of the total diet since it resulted in similar effects on the intake of DM, OM, and NDF, digestibility of DM, OM, and CP, N utilization and microbial supply when compared to rice bran and urea supplementation.

Energy utilization, nitrogen balance and microbial protein supply in cattle fed Pennisetum purpureum and condensed tannins.

PubMed

Piñeiro-Vázquez, A T; Canul-Solis, J R; Alayón-Gamboa, J A; Chay-Canul, A J; Ayala-Burgos, A J; Solorio-Sánchez, F J; Aguilar-Pérez, C F; Ku-Vera, J C

2017-02-01

The aim of the experiment was to assess the effect of condensed tannins (CT) on feed intake, dry matter digestibility, nitrogen balance, supply of microbial protein to the small intestine and energy utilization in cattle fed a basal ration of Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight of 295 ± 19 kg were allotted to five treatments consisting of increasing levels of CT (0, 1, 2, 3 and 4% CT/kg DM) in a 5 × 5 Latin square design. Dry matter intake (DMI) was similar (p > 0.05) between treatments containing 0, 1, 2 and 3% of CT/kg DM and it was reduced (p < 0.05) to 4% CT (5.71 kg DM/day) with respect to that observed with 0% CT (6.65 kg DM/day). Nitrogen balance, purine derivatives excretion in urine, microbial protein synthesis and efficiency of synthesis of microbial nitrogen in the rumen were not affected (p ≥ 0.05) by the increase in the levels of condensed tannins in the ration. Energy loss as CH 4 was on average 2.7% of the gross energy consumed daily. Metabolizable energy intake was 49.06 MJ/day in cattle fed low-quality tropical grass with a DMI of 6.27 kg/day. It is concluded that concentrations of CT between 2 and 3% of DM of ration reduced energy loss as CH 4 by 31.3% and 47.6%, respectively, without affecting intakes of dry and organic matter; however, digestibilities of dry and organic matter are negatively affected. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Effects of bacterial direct-fed microbials and yeast on site and extent of digestion, blood chemistry, and subclinical ruminal acidosis in feedlot cattle.

PubMed

Beauchemin, K A; Yang, W Z; Morgavi, D P; Ghorbani, G R; Kautz, W; Leedle, J A Z

2003-06-01

Two studies were conducted to determine whether a bacterial direct-fed microbial (DFM) alone or with yeast could minimize the risk of acidosis and improve feed utilization in feedlot cattle receiving high-concentrate diets. Eight ruminally cannulated steers, previously adapted to a high-concentrate diet, were used in crossover designs to study the effects of DFM on feed intake, ruminal pH, ruminal fermentation, blood characteristics, site and extent of digestion, and microbial protein synthesis. Steers were provided ad libitum access to a diet containing steam-rolled barley, barley silage, and a protein-mineral supplement (87, 8, and 5% on a DM basis, respectively). In Exp. 1, treatments were control vs. the lactic-acid producing bacterium Enterococcus faecium EF212 (EF; 6 x 10(9) cfu/d). In Exp. 2, treatments were control vs EF (6 x 10(9) cfu/d) and yeast (Saccharomyces cerevisiae; 6 x 10(9) cfu/d). Supplementing feedlot cattle diets with EF in Exp. 1 increased (P < 0.05) propionate and (P < 0.05) decreased butyrate concentrations, decreased the nadir of ruminal pH (P < 0.05), enhanced the flow of feed N (P < 0.10) to the duodenum but reduced that of microbial N (P < 0.10), reduced (P < 0.10) intestinal digestion of NDF, and increased (P < 0.10) fecal coliform numbers. Other than the increase in propionate concentrations that signify an increase in energy precursors for growth, the other metabolic changes were generally considered to be undesirable. In Exp. 2, providing EF together with yeast abolished most of these undesirable effects. Combining EF with yeast increased the DM digestion of corn grain incubated in sacco, but there were no effects on altering the site or extent of nutrient digestion. The diets used in this study were highly fermentable, and the incidence of subclinical ruminal acidosis, defined as steers with ruminal pH below 5.5 for prolonged periods of time, was high. Supplementing the diet with EF, with or without yeast, had limited effects on reducing ruminal acidosis. It seems that cattle adapted to high-grain diets are able to maintain relatively high feed intake and high fiber digestion despite low ruminal pH. The Enterococcus faecium bacterium and yeast used in this study were of limited value for feedlot cattle already adapted to high-grain diets.

Effects of dietary cooked navy bean on the fecal microbiome of healthy companion dogs.

PubMed

Kerr, Katherine R; Forster, Genevieve; Dowd, Scot E; Ryan, Elizabeth P; Swanson, Kelly S

2013-01-01

Cooked bean powders are a promising novel protein and fiber source for dogs, which have demonstrated potential to alter microbial composition and function for chronic disease control and prevention. This study aimed to determine the impact of cooked navy bean powder fed as a staple food ingredient on the fecal microbiome of healthy adult pet dogs. Fecal samples from healthy dogs prior to dietary control and after 4 wk of dietary treatment with macro- and micronutrient matched diets containing either 0 or 25% cooked navy beans (n = 11 and n = 10, respectively) were analyzed by 454-pyrosequencing of the 16S rRNA gene. There were few differences between dogs fed the control and navy bean diets after 4 wk of treatment. These data indicate that there were no major effects of navy bean inclusion on microbial populations. However, significant differences due to dietary intervention onto both research diets were observed (i.e., microbial populations at baseline versus 4 wk of intervention with 0 or 25% navy bean diets). After 4 wk of dietary intervention on either control or navy bean diet, the Phylum Firmicutes was increased and the Phyla Actinobacteria and Fusobacteria were decreased compared to baseline. No negative alterations of microbial populations occurred following cooked navy bean intake in dogs, indicating that bean powders may be a viable protein and fiber source for commercial pet foods. The highly variable microbial populations observed in these healthy adult pet dogs at baseline is one potential reason for the difficulty to detect alterations in microbial populations following dietary changes. Given the potential physiological benefits of bean intake in humans and dogs, further evaluation of the impacts of cooked navy bean intake on fecal microbial populations with higher power or more sensitive methods are warranted.

Effects of forage:concentrate ratio and forage type on apparent digestibility, ruminal fermentation, and microbial growth in goats.

PubMed

Cantalapiedra-Hijar, G; Yáñez-Ruiz, D R; Martín-García, A I; Molina-Alcaide, E

2009-02-01

The effects of forage type and forage:concentrate ratio (F:C) on apparent nutrient digestibility, ruminal fermentation, and microbial growth were investigated in goats. A comparison between liquid (LAB) and solid (SAB)-associated bacteria to estimate microbial N flow (MNF) from urinary purine derivative excretion was also examined. Treatments were a 2 x 2 factorial arrangement of forage type (grass hay vs. alfalfa hay) and high vs. low F:C (70:30 and 30:70, respectively). Four ruminally cannulated goats were fed, at maintenance intake, 4 experimental diets according to a 4 x 4 Latin square design. High-concentrate diets resulted in greater (P < 0.001) nutrient digestibility except for ADF. However, CP digestibility increased (P < 0.001) only for the high-concentrate diets including grass hay. Likewise, N retention, ruminal NH(3)-N concentration, and urinary excretion of purine derivatives increased (P < 0.05) with increasing concentrate in animals fed diets based on grass hay (0.23 vs. 0.13 g of retained N/g of digested N, 30.1 vs. 12.9 mg of NH(3)-N/100 mL, and 11.5 vs. 8.40 mmol/d, respectively), but not (P > 0.05) when diets included alfalfa hay. Total protozoa numbers and holotricha proportion were greater and less (P < 0.001), respectively, in high- than in low-concentrate diets. The F:C affected (P < 0.001) ruminal pH but not total VFA concentration (P = 0.12). Ammonia-N concentration was similar (P = 0.13) over time, whereas pH, VFA concentration, and protozoa numbers differed (P < 0.001) among diets. Estimated MNF was strongly influenced by using either the purine bases:N ratio obtained in our experimental conditions or values reported in the literature for small ruminants. There was a F:C effect (P = 0.006) on MNF estimated from LAB but not from SAB. The effect of F:C shifting from 70:30 to 30:70 in goat diets depends on the type of forage used. The MNF measured in goats fed different diets was influenced by the bacterial pellet (LAB or SAB). In addition, the purine bases:N ratio values found were different from those reported in the literature, which underlines the need for these variables to be analyzed directly in pellets isolated from specific animals and experimental conditions.

Effect of treating alfalfa silage with pistachio by-products extract on Saanen dairy goats performance and microbial nitrogen synthesis.

PubMed

Mokhtarpour, A; Naserian, A A; Pourmollae, F; Ghaffari, M H

2016-08-01

A lactation experiment was conducted to determine the influence of addition of pistachio by-products extract (PBE) to alfalfa silage (AS) on performance, rumen fermentation, milk yield and composition, and microbial nitrogen synthesis. Eight multiparous dairy goats (1.8 ± 0.25 kg of milk yield) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments to compare two types of AS (supplemented with or without PBE) with two levels of dietary crude protein (14% vs. 16% CP). Dietary treatments were (i) AS with 14% CP of DM diet without PBE (14%CP-PBE), (ii) AS with 14% CP of DM diet with PBE (14%CP + PBE), (iii) AS with 16% CP of DM diet without PBE (16%CP-PBE) and (iv) AS with 16% CP of DM diet with PBE (16%CP + PBE). PBE was sprayed on fresh alfalfa at a ratio of 500 ml/kg alfalfa DM to get the final concentration of 1% tannin as tannic acid equivalent on DM basis. Intake of CP was greater (p < 0.01) in goats fed 16% CP diets than those fed 14% CP diets, regardless of PBE supplementation. Supplementation of PBE tended to decrease (p = 0.09) rumen NH3 -N concentration regardless of the level of CP in the diet. Supplementation of PBE tended (p = 0.09) to decrease total purine derivatives regardless of the level of CP in the diet with no significant change in microbial nitrogen supply. Efficiency of microbial nitrogen synthesis (EMNS) had a tendency (p = 0.07) to decrease in PBE supplemented diets. There was also a tendency (p = 0.10) for more EMNS in 14% CP fed goats than those fed 16% CP diets. Therefore, AS supplemented with PBE may lead to less concentration of ruminal NH3 -N because of decreased degradation of CP by rumen micro-organisms in response to pistachio by-products tannins. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

Coating-type three-dimensional acetate-driven microbial fuel cells.

PubMed

Yu, Jin; Tang, Yulan

2015-08-01

This study uses sodium acetate as fuel to construct bioelectricity in coating-type three-dimensional microbial fuel cells anode. The coating-type three-dimensional anode was constructed using iron net as structural support, adhering a layer of carbon felt as primary coating and using carbon powder and 30% PTFE solution mixture as coating. The efficiency of electricity production and wastewater treatment were analyzed for the three-dimensional acetate-fed (C2H3NaO2) microbial fuel cells with the various ratio of the coating mixture. The results showed that the efficiency of electricity production was significantly improved when using the homemade coating-type microbial fuel cells anode compared with the one without coating on the iron net, which the apparent internal resistance was decreased by 59.4% and the maximum power density was increased by 1.5 times. It was found the electricity production was greatly influenced by the ratio of the carbon powder and PTFE in the coating. The electricity production was the highest with apparent internal resistance of 190 Ω, and maximum power density of 5189.4 mW m(-3) when 750 mg of carbon powder and 10 ml of PTFE (i.e., ratio 75:1) was used in the coating. With the efficiency of electricity production, wide distribution and low cost of the raw materials, the homemade acetate-fed microbial fuel cells provides a valuable reference to the development of the composition microbial fuel cell anode production. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Description of development of rumen ecosystem by PCR assay in milk-fed, weaned and finished lambs in an intensive fattening system.

PubMed

Belanche, A; Balcells, J; de la Fuente, G; Yañez-Ruíz, D R; Fondevila, M; Calleja, L

2010-10-01

This study examined the reticulo-rumen characteristics of the microbial community and its fermentative characteristics in milk-fed, at weaning and finished lambs in a conventional fattening system. Five lambs were assigned to each of three groups: milk-fed lambs slaughtered at 30 days (T30), weaned lambs slaughtered at 45 days (T45) and 'finished lambs' slaughtered at 90 days (T90). At slaughter, rumen size, fermentation parameters (pH, volatile fatty acids and microbial enzyme activity) and protozoal counts were recorded. Quantitative PCR was used to quantify the genes encoding 16S and 18S ribosomal DNA of the rumen bacterial and protozoal populations, respectively, and the sequential colonization of the rumen by cellulolytic (Ruminococcus albus, Ruminococcus flavefaciens) and amylolytic (Prevotella ruminicola, Streptococcus bovis) bacteria, and protozoa (Entodinium sp.). Denaturing gradient gel electrophoresis was used to study the development of rumen microbiota biodiversity. Intake of solid food before weaning caused a significant increase in rumen weight (p < 0.0001) and bacterial DNA (p < 0.05) and volatile fatty acid analysis concentration (p < 0.01), whereas pH declined. In milk-fed lambs, cellulolytic bacteria were evident after 30 days. Thereafter, in the 45-day and 90-day groups, the proportions of R. flavefaciens decreased and R. albus increased. Amylolytic bacteria were present in milk-fed lambs; the proportion of P. ruminicola increased in fattening lambs and S. bovis was the least abundant species. Protozoal concentrations were irregular; milk-fed lambs had a significant number of protozoa species from Entodinium and subfamily Isotrichiidae, but they disappeared at weaning. Lamb rumen were refaunated in some individuals at 90 days (Entodinium and subfamily Diplodiniinae spp.), although individual concentrations were variable. © 2009 Blackwell Verlag GmbH.

Changes in intestinal immunity, gut microbiota, and expression of energy metabolism-related genes explain adenoma growth in bilberry and cloudberry-fed ApcMin mice.

PubMed

Päivärinta, Essi; Niku, Mikael; Maukonen, Johanna; Storvik, Markus; Heiman-Lindh, Anu; Saarela, Maria; Pajari, Anne-Maria; Mutanen, Marja

2016-11-01

We showed previously that ellagitannin-rich cloudberries and anthocyanin-rich bilberries reduce the number of intestinal adenomas in multiple intestinal neoplasia/+ (Apc Min ) mice. We also found that cloudberries decreased the size of adenomas, whereas bilberries increased it. Here we hypothesized that the difference in adenoma growth could be explained by dissimilar effects of the berries on intestinal immune responses and gut microbiota, potentially driven by the distinct polyphenol compositions of the 2 berries. Our objectives were to investigate lymphocyte subtypes and the predominant cecal bacterial diversity in mice fed with bilberries and cloudberries, and to analyze global gene expression profiles in the intestinal mucosa. Immunostainings of CD3 + T lymphocytes, FoxP3 + regulatory T lymphocytes, and CD45R + B lymphocytes revealed a smaller ratio of intraepithelial to all mucosal CD3 + T lymphocytes in the cloudberry-fed mice compared with controls, suggesting an attenuation of inflammation. Bilberry feeding induced no changes in the density of any of the lymphocyte subtypes. The predominant bacterial diversity in cecal contents, analyzed using polymerase chain reaction-denaturating gradient gel electrophoresis, was higher in the bilberry group than in the control or cloudberry groups. The microbial profiles of cloudberry-fed mice clustered together and were associated with small adenoma size. Pathway analyses of gene expression data showed that cloudberry down-regulated and bilberry up-regulated the expression of energy metabolism-related genes in the intestinal mucosa. In conclusion, attenuation of intestinal inflammation, changes in microbial profiles, and down-regulation of mucosal energy metabolism may account for the smaller adenoma size in cloudberry-fed mice in comparison to bilberry-fed mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Genome-Resolved Meta-Omics Ties Microbial Dynamics to Process Performance in Biotechnology for Thiocyanate Degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kantor, Rose S.; Huddy, Robert J.; Iyer, Ramsunder

Remediation of industrial wastewater is important for preventing environmental contamination and allowing water reuse. Biological treatment for one industrial contaminant, thiocyanate (SCN - ), relies upon microbial hydrolysis, but this process is sensitive to high loadings. To examine the activity and stability of a microbial community over increasing SCN - loadings, we established and operated a continuous-flow bioreactor fed increasing loadings of SCN - . A second reactor was fed ammonium sulfate to mimic breakdown products of SCN - . Biomass was sampled from both reactors for metagenomics and metaproteomics, yielding a set of genomes for 144 bacteria and onemore » rotifer that constituted the abundant community in both reactors. We analyzed the metabolic potential and temporal dynamics of these organisms across the increasing loadings. In the SCN - reactor, Thiobacillus strains capable of SCN - degradation were highly abundant, whereas the ammonium sulfate reactor contained nitrifiers and heterotrophs capable of nitrate reduction. Key organisms in the SCN - reactor expressed proteins involved in SCN - degradation, sulfur oxidation, carbon fixation, and nitrogen removal. Lower performance at higher loadings was linked to changes in microbial community composition. This work provides an example of how meta-omics can increase our understanding of industrial wastewater treatment and inform iterative process design and development.« less

Electricity and H2 generation from hemicellulose by sequential fermentation and microbial fuel/electrolysis cell

NASA Astrophysics Data System (ADS)

Yan, Di; Yang, Xuewei; Yuan, Wenqiao

2015-09-01

Electricity and hydrogen generation by bacteria Geobacter sulfurreducens in a dual-chamber microbial fuel/electrolysis cell following the fermentation of hemicellulose by bacteria Moorella thermoacetica was investigated. Experimental results showed that 10 g l-1 xylose under 60 °C was appropriate for the fermentation of xylose by M. thermoacetica, yielding 0.87 g-acetic acid per gram of xylose consumed. Corncob hydrolysate could also be fermented to produce acetic acid, but with lower yield (0.74 g-acid per g-xylose). The broths of xylose and corncob hydrolysate fermented by M. thermoacetica containing acetic acid were fed to G. sulfurreducens in a dual-chamber microbial fuel/electrolysis cell for electricity and hydrogen generation. The highest open-circuit cell voltages generated were 802 and 745 mV, and hydrogen yields were 41.7 and 23.3 mmol per mol-acetate, in xylose and corncob hydrolysate fermentation broth media, respectively. The internal resistance of the microbial fuel/electrolysis cell fed with corncob hydrolysate fermentation broth (3472 Ω) was much higher than that with xylose fermentation broth (1993 Ω) or sodium acetate medium (467 Ω), which was believed to be the main cause of the variation in hydrogen yield of the three feeding media.

Genome-Resolved Meta-Omics Ties Microbial Dynamics to Process Performance in Biotechnology for Thiocyanate Degradation

DOE PAGES

Kantor, Rose S.; Huddy, Robert J.; Iyer, Ramsunder; ...

2017-01-31

Remediation of industrial wastewater is important for preventing environmental contamination and allowing water reuse. Biological treatment for one industrial contaminant, thiocyanate (SCN - ), relies upon microbial hydrolysis, but this process is sensitive to high loadings. To examine the activity and stability of a microbial community over increasing SCN - loadings, we established and operated a continuous-flow bioreactor fed increasing loadings of SCN - . A second reactor was fed ammonium sulfate to mimic breakdown products of SCN - . Biomass was sampled from both reactors for metagenomics and metaproteomics, yielding a set of genomes for 144 bacteria and onemore » rotifer that constituted the abundant community in both reactors. We analyzed the metabolic potential and temporal dynamics of these organisms across the increasing loadings. In the SCN - reactor, Thiobacillus strains capable of SCN - degradation were highly abundant, whereas the ammonium sulfate reactor contained nitrifiers and heterotrophs capable of nitrate reduction. Key organisms in the SCN - reactor expressed proteins involved in SCN - degradation, sulfur oxidation, carbon fixation, and nitrogen removal. Lower performance at higher loadings was linked to changes in microbial community composition. This work provides an example of how meta-omics can increase our understanding of industrial wastewater treatment and inform iterative process design and development.« less

Escherichia coli O26 in feedlot cattle: fecal prevalence, isolation, characterization, and effects of an E. coli O157 vaccine and a direct-fed microbial.

PubMed

Paddock, Zac D; Renter, David G; Cull, Charley A; Shi, Xiarong; Bai, Jianfa; Nagaraja, Tiruvoor G

2014-03-01

Escherichia coli O26 is second only to O157 in causing foodborne, Shiga toxin-producing E. coli (STEC) infections. Our objectives were to determine fecal prevalence and characteristics of E. coli O26 in commercial feedlot cattle (17,148) that were enrolled in a study to evaluate an E. coli O157:H7 siderophore receptor and porin (SRP(®)) vaccine (VAC) and a direct-fed microbial (DFM; 10(6) colony-forming units [CFU]/animal/day of Lactobacillus acidophilus and 10(9) CFU/animal/day of Propionibacterium freudenreichii). Cattle were randomly allocated to 40 pens within 10 complete blocks; pens were randomly assigned to control, VAC, DFM, or VAC+DFM treatments. Vaccine was administered on days 0 and 21, and DFM was fed throughout the study. Pen-floor fecal samples (30/pen) were collected weekly for the last 4 study weeks. Samples were enriched in E. coli broth and subjected to a multiplex polymerase chain reaction (PCR) designed to detect O26-specific wzx gene and four major virulence genes (stx1, stx2, eae, and ehxA) and to a culture-based procedure that involved immunomagnetic separation and plating on MacConkey agar. Ten presumptive E. coli colonies were randomly picked, pooled, and tested by the multiplex PCR. Pooled colonies positive for O26 serogroup were streaked on sorbose MacConkey agar, and 10 randomly picked colonies per sample were tested individually by the multiplex PCR. The overall prevalence of E. coli O26 was higher (p<0.001) by the culture-based method compared to the PCR assay (22.7 versus 10.5%). The interventions (VAC and or DFM) had no impact on fecal shedding of O26. Serogroup O26 was recovered in pure culture from 23.9% (260 of 1089) of O26 PCR-positive pooled colonies. Only 7 of the 260 isolates were positive for the stx gene and 90.1% of the isolates possessed an eaeβ gene that codes for intimin subtype β, but not the bfpA gene, which codes for bundle-forming pilus. Therefore, the majority of the O26 recovered from feedlot cattle feces was atypical enteropathogenic E. coli, and not STEC.

Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact.

PubMed

Gordon, M E; Edwards, M S; Sweeney, C R; Jerina, M L

2013-08-01

The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeast, DFM, and Yucca schidigera extract. Ten horses were fed the 2 experimental diets during two 42-d periods in a crossover design. Total fecal and urine collection occurred during the last 14 d of each period. Results indicate no significant differences between Cu, Zn, Mn, and Co concentrations excreted via urine (P > 0.05) due to dietary treatment. There was no difference between fecal Cu and Mn concentrations (P > 0.05) based on diet consumed. Mean fecal Zn and Co concentrations excreted by horses consuming ADD were greater than CTRL (P < 0.003). Differences due to diet were found for selenium fecal (P < 0.0001) and urine (P < 0.0001) excretions, with decreased concentrations found for horses consuming organic selenium yeast (ADD). In contrast, fecal K (%) was greater (P = 0.0421) for horses consuming ADD, whereas concentrations of fecal solids, total N, ammonia N, P, total ammonia, and fecal output did not differ between dietary treatments (P > 0.05). In feces stockpiled to simulate a crude composting method, no differences (P > 0.05) due to diet were detected for particle size, temperature, moisture, OM, total N, P, phosphate, K, moisture, potash, or ammonia N (P > 0.05). Although no difference (P = 0.2737) in feces stockpile temperature due to diet was found, temperature differences over time were documented (P < 0.0001). In conclusion, the addition of certain chelated mineral sources, organic Se yeast, DFM, and Yucca schidigera extract did not decrease most nutrient concentrations excreted. Horses consuming organic selenium as part of the additive diet had lower fecal and urine Se concentrations, as well as greater fecal K concentrations.

Fecal shedding of non-O157 serogroups of Shiga toxin-producing Escherichia coli in feedlot cattle vaccinated with an Escherichia coli O157:H7 SRP vaccine or fed a Lactobacillus-based direct-fed microbial.

PubMed

Cernicchiaro, N; Renter, D G; Cull, C A; Paddock, Z D; Shi, X; Nagaraja, T G

2014-05-01

The objectives of this study were to determine whether fecal shedding of non-O157 Shiga toxin-producing Escherichia coli (STEC) in feedlot cattle was affected by the use of an E. coli O157:H7 vaccine or a direct-fed microbial (DFM) and whether the shedding of a particular non-O157 STEC serogroup within feces was associated with shedding of O157 or other non-O157 STEC serogroups. A total of 17,148 cattle in 40 pens were randomized to receive one, both, or neither (control) of the two interventions: a vaccine based on the siderophore receptor and porin proteins (E. coli SRP vaccine, two doses) and a DFM product (low-dose Bovamine). Fresh fecal samples (30 samples per pen) were collected weekly from pen floors for four consecutive weeks beginning approximately 56 days after study allocation. DNA extracted from enriched samples was tested for STEC O157 and non-O157 serogroups O26, O45, O103, O111, O121, and O145 and for four major virulence genes (stx1, stx2, eae, and ehxA) using an 11-gene multiplex PCR assay. Generalized linear mixed models were used to analyze the effects of treatments and make within-sample comparisons of the presence of O-serogroup-specific genes. Results of cumulative prevalence measures indicated that O157 (14.6%), O26 (10.5%), and O103 (10.3%) were the most prevalent STEC O serogroups. However, the vaccine, DFM, or both had no significant effect (P > 0.05) on fecal prevalence of the six non-O157 STEC serogroups in feedlot cattle. Within-sample comparisons of the presence of STEC serogroup-specific genes indicated that fecal shedding of E. coli O157 in cattle was associated with an increased probability (P < 0.05) of fecal shedding of STEC O26, O45, O103, and O121. Our study revealed that neither the E. coli O157:H7 vaccine, which reduced STEC O157 fecal shedding, nor the DFM significantly affected fecal shedding of non-O157 STEC serogroups, despite the fact that the most prevalent non-O157 STEC serogroups tended to occur concurrently with O157 STEC strains within fecal samples.

Illumina MiSeq sequencing reveals microbial community in HA process for dyeing wastewater treatment fed with different co-substrates.

PubMed

Xie, Xuehui; Liu, Na; Ping, Jing; Zhang, Qingyun; Zheng, Xiulin; Liu, Jianshe

2018-06-01

In present study, a hydrolysis acidification (HA) reactor was used for simulated dyeing wastewater treatment. Co-substrates included starch, glucose, sucrose, yeast extract (YE) and peptone were fed sequentially into the HA reactor to enhance the HA process effects. The performance of the HA reactor and the microbial community structure in HA process were investigated under different co-substrates conditions. Results showed that different co-substrates had different influences on the performance of HA reactor. The highest decolorization (50.64%) and COD removal rate (60.73%) of the HA reactor were obtained when sucrose was as the co-substrate. And it found that carbon co-substrates starch, glucose and sucrose exhibited better decolorization and higher COD removal efficiency of the HA reactor than the nitrogen co-substrates YE and peptone. Microbial community structure in the HA process was analyzed by Illumina MiSeq sequencing. Results revealed different co-substrates had different influences on the community structure and microbial diversity in HA process. It was considered that sucrose could enrich the species such as Raoultella, Desulfovibrio, Tolumonas, Clostridium, which might be capable of degrading the dyes. Sucrose was considered to be the best co-substrate of enhancing the HA reactor's performance in this study. This work would provide deep insight into the influence of many different co-substrates on HA reactor performance and microbial communities in HA process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cellulose digestion in primitive hexapods: Effect of ingested antibiotics on gut microbial populations and gut cellulase levels in the firebrat,Thermobia domestica (Zygentoma, Lepismatidae).

PubMed

Treves, D S; Martin, M M

1994-08-01

Antibiotic feeding studies were conducted on the firebrat,Thermobia domestica (Zygentoma, Lepismatidae) to determine if the insect's gut cellulases were of insect or microbial origin. Firebrats were fed diets containing either nystatin, metronidazole, streptomycin, tetracycline, or an antibiotic cocktail consisting of all four antibiotics, and then their gut microbial populations and gut cellulase levels were monitored and compared with the gut microbial populations and gut cellulase levels in firebrats feeding on antibiotic-free diets. Each antibiotic significantly reduced the firebrat's gut micro-flora. Nystatin reduced the firebrat's viable gut fungi by 89%. Tetracycline and the antibiotic cocktail reduced the firebrat's viable gut bacteria by 81% and 67%, respectively, and metronidazole, streptomycin, tetracycline, and the antibiotic cocktail reduced the firebrat's total gut flora by 35%, 32%, 55%, and 64%, respectively. Although antibiotics significantly reduced the firebrat's viable and total gut flora, gut cellulase levels in firebrats fed antibiotics were not significantly different from those in firebrats on an antibiotic-free diet. Furthermore, microbial populations in the firebrat's gut decreased significantly over time, even in firebrats feeding on the antibiotic-free diet, without corresponding decreases in gut cellulase levels. Based on this evidence, we conclude that the gut cellulases of firebrats are of insect origin. This conclusion implies that symbiont-independent cellulose digestion is a primitive trait in insects and that symbiont-mediated cellulose digestion is a derived condition.

Fate and toxicity of aircraft deicing fluid additives through anaerobic digestion.

PubMed

Gruden, C L; Dow, S M; Hernandez, M T

2001-01-01

Benzotriazole derivatives are widely used corrosion inhibitors and their fate during wastewater treatment processes is unknown. The purpose of this research was to study the toxic effects and fate of the two commercially significant benzotriazole isomers used in aircraft deicing fluids (4-, and 5-, methylbenzotriazole [MeBT]) during anaerobic digestion. Experiments were executed in microcosms using mesophilic anaerobic biomass co-digesting wastewater sludge and propylene glycol. Sorption of MeBT to digesting solids could be approximated with a Freundlich model, and no anaerobic breakdown of either MeBT isomer was detected. Digesters fed more than 300 mg/L MeBT responded with a significant decrease in methanogenic microbial activity and volatile solids production and a concomitant increase in accumulation of volatile fatty acids. Direct microscopic measurements using fluorescent phylogenetic probes applied to digesting biomass revealed that members of both Archaea and Bacteria domains were sensitive to MeBT. Granular activated carbon (GAC) (volatile solids: GAC = 10%) reduced the apparent toxic effects of MeBT; GAC addition nearly restored the baseline activity of digesters fed MeBT (500 to 1000 mg/L).

Barley β-glucan improves metabolic condition via short-chain fatty acids produced by gut microbial fermentation in high fat diet fed mice

PubMed Central

Taira, Satsuki; Kasubuchi, Mayu; Li, Xuan; Irie, Junichiro; Itoh, Hiroshi

2018-01-01

Dietary intake of barley β-glucan (BG) is known to affect energy metabolism. However, its underlying mechanism remains poorly understood because studies have presented inconsistent results, with both positive and negative effects reported in terms of satiety, energy intake, weight loss, and glycemic control. The objective of this study was to clarify the physiological role underlying the metabolic benefits of barley BG using a mouse model of high fat diet (HFD)-induced obesity. Male 4-wk-old C57BL/6J mice were fed an HFD with 20% barley flour containing either high BG (HBG; 2% BG) or low BG (LBG; 0.6% BG) levels under conventional and germ-free (GF) conditions for 12 wks. In addition, mice were fed either an HFD with 5% cellulose (HFC; high fiber cellulose) or 5% barley BG (HFB; high fiber β-glucan) for 12 wks. Then, metabolic parameters, gut microbial compositions, and the production of fecal short-chain fatty acids (SCFAs) were analyzed. The weight gain and fat mass of HBG-fed mice were lower than those of control mice at 16-wk-old. Moreover, the secretion of the gut hormones PYY and GLP-1 increased in HBG-fed mice, thereby reducing food intake and improving insulin sensitivity by changing the gut microbiota and increasing SCFAs (especially, butyrate) under conventional condition. These effects in HBG-fed mice were abolished under GF conditions. Moreover, the HFB diets also increased PYY and GLP-1 secretion, and decreased food intake compared with that in HFC-fed mice. These results suggest that the beneficial metabolic effects of barley BG are primary due to the suppression of appetite and improvement of insulin sensitivity, which are induced by gut hormone secretion promoted via gut microbiota-produced SCFAs. PMID:29698465

Effect of Propionibacterium acidipropionici P169 on the rumen and faecal microbiota of beef cattle fed a maize-based finishing diet.

PubMed

Azad, E; Narvaez, N; Derakhshani, H; Allazeh, A Y; Wang, Y; McAllister, T A; Khafipour, E

2017-10-13

Direct fed microbial supplementation with lactic acid utilising bacteria (i.e. Propionibacterium acidipropionici P169) has been shown to alleviate the severity of subacute ruminal acidosis in high-grain fed beef cattle. This study was carried out to explore the impact of P169 supplementation on modulating rumen and hindgut microbiota of high-grain fed steers. Seven ruminally-canulated high-grain fed steers were randomly assigned to two treatment groups: control diet (n=3) and the same diet supplemented with P169 added at a rate of 1×10 11 cfu/head/d (n=4). Samples were collected every 28 days for a 101 d period (5 time points) and subjected to qPCR quantification of P169 and high-throughput sequencing of bacterial V4 16S rRNA genes. Ruminal abundance of P169 was maintained at elevated levels (P=0.03) both in liquid and solid fractions post supplementation. Concomitant with decreased proportion of amylolytic (such as Prevotella) and key lactate-utilisers (such as Veillonellaceae and Megasphaera), the proportions of cellulolytic bacterial lineages (such as Ruminococcaceae, Lachnospiraceae, Clostridiaceae, and Christensenellaceae) were enriched in the rumen microbiota of P169-supplemented steers. These, coupled with elevated molar proportions of branched-chain fatty acids and increased concentration of ammonia in the rumen content of P169-supplemented steers, indicated an improved state of fibrolytic and proteolytic activity in response to P169 supplementation. Further, exploring the hindgut microbiota of P169-supplemented steers revealed enrichment of major amylolytic bacterial lineages, such as Prevotella, Blautia, and Succinivibrionaceae, which might be indicative of an increased availability of carbohydrates in the hindgut ecosystem following P169 supplementation. Collectively, the present study provides insights into the microbiota dynamics that underlie the P169-associated shifts in the rumen fermentation profile of high-grain fed steers.

Evaluation and Selection of Bacillus Species Based on Enzyme Production, Antimicrobial Activity, and Biofilm Synthesis as Direct-Fed Microbial Candidates for Poultry

PubMed Central

Latorre, Juan D.; Hernandez-Velasco, Xochitl; Wolfenden, Ross E.; Vicente, Jose L.; Wolfenden, Amanda D.; Menconi, Anita; Bielke, Lisa R.; Hargis, Billy M.; Tellez, Guillermo

2016-01-01

Social concern about misuse of antibiotics as growth promoters (AGP) and generation of multidrug-resistant bacteria have restricted the dietary inclusion of antibiotics in livestock feed in several countries. Direct-fed microbials (DFM) are one of the multiple alternatives commonly evaluated as substitutes of AGP. Sporeformer bacteria from the genus Bacillus have been extensively investigated because of their extraordinary properties to form highly resistant endospores, produce antimicrobial compounds, and synthesize different exogenous enzymes. The purpose of the present study was to evaluate and select Bacillus spp. from environmental and poultry sources as DFM candidates, considering their enzyme production profile, biofilm synthesis capacity, and pathogen-inhibition activity. Thirty-one Bacillus isolates were screened for in vitro relative enzyme activity of amylase, protease, lipase, and phytase using a selective media for each enzyme, with 3/31 strains selected as superior enzyme producers. These three isolates were identified as Bacillus subtilis (1/3), and Bacillus amyloliquefaciens (2/3), based on biochemical tests and 16S rRNA sequence analysis. For evaluation of biofilm synthesis, the generation of an adherent crystal violet-stained ring was determined in polypropylene tubes, resulting in 11/31 strains showing a strong biofilm formation. Moreover, all Bacillus strains were evaluated for growth inhibition activity against Salmonella enterica serovar Enteritidis (26/31), Escherichia coli (28/31), and Clostridioides difficile (29/31). Additionally, in previous in vitro and in vivo studies, these selected Bacillus strains have shown to be resistant to different biochemical conditions of the gastrointestinal tract of poultry. Results of the present study suggest that the selection and consumption of Bacillus-DFM, producing a variable set of enzymes and antimicrobial compounds, may contribute to enhanced performance through improving nutrient digestibility, reducing intestinal viscosity, maintaining a beneficial gut microbiota, and promoting healthy intestinal integrity in poultry. PMID:27812526

The role of gut microbiota in the regulation of standard metabolic rate in female Periplaneta americana.

PubMed

Ayayee, Paul A; Ondrejech, Andrew; Keeney, George; Muñoz-Garcia, Agustí

2018-01-01

Insect gut microbiota contribute significantly to host nutritional ecology. Disrupting insect gut microbial assemblages impacts nutrient provisioning functions, and can potentially affect host standard metabolic rate (SMR), a measure of host energy balance. In this study, we evaluated the effect of disrupting gut microbial assemblages on the SMR of female Periplaneta americana cockroaches fed dog food (DF, high protein/carbohydrate (p/c) ratio), and cellulose-amended dog food (CADF, 30% dog food, 70% cellulose, low p/c ratio) diets, supplemented with none, low, or high antibiotic doses. Bacterial loads decreased significantly between diet types ( P = 0.04) and across antibiotic doses ( P = 0.04). There was a significant diet type x antibiotic dose interaction on SMR of females on both diets ( P = 0.05) by the end of the seven-day experimental period. In CADF-fed females, SMR decreased linearly with decreasing bacterial load. However, SMR of DF-fed females on the low dose was significantly higher than those in the control and high dose groups. This is interpreted as a diet-dependent response by low dose DF-fed females to the loss of nutritional services provided by gut bacteria. Severe reductions in bacterial load at high doses reduced SMR of females on both diet types. This study provides insights into the potential role of gut bacteria as modulators of host energy expenditure under varying dietary conditions.

Carbon tetrachloride degradation: Effect of microbial growth substrate and vitamin B{sub 12} content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou, S.; Stensel, H.D.; Ferguson, J.F.

2000-05-01

Microbial degradation kinetics of carbon tetrachloride (CT) under reducing conditions were investigated for different cultures, fed with 1,2-propanediol, dextrose, propionalde-hyde, or acetate and nitrate, in the anaerobic step of an anaerobic/aerobic operation sequence. Methanogenesis was inhibited due to the aerobic step. CT biodegradation rates followed first-order kinetics with respect to CT concentration and biomass and were not affected by the presence of growth substrate. CT degradation rates increased linearly with higher intracellular vitamin B{sub 12} content. The culture fed 1,2-propanediol had the highest vitamin B{sub 12} content, which was 3.8, 4.7, and 16 times that of the propionaldehyde-,dextrose-, and acetate-fedmore » cultures, respectively, and its first-order degradation rate constant was 2.8, 4.5, 6.0 times that for those cultures, respectively. No CT degradation occurred with culture liquid, suggesting that intracellular factors were responsible for CT degradation. The propanediol culture was able to sustain a constant CT degradation rate for a 16-day test period without substrate addition. Compared to a propanediol-fed culture grown only under anaerobic conditions, the propanediol culture grown under the sequential anaerobic/aerobic condition resulted in more biomass growth and a greater CT degradation rate per unit of propanediol fed, although its CT degradation rate per unit of biomass was lower.« less

Effects of partial ruminal defaunation on urea-nitrogen recycling, nitrogen metabolism, and microbial nitrogen supply in growing lambs fed low or high dietary crude protein concentrations.

PubMed

Kiran, D; Mutsvangwa, T

2010-03-01

Urea-nitrogen recycling to the gastrointestinal tract (GIT), N metabolism, and urea transporter-B (UT-B) mRNA abundance in ruminal epithelium were evaluated in partially defaunated (PDFAUN) and faunated (FAUN) growing lambs fed 2 levels (10%, low, or 15%, high) of dietary CP (DM basis). Four Suffolk ram lambs (43.9 +/- 1.4 kg initial BW) were used in a 4 x 4 Latin square design with 27-d periods. Sunflower oil was fed (6%; DM basis) as an anti-protozoal agent. Nitrogen balance was measured from d 22 to 26, with concurrent measurement of urea-N kinetics using continuous intrajugular infusions of [(15)N(15)N]-urea. Feeding sunflower oil decreased (P < 0.01) total ruminal protozoa by 88%, and this was associated with a decrease (P < 0.01) in ruminal ammonia-N concentrations. Endogenous production of urea-N (UER; 26.1 vs. 34.6 g/d) and urea-N loss in urine (UUE; 10.1 vs. 15.7 g/d) were less (P < 0.01), and urea-N entering the GIT (GER; 16.0 vs. 18.9 g/d) tended to be less (P = 0.06) in PDFAUN as compared with FAUN lambs. However, as a proportion of UER, GER was greater (P < 0.01) and the proportion of recycled urea-N that was utilized for anabolism (i.e., UUA) tended to be greater (P = 0.09) in PDFAUN lambs. Partial defaunation increased (P < 0.01) microbial N supply. The UER, GER, and UUE were greater (P < 0.01) in lambs fed the high diet. However, as a proportion of UER, GER and its anabolic use were greater (P < 0.01) in lambs fed the low diet. The expression of UT-B mRNA in PDFAUN lambs was numerically greater (by 20%; P = 0.15) compared with FAUN lambs. In summary, results indicate that part of the mechanism for improved N utilization in defaunated ruminants is an increase in the proportion of endogenous urea-N output that is recycled to the GIT, thus potentially providing additional N for microbial growth.

Effects of the inclusion of a Bacillus direct-fed microbial on performance parameters, bone quality, recovered gut microflora, and intestinal morphology in broilers consuming a grower diet containing corn distillers dried grains with solubles

PubMed Central

Latorre, J. D.; Hernandez-Velasco, X.; Vicente, J. L.; Wolfenden, R.; Hargis, B. M.; Tellez, G.

2017-01-01

Abstract Distillers dried grains with solubles (DDGS) have increasingly been used in poultry diets as a consequence of rising grain costs. Some, but not all, sources of DDGS have a variable compositional value, and a high inclusion of this by-product could be considered a risk factor for presentation of enteric diseases. Presently, 2 experiments were conducted using a starter corn-soybean diet (zero to 7 d) and a corn-DDGS-soybean grower diet (8 to 28 d) with or without inclusion of a Bacillus-direct-fed microbial (DFM). In both experiments, day-of-hatch chicks were randomly assigned to 2 different groups: control group without DFM or Bacillus-DFM group, containing 106 spores/g of feed. In each experiment, 8 pens of 20 chicks (n = 160/group) were used. Performance parameters of BW, BW gain (BWG), feed intake (FI), and feed conversion (FCR) were evaluated in each growth phase. Additionally, in experiment 2, intestinal samples were collected to determine duodenal and ileal morphology (n = 8/group), as well as the microbiota population of total lactic acid bacteria (TLAB), total Gram-negative bacteria (TGNB), and total anaerobic bacteria (TAB) on d 28 (n = 16/group). Furthermore, both tibias were evaluated for bone strength and bone composition (n = 16/group). In both experiments BW, BWG, and FCR were improved by the DFM when compared to the control group (P < 0.05). In experiment 2, chickens supplemented with the DFM had less TGNB in the foregut intestinal segment and higher TLAB counts in both foregut and hindgut sections (P < 0.05). In addition significant increases in tibia breaking strength and bone mineralization were observed in the DFM group when compared with the control. In the case of intestinal morphology, DFM dietary inclusion increased villus height (VH), villus width, villus area, muscular thickness, and the VH to crypt depth ratio (VH:CD) in both duodenum and ileum sections. Results of the present study suggest that consumption of a selected Bacillus-DFM producing a variable set of enzymes could contribute to enhanced performance, intestinal microbial balance, and bone quality in broiler chickens consuming a grower diet that contains corn-DDGS. PMID:28419329

Responses of gut microbiota to diet composition and weight loss in lean and obese mice.

PubMed

Ravussin, Yann; Koren, Omry; Spor, Ayme; LeDuc, Charles; Gutman, Roee; Stombaugh, Jesse; Knight, Rob; Ley, Ruth E; Leibel, Rudolph L

2012-04-01

Maintenance of a reduced body weight is accompanied by a decrease in energy expenditure beyond that accounted for by reduced body mass and composition, as well as by an increased drive to eat. These effects appear to be due--in part--to reductions in circulating leptin concentrations due to loss of body fat. Gut microbiota have been implicated in the regulation of body weight. The effects of weight loss on qualitative aspects of gut microbiota have been studied in humans and mice, but these studies have been confounded by concurrent changes in diet composition, which influence microbial community composition. We studied the impact of 20% weight loss on the microbiota of diet-induced obese (DIO: 60% calories fat) mice on a high-fat diet (HFD). Weight-reduced DIO (DIO-WR) mice had the same body weight and composition as control (CON) ad-libitum (AL) fed mice being fed a control diet (10% calories fat), allowing a direct comparison of diet and weight-perturbation effects. Microbial community composition was assessed by pyrosequencing 16S rRNA genes derived from the ceca of sacrificed animals. There was a strong effect of diet composition on the diversity and composition of the microbiota. The relative abundance of specific members of the microbiota was correlated with circulating leptin concentrations and gene expression levels of inflammation markers in subcutaneous white adipose tissue in all mice. Together, these results suggest that both host adiposity and diet composition impact microbiota composition, possibly through leptin-mediated regulation of mucus production and/or inflammatory processes that alter the gut habitat.

Effects of feeding wheat or corn-wheat dried distillers grains with solubles in low- or high-crude protein diets on ruminal function, omasal nutrient flows, urea-N recycling, and performance in cows.

PubMed

Chibisa, G E; Mutsvangwa, T

2013-10-01

A study was conducted to determine the effects of including either wheat-based (W-DDGS) or corn-wheat blend (B-DDGS) dried distillers grains with solubles as the major protein source in low- or high-crude protein (CP) diets fed to dairy cows on ruminal function, microbial protein synthesis, omasal nutrient flows, urea-N recycling, and milk production. Eight lactating Holstein cows (768.5 ± 57.7 kg of body weight; 109.5 ± 40.0 d in milk) were used in a replicated 4 × 4 Latin square design with 28-d periods (18d of dietary adaptation and 10d of measurements) and a 2 × 2 factorial arrangement of dietary treatments. Four cows in one Latin square were ruminally cannulated for the measurement of ruminal fermentation characteristics, microbial protein synthesis, urea-N recycling kinetics, and omasal nutrient flow. The treatment factors were type of distillers co-product (W-DDGS vs. B-DDGS) and dietary CP content [15.2 vs. 17.3%; dry matter (DM) basis]. The B-DDGS was produced from a mixture of 15% wheat and 85% corn grain. All diets were formulated to contain 10% W-DDGS or B-DDGS on a DM basis. No diet effect was observed on DM intake. Yields of milk, fat, protein, and lactose, and plasma urea-N and milk urea-N concentrations were lower in cows fed the low-CP compared with those fed the high-CP diet. Although feeding B-DDGS tended to reduce ruminal ammonia-N (NH3-N) concentration compared with feeding W-DDGS (9.3 vs. 10.5mg/dL), no differences were observed in plasma urea-N and milk urea-N concentrations. Additionally, dietary inclusion of B-DDGS compared with W-DDGS did not affect rumen-degradable protein supply, omasal flows of total N, microbial nonammonia N (NAN), rumen-undegradable protein, and total NAN, or urea-N recycling kinetics and milk production. However, cows fed the low-CP diet had lower N intake, rumen-degradable protein supply, ruminal NH3-N concentration, and omasal flows of N, microbial NAN, and total NAN compared with those fed the high-CP diet. Feeding the low-CP compared with the high-CP diet also resulted in lower endogenous urea-N production, urea-N recycled to the gastrointestinal tract, and urea-N excretion in urine. In summary, our results indicate that both W-DDGS and B-DDGS can be included as the major protein sources in dairy cow diets without compromising nutrient supply and production performance. However, feeding the low-CP diet lowered omasal flows of microbial protein and metabolizable protein, which, in turn, resulted in lower milk production compared with feeding the high-CP diet. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Electrochemical study of multi-electrode microbial fuel cells under fed-batch and continuous flow conditions

NASA Astrophysics Data System (ADS)

Ren, Lijiao; Ahn, Yongtae; Hou, Huijie; Zhang, Fang; Logan, Bruce E.

2014-07-01

Power production of four hydraulically connected microbial fuel cells (MFCs) was compared with the reactors operated using individual electrical circuits (individual), and when four anodes were wired together and connected to four cathodes all wired together (combined), in fed-batch or continuous flow conditions. Power production under these different conditions could not be made based on a single resistance, but instead required polarization tests to assess individual performance relative to the combined MFCs. Based on the power curves, power produced by the combined MFCs (2.12 ± 0.03 mW, 200 Ω) was the same as the summed power (2.13 mW, 50 Ω) produced by the four individual reactors in fed-batch mode. With continuous flow through the four MFCs, the maximum power (0.59 ± 0.01 mW) produced by the combined MFCs was slightly lower than the summed maximum power of the four individual reactors (0.68 ± 0.02 mW). There was a small parasitic current flow from adjacent anodes and cathodes, but overall performance was relatively unaffected. These findings demonstrate that optimal power production by reactors hydraulically and electrically connected can be predicted from performance by individual reactors.

Impact of temperature and substrate concentration on degradation rates of acetate, propionate and hydrogen and their links to microbial community structure.

PubMed

Zhao, Jing; Westerholm, Maria; Qiao, Wei; Yin, Dongmin; Bi, Shaojie; Jiang, Mengmeng; Dong, Renjie

2018-05-01

The present study investigates the conversion of acetate, propionate and hydrogen consumption linked to the microbial community structure and related to temperature and substrate concentration. Biogas reactors were continuously fed with coffee powder (20 g-COD/L) or acetate (20, 40, and 60 g-COD/L) and operated for 193 days at 37 °C or 55 °C conditions. Starting HRT was 23 days which was then reduced to 7 days. The kinetics of acetate and propionate degradation and hydrogen consumption rates were measured in batch assays. At HRT 7 days, the degradation rate of propionate was higher in thermophilic batches, while acetate degradation rate was higher at mesophilic conditions. The gaseous hydrogen consumption in acetate reactors increased proportionally with temperature and substrate concentration, while the dissolved hydrogen was not affected. The relative high abundance of hydrogentrophic methanogens indicated that the methanogenesis was directed towards the syntrophic acetate oxidation pathway at high acetate concentration and high temperature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characteristics of aerobic granules grown on glucose and acetate in sequential aerobic sludge blanket reactors.

PubMed

Tay, J H; Liu, Q S; Liu, Y

2002-08-01

Aerobic granules were cultivated in two column-type sequential aerobic sludge blanket reactors fed with glucose and acetate, respectively. The characteristics of aerobic granules were investigated. Results indicated that the glucose- and acetate-fed granules have comparable characteristics in terms of settling velocity, size, shape, biomass density, hydrophobicity, physical strength, microbial activity and storage stability. Substrate component does not seem to be a key factor on the formation of aerobic granules. However, microbial diversity of the granules is closely associated with the carbon sources supplied to the reactors. Compared with the conventional activated sludge flocs, aerobic granules exhibit excellent physical characteristics that would be essential for industrial application. This research provides a complete set of characteristics data of aerobic granules grown on glucose and acetate, which would be useful for further development of aerobic granules-based compact bioreactor for handling high strength organic wastewater.

A grey box model of glucose fermentation and syntrophic oxidation in microbial fuel cells.

PubMed

de Los Ángeles Fernandez, Maria; de Los Ángeles Sanromán, Maria; Marks, Stanislaw; Makinia, Jacek; Gonzalez Del Campo, Araceli; Rodrigo, Manuel; Fernandez, Francisco Jesus

2016-01-01

In this work, the fermentative and oxidative processes taking place in a microbial fuel cell (MFC) fed with glucose were studied and modeled. The model accounting for the bioelectrochemical processes was based on ordinary, Monod-type differential equations. The model parameters were estimated using experimental results obtained from three H-type MFCs operated at open or closed circuits and fed with glucose or ethanol. The experimental results demonstrate that similar fermentation processes were carried out under open and closed circuit operation, with the most important fermentation products being ethanol (with a yield of 1.81molmol(-1) glucose) and lactic acid (with a yield of 1.36molmol(-1) glucose). A peak in the electricity generation was obtained when glucose and fermentation products coexisted in the liquid bulk. However, almost 90% of the electricity produced came from the oxidation of ethanol. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance, nitrogen balance and microbial efficiency of beef cattle under concentrate supplementation strategies in intensive management of a tropical pasture.

PubMed

Rocha, Tiago Cunha; Fontes, Carlos Augusto de Alencar; da Silva, Renata Tavares Soares; Processi, Elizabeth Fonsêca; do Valle, Felipe Roberto Amaral Ferreira; Lombardi, Cláudio Teixeira; Oliveira, Ronaldo Lopes; Bezerra, Leilson Rocha

2016-03-01

The objective of this study was to evaluate the effect of concentrate supplementation strategies on the nutritional characteristics of beef cattle in intensive management of tropical pasture. Twenty-four Nellore steer at 250 kg body weight (BW) were used, divided into two plots, with 12 animals in each plot. The experimental area consisted of 32 paddocks with 0.25 ha of Panicum maximum cv. Mombaça. The experiment consisted of 96-day experimental periods, with three periods of 32 days. The strategies studied were P = exclusively on pasture and without concentrate supplementation (control), ES = pasture and supplemented with a concentrate low in protein, PS = pasture and supplemented with high protein content, and PES = pasture and supplementation with balanced protein-energy. There was reduced intake of DM in animals of the treatment P in relation to supplemented pasture, regardless of supplementation. Animals fed on ES showed an intake of more nutrients than the animals on PS. The CP and TDN were also lower in P than in pastures where animals received the additional types of concentrate, and the PS animals showed greater digestibility of CP and TDN than the ES animals. However, the animals exhibited similar weight gains. Animals on P ingested smaller amounts of N and had lower fecal excretion compared to the supplemented animals, but there was no difference between treatments in nitrogen balance. Urea nitrogen and urea from the blood were higher in the supplemented animals than in animals fed on pasture; these levels were also higher in PS animals compared to animals receiving ES. Both the purines absorbed and microbial protein production were similar between treatments. However, the animals fed with concentrate supplementation, independent of the strategy involved, showed higher microbial efficiency compared to animals fed exclusively on pasture.

Greenhouse gas, animal performance, and bacterial population structure responses to dietary monensin fed to dairy cows.

PubMed

Hamilton, Scott W; DePeters, Edward J; McGarvey, Jeffery A; Lathrop, Jeremy; Mitloehner, Frank M

2010-01-01

The present study investigated the effects of a feed additive and rumen microbial modifier, monensin sodium (monensin), on selected variables in lactating dairy cows. Monensin fed cows (MON, 600 mg d(-1)) were compared with untreated control cows (CON, 0 mg d(-1)) with respect to the effects of monensin on the production of three greenhouse gases (GHG), methane (CH(4)), nitrous oxide (N(2)O), and carbon dioxide (CO(2)), along with animal performance (dry matter intake; DMI), milk production, milk components, plasma urea nitrogen (PUN), milk urea nitrogen (MUN), and the microbial population structure of fresh feces. Measurements of GHG were collected at Days 14 and 60 in an environmental chamber simulating commercial dairy freestall housing conditions. Milk production and DMI measurements were collected twice daily over the 60-d experimental period; milk components, PUN, and MUN were measured on Days 14 and 60. The microbial population structure of feces from 6 MON and 6 CON cows was examined on three different occasions (Days 14, 30, and 60). Monensin did not affect emissions of methane (CH(4)), nitrous oxide (N(2)O), and carbon dioxide (CO(2)). Over a 24-h period, emissions of CH(4), N(2)O, and CO(2) decreased in both MON and CON groups. Animal performance and the microbial population structure of the animal fresh waste were also unaffected for MON vs. CON cows.

Two-stage conversion of crude glycerol to energy using dark fermentation linked with microbial fuel cell or microbial electrolysis cell.

PubMed

Chookaew, Teera; Prasertsan, Poonsuk; Ren, Zhiyong Jason

2014-03-25

Crude glycerol is a main byproduct of the biodiesel industry, and the beneficial use of waste glycerol has been a major challenge. This study characterises the conversion of crude glycerol into bioenergy such as H2 and electricity using a two-stage process linking dark fermentation with a microbial fuel cell (MFC) or microbial electrolysis cell (MEC). The results showed that fermentation achieved a maximum H2 rate of 332 mL/L and a yield of 0.55 mol H2/mol glycerol, accompanied by 20% of organic removal. Fed with the raw fermentation products with an initial COD of 7610 mg/L, a two-chamber MFC produced 92 mW/m(2) in power density and removed 50% of COD. The Columbic efficiency was 14%. When fed with 50% diluted fermentation product, a similar power output (90m W/m(2)) and COD removal (49%) were obtained, but the CE doubled to 27%. Similar substrates were used to produce H2 in two-chamber MECs, and the diluted influent had a higher performance, with the highest yield at 106 mL H2/g COD and a CE of 24%. These results demonstrate that dark fermentation linked with MFC/MEC can be a feasible option for conversion of waste glycerol into bioenergy. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of feeding canola meal or wheat dried distillers grains with solubles as a major protein source in low- or high-crude protein diets on ruminal fermentation, omasal flow, and production in cows.

PubMed

Mutsvangwa, T; Kiran, D; Abeysekara, S

2016-02-01

The objective of this study was to determine the effects of feeding canola meal (CM) or wheat dried distillers grains with solubles (W-DDGS) as the major source of protein in diets varying in crude protein (CP) content on ruminal fermentation, microbial protein production, omasal nutrient flow, and production performance in lactating dairy cows. Eight lactating dairy cows were used in a replicated 4×4 Latin square design with 29-d periods (21 d of dietary adaptation and 8 d of measurements) and a 2×2 factorial arrangement of dietary treatments. Four cows in 1 Latin square were ruminally cannulated to allow ruminal and omasal sampling. The treatment factors were (1) source of supplemental protein (CM vs. W-DDGS) and (2) dietary CP content (15 vs. 17%; DM basis). Diets contained 50% forage and 50% concentrate, and were fed twice daily at 0900 and 1600 h as total mixed rations for ad libitum intake. Dry matter intake and milk yield were unaffected by dietary treatments; however, milk yield in cows that were fed CM was numerically greater (+1.1 kg/d) when compared with cows fed W-DDGS. Feeding CM increased milk lactose content compared with feeding W-DDGS. Milk urea nitrogen and ruminal NH3-N concentrations were greater in cows fed the high-CP compared with those fed the low-CP diet. The rumen-degradable protein supply was greater in cows fed the high-CP when compared with those fed the low-CP diet when diets contained CM, whereas rumen-degradable protein supply was lower in cows fed the high-CP when compared with those fed the low-CP diet when diets contained W-DDGS. Total N flow at the omasal canal was not affected by diet; however, omasal flow of NH3-N was greater in cows fed CM when compared with those fed W-DDGS. The rumen-undegradable protein supply was greater in cows fed the low-CP when compared with those fed the high-CP diet when diets contained CM, whereas rumen-undegradable protein supply was lower in cows fed the low-CP when compared with those fed the high-CP diet when diets contained W-DDGS. Omasal flow of fluid-associated bacteria was greater and that of particle-associated bacteria tended to be greater in cows fed CM when compared with those fed W-DDGS; however, omasal flow of total microbial nonammonia N was unaffected by dietary treatment. Omasal flows of threonine and tryptophan were greater, whereas that of histidine and lysine tended to be greater in cows fed CM when compared with those fed W-DDGS. Our results show that when dairy diets are formulated to contain 15 or 17% CP, CM or W-DDGS can be used as the major source of protein and achieve similar levels of milk production. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Electricity generation from synthesis gas by microbial processes: CO fermentation and microbial fuel cell technology.

PubMed

Kim, Daehee; Chang, In Seop

2009-10-01

A microbiological process was established to harvest electricity from the carbon monoxide (CO). A CO fermenter was enriched with CO as the sole carbon source. The DGGE/DNA sequencing results showed that Acetobacterium spp. were enriched from the anaerobic digester fluid. After the fermenter was operated under continuous mode, the products were then continuously fed to the microbial fuel cell (MFC) to generate electricity. Even though the conversion yield was quite low, this study proved that synthesis gas (syn-gas) can be converted to electricity with the aid of microbes that do not possess the drawbacks of metal catalysts of conventional methods.

Effects of Supplementing Microbially-fermented Spent Mushroom Substrates on Growth Performance and Carcass Characteristics of Hanwoo Steers (a Field Study)

PubMed Central

Kim, Y. I.; Lee, Y. H.; Kim, K. H.; Oh, Y. K.; Moon, Y. H.; Kwak, W. S.

2012-01-01

This study evaluated the effect of dietary supplementation of microbially-fermented spent mushroom substrates (MFSMS) on weight gain, carcass characteristics, and economic efficiency of Hanwoo steers. Highly cellulolytic bacteria (Enterobacter spp. and Bacillus spp.) isolated from spent mushroom substrates (SMS) stacks were inoculated (1% v/v) into the SMS, which was anaerobically fermented and fed to the steers for 12.6 months during the growing and fattening periods. Growing Hanwoo steers were assigned to the control group without supplementation of Microbially-fermented SMS (MFSMS), to a treatment group with 50% of MFSMS (1/2 of the ad libitum group), and to a treatment group with ad libitum access to SMS (the ad libitum group). All the groups were fed the formulated feed and rice straw. The voluntary intake (DM basis) of MFSMS was 1.6 kg/d during the growing period and 1.4 kg/d during the fattening period. The voluntary rice straw intake decreased by 6 to 11%, but the total voluntary DMI increased by 7 to 15% with MFSMS fed. The increased DMI with MFSMS supplementation resulted in a tendency of increased (p = 0.055) live weight gain by 8 to 12% compared with the control group. At slaughtering, the supplementation of MFSMS increased (p<0.05) the ribeye area by an average of 10 cm2. In conclusion, feeding MFSMS improved growth performance and carcass traits of Hanwoo steers and could successfully replace a part of conventional roughage such as rice straw commonly used in Asian countries. PMID:25049519

Study of the effect of presence or absence of protozoa on rumen fermentation and microbial protein contribution to the chyme.

PubMed

Belanche, A; Abecia, L; Holtrop, G; Guada, J A; Castrillo, C; de la Fuente, G; Balcells, J

2011-12-01

The aim of this study was to investigate the effect of presence or absence of protozoa on rumen fermentation and efficiency of microbial protein synthesis under different diets. Of 20 twin paired lambs, 1 lamb of each pair was isolated from the ewe within 24 h after birth and reared in a protozoa-free environment (n = 10), whereas their respective twin-siblings remained with the ewe (faunated, n = 10). When lambs reached 6 mo of age, 5 animals of each group were randomly allocated to 1 of 2 experimental diets consisting of either alfalfa hay as the sole diet, or 50:50 mixed with ground barley grain according to a 2 × 2 factorial arrangement of treatments. After 15 d of adaptation to the diet, the animals were euthanized and total rumen and abomasal contents were sampled to estimate rumen microbial synthesis using C(31) alkane as flow marker. Different ((15)N and purine bases) and a novel (recombinant DNA sequences) microbial markers, combined with several microbial reference extracts (rumen protozoa, liquid and solid associated bacteria) were evaluated. Absence of rumen protozoa modified the rumen fermentation pattern and decreased total tract OM and NDF digestibility in 2.0 and 5.1 percentage points, respectively. The effect of defaunation on microbial N flow was weak, however, and was dependent on the microbial marker and microbial reference extract considered. Faunated lambs fed with mixed diet showed the greatest rumen protozoal concentration and the least efficient microbial protein synthesis (29% less than the other treatments), whereas protozoa-free lambs fed with mixed diet presented the smallest ammonia concentration and 34% greater efficiency of N utilization than the other treatments. Although (15)N gave the most precise estimates of microbial synthesis, the use of recombinant DNA sequences represents an alternative that allows separate quantification of the bacteria and protozoa contributions. This marker showed that presence of protozoa decrease the bacterial-N flow through the abomasum by 33%, whereas the protozoa-N contribution to the microbial N flow increased from 1.9 to 14.1% when barley grain was added to the alfalfa hay. Absolute data related to intestinal flow must be treated with caution because the limitations of the sampling and maker system employed.

METHANOGENESIS AND SULFATE REDUCTION IN CHEMOSTATS: I. KINETIC STUDIES AND EXPERIMENTS

EPA Science Inventory

Six anaerobic chemostats containing mixed microbial cultures were used to investigate the interactions between sulfate reduction and methanogenesis for three substrates: acetic acid, methanol and formic acid. Sulfate reducers outcompeted methanogens in acetate-fed chemostats whil...

Corn silage in dairy cow diets to reduce ruminal methanogenesis: effects on the rumen metabolically active microbial communities.

PubMed

Lettat, A; Hassanat, F; Benchaar, C

2013-08-01

Methane produced by the methanogenic Archaea that inhabit the rumen is a potent greenhouse gas and represents an energy loss for the animal. Although several strategies have been proposed to mitigate enteric CH4 production, little is known about the effects of dietary changes on the microbial consortia involved in ruminal methanogenesis. Thus, the current study aimed to examine how the metabolically active microbes are affected when dairy cows were fed diets with increasing proportions of corn silage (CS). For this purpose, 9 ruminally cannulated lactating dairy cows were used in a replicated 3 × 3 Latin square design and fed a total mixed ration (60:40 forage:concentrate ratio on a dry matter basis) with the forage portion being either alfalfa silage (0% CS), corn silage (100% CS), or a 50:50 mixture (50% CS). Enteric CH4 production was determined using respiration chambers and total rumen content was sampled for the determination of fermentation characteristics and molecular biology analyses (cDNA-based length heterogeneity PCR, quantitative PCR). The cDNA-based length heterogeneity PCR targeting active microbes revealed similar bacterial communities in cows fed 0% CS and 50% CS diets, whereas important differences were observed between 0% CS and 100% CS diets, including a reduction in the bacterial richness and diversity in cows fed 100% CS diet. As revealed by quantitative PCR, feeding the 100% CS diet increased the number of total bacteria, Prevotella spp., Archaea, and methanogenic activity, though it reduced protozoal number. Meanwhile, increasing the CS proportion in the diet increased propionate concentration but decreased ruminal pH, CH4 production (L/kg of dry matter intake), and concentrations of acetate and butyrate. Based on these microbial and fermentation changes, and because CH4 production was reduced by feeding 100% CS diet, this study shows that the use of cDNA-based quantitative PCR to estimate archaeal growth and activity is not reliable enough to reflect changes in ruminal methanogenesis. A more robust technique to characterize changes in archaeal community structures will help to better understand the microbial process involved in ruminal methanogenesis and, hence, enabling the development of more effective dietary CH4 mitigation strategies. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of Dietary Cooked Navy Bean on the Fecal Microbiome of Healthy Companion Dogs

PubMed Central

Kerr, Katherine R.; Forster, Genevieve; Dowd, Scot E.; Ryan, Elizabeth P.; Swanson, Kelly S.

2013-01-01

Background Cooked bean powders are a promising novel protein and fiber source for dogs, which have demonstrated potential to alter microbial composition and function for chronic disease control and prevention. This study aimed to determine the impact of cooked navy bean powder fed as a staple food ingredient on the fecal microbiome of healthy adult pet dogs. Methodology/Principal Findings Fecal samples from healthy dogs prior to dietary control and after 4 wk of dietary treatment with macro- and micronutrient matched diets containing either 0 or 25% cooked navy beans (n = 11 and n = 10, respectively) were analyzed by 454-pyrosequencing of the 16S rRNA gene. There were few differences between dogs fed the control and navy bean diets after 4 wk of treatment. These data indicate that there were no major effects of navy bean inclusion on microbial populations. However, significant differences due to dietary intervention onto both research diets were observed (i.e., microbial populations at baseline versus 4 wk of intervention with 0 or 25% navy bean diets). After 4 wk of dietary intervention on either control or navy bean diet, the Phylum Firmicutes was increased and the Phyla Actinobacteria and Fusobacteria were decreased compared to baseline. Conclusions No negative alterations of microbial populations occurred following cooked navy bean intake in dogs, indicating that bean powders may be a viable protein and fiber source for commercial pet foods. The highly variable microbial populations observed in these healthy adult pet dogs at baseline is one potential reason for the difficulty to detect alterations in microbial populations following dietary changes. Given the potential physiological benefits of bean intake in humans and dogs, further evaluation of the impacts of cooked navy bean intake on fecal microbial populations with higher power or more sensitive methods are warranted. PMID:24040374

Bisphenol A alters gut microbiome: Comparative metagenomics analysis.

PubMed

Lai, Keng-Po; Chung, Yan-Tung; Li, Rong; Wan, Hin-Ting; Wong, Chris Kong-Chu

2016-11-01

Mounting evidence has shown that an alteration of the gut microbiota is associated with diet, and plays an important role in animal health and metabolic diseases. However, little is known about the influence of environmental contaminants on the gut microbial community. Bisphenol A (BPA), which is widely used for manufacturing plastic products, has recently been classified as an environmental obesogen. Although many studies have demonstrated the metabolic-disrupting effects of BPA on liver and pancreatic functions, the possible effects of this synthetic compound on the metabolic diversity of the intestinal microbiota is unknown. Using 16S rRNA gene sequencing analysis on caecum samples of CD-1 mice, the present study aimed to test the hypothesis that dietary BPA intake may influence the gut microbiota composition and functions, an important attributing factor to development of the metabolic syndrome. A high-fat diet (HFD) and high-sucrose diet (HSD) were included as the positive controls for comparing the changes in the intestinal microbial profiles. Our results demonstrated a significant reduction of species diversity in the gut microbiota of BPA-fed mice. Alpha and beta diversity analyses showed that dietary BPA intake led to a similar gut microbial community structure as that induced by HFD and HSD in mice. In addition, comparative analysis of the microbial communities revealed that both BPA and a HFD favored the growth of Proteobacteria, a microbial marker of dysbiosis. Consistently, growth induction of the family Helicobacteraceae and reduction of the Firmicutes and Clostridia populations were observed in the mice fed BPA or a HFD. Collectively, our study highlighted that the effects of dietary BPA intake on the shift of microbial community structure were similar to those of a HFD and HSD, and revealed microbial markers for the development of diseases associated with an unstable microbiota. Copyright © 2016 Elsevier Ltd. All rights reserved.

Faecal Microbiota of Forage-Fed Horses in New Zealand and the Population Dynamics of Microbial Communities following Dietary Change

PubMed Central

Fernandes, Karlette A.; Kittelmann, Sandra; Rogers, Christopher W.; Gee, Erica K.; Bolwell, Charlotte F.; Bermingham, Emma N.; Thomas, David G.

2014-01-01

The effects of abrupt dietary transition on the faecal microbiota of forage-fed horses over a 3-week period were investigated. Yearling Thoroughbred fillies reared as a cohort were exclusively fed on either an ensiled conserved forage-grain diet (“Group A”; n = 6) or pasture (“Group B”; n = 6) for three weeks prior to the study. After the Day 0 faecal samples were collected, horses of Group A were abruptly transitioned to pasture. Both groups continued to graze similar pasture for three weeks, with faecal samples collected at 4-day intervals. DNA was isolated from the faeces and microbial 16S and 18S rRNA gene amplicons were generated and analysed by pyrosequencing. The faecal bacterial communities of both groups of horses were highly diverse (Simpson’s index of diversity >0.8), with differences between the two groups on Day 0 (P<0.017 adjusted for multiple comparisons). There were differences between Groups A and B in the relative abundances of four genera, BF311 (family Bacteroidaceae; P = 0.003), CF231 (family Paraprevotellaceae; P = 0.004), and currently unclassified members within the order Clostridiales (P = 0.003) and within the family Lachnospiraceae (P = 0.006). The bacterial community of Group A horses became similar to Group B within four days of feeding on pasture, whereas the structure of the archaeal community remained constant pre- and post-dietary change. The community structure of the faecal microbiota (bacteria, archaea and ciliate protozoa) of pasture-fed horses was also identified. The initial differences observed appeared to be linked to recent dietary history, with the bacterial community of the forage-fed horses responding rapidly to abrupt dietary change. PMID:25383707

Faecal microbiota of forage-fed horses in New Zealand and the population dynamics of microbial communities following dietary change.

PubMed

Fernandes, Karlette A; Kittelmann, Sandra; Rogers, Christopher W; Gee, Erica K; Bolwell, Charlotte F; Bermingham, Emma N; Thomas, David G

2014-01-01

The effects of abrupt dietary transition on the faecal microbiota of forage-fed horses over a 3-week period were investigated. Yearling Thoroughbred fillies reared as a cohort were exclusively fed on either an ensiled conserved forage-grain diet ("Group A"; n = 6) or pasture ("Group B"; n = 6) for three weeks prior to the study. After the Day 0 faecal samples were collected, horses of Group A were abruptly transitioned to pasture. Both groups continued to graze similar pasture for three weeks, with faecal samples collected at 4-day intervals. DNA was isolated from the faeces and microbial 16S and 18S rRNA gene amplicons were generated and analysed by pyrosequencing. The faecal bacterial communities of both groups of horses were highly diverse (Simpson's index of diversity > 0.8), with differences between the two groups on Day 0 (P < 0.017 adjusted for multiple comparisons). There were differences between Groups A and B in the relative abundances of four genera, BF311 (family Bacteroidaceae; P = 0.003), CF231 (family Paraprevotellaceae; P = 0.004), and currently unclassified members within the order Clostridiales (P = 0.003) and within the family Lachnospiraceae (P = 0.006). The bacterial community of Group A horses became similar to Group B within four days of feeding on pasture, whereas the structure of the archaeal community remained constant pre- and post-dietary change. The community structure of the faecal microbiota (bacteria, archaea and ciliate protozoa) of pasture-fed horses was also identified. The initial differences observed appeared to be linked to recent dietary history, with the bacterial community of the forage-fed horses responding rapidly to abrupt dietary change.

Acetate oxidation by syntrophic association between Geobacter sulfurreducens and a hydrogen-utilizing exoelectrogen

PubMed Central

Kimura, Zen-ichiro; Okabe, Satoshi

2013-01-01

Anodic microbial communities in acetate-fed microbial fuel cells (MFCs) were analyzed using stable-isotope probing of 16S rRNA genes followed by denaturing gradient gel electrophoresis. The results revealed that Geobacter sulfurreducens and Hydrogenophaga sp. predominated in the anodic biofilm. Although the predominance of Geobacter sp. as acetoclastic exoelectrogens in acetate-fed MFC systems has been often reported, the ecophysiological role of Hydrogenophaga sp. is unknown. Therefore, we isolated and characterized a bacterium closely related to Hydrogenophaga sp. (designated strain AR20). The newly isolated strain AR20 could use molecular hydrogen (H2), but not acetate, with carbon electrode as the electron acceptor, indicating that the strain AR20 was a hydrogenotrophic exoelectrogen. This evidence raises a hypothesis that acetate was oxidized by G. sulfurreducens in syntrophic cooperation with the strain AR20 as a hydrogen-consuming partner in the acetate-fed MFC. To prove this hypothesis, G. sulfurreducens strain PCA was cocultivated with the strain AR20 in the acetate-fed MFC without any dissolved electron acceptors. In the coculture MFC of G. sulfurreducens and strain AR20, current generation and acetate degradation were the highest, and the growth of strain AR20 was observed. No current generation, acetate degradation and cell growth occurred in the strain AR20 pure culture MFC. These results show for the first time that G. sulfurreducens can oxidize acetate in syntrophic cooperation with the isolated Hydrogenophaga sp. strain AR20, with electrode as the electron acceptor. PMID:23486252

Acetate oxidation by syntrophic association between Geobacter sulfurreducens and a hydrogen-utilizing exoelectrogen.

PubMed

Kimura, Zen-ichiro; Okabe, Satoshi

2013-08-01

Anodic microbial communities in acetate-fed microbial fuel cells (MFCs) were analyzed using stable-isotope probing of 16S rRNA genes followed by denaturing gradient gel electrophoresis. The results revealed that Geobacter sulfurreducens and Hydrogenophaga sp. predominated in the anodic biofilm. Although the predominance of Geobacter sp. as acetoclastic exoelectrogens in acetate-fed MFC systems has been often reported, the ecophysiological role of Hydrogenophaga sp. is unknown. Therefore, we isolated and characterized a bacterium closely related to Hydrogenophaga sp. (designated strain AR20). The newly isolated strain AR20 could use molecular hydrogen (H2), but not acetate, with carbon electrode as the electron acceptor, indicating that the strain AR20 was a hydrogenotrophic exoelectrogen. This evidence raises a hypothesis that acetate was oxidized by G. sulfurreducens in syntrophic cooperation with the strain AR20 as a hydrogen-consuming partner in the acetate-fed MFC. To prove this hypothesis, G. sulfurreducens strain PCA was cocultivated with the strain AR20 in the acetate-fed MFC without any dissolved electron acceptors. In the coculture MFC of G. sulfurreducens and strain AR20, current generation and acetate degradation were the highest, and the growth of strain AR20 was observed. No current generation, acetate degradation and cell growth occurred in the strain AR20 pure culture MFC. These results show for the first time that G. sulfurreducens can oxidize acetate in syntrophic cooperation with the isolated Hydrogenophaga sp. strain AR20, with electrode as the electron acceptor.

Microbial community structure of different electrode materials in constructed wetland incorporating microbial fuel cell.

PubMed

Wang, Junfeng; Song, Xinshan; Wang, Yuhui; Abayneh, Befkadu; Ding, Yi; Yan, Denghua; Bai, Junhong

2016-12-01

The microbial fuel cell coupled with constructed wetland (CW-MFC) microcosms were operated under fed-batch mode for evaluating the effect of electrode materials on bioelectricity generation and microbial community composition. Experimental results indicated that the bioenergy output in CW-MFC increased with the substrate concentration; maximum average voltage (177mV) was observed in CW-MFC with carbon fiber felt (CFF). In addition, the four different materials resulted in the formation of significantly different microbial community distribution around the anode electrode. The relative abundance of Proteobacteria in CFF and foamed nickel (FN) was significantly higher than that in stainless steel mesh (SSM) and graphite rod (GR) samples. Notably, the findings indicate that CW-MFC utilizing FN anode electrode could apparently improve relative abundance of Dechloromonas, which has been regarded as a denitrifying and phosphate accumulating microorganism. Copyright © 2016 Elsevier Ltd. All rights reserved.

Membrane biofouling process correlated to the microbial community succession in an A/O MBR.

PubMed

Chen, Chun-Hong; Fu, Yuan; Gao, Da-Wen

2015-12-01

The microbial community succession of the biofouling layer in a submerged anoxic/oxic membrane biological reactor (A/O MBR) that fed with synthesized domestic wastewater was investigated under three different flux conditions without the changing of the nutrient load. The noticeable microbial community succession and its significant correlation with the metabolic products were observed under the subcritical flux condition. Under the supercritical flux condition, the microbial community shift was in a different pattern compared with that under the subcritical flux condition and it was affected by the increased permeable suction more than the metabolic products. The most abundant microorganisms in the foulants were β-proteobacteria and γ-proteobacteria which can reach more than 20% of the microbial community. However the microorganisms which had significant correlation with the metabolic products were in lower abundance. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of cooked molasses blocks and fermentation extract or brown seaweed meal inclusion on intake, digestion, and microbial efficiency in steers fed low-quality hay.

PubMed

Leupp, J L; Caton, J S; Soto-Navarro, S A; Lardy, G P

2005-12-01

Five ruminally, duodenally, and ileally cannulated steers (376 +/- 8.1 kg of initial BW) were used in a 5 x 5 Latin square to evaluate effects of cooked molasses block supplementation and inclusion of fermentation extract (Aspergillus oryzae) or brown seaweed meal (Ascophyllum nodosum) on intake, site of digestion, and microbial efficiency. Diets consisted of switchgrass hay (6.0% CP; DM basis) offered ad libitum, free access to water, and one of three molasses blocks (0.341 kg of DM/d; one-half at 0600 and one-half at 1800). Treatments were no block (control), block with no additive (40.5% CP; POS), block plus fermentation extract bolused directly into the rumen via gelatin capsules (2.0 g/d; FS), fermentation extract included in the block (2.0 g/d; FB), and seaweed meal included in the block (10 g/d; SB). Steers were adapted to diets for 14 d followed by a 7-d collection period. Overall treatment effect on hay OM intake tended (8.1 vs. 7.6 +/- 0.5 kg/d; P = 0.14) to increase with block supplementation. Total OM intake (8.4 vs. 7.6 +/- 0.5 kg/d; P = 0.01) increased in steers consuming block compared with control. Apparent and true ruminal OM digestibility increased (P = 0.05) with block consumption. Steers fed SB had greater (P = 0.10) true ruminal OM digestibility compared with steers fed POS (61.0 vs. 57.9 +/- 1.6%). True ruminal CP digestibility increased (P = 0.01) with block supplementation compared with control (37.5 vs. 23.6 +/- 3.7%). Addition of fermentation extract did not affect intake or digestion. Treatments did not alter ruminal pH, total VFA, or individual VFA proportions; however, ruminal ammonia increased (P = 0.01) with block supplementation. In situ disappearance rates of hay DM (3.14 +/- 0.44 %/h), NDF (3.18 +/- 0.47 %/h), and ADF (3.02 +/- 0.57 %/h) were not altered by treatment. Seaweed block increased (P = 0.01) slowly degraded CP fraction compared with POS (39.5 vs. 34.0 +/- 2.07%). Similarly, SB increased (P = 0.01) the extent of CP degradability (74.2 vs. 68.9 +/- 1.81%). No treatment effects (P = 0.24) were observed for microbial efficiency. Block supplementation increased intake, and use of brown seaweed meal seemed to have beneficial effects on forage digestibility in low-quality forage diets.

Effect of pre-acclimation of granular activated carbon on microbial electrolysis cell startup and performance.

PubMed

LaBarge, Nicole; Yilmazel, Yasemin Dilsad; Hong, Pei-Ying; Logan, Bruce E

2017-02-01

Microbial electrolysis cells (MECs) can generate methane by fixing carbon dioxide without using expensive catalysts, but the impact of acclimation procedures on subsequent performance has not been investigated. Granular activated carbon (GAC) was used to pre-enrich electrotrophic methanogenic communities, as GAC has been shown to stimulate direct transfer of electrons between different microbial species. MEC startup times using pre-acclimated GAC were improved compared to controls (without pre-acclimation or without GAC), and after three fed batch cycles methane generation rates were similar (P>0.4) for GAC acclimated to hydrogen (22±9.3nmolcm -3 d -1 ), methanol (25±9.7nmolcm -3 d -1 ), and a volatile fatty acid (VFA) mix (22±11nmolcm -3 d -1 ). However, MECs started with GAC but no pre-acclimation had lower methane generation rates (13±4.1nmolcm -3 d -1 ), and MECs without GAC had the lowest rates (0.7±0.8nmolcm -3 d -1 after cycle 2). Microbes previously found in methanogenic MECs, or previously shown to be capable of exocellular electron transfer, were enriched on the GAC. Pre-acclimation using GAC is therefore a simple approach to enrich electroactive communities, improve methane generation rates, and decrease startup times in MECs. Copyright © 2016 Elsevier B.V. All rights reserved.

Interactions between barley grain processing and source of supplemental dietary fat on nitrogen metabolism and urea-nitrogen recycling in dairy cows.

PubMed

Gozho, G N; Hobin, M R; Mutsvangwa, T

2008-01-01

The objective of this study was to determine the effects of methods of barley grain processing and source of supplemental fat on urea-N transfer to the gastrointestinal tract (GIT) and the utilization of this recycled urea-N in lactating dairy cows. Four ruminally cannulated Holstein cows (656.3 +/- 27.7 kg of BW; 79.8 +/- 12.3 d in milk) were used in a 4 x 4 Latin square design with 28-d periods and a 2 x 2 factorial arrangement of dietary treatments. Experimental diets contained dry-rolled barley or pelleted barley in combination with whole canola or whole flaxseed as supplemental fat sources. Nitrogen balance was measured from d 15 to 19, with concurrent measurements of urea-N kinetics using continuous intrajugular infusions of [15N 15N]-urea. Dry matter intake and N intake were higher in cows fed dry-rolled barley compared with those fed pelleted barley. Nitrogen retention was not affected by diet, but fecal N excretion was higher in cows fed dry-rolled barley than in those fed pelleted barley. Actual and energy-corrected milk yield were not affected by diet. Milk fat content and milk fat yield were higher in cows fed dry-rolled barley compared with those fed pelleted barley. Source of supplemental fat did not affect urea-N kinetics. Urea-N production was higher (442.2 vs. 334.3 g of N/d), and urea-N entering the GIT tended to be higher (272.9 vs. 202.0 g of N/d), in cows fed dry-rolled barley compared with those fed pelleted barley. The amount of urea-N entry into the GIT that was returned to the ornithine cycle was higher (204.1 vs. 159.5 g of N/d) in cows fed dry-rolled barley than in pelleted barley-fed cows. The amount of urea-N recycled to the GIT and used for anabolic purposes, and the amounts lost in the urine or feces were not affected by dietary treatment. Microbial nonammonia N supply, estimated using total urinary excretion of purine derivatives, was not affected by diet. These results show that even though barley grain processing altered urea-N entry into the GIT, the utilization of this recycled urea-N for microbial production was unaffected as the additional urea-N, which entered the GIT was returned to ureagenesis.

Beneficial changes in rumen bacterial community profile in sheep and dairy calves as a result of feeding the probiotic Bacillus amyloliquefaciens H57.

PubMed

Schofield, B J; Lachner, N; Le, O T; McNeill, D M; Dart, P; Ouwerkerk, D; Hugenholtz, P; Klieve, A V

2018-03-01

The probiotic Bacillus amyloliquefaciens H57 increased weight gain, increased nitrogen retention and increased feed intake in ruminants when administered to the diet. This study aims to develop a better understanding of this probiotic effect by analysing changes in the rumen prokaryotic community. Sequencing the 16S rRNA gene PCR amplicons of the rumen microbiome, revealed that ewes fed H57 had a significantly different rumen microbial community structure to Control sheep. In contrast, dairy calves showed no significant differences in rumen community structure between treatment groups. In both instances, H57 was below detection in the rumen community profile and was only present at low relative abundance as determined by qPCR. The altered rumen microbial community in sheep likely contributes to increased weight gain through more efficient digestion of plant material. As no change occurred in the rumen community of dairy calves it is suggested that increased weight gain may be due to changes in community function rather than structure. The low relative abundance of H57 as determined by qPCR, suggests that weight gain was not directly mediated by the probiotic, but rather by influencing animal behaviour (feed consumption) and/or altering the native rumen community structure or function. This study provides a novel look at the rumen prokaryotic community in both sheep and dairy calves when fed H57. These findings improve our understanding for the potential rumen community involvement in H57-enabled weight gain. The study reveals that the probiotic B. amyloliquefaciens H57 is capable of benefiting ruminants without colonizing the rumen, suggesting an indirect mechanism of action. © 2018 The Society for Applied Microbiology.

Machine Learning Leveraging Genomes from Metagenomes Identifies Influential Antibiotic Resistance Genes in the Infant Gut Microbiome

PubMed Central

Olm, Matthew R.; Morowitz, Michael J.

2018-01-01

ABSTRACT Antibiotic resistance in pathogens is extensively studied, and yet little is known about how antibiotic resistance genes of typical gut bacteria influence microbiome dynamics. Here, we leveraged genomes from metagenomes to investigate how genes of the premature infant gut resistome correspond to the ability of bacteria to survive under certain environmental and clinical conditions. We found that formula feeding impacts the resistome. Random forest models corroborated by statistical tests revealed that the gut resistome of formula-fed infants is enriched in class D beta-lactamase genes. Interestingly, Clostridium difficile strains harboring this gene are at higher abundance in formula-fed infants than C. difficile strains lacking this gene. Organisms with genes for major facilitator superfamily drug efflux pumps have higher replication rates under all conditions, even in the absence of antibiotic therapy. Using a machine learning approach, we identified genes that are predictive of an organism’s direction of change in relative abundance after administration of vancomycin and cephalosporin antibiotics. The most accurate results were obtained by reducing annotated genomic data to five principal components classified by boosted decision trees. Among the genes involved in predicting whether an organism increased in relative abundance after treatment are those that encode subclass B2 beta-lactamases and transcriptional regulators of vancomycin resistance. This demonstrates that machine learning applied to genome-resolved metagenomics data can identify key genes for survival after antibiotics treatment and predict how organisms in the gut microbiome will respond to antibiotic administration. IMPORTANCE The process of reconstructing genomes from environmental sequence data (genome-resolved metagenomics) allows unique insight into microbial systems. We apply this technique to investigate how the antibiotic resistance genes of bacteria affect their ability to flourish in the gut under various conditions. Our analysis reveals that strain-level selection in formula-fed infants drives enrichment of beta-lactamase genes in the gut resistome. Using genomes from metagenomes, we built a machine learning model to predict how organisms in the gut microbial community respond to perturbation by antibiotics. This may eventually have clinical applications. PMID:29359195

Effects of rapeseed meal fiber content on phosphorus and calcium digestibility in growing pigs fed diets without or with microbial phytase.

PubMed

Bournazel, M; Lessire, M; Duclos, M J; Magnin, M; Même, N; Peyronnet, C; Recoules, E; Quinsac, A; Labussière, E; Narcy, A

2018-01-01

The optimization of dietary phosphorus (P) and calcium (Ca) supply requires a better understanding of the effect of dietary fiber content of co-products on the digestive utilization of minerals. This study was designed to evaluate the effects of dietary fiber content from 00-rapeseed meal (RSM) on P and Ca digestibility throughout the gastrointestinal tract in growing pigs fed diets without or with microbial phytase. In total, 48 castrated male pigs (initial BW=36.1±0.4 kg) were housed in metabolic crates for 29 days. After an 8-day adaptation period, pigs were allocated to one of the eight treatments. The impact of dietary fiber was modulated by adding whole RSM (wRSM), dehulled RSM (dRSM) or dRSM supplemented with 4.5% or 9.0% rapeseed hulls (dRSMh1 and dRSMh2). Diets contained 0 or 500 phytase unit of microbial phytase per kg. From day 14 to day 23, feces and urine were collected separately to determine apparent total tract digestibility (ATTD) and apparent retention (AR) of P and Ca. At the end of the experiment, femurs and digestive contents were sampled. No effect of variables of interest was observed on growth performance. Microbial phytase increased ATTD and AR of P (P<0.001) but the P equivalency with the wRSM diet was lower than expected. Moreover, stomach inorganic P (iP) solubility was improved by microbial phytase (P<0.001). The ATTD of Ca was not affected by microbial phytase which increased AR of Ca and femur characteristics (P<0.05). Ileal recovery of P was not affected by microbial phytase but cecal recovery was considerably reduced by microbial phytase (P<0.001). The decrease in digesta pH between the distal ileum and cecum (7.6 v. 5.9) enhanced the solubility of iP and may have improved its absorption, as supported by the negative relationship between soluble iP and pH (R 2=0.40, P<0.001 without microbial phytase and R 2=0.24, P=0.026 with microbial phytase). The inclusion of hulls improved the solubility of iP (P<0.05). In conclusion, dehulling does not largely increase nutrient digestibility although dRSM seems to improve the efficacy of microbial phytase in releasing phosphate in the stomach. Moreover, dietary fiber may affect solubilization process in the cecum which potentiates the effect of microbial phytase on P digestibility.

Fecal microbiota of lambs fed purple prairie clover (Dalea purpurea Vent.) and alfalfa (Medicago sativa).

PubMed

Huang, Qianqian; Holman, Devin B; Alexander, Trevor; Hu, Tianming; Jin, Long; Xu, Zhongjun; McAllister, Tim A; Acharya, Surya; Zhao, Guoqi; Wang, Yuxi

2018-01-01

The present study assessed the effect of purple prairie clover (PPC) and PPC condensed tannins (CT) on the fecal microbiota of lambs using high-throughput 16S rRNA gene pyrosequencing. A total of 18 individual lambs were randomly divided into three groups and fed either green chop alfalfa (Alf), a 40:60 (DM basis; Mix) mixture of Alf and PPC, or Mix supplemented with polyethylene glycol (Mix-P) for 18 days. Fecal samples were collected on days 13 through 18 using digital rectal retrieval. The DNA of fecal samples was extracted and the microbial 16S rRNA gene amplicons were sequenced using 454 pyrosequencing. Regardless of diet, the bacterial community was dominated by Firmicutes and Bacteroidetes with many sequences unclassified at the genus level. Forage type and CT had no effect on the fecal microbial composition at the phylum level or on α-diversity. Compared to the Alf diet, the Mix diet reduced the relative abundance of Akkermansia (P = 0.03) and Asteroleplasma (P = 0.05). Fecal microbial populations in Alf and Mix-P clustered separately from each other when assessed using unweighted UniFrac (P < 0.05). These results indicate that PPC CT up to 36 g/kg DM in the diet had no major effect on fecal microbial flora at the phyla level and exerted only minor effects on the genera composition of fecal microbiota in lambs.

Formulation of fermentation media from flour-rich waste streams for microbial lipid production by Lipomyces starkeyi.

PubMed

Tsakona, Sofia; Kopsahelis, Nikolaos; Chatzifragkou, Afroditi; Papanikolaou, Seraphim; Kookos, Ioannis K; Koutinas, Apostolis A

2014-11-10

Flour-rich waste (FRW) and by-product streams generated by bakery, confectionery and wheat milling plants could be employed as the sole raw materials for generic fermentation media production, suitable for microbial oil synthesis. Wheat milling by-products were used in solid state fermentations (SSF) of Aspergillus awamori for the production of crude enzymes, mainly glucoamylase and protease. Enzyme-rich SSF solids were subsequently employed for hydrolysis of FRW streams into nutrient-rich fermentation media. Batch hydrolytic experiments using FRW concentrations up to 205 g/L resulted in higher than 90% (w/w) starch to glucose conversion yields and 40% (w/w) total Kjeldahl nitrogen to free amino nitrogen conversion yields. Starch to glucose conversion yields of 98.2, 86.1 and 73.4% (w/w) were achieved when initial FRW concentrations of 235, 300 and 350 g/L were employed in fed-batch hydrolytic experiments, respectively. Crude hydrolysates were used as fermentation media in shake flask cultures with the oleaginous yeast Lipomyces starkeyi DSM 70296 reaching a total dry weight of 30.5 g/L with a microbial oil content of 40.4% (w/w), higher than that achieved in synthetic media. Fed-batch bioreactor cultures led to a total dry weight of 109.8 g/L with a microbial oil content of 57.8% (w/w) and productivity of 0.4 g/L/h. Copyright © 2014 Elsevier B.V. All rights reserved.

Unusual metabolic diversity of hyperalkaliphilic microbial communities associated with subterranean serpentinization at The Cedars.

PubMed

Suzuki, Shino; Ishii, Shun'ichi; Hoshino, Tatsuhiko; Rietze, Amanda; Tenney, Aaron; Morrill, Penny L; Inagaki, Fumio; Kuenen, J Gijs; Nealson, Kenneth H

2017-11-01

Water from The Cedars springs that discharge from serpentinized ultramafic rocks feature highly basic (pH=~12), highly reducing (E h <-550 mV) conditions with low ionic concentrations. These conditions make the springs exceptionally challenging for life. Here, we report the metagenomic data and recovered draft genomes from two different springs, GPS1 and BS5. GPS1, which was fed solely by a deep groundwater source within the serpentinizing system, was dominated by several bacterial taxa from the phyla OD1 ('Parcubacteria') and Chloroflexi. Members of the GPS1 community had, for the most part, the smallest genomes reported for their respective taxa, and encoded only archaeal (A-type) ATP synthases or no ATP synthases at all. Furthermore, none of the members encoded respiration-related genes and some of the members also did not encode key biosynthesis-related genes. In contrast, BS5, fed by shallow water, appears to have a community driven by hydrogen metabolism and was dominated by a diverse group of Proteobacteria similar to those seen in many terrestrial serpentinization sites. Our findings indicated that the harsh ultrabasic geological setting supported unexpectedly diverse microbial metabolic strategies and that the deep-water-fed springs supported a community that was remarkable in its unusual metagenomic and genomic constitution.

The variation of power generation with organic substrates in single-chamber microbial fuel cells (SCMFCs).

PubMed

Sharma, Yogesh; Li, Baikun

2010-03-01

The wastewaters consist of diverse types of organic substrates that can be used as the carbon sources for power generation. To explore the utilization of some of these organics, the electricity generation from three substrates (acetate, ethanol, and glucose) was examined over a concentration range of 0.5-35 mM in single-chamber microbial fuel cells (SCMFCs). The power density generated from glucose was the highest at 401 mW/m(2) followed by acetate and ethanol at 368 mW/m(2) and 302 mW/m(2), respectively. The voltage increased with substrate concentration of 0.5-20mM, but significantly decreased at high substrate concentrations of 20-35 mM. Kinetic analysis indicated that the inhibition in the ethanol-fed MFCs was the highest at the concentration of 35 mM, while inhibition in glucose-fed MFCs was the lowest at the concentration of 20mM. These were in accordance with the extents of voltage decrease at high substrate concentration. Moreover, the effect of the distance between anode and cathode on voltage generation was also investigated. The reduction of the electrode distance by 33% in the glucose-fed MFCs reduced the internal resistance by 73% and led to 20% increase in voltage generation. Published by Elsevier Ltd.

Dietary supplementation with flaxseed meal and oat hulls modulates intestinal histomorphometric characteristics, digesta- and mucosa-associated microbiota in pigs.

PubMed

Ndou, S P; Tun, H M; Kiarie, E; Walsh, M C; Khafipour, E; Nyachoti, C M

2018-04-12

The establishment of a healthy gastrointestinal milieu may not only offer an opportunity to reduce swine production costs but could also open the way for a lifetime of human health improvement. This study investigates the effects of feeding soluble fibre from flaxseed meal-containing diet (FM) and insoluble fibre from oat hulls-containing diet (OH) on histomorphological characteristics, digesta- and mucosa-associated microbiota and their associations with metabolites in pig intestines. In comparison with the control (CON) and OH diets, the consumption of FM increased (P < 0.001) the jejunal villi height (VH) and the ratio of VH to crypt depths. The PERMANOVA analyses showed distinct (P < 0.05) microbial communities in ileal digesta and mucosa, and caecal mucosa in CON and FM-diets fed pigs compared to the OH diet-fed pigs. The predicted functional metagenomes indicated that amino acids and butanoate metabolism, lysine degradation, bile acids biosynthesis, and apoptosis were selectively enhanced at more than 2.2 log-folds in intestinal microbiota of pigs fed the FM diet. Taken together, flaxseed meal and oat hulls supplementation in growing pigs' diets altered the gastrointestinal development, as well as the composition and function of microbial communities, depending on the intestinal segment and physicochemical property of the dietary fibre source.

Influence of the diet components on the symbiotic microorganisms community in hindgut of Coptotermes formosanus Shiraki.

PubMed

Tanaka, Hideo; Aoyagi, Hideki; Shiina, Shunsuke; Shina, Syunsuke; Doudou, Yuri; Dodo, Yuri; Yoshimura, Tsuyoshi; Nakamura, Ryosuke; Uchiyama, Hiroo

2006-08-01

Artificial diet was developed for rearing of lower termites (workers) Coptotermes formosanus. C. formosanus was fed with either wood powder of Japanese red pine, cellulose, cellobiose, or glucose for 30 days. The effect of carbon sources in the diet on the structure and function of the symbiotic intestinal microbial community and on the physiological activity of C. formosanus was studied. Three symbiont protozoa, Pseudotrichonympha grassi, Holomastigotoides hartmanni, and Spirotrichonympha leidyi, were found in the hindgut of C. formosanus that fed on the diets containing carbon sources with high molecular weight (MW). However, when artificial diets containing carbohydrate with low MW were used, both P. grassi and H. hartmanni disappeared, and only few S. leidyi were alive. This suggested that both P. grassi and H. hartmanni play important roles in the digestion and utilization of carbohydrate with high MW. The denaturing gradient gel electrophoresis analysis of bacterial community in the hindgut of termites showed that the similarity between intestinal bacteria community in termites fed with diets containing high-MW carbon sources and those with low MW was only about 40%. It was apparent that changes in diets resulted to changes in intestinal microbial community, and this in turn affected cellulase activity in C. formosanus.

Community proteomics provides functional insight into polyhydroxyalkanoate production by a mixed microbial culture cultivated on fermented dairy manure.

PubMed

Hanson, Andrea J; Guho, Nicholas M; Paszczynski, Andrzej J; Coats, Erik R

2016-09-01

Polyhydroxyalkanoates (PHAs) are bio-based, biodegradable polyesters that can be produced from organic-rich waste streams using mixed microbial cultures (MMCs). To maximize PHA production, MMCs are enriched for bacteria with a high polymer storage capacity through the application of aerobic dynamic feeding (ADF) in a sequencing batch reactor (SBR), which consequently induces a feast-famine metabolic response. Though the feast-famine response is generally understood empirically at a macro-level, the molecular level is less refined. The objective of this study was to investigate the microbial community composition and proteome profile of an enriched MMC cultivated on fermented dairy manure. The enriched MMC exhibited a feast-famine response and was capable of producing up to 40 % (wt. basis) PHA in a fed-batch reactor. High-throughput 16S rRNA gene sequencing revealed a microbial community dominated by Meganema, a known PHA-producing genus not often observed in high abundance in enrichment SBRs. The application of the proteomic methods two-dimensional electrophoresis and LC-MS/MS revealed PHA synthesis, energy generation, and protein synthesis prominently occurring during the feast phase, corroborating bulk solution variable observations and theoretical expectations. During the famine phase, nutrient transport, acyl-CoA metabolism, additional energy generation, and housekeeping functions were more pronounced, informing previously under-determined MMC functionality under famine conditions. During fed-batch PHA production, acetyl-CoA acetyltransferase and PHA granule-bound phasin proteins were in increased abundance relative to the SBR, supporting the higher PHA content observed. Collectively, the results provide unique microbial community structural and functional insight into feast-famine PHA production from waste feedstocks using MMCs.

Interference of age and supplementation of direct-fed microbial and essential oil in the activity of digestive enzymes and expression of genes related to transport and digestion of carbohydrates and proteins in the small intestine of broilers.

PubMed

Fernandez-Alarcon, M F; Trottier, N; Steibel, J P; Lunedo, R; Campos, D M B; Santana, A M; Pizauro, J M; Furlan, R L; Furlan, L R

2017-08-01

The objectives of this study were to describe alterations that age and dietary inclusion of direct-fed microbial (DFM) Bacillus subtilis (BS) and a specific essential oil (EO) blend (carvacrol, cinnamaldehyde, cineol, and pepper extract) causes in the activity of digestive enzymes (maltase: MALT; aminopeptidase-N: APN; intestinal alkaline phosphate: IAP) and expression patterns of genes related to transport (oligopeptide transporter gene: SLC15A1; Na+-dependent glucose and galactose transporter gene: SLC5A1; Na+-independent glucose, galactose, and fructose transporter gene: SLC2A2; ATPase, Na+/K+ transporting gene: ATP1A1) and digestion (aminopeptidase-N gene: ANPEP; maltase-glucoamylase gene: MGAM; Sucrase-isomaltase gene: SI) of carbohydrates and proteins in the small intestine of broilers. Also, the objective was to analyze if growth performance of broilers is affected by supplementation (BS and EO blend). Day-old male broiler chicks (n = 1,320) were assigned to 5 treatments. Diets included a basal diet (BD) as a negative control (CON); experimental diets were BD + BS; BD + BS + EO; BD + EO; BD + antibiotic growth promoter (AGP) avilamycin was the positive control. Performance was evaluated between 1 to 42 d. Transcript abundance of transport-related genes and digestion-related genes were assayed by RT-qPCR and determined at d 7, 21, and 42. MALT-, APN-, and IAP-specific activities were determined at d 7, 21, and 42. Broilers fed BS had greater SLC15A1 mRNA abundance compared to CON, while EO and AGP were related to higher activities of IAP and APN. Analysis over time revealed higher abundance of MGAM, SLC2A2, SLC15A1, SLC5A1 and SI mRNA at d 42 when compared to d 7. Activity of IAP decreased after d 7 and activity of MALT increased with age. The current study suggests that age had effect over carbohydrate and protein transport and carbohydrate digestion. The supplementation of BS DFM hade evident effect over protein transport and that the use of EO in the diet enhanced the activities of carbohydrate and protein digestion, reflecting improvement in digestive and transport physiology of birds. Changes performed by BS DFM and EO did not favor performance. © 2017 Poultry Science Association Inc.

The prebiotics 3′Sialyllactose and 6′Sialyllactose diminish stressor-induced anxiety-like behavior and colonic microbiota alterations: evidence for effects on the gut-brain axis

PubMed Central

Tarr, Andrew J.; Galley, Jeffrey D.; Fisher, Sydney; Chichlowski, Maciej; Berg, Brian M.; Bailey, Michael T.

2015-01-01

There are extensive bidirectional interactions between the gut microbiota and the central nervous system (CNS), and studies demonstrate that stressor exposure significantly alters gut microbiota community structure. We tested whether oligosaccharides naturally found in high levels in human milk, which have been reported to impact brain development and enhance the growth of beneficial commensal microbes, would prevent stressor-induced alterations in gut microbial community composition and attenuate stressor-induced anxiety-like behavior. Mice were fed standard laboratory diet, or laboratory diet containing the human milk oligosaccharides 3′Sialyllactose (3′SL) or 6′Sialyllactose (6′SL) for two weeks prior to being exposed to either a social disruption stressor or a non-stressed control condition. Stressor exposure significantly changed the structure of the colonic mucosa-associated microbiota in control mice, as indicated by changes in beta diversity. The stressor resulted in anxiety-like behavior in both the light/dark preference and open field tests in control mice. This effect was associated with a reduction in immature neurons in the dentate gyrus as indicated by doublecortin (DCX) immunostaining. These effects were not evident in mice fed milk oligosaccharides; stressor exposure did not significantly change microbial community structure in mice fed 3′SL or 6′SL. In addition, 3′SL and 6′SL helped maintain normal behavior on tests of anxiety-like behavior and normal numbers of DCX+ immature neurons. These studies indicate that milk oligosaccharides support normal microbial communities and behavioral responses during stressor exposure, potentially through effects on the gut microbiota-brain axis. PMID:26144888

Rescue of Fructose-Induced Metabolic Syndrome by Antibiotics or Faecal Transplantation in a Rat Model of Obesity.

PubMed

Di Luccia, Blanda; Crescenzo, Raffaella; Mazzoli, Arianna; Cigliano, Luisa; Venditti, Paola; Walser, Jean-Claude; Widmer, Alex; Baccigalupi, Loredana; Ricca, Ezio; Iossa, Susanna

2015-01-01

A fructose-rich diet can induce metabolic syndrome, a combination of health disorders that increases the risk of diabetes and cardiovascular diseases. Diet is also known to alter the microbial composition of the gut, although it is not clear whether such alteration contributes to the development of metabolic syndrome. The aim of this work was to assess the possible link between the gut microbiota and the development of diet-induced metabolic syndrome in a rat model of obesity. Rats were fed either a standard or high-fructose diet. Groups of fructose-fed rats were treated with either antibiotics or faecal samples from control rats by oral gavage. Body composition, plasma metabolic parameters and markers of tissue oxidative stress were measured in all groups. A 16S DNA-sequencing approach was used to evaluate the bacterial composition of the gut of animals under different diets. The fructose-rich diet induced markers of metabolic syndrome, inflammation and oxidative stress, that were all significantly reduced when the animals were treated with antibiotic or faecal samples. The number of members of two bacterial genera, Coprococcus and Ruminococcus, was increased by the fructose-rich diet and reduced by both antibiotic and faecal treatments, pointing to a correlation between their abundance and the development of the metabolic syndrome. Our data indicate that in rats fed a fructose-rich diet the development of metabolic syndrome is directly correlated with variations of the gut content of specific bacterial taxa.

Rescue of Fructose-Induced Metabolic Syndrome by Antibiotics or Faecal Transplantation in a Rat Model of Obesity

PubMed Central

Mazzoli, Arianna; Cigliano, Luisa; Venditti, Paola; Walser, Jean-Claude; Widmer, Alex; Baccigalupi, Loredana; Ricca, Ezio; Iossa, Susanna

2015-01-01

A fructose-rich diet can induce metabolic syndrome, a combination of health disorders that increases the risk of diabetes and cardiovascular diseases. Diet is also known to alter the microbial composition of the gut, although it is not clear whether such alteration contributes to the development of metabolic syndrome. The aim of this work was to assess the possible link between the gut microbiota and the development of diet-induced metabolic syndrome in a rat model of obesity. Rats were fed either a standard or high-fructose diet. Groups of fructose-fed rats were treated with either antibiotics or faecal samples from control rats by oral gavage. Body composition, plasma metabolic parameters and markers of tissue oxidative stress were measured in all groups. A 16S DNA-sequencing approach was used to evaluate the bacterial composition of the gut of animals under different diets. The fructose-rich diet induced markers of metabolic syndrome, inflammation and oxidative stress, that were all significantly reduced when the animals were treated with antibiotic or faecal samples. The number of members of two bacterial genera, Coprococcus and Ruminococcus, was increased by the fructose-rich diet and reduced by both antibiotic and faecal treatments, pointing to a correlation between their abundance and the development of the metabolic syndrome. Our data indicate that in rats fed a fructose-rich diet the development of metabolic syndrome is directly correlated with variations of the gut content of specific bacterial taxa. PMID:26244577

Nitrogen metabolism and route of excretion in beef feedlot cattle fed barley-based finishing diets varying in protein concentration and rumen degradability.

PubMed

Koenig, K M; Beauchemin, K A

2013-05-01

The objectives were to characterize the effects of supplemental CP concentration and ruminal degradability in barley-based finishing diets on microbial protein synthesis, ruminal fermentation and nutrient digestion, and route and chemical form of N excretion in beef cattle. Four Angus heifers (564 ± 18 kg BW) with ruminal and duodenal cannulas were used in an experiment designed as a 4 × 4 Latin square with four 28-d periods (9 d for diet adaptation and 19 d for measurements). The basal diet consisted of 9% barley silage and 91% barley-based concentrate (DM basis). Dietary treatments included the basal diet with no added protein (13% CP) or diets containing 14.5% CP by supplementation with urea (UREA), urea and canola meal (UREA+CM), or urea, corn gluten meal, and xylose-treated soybean meal (UREA+CGM+xSBM). Nutrient digestion was determined using Yb as a digesta flow marker and purine N as a microbial marker with the collection of ruminal, duodenal, and fecal samples over 5 d. The next week, total collections of feces and urine were performed for 5 d to quantify route and chemical form of N excretion. Feed offered was restricted (95% of ad libitum) and there was no effect of the dietary treatments on DMI (P = 0.55); therefore, N intake was less (P < 0.05) in heifers fed the 13% CP diets than the 14.5% CP diets. Supplemental RDP and RUP had no effect on ruminal NH3-N (P = 0.17), peptide N (P = 0.46), and VFA (P = 0.62) concentrations, flow of microbial (P = 0.69) and feed (P = 0.22) N, and ruminal and total tract nutrient digestibility (P ≥ 0.18). Nutrient digestion in the rumen and total tract averaged 75.4 ± 3.8% and 84.6 ± 0.9% for OM, 80.8 ± 3.6% and 95.8 ± 0.8% for starch, and 41.2 ± 7.9% and 60.4 ± 3.3% of intake for NDF, respectively. Daily output of N in feces (P = 0.91) and urine (P = 0.14) were not affected by the dietary treatments. Fecal N output averaged 19.9 ± 1.9% (P = 0.30) and urine N output averaged 44.1 ± 2.8% (P = 0.63) of N intake. Urea N output, however, was greater (P < 0.05) in heifers fed the 14.5% CP than the 13% CP diets and was the major form of N in urine (68.3% in heifers fed the 13% CP diet and 78.7 ± 2.9% in heifers fed the 14.5% CP diets; P < 0.10). Beef cattle fed barley-based finishing diets containing 13% CP do not require additional RDP or RUP to meet microbial or host N requirements. Barley-based finishing diets with no supplemental CP minimized urea N excretion and the potential loss of N from the system.

Effects of different sources of physically effective fiber on rumen microbial populations.

PubMed

Shaw, C N; Kim, M; Eastridge, M L; Yu, Z

2016-03-01

Physically effective fiber is needed by dairy cattle to prevent ruminal acidosis. This study aimed to examine the effects of different sources of physically effective fiber on the populations of fibrolytic bacteria and methanogens. Five ruminally cannulated Holstein cows were each fed five diets differing in physically effective fiber sources over 15 weeks (21 days/period) in a Latin Square design: (1) 44.1% corn silage, (2) 34.0% corn silage plus 11.5% alfalfa hay, (3) 34.0% corn silage plus 5.1% wheat straw, (4) 36.1% corn silage plus 10.1% wheat straw, and (5) 34.0% corn silage plus 5.5% corn stover. The impact of the physically effective fiber sources on total bacteria and archaea were examined using denaturing gradient gel electrophoresis. Specific real-time PCR assays were used to quantify total bacteria, total archaea, the genus Butyrivibrio, Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens and three uncultured rumen bacteria that were identified from adhering ruminal fractions in a previous study. No significant differences were observed among the different sources of physical effective fiber with respect to the microbial populations quantified. Any of the physically effective fiber sources may be fed to dairy cattle without negative impact on the ruminal microbial community.

Comparison of Different Strategies for Selection/Adaptation of Mixed Microbial Cultures Able to Ferment Crude Glycerol Derived from Second-Generation Biodiesel.

PubMed

Varrone, C; Heggeset, T M B; Le, S B; Haugen, T; Markussen, S; Skiadas, I V; Gavala, H N

2015-01-01

Objective of this study was the selection and adaptation of mixed microbial cultures (MMCs), able to ferment crude glycerol generated from animal fat-based biodiesel and produce building-blocks and green chemicals. Various adaptation strategies have been investigated for the enrichment of suitable and stable MMC, trying to overcome inhibition problems and enhance substrate degradation efficiency, as well as generation of soluble fermentation products. Repeated transfers in small batches and fed-batch conditions have been applied, comparing the use of different inoculum, growth media, and Kinetic Control. The adaptation of activated sludge inoculum was performed successfully and continued unhindered for several months. The best results showed a substrate degradation efficiency of almost 100% (about 10 g/L glycerol in 21 h) and different dominant metabolic products were obtained, depending on the selection strategy (mainly 1,3-propanediol, ethanol, or butyrate). On the other hand, anaerobic sludge exhibited inactivation after a few transfers. To circumvent this problem, fed-batch mode was used as an alternative adaptation strategy, which led to effective substrate degradation and high 1,3-propanediol and butyrate production. Changes in microbial composition were monitored by means of Next Generation Sequencing, revealing a dominance of glycerol consuming species, such as Clostridium, Klebsiella, and Escherichia.

Enrichment of denitrifying methane-oxidizing microorganisms using up-flow continuous reactors and batch cultures.

PubMed

Hatamoto, Masashi; Kimura, Masafumi; Sato, Takafumi; Koizumi, Masato; Takahashi, Masanobu; Kawakami, Shuji; Araki, Nobuo; Yamaguchi, Takashi

2014-01-01

Denitrifying anaerobic methane oxidizing (DAMO) microorganisms were enriched from paddy field soils using continuous-flow and batch cultures fed with nitrate or nitrite as a sole electron acceptor. After several months of cultivation, the continuous-flow cultures using nitrite showed remarkable simultaneous methane oxidation and nitrite reduction and DAMO bacteria belonging to phylum NC10 were enriched. A maximum volumetric nitrite consumption rate of 70.4±3.4 mg-N·L(-1)·day(-1) was achieved with very short hydraulic retention time of 2.1 hour. In the culture, about 68% of total microbial cells were bacteria and no archaeal cells were detected by fluorescence in situ hybridization. In the nitrate-fed continuous-flow cultures, 58% of total microbial cells were bacteria while archaeal cells accounted for 7% of total cell numbers. Phylogenetic analysis of pmoA gene sequence showed that enriched DAMO bacteria in the continuous-flow cultivation had over 98% sequence similarity to DAMO bacteria in the inoculum. In contrast, for batch culture, the enriched pmoA gene sequences had 89-91% sequence similarity to DAMO bacteria in the inoculum. These results indicate that electron acceptor and cultivation method strongly affect the microbial community structures of DAMO consortia.

Impact of a novel protein meal on the gastrointestinal microbiota and the host transcriptome of larval zebrafish Danio rerio

PubMed Central

Rurangwa, Eugene; Sipkema, Detmer; Kals, Jeroen; ter Veld, Menno; Forlenza, Maria; Bacanu, Gianina M.; Smidt, Hauke; Palstra, Arjan P.

2015-01-01

Larval zebrafish was subjected to a methodological exploration of the gastrointestinal microbiota and transcriptome. Assessed was the impact of two dietary inclusion levels of a novel protein meal (NPM) of animal origin (ragworm Nereis virens) on the gastrointestinal tract (GIT). Microbial development was assessed over the first 21 days post egg fertilization (dpf) through 16S rRNA gene-based microbial composition profiling by pyrosequencing. Differentially expressed genes in the GIT were demonstrated at 21 dpf by whole transcriptome sequencing (mRNAseq). Larval zebrafish showed rapid temporal changes in microbial colonization but domination occurred by one to three bacterial species generally belonging to Proteobacteria and Firmicutes. The high iron content of NPM may have led to an increased relative abundance of bacteria that were related to potential pathogens and bacteria with an increased iron metabolism. Functional classification of the 328 differentially expressed genes indicated that the GIT of larvae fed at higher NPM level was more active in transmembrane ion transport and protein synthesis. mRNAseq analysis did not reveal a major activation of genes involved in the immune response or indicating differences in iron uptake and homeostasis in zebrafish fed at the high inclusion level of NPM. PMID:25983694

Bioelectricity generation in continuously-fed microbial fuel cell: effects of anode electrode material and hydraulic retention time.

PubMed

Akman, Dilek; Cirik, Kevser; Ozdemir, Sebnem; Ozkaya, Bestamin; Cinar, Ozer

2013-12-01

The main aim of this study is to investigate the bioelectricity production in continuously-fed dual chambered microbial fuel cell (MFC). Initially, MFC was operated with different anode electrode material at constant hydraulic retention time (HRT) of 2d to evaluate the effect of electrode material on electricity production. Pt electrode yielded about 642 mW/m(2) power density, which was 4 times higher than that of the MFC with the mixed metal oxide titanium (Ti-TiO2). Further, MFC equipped with Pt electrode was operated at varying HRT (2-0.5d). The power density generation increased with decreasing HRT, corresponding to 1313 mW/m(2) which was maximum value obtained during this study. Additionally, decreasing HRT from 2 to 0.5d resulted in increasing effluent dissolved organic carbon (DOC) concentration from 1.92 g/L to 2.23 g/L, corresponding to DOC removal efficiencies of 46% and 38%, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impact of volatile fatty acids on microbial electrolysis cell performance.

PubMed

Yang, Nan; Hafez, Hisham; Nakhla, George

2015-10-01

This study investigated the performance of microbial electrolysis cells (MECs) fed with three common fermentation products: acetate, butyrate, and propionate. Each substrate was fed to the reactor for three consecutive-batch cycles. The results showed high current densities for acetate, but low current densities for butyrate and propionate (maximum values were 6.0 ± 0.28, 2.5 ± 0.06, 1.6 ± 0.14 A/m(2), respectively). Acetate also showed a higher coulombic efficiency of 87 ± 5.7% compared to 72 ± 2.0 and 51 ± 6.4% for butyrate and propionate, respectively. This paper also revealed that acetate could be easily oxidized by anode respiring bacteria in MEC, while butyrate and propionate could not be oxidized to the same degree. The utilization rate of the substrates in MEC followed the order: acetate > butyrate > propionate. The ratio of suspended biomass to attached biomass was approximately 1:4 for all the three substrates. Copyright © 2015 Elsevier Ltd. All rights reserved.

The performance and microbial diversity of temperature-phased hyperthermophilic and thermophilic anaerobic digestion system fed with organic waste.

PubMed

Lee, M Y; Cheon, J H; Hidaka, T; Tsuno, H

2008-01-01

The objective of this study was to evaluate the performances and microbial diversities for development of the effective hyperthermophilic digester system that consists of a hyperthermophilic reactor and hyperthermophilic or thermophilic reactor in series. Lab-scale reactors were operated continuously fed with artificial kitchen garbage. The effect of temperature on the acidification step was firstly investigated. Results indicated that 20.8% of COD solubilization was achieved at 70 degrees C, with 12.6% at 80 degrees C. The average protein solubilization reached 31% at 80 degrees C. Methane conversion efficiency following the acidification was around 85% on average at 55 degrees C, but decreased with increasing temperature and methane gas was not produced over 73 degrees C. As well, bacteria affiliated with the methanogens dominated the population below 65 degrees C, while those affiliated with acidogens were predominant over 73 degrees C. These results indicated that the hyperthermophilic process has considerable benefits to treat wastewater or waste containing high concentration of protein.

Bacterial and Protozoal Communities and Fatty Acid Profile in the Rumen of Sheep Fed a Diet Containing Added Tannins ▿

PubMed Central

Vasta, Valentina; Yáñez-Ruiz, David R.; Mele, Marcello; Serra, Andrea; Luciano, Giuseppe; Lanza, Massimiliano; Biondi, Luisa; Priolo, Alessandro

2010-01-01

This study evaluated the effects of tannins on ruminal biohydrogenation (BH) due to shifts in the ruminal microbial environment in sheep. Thirteen lambs (45 days of age) were assigned to two dietary treatments: seven lambs were fed a barley-based concentrate (control group) while the other six lambs received the same concentrate with supplemental quebracho tannins (9.57% of dry matter). At 122 days of age, the lambs were slaughtered, and the ruminal contents were subjected to fatty acid analysis and sampled to quantify populations of Butyrivibrio fibrisolvens, which converts C18:2 c9-c12 (linoleic acid [LA]) to C18:2 c9-t11 (rumenic acid [RA]) and then RA to C18:1 t11 (vaccenic acid [VA]); we also sampled for Butyrivibrio proteoclasticus, which converts VA to C18:0 (stearic acid [SA]). Tannins increased (P < 0.005) VA in the rumen compared to the tannin-free diet. The concentration of SA was not affected by tannins. The SA/VA ratio was lower (P < 0.005) for the tannin-fed lambs than for the controls, suggesting that the last step of the BH process was inhibited by tannins. The B. proteoclasticus population was lower (−30.6%; P < 0.1), and B. fibrisolvens and protozoan populations were higher (+107% and +56.1%, respectively; P < 0.05) in the rumen of lambs fed the tannin-supplemented diet than in controls. These results suggest that quebracho tannins altered BH by changing ruminal microbial populations. PMID:20173064

Bacterial and protozoal communities and fatty acid profile in the rumen of sheep fed a diet containing added tannins.

PubMed

Vasta, Valentina; Yáñez-Ruiz, David R; Mele, Marcello; Serra, Andrea; Luciano, Giuseppe; Lanza, Massimiliano; Biondi, Luisa; Priolo, Alessandro

2010-04-01

This study evaluated the effects of tannins on ruminal biohydrogenation (BH) due to shifts in the ruminal microbial environment in sheep. Thirteen lambs (45 days of age) were assigned to two dietary treatments: seven lambs were fed a barley-based concentrate (control group) while the other six lambs received the same concentrate with supplemental quebracho tannins (9.57% of dry matter). At 122 days of age, the lambs were slaughtered, and the ruminal contents were subjected to fatty acid analysis and sampled to quantify populations of Butyrivibrio fibrisolvens, which converts C(18:2) c9-c12 (linoleic acid [LA]) to C(18:2) c9-t11 (rumenic acid [RA]) and then RA to C(18:1) t11 (vaccenic acid [VA]); we also sampled for Butyrivibrio proteoclasticus, which converts VA to C(18:0) (stearic acid [SA]). Tannins increased (P < 0.005) VA in the rumen compared to the tannin-free diet. The concentration of SA was not affected by tannins. The SA/VA ratio was lower (P < 0.005) for the tannin-fed lambs than for the controls, suggesting that the last step of the BH process was inhibited by tannins. The B. proteoclasticus population was lower (-30.6%; P < 0.1), and B. fibrisolvens and protozoan populations were higher (+107% and +56.1%, respectively; P < 0.05) in the rumen of lambs fed the tannin-supplemented diet than in controls. These results suggest that quebracho tannins altered BH by changing ruminal microbial populations.

Sorghum and wheat differentially affect caecal microbiota and associated performance characteristics of meat chickens.

PubMed

Crisol-Martínez, Eduardo; Stanley, Dragana; Geier, Mark S; Hughes, Robert J; Moore, Robert J

2017-01-01

This study compared the effects of wheat- and sorghum-based diets on broiler chickens. The growth performance and caecal microbial community of chickens were measured and correlations between productivity and specific gut microbes were observed. Cobb broilers 15 days of age were individually caged and two dietary treatments were used, one with a wheat-based diet ( n  = 48) and another one with a sorghum-based diet ( n  = 48). Growth performance measurements were taken over a 10 day period and samples for microbiota analysis were taken at the end of that period. Caecal microbiota was characterised by sequencing of 16S bacterial rRNA gene amplicons. Overall, the results indicated that a sorghum-based diet produced higher apparent metabolisable energy (AME) and body-weight gain (BWG) values in chickens, compared to a wheat-based diet. Nevertheless, sorghum-fed birds had higher feed conversion ratio (FCR) values than wheat-fed birds, possibly because of some anti-nutritional factors in sorghum. Further analyses showed that caecal microbial community was significantly associated with AME values, but microbiota composition differed between dietary treatments. A number of bacteria were individually correlated with growth performance measurements. Numerous OTUs assigned to strains of Lactobacillus crispatus and Lachnospiraceae, which were prevalent in sorghum-fed chickens, were correlated with high AME and BWG values, respectively. Additionally, a number of OTUs assigned to Clostridiales that were prevalent in wheat-fed chickens were correlated with low FCR values. Overall, these results suggest that between-diet variations in growth performance were partly associated with changes in the caecal microbiota.

Gut-Bioreactor and Human Health in Future.

PubMed

Purohit, Hemant J

2018-03-01

Gut-microbiome provides the complementary metabolic potential to the human system. To understand the active participation and the performance of the microbial community in human health, the concept of gut as a plug-flow reactor with the fed-batch mode of operation can provide better insight. The concept suggests the virtual compartmentalized gut with sequential stratification of the microbial community in response to a typical host genotype. It also provides the analysis plan for gut microbiome; and its relevance in developing health management options under the identified clinical conditions.

Finger millet bran supplementation alleviates obesity-induced oxidative stress, inflammation and gut microbial derangements in high-fat diet-fed mice.

PubMed

Murtaza, Nida; Baboota, Ritesh K; Jagtap, Sneha; Singh, Dhirendra P; Khare, Pragyanshu; Sarma, Siddhartha M; Podili, Koteswaraiah; Alagesan, Subramanian; Chandra, T S; Bhutani, K K; Boparai, Ravneet K; Bishnoi, Mahendra; Kondepudi, Kanthi Kiran

2014-11-14

Several epidemiological studies have shown that the consumption of finger millet (FM) alleviates diabetes-related complications. In the present study, the effect of finger millet whole grain (FM-WG) and bran (FM-BR) supplementation was evaluated in high-fat diet-fed LACA mice for 12 weeks. Mice were divided into four groups: control group fed a normal diet (10 % fat as energy); a group fed a high-fat diet; a group fed the same high-fat diet supplemented with FM-BR; a group fed the same high-fat diet supplemented with FM-WG. The inclusion of FM-BR at 10 % (w/w) in a high-fat diet had more beneficial effects than that of FM-WG. FM-BR supplementation prevented body weight gain, improved lipid profile and anti-inflammatory status, alleviated oxidative stress, regulated the expression levels of several obesity-related genes, increased the abundance of beneficial gut bacteria (Lactobacillus, Bifidobacteria and Roseburia) and suppressed the abundance of Enterobacter in caecal contents (P≤ 0·05). In conclusion, FM-BR supplementation could be an effective strategy for preventing high-fat diet-induced changes and developing FM-BR-enriched functional foods.

Effects of a specific blend of essential oils on apparent nutrient digestion, rumen fermentation and rumen microbial populations in sheep fed a 50:50 alfalfa hay:concentrate diet

PubMed Central

Khateri, N.; Azizi, O.; Jahani-Azizabadi, H.

2017-01-01

Objective An experiment was conducted to investigate the effects of a specific mixture of essential oils (MEO), containing thyme, clove and cinnamon EO, on rumen microbial fermentation, nutrient apparent digestibility and blood metabolites in fistulated sheep. Methods Six sheep fitted with ruminal fistulas were used in a repeated measurement design with two 24-d periods to investigate the effect of adding MEO at 0 (control), 0.8, and 1.6 mL/d on apparent nutrient digestibility, rumen fermentation characteristics, rumen microbial population and blood chemical metabolites. Animals were fed with a 50:50 alfalfa hay:concentrate diet. Results Ruminal pH, total volatile fatty acids (VFA) concentration, molar proportion of individual VFA, acetate: propionate ratio and methane production were not affected with MEO. Relative to the control, Small peptides plus amino acid nitrogen and large peptides nitrogen concentration in rumen fluid were not affected with MEO supplementation; while, rumen fluid ammonia nitrogen concentration at 0 and 6 h after morning feeding in sheep fed with 1.6 mL/d of MEO was lower (p<0.05) compared to the control and 0.8 mL/d of MEO. At 0 h after morning feeding, ammonia nitrogen concentration was higher (p<0.05) in sheep fed 0.8 mL/d of MEO relative to 1.6 mL/d and control diet. Ruminal protozoa and hyper ammonia producing (HAP) bacteria counts were not affected by addition of MEO in the diet. Relative to the control, no changes were observed in the red and white blood cells, hemoglobin, hematocrit, glucose, beta-hydroxybutyric acid, cholesterol, total protein, albumin, blood urea nitrogen and aspartate aminotransferase and alanine aminotransferase concentration. Apparent total tract digestibility of dry matter, crude proten, organic matter, and neutral detergent fiber were not influenced by MEO supplementation. Conclusion The results of the present study suggested that supplementation of MEO may have limited effects on apparent nutrient digestibility, ruminal fermentation and protozoa and HAP bacteria count, blood cells and metabolites. PMID:28249376

Enhanced Lipid and Biodiesel Production from Glucose-Fed Activated Sludge: Kinetics an Microbial Community Analysis

EPA Science Inventory

An innovative approach to increase biofuel feedstock lipid yields from municipal sewage sludge via manipulation of carbon:nitrogen (C:N) ratio and glucose loading in activated sludge bioreactors was investigated. Sludge lipid and fatty acid methyl ester (biodiesel) yields (% cel...

Efficacy of the direct-fed microbial Enterococcus faecium alone or in combination with Saccharomyces cerevisiae or Lactococcus lactis during induced subacute ruminal acidosis.

PubMed

Chiquette, J; Lagrost, J; Girard, C L; Talbot, G; Li, S; Plaizier, J C; Hindrichsen, I K

2015-01-01

This study aimed at investigating Enterococcus faecium alone or E. faecium in combination with Saccharomyces cerevisiae or Lactococcus lactis during a subacute ruminal acidosis (SARA) challenge. Four ruminally fistulated Holstein dairy cows were assigned to the following treatments in a 4×4 Latin square design: (1) control (CON); (2) E. faecium (EF); (3) EF + S. cerevisiae (EFSC); (4) EF + L. lactis DSM 11037 (EFLL). Each experimental period consisted of 18 d of adaptation to the respective direct-fed microbial, 3 d of SARA challenge, and 7d of rest. Rumen pH was recorded every 10 min over 24 h on d 17 of adaptation, d 2 of SARA, and d 6 of rest. On the last day of adaptation, SARA, and rest, samples of rumen content (0 and 3 h after feeding) were taken for volatile fatty acids, lactate, vitamin B12, rumen microbes, and lipopolysaccharides determination. Blood samples (0 and 6 h after feeding) were taken for the measurement of acute-phase proteins. Dry matter intake and milk yield were recorded daily. During SARA, mean rumen pH with EFSC (5.94) was not different from that of EFLL (5.95) and tended to be higher than with CON (5.82) or EF (5.82). Postfeeding vitamin B12 concentrations in the rumen were greater with EFSC (134.5ng/g) than with EF (99.6ng/g) and tended to be greater when compared with CON (101.2ng/g) or EFLL (104.9ng/g). During rest, prefeed vitamin B12 was greater with EFSC (166.5ng/g) compared with CON (132.3ng/g). The EFSC treatment did better than EF alone on pH characteristics during adaptation and SARA and on maintenance of ruminal vitamin B12 status during SARA. Milk yield drop from d 1 to 3 of SARA was smaller with EFSC (-0.8kg/d), EF (-0.9kg/d), or EFLL (-0.9kg/d) compared with CON (-7.5kg/d). Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Reduced Burden of Salmonella enterica in Bovine Subiliac Lymph Nodes Associated with Administration of a Direct-fed Microbial.

PubMed

Vipham, J L; Loneragan, G H; Guillen, L M; Brooks, J C; Johnson, B J; Pond, A; Pond, N; Brashears, M M

2015-12-01

Despite effective food safety interventions within abattoirs, Salmonella enterica remains a common contaminant of raw ground beef. Research has recently implicated peripheral lymph nodes (PLNs) as a potential route by which Salmonella contaminates ground beef. This study examined the efficacy of using Lactobacillus animalis (formerly designated Lactobacillus acidophilus; NP51) and Propionibacterium freudenreichii (NP24), at 10(9) cfu/head/day, as a direct-fed microbial (DFM) in feedlot cattle diets to control Salmonella within PLNs. Two studies were conducted in which cattle were randomly allocated into either control or DFM treatment groups. Diets of treated cattle were supplemented with 10(9) cfu/head/day of the DFM, while control groups received no DFM supplementation. During slaughter at abattoirs, one subiliac lymph node (SLN) per carcass was collected from 627 carcasses from one study and 99 carcasses from the second study. Lymph nodes were cultured to estimate the presence and concentration of Salmonella. In the first study, effects of DFM supplementation varied across slaughter days. On the first and second slaughter days, prevalence was reduced by 50% (P = 0.0072) and 31% (P = 0.0093), respectively. No significant difference was observed on slaughter day three (P = 0.1766). In the second study, Salmonella was 82% less likely (P = 0.008) to be recovered from SLNs of treatment cattle. While a greater relative risk reduction was observed in the latter study, absolute risk reductions were similar across studies. A significant reduction in the concentration of Salmonella in SLNs (P < 0.0001) on a cfu/g and cfu/node basis was also observed in cattle administered NP51 and NP24 in the first study; in the second study, too few quantifiable SLNs were observed to facilitate meaningful comparisons. The results indicate that NP51 and NP24 supplementation may aid in reducing the prevalence and concentration of Salmonella in SLNs and, therefore, serve as an effective control measure to reduce Salmonella in ground beef products. © 2015 Blackwell Verlag GmbH.

Effect of Saccharomyces cerevisiae on alfalfa nutrient degradation characteristics and rumen microbial populations of steers fed diets with different concentrate-to-forage ratios.

PubMed

Ding, Gengzhi; Chang, Ying; Zhao, Liping; Zhou, Zhenming; Ren, Liping; Meng, Qingxiang

2014-01-01

Live yeast (Saccharomyces cerevisiae) constitutes an effective additive for animal production; its probiotic effect may be related to the concentrate-to-forage ratio (CTFR). The objective of this study was to assess the effects of S. cerevisiae (SC) on fiber degradation and rumen microbial populations in steers fed diets with different levels of dietary concentrate. Ten Simmental × Local crossbred steers (450 ± 50 kg BW) were assigned to a control group or an SC group. Both groups were fed the same basal diet but the SC group received SC supplementation (8 × 10(9) cfu/h/d through the ruminal fistula) following a two-period crossover design. Each period consisted of four phases, each of which lasted 17 d: 10 d for dietary adaptation, 6 d for degradation study, and 1 d for rumen sample collection. From the 1(st) to the 4(th) phase, steers were fed in a stepwise fashion with increasing CTFRs, i.e., 30:70, 50:50, 70:30, and 90:10. The kinetics of dry matter and fiber degradation of alfalfa pellets were evaluated; the rumen microbial populations were detected using real-time PCR. The results revealed no significant (P > 0.05) interactions between dietary CTFR and SC for most parameters. Dietary CTFR had a significant effect (P < 0.01) on degradation characteristics of alfalfa pellets and the copies of rumen microorganism; the increasing concentrate level resulted in linear, quadratic or cubic variation trend for these parameters. SC supplementation significantly (P < 0.05) affected dry matter (DM) and neutral detergent fiber (NDF) degradation rates (c DM, c NDF) and NDF effective degradability (EDNDF). Compared with the control group, there was an increasing trend of rumen fungi and protozoa in SC group (P < 0.1); copies of total bacteria in SC group were significantly higher (P < 0.05). Additionally, percentage of Ruminobacter amylophilus was significantly lower (P < 0.05) but percentage of Selenomonas ruminantium was significantly higher (P < 0.05) in the SC group. In a word, dietary CTFR had a significant effect on degradation characteristics of forage and rumen microbial population. S. cerevisiae had positive effects on DM and NDF degradation rate or effective degradability of forage; S. cerevisiae increased rumen total bacteria, fungi, protozoa, and lactate-utilizing bacteria but reduced starch-degrading and lactate-producing bacteria.

Non-lethal inhibition of gut microbial trimethylamine production for the treatment of atherosclerosis

PubMed Central

Wang, Zeneng; Roberts, Adam B.; Buffa, Jennifer A.; Levison, Bruce S.; Zhu, Weifei; Org, Elin; Gu, Xiaodong; Huang, Ying; Zamanian-Daryoush, Maryam; Culley, Miranda K.; DiDonato, Anthony J.; Fu, Xiaoming; Hazen, Jennie E.; Krajcik, Daniel; DiDonato, Joseph A.; Lusis, Aldons J.; Hazen, Stanley L.

2016-01-01

SUMMARY Trimethylamine N-oxide (TMAO), a gut microbiota dependent metabolite, both enhances atherosclerosis in animal models and is associated with cardiovascular risks in clinical studies. Here we investigate the impact of targeted inhibition of the first step in TMAO generation, commensal microbial trimethylamine (TMA) production, on diet-induced atherosclerosis. A structural analogue of choline, 3,3-dimethyl-1-butanol (DMB), is shown to non-lethally inhibit TMA formation from cultured microbes, to inhibit distinct microbial TMA lyases, and to both inhibit TMA production from physiologic polymicrobial cultures (eg intestinal contents, human feces) and reduce TMAO levels in mice fed a high choline or carnitine diet. DMB inhibited choline diet-enhanced endogenous macrophage foam cell formation and atherosclerotic lesion development in apolipoprotein e−/− mice without alterations in circulating cholesterol levels. The present studies suggest gut microbial production of TMA specifically, and non-lethal microbial inhibitors in general, may serve as a potential therapeutic approach for the treatment of cardiometabolic diseases. PMID:26687352

Do infants fed directly from the breast have improved appetite regulation and slower growth during early childhood compared with infants fed from a bottle?

PubMed Central

2011-01-01

Background Behavioral mechanisms that contribute to the association between breastfeeding and reduced obesity risk are poorly understood. The purpose of this study was to evaluate the hypothesis that feeding human milk from the breast (direct breastfeeding) has a more optimal association with subsequent child appetite regulation behaviors and growth, when compared to bottle-feeding. Methods Children (n = 109) aged 3- to 6- years were retrospectively classified as directly breastfed (fed exclusively at the breast), bottle-fed human milk, or bottle-fed formula in the first three months of life. Young children's appetite regulation was examined by measuring three constructs (satiety response, food responsiveness, enjoyment of food) associated with obesity risk, using the Child Eating Behavior Questionnaire. Multinomial logistic regression analyses were used to test whether children bottle-fed either human milk or formula had reduced odds of high satiety and increased odds of high food responsiveness and high enjoyment of food compared to children fed directly from the breast. Current child weight status and growth trends from 6-36 months were also examined for their relation to direct breastfeeding and appetite regulation behaviors in early childhood. Results Children fed human milk in a bottle were 67% less likely to have high satiety responsiveness compared to directly breastfed children, after controlling for child age, child weight status, maternal race/ethnicity, and maternal education. There was no association of bottle-feeding (either human milk or formula) with young children's food responsiveness and enjoyment of food. There was neither an association of direct breastfeeding with current child weight status, nor was there a clear difference between directly breastfed and bottle-fed children in growth trajectories from 6- to 36-months. More rapid infant changes in weight-for-age score were associated with lower satiety responsiveness, higher food responsiveness and higher enjoyment of food in later childhood Conclusion While direct breastfeeding was not found to differentially affect growth trajectories from infancy to childhood compared to bottle-feeding, results suggest direct breastfeeding during early infancy is associated with greater appetite regulation later in childhood. A better understanding of such behavioral distinctions between direct breastfeeding and bottle-feeding may identify new pathways to reduce the pediatric obesity epidemic. PMID:21849028

Electricity generation from food wastes and microbial community structure in microbial fuel cells.

PubMed

Jia, Jianna; Tang, Yu; Liu, Bingfeng; Wu, Di; Ren, Nanqi; Xing, Defeng

2013-09-01

Microbial fuel cell (MFC) was studied as an alternate and a novel way to dispose food wastes (FWs) in a waste-to-energy form. Different organic loading rate obviously affected the performance of MFCs fed with FWs. The maximum power density of ~18 W/m(3) (~556 mW/m(2)) was obtained at COD of 3200±400 mg/L and the maximum coulombic efficiency (CE) was ~27.0% at COD of 4900±350 mg/L. The maximum removals of COD, total carbohydrate (TC) and total nitrogen (TN) were ~86.4%, ~95.9% and ~16.1%, respectively. Microbial community analysis using 454 pyrosequencing of 16S rRNA gene demonstrated the combination of the dominant genera of the exoelectrogenic Geobacter and fermentative Bacteroides effectively drove highly efficient and reliable MFC systems with functions of organic matters degradation and electricity generation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dynamics of Cathode-Associated Microbial Communities and Metabolite Profiles in a Glycerol-Fed Bioelectrochemical System

PubMed Central

Dennis, Paul G.; Harnisch, Falk; Yeoh, Yun Kit; Tyson, Gene W.

2013-01-01

Electrical current can be used to supply reducing power to microbial metabolism. This phenomenon is typically studied in pure cultures with added redox mediators to transfer charge. Here, we investigate the development of a current-fed mixed microbial community fermenting glycerol at the cathode of a bioelectrochemical system in the absence of added mediators and identify correlations between microbial diversity and the respective product outcomes. Within 1 week of inoculation, a Citrobacter population represented 95 to 99% of the community and the metabolite profiles were dominated by 1,3-propanediol and ethanol. Over time, the Citrobacter population decreased in abundance while that of a Pectinatus population and the formation of propionate increased. After 6 weeks, several Clostridium populations and the production of valerate increased, which suggests that chain elongation was being performed. Current supply was stopped after 9 weeks and was associated with a decrease in glycerol degradation and alcohol formation. This decrease was reversed by resuming current supply; however, when hydrogen gas was bubbled through the reactor during open-circuit operation (open-circuit potential) as an alternative source of reducing power, glycerol degradation and metabolite production were unaffected. Cyclic voltammetry revealed that the community appeared to catalyze the hydrogen evolution reaction, leading to a +400-mV shift in its onset potential. Our results clearly demonstrate that current supply can alter fermentation profiles; however, further work is needed to determine the mechanisms behind this effect. In addition, operational conditions must be refined to gain greater control over community composition and metabolic outcomes. PMID:23603684

Phylogenetic and Metagenomic Analyses of Substrate-Dependent Bacterial Temporal Dynamics in Microbial Fuel Cells

PubMed Central

Zhang, Husen; Chen, Xi; Braithwaite, Daniel; He, Zhen

2014-01-01

Understanding the microbial community structure and genetic potential of anode biofilms is key to improve extracellular electron transfers in microbial fuel cells. We investigated effect of substrate and temporal dynamics of anodic biofilm communities using phylogenetic and metagenomic approaches in parallel with electrochemical characterizations. The startup non-steady state anodic bacterial structures were compared for a simple substrate, acetate, and for a complex substrate, landfill leachate, using a single-chamber air-cathode microbial fuel cell. Principal coordinate analysis showed that distinct community structures were formed with each substrate type. The bacterial diversity measured as Shannon index decreased with time in acetate cycles, and was restored with the introduction of leachate. The change of diversity was accompanied by an opposite trend in the relative abundance of Geobacter-affiliated phylotypes, which were acclimated to over 40% of total Bacteria at the end of acetate-fed conditions then declined in the leachate cycles. The transition from acetate to leachate caused a decrease in output power density from 243±13 mW/m2 to 140±11 mW/m2, accompanied by a decrease in Coulombic electron recovery from 18±3% to 9±3%. The leachate cycles selected protein-degrading phylotypes within phylum Synergistetes. Metagenomic shotgun sequencing showed that leachate-fed communities had higher cell motility genes including bacterial chemotaxis and flagellar assembly, and increased gene abundance related to metal resistance, antibiotic resistance, and quorum sensing. These differentially represented genes suggested an altered anodic biofilm community in response to additional substrates and stress from the complex landfill leachate. PMID:25202990

Phylogenetic and metagenomic analyses of substrate-dependent bacterial temporal dynamics in microbial fuel cells.

PubMed

Zhang, Husen; Chen, Xi; Braithwaite, Daniel; He, Zhen

2014-01-01

Understanding the microbial community structure and genetic potential of anode biofilms is key to improve extracellular electron transfers in microbial fuel cells. We investigated effect of substrate and temporal dynamics of anodic biofilm communities using phylogenetic and metagenomic approaches in parallel with electrochemical characterizations. The startup non-steady state anodic bacterial structures were compared for a simple substrate, acetate, and for a complex substrate, landfill leachate, using a single-chamber air-cathode microbial fuel cell. Principal coordinate analysis showed that distinct community structures were formed with each substrate type. The bacterial diversity measured as Shannon index decreased with time in acetate cycles, and was restored with the introduction of leachate. The change of diversity was accompanied by an opposite trend in the relative abundance of Geobacter-affiliated phylotypes, which were acclimated to over 40% of total Bacteria at the end of acetate-fed conditions then declined in the leachate cycles. The transition from acetate to leachate caused a decrease in output power density from 243±13 mW/m2 to 140±11 mW/m2, accompanied by a decrease in Coulombic electron recovery from 18±3% to 9±3%. The leachate cycles selected protein-degrading phylotypes within phylum Synergistetes. Metagenomic shotgun sequencing showed that leachate-fed communities had higher cell motility genes including bacterial chemotaxis and flagellar assembly, and increased gene abundance related to metal resistance, antibiotic resistance, and quorum sensing. These differentially represented genes suggested an altered anodic biofilm community in response to additional substrates and stress from the complex landfill leachate.

Bioreactor performance and functional gene analysis of microbial community in a limited-oxygen fed bioreactor for co-reduction of sulfate and nitrate with high organic input.

PubMed

Xu, Xi-jun; Chen, Chuan; Wang, Ai-jie; Yu, Hao; Zhou, Xu; Guo, Hong-liang; Yuan, Ye; Lee, Duu-jong; Zhou, Jizhong; Ren, Nan-qi

2014-08-15

Limited-oxygen mediated synergistic relationships between sulfate-reducing bacteria (SRB), nitrate-reducing bacteria (NRB) and sulfide-oxidizing bacteria (SOB, including nitrate-reducing, sulfide-oxidizing bacteria NR-SOB) were predicted to simultaneously remove contaminants of nitrate, sulfate and high COD, and eliminate sulfide generation. A lab-scale experiment was conducted to examine the impact of limited oxygen on these oxy-anions degradation, sulfide oxidation and associated microbial functional responses. In all scenarios tested, the reduction of both nitrate and sulfate was almost complete. When limited-oxygen was fed into bioreactors, S(0) formation was significantly improved up to ∼ 70%. GeoChip 4.0, a functional gene microarray, was used to determine the microbial gene diversity and functional potential for nitrate and sulfate reduction, and sulfide oxidation. The diversity of the microbial community in bioreactors was increased with the feeding of limited oxygen. Whereas the intensities of the functional genes involved in sulfate reduction did not show a significant difference, the abundance of the detected denitrification genes decreased in limited oxygen samples. More importantly, sulfide-oxidizing bacteria may alter their populations/genes in response to limited oxygen potentially to function more effectively in sulfide oxidation, especially to elemental sulfur. The genes fccA/fccB from nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB), such as Paracoccus denitrificans, Thiobacillus denitrificans, Beggiatoa sp., Thiomicrospira sp., and Thioalkalivibrio sp., were more abundant under limited-oxygen condition. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of advanced oxidation on N-nitrosodimethylamine (NDMA) formation and microbial ecology during pilot-scale biological activated carbon filtration.

PubMed

Li, Dong; Stanford, Ben; Dickenson, Eric; Khunjar, Wendell O; Homme, Carissa L; Rosenfeldt, Erik J; Sharp, Jonathan O

2017-04-15

Water treatment combining advanced oxidative processes with subsequent exposure to biological activated carbon (BAC) holds promise for the attenuation of recalcitrant pollutants. Here we contrast oxidation and subsequent biofiltration of treated wastewater effluent employing either ozone or UV/H 2 O 2 followed by BAC during pilot-scale implementation. Both treatment trains largely met target water quality goals by facilitating the removal of a suite of trace organics and bulk water parameters. N-nitrosodimethylamine (NDMA) formation was observed in ozone fed BAC columns during biofiltration and to a lesser extent in UV/H 2 O 2 fed columns and was most pronounced at 20 min of empty bed contact time (EBCT) when compared to shorter EBCTs evaluated. While microbial populations were highly similar in the upper reaches, deeper samples revealed a divergence within and between BAC filtration systems where EBCT was identified to be a significant environmental predictor for shifts in microbial populations. The abundance of Nitrospira in the top samples of both columns provides an explanation for the oxidation of nitrite and corresponding increases in nitrate concentrations during BAC transit and support interplay between nitrogen cycling with nitrosamine formation. The results of this study demonstrate that pretreatments using ozone versus UV/H 2 O 2 impart modest differences to the overall BAC microbial population structural and functional attributes, and further highlight the need to evaluate NDMA formation prior to full-scale implementation of BAC in potable reuse applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigation of microbial diversity in the feces of cattle fed different diets

USDA-ARS?s Scientific Manuscript database

Understanding of the bovine fecal microbiome could contribute to solving issues regarding animal production, cattle health and food safety. The objective of this study was to examine the influence of diet on the fecal microbiome in feedlot cattle. The next-generation pyrosequencing technology was us...

Effects of Resource Chemistry on the Composition and Function of Stream Hyporheic Biofilms

PubMed Central

Hall, E. K.; Besemer, K.; Kohl, L.; Preiler, C.; Riedel, K.; Schneider, T.; Wanek, W.; Battin, T. J.

2012-01-01

Fluvial ecosystems process large quantities of dissolved organic matter as it moves from the headwater streams to the sea. In particular, hyporheic sediments are centers of high biogeochemical reactivity due to their elevated residence time and high microbial biomass and activity. However, the interaction between organic matter and microbial dynamics in the hyporheic zone remains poorly understood. We evaluated how variance in resource chemistry affected the microbial community and its associated activity in experimentally grown hyporheic biofilms. To do this we fed beech leaf leachates that differed in chemical composition to a series of bioreactors filled with sediment from a sub-alpine stream. Differences in resource chemistry resulted in differences in diversity and phylogenetic origin of microbial proteins, enzyme activity, and microbial biomass stoichiometry. Specifically, increased lignin, phenolics, and manganese in a single leachate resulted in increased phenoloxidase and peroxidase activity, elevated microbial biomass carbon:nitrogen ratio, and a greater proportion of proteins of Betaproteobacteria origin. We used this model system to attempt to link microbial form (community composition and metaproteome) with function (enzyme activity) in order to better understand the mechanisms that link resource heterogeneity to ecosystem function in stream ecosystems. PMID:22347877

Effects of resource chemistry on the composition and function of stream hyporheic biofilms.

USGS Publications Warehouse

Hall, E.K.; Besemer, K.; Kohl, L.; Preiler, C.; Reidel, K.; Schneider, T.; Wanek, W.; Battin, T.J.

2012-01-01

Fluvial ecosystems process large quantities of dissolved organic matter as it moves from the headwater streams to the sea. In particular, hyporheic sediments are centers of high biogeochemical reactivity due to their elevated residence time and high microbial biomass and activity. However, the interaction between organic matter and microbial dynamics in the hyporheic zone remains poorly understood. We evaluated how variance in resource chemistry affected the microbial community and its associated activity in experimentally grown hyporheic biofilms. To do this we fed beech leaf leachates that differed in chemical composition to a series of bioreactors filled with sediment from a sub-alpine stream. Differences in resource chemistry resulted in differences in diversity and phylogenetic origin of microbial proteins, enzyme activity, and microbial biomass stoichiometry. Specifically, increased lignin, phenolics, and manganese in a single leachate resulted in increased phenoloxidase and peroxidase activity, elevated microbial biomass carbon:nitrogen ratio, and a greater proportion of proteins of Betaproteobacteria origin. We used this model system to attempt to link microbial form (community composition and metaproteome) with function (enzyme activity) in order to better understand the mechanisms that link resource heterogeneity to ecosystem function in stream ecosystems.

Sources of Variation in the Gut Microbial Community of Lycaeides melissa Caterpillars.

PubMed

Chaturvedi, Samridhi; Rego, Alexandre; Lucas, Lauren K; Gompert, Zachariah

2017-09-12

Microbes can mediate insect-plant interactions and have been implicated in major evolutionary transitions to herbivory. Whether microbes also play a role in more modest host shifts or expansions in herbivorous insects is less clear. Here we evaluate the potential for gut microbial communities to constrain or facilitate host plant use in the Melissa blue butterfly (Lycaeides melissa). We conducted a larval rearing experiment where caterpillars from two populations were fed plant tissue from two hosts. We used 16S rRNA sequencing to quantify the relative effects of sample type (frass versus whole caterpillar), diet (plant species), butterfly population and development (caterpillar age) on the composition and diversity of the caterpillar gut microbial communities, and secondly, to test for a relationship between microbial community and larval performance. Gut microbial communities varied over time (that is, with caterpillar age) and differed between frass and whole caterpillar samples. Diet (host plant) and butterfly population had much more limited effects on microbial communities. We found no evidence that gut microbe community composition was associated with caterpillar weight, and thus, our results provide no support for the hypothesis that variation in microbial community affects performance in L. melissa.

Pregnancy-related changes in the maternal gut microbiota are dependent upon the mother's periconceptional diet

PubMed Central

Gohir, Wajiha; Whelan, Fiona J; Surette, Michael G; Moore, Caroline; Schertzer, Jonathan D; Sloboda, Deborah M

2015-01-01

Shifts in the maternal gut microbiome have been implicated in metabolic adaptations to pregnancy. We investigated how pregnancy and diet interact to influence the composition of the maternal gut microbiota. Female C57BL/6 mice were fed either a control or a high fat diet for 8 weeks prior to mating. After confirmation of pregnancy, maternal weight gain and food intake were recorded. Fecal pellets were collected at 2 timepoints prior to mating (at the beginning of the experiment, and after 6 weeks of the specified diet) and at 4 timepoints during pregnancy (gestation day 0.5, 5.5, 10.5, and 15.5). The microbial composition and predicted metabolic functionality of the non-pregnant and pregnant gut was determined via sequencing of the variable 3 region of the 16S rRNA gene. Upon conception, differences in gut microbial communities were observed in both control and high fat-fed mice, including an increase in mucin-degrading bacteria. Control versus high fat-fed pregnant mice possessed the most profound changes to their maternal gut microbiota as indicated by statistically significant taxonomic differences. High fat-fed pregnant mice, when compared to control-fed animals, were found to be significantly enriched in microbes involved in metabolic pathways favoring fatty acid, ketone, vitamin, and bile synthesis. We show that pregnancy-induced changes in the female gut microbiota occur immediately at the onset of pregnancy, are vulnerable to modulation by diet, but are not dependent upon increases in maternal weight gain during pregnancy. High fat diet intake before and during pregnancy results in distinctive shifts in the pregnant gut microbiota in a gestational-age dependent manner and these shifts predict significant differences in the abundance of genes that favor lipid metabolism, glycolysis and gluconeogenic metabolic pathways over the course of pregnancy. PMID:26322500

Single-chamber microbial fuel cells as on-line shock-sensors for volatile fatty acids in anaerobic digesters.

PubMed

Schievano, Andrea; Colombo, Alessandra; Cossettini, Alessandra; Goglio, Andrea; D'Ardes, Vincenzo; Trasatti, Stefano; Cristiani, Pierangela

2018-01-01

In anaerobic digesters (AD), volatile fatty acids (VFAs) concentration is a critical operative parameter, which is usually manually monitored to prevent inhibition of microbial consortia. An on-line VFAs monitoring system as early-warning for increasing concentrations would be of great help for operators. Here, air-cathode membraneless microbial fuel cells (MFCs) were investigated as potential biosensors, whose electrical signal instantaneously moves from its steady value with the accumulation of VFAs in the anodic solution. MFCs were operated equipping four lab-scale ADs with carbon-based electrodes. Reactors were filled with the digestate from a full-scale AD and fed in batch with four kinds of feedstock (cheese whey, kitchen waste, citrus pulp and fishery waste). The MFC signal initially increased in parallel to VFAs production, then tended to a steady value for VFAs concentrations above 1000mg Ac L -1 . Peak concentrations of tVFAs (2500-4500mg Ac L -1 ) and MFCs potentials were negatively correlated (r=0.916, p<0.05), regardless of the type of substrate. Inhibition of the MFC system occurred when VFAs increased fast above 4000mg Ac L -1 . Polarization curves of electrodes stressed that electroactive bacteria on bioanodes were strongly subjected to inhibition. The inhibition of electroactivity on bioanode trended like typical shock-sensors, opening to direct application as early-warning monitoring system in full-scale ADs. Copyright © 2017 Elsevier Ltd. All rights reserved.

In Vitro Continuous Fermentation Model (PolyFermS) of the Swine Proximal Colon for Simultaneous Testing on the Same Gut Microbiota

PubMed Central

Tanner, Sabine A.; Zihler Berner, Annina; Rigozzi, Eugenia; Grattepanche, Franck; Chassard, Christophe; Lacroix, Christophe

2014-01-01

In vitro gut modeling provides a useful platform for a fast and reproducible assessment of treatment-related changes. Currently, pig intestinal fermentation models are mainly batch models with important inherent limitations. In this study we developed a novel in vitro continuous fermentation model, mimicking the porcine proximal colon, which we validated during 54 days of fermentation. This model, based on our recent PolyFermS design, allows comparing different treatment effects on the same microbiota. It is composed of a first-stage inoculum reactor seeded with immobilized fecal swine microbiota and used to constantly inoculate (10% v/v) five second-stage reactors, with all reactors fed with fresh nutritive chyme medium and set to mimic the swine proximal colon. Reactor effluents were analyzed for metabolite concentrations and bacterial composition by HPLC and quantitative PCR, and microbial diversity was assessed by 454 pyrosequencing. The novel PolyFermS featured stable microbial composition, diversity and metabolite production, consistent with bacterial activity reported for swine proximal colon in vivo. The constant inoculation provided by the inoculum reactor generated reproducible microbial ecosystems in all second-stage reactors, allowing the simultaneous investigation and direct comparison of different treatments on the same porcine gut microbiota. Our data demonstrate the unique features of this novel PolyFermS design for the swine proximal colon. The model provides a tool for efficient, reproducible and cost-effective screening of environmental factors, such as dietary additives, on pig colonic fermentation. PMID:24709947

In vitro continuous fermentation model (PolyFermS) of the swine proximal colon for simultaneous testing on the same gut microbiota.

PubMed

Tanner, Sabine A; Zihler Berner, Annina; Rigozzi, Eugenia; Grattepanche, Franck; Chassard, Christophe; Lacroix, Christophe

2014-01-01

In vitro gut modeling provides a useful platform for a fast and reproducible assessment of treatment-related changes. Currently, pig intestinal fermentation models are mainly batch models with important inherent limitations. In this study we developed a novel in vitro continuous fermentation model, mimicking the porcine proximal colon, which we validated during 54 days of fermentation. This model, based on our recent PolyFermS design, allows comparing different treatment effects on the same microbiota. It is composed of a first-stage inoculum reactor seeded with immobilized fecal swine microbiota and used to constantly inoculate (10% v/v) five second-stage reactors, with all reactors fed with fresh nutritive chyme medium and set to mimic the swine proximal colon. Reactor effluents were analyzed for metabolite concentrations and bacterial composition by HPLC and quantitative PCR, and microbial diversity was assessed by 454 pyrosequencing. The novel PolyFermS featured stable microbial composition, diversity and metabolite production, consistent with bacterial activity reported for swine proximal colon in vivo. The constant inoculation provided by the inoculum reactor generated reproducible microbial ecosystems in all second-stage reactors, allowing the simultaneous investigation and direct comparison of different treatments on the same porcine gut microbiota. Our data demonstrate the unique features of this novel PolyFermS design for the swine proximal colon. The model provides a tool for efficient, reproducible and cost-effective screening of environmental factors, such as dietary additives, on pig colonic fermentation.

Biotic Interactions in Microbial Communities as Modulators of Biogeochemical Processes: Methanotrophy as a Model System

PubMed Central

Ho, Adrian; Angel, Roey; Veraart, Annelies J.; Daebeler, Anne; Jia, Zhongjun; Kim, Sang Yoon; Kerckhof, Frederiek-Maarten; Boon, Nico; Bodelier, Paul L. E.

2016-01-01

Microbial interaction is an integral component of microbial ecology studies, yet the role, extent, and relevance of microbial interaction in community functioning remains unclear, particularly in the context of global biogeochemical cycles. While many studies have shed light on the physico-chemical cues affecting specific processes, (micro)biotic controls and interactions potentially steering microbial communities leading to altered functioning are less known. Yet, recent accumulating evidence suggests that the concerted actions of a community can be significantly different from the combined effects of individual microorganisms, giving rise to emergent properties. Here, we exemplify the importance of microbial interaction for ecosystem processes by analysis of a reasonably well-understood microbial guild, namely, aerobic methane-oxidizing bacteria (MOB). We reviewed the literature which provided compelling evidence for the relevance of microbial interaction in modulating methane oxidation. Support for microbial associations within methane-fed communities is sought by a re-analysis of literature data derived from stable isotope probing studies of various complex environmental settings. Putative positive interactions between active MOB and other microbes were assessed by a correlation network-based analysis with datasets covering diverse environments where closely interacting members of a consortium can potentially alter the methane oxidation activity. Although, methanotrophy is used as a model system, the fundamentals of our postulations may be applicable to other microbial guilds mediating other biogeochemical processes. PMID:27602021

Continuous flow operation with appropriately adjusting composites in influent for recovery of Cr(VI), Cu(II) and Cd(II) in self-driven MFC-MEC system.

PubMed

Li, Ming; Pan, Yuzhen; Huang, Liping; Zhang, Yong; Yang, Jinhui

2017-03-01

A self-driven microbial fuel cell (MFC) - microbial electrolysis cell (MEC) system, where electricity generated from MFCs is in situ utilized for powering MECs, has been previously reported for recovering Cr(VI), Cu(II) and Cd(II) with individual metals fed in different units of the system in batch operation. Here it was advanced with treating synthetic mixed metals' solution at appropriately adjusting composites in fed-batch and continuous flow operations for complete separation of Cr(VI), Cu(II) and Cd(II) from each other. Under an optimal condition of hydraulic residence time of 4 h, matching of two serially connected MFCs with one MEC, and fed with a composite of either 5 mg L -1 Cr(VI), 1 mg L -1 Cu(II) and 5 mg L -1 Cd(II), or 1 mg L -1 Cr(VI), 5 mg L -1 Cu(II) and 5 mg L -1 Cd(II), the self-driven MFC-MEC system can completely and sequentially recover Cu(II), Cr(VI) and Cd(II) from mixed metals. This study provides a true sustainable and zero-energy-consumed approach of using bioelectrochemical systems for completely recovering and separating Cr(VI), Cu(II) and Cd(II) from each other or from wastes or contaminated sites.

Effects of carbon brush anode size and loading on microbial fuel cell performance in batch and continuous mode

NASA Astrophysics Data System (ADS)

Lanas, Vanessa; Ahn, Yongtae; Logan, Bruce E.

2014-02-01

Larger scale microbial fuel cells (MFCs) require compact architectures to efficiently treat wastewater. We examined how anode-brush diameter, number of anodes, and electrode spacing affected the performance of the MFCs operated in fed-batch and continuous flow mode. All anodes were initially tested with the brush core set at the same distance from the cathode. In fed-batch mode, the configuration with three larger brushes (25 mm diameter) produced 80% more power (1240 mW m-2) than reactors with eight smaller brushes (8 mm) (690 mW m-2). The higher power production by the larger brushes was due to more negative and stable anode potentials than the smaller brushes. The same general result was obtained in continuous flow operation, although power densities were reduced. However, by moving the center of the smaller brushes closer to the cathode (from 16.5 to 8 mm), power substantially increased from 690 to 1030 mW m-2 in fed batch mode. In continuous flow mode, power increased from 280 to 1020 mW m-2, resulting in more power production from the smaller brushes than the larger brushes (540 mW m-2). These results show that multi-electrode MFCs can be optimized by selecting smaller anodes, placed as close as possible to the cathode.

Influence of maternal breast milk ingestion on acquisition of the intestinal microbiome in preterm infants.

PubMed

Gregory, Katherine E; Samuel, Buck S; Houghteling, Pearl; Shan, Guru; Ausubel, Frederick M; Sadreyev, Ruslan I; Walker, W Allan

2016-12-30

The initial acquisition and early development of the intestinal microbiome during infancy are important to human health across the lifespan. Mode of birth, antibiotic administration, environment of care, and nutrition have all been shown to play a role in the assembly of the intestinal microbiome during early life. For preterm infants, who are disproportionately at risk of inflammatory intestinal disease (i.e., necrotizing enterocolitis), a unique set of clinical factors influence the establishment of the microbiome. The purpose of this study was to establish the influence of nutritional exposures on the intestinal microbiome in a cohort of preterm infants early in life. Principal component analysis of 199 samples from 30 preterm infants (<32 weeks) over the first 60 days following birth showed that the intestinal microbiome was influenced by postnatal time (p < 0.001, R 2  = 0.13), birth weight (p < 0.001, R 2  = 0.08), and nutrition (p < 0.001, R 2  = 0.21). Infants who were fed breast milk had a greater initial bacterial diversity and a more gradual acquisition of diversity compared to infants who were fed infant formula. The microbiome of infants fed breast milk were more similar regardless of birth weight (p = 0.049), in contrast to the microbiome of infants fed infant formula, which clustered differently based on birth weight (p < 0.001). By adjusting for differences in gut maturity, an ordered succession of microbial phylotypes was observed in breast milk-fed infants, which appeared to be disrupted in those fed infant formula. Supplementation with pasteurized donor human milk was partially successful in promoting a microbiome more similar to breast milk-fed infants and moderating rapid increases in bacterial diversity. The preterm infant intestinal microbiome is influenced by postnatal time, birth weight, gestational age, and nutrition. Feeding with breast milk appears to mask the influence of birth weight, suggesting a protective effect against gut immaturity in the preterm infant. These findings suggest not only a microbial mechanism underpinning the body of evidence showing that breast milk promotes intestinal health in the preterm infant but also a dynamic interplay of host and dietary factors that facilitate the colonization of and enrichment for specific microbes during establishment of the preterm infant microbiota.

Effects of chito-oligosaccharide supplementation on performance, nutrient digestibility, and serum composition in broiler chickens.

PubMed

Li, X J; Piao, X S; Kim, S W; Liu, P; Wang, L; Shen, Y B; Jung, S C; Lee, H S

2007-06-01

A total of 196 day-old male broiler chicks were randomly allocated to 1 of 4 treatments in a study conducted to determine the effects of dietary supplementation of chito-oligosaccharide (COS) on growth, nutrient digestibility, and serum composition. The experimental diets consisted of an unsupplemented control diet based on corn, soybean meal, and fish meal or similar diets supplemented with either chlortetracycline, 50 mg/kg of COS, or 100 mg/kg of COS. Each treatment was fed to 7 replicate pens of birds, with 7 birds per pen. Broiler performance, nutrient digestibility, cecal microbial concentrations, and serum indices were measured at the end of the starter (d 21) and grower phases (d 42). During the starter period and overall, broilers fed 50 or 100 mg/kg of COS had better (P<0.05) average daily gain, average daily feed intake, and feed conversion than the control birds. The performance of birds fed chlortetracycline was generally intermediate between that of the control and the 2 COS treatments. Compared with the birds in the control or chlortetracycline treatments, the birds receiving 100 mg/kg of COS had better nutrient digestibility of DM, energy, calcium, and phosphorus; higher (P<0.05) concentrations of cecal Lactobacillus; and lower (P<0.05) serum triglyceride and total cholesterol during the starter phase. During the grower phase, the birds fed 100 mg/kg of COS had higher (P<0.05) calcium digestibility and CP retention than those fed the chlortetracycline treatment, and lower concentrations of cecal Escherichia coli than birds in the control treatment. The serum growth hormone level in birds fed 50 mg/kg of COS was higher (P<0.05) than in the other treatments. The birds fed 100 mg/kg of COS had lower (P<0.05) serum triglyceride, higher (P<0.05) serum high-density lipoprotein cholesterol, and higher serum total protein content than birds in the other treatments. In conclusion, dietary supplementation with COS appeared to improve the average daily gain of broilers by increasing the average daily feed intake and nutrient digestibility and modulating the concentrations of cecal microbial flora. Additionally, COS increased serum protein and high-density lipoprotein cholesterol and decreased serum triglyceride.

In vitro evaluation, in vivo quantification, and microbial diversity studies of nutritional strategies for reducing enteric methane production.

PubMed

Abdalla, Adibe Luiz; Louvandini, Helder; Sallam, Sobhy Mohamed Abdallah Hassan; Bueno, Ives Cláudio da Silva; Tsai, Siu Mui; Figueira, Antonio Vargas de Oliveira

2012-06-01

The main objective of the present work was to study nutritive strategies for lessening the CH(4) formation associated to ruminant tropical diets. In vitro gas production technique was used for evaluating the effect of tannin-rich plants, essential oils, and biodiesel co-products on CH(4) formation in three individual studies and a small chamber system to measure CH(4) released by sheep for in vivo studies was developed. Microbial rumen population diversity from in vitro assays was studied using qPCR. In vitro studies with tanniniferous plants, herbal plant essential oils derived from thyme, fennel, ginger, black seed, and Eucalyptus oil (EuO) added to the basal diet and cakes of oleaginous plants (cotton, palm, castor plant, turnip, and lupine), which were included in the basal diet to replace soybean meal, presented significant differences regarding fermentation gas production and CH(4) formation. In vivo assays were performed according to the results of the in vitro assays. Mimosa caesalpineaefolia, when supplemented to a basal diet (Tifton-85 hay Cynodon sp, corn grain, soybean meal, cotton seed meal, and mineral mixture) fed to adult Santa Ines sheep reduced enteric CH(4) emission but the supplementation of the basal diet with EuO did not affect (P > 0.05) methane released. Regarding the microbial studies of rumen population diversity using qPCR with DNA samples collected from the in vitro trials, the results showed shifts in microbial communities of the tannin-rich plants in relation to control plant. This research demonstrated that tannin-rich M. caesepineapholia, essential oil from eucalyptus, and biodiesel co-products either in vitro or in vivo assays showed potential to mitigate CH(4) emission in ruminants. The microbial community study suggested that the reduction in CH(4) production may be attributed to a decrease in fermentable substrate rather than to a direct effect on methanogenesis.

Effects of supplemental ruminally degradable protein versus increasing amounts of supplemental ruminally undegradable protein on site and extent of digestion and ruminal characteristics in lambs fed low-quality forage.

PubMed

Atkinson, R L; Toone, C D; Ludden, P A

2007-12-01

Four ruminally and duodenally cannulated Suffolk wether lambs (34.5 +/- 2 kg initial BW) were used in a 4 x 4 Latin square designed experiment to compare effects of supplemental ruminally degradable protein (RDP) vs. increasing amounts of supplemental ruminally undegradable protein (RUP) on ruminal characteristics and site and extent of digestion in lambs. Lambs were fed a basal diet of crested wheatgrass hay (4.2% CP) for ad libitum consumption, plus 1 of 4 protein supplements: isolated soy protein (RDP source) fed to meet estimated RDP requirements assuming a microbial efficiency of 11% of TDN (CON) or corn gluten meal (RUP source) fed at 50, 100, or 150% of the supplemental N provided by CON (C50, C100, and C150, respectively). Neither NDF nor ADF intake was affected (P >/= 0.18) by protein degradability, but they increased or tended to increase (P /= 0.26) for CON and C100, but increased (P /= 0.33) by protein degradability. However, true ruminal N digestibility was greater (P = 0.03) for CON compared with C100. Ruminal ammonia concentrations were greater (P = 0.002) for CON compared with C100 lambs, and increased (P = 0.001) with increasing RUP. Microbial N flows were not affected (P >/= 0.12) by protein degradability or increasing RUP. Likewise, neither ruminal urease activity (P >/= 0.11) nor microbial efficiency (P >/= 0.50) were affected by protein degradability or level of RUP. Total tract OM, NDF, and ADF digestibility was greater (P

Stable isotope probing of acetate fed anaerobic batch incubations shows a partial resistance of acetoclastic methanogenesis catalyzed by Methanosarcina to sudden increase of ammonia level.

PubMed

Hao, Liping; Lü, Fan; Mazéas, Laurent; Desmond-Le Quéméner, Elie; Madigou, Céline; Guenne, Angéline; Shao, Liming; Bouchez, Théodore; He, Pinjing

2015-02-01

Ammonia inhibition represents a major operational issue for anaerobic digestion. In order to refine our understanding of the terminal catabolic steps in thermophilic anaerobic digestion under ammonia stress, we studied batch thermophilic acetate fed experiments at low (0.26 g L(-1)) and high (7.00 g L(-1)) Total Ammonia Nitrogen concentrations (TAN). Although methane production started immediately for all incubations and resulted in methane yields close to stoichiometric expectations, a 62-72% decrease of methanogenic rate was observed throughout the incubation at 7.00 g L(-1) of TAN compared to 0.26 g L(-1). Stable Isotope Probing analysis of active microbial communities in (13)C-acetate fed experiments coupled to automated ribosomal intergenic spacer analysis and 16S rDNA pyrotag sequencing confirmed that microbial communities were similar for both TAN conditions. At both TAN levels, the (13)C-labeled bacterial community was mainly affiliated to Clostridia-relatives, with OPB54 bacteria being the most abundant sequence in the heavy DNA 16S rDNA pyrotag library. Sequences closely related to Methanosarcina thermophila were also abundantly retrieved in the heavy DNA fractions, showing that this methanogen was still actively assimilating labeled carbon from acetate at free ammonia nitrogen concentrations up to 916 mg L(-1). Stable isotopic signature analysis of biogas, measured in unlabeled acetate fed experiments that were conducted in parallel, confirmed that acetoclastic methanogenic pathway was dominant at both ammonia concentrations. Our work demonstrates that, besides the syntrophic acetate oxidation pathway, acetoclastic methanogenesis catalyzed by Methanosarcina can also play a major role in methane production at high ammonia levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Diets Alter the Gut Microbiome of Crocodile Lizards

PubMed Central

Jiang, Hai-Ying; Ma, Jing-E; Li, Juan; Zhang, Xiu-Juan; Li, Lin-Miao; He, Nan; Liu, Hai-Yang; Luo, Shu-Yi; Wu, Zheng-Jun; Han, Ri-Chou; Chen, Jin-Ping

2017-01-01

The crocodile lizard is a critically endangered reptile, and serious diseases have been found in this species in recent years, especially in captive lizards. Whether these diseases are caused by changes in the gut microbiota and the effect of captivity on disease remains to be determined. Here, we examined the relationship between the gut microbiota and diet and disease by comparing the fecal microbiota of wild lizards with those of sick and healthy lizards in captivity. The gut microbiota in wild crocodile lizards was consistently dominated by Proteobacteria (∼56.4%) and Bacteroidetes (∼19.1%). However, the abundance of Firmicutes (∼2.6%) in the intestine of the wild crocodile lizards was distinctly lower than that in other vertebrates. In addition, the wild samples from Guangdong Luokeng Shinisaurus crocodilurus National Nature Reserve also had a high abundance of Deinococcus–Thermus while the wild samples from Guangxi Daguishan Crocodile Lizard National Nature Reserve had a high abundance of Tenericutes. The gut microbial community in loach-fed crocodile lizards was significantly different from the gut microbial community in the earthworm-fed and wild lizards. In addition, significant differences in specific bacteria were detected among groups. Notably, in the gut microbiota, the captive lizards fed earthworms resulted in enrichment of Fusobacterium, and the captive lizards fed loaches had higher abundances of Elizabethkingia, Halomonas, Morganella, and Salmonella, all of which are pathogens or opportunistic pathogens in human or other animals. However, there is no sufficient evidence that the gut microbiota contributes to either disease A or disease B. These results provide a reference for the conservation of endangered crocodile lizards and the first insight into the relationship between disease and the gut microbiota in lizards. PMID:29118742

Recipient-Biased Competition for an Intracellularly Generated Cross-Fed Nutrient Is Required for Coexistence of Microbial Mutualists

PubMed Central

McCully, Alexandra L.; LaSarre, Breah

2017-01-01

ABSTRACT Many mutualistic microbial relationships are based on nutrient cross-feeding. Traditionally, cross-feeding is viewed as being unidirectional, from the producer to the recipient. This is likely true when a producer’s waste, such as a fermentation product, has value only for a recipient. However, in some cases the cross-fed nutrient holds value for both the producer and the recipient. In such cases, there is potential for nutrient reacquisition by producer cells in a population, leading to competition against recipients. Here, we investigated the consequences of interpartner competition for cross-fed nutrients on mutualism dynamics by using an anaerobic coculture pairing fermentative Escherichia coli and phototrophic Rhodopseudomonas palustris. In this coculture, E. coli excretes waste organic acids that provide a carbon source for R. palustris. In return, R. palustris cross-feeds E. coli ammonium (NH4+), a compound that both species value. To explore the potential for interpartner competition, we first used a kinetic model to simulate cocultures with varied affinities for NH4+ in each species. The model predicted that interpartner competition for NH4+ could profoundly impact population dynamics. We then experimentally tested the predictions by culturing mutants lacking NH4+ transporters in both NH4+ competition assays and mutualistic cocultures. Both theoretical and experimental results indicated that the recipient must have a competitive advantage in acquiring cross-fed NH4+ to sustain the mutualism. This recipient-biased competitive advantage is predicted to be crucial, particularly when the communally valuable nutrient is generated intracellularly. Thus, the very metabolites that form the basis for mutualistic cross-feeding can also be subject to competition between mutualistic partners. PMID:29184014

Effects of feeding different levels of dietary fiber through the addition of corn stover on nutrient utilization of dairy heifers precision-fed high and low concentrate diets.

PubMed

Lascano, G J; Heinrichs, A J

2011-06-01

The objective of this experiment was to assess the effects of manipulating dietary fiber by replacing corn silage (CS) with lower quality forage as corn stover (CST) when used in high concentrate (HC) and low concentrate (LC) diets for precision-fed dairy heifers. Eight Holstein heifers (335.6 ± 7.41 kg of body weight) were randomly assigned to 2 levels of concentrate: HC (20% forage) and LC (80% forage), and to a forage type sequence [0% of forage as corn stover (CST), 100% corn silage (CS); 20% CST, 80% CS; 40% CST, 60% CS; and 60% CST, 40% CS] within concentrate level administered according to a split-plot, 4 × 4 Latin square design (21-d periods). Heifers fed HC had higher apparent total-tract dry matter digestibility (DMD). Increasing the fiber level by increasing the amount of CST in the diet resulted in a linear decrease of DMD and organic matter digestibility. Heifers fed LC diets had higher neutral detergent fiber (NDF) digestibility and tended to have lower acid detergent fiber (ADF) digestibility than those fed HC diets. Substituting CS with 20% CST resulted in the highest NDF and ADF digestibilities. Digestibility of N was not different, but N retention increased for HC and decreased quadratically for LC diets. Heifers fed HC diets decreased fecal output, and CST linearly increased these parameters. Urine volume tended to be higher for HC-fed heifers, and increasing dietary fiber through CST inclusion tended to decrease urine output. This shift in water excretion resulted in similar total manure output. Total purine derivative excretion did not differ between treatments, but interacted with CST addition, resulting in a linear increase in microbial protein flow to the duodenum in HC-fed heifers and in a linear decrease in LC diets as CST increased. In conclusion, increasing dietary fiber through CST decreased DMD and organic matter digestibility linearly, whereas NDF and ADF digestibility were maximized when 20% CST was added to HC and LC diets. Microbial protein synthesis increased and decreased linearly with CST addition in HC and LC diets, respectively. Retention of N increased and decreased quadratically with CST addition in HC and LC diets, respectively. Total manure excretion was not different between HC or LC diets. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Growth performance of calves fed microbially enhanced soy protein in pelleted starters.

PubMed

Senevirathne, N D; Anderson, J L; Gibbons, W R; Clapper, J A

2017-01-01

Our objective was to determine effects of feeding calves pelleted starters with microbially enhanced (fungi-treated) soy protein (MSP) in replacement of soybean meal (SBM) with different milk replacers (MR). Thirty-six Holstein calves (2 d old; 24 females, 12 males) in individual hutches were used in a 12-wk randomized complete block design study. Treatments were (1) MSP pellets with MR formulated for accelerated growth (28% crude protein, 18% fat; MSPA), (2) SBM pellets with MR formulated for accelerated growth (SBMA), and (3) MSP pellets with conventional MR (20% crude protein, 20% fat; MSPC). Pellets were similar except for 23% MSP or 23% SBM (dry matter basis). Pellets and water were fed ad libitum throughout the study. Feeding rates of MR on a dry matter basis were 0.37kg twice daily during wk 1, 0.45kg twice daily during wk 2 to 5, and 0.45kg once daily during wk 6. Intakes were recorded daily. Body weights, frame size measurements, and jugular blood samples were collected 2 d every 2 wk at 3 h after the morning feeding. Fecal grab samples were collected 5 times per d for 3 d during wk 12 and then composited by calf for analysis of apparent total-tract digestibility of nutrients using acid detergent insoluble ash as an internal marker. Total and starter pellet dry matter intake were greatest for calves fed SBMA and least for MSPC. Calves had similar average daily gain among treatments, but there was a treatment by week interaction and during the last few weeks of the study calves on MSPC had less body weight compared with MSPA or SBMA. Gain-to-feed ratio was similar among treatments; however, there was a treatment by week interaction. Serum glucose was similar among treatments. Plasma urea nitrogen was greatest for calves fed MSPA and least for MSPC. Plasma concentrations of IGF-1 were greatest for calves fed SBMA. Plasma concentrations of triglycerides were greatest for calves fed MSPC. Plasma concentrations of β-hydroxybutyrate had a treatment by time interaction. Treatments had similar total-tract dry matter digestibility, but calves fed MSPC had greater crude protein digestibility than SBMA, with MSPA similar to both. Results demonstrated calves fed pelleted starters with MSP had maintained growth performance with less starter intake compared with SBM. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Brewers dried yeast as a source of mannan oligosaccharides for weanling pigs.

PubMed

White, L A; Newman, M C; Cromwell, G L; Lindemann, M D

2002-10-01

Brewers dried yeast, a source of mannan oligosaccharides (MOS), was assessed as an alternative to an antimicrobial agent (carbadox) for young pigs in two experiments. The yeast contained 5.2% MOS. Agglutination tests confirmed adsorption of several serovars of E. coli and Salmonella spp. onto the yeast product. In Exp. 1, seven replicates (five pigs per pen) of 22-d-old pigs were fed a nonmedicated basal diet or the basal diet with carbadox (55 mg/kg), yeast (3%), or a combination of 3% yeast and 2% citric acid for 28 d. Carbadox did not improve growth performance. Growth rate and feed intake were depressed (P < 0.05) in pigs fed yeast alone or in combination with acid. Log counts of total coliforms, Escherichia coli, and Clostridium perfringens in feces were not affected by diet, but Bifidobacteria spp. counts were lower (P < 0.05) in pigs fed the yeast + acid diet and lactobacilli counts were higher (P < 0.05) in pigs fed yeast. Fecal pH and VFA concentrations and intestinal morphological traits were not consistently affected by diet. Serum IgG levels were elevated in the yeast + acid (P < 0.01) group. In Exp. 2, the effects of yeast and carbadox additions to the diet on enteric microbial populations in young pigs housed in isolation units were evaluated. Pigs (n = 24) were weaned at 11 d of age (4.1 kg BW) and placed in isolation chambers (two pigs per chamber) equipped with individual air filtering systems and excrement containers. Treatments were a nonmedicated basal diet and the basal diet with 55 mg/kg of carbadox or with 3% yeast. Diets were fed for 29 d, then each pig was orally dosed with approximately 9.5 x 10(8) CFU of E. coli K88. Daily fecal E. coli K88 counts were not different (P > 0.05) among treatments, but fecal shedding of carbadox-resistant coliforms was higher (P < 0.01) during the 9-d period in pigs fed carbadox. Total fecal coliforms were consistently lower throughout the postinoculation period in pigs fed yeast (P < 0.05). Yeast reduced colonization oftotal coliforms in the duodenum,jejunum, cecum, and colon, but it did not have a consistent effect on colonization of E. coli K88. Pigs fed yeast tended (P < 0.10) to have higher serum IgG levels than controls. In these experiments, brewers dried yeast and carbadox had minimal effects on growth, microbial populations, and intestinal health traits of early-weaned pigs, but certain serum immunological traits were enhanced by feeding yeast.

Repeated pulse feeding induces functional stability in anaerobic digestion.

PubMed

De Vrieze, Jo; Verstraete, Willy; Boon, Nico

2013-07-01

Anaerobic digestion is an environmental key technology in the future bio-based economy. To achieve functional stability, a minimal microbial community diversity is required. This microbial community should also have a certain 'elasticity', i.e. the ability to rapidly adapt to suboptimal conditions or stress. In this study it was evaluated whether a higher degree of functional stability could be achieved by changing the feeding pattern, which can change the evenness, dynamics and richness of the bacterial community. The first reactor (CSTR stable ) was fed on daily basis, whereas the second reactor (CSTR dynamic ) was fed every 2 days. Average biogas production was 0.30 l CH4 l(-1) day(-1) in both reactors, although daily variation was up to four times higher in the CSTR dynamic compared with the CSTR stable during the first 50 days. Bacterial analysis revealed that this CSTR dynamic had a two times higher degree of bacterial community dynamics. The CSTR dynamic also appeared to be more tolerant to an organic shock load of 8 g COD l(-1) and ammonium levels up to 8000 mg TAN l(-1). These results suggest that the regular application of a limited pulse of organic material and/or a variation in the substrate composition might promote higher functional stability in anaerobic digestion. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Alteration of the gastrointestinal microbiota of mice by edible blue-green algae.

PubMed

Rasmussen, H E; Martínez, I; Lee, J Y; Walter, J

2009-10-01

To characterize the effect of edible blue-green algae (cyanobacteria) on the gastrointestinal microbiota of mice. C57BL/6J mice were fed a diet supplemented with 0% or 5% dried Nostoc commune, Spirulina platensis or Afanizominon flos-aquae (w/w) for 4 weeks. Molecular fingerprinting of the colonic microbiota using denaturing gradient gel electrophoresis revealed that administration of N. commune induced major alterations in colonic microbiota composition, while administration of S. platensis or A. flos-aquae had a more subtle impact. Community profile analysis revealed that administration of N. commune did not reduce microbial diversity indices of the colonic microbiota. Despite its pronounced effects on the bacterial composition in the colon, total bacterial numbers in the gut of mice fed N. commune were not reduced as assessed by quantitative real-time PCR and bacteriological culture. The results presented here show that administration of blue-green algae, and especially N. commune, alters colonic microbiota composition in mice with limited effects on total bacterial numbers or microbial diversity. Blue-green algae are consumed in many countries as a source of nutrients and to promote health, and they are intensively studied for their pharmaceutical value. Given the importance of the gut microbiota for many host functions, the effects of blue-green algae on gut microbial ecology revealed during this study should be considered when using them as food supplements or when studying their pharmaceutical properties.

A defined co-culture of Geobacter sulfurreducens and Escherichia coli in a membrane-less microbial fuel cell.

PubMed

Bourdakos, Nicholas; Marsili, Enrico; Mahadevan, Radhakrishnan

2014-04-01

Wastewater-fed microbial fuel cells (MFCs) are a promising technology to treat low-organic carbon wastewater and recover part of the chemical energy in wastewater as electrical power. However, the interactions between electrochemically active and fermentative microorganisms cannot be easily studied in wastewater-fed MFCs because of their complex microbial communities. Defined co-culture MFCs provide a detailed understanding of such interactions. In this study, we characterize the extracellular metabolites in laboratory-scale membrane-less MFCs inoculated with Geobacter sulfurreducens and Escherichia coli co-culture and compare them with pure culture MFCs. G. sulfurreducens MFCs are sparged to maintain anaerobic conditions, while co-culture MFCs rely on E. coli for oxygen removal. G. sulfurreducens MFCs have a power output of 128 mW m(-2) , compared to 63 mW m(-2) from the co-culture MFCs. Analysis of metabolites shows that succinate production in co-culture MFCs decreases current production by G. sulfurreducens and that the removal of succinate is responsible for the increased current density in the late co-culture MFCs. Interestingly, pH adjustment is not required for co-culture MFCs but a base addition is necessary for E. coli MFCs and cultures in vials. Our results show that defined co-culture MFCs provide clear insights into metabolic interactions among bacteria while maintaining a low operational complexity. © 2013 Wiley Periodicals, Inc.

Interaction between dietary lipids and gut microbiota regulates hepatic cholesterol metabolism.

PubMed

Caesar, Robert; Nygren, Heli; Orešič, Matej; Bäckhed, Fredrik

2016-03-01

The gut microbiota influences many aspects of host metabolism. We have previously shown that the presence of a gut microbiota remodels lipid composition. Here we investigated how interaction between gut microbiota and dietary lipids regulates lipid composition in the liver and plasma, and gene expression in the liver. Germ-free and conventionally raised mice were fed a lard or fish oil diet for 11 weeks. We performed lipidomics analysis of the liver and serum and microarray analysis of the liver. As expected, most of the variation in the lipidomics dataset was induced by the diet, and abundance of most lipid classes differed between mice fed lard and fish oil. However, the gut microbiota also affected lipid composition. The gut microbiota increased hepatic levels of cholesterol and cholesteryl esters in mice fed lard, but not in mice fed fish oil. Serum levels of cholesterol and cholesteryl esters were not affected by the gut microbiota. Genes encoding enzymes involved in cholesterol biosynthesis were downregulated by the gut microbiota in mice fed lard and were expressed at a low level in mice fed fish oil independent of microbial status. In summary, we show that gut microbiota-induced regulation of hepatic cholesterol metabolism is dependent on dietary lipid composition. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

Analysis of microbial community variation during the mixed culture fermentation of agricultural peel wastes to produce lactic acid.

PubMed

Liang, Shaobo; Gliniewicz, Karol; Gerritsen, Alida T; McDonald, Armando G

2016-05-01

Mixed cultures fermentation can be used to convert organic wastes into various chemicals and fuels. This study examined the fermentation performance of four batch reactors fed with different agricultural (orange, banana, and potato (mechanical and steam)) peel wastes using mixed cultures, and monitored the interval variation of reactor microbial communities with 16S rRNA genes using Illumina sequencing. All four reactors produced similar chemical profile with lactic acid (LA) as dominant compound. Acetic acid and ethanol were also observed with small fractions. The Illumina sequencing results revealed the diversity of microbial community decreased during fermentation and a community of largely lactic acid producing bacteria dominated by species of Lactobacillus developed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Soil microbial community response to corn stover harvesting under rain-fed, no-till conditions at multiple U.S. locations

USDA-ARS?s Scientific Manuscript database

Harvesting of corn stover for cellulosic ethanol production must be balanced with the requirement for returning plant residues to agricultural fields to maintain soil structure, fertility, crop protection, and other ecosystem services. High rates of corn stover removal can be associated with decrea...

Effects of feeding Mediterranean buffalo sorghum silage versus maize silage on the rumen microbiota and milk fatty acid content.

PubMed

Ann Huws, Sharon; Chiariotti, Antonella; Sarubbi, Fiorella; Carfì, Francesca; Pace, Vilma

2012-01-01

Sorghum presents a sustainable feedstock for Mediterranean buffaloes due to its reduced water and nitrogen requirements compared with maize, which is currently fed primarily. We investigated the effects of feeding sorghum as opposed to maize on Mediterranean buffalo rumen microbial diversity and milk fatty acid content. Four cannulated lactating Mediterranean buffalo cows were fed a basal diet for one month before switching either to maize or sorghum-silage based diets for a 3-month period. Buffaloes were then changed over to the contrasting diet for a further one month. Rumen and milk samples were collected at the end of each month. DGGE- and T-RFLP-based dendrograms generated from rumen samples did not show an effect of diet on rumen bacterial diversity. Milk samples also did not differ in terms of their fatty acid content post sorghum feeding as compared with maize feeding. Thus, sorghum provides an environmentally beneficial alternative to maize for feeding Mediterranean buffalo with little effect on rumen microbial diversity or milk fatty acid composition compared with maize feeding.

Urea recycling contributes to nitrogen retention in calves fed milk replacer and low-protein solid feed.

PubMed

Berends, Harma; van den Borne, Joost J G C; Røjen, Betina A; van Baal, Jürgen; Gerrits, Walter J J

2014-07-01

Urea recycling, with urea originating from catabolism of amino acids and hepatic detoxification of ammonia, is particularly relevant for ruminant animals, in which microbial protein contributes substantially to the metabolizable protein supply. However, the quantitative contribution of urea recycling to protein anabolism in calves during the transition from preruminants (milk-fed calves) to ruminants [solid feed (SF)-fed calves] is unknown. The aim of this study was to quantify urea recycling in milk-fed calves when provided with low-protein SF. Forty-eight calves [164 ± 1.6 kg body weight (BW)] were assigned to 1 of 4 SF levels [0, 9, 18, and 27 g of dry matter (DM) SF · kg BW(-0.75) · d⁻¹] provided in addition to an identical amount of milk replacer. Urea recycling was quantified after a 24-h intravenous infusion of [¹⁵N₂]urea by analyzing urea isotopomers in 68-h fecal and urinary collections. Real-time qPCR was used to measure gene expression levels of bovine urea transporter B (bUTB) and aquaglyceroporin-3 and aquaglyceroporin-7 in rumen wall tissues. For every incremental gram of DM SF intake (g DM · kg(0.75)), nitrogen intake increased by 0.70 g, and nitrogen retention increased by 0.55 g (P < 0.01). Of this increase in nitrogen retention, 19% could be directly explained by urea recycling. Additionally, part of the observed increase in nitrogen retention could be explained by the extra protein provided by the SF and likely by a greater efficiency of postabsorptive use of nitrogen for gain. Ruminal bUTB abundance increased (P < 0.01) with SF provision. Aquaglyceroporin-3 expression increased (P < 0.01) with SF intake, but aquaglyceroporin-7 expression did not. We conclude that in addition to the increase in digested nitrogen, urea recycling contributes to the observed increase in nitrogen retention with increasing SF intake in milk-fed calves. Furthermore, ruminal bUTB and aquaglyceroporin-3 expression are upregulated with SF intake, which might be associated with urea recycling. © 2014 American Society for Nutrition.

Effect of different oxytetracycline addition methods on its degradation behavior in soil.

PubMed

Chen, Gui-Xiu; He, Wei-Wei; Wang, Yan; Zou, Yong-De; Liang, Juan-Boo; Liao, Xin-Di; Wu, Yin-Bao

2014-05-01

The degradation behavior of veterinary antibiotics in soil is commonly studied using the following methods of adding antibiotics to the soil: (i) adding manure collected from animals fed with a diet containing antibiotics, (ii) adding antibiotic-free animal manure spiked with antibiotics and (iii) directly adding antibiotics. No research simultaneously comparing different antibiotic addition methods was found. Oxytetracycline (OTC) was used as a model antibiotic to compare the effect of the three commonly used antibiotic addition methods on OTC degradation behavior in soil. The three treatment methods have similar trends, though OTC degradation half-lives show the following significant differences (P<0.05): manure from swine fed OTC (treatment A)

Relationship between dissolved organic matter quality and microbial community composition across polar glacial environments.

PubMed

Smith, H J; Dieser, M; McKnight, D M; SanClements, M D; Foreman, C M

2018-05-14

Vast expanses of Earth's surface are covered by ice, with microorganisms in these systems affecting local and global biogeochemical cycles. We examined microbial assemblages from habitats fed by glacial meltwater within the McMurdo Dry Valleys, Antarctica, and on the west Greenland Ice Sheet, (GrIS) evaluating potential physicochemical factors explaining trends in community structure. Microbial assemblages present in the different Antarctic dry valley habitats were dominated by Sphingobacteria and Flavobacteria, while Gammaproteobacteria and Sphingobacteria prevailed in west GrIS supraglacial environments. Microbial assemblages clustered by location (Canada Glacier, Cotton Glacier, west GrIS) and were separated by habitat type (i.e. ice, cryoconite holes, supraglacial lakes, sediment, and stream water). Community dissimilarities were strongly correlated with dissolved organic matter (DOM) quality. Microbial meltwater assemblages were most closely associated with different protein-like components of the DOM pool. Microbes in environments with mineral particles (i.e. stream sediments, cryoconite holes) were linked to DOM containing more humic-like fluorescence. Our results demonstrate the establishment of distinct microbial communities within ephemeral glacial meltwater habitats, with DOM-microbe interactions playing an integral role in shaping communities on local and polar spatial scales.

Effects of the Dietary Protein and Carbohydrate Ratio on Gut Microbiomes in Dogs of Different Body Conditions

PubMed Central

Lauber, Christian L.; Czarnecki-Maulden, Gail; Pan, Yuanlong; Hannah, Steven S.

2017-01-01

ABSTRACT Obesity has become a health epidemic in both humans and pets. A dysbiotic gut microbiota has been associated with obesity and other metabolic disorders. High-protein, low-carbohydrate (HPLC) diets have been recommended for body weight loss, but little is known about their effects on the canine gut microbiome. Sixty-three obese and lean Labrador retrievers and Beagles (mean age, 5.72 years) were fed a common baseline diet for 4 weeks in phase 1, followed by 4 weeks of a treatment diet, specifically, the HPLC diet (49.4% protein, 10.9% carbohydrate) or a low-protein, high-carbohydrate (LPHC) diet (25.5% protein, 38.8% carbohydrate) in phase 2. 16S rRNA gene profiling revealed that dietary protein and carbohydrate ratios have significant impacts on gut microbial compositions. This effect appeared to be more evident in obese dogs than in lean dogs but was independent of breed. Consumption of either diet increased the bacterial evenness, but not the richness, of the gut compared to that after consumption of the baseline diet. Macronutrient composition affected taxon abundances, mainly within the predominant phyla, Firmicutes and Bacteroidetes. The LPHC diet appeared to favor the growth of Bacteroides uniformis and Clostridium butyricum, while the HPLC diet increased the abundances of Clostridium hiranonis, Clostridium perfringens, and Ruminococcus gnavus and enriched microbial gene networks associated with weight maintenance. In addition, we observed a decrease in the Bacteroidetes to Firmicutes ratio and an increase in the Bacteroides to Prevotella ratio in the HPLC diet-fed dogs compared to these ratios in dogs fed other diets. Finally, analysis of the effect of diet on the predicted microbial gene network was performed using phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt). PMID:28119466

The microbiological safety of duckweed fed chickens: a risk assessment of using duckweed reared on domestic wastewater as a protein source in broiler chickens

NASA Astrophysics Data System (ADS)

Moyo, S.; Dalu, J. M.; Ndamba, J.

The possibility of transmission of pathogens from duckweed supplemented feed to chickens and consequently to the human consumer necessitated the microbiological testing of duckweed fed chickens. This assessment was thus done to determine whether there is transmission of pathogens from the duckweed supplemented feed to the chickens; determine whether such infection would be systemic or be confined to the gastro-intestinal tract of the birds; and to investigate the microbial load and distribution of the microbes with age. The study birds were sacrificed at 3, 6, 8 and 10 weeks of age and examined for the indicator organisms Escherichia coli and Salmonella spp. There was no discernible pattern in the microbial load of both the duckweed fed chickens and control birds with age although the control birds sampled clearly had a lower microbial load than the experimental flock. Some Salmonella and two enteropathogenic E. coli strains were isolated from control and experimental sub-samples at 3 weeks. There were no Salmonellae isolated in the subsequent batches of birds and feed although a number of E. coli were isolated. More isolates were obtained from the three weeks’ sub-samples (collected during wet weather) than from all the other sub-samples. The use of duckweed at this inclusion rate under the processing conditions at Nemanwa was thus concluded to be microbiologically safe as long as due caution is exercised during the processing of the duckweed and handling of the birds. There are indications that the chickens may get contaminated especially during wet weather as evidenced by the isolation of E. coli and Salmonella spp from the first batch sub-samples. This was attributed to poor environmental sanitation at the plant particularly in view of the prevailing wet conditions at the time.

Deep Illumina-Based Shotgun Sequencing Reveals Dietary Effects on the Structure and Function of the Fecal Microbiome of Growing Kittens

PubMed Central

Deusch, Oliver; O’Flynn, Ciaran; Colyer, Alison; Morris, Penelope; Allaway, David; Jones, Paul G.; Swanson, Kelly S.

2014-01-01

Background Previously, we demonstrated that dietary protein:carbohydrate ratio dramatically affects the fecal microbial taxonomic structure of kittens using targeted 16S gene sequencing. The present study, using the same fecal samples, applied deep Illumina shotgun sequencing to identify the diet-associated functional potential and analyze taxonomic changes of the feline fecal microbiome. Methodology & Principal Findings Fecal samples from kittens fed one of two diets differing in protein and carbohydrate content (high–protein, low–carbohydrate, HPLC; and moderate-protein, moderate-carbohydrate, MPMC) were collected at 8, 12 and 16 weeks of age (n = 6 per group). A total of 345.3 gigabases of sequence were generated from 36 samples, with 99.75% of annotated sequences identified as bacterial. At the genus level, 26% and 39% of reads were annotated for HPLC- and MPMC-fed kittens, with HPLC-fed cats showing greater species richness and microbial diversity. Two phyla, ten families and fifteen genera were responsible for more than 80% of the sequences at each taxonomic level for both diet groups, consistent with the previous taxonomic study. Significantly different abundances between diet groups were observed for 324 genera (56% of all genera identified) demonstrating widespread diet-induced changes in microbial taxonomic structure. Diversity was not affected over time. Functional analysis identified 2,013 putative enzyme function groups were different (p<0.000007) between the two dietary groups and were associated to 194 pathways, which formed five discrete clusters based on average relative abundance. Of those, ten contained more (p<0.022) enzyme functions with significant diet effects than expected by chance. Six pathways were related to amino acid biosynthesis and metabolism linking changes in dietary protein with functional differences of the gut microbiome. Conclusions These data indicate that feline feces-derived microbiomes have large structural and functional differences relating to the dietary protein:carbohydrate ratio and highlight the impact of diet early in life. PMID:25010839

Effects of zinc oxide and microbial phytase on digestibility of calcium and phosphorus in maize-based diets fed to growing pigs.

PubMed

Blavi, L; Sola-Oriol, D; Perez, J F; Stein, H H

2017-02-01

An experiment was conducted to test the hypothesis that inclusion of Zn at a pharmacological level in diets fed to pigs affects apparent total tract digestibility (ATTD) of Ca and P and standardized total tract digestibility (STTD) of Ca. The second hypothesis was that inclusion of microbial phytase increases the ATTD of Ca and P and the STTD of Ca regardless of the concentration of Zn in the diet. Fifty-six growing barrows (15.4 ± 1.9 kg average BW) were allotted to a randomized complete block design with 7 dietary treatments and 8 pigs per treatment. A maize-based basal diet was formulated with either 0 or 2,400 mg/kg Zn from ZnO and 0, 1,000, or 3,000 units of phytase (FTU) per kilogram. A Ca-free diet was used to determine basal endogenous losses of Ca. Experimental diets were fed for 13 d, and feces were collected from the feed provided from d 6 to 11 using the marker-to-marker approach; urine was also collected from d 6 to 11. Retention of Ca, ATTD of Ca, and STTD of Ca increased ( < 0.01) as the concentration of phytase in the diet increased and were less ( < 0.01) if ZnO was used than if no ZnO was added to the diet. Retention of P and the ATTD of P increased ( < 0.0001) as the concentration of phytase increased in the diet, but the increase was greater if ZnO was not added than if ZnO was added to the diet (interaction, < 0.05). In conclusion, pharmacological levels of Zn reduced Ca and P digestibility and retention, but this effect was partly ameliorated by the inclusion of phytase in the diets. Inclusion of microbial phytase increased the ATTD and STTD of Ca in diets and also the ATTD of P.

Microbial Composition and In Vitro Fermentation Patterns of Human Milk Oligosaccharides and Prebiotics Differ between Formula-Fed and Sow-Reared Piglets123

PubMed Central

Li, Min; Bauer, Laura L.; Chen, Xin; Wang, Mei; Kuhlenschmidt, Theresa B.; Kuhlenschmidt, Mark S.; Fahey, George C.; Donovan, Sharon M.

2012-01-01

The microbial composition and in vitro fermentation characteristics of human milk oligosaccharides (HMO), lacto-N-neotetraose (LNnT), a 2:1 mixture of polydextrose (PDX) and galactooligosaccharides (GOS), and short-chain fructooligosaccharides (scFOS) by pooled ascending colonic microbiota from 9- and 17-d-old formula-fed (FF) and sow-reared (SR) piglets were assessed. pH change and gas, SCFA, and lactate production were determined after 0, 2, 4, 8, and 12 h of incubation. In most donor groups, the pH change was greater for scFOS fermentation and lower for PDX/GOS than for other substrates. LNnT fermentation produced larger amounts of gas, total SCFA, acetate, and butyrate than did the other substrates, whereas HMO and scFOS produced higher amounts of propionate and lactate, respectively. In general, pH change, total SCFA, acetate, and propionate production were greater in pooled inoculum from FF and 9-d-old piglets, whereas SR-derived inoculum produced higher amounts of butyrate and lactate after 4 h fermentation. Gut microbiota were assessed by 16S ribosomal RNA V3 gene denaturing gradient gel electrophoresis analysis and real-time qPCR. Microbial structures differed among the 4 groups before fermentation, with higher counts of Bifidobacterium in SR piglets and higher counts of Clostridium cluster IV, XIVa, and Bacteroides vulgatus in FF piglets. Lactobacillus counts were higher in 9-d-old piglets than in 17-d-old piglets, regardless of diet. Bifidobacterium, Bacteroides, and clostridial species increased after 8 and 12 h fermentation on most substrates. In summary, piglet diet and age affect gut microbiota, leading to different fermentation patterns. HMO have potential prebiotic effects due to their effects on SCFA production and microbial modulation. PMID:22399522

Microbial composition and in vitro fermentation patterns of human milk oligosaccharides and prebiotics differ between formula-fed and sow-reared piglets.

PubMed

Li, Min; Bauer, Laura L; Chen, Xin; Wang, Mei; Kuhlenschmidt, Theresa B; Kuhlenschmidt, Mark S; Fahey, George C; Donovan, Sharon M

2012-04-01

The microbial composition and in vitro fermentation characteristics of human milk oligosaccharides (HMO), lacto-N-neotetraose (LNnT), a 2:1 mixture of polydextrose (PDX) and galactooligosaccharides (GOS), and short-chain fructooligosaccharides (scFOS) by pooled ascending colonic microbiota from 9- and 17-d-old formula-fed (FF) and sow-reared (SR) piglets were assessed. pH change and gas, SCFA, and lactate production were determined after 0, 2, 4, 8, and 12 h of incubation. In most donor groups, the pH change was greater for scFOS fermentation and lower for PDX/GOS than for other substrates. LNnT fermentation produced larger amounts of gas, total SCFA, acetate, and butyrate than did the other substrates, whereas HMO and scFOS produced higher amounts of propionate and lactate, respectively. In general, pH change, total SCFA, acetate, and propionate production were greater in pooled inoculum from FF and 9-d-old piglets, whereas SR-derived inoculum produced higher amounts of butyrate and lactate after 4 h fermentation. Gut microbiota were assessed by 16S ribosomal RNA V3 gene denaturing gradient gel electrophoresis analysis and real-time qPCR. Microbial structures differed among the 4 groups before fermentation, with higher counts of Bifidobacterium in SR piglets and higher counts of Clostridium cluster IV, XIVa, and Bacteroides vulgatus in FF piglets. Lactobacillus counts were higher in 9-d-old piglets than in 17-d-old piglets, regardless of diet. Bifidobacterium, Bacteroides, and clostridial species increased after 8 and 12 h fermentation on most substrates. In summary, piglet diet and age affect gut microbiota, leading to different fermentation patterns. HMO have potential prebiotic effects due to their effects on SCFA production and microbial modulation.

Effect of shear on performance and microbial ecology of continuously stirred anaerobic digesters treating animal manure.

PubMed

Hoffmann, Rebecca A; Garcia, Marcelo L; Veskivar, Mehul; Karim, Khursheed; Al-Dahhan, Muthanna H; Angenent, Largus T

2008-05-01

We determined the effect of different mixing intensities on the performance, methanogenic population dynamics, and juxtaposition of syntrophic microbes in anaerobic digesters treating cow manure from a dairy farm. Computer automated radioactive particle tracking in conjunction with computational fluid dynamics was performed to quantify the shear levels locally. Four continuously stirred anaerobic digesters were operated at different mixing intensities of 1,500, 500, 250, and 50 revolutions per min (RPM) over a 260-day period at a temperature of 34 +/- 1 degrees C. Animal manure at a volatile solids (VS) concentration of 50 g/L was fed into the digesters daily at five different organic loading rates between 0.6 and 3.5 g VS/L day. The different mixing intensities had no effect on the biogas production rates and yields at steady-state conditions. A methane yield of 0.241 +/- 0.007 L CH(4)/g VS fed was obtained by pooling the data of all four digesters during steady-state periods. However, digester performance was affected negatively by mixing intensity during startup of the digesters, with lower biogas production rates and higher volatile fatty acids concentrations observed for the 1,500-RPM digester. Despite similar methane production yields and rates, the acetoclastic methanogenic populations were different for the high- and low-intensity mixed digesters with Methanosarcina spp. and Methanosaeta concilii as the predominant methanogens, respectively. For all four digesters, epifluorescence microscopy revealed decreasing microbial floc sizes beginning at week 4 and continuing through week 26 after which no microbial flocs remained. This decrease in size, and subsequent loss of microbial flocs did not, however, produce any long-term upsets in digester performance. Copyright 2007 Wiley Periodicals, Inc.

Intestinal microbiota in infants at high risk for allergy: Effects of prebiotics and role in eczema development.

PubMed

Wopereis, Harm; Sim, Kathleen; Shaw, Alexander; Warner, John O; Knol, Jan; Kroll, J Simon

2018-04-01

Development of the gut microbiota in infancy is important in maturation of the immune system. Deviations in colonization patterns have been associated with allergic manifestations such as eczema, but exact microbiome dysfunctions underlying allergies remain unclear. We studied the gut microbiota of 138 infants at increased risk of allergy, participating in a clinical trial investigating the effectiveness of a partially hydrolyzed protein formula supplemented with nondigestible oligosaccharides on the prevention of eczema. The effects of interventions and breast-feeding on fecal microbiota were investigated. Additionally, we aimed to identify microbial patterns associated with the onset of eczema. Bacterial taxonomic compositions in the first 26 weeks of life were analyzed by using 16S rRNA gene sequencing. Additionally, fecal pH and microbial metabolite levels were measured. Fecal microbial composition, metabolites, and pH of infants receiving partially hydrolyzed protein formula supplemented with nondigestible oligosaccharides was closer to that of breast-fed infants than that of infants receiving standard cow's milk formula. Infants with eczema by 18 months showed discordant development of bacterial genera of Enterobacteriaceae and Parabacteroides species in the first 26 weeks, as well as decreased acquisition of lactate-utilizing bacteria producing butyrate, namely Eubacterium and Anaerostipes species, supported by increased lactate and decreased butyrate levels. We showed that a partially hydrolyzed protein infant formula with specific prebiotics modulated the gut microbiota closer to that of breast-fed infants. Additionally, we identified a potential link between microbial activity and onset of eczema, which might reflect a suboptimal implementation of gut microbiota at specific developmental stages in infants at high risk for allergy. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Quantitative fluorescent in-situ hybridization: a hypothesized competition mode between two dominant bacteria groups in hydrogen-producing anaerobic sludge processes.

PubMed

Huang, C-L; Chen, C-C; Lin, C-Y; Liu, W-T

2009-01-01

Two hydrogen-producing continuous flow stirred tank reactors (CSTRs) fed respectively with glucose and sucrose were investigated by polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE) and fluorescent in-situ hybridization (FISH). The substrate was fed in a continuous mode decreased from hydraulic retention time (HRT) 10 hours to 6, 5, 4, 3, and 2 hours. Quantitative fluorescent in-situ hybridization (FISH) observations further demonstrated that two morphotypes of bacteria dominated both microbial communities. One was long rod bacteria which can be targeted either by Chis150 probe designed to hybridize the gram positive low G + C bacteria or the specific oligonucleotide probe Lg10-6. The probe Lg10-6, affiliated with Clostridium pasteurianum, was designed and then checked with other reference organisms. The other type, unknown group, which cannot be detected by Chis150 was curved rod bacteria. Notably, the population ratios of the two predominant groups reflected the different operational performance of the two reactors, such as hydrogen producing rates, substrate turnover rates and metabolites compositions. Therefore, a competition mode of the two dominant bacteria groups was hypothesized. In the study, 16S rRNA-based gene library of hydrogen-producing microbial communities was established. The efficiency of hydrogen yields was correlated with substrates (glucose or sucrose), HRT, metabolites compositions (acetate, propionate, butyrate and ethanol), thermal pre-treatment (seed biomass was heated at 100 degrees C for 45 minutes), and microbial communities in the bioreactor, not sludge sources (municipal sewage sludge, alcohol-processing sludge, or bean-processing sludge). The designed specific oligonucleotide probe Lg10-6 also provides us a useful and fast molecular tool to screen hydrogen-producing microbial communities in the future research.

Effects of purified lignin and mannan oligosaccharides on intestinal integrity and microbial populations in the ceca and litter of broiler chickens.

PubMed

Baurhoo, B; Phillip, L; Ruiz-Feria, C A

2007-06-01

A study was conducted to evaluate lignin and mannan oligosaccharides as potential alternatives to antibiotic growth promoters in broilers. Dietary treatments included an antibiotic-free diet (CTL-), a positive control (CTL+, 11 mg/kg of virginiamycin), and an antibiotic-free diet containing BioMos (MOS, 0.2% to 21 d and 0.1% thereafter) or Alcell lignin at 1.25% (LL) or 2.5% (HL) of the diet. Each treatment was randomly assigned to 4 floor pen replicates (40 birds each). Body weight and feed conversion were recorded weekly throughout 42 d. Jejunum histology was analyzed at d 14, 28, and 42. At d 28 and 42, cecal contents were assayed for Escherichia coli, Salmonella, lactobacilli, and bifidobacteria, and the litter was analyzed for E. coli and Salmonella. Birds fed the CTL- diet were heavier (P<0.05) than those fed the other dietary treatments, but feed conversion was not affected by dietary treatments. Birds fed MOS and LL had increased jejunum villi height and a higher number of goblet cells per villus (P<0.05) when compared with those fed the CTL+ diet. At d 42, birds fed MOS, LL, or HL had greater lactobacilli numbers than those fed the CTL+ diet. Compared with the CTL+ diet, the MOS diet increased the populations of bifidobacteria (P<0.05) in the ceca. Litter E. coli load was lower in birds fed MOS (P<0.05) than in birds fed the CTL+ diet but comparable to that of birds fed the LL or HL diet. Broiler performance was similar in birds fed antibiotics or antibiotic-free diets containing either MOS or lignin. However, birds fed MOS and LL had a comparative advantage over birds fed antibiotics as evidenced by an increased population of beneficial bacteria in the ceca, increased villi height and number of goblet cells in the jejunum, and lower population of E. coli in the litter.

Ground Juniperus pinchotii and urea in supplements fed to Rambouillet ewe lambs Part 2: Ewe lamb rumen microbial communities.

PubMed

Ishaq, S L; Yeoman, C J; Whitney, T R

2017-10-01

This study evaluated effects of ground redberry juniper () and urea in dried distillers grains with solubles-based supplements fed to Rambouillet ewe lambs ( = 48) on rumen physiological parameters and bacterial diversity. In a randomized study (40 d), individually-penned lambs were fed ground sorghum-sudangrass hay and of 1 of 8 supplements (6 lambs/treatment; 533 g/d; as-fed basis) in a 4 × 2 factorial design with 4 concentrations of ground juniper (15%, 30%, 45%, or 60% of DM) and 2 levels of urea (1% or 3% of DM). Increasing juniper resulted in minor changes in microbial β-diversity (PERMANOVA, pseudo F = 1.33, = 0.04); however, concentrations of urea did not show detectable broad-scale differences at phylum, family, or genus levels according to ANOSIM ( > 0.05), AMOVA ( > 0.10), and PERMANOVA ( > 0.05). Linear discriminant analysis indicated some genera were specific to certain dietary treatments ( < 0.05), though none of these genera were present in high abundance; high concentrations of juniper were associated with and , low concentrations of urea were associated with , and high concentrations of urea were associated with and . were decreased by juniper and urea. , , and increased with juniper and were positively correlated (Spearman's, < 0.05) with each other but not to rumen factors, suggesting a symbiotic interaction. Overall, there was not a juniper × urea interaction for total VFA, VFA by concentration or percent total, pH, or ammonia ( 0.29). When considering only percent inclusion of juniper, ruminal pH and proportion of acetic acid linearly increased ( < 0.001) and percentage of butyric acid linearly decreased ( = 0.009). Lamb ADG and G:F were positively correlated with (Spearman's, < 0.05) and negatively correlated with Synergistaceae, the BS5 group, and Lentisphaerae. Firmicutes were negatively correlated with serum urea nitrogen, ammonia, total VFA, total acetate, and total propionate. Overall, modest differences in bacterial diversity among treatments occurred in the abundance or evenness of several OTUs, but there was not a significant difference in OTU richness. As diversity was largely unchanged, the reduction in ADG and lower-end BW was likely due t* reduced DMI rather than a reduction in microbial fermentative ability.

Nutrient utilization, ruminal fermentation, microbial abundances, and milk yield and composition in dairy goats fed diets including tomato and cucumber waste fruits.

PubMed

Romero-Huelva, M; Ramos-Morales, E; Molina-Alcaide, E

2012-10-01

The effects of replacing 35% of cereals-based concentrate with feed blocks (FB) containing waste fruits of tomato, cucumber, or barley grain in diets for lactating goats on nutrient utilization, ruminal fermentation, microbial N flow to the duodenum, milk yield and quality, methane emissions, and abundances of total bacteria and methanogens were studied. Eight Murciano-Granadina goats (39.4 ± 5.39 kg of body weight, mean ± SD) in the middle of the third lactation were used and 4 diets were studied in a replicated 4×4 Latin square experimental design. Diets consisted of alfalfa hay (A) plus concentrate (C) in a 1:1 ratio (diet AC) or diets in which 35% of the concentrate was replaced with FB including wastes of tomato fruit, cucumber, or barley. In each period, 2 goats were randomly assigned to 1 of the dietary treatments. Intakes of FB including tomato, cucumber, and barley were 208 ± 65, 222 ± 52, and 209 ± 83 g of dry matter per animal and day, respectively. The replacement of 35% of concentrate with FB did not compromise nutrient apparent digestibility, total purine derivative urinary excretion, milk yield and composition, and total bacteria and methanogen abundances. Digestible energy and that in methane and urine were higher for AC than for FB-containing diets, whereas the metabolizable energy value was not affected by diet. The inclusion of tomato and cucumber fruits in FB decreased N in urine and CH(4) emissions compared with AC, which is environmentally relevant. However, tomato-based FB decreased microbial N flow in the rumen, whereas goats fed cucumber-based FB had the highest values for this measurement. Moreover, FB containing barley or tomato and cucumber led to lower rumen volatile fatty acid and NH(3)-N concentrations, respectively. Milk from goats fed diets including tomato and cucumber-based FB had higher linoleic, linolenic, and total polyunsaturated fatty acid concentrations than that from goats fed AC. Overall, our study suggests that tomato and cucumber FB could replace 35% of the concentrate in the dairy goat diet, reducing animal feeding cost and methane production, leading to higher polyunsaturated fatty acid proportions in milk, and without compromising nutrient utilization or milk yield. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Characterisation of microbial biocoenosis in vertical subsurface flow constructed wetlands.

PubMed

Tietz, Alexandra; Kirschner, Alexander; Langergraber, Günter; Sleytr, Kirsten; Haberl, Raimund

2007-07-15

In this study a quantitative description of the microbial biocoenosis in subsurface vertical flow constructed wetlands fed with municipal wastewater was carried out. Three different methods (substrate induced respiration, ATP measurement and fumigation-extraction) were applied to measure the microbial biomass at different depths of planted and unplanted systems. Additionally, bacterial biomass was determined by epifluorescence microscopy and productivity was measured via (14)C leucine incorporation into bacterial biomass. All methods showed that >50% of microbial biomass and bacterial activity could be found in the first cm and about 95% in the first 10 cm of the filter layer. Bacterial biomass in the first 10 cm of the filter body accounted only for 16-19% of the total microbial biomass. Whether fungi or methodical uncertainties are mainly responsible for the difference between microbial and bacterial biomass remains to be examined. A comparison between the purification performance of planted and unplanted pilot-scale subsurface vertical flow constructed wetlands (PSCWs) showed no significant difference with the exception of the reduction of enterococci. The microbial biomass in all depths of the filter body was also not different in planted and unplanted systems. Compared with data from soils the microbial biomass in the PSCWs was high, although the specific surface area of the used sandy filter material available for biofilm growth was lower, especially in the beginning of the set-up of the PSCWs, due to missing clay and silt fraction.

Comparative analysis of microbial community of novel lactic acid fermentation inoculated with different undefined mixed cultures.

PubMed

Liang, Shaobo; Gliniewicz, Karol; Mendes-Soares, Helena; Settles, Matthew L; Forney, Larry J; Coats, Erik R; McDonald, Armando G

2015-03-01

Three undefined mixed cultures (activated sludge) from different municipal wastewater treatment plants were used as seeds in a novel lactic acid fermentation process fed with potato peel waste (PPW). Anaerobic sequencing batch fermenters were run under identical conditions to produce predominantly lactic acid. Illumina sequencing was used to examine the 16S rRNA genes of bacteria in the three seeds and fermenters. Results showed that the structure of microbial communities of three seeds were different. All three fermentation products had unique community structures that were dominated (>96%) by species of the genus Lactobacillus, while members of this genus constituted <0.1% in seeds. The species of Lactobacillus sp. differed among the three fermentations. Results of this study suggest the structure of microbial communities in lactic acid fermentation of PPW with undefined mixed cultures were robust and resilient, which provided engineering prospects for the microbial utilization of carbohydrate wastes to produce lactic acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

Food safety issues: a summary report of a panel session addressing pre- and post-harvest strategies to improve public health.

PubMed

Kirkhorn, Steven R

2008-01-01

The paper presents a summary of a panel presentation by animal scientists and public health veterinarians on food safety methods to improve public health of the public consuming beef and poultry. Pre-harvest methods discussed include vaccination to decrease shedding of Esherichia coli O157:H7, direct-fed microbials (DFMs), calving methods, and responsible use of antimicrobials. Post-harvest methods discussed include increased sampling and use of hazard analysis and critical control point (HACCP) methods, test-and-hold of meat products prior to release for public consumption, development of attainment categories, the use of pulsed field gel electrophoresis (PFGE) for genotyping and serotyping, and an 11-step surveillance program. The public health concern and financial consequences of contamination with E. coli O157:H7 is discussed. A "carrot and stick" approach for both producers and processors to increase vaccination and product testing is recommended.

Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls

DOE PAGES

Kallenbach, Cynthia M.; Frey, Serita D.; Grandy, A. Stuart

2016-11-28

Soil organic matter (SOM) and the carbon and nutrients therein drive fundamental submicron- to global-scale biogeochemical processes and influence carbon-climate feedbacks. Consensus is emerging that microbial materials are an important constituent of stable SOM, and new conceptual and quantitative SOM models are rapidly incorporating this view. However, direct evidence demonstrating that microbial residues account for the chemistry, stability and abundance of SOM is still lacking. Further, emerging models emphasize the stabilization of microbial-derived SOM by abiotic mechanisms, while the effects of microbial physiology on microbial residue production remain unclear. Here we provide the first direct evidence that soil microbes producemore » chemically diverse, stable SOM. As a result, we show that SOM accumulation is driven by distinct microbial communities more so than clay mineralogy, where microbial-derived SOM accumulation is greatest in soils with higher fungal abundances and more efficient microbial biomass production.« less

Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kallenbach, Cynthia M.; Frey, Serita D.; Grandy, A. Stuart

Soil organic matter (SOM) and the carbon and nutrients therein drive fundamental submicron- to global-scale biogeochemical processes and influence carbon-climate feedbacks. Consensus is emerging that microbial materials are an important constituent of stable SOM, and new conceptual and quantitative SOM models are rapidly incorporating this view. However, direct evidence demonstrating that microbial residues account for the chemistry, stability and abundance of SOM is still lacking. Further, emerging models emphasize the stabilization of microbial-derived SOM by abiotic mechanisms, while the effects of microbial physiology on microbial residue production remain unclear. Here we provide the first direct evidence that soil microbes producemore » chemically diverse, stable SOM. As a result, we show that SOM accumulation is driven by distinct microbial communities more so than clay mineralogy, where microbial-derived SOM accumulation is greatest in soils with higher fungal abundances and more efficient microbial biomass production.« less

Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls

NASA Astrophysics Data System (ADS)

Kallenbach, Cynthia M.; Frey, Serita D.; Grandy, A. Stuart

2016-11-01

Soil organic matter (SOM) and the carbon and nutrients therein drive fundamental submicron- to global-scale biogeochemical processes and influence carbon-climate feedbacks. Consensus is emerging that microbial materials are an important constituent of stable SOM, and new conceptual and quantitative SOM models are rapidly incorporating this view. However, direct evidence demonstrating that microbial residues account for the chemistry, stability and abundance of SOM is still lacking. Further, emerging models emphasize the stabilization of microbial-derived SOM by abiotic mechanisms, while the effects of microbial physiology on microbial residue production remain unclear. Here we provide the first direct evidence that soil microbes produce chemically diverse, stable SOM. We show that SOM accumulation is driven by distinct microbial communities more so than clay mineralogy, where microbial-derived SOM accumulation is greatest in soils with higher fungal abundances and more efficient microbial biomass production.

Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls.

PubMed

Kallenbach, Cynthia M; Frey, Serita D; Grandy, A Stuart

2016-11-28

Soil organic matter (SOM) and the carbon and nutrients therein drive fundamental submicron- to global-scale biogeochemical processes and influence carbon-climate feedbacks. Consensus is emerging that microbial materials are an important constituent of stable SOM, and new conceptual and quantitative SOM models are rapidly incorporating this view. However, direct evidence demonstrating that microbial residues account for the chemistry, stability and abundance of SOM is still lacking. Further, emerging models emphasize the stabilization of microbial-derived SOM by abiotic mechanisms, while the effects of microbial physiology on microbial residue production remain unclear. Here we provide the first direct evidence that soil microbes produce chemically diverse, stable SOM. We show that SOM accumulation is driven by distinct microbial communities more so than clay mineralogy, where microbial-derived SOM accumulation is greatest in soils with higher fungal abundances and more efficient microbial biomass production.

A Novel Electrophototrophic Bacterium Rhodopseudomonas palustris Strain RP2, Exhibits Hydrocarbonoclastic Potential in Anaerobic Environments

PubMed Central

Venkidusamy, Krishnaveni; Megharaj, Mallavarapu

2016-01-01

An electrophototrophic, hydrocarbonoclastic bacterium Rhodopseudomonas palustris stain RP2 was isolated from the anodic biofilms of hydrocarbon fed microbial electrochemical remediation systems (MERS). Salient properties of the strain RP2 were direct electrode respiration, dissimilatory metal oxide reduction, spore formation, anaerobic nitrate reduction, free living diazotrophy and the ability to degrade n-alkane components of petroleum hydrocarbons (PH) in anoxic, photic environments. In acetate fed microbial electrochemical cells, a maximum current density of 305 ± 10 mA/m2 (1000Ω) was generated (power density 131.65 ± 10 mW/m2) by strain RP2 with a coulombic efficiency of 46.7 ± 1.3%. Cyclic voltammetry studies showed that anaerobically grown cells of strain RP2 is electrochemically active and likely to transfer electrons extracellularly to solid electron acceptors through membrane bound compounds, however, aerobically grown cells lacked the electrochemical activity. The ability of strain RP2 to produce current (maximum current density 21 ± 3 mA/m2; power density 720 ± 7 μW/m2, 1000 Ω) using PH as a sole energy source was also examined using an initial concentration of 800 mg l-1 of diesel range hydrocarbons (C9-C36) with a concomitant removal of 47.4 ± 2.7% hydrocarbons in MERS. Here, we also report the first study that shows an initial evidence for the existence of a hydrocarbonoclastic behavior in the strain RP2 when grown in different electron accepting and illuminated conditions (anaerobic and MERS degradation). Such observations reveal the importance of photoorganotrophic growth in the utilization of hydrocarbons from contaminated environments. Identification of such novel petrochemical hydrocarbon degrading electricigens, not only expands the knowledge on the range of bacteria known for the hydrocarbon bioremediation but also shows a biotechnological potential that goes well beyond its applications to MERS. PMID:27462307

Diet and the Intestinal Microbiome: Associations, Functions, and Implications for Health and Disease

PubMed Central

Albenberg, Lindsey G.; Wu, Gary D.

2014-01-01

The mutual relationship between the intestinal microbiota and its mammalian host is influenced by diet. Consumption of various nutrients affects the structure of the microbial community and provides substrates for microbial metabolism. The microbiota can produce small molecules that are absorbed by the host and affect many important physiological processes. Age-dependent and societal differences in the intestinal microbiota could result from differences in diet. Examples include differences in the intestinal microbiota of breast- vs formula-fed infants, or differences in microbial richness in individuals consuming an agrarian plant-based vs a Western diet, which is high in meat and fat. We review how diet affects the structure and metabolome of the human intestinal microbiome, and may contribute to health or pathogenesis of disorders such as coronary vascular disease and inflammatory bowel diseases. PMID:24503132

Investigation of extractive microbial transformation in nonionic surfactant micelle aqueous solution using response surface methodology.

PubMed

Xue, Yingying; Qian, Chen; Wang, Zhilong; Xu, Jian-He; Yang, Rude; Qi, Hanshi

2010-01-01

Extractive microbial transformation of L-phenylacetylcarbinol (L-PAC) in nonionic surfactant Triton X-100 micelle aqueous solution was investigated by response surface methodology. Based on the Box-Behnken design, a mathematical model was developed for the predication of mutual interactions between benzaldehyde, Triton X-100, and glucose on L-PAC production. It indicated that the negative or positive effect of nonionic surfactant strongly depended on the substrate concentration. The model predicted that the optimal concentration of benzaldehyde, Triton X-100, and glucose was 1.2 ml, 15 g, and 2.76 g per 100 ml, respectively. Under the optimal condition, the maximum L-PAC production was 27.6 mM, which was verified by a time course of extractive microbial transformation. A discrete fed-batch process for verification of cell activity was also presented.

Effects of dietary tannin source on performance, feed efficiency, ruminal fermentation, and carcass and non-carcass traits in steers fed a high-grain diet

USDA-ARS?s Scientific Manuscript database

Tannins are polyphenolic secondary plant compounds that have been shown to affect microbial activity to impact fermentation, protein degradation, methane production, and potential to mitigate foodborne pathogens. This study was conducted to examine the effects of source of tannin (condensed, CT, vs....

BIOAVAILABILITY AND TROPHIC TRANSFER OF HUMIC-BOUND COPPER FROM BACTERIA TO ZOOPLANKTON

EPA Science Inventory

The effect of humic acid (HA) on uptake and transfer of Cu by selected marine organisms from the microbial loop was determined. Bacteria grown to stationary phase in cultures with and without 15 ug Cu l -1 and with and without 10 mg Suwannee River Humic Acid (SRHA) l -1 were fed ...

Characterization of bovine ruminal and equine cecal microbial populations enriched for enhanced nitro-toxin metabolizing activity

USDA-ARS?s Scientific Manuscript database

The phytochemicals 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) are produced by a wide variety of leguminous plants, including over 150 different species and varieties of Astragalus. These compounds are toxic to naive grazing animals, but can be safely fed to cattle and sheep that h...

Volatile organic compound flux from manure of cattle fed diets differing in grain processing method and co-product inclusion

USDA-ARS?s Scientific Manuscript database

Odor emissions from livestock production have become increasingly important in the past decade. Odors derived from animal feeding operations are caused by odorous VOC emitted from the mixture of feces and urine, as well as feed and silage which may be experiencing microbial fermentation. Distiller...

Comparison of bacterial communities in faeces of beef cattle fed diets containing corn and wet distillers grain with solubles

USDA-ARS?s Scientific Manuscript database

Aim: The microbial ecology of feedlot Escherichia coli is poorly understood. It is a minority component of feces and must interact with many other bacteria. Use of wet distiller’s grains with solubles (WDGS) in cattle feed creates a gastrointestinal environment where some bacterial species are enri...

Quantification of the methane concentration using anaerobic oxidation of methane coupled to extracellular electron transfer

EPA Science Inventory

A biofilm anode acclimated with acetate, acetate+methane, and methane growth media for over three years produced a steady current density of 1.6-2.3 mA/m^2 in a microbial electrochemical cell (MxC) fed with methane as the sole electron donor. Geobacter was the dominant genus for...

The effects of feeding monensin on rumen microbial communities and methanogenesis in bred heifers fed in a drylot

USDA-ARS?s Scientific Manuscript database

Drylot beef cow-calf systems are viable alternative management systems to traditional forage-based systems. In such confinement, adding ionophores such as monensin to the diets of beef cattle is common, and has been shown to improve feed efficiency and increase average daily gain. The addition of mo...

Influence of a diet rich in resistant starch on the degradation of non-starch polysaccharides in the large intestine of pigs.

PubMed

Jonathan, Melliana C; Haenen, Daniëlle; Souza da Silva, Carol; Bosch, Guido; Schols, Henk A; Gruppen, Harry

2013-03-01

To investigate the effect of resistant starch to the degradation of other non-starch polysaccharides (NSPs) in the large intestine of pigs, two groups of pigs were fed either a diet containing digestible starch (DS) or a diet containing resistant starch (RS). Both diets contained NSPs from wheat and barley. Digesta from different parts of the large intestine were collected and analysed for sugar composition and carbohydrate-degrading-enzyme activities. Resistant starch, as well as β-glucans and soluble arabinoxylan, was utilised mainly in the caecum. The utilisation of β-glucans and soluble arabinoxylan in the caecum was higher in DS-fed pigs than in RS-fed pigs. Analyses on carbohydrate-degrading-enzyme activities demonstrated that microbial enzyme production was stimulated according to the diet composition, and the enzyme profile throughout the large intestine of RS-fed pigs indicated that the presence of resistant starch shifted the utilisation of NSPs to more distal parts of the colon. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of different corn processing methods on enzyme producing bacteria, protozoa, fermentation and histomorphometry of rumen in fattening lambs

PubMed Central

Gholami, Mohammad Amin; Forouzmand, Masihollah; Khajavi, Mokhtar; Hossienifar, Shima; Naghiha, Reza

2018-01-01

The purpose of this study was to investigate the effect of different corn processing methods on rumen microbial flora, histomorphometry and fermentation in fattening male lambs. Twenty male lambs (average age and weight of 90 days and 25.00 ± 1.10 kg, respectively) were used in a completely randomized design including four treatments and five replicates each over 80 days long period: 1) Lambs fed ground corn seeds; 2) Lambs fed steam-rolled corn; 3) Lambs fed soaked corn seeds (24 hr) and 4) Lambs fed soaked corn seeds (48 hr). At the end of the experiment, three lambs of each treatment were slaughtered and samples were collected for pH, volatile fatty acids, amylolytic, proteolytic, cellulytic and heterophilic bacteria and protozoa assessment. The number of proteolytic bacteria in soaked corn seeds was significantly increased in comparison with other treatments. The thickness of wall, papillae and muscular layers of rumen in the soaked corn seeds treatment was significantly increased. Overall, from a practical point of view, soaked corn processing could be generally used in lambs fattening system. PMID:29719663

Assessment of microbial viability in municipal sludge following ultrasound and microwave pretreatments and resulting impacts on the efficiency of anaerobic sludge digestion.

PubMed

Cella, Monica Angela; Akgul, Deniz; Eskicioglu, Cigdem

2016-03-01

A range of ultrasonication (US) and microwave irradiation (MW) sludge pretreatments were compared to determine the extent of cellular destruction in micro-organisms within secondary sludge and how this cellular destruction translated to anaerobic digestion (AD). Cellular lysis/inactivation was measured using two microbial viability assays, (1) Syto 16® Green and Sytox® Orange counter-assay to discern the integrity of cellular membranes and (2) a fluorescein diacetate assay to understand relative enzymatic activity. A range of MW intensities (2.17-6.48 kJ/g total solids or TS, coinciding temperatures of 60-160 °C) were selected for comparison via viability assays; a range of corresponding US intensities (2.37-27.71 kJ/g TS, coinciding sonication times of 10-60 min at different amplitudes) were also compared to this MW range. The MW pretreatment of thickened waste activated sludge (tWAS) caused fourfold to fivefold greater cell death than non-pretreated and US-pretreated tWAS. The greatest microbial destruction occurred at MW intensities greater than 2.62 kJ/g TS of sludge, after which increased energy input via MW did not appear to cause greater microbial death. In addition, the optimal MW pretreatment (80 °C, 2.62 kJ/g TS) and corresponding US pretreatment (10 min, 60 % amplitude, 2.37 kJ/g TS) were administered to the tWAS of a mixed sludge and fed to anaerobic digesters over sludge retention times (SRTs) of 20, 14, and 7 days to compare effects of feed pretreatment on AD efficiency. The digester utilizing MW-pretreated tWAS (80 °C, 2.62 kJ/g TS) had the greatest fecal coliform removal (73.4 and 69.8 % reduction, respectively), greatest solids removal (44.2 % TS reduction), and highest overall methane production (248.2 L CH4/kg volatile solids) at 14- and 7-day SRTs. However, despite the fourfold to fivefold increases in cell death upon pretreatment, improvements from the digester fed MW-pretreated sludge were marginal (i.e., increases in efficiency of less than 3-10 %) and likely due to a smaller proportion of cells (10-20 %) in the polymeric network and mixed sludge fed to digesters.

Effects of Condensed Tannins in Mao (Antidesma thwaitesianum Muell. Arg.) Seed Meal on Rumen Fermentation Characteristics and Nitrogen Utilization in Goats

PubMed Central

Gunun, P.; Wanapat, M.; Gunun, N.; Cherdthong, A.; Sirilaophaisan, S.; Kaewwongsa, W.

2016-01-01

Mao seed is a by-product of the wine and juice industry, which could be used in animal nutrition. The current study was designed to determine the effect of supplementation of mao (Antidesma thwaitesianum Muell. Arg.) seed meal (MOSM) containing condensed tannins (CT) on rumen fermentation, nitrogen (N) utilization and microbial protein synthesis in goats. Four crossbred (Thai Native×Anglo Nubian) goats with initial body weight (BW) 20±2 kg were randomly assigned to a 4×4 Latin square design. The four dietary treatments were MOSM supplementation at 0%, 0.8%, 1.6%, and 2.4% of total dry matter (DM) intake, respectively. During the experimental periods, all goats were fed a diet containing roughage to concentrate ratio of 60:40 at 3.0% BW/d and pangola grass hay was used as a roughage source. Results showed that supplementation with MOSM did not affect feed intake, nutrient intakes and apparent nutrient digestibility (p>0.05). In addition, ruminal pH and ammonia nitrogen (NH3-N) were not influenced by MOSM supplementation, whilst blood urea nitrogen was decreased quadraticly (p<0.05) in goats supplemented with MOSM at 2.4% of total DM intake. Propionate was increased linearly with MOSM supplementation, whereas acetate and butyrate were remained the same. Moreover, estimated ruminal methane (CH4) was decreased linearly (p<0.05) when goats were fed with MOSM at 1.6% and 2.4% of total DM intake. Numbers of bacteria and protozoa were similar among treatments (p>0.05). There were linear decreases in urinary N (p<0.01) and total N excretion (p<0.01) by MOSM supplementation. Furthermore, N retention was increased linearly (p<0.05) when goats were fed with MOSM supplementation at 1.6% and 2.4% of total DM intake. Microbial protein synthesis were not significantly different among treatments (p>0.05). From the current study, it can be concluded that supplementation of MOSM at 1.6% to 2.4% of total DM intake can be used to modify ruminal fermentation, especially propionate and N utilization in goats, without affecting the nutrient digestibility, microbial populations and microbial protein synthesis. PMID:26954153

The Colonic Microbiome and Epithelial Transcriptome Are Altered in Rats Fed a High-Protein Diet Compared with a Normal-Protein Diet.

PubMed

Mu, Chunlong; Yang, Yuxiang; Luo, Zhen; Guan, Leluo; Zhu, Weiyun

2016-03-01

A high-protein diet (HPD) can produce hazardous compounds and reduce butyrate-producing bacteria in feces, which may be detrimental to gut health. However, information on whether HPD affects intestinal function is limited. The aim of this study was to determine the impact of an HPD on the microbiota, microbial metabolites, and epithelial transcriptome in the colons of rats. Adult male Wistar rats were fed either a normal-protein diet (20% protein, 56% carbohydrate) or an HPD (45% protein, 30% carbohydrate) for 6 wk (n = 10 rats per group, individually fed). After 6 wk, the colonic microbiome, microbial metabolites, and epithelial transcriptome were determined. Compared with the normal-protein diet, the HPD adversely altered the colonic microbiota by increasing (P < 0.05) Escherichia/Shigella, Enterococcus, Streptococcus, and sulfate-reducing bacteria by 54.9-fold, 31.3-fold, 5.36-fold, and 2.59-fold, respectively. However, the HPD reduced Ruminococcus (8.04-fold), Akkermansia (not detected in HPD group), and Faecalibacterium prausnitzii (3.5-fold) (P < 0.05), which are generally regarded as beneficial bacteria in the colon. Concomitant increases in cadaverine (4.88-fold), spermine (31.2-fold), and sulfide (4.8-fold) (P < 0.05) and a decrease in butyrate (2.16-fold) (P < 0.05) in the HPD rats indicated an evident shift toward the production of unhealthy microbial metabolites. In the colon epithelium of the HPD rats, transcriptome analysis identified an upregulation of genes (P < 0.05) involved in disease pathogenesis; these genes are involved in chemotaxis, the tumor necrosis factor signal process, and apoptosis. The HPD was also associated with a downregulation of many genes (P < 0.05) involved in immunoprotection, such as genes involved in innate immunity, O-linked glycosylation of mucin, and oxidative phosphorylation, suggesting there may be an increased disease risk in these rats. The abundance of Escherichia/Shigella, Enterococcus, and Streptococcus was positively correlated (Spearman's ρ > 0.7, P < 0.05) with genes and metabolites generally regarded as being involved in disease pathogenesis, suggesting these bacteria may mediate the detrimental effects of HPDs on colonic health. Our findings suggest that the HPD altered the colonic microbial community, shifted the metabolic profile, and affected the host response in the colons of rats toward an increased risk of colonic disease. © 2016 American Society for Nutrition.

Cathodic reduction of hexavalent chromium [Cr(VI)] coupled with electricity generation in microbial fuel cells.

PubMed

Wang, Gang; Huang, Liping; Zhang, Yifeng

2008-11-01

A novel approach to Cr(VI)-contaminated wastewater treatment was investigated using microbial fuel cell technologies in fed-batch mode. By using synthetic Cr(VI)-containing wastewater as catholyte and anaerobic microorganisms as anodic biocatalyst, Cr(VI) at 100 mg/l was completely removed during 150 h (initial pH 2). The maximum power density of 150 mW/m(2) (0.04 mA/cm(2)) and the maximum open circuit voltage of 0.91 V were generated with Cr(VI) at 200 mg/l as electron acceptor. This work verifies the possibility of simultaneous electricity production and cathodic Cr(VI) reduction.

Correlations of fatty acid supplementation, aeroallergens, shampoo, and ear cleanser with multiple parameters in pruritic dogs.

PubMed

Nesbitt, Gene H; Freeman, Lisa M; Hannah, Steven S

2004-01-01

Seventy-two pruritic dogs were fed one of four diets controlled for n-6:n-3 fatty acid ratios and total dietary intake of fatty acids. Multiple parameters were evaluated, including clinical and cytological findings, aeroallergen testing, microbial sampling techniques, and effects of an anti-fungal/antibacterial shampoo and ear cleanser. Significant correlations were observed between many clinical parameters, anatomical sampling sites, and microbial counts when data from the diet groups was combined. There were no statistically significant differences between individual diets for any of the clinical parameters. The importance of total clinical management in the control of pruritus was demonstrated.

Co-production of bioethanol and probiotic yeast biomass from agricultural feedstock: application of the rural biorefinery concept.

PubMed

Hull, Claire M; Loveridge, E Joel; Donnison, Iain S; Kelly, Diane E; Kelly, Steven L

2014-01-01

Microbial biotechnology and biotransformations promise to diversify the scope of the biorefinery approach for the production of high-value products and biofuels from industrial, rural and municipal waste feedstocks. In addition to bio-based chemicals and metabolites, microbial biomass itself constitutes an obvious but overlooked by-product of existing biofermentation systems which warrants fuller attention. The probiotic yeast Saccharomyces boulardii is used to treat gastrointestinal disorders and marketed as a human health supplement. Despite its relatedness to S. cerevisiae that is employed widely in biotechnology, food and biofuel industries, the alternative applications of S. boulardii are not well studied. Using a biorefinery approach, we compared the bioethanol and biomass yields attainable from agriculturally-sourced grass juice using probiotic S. boulardii (strain MYA-769) and a commercial S. cerevisiae brewing strain (Turbo yeast). Maximum product yields for MYA-769 (39.18 [±2.42] mg ethanol mL(-1) and 4.96 [±0.15] g dry weight L(-1)) compared closely to those of Turbo (37.43 [±1.99] mg mL(-1) and 4.78 [±0.10] g L(-1), respectively). Co-production, marketing and/or on-site utilisation of probiotic yeast biomass as a direct-fed microbial to improve livestock health represents a novel and viable prospect for rural biorefineries. Given emergent evidence to suggest that dietary yeast supplementations might also mitigate ruminant enteric methane emissions, the administration of probiotic yeast biomass could also offer an economically feasible way of reducing atmospheric CH4.

Changes in methane emission, rumen fermentation, and methanogenic community in response to silage and dry cornstalk diets.

PubMed

Chong, Liu; Zhuping, Zhu; Tongjun, Guo; Yongming, Luo; Hongmin, Dong

2014-06-01

This study aimed to investigate the effect of silage or dry cornstalk diets on methane emission, rumen fermentation, and methanogenic community, and reveal whether the change of methanogenic compositions was related to the methane production. A total of 39 sheep were divided into four groups, fed diets of different concentrate level based on silage or dry cornstalk roughage for 40 days. It was found that, at 20% concentrate level, the sheep fed silage could suppress methanogenesis significantly in contrast with the silage diet (p < 0.05). The ruminal acetate:propionate ratio was 3.17 in the silage-fed sheep significantly lower than 3.78 in the dry cornstalk-fed sheep (p < 0.05), reflecting the effect of fermentation on methane output was related to roughage types. Furthermore, the methanogens was found to be significantly lower abundance (p < 0.05), and showed a different pattern using multivariate statistical analysis in silage-fed sheep. Compared with dry cornstalk diet, silage diet of 20% concentrate reduced methane production, decreased methanogenic abundance, and induced change of Methanobrevibacter composition at strain levels. This study showed variation of methanogenic compositions at strain level and its probable relationship with methane production, and provided microbial information to explain the low methane output when the animals were fed silage. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of apples and specific apple components on the cecal environment of conventional rats: role of apple pectin.

PubMed

Licht, Tine R; Hansen, Max; Bergström, Anders; Poulsen, Morten; Krath, Britta N; Markowski, Jaroslaw; Dragsted, Lars O; Wilcks, Andrea

2010-01-20

Our study was part of the large European project ISAFRUIT aiming to reveal the biological explanations for the epidemiologically well-established health effects of fruits. The objective was to identify effects of apple and apple product consumption on the composition of the cecal microbial community in rats, as well as on a number of cecal parameters, which may be influenced by a changed microbiota. Principal Component Analysis (PCA) of cecal microbiota profiles obtained by PCR-DGGE targeting bacterial 16S rRNA genes showed an effect of whole apples in a long-term feeding study (14 weeks), while no effects of apple juice, purée or pomace on microbial composition in cecum were observed. Administration of either 0.33 or 3.3% apple pectin in the diet resulted in considerable changes in the DGGE profiles.A 2-fold increase in the activity of beta-glucuronidase was observed in animals fed with pectin (7% in the diet) for four weeks, as compared to control animals (P < 0.01). Additionally, the level of butyrate measured in these pectin-fed animal was more than double of the corresponding level in control animals (P < 0.01). Sequencing revealed that DGGE bands, which were suppressed in pectin-fed rats, represented Gram-negative anaerobic rods belonging to the phylum Bacteroidetes, whereas bands that became more prominent represented mainly Gram-positive anaerobic rods belonging to the phylum Firmicutes, and specific species belonging to the Clostridium Cluster XIVa.Quantitative real-time PCR confirmed a lower amount of given Bacteroidetes species in the pectin-fed rats as well as in the apple-fed rats in the four-week study (P < 0.05). Additionally, a more than four-fold increase in the amount of Clostridium coccoides (belonging to Cluster XIVa), as well as of genes encoding butyryl-coenzyme A CoA transferase, which is involved in butyrate production, was detected by quantitative PCR in fecal samples from the pectin-fed animals. Our findings show that consumption of apple pectin (7% in the diet) increases the population of butyrate- and beta-glucuronidase producing Clostridiales, and decreases the population of specific species within the Bacteroidetes group in the rat gut. Similar changes were not caused by consumption of whole apples, apple juice, purée or pomace.

Intake, digestibility, and nitrogen retention by sheep supplemented with warm-season legume haylages or soybean meal.

PubMed

Foster, J L; Adesogan, A T; Carter, J N; Blount, A R; Myer, R O; Phatak, S C

2009-09-01

The high cost of commercial supplements necessitates evaluation of alternatives for ruminant livestock fed poor quality warm-season grasses. This study determined how supplementing bahiagrass haylage (Paspalum notatum Flügge cv. Tifton 9) with soybean [Glycine max (L.) Merr.] meal or warm-season legume haylages affected the performance of lambs. Forty-two Dorper x Katadhin lambs (27.5 +/- 5 kg) were fed for ad libitum intake of bahiagrass haylage (67.8% NDF, 9.6% CP) alone (control) or supplemented with soybean meal (18.8% NDF, 51.4% CP) or haylages of annual peanut [Arachis hypogaea (L.) cv. Florida MDR98; 39.6% NDF, 18.7% CP], cowpea [Vigna unguiculata (L.) Walp. cv. Iron clay; 44.1% NDF, 16.0% CP], perennial peanut (Arachis glabrata Benth. cv. Florigraze; 40.0% NDF, 15.8% CP), or pigeonpea [Cajanus cajan (L.) Millsp. cv. GA-2; 65.0% NDF, 13.7% CP]. Haylages were harvested at the optimal maturity for maximizing yield and nutritive value, wilted to 45% DM, baled, wrapped in polyethylene plastic, and ensiled for 180 d. Legumes were fed at 50% of the dietary DM, and soybean meal was fed at 8% of the dietary DM to match the average CP concentration (12.8%) of legume haylage-supplemented diets. Lambs were fed each diet for a 14-d adaptation period and a 7-d data collection period. Each diet was fed to 7 lambs in period 1 and 4 lambs in period 2. Pigeonpea haylage supplementation decreased (P < 0.01) DM and OM intake and digestibility vs. controls. Other legume haylages increased (P < 0.05) DM and OM intake vs. controls; however, only soybean meal supplementation increased (P = 0.01) DM digestibility. All supplements decreased (P = 0.05) NDF digestibility. Except for pigeonpea haylage, all supplements increased (P < 0.01) N intake, digestibility, and retention, and the responses were greatest (P = 0.04) with soybean meal supplementation. Microbial N synthesis was reduced (P = 0.02) by pigeonpea haylage supplementation, but unaffected (P = 0.05) by other supplements. Efficiency of microbial protein synthesis was unaffected (P = 0.05) by diet. Ruminal ammonia concentration was increased (P = 0.01) by all supplements, but only soybean meal and annual peanut haylage increased (P < 0.03) plasma urea-N concentrations. Perennial peanut, annual peanut, and cowpea haylages are promising protein supplements for growing lambs.

Effects of feeding crude glycerin on performance and ruminal kinetics of lactating Holstein cows fed corn silage- or cottonseed hull-based, low-fiber diets.

PubMed

Shin, J H; Wang, D; Kim, S C; Adesogan, A T; Staples, C R

2012-07-01

The objective was to determine whether crude glycerin could partially replace concentrate ingredients in corn silage- or cottonseed hull-based diets formulated to support minimal milk fat production without reducing milk production. Multiparous, lactating Holstein cows (n=24; 116 ± 13d in milk) were assigned to dietary treatments arranged in a 2 × 3 factorial design; namely, 2 dietary roughage sources (cottonseed hulls or corn silage) and 3 dietary concentrations of glycerin [0, 5, or 10% on a dry matter (DM) basis]. Four different cows received each dietary treatment in each of 3 periods such that each diet was evaluated using 12 cows. Crude glycerin, produced using soybean oil, contained 12% water, 5% oil, 6.8% sodium chloride, and 0.4% methanol. Glycerin partially replaced ground corn, corn gluten feed, and citrus pulp. Diets of minimum fiber concentrations were fed to lactating dairy cows and resulted in low concentrations of milk fat (averaging 3.12% for cows fed diets without glycerin). The effects of glycerin on cow performance and ruminal measurements were the same for both dietary roughage sources with the exception of feed efficiency. Replacing concentrate with crude glycerin at 5% of dietary DM increased DM intake without increasing milk yield. Concentration and yield of milk fat were reduced when glycerin was fed at 10% of dietary DM. This was accompanied by a 30% reduction in apparent total-tract digestion of dietary neutral detergent fiber. Crude glycerin affected the microbial population in the rumen as evidenced by increased molar proportions of propionic, butyric, and valeric acids and decreased molar proportions of acetic acid. Efficiency of N utilization was improved as evidenced by lower concentrations of blood urea nitrogen and ruminal ammonia-N. Cows fed cottonseed hull-based diets consumed 5.3 kg/d more DM but produced only 1.7 kg/d more milk, resulting in reduced efficiency. Increased production of ruminal microbial protein, molar proportion of propionic acid, and passage of ruminal fluid resulted from feeding the cottonseed hull- versus corn silage-based diets, although apparent digestibilities of DM and neutral detergent fiber were reduced. Replacing 5 and 10% of concentrate ingredients with crude glycerin improved efficiency of 4% fat-corrected milk production when corn silage-based diets were fed but decreased it when cottonseed hull-based diets were fed. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Recipient-Biased Competition for an Intracellularly Generated Cross-Fed Nutrient Is Required for Coexistence of Microbial Mutualists

DOE PAGES

McCully, Alexandra L.; LaSarre, Breah; McKinlay, James B.; ...

2017-11-28

ABSTRACT Many mutualistic microbial relationships are based on nutrient cross-feeding. Traditionally, cross-feeding is viewed as being unidirectional, from the producer to the recipient. This is likely true when a producer’s waste, such as a fermentation product, has value only for a recipient. However, in some cases the cross-fed nutrient holds value for both the producer and the recipient. In such cases, there is potential for nutrient reacquisition by producer cells in a population, leading to competition against recipients. Here, we investigated the consequences of interpartner competition for cross-fed nutrients on mutualism dynamics by using an anaerobic coculture pairing fermentative Escherichiamore » coli and phototrophic Rhodopseudomonas palustris . In this coculture, E. coli excretes waste organic acids that provide a carbon source for R. palustris . In return, R. palustris cross-feeds E. coli ammonium (NH 4 + ), a compound that both species value. To explore the potential for interpartner competition, we first used a kinetic model to simulate cocultures with varied affinities for NH 4 + in each species. The model predicted that interpartner competition for NH 4 + could profoundly impact population dynamics. We then experimentally tested the predictions by culturing mutants lacking NH 4 + transporters in both NH 4 + competition assays and mutualistic cocultures. Both theoretical and experimental results indicated that the recipient must have a competitive advantage in acquiring cross-fed NH 4 + to sustain the mutualism. This recipient-biased competitive advantage is predicted to be crucial, particularly when the communally valuable nutrient is generated intracellularly. Thus, the very metabolites that form the basis for mutualistic cross-feeding can also be subject to competition between mutualistic partners. IMPORTANCE Mutualistic relationships, particularly those based on nutrient cross-feeding, promote stability of diverse ecosystems and drive global biogeochemical cycles. Cross-fed nutrients within these systems can be either waste products valued by only one partner or nutrients valued by both partners. Here, we explored how interpartner competition for a communally valuable cross-fed nutrient impacts mutualism dynamics. We discovered that mutualism stability necessitates that the recipient have a competitive advantage against the producer in obtaining the cross-fed nutrient, provided that the nutrient is generated intracellularly. We propose that the requirement for recipient-biased competition is a general rule for mutualistic coexistence based on the transfer of intracellularly generated, communally valuable resources.« less

Recipient-Biased Competition for an Intracellularly Generated Cross-Fed Nutrient Is Required for Coexistence of Microbial Mutualists

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCully, Alexandra L.; LaSarre, Breah; McKinlay, James B.

ABSTRACT Many mutualistic microbial relationships are based on nutrient cross-feeding. Traditionally, cross-feeding is viewed as being unidirectional, from the producer to the recipient. This is likely true when a producer’s waste, such as a fermentation product, has value only for a recipient. However, in some cases the cross-fed nutrient holds value for both the producer and the recipient. In such cases, there is potential for nutrient reacquisition by producer cells in a population, leading to competition against recipients. Here, we investigated the consequences of interpartner competition for cross-fed nutrients on mutualism dynamics by using an anaerobic coculture pairing fermentative Escherichiamore » coli and phototrophic Rhodopseudomonas palustris . In this coculture, E. coli excretes waste organic acids that provide a carbon source for R. palustris . In return, R. palustris cross-feeds E. coli ammonium (NH 4 + ), a compound that both species value. To explore the potential for interpartner competition, we first used a kinetic model to simulate cocultures with varied affinities for NH 4 + in each species. The model predicted that interpartner competition for NH 4 + could profoundly impact population dynamics. We then experimentally tested the predictions by culturing mutants lacking NH 4 + transporters in both NH 4 + competition assays and mutualistic cocultures. Both theoretical and experimental results indicated that the recipient must have a competitive advantage in acquiring cross-fed NH 4 + to sustain the mutualism. This recipient-biased competitive advantage is predicted to be crucial, particularly when the communally valuable nutrient is generated intracellularly. Thus, the very metabolites that form the basis for mutualistic cross-feeding can also be subject to competition between mutualistic partners. IMPORTANCE Mutualistic relationships, particularly those based on nutrient cross-feeding, promote stability of diverse ecosystems and drive global biogeochemical cycles. Cross-fed nutrients within these systems can be either waste products valued by only one partner or nutrients valued by both partners. Here, we explored how interpartner competition for a communally valuable cross-fed nutrient impacts mutualism dynamics. We discovered that mutualism stability necessitates that the recipient have a competitive advantage against the producer in obtaining the cross-fed nutrient, provided that the nutrient is generated intracellularly. We propose that the requirement for recipient-biased competition is a general rule for mutualistic coexistence based on the transfer of intracellularly generated, communally valuable resources.« less

Recipient-Biased Competition for an Intracellularly Generated Cross-Fed Nutrient Is Required for Coexistence of Microbial Mutualists.

PubMed

McCully, Alexandra L; LaSarre, Breah; McKinlay, James B

2017-11-28

Many mutualistic microbial relationships are based on nutrient cross-feeding. Traditionally, cross-feeding is viewed as being unidirectional, from the producer to the recipient. This is likely true when a producer's waste, such as a fermentation product, has value only for a recipient. However, in some cases the cross-fed nutrient holds value for both the producer and the recipient. In such cases, there is potential for nutrient reacquisition by producer cells in a population, leading to competition against recipients. Here, we investigated the consequences of interpartner competition for cross-fed nutrients on mutualism dynamics by using an anaerobic coculture pairing fermentative Escherichia coli and phototrophic Rhodopseudomonas palustris In this coculture, E. coli excretes waste organic acids that provide a carbon source for R. palustris In return, R. palustris cross-feeds E. coli ammonium (NH 4 + ), a compound that both species value. To explore the potential for interpartner competition, we first used a kinetic model to simulate cocultures with varied affinities for NH 4 + in each species. The model predicted that interpartner competition for NH 4 + could profoundly impact population dynamics. We then experimentally tested the predictions by culturing mutants lacking NH 4 + transporters in both NH 4 + competition assays and mutualistic cocultures. Both theoretical and experimental results indicated that the recipient must have a competitive advantage in acquiring cross-fed NH 4 + to sustain the mutualism. This recipient-biased competitive advantage is predicted to be crucial, particularly when the communally valuable nutrient is generated intracellularly. Thus, the very metabolites that form the basis for mutualistic cross-feeding can also be subject to competition between mutualistic partners. IMPORTANCE Mutualistic relationships, particularly those based on nutrient cross-feeding, promote stability of diverse ecosystems and drive global biogeochemical cycles. Cross-fed nutrients within these systems can be either waste products valued by only one partner or nutrients valued by both partners. Here, we explored how interpartner competition for a communally valuable cross-fed nutrient impacts mutualism dynamics. We discovered that mutualism stability necessitates that the recipient have a competitive advantage against the producer in obtaining the cross-fed nutrient, provided that the nutrient is generated intracellularly. We propose that the requirement for recipient-biased competition is a general rule for mutualistic coexistence based on the transfer of intracellularly generated, communally valuable resources. Copyright © 2017 McCully et al.

Comparison of analgesic effect of direct breastfeeding, oral 25% dextrose solution and placebo during 1st DPT vaccination in healthy term infants: a randomized, placebo controlled trial.

PubMed

Goswami, Gaurav; Upadhyay, Amit; Gupta, Navratan Kumar; Chaudhry, Rajesh; Chawla, Deepak; Sreenivas, V

2013-07-01

To compare analgesic effect of direct breast feeding, 25% dextrose solution and placebo as we give 1st intramuscular whole cell DPT injection to 6week - 3month old infants. Randomized, placebo controlled trial. Immunization clinic of Department of Pediatrics, LLRM Medical College. Infants coming for their 1st DPT vaccination were randomized in to three groups of 40 each. The primary outcome variable was the duration of cry after vaccination. Secondary outcome variables were Modified Facial Coding Score (MFCS) and latency of onset of cry. 120 babies were equally enrolled in breast feed group, 25% dextrose fed group and distilled water fed group. Median (interquartile range) of duration of cry was significantly lower in breast fed (33.5 (17-54) seconds) and 25% dextrose fed babies (47.5 (31-67.5) seconds) as compared to babies given distilled water (80.5 (33.5-119.5) seconds) (P<0.001). MFCS at 1 min and 3 min was significantly lower in direct breast fed and dextrose fed babies. Direct breastfeeding and 25% dextrose act as analgesic in young infants undergoing DPT vaccination in young infants less than 3 month of age.

Microbial diversity in The Cedars, an ultrabasic, ultrareducing, and low salinity serpentinizing ecosystem.

PubMed

Suzuki, Shino; Ishii, Shun'ichi; Wu, Angela; Cheung, Andrea; Tenney, Aaron; Wanger, Greg; Kuenen, J Gijs; Nealson, Kenneth H

2013-09-17

The Cedars, in coastal northern California, is an active site of peridotite serpentinization. The spring waters that emerge from this system feature very high pH, low redox potential, and low ionic concentrations, making it an exceptionally challenging environment for life. We report a multiyear, culture-independent geomicrobiological study of three springs at The Cedars that differ with respect to the nature of the groundwater feeding them. Within each spring, both geochemical properties and microbial diversity in all three domains of life remained stable over a 3-y period, with multiple samples each year. Between the three springs, however, the microbial communities showed considerable differences that were strongly correlated with the source of the serpentinizing groundwater. In the spring fed solely by deep groundwater, phylum Chloroflexi, class Clostridia, and candidate division OD1 were the major taxa with one phylotype in Euryarchaeota. Less-abundant phylotypes include several minor members from other candidate divisions and one phylotype that was an outlier of candidate division OP3. In the springs fed by the mixture of deep and shallow groundwater, organisms close to the Hydrogenophaga within Betaproteobacteria dominated and coexisted with the deep groundwater community members. The shallow groundwater community thus appears to be similar to those described in other terrestrial serpentinizing sites, whereas the deep community is distinctly different from any other previously described terrestrial serpentinizing community. These unique communities have the potential to yield important insights into the development and survival of life in these early-earth analog environments.

Microbial diversity in The Cedars, an ultrabasic, ultrareducing, and low salinity serpentinizing ecosystem

PubMed Central

Suzuki, Shino; Ishii, Shun’ichi; Wu, Angela; Cheung, Andrea; Tenney, Aaron; Wanger, Greg; Kuenen, J. Gijs; Nealson, Kenneth H.

2013-01-01

The Cedars, in coastal northern California, is an active site of peridotite serpentinization. The spring waters that emerge from this system feature very high pH, low redox potential, and low ionic concentrations, making it an exceptionally challenging environment for life. We report a multiyear, culture-independent geomicrobiological study of three springs at The Cedars that differ with respect to the nature of the groundwater feeding them. Within each spring, both geochemical properties and microbial diversity in all three domains of life remained stable over a 3-y period, with multiple samples each year. Between the three springs, however, the microbial communities showed considerable differences that were strongly correlated with the source of the serpentinizing groundwater. In the spring fed solely by deep groundwater, phylum Chloroflexi, class Clostridia, and candidate division OD1 were the major taxa with one phylotype in Euryarchaeota. Less-abundant phylotypes include several minor members from other candidate divisions and one phylotype that was an outlier of candidate division OP3. In the springs fed by the mixture of deep and shallow groundwater, organisms close to the Hydrogenophaga within Betaproteobacteria dominated and coexisted with the deep groundwater community members. The shallow groundwater community thus appears to be similar to those described in other terrestrial serpentinizing sites, whereas the deep community is distinctly different from any other previously described terrestrial serpentinizing community. These unique communities have the potential to yield important insights into the development and survival of life in these early-earth analog environments. PMID:24003156

Impact of genistein on the gut microbiome of humanized mice and its role in breast tumor inhibition.

PubMed

Paul, Bidisha; Royston, Kendra J; Li, Yuanyuan; Stoll, Matthew L; Skibola, Christine F; Wilson, Landon S; Barnes, Stephen; Morrow, Casey D; Tollefsbol, Trygve O

2017-01-01

Since dietary polyphenols can have beneficial effects in prevention and treatment of cancer, we tested the hypothesis that breast cancer patients' intestinal microbiota is modulated by genistein (GE), an isoflavone found in soy, and that microbial alterations may offset the side effects brought about by chemotherapy. We demonstrated successful humanization of germ-free mice by transplanting fecal samples from breast cancer patients before and after chemotherapy. Mice were then grouped based on chemotherapy status and GE or control diet. We did not find any significant differences between pre-chemotherapy and post-chemotherapy bacterial composition and abundances. Germ-free mice on a GE diet showed differences in microbial composition as compared to mice on control diet. Four weeks after introduction of the customized GE diet, there was distinct clustering of GE-fed mice as compared to the control-fed group. In the gut microbiome of GE-treated humanized mice, there was an increase in abundance of genera Lactococcus and Eubacterium. Phylum Verrucomicrobia showed statistically significant (p = 0.02) differences in abundances between the GE-fed and control-fed groups. There was an increase in bacteria belonging to family Lachnospiraceae and Ruminococcaceae in GE-fed mice. Marked changes were observed in GE catabolism in mice humanized with fecal material from two of three patients' post-chemotherapy with complete disappearance of 4-ethylphenol and 2-(4-hydroxyphenol) propionic acid conjugates. The post-tumor samples did not show any distinct clustering of the gut microbiota between the two diet groups. There was an increase in latency of about 25% for tumor growth of the humanized mice that were on a GE diet as compared to humanized mice on a control diet. The average tumor size for the GE group was significantly decreased compared to the non-GE group. Collectively, our results suggest that the intestinal microbiota becomes altered with a GE diet before induction of tumor. Our findings indicate that GE modulates the microbiome in humanized mice that may contribute to its effects on increasing the latency of breast tumor and reducing tumor growth.

Precision-feeding dairy heifers a high rumen-degradable protein diet with different proportions of dietary fiber and forage-to-concentrate ratios.

PubMed

Lascano, G J; Koch, L E; Heinrichs, A J

2016-09-01

The objective of this experiment was to determine the effects of feeding a high-rumen-degradable protein (RDP) diet when dietary fiber content is manipulated within differing forage-to-concentrate ratio (F:C) on nutrient utilization of precision-fed dairy heifers. Six cannulated Holstein heifers (486.98±15.07kg of body weight) were randomly assigned to 2 F:C, low- (45% forage; LF) and high-forage (90% forage; HF) diets and to a fiber proportion sequence [33% grass hay and wheat straw (HS), 67% corn silage (CS; low fiber); 50% HS, 50% CS (medium fiber); and 67% HS, 33% CS (high fiber)] within forage proportion administered according to a split-plot, 3×3 Latin square design (16-d periods). Heifers fed LF had greater apparent total-tract organic matter digestibility coefficients (dC), neutral detergent fiber, and cellulose than those fed LC diets. Substituting CS with HS resulted in a linear reduction in dry matter, organic matter, and cellulose dC. Nitrogen dC was not different between F:C or with increasing proportions of HS in diets, but N retention tended to decrease linearly as HS was increased in the diets. Predicted microbial protein flow to the duodenum decreased linearly with HS addition and protozoa numbers HS interacted linearly, exhibiting a decrease as HS increased for LF, whereas no effects were observed for HF. Blood urea N increased linearly as HS was incorporated. The LF-fed heifers had a greater ruminal volatile fatty acids concentration. We noted a tendency for a greater dry matter, and a significantly higher liquid fraction turnover rate for HF diets. There was a linear numerical increase in the liquid and solid fraction turnover rate as fiber was added to the diets. Rumen fermentation parameters and fractional passages (solid and liquid) rates support the reduction in dC, N retention, and microbial protein synthesis observed as more dietary fiber is added to the rations of dairy heifers precision-fed a constant proportion of rumen-degradable protein. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Impact of genistein on the gut microbiome of humanized mice and its role in breast tumor inhibition

PubMed Central

Paul, Bidisha; Royston, Kendra J.; Li, Yuanyuan; Stoll, Matthew L.; Skibola, Christine F.; Wilson, Landon S.; Barnes, Stephen; Morrow, Casey D.

2017-01-01

Since dietary polyphenols can have beneficial effects in prevention and treatment of cancer, we tested the hypothesis that breast cancer patients’ intestinal microbiota is modulated by genistein (GE), an isoflavone found in soy, and that microbial alterations may offset the side effects brought about by chemotherapy. We demonstrated successful humanization of germ-free mice by transplanting fecal samples from breast cancer patients before and after chemotherapy. Mice were then grouped based on chemotherapy status and GE or control diet. We did not find any significant differences between pre-chemotherapy and post-chemotherapy bacterial composition and abundances. Germ-free mice on a GE diet showed differences in microbial composition as compared to mice on control diet. Four weeks after introduction of the customized GE diet, there was distinct clustering of GE-fed mice as compared to the control-fed group. In the gut microbiome of GE-treated humanized mice, there was an increase in abundance of genera Lactococcus and Eubacterium. Phylum Verrucomicrobia showed statistically significant (p = 0.02) differences in abundances between the GE-fed and control-fed groups. There was an increase in bacteria belonging to family Lachnospiraceae and Ruminococcaceae in GE-fed mice. Marked changes were observed in GE catabolism in mice humanized with fecal material from two of three patients’ post-chemotherapy with complete disappearance of 4-ethylphenol and 2-(4-hydroxyphenol) propionic acid conjugates. The post-tumor samples did not show any distinct clustering of the gut microbiota between the two diet groups. There was an increase in latency of about 25% for tumor growth of the humanized mice that were on a GE diet as compared to humanized mice on a control diet. The average tumor size for the GE group was significantly decreased compared to the non-GE group. Collectively, our results suggest that the intestinal microbiota becomes altered with a GE diet before induction of tumor. Our findings indicate that GE modulates the microbiome in humanized mice that may contribute to its effects on increasing the latency of breast tumor and reducing tumor growth. PMID:29267377

Variable efficacy of a vaccine and direct-fed microbial for controlling Escherichia coli O157:H7 in feces and on hides of feedlot cattle.

PubMed

Stanford, Kim; Hannon, Sherry; Booker, Calvin W; Jim, G Kee

2014-05-01

To evaluate the efficacy of a type-III secreted proteins vaccine and a Lactobacillus-acidophilus-based direct-fed microbial (DFM) for controlling Escherichia coli O157:H7, cattle (n=864) were allocated to the following groups: DFM, finishing diets containing 10(9) colony-forming units (CFU)/animal/day L. acidophilus and Propionibacterium freudenreichii; VAC, finishing diets and 2 mL intramuscular injection of vaccine at allocation and 28 days later; or CON, finishing diets only. Cattle within replicates were stratified by initial levels of E. coli O157:H7 and randomized to experimental groups, with 30 pens allocated on June 15, 2011 (AS1), 18 pens allocated on June 28, 2011 (AS2), and 18 cattle per pen. Rectal fecal samples and perineal swabs were collected at 28-day intervals until shipment to slaughter (103-145 days on trial). Numbers of cattle with enumerable E. coli O157:H7 (≥1.6 CFU/g feces) were reduced in AS1 and AS2 by VAC (p=0.008), although interventions had no impact on numbers of E. coli O157:H7 shed. For AS1, VAC reduced prevalence of E. coli O157:H7 in feces (p=0.03) and perineal swabs (p=0.04) in the feeding period but not at shipment to slaughter. For AS2, prevalence of E. coli O157:H7 was not reduced in either feces or perineal swabs by VAC at any time. For AS1, DFM reduced prevalence of E. coli O157:H7 in perineal swabs (p=0.01) during the feeding period. For AS2, DFM increased E. coli O157:H7 detection in feces (p=0.03) and perineal swabs (p=0.01) at shipment to slaughter. Seventy-five percent of AS1 E. coli O157:H7 isolates had only stx1, while 87% of AS2 isolates had stx1 and stx2 genes. Of the two interventions, VAC shows the most potential for pre-harvest control of E. coli O157:H7, but due to variable efficacy of both DFM and VAC, additional product development is necessary to ensure more consistent pre-harvest control of E. coli O157:H7.

Molecular detection and quantification of viable probiotic strains in animal feedstuffs using the commercial direct fed microbial Lactobacillus animalis NP51 as a model.

PubMed

Ayala, D I; Chen, J C; Bugarel, M; Loneragan, G H; den Bakker, H C; Kottapalli, K R; Brashears, M M; Nightingale, K K

2018-04-17

Lactobacillus animalis NP51 is a direct-fed microbial strain (DFM) extensively used as a pre-harvest food safety mitigation in feedlot cattle due to its antagonistic effects against human foodborne pathogens such as Salmonella and Escherichia coli O157:H7. NP51 not only promotes overall gut health but interferes with the ability of these pathogens to colonize the gastrointestinal tract of cattle. As a result, NP51 reduces fecal shedding of Salmonella and E. coli O157:H7 in cattle presented for harvest and the load of these pathogens that enter the human food chain. Cattle are administered a high dose (1 × 10 9  CFU/head/day) of NP51 to reduce fecal shedding of foodborne pathogens. Ensiled animal feedstuffs naturally contain a high load of lactic acid bacteria (LAB) and it is not possible to detect and quantify the level of a specific LAB strain (e.g., NP51) in this matrix using traditional microbiological culture. The purpose of this study was to develop a molecular method to detect and quantify viable populations of a specific LAB strain (e.g., NP51) in cattle feedstuffs. The NP51 whole genome sequence was aligned with closely related LAB clustering within the same well-supported clade in a LAB phylogeny derived from 30 conserved amino acid encoding sequence to identify orthologs. A sequence encoding recombinational DNA repair protein RecT was found to be unique to NP51 and used to design primers and a probe for molecular detection and quantification of NP51. The primers and probe were confirmed to be specific to NP51 in vitro. Total RNA was extracted from silage samples, including samples naturally inoculated in the field and control samples that were artificially spiked with a range of NP51 concentrations in the laboratory. Reverse-transcriptase quantitative real-time (RT-qRTi) PCR was used to quantify cDNA copies in samples and cycle threshold (Ct) values were compared to a standard curve to estimate NP51 concentrations. Our results indicate this novel molecular method is suitable to confirm the presence and estimate the concentration of a specific LAB strain in animal feedstuffs containing high background levels of LAB. Copyright © 2018. Published by Elsevier B.V.

Physical Factors Correlate to Microbial Community Structure and Nitrogen Cycling Gene Abundance in a Nitrate Fed Eutrophic Lagoon.

PubMed

Highton, Matthew P; Roosa, Stéphanie; Crawshaw, Josie; Schallenberg, Marc; Morales, Sergio E

2016-01-01

Nitrogenous run-off from farmed pastures contributes to the eutrophication of Lake Ellesmere, a large shallow lagoon/lake on the east coast of New Zealand. Tributaries periodically deliver high loads of nitrate to the lake which likely affect microbial communities therein. We hypothesized that a nutrient gradient would form from the potential sources (tributaries) creating a disturbance resulting in changes in microbial community structure. To test this we first determined the existence of such a gradient but found only a weak nitrogen (TN) and phosphorous gradient (DRP). Changes in microbial communities were determined by measuring functional potential (quantification of nitrogen cycling genes via nifH , nirS , nosZI , and nosZII using qPCR), potential activity (via denitrification enzyme activity), as well as using changes in total community (via 16S rRNA gene amplicon sequencing). Our results demonstrated that changes in microbial communities at a phylogenetic (relative abundance) and functional level (proportion of the microbial community carrying nifH and nosZI genes) were most strongly associated with physical gradients (e.g., lake depth, sediment grain size, sediment porosity) and not nutrient concentrations. Low nitrate influx at the time of sampling is proposed as a factor contributing to the observed patterns.

Population dynamics of electrogenic microbial communities in microbial fuel cells started with three different inoculum sources.

PubMed

Ishii, Shun'ichi; Suzuki, Shino; Yamanaka, Yuko; Wu, Angela; Nealson, Kenneth H; Bretschger, Orianna

2017-10-01

Microbial fuel cells (MFCs) are one of the bioelectrochemical systems that exploit microorganisms as biocatalysts to degrade organic matters and recover energy as electric power. Here, we explored how the established electrogenic microbial communities were influenced by three different inoculum sources; anaerobic sludge of the wastewater plant, rice paddy field soil, and coastal lagoon sediment. We periodically characterized both electricity generation with sucrose consumption and 16S rRNA-basis microbial community composition. The electrochemical features of MFCs were slightly different among three inocula, and the lagoon sediment-inoculated MFC showed the highest performance in terms of the treatment time. Meanwhile, although the inoculated microbial communities were highly diverse and quite different, only twelve genera affiliated with δ-Proteobacteria, γ-Proteobacteria, Bacilli, Clostridia/Negativicutes or Bacteroidetes were abundantly enriched in all MFC anode communities. Within them, several fermentative genera were clearly different due to the inocula, while the inocula-specific phylotypes were identified in an electrogenic genus Geobacter. The relative abundances of phylotypes closely-related to Geobacter metallireducens were increased in later stages of all the sucrose-fed MFCs. These results indicate that key microbial members for the functional electrogenic community widely exist in natural ecosystems, but the community members presenting in inoculum sources affected the MFC performances. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of NovaSil dietary supplementation on the growth and health performance of Nile tilapia (Oreochromis niloticus) fed aflatoxin-B1 contaminated feed

USDA-ARS?s Scientific Manuscript database

The objective of this study was to evaluate the ability of NovaSil (NS) clay to sorb and mitigate the toxic effects of aflatoxin B1 (AFB1) in Nile tilapia (Oreochromis niloticus). Growth performance, specific innate immunological function, intestinal microbial community, and histology were evaluate...

Evaluation of the ruminal bacterial diversity of cattle fed diets containing citrus pulp pellets (CPP) using bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP)

USDA-ARS?s Scientific Manuscript database

The rumen microbial ecosystem has been extensively studied, but remains a mystery from a quantitative perspective. Dietary components and changes cause shifts in the ruminal microflora that can affect animal health and productivity, but the majority of these changes remain unknown. The objective of ...

Effects of applied potential on phosphine formation in synthetic wastewater treatment by Microbial Electrolysis Cell (MEC).

PubMed

Liu, Wei; Niu, Xiaojun; Chen, Weiyi; An, Shaorong; Sheng, Hong

2017-04-01

Phosphine (PH 3 ) emission from conventional biological wastewater treatment is very inefficient (ng-μg m -3 ). In this work, we investigated the feasibility of promoting PH 3 formation from inorganic phosphorus (IP) or organic phosphorus (OP) containing synthetic wastewater treatment by Microbial Electrolysis Cell (MEC) for the first time. Positive effect of applied potential on PH 3 production was observed after methanogens was inhibited. The highest production of PH 3 (1103.10 ± 72.02 ng m -3 ) was obtained in IP-fed MEC operated at -0.6 V, which was about 5-fold and 2-fold compared to that in open circuit experiment and OP-fed MEC, respectively. Meanwhile, PH 3 formation corresponded positively with current density and alkaline phosphatase activity. This result showed that suitable potential could enhance the activity of relevant enzymes and boost the biosynthesis of PH 3 . Bacterial communities analysis based on high-throughput sequencing revealed that applied potential was conductive to the enrichment of phosphate-reducing organisms in contrast to the control test. These results provide a new idea for resource utilization of phosphorus in wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immobilization of Cr(VI) and Its Reduction to Cr(III) Phosphate by Granular Biofilms Comprising a Mixture of Microbes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nancharaiah, Y.V.; Francis, A.; Dodge, C.

2010-04-01

We assessed the potential of mixed microbial consortia, in the form of granular biofilms, to reduce chromate and remove it from synthetic minimal medium. In batch experiments, acetate-fed granular biofilms incubated aerobically reduced 0.2 mM Cr(VI) from a minimal medium at 0.15 mM day-1 g-1, with reduction of 0.17 mM day-1 g-1 under anaerobic conditions. There was negligible removal of Cr(VI) (i) without granular biofilms, (ii) with lyophilized granular biofilms, and (iii) with granules in the absence of an electron donor. Analyses by X-ray absorption near edge spectroscopy (XANES) of the granular biofilms revealed the conversion of soluble Cr(VI) tomore » Cr(III). Extended X-ray absorption fine-structure (EXAFS) analysis of the Cr-laden granular biofilms demonstrated similarity to Cr(III) phosphate, indicating that Cr(III) was immobilized with phosphate on the biomass subsequent to microbial reduction. The sustained reduction of Cr(VI) by granular biofilms was confirmed in fed-batch experiments. Our study demonstrates the promise of granular-biofilm-based systems in treating Cr(VI)-containing effluents and wastewater.« less

Hybrid modeling of microbial exopolysaccharide (EPS) production: The case of Enterobacter A47.

PubMed

Marques, Rodolfo; von Stosch, Moritz; Portela, Rui M C; Torres, Cristiana A V; Antunes, Sílvia; Freitas, Filomena; Reis, Maria A M; Oliveira, Rui

2017-03-20

Enterobacter A47 is a bacterium that produces high amounts of a fucose-rich exopolysaccharide (EPS) from glycerol residue of the biodiesel industry. The fed-batch process is characterized by complex non-linear dynamics with highly viscous pseudo-plastic rheology due to the accumulation of EPS in the culture medium. In this paper, we study hybrid modeling as a methodology to increase the predictive power of models for EPS production optimization. We compare six hybrid structures that explore different levels of knowledge-based and machine-learning model components. Knowledge-based components consist of macroscopic material balances, Monod type kinetics, cardinal temperature and pH (CTP) dependency and power-law viscosity models. Unknown dependencies are set to be identified by a feedforward artificial neural network (ANN). A semiparametric identification schema is applied resorting to a data set of 13 independent fed-batch experiments. A parsimonious hybrid model was identified that describes the dynamics of the 13 experiments with the same parameterization. The final model is specific to Enterobacter A47 but can be easily extended to other microbial EPS processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Dual utilization of NADPH and NADH cofactors enhances xylitol production in engineered Saccharomyces cerevisiae.

PubMed

Jo, Jung-Hyun; Oh, Sun-Young; Lee, Hyeun-Soo; Park, Yong-Cheol; Seo, Jin-Ho

2015-12-01

Xylitol, a natural sweetener, can be produced by hydrogenation of xylose in hemicelluloses. In microbial processes, utilization of only NADPH cofactor limited commercialization of xylitol biosynthesis. To overcome this drawback, Saccharomyces cerevisiae D452-2 was engineered to express two types of xylose reductase (XR) with either NADPH-dependence or NADH-preference. Engineered S. cerevisiae DWM expressing both the XRs exhibited higher xylitol productivity than the yeast strain expressing NADPH-dependent XR only (DWW) in both batch and glucose-limited fed-batch cultures. Furthermore, the coexpression of S. cerevisiae ZWF1 and ACS1 genes in the DWM strain increased intracellular concentrations of NADPH and NADH and improved maximum xylitol productivity by 17%, relative to that for the DWM strain. Finally, the optimized fed-batch fermentation of S. cerevisiae DWM-ZWF1-ACS1 resulted in 196.2 g/L xylitol concentration, 4.27 g/L h productivity and almost the theoretical yield. Expression of the two types of XR utilizing both NADPH and NADH is a promising strategy to meet the industrial demands for microbial xylitol production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization and optimization of cathodic conditions for H2O2 synthesis in microbial electrochemical cells.

PubMed

Sim, Junyoung; An, Junyeong; Elbeshbishy, Elsayed; Ryu, Hodon; Lee, Hyung-Sool

2015-11-01

Cathode potential and O2 supply methods were investigated to improve H2O2 synthesis in an electrochemical cell, and optimal cathode conditions were applied for microbial electrochemical cells (MECs). Using aqueous O2 for the cathode significantly improved current density, but H2O2 conversion efficiency was negligible at 0.3-12%. Current density decreased for passive O2 diffusion to the cathode, but H2O2 conversion efficiency increased by 65%. An MEC equipped with a gas diffusion cathode was operated with acetate medium and domestic wastewater, which presented relatively high H2O2 conversion efficiency from 36% to 47%, although cathode overpotential was fluctuated. Due to different current densities, the maximum H2O2 production rate was 141 mg H2O2/L-h in the MEC fed with acetate medium, but it became low at 6 mg H2O2/L-h in the MEC fed with the wastewater. Our study clearly indicates that improving anodic current density and mitigating membrane fouling would be key parameters for large-scale H2O2-MECs. Copyright © 2015 Elsevier Ltd. All rights reserved.

The role of early life nutrition in the establishment of gastrointestinal microbial composition and function

PubMed Central

Davis, Erin C.; Wang, Mei; Donovan, Sharon M.

2017-01-01

ABSTRACT The development of the human infant intestinal microbiota is a sequential process that begins in utero and continues during the first 2 to 3 years of life. Microbial composition and diversity are shaped by host genetics and multiple environmental factors, of which diet is a principal contributor. An understanding of this process is of clinical importance as the microbiota acquired in early life influence gastrointestinal, immune and neural development, and reduced microbial diversity or dysbiosis during infancy is associated with disorders in infancy and later childhood. The goal of this article was to review the published literature that used culture-independent methods to describe the development of the gastrointestinal microbiota in breast- and formula-fed human infants as well as the impact of prebiotic and probiotic addition to infant formula, and the addition of solid foods. PMID:28068209

Influence of nitrate, sulfate and operational parameters on the bioreduction of perchlorate using an up-flow packed bed reactor at high salinity.

PubMed

Chung, J; Shin, S; Oh, J

2010-05-01

In this study we have investigated whether electron acceptors, such as nitrate or sulphate ions, competitively inhibit the reduction of perchlorate in brine in continuous up-flow packed bed bioreactors. The effect of pH and hydraulic retention time (HRT) on the reduction of perchlorate at high salinity has also been examined. Reduction of perchlorate was found to be only moderately influenced by nitrate (under 163 mg N L-'), implying that there was no significant microbial competition for electron acceptors. As a result of microbial diversity, there were few differences between microbial communities fed with a variety of media, suggesting that most nitrate-reducing bacteria are able to reduce perchlorate at high salinity. Reduction of perchlorate was almost complete at relatively high sulfate levels (1000 mg L(-1)), neutral pH (6-8) and relatively long HRTs (> 10 h).

Diet and the intestinal microbiome: associations, functions, and implications for health and disease.

PubMed

Albenberg, Lindsey G; Wu, Gary D

2014-05-01

The mutual relationship between the intestinal microbiota and its mammalian host is influenced by diet. Consumption of various nutrients affects the structure of the microbial community and provides substrates for microbial metabolism. The microbiota can produce small molecules that are absorbed by the host and affect many important physiological processes. Age-dependent and societal differences in the intestinal microbiota could result from differences in diet. Examples include differences in the intestinal microbiota of breastfed vs formula-fed infants or differences in microbial richness in people who consume an agrarian plant-based vs a Western diet, which is high in meat and fat. We review how diet affects the structure and metabolome of the human intestinal microbiome and may contribute to health or the pathogenesis of disorders such as coronary vascular disease and inflammatory bowel disease. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

Influence of film mulching on soil microbial community in a rainfed region of northeastern China.

PubMed

Dong, Wenyi; Si, Pengfei; Liu, Enke; Yan, Changrong; Zhang, Zhe; Zhang, Yanqing

2017-08-16

Information about the effect of plastic film mulching (PFM) on the soil microbial communities of rainfed regions remains scarce. In the present study, Illumina Hiseq sequencer was employed to compare the soil bacterial and fungal communities under three treatments: no mulching (NM), spring mulching (SM) and autumn mulching (AM) in two layers (0-10 and, 10-20 cm). Our results demonstrated that the plastic film mulching (PFM) application had positive effects on soil physicochemical properties as compared to no-mulching (NM): higher soil temperature (ST), greater soil moisture content (SMC) and better soil nutrients. Moreover, mulching application (especially AM) caused a significant increase of bacterial and fungal richness and diversity and played important roles in shaping microbial community composition. These effects were mainly explained by the ST and SMC induced by the PFM application. The positive effects of AM and SM on species abundances were very similar, while the AM harbored relatively more beneficial microbial taxa than the SM, e.g., taxa related to higher degrading capacity and nutrient cycling. According to the overall effects of AM application on ST, SMC, soil nutrients and microbial diversity, AM is recommended during maize cultivation in rain-fed region of northeast China.

Pilot scale biodiesel production from microbial oil of Rhodosporidium toruloides DEBB 5533 using sugarcane juice: Performance in diesel engine and preliminary economic study.

PubMed

Soccol, Carlos Ricardo; Dalmas Neto, Carlos José; Soccol, Vanete Thomaz; Sydney, Eduardo Bittencourt; da Costa, Eduardo Scopel Ferreira; Medeiros, Adriane Bianchi Pedroni; Vandenberghe, Luciana Porto de Souza

2017-01-01

A successful pilot-scale process for biodiesel production from microbial oil (Biooil) produced by Rhodosporidium toruloides DEBB 5533 is presented. Using fed-batch strategy (1000L working volume), a lipid productivity of 0.44g/L.h was obtained using a low-cost medium composed by sugarcane juice and urea. The microbial oil was used for biodiesel production and its performance was evaluated in diesel engine tests, showing very good performance, especially for the blend B20 SCO, when operating at 2500rpm with lower pollutant emissions (CO 2 - 220% less; CO - 7-fold less; NO X 50% less and no detectable HC emissions (<0.11ppm)) when compared with the blends of standard biofuel from soybean oil. A preliminary analysis showed that microbial biodiesel is economically competitive (US$ 0.76/L) when compared to the vegetable biodiesel (US$ 0.81/L). Besides, the yield of biodiesel from microbial oil is higher (4172L/ha of cultivated sugarcane) that represents 6.3-fold the yield of standard biodiesel (661L/ha of cultivated soybean). Copyright © 2016 Elsevier Ltd. All rights reserved.

Detailed dimethylacetal and fatty acid composition of rumen content from lambs fed lucerne or concentrate supplemented with soybean oil.

PubMed

Alves, Susana P; Santos-Silva, José; Cabrita, Ana R J; Fonseca, António J M; Bessa, Rui J B

2013-01-01

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18:2n-6 and 18:3n-3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n-3.

Milk fatty acid composition, rumen microbial population, and animal performances in response to diets rich in linoleic acid supplemented with chestnut or quebracho tannins in dairy ewes.

PubMed

Buccioni, A; Pauselli, M; Viti, C; Minieri, S; Pallara, G; Roscini, V; Rapaccini, S; Marinucci, M Trabalza; Lupi, P; Conte, G; Mele, M

2015-02-01

The aim of the study was to evaluate milk fatty acid (FA) profile, animal performance, and rumen microbial population in response to diets containing soybean oil supplemented or not with chestnut and quebracho tannins in dairy ewes. Eighteen Comisana ewes at 122±6 d in milking were allotted into 3 experimental groups. Diets were characterized by chopped grass hay administered ad libitum and by 800 g/head and day of 3 experimental concentrates containing 84.5 g of soybean oil/kg of dry matter (DM) and 52.8 g/kg of DM of bentonite (control diet), chestnut tannin extract (CHT diet), or quebracho tannin extract (QUE diet). The trial lasted 4 wk. Milk yield was recorded daily, and milk composition and blood parameters were analyzed weekly. At the end of the experiment, samples of rumen fluid were collected to analyze pH, volatile fatty acid profile, and the relative proportions of Butyrivibrio fibrisolvens and Butyrivibrio proteoclasticus in the rumen microbial population. Hepatic functionality, milk yield, and gross composition were not affected by tannin extracts, whereas milk FA composition was characterized by significant changes in the concentration of linoleic acid (CHT +2.77% and QUE +9.23%), vaccenic acid (CHT +7.07% and QUE +13.88%), rumenic acid (CHT -1.88% and QUE +24.24%), stearic acid (CHT + 8.71% and QUE -11.45%), and saturated fatty acids (CHT -0.47% and QUE -3.38%). These differences were probably due to the ability of condensed versus hydrolyzable tannins to interfere with rumen microbial metabolism, as indirectly confirmed by changes in the relative proportions of B. fibrisolvens and B. proteoclasticus populations and by changes in the molar proportions of volatile fatty acids. The effect of the CHT diet on the milk FA profile and microbial species considered in this trial was intermediate between that of QUE and the control diet, suggesting a differential effect of condensed and hydrolyzable tannins on rumen microbes. Compared with control animals, the presence of B. fibrisolvens increased about 3 times in ewes fed CHT and about 5 times in animals fed QUE. In contrast, the abundance of B. proteoclasticus decreased about 5- and 15-fold in rumen liquor of ewes fed CHT and QUE diets, respectively. The use of soybean oil and a practical dose of QUE or CHT extract in the diet of dairy ewes can be an efficient strategy to improve the nutritional quality of milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of extruding wheat dried distillers grains with solubles with peas or canola meal on ruminal fermentation, microbial protein synthesis, nutrient digestion, and milk production in dairy cows.

PubMed

Claassen, R M; Christensen, D A; Mutsvangwa, T

2016-09-01

Our objective was to examine the effects of feeding coextruded and nonextruded supplements consisting of wheat dried distillers grains with solubles with peas (WDDGS-peas) or canola meal (WDDGS-CM) on ruminal fermentation, omasal flow, and production performance in Holstein cows. Eight cows (4 ruminally cannulated) were used in a replicated 4×4 Latin square with 28-d periods and a 2×2 factorial arrangement of dietary treatments. Dietary treatments were coextruded or nonextruded mixtures of WDDGS-peas and WDDGS-CM that were included in total mixed rations at 15.1% [dry matter (DM) basis]. Diet had no effect on DM intake. Milk yield was greater in cows fed coextruded diets compared with those fed nonextruded diets. Milk fat content was greater in cows fed nonextruded diets compared with those fed coextruded diets, but milk fat yield was greater in cows fed coextruded diets compared with those fed nonextruded diets. Milk yield tended to be greater and milk protein yield was greater in cows fed WDDGS-peas compared with those fed WDDGS-CM. Cows fed nonextruded diets had a greater milk urea-N concentration compared with those fed coextruded diets. Cows fed coextruded diets had greater ruminal digestion of DM and tended to have greater ruminal digestion of organic matter compared with those fed nonextruded diets. Total-tract digestibilities of organic matter, crude protein, ether extract, and starch were greater, whereas that of acid detergent fiber and neutral detergent fiber tended to be greater in cows fed coextruded compared with those fed nonextruded diets. Total-tract digestibility of ether extract was lower whereas that of starch was greater and that of crude protein tended to be greater in cows fed WDDGS-peas compared with those fed WDDGS-CM. Total N excretion and milk N efficiency were unaffected by diet. Ruminal NH3-N concentration tended to be greater in cows fed WDDGS-CM compared with those fed WDDGS-peas. Ruminal propionate concentration was greater whereas plasma urea-N concentration tended to be lower in cows fed coextruded compared with those fed nonextruded diets. Plasma glucose concentration was greater in cows fed diets containing WDDGS-CM compared with those fed diets containing WDDGS-peas, but the difference in plasma glucose concentration between WDDGS-CM and WDDGS-peas was greater in cows fed coextruded diets compared with those fed nonextruded diets. In summary, feeding coextruded compared with nonextruded supplements or WDDGS-peas compared WDDGS-CM increased yields of milk, fat, and protein. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Of the milk sugars, galactose, but not prebiotic galacto-oligosaccharide, improves insulin sensitivity in male Sprague-Dawley rats.

PubMed

Stahel, Priska; Kim, Julie J; Xiao, Changting; Cant, John P

2017-01-01

Consumption of dairy products reduces risk of type 2 diabetes. Milk proteins and fats exhibit anti-diabetic properties but milk sugars have been studied little in this context. Galactose from milk lactose is readily converted to glycogen in the liver but its effects on insulin sensitivity have not been assessed. Prebiotic oligosaccharides from milk alter gut microbiota and can thereby influence host metabolism. Our objective was to assess the effect on insulin sensitivity of dietary galactose compared to glucose and fructose, and fermentable galacto-oligosaccharides compared to non-fermentable methylcellulose. Diets containing 15% of dry matter from glucose, fructose, galactose, galacto-oligosaccharides, or methylcellulose were fed to 36 rats per diet for 9 weeks. Hyperinsulinemic-euglycemic clamps with [3-3H]glucose infusion and a steady-state 2-[1-14C]deoxyglucose bolus injection were used to assess insulin sensitivity and glucose uptake indices. Tissue was collected in fed, fasted and fasted, insulin-stimulated states. Galactose increased glucose infusion rate during the clamp by 53% and decreased endogenous glucose production by 57% compared to glucose and fructose. Fed-state hepatic glycogen content was greater with galactose compared to glucose and fructose, consistent with a potentiation of the insulin effect on glycogen synthase by dephosphorylation. Galactose decreased the fecal Firmicutes:Bacteroidetes ratio while galacto-oligosaccharides increased abundance of fecal Bifidobacterium spp. 481-fold compared to methylcellulose, and also increased abundance of Lactobacillus spp. and Bacteroidetes. Galacto-oligosaccharides did not affect glucose infusion rate or endogenous glucose production during basal or clamp periods compared to methylcellulose. Galactose at 15% of daily intake improved hepatic insulin sensitivity in rats compared to glucose and fructose. Galactose caused an increase in fed-state hepatic glycogen content and a favourable shift in gut microbial populations. Intake of galacto-oligosaccharides improved the gut microbial profile but did not improve insulin sensitivity.

Extracellular enzymes facilitate electron uptake in biocorrosion and bioelectrosynthesis.

PubMed

Deutzmann, Jörg S; Sahin, Merve; Spormann, Alfred M

2015-04-21

Direct, mediator-free transfer of electrons between a microbial cell and a solid phase in its surrounding environment has been suggested to be a widespread and ecologically significant process. The high rates of microbial electron uptake observed during microbially influenced corrosion of iron [Fe(0)] and during microbial electrosynthesis have been considered support for a direct electron uptake in these microbial processes. However, the underlying molecular mechanisms of direct electron uptake are unknown. We investigated the electron uptake characteristics of the Fe(0)-corroding and electromethanogenic archaeon Methanococcus maripaludis and discovered that free, surface-associated redox enzymes, such as hydrogenases and presumably formate dehydrogenases, are sufficient to mediate an apparent direct electron uptake. In genetic and biochemical experiments, we showed that these enzymes, which are released from cells during routine culturing, catalyze the formation of H2 or formate when sorbed to an appropriate redox-active surface. These low-molecular-weight products are rapidly consumed by M. maripaludis cells when present, thereby preventing their accumulation to any appreciable or even detectable level. Rates of H2 and formate formation by cell-free spent culture medium were sufficient to explain the observed rates of methane formation from Fe(0) and cathode-derived electrons by wild-type M. maripaludis as well as by a mutant strain carrying deletions in all catabolic hydrogenases. Our data collectively show that cell-derived free enzymes can mimic direct extracellular electron transfer during Fe(0) corrosion and microbial electrosynthesis and may represent an ecologically important but so far overlooked mechanism in biological electron transfer. The intriguing trait of some microbial organisms to engage in direct electron transfer is thought to be widespread in nature. Consequently, direct uptake of electrons into microbial cells from solid surfaces is assumed to have a significant impact not only on fundamental microbial and biogeochemical processes but also on applied bioelectrochemical systems, such as microbial electrosynthesis and biocorrosion. This study provides a simple mechanistic explanation for frequently observed fast electron uptake kinetics in microbiological systems without a direct transfer: free, cell-derived enzymes can interact with cathodic surfaces and catalyze the formation of intermediates that are rapidly consumed by microbial cells. This electron transfer mechanism likely plays a significant role in various microbial electron transfer reactions in the environment. Copyright © 2015 Deutzmann et al.

High efficiency vapor-fed AMTEC system for direct conversion. Appendices for final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, W.G.; Bland, J.J.

1997-05-23

This report consists of four appendices for the final report. They are: Appendix A: 700 C Vapor-Fed AMTEC Cell Calculations; Appendix B: 700 C Vapor-Fed AMTEC Cell Parts Drawings; Appendix C: 800 C Vapor-Fed AMTEC Cell Calculations; and Appendix D: 800 C Wick-Pumped AMTEC Cell System Design.

Biotransformation of furanic and phenolic compounds with hydrogen gas production in a microbial electrolysis cell

DOE PAGES

Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

2015-10-27

In this study, furanic and phenolic compounds are problematic byproducts resulting from the decomposition of lignocellulosic biomass during biofuel production. This study assessed the capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H 2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the sole carbon and energy source in the bioanode. The rate and extent of biotransformation of the five compounds, efficiency of H 2 production, as well as the anode microbial community structure were investigated. The five compoundsmore » were completely transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1,200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode coulombic efficiency was 44-69%, which is comparable to wastewater-fed MECs. The H 2 yield varied from 0.26 to 0.42 g H 2-COD/g COD removed in the anode, and the bioanode volume-normalized H 2 production rate was 0.07-0.1 L/L-d. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H 2 production were inhibited at an initial substrate concentration of 1,200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The H 2 production route demonstrated in this study has proven to be an alternative to the currently used process of reforming natural gas to supply H 2 needed to upgrade bio-oils to stable hydrocarbon fuels.« less

Biotransformation of Furanic and Phenolic Compounds with Hydrogen Gas Production in a Microbial Electrolysis Cell.

PubMed

Zeng, Xiaofei; Borole, Abhijeet P; Pavlostathis, Spyros G

2015-11-17

Furanic and phenolic compounds are problematic byproducts resulting from the breakdown of lignocellulosic biomass during biofuel production. The capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the substrate in the bioanode was assessed. The rate and extent of biotransformation of the five compounds and efficiency of H2 production, as well as the structure of the anode microbial community, were investigated. The five compounds were completely transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode Coulombic efficiency was 44-69%, which is comparable to that of wastewater-fed MECs. The H2 yield varied from 0.26 to 0.42 g H2-COD/g COD removed in the anode, and the bioanode volume-normalized H2 production rate was 0.07-0.1 L/L-d. The biotransformation of the five compounds took place via fermentation followed by exoelectrogenesis. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H2 production were inhibited at an initial substrate concentration of 1200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The MEC H2 production demonstrated in this study is an alternative to the currently used process of reforming natural gas to supply H2 needed to upgrade bio-oils to stable hydrocarbon fuels.

Effects of multistrain probiotics on growth performance, nutrient digestibility, blood profiles, faecal microbial shedding, faecal score and noxious gas emission in weaning pigs.

PubMed

Lan, R X; Lee, S I; Kim, I H

2016-12-01

This experiment was conducted to investigate the efficacy of multistrain probiotics in weaning pigs. A total of 125 28-day-old weaning pigs [(Landrace × Yorkshire) × Duroc] with an initial average body weight (BW) of 7.26 ± 0.76 kg were randomly allotted into 5 treatments, 5 replicate pens/treatment with 5 pigs/pen for 42-day experiment. Dietary treatments were as follows: CON, basal diet; PC1, CON + 0.01% multistrain probiotics; PC2, CON + 0.03% multistrain probiotics; PC3, CON + 0.06% multistrain probiotics; PC4, CON + 0.1% multistrain probiotics. On day 14, pigs fed the PC4 diet had higher BW gain than pigs fed the CON diet. On day 42, pigs fed multistrain probiotics supplementation diets had higher BW gain than pigs fed the CON diet. From days 1 to 14, pigs fed the PC2, PC3 and PC4 diets had higher (p < 0.05) ADG than pigs fed the CON diet. From day 15 to 42, pigs fed the multistrain probiotics supplementation diets had higher (p < 0.05) average daily gain (ADG) and gain: feed ratio (G:F) than pigs fed the CON diet. In the overall period, pigs fed the multistrain probiotics supplementation diets had higher (p < 0.05) ADG and pigs fed the PC2 and PC4 diets had higher (p < 0.05) G:F than pigs fed the CON diet. On day 42, pigs fed the PC4 diet had higher (p < 0.05) apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N) and gross energy (GE), faecal Lactobacillus counts and lower (p < 0.05) E. coli counts and NH 3 emission than pigs fed the CON diet. Pigs fed the multistrain probiotics supplementation diets had lower (p < 0.05) H 2 S and total mercaptans emissions than pigs fed the CON diet. Conclusions, dietary supplementation with 0.1% probiotics improved growth performance, nutrition digestibility and intestinal microflora balance and decreased faecal noxious gas emissions in weaning pigs. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Resistant Starch but Not Enzymatically Modified Waxy Maize Delays Development of Diabetes in Zucker Diabetic Fatty Rats.

PubMed

Hedemann, Mette Skou; Hermansen, Kjeld; Pedersen, Sven; Bach Knudsen, Knud Erik

2017-05-01

Background: The incidence of type 2 diabetes (T2D) is increasing worldwide, and nutritional management of circulating glucose may be a strategic tool in the prevention of T2D. Objective: We studied whether enzymatically modified waxy maize with an increased degree of branching delayed the onset of diabetes in male Zucker diabetic fatty (ZDF) rats. Methods: Forty-eight male ZDF rats, aged 5 wk, were divided into 4 groups and fed experimental diets for 9 wk that contained 52.95% starch: gelatinized corn starch (S), glucidex (GLU), resistant starch (RS), or enzymatically modified starch (EMS). Blood glucose after feed deprivation was assessed every second week; blood samples taken at run-in and at the end of the experiment were analyzed for glycated hemoglobin (HbA1c) and plasma glucose, insulin, and lipids. During weeks 2 and 8, urine was collected for metabolomic analysis. Results: Based on blood glucose concentrations in feed-deprived rats, none of the groups developed diabetes. However, in week 9, plasma glucose after feed deprivation was significantly lower in rats fed the S and RS diets (13.5 mmol/L) than in rats fed the GLU and EMS diets (17.0-18.9 mmol/L), and rats fed RS had lower HbA1c (4.9%) than rats fed the S, GLU, and EMS (5.6-6.1%) diets. The homeostasis model assessment of insulin resistance was significantly lower in rats fed RS than in rats fed the other diets (185 compared with 311-360), indicating that rats fed the S, GLU, and EMS diets were diabetic, and a 100% higher urine excretion during week 8 in rats fed the GLU and EMS diets than that of rats fed S and RS showed that they were diabetic. Urinary nontargeted metabolomics revealed that the diabetic state of rats fed S, GLU, and EMS diets influenced microbial metabolism, as well as amino acid, lipid, and vitamin metabolism. Conclusions: EMS did not delay the onset of diabetes in ZDF rats, whereas rats fed RS showed no signs of diabetes. © 2017 American Society for Nutrition.

Metabolomic signatures distinguish the impact of formula carbohydrates on disease outcome in a preterm piglet model of NEC.

PubMed

Call, Lee; Stoll, Barbara; Oosterloo, Berthe; Ajami, Nadim; Sheikh, Fariha; Wittke, Anja; Waworuntu, Rosaline; Berg, Brian; Petrosino, Joseph; Olutoye, Oluyinka; Burrin, Douglas

2018-06-19

Major risk factors for necrotizing enterocolitis (NEC) include premature birth and formula feeding in the context of microbial colonization of the gastrointestinal tract. We previously showed that feeding formula composed of lactose vs. corn syrup solids protects against NEC in preterm pigs; however, the microbial and metabolic effects of these different carbohydrates used in infant formula has not been explored. Our objective was to characterize the effects of lactose- and corn syrup solid-based formulas on the metabolic and microbial profiles of preterm piglets and to determine whether unique metabolomic or microbiome signatures correlate with severity or incidence of NEC. Preterm piglets (103 days gestation) were given total parenteral nutrition (2 days) followed by gradual (5 days) advancement of enteral feeding of formulas matched in nutrient content but containing either lactose (LAC), corn syrup solids (CSS), or 1:1 mix (MIX). Gut contents and mucosal samples were collected and analyzed for microbial profiles by sequencing the V4 region of the 16S rRNA gene. Metabolomic profiles of cecal contents and plasma were analyzed by LC/GC mass spectrometry. NEC incidence was 14, 50, and 44% in the LAC, MIX, and CSS groups, respectively. The dominant classes of bacteria were Bacilli, Clostridia, and Gammaproteobacteria. The number of observed OTUs was lowest in colon contents of CSS-fed pigs. CSS-based formula was associated with higher Bacilli and lower Clostridium from clusters XIVa and XI in the colon. NEC was associated with decreased Gammaproteobacteria in the stomach and increased Clostridium sensu stricto in the ileum. Plasma from NEC piglets was enriched with metabolites of purine metabolism, aromatic amino acid metabolism, and bile acids. Markers of glycolysis, e.g., lactate, were increased in the cecal contents of CSS-fed pigs and in plasma of pigs which developed NEC. Feeding formula containing lactose is not completely protective against NEC, yet selects for greater microbial richness associated with changes in Bacilli and Clostridium and lower NEC incidence. We conclude that feeding preterm piglets a corn syrup solid vs. lactose-based formula increases the incidence of NEC and produces distinct metabolomic signatures despite modest changes in microbiome profiles.

Electricity generation from an inorganic sulfur compound containing mining wastewater by acidophilic microorganisms.

PubMed

Ni, Gaofeng; Christel, Stephan; Roman, Pawel; Wong, Zhen Lim; Bijmans, Martijn F M; Dopson, Mark

2016-09-01

Sulfide mineral processing often produces large quantities of wastewaters containing acid-generating inorganic sulfur compounds. If released untreated, these wastewaters can cause catastrophic environmental damage. In this study, microbial fuel cells were inoculated with acidophilic microorganisms to investigate whether inorganic sulfur compound oxidation can generate an electrical current. Cyclic voltammetry suggested that acidophilic microorganisms mediated electron transfer to the anode, and that electricity generation was catalyzed by microorganisms. A cation exchange membrane microbial fuel cell, fed with artificial wastewater containing tetrathionate as electron donor, reached a maximum whole cell voltage of 72 ± 9 mV. Stepwise replacement of the artificial anolyte with real mining process wastewater had no adverse effect on bioelectrochemical performance and generated a maximum voltage of 105 ± 42 mV. 16S rRNA gene sequencing of the microbial consortia resulted in sequences that aligned within the genera Thermoplasma, Ferroplasma, Leptospirillum, Sulfobacillus and Acidithiobacillus. This study opens up possibilities to bioremediate mining wastewater using microbial fuel cell technology. Copyright © 2016 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Substrate removal and electricity generation in a membrane-less microbial fuel cell for biological treatment of wastewater.

PubMed

Wang, Haiping; Jiang, Sunny C; Wang, Yun; Xiao, Bo

2013-06-01

Microbial fuel cells have gained popularity in recent years due to its promise in converting organic wastewater into renewable electrical energy. In this study, a membrane-less MFC with a biocathode was developed to evaluate its performance in electricity generation while simultaneously treating wastewater. The MFC fed with a continuous flow of 2g/day acetate produced a power density of 30 mW/m(2) and current density of 245 mA/m(2). A substrate degradation efficiency (SDE) of 75.9% was achieved with 48.7% attributed to the anaerobic process and 27.2% to the aerobic process. Sequencing analysis of the microbial consortia using 16S rDNA pryosequencing showed the predominance of Bacteroidia in the anode after one month of operation, while the microbial community in the cathode chamber was dominated by Gamma-proteobacteria and Beta-proteobacteria. Coulombic efficiencies varied from 19.8% to 58.1% using different acetate concentrations, indicating power density can be further improved through the accumulation of electron-transferring bacteria. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of separator and inoculum type on electricity generation and microbial community in single-chamber microbial fuel cells.

PubMed

Yu, Jaecheul; Park, Younghyun; Lee, Taeho

2014-04-01

Single-chamber microbial fuel cell (SMFC)-I consisted of 4 separator-electrode assemblies (SEAs) with two types of cation exchange membrane (CEM: Nafion and CMI 7000) and an anion exchange membrane (AEM: AMI 7001). SMFC-II consisted of 4 SEAs with Nafion and three types of nonwoven fabric. SMFC-I and -II were inoculated with anaerobic digested and activated sludge, respectively, and operated under fed-batch mode. In SMFC I, AEM-SEA showed a maximum power density (PDmax). Nafion-SEA showed a PDmax in SMFC II, which was similar to that of Nafion-SEA of SMFC I. Although different bacteria were developed in SMFC-I (Deltaproteobacteria and Firmicutes) and SMFC-II (Gammaproteobacteria, Betaproteobacteria and Bacteroidetes), the inoculum type little affects electricity generation. Variations of pH and oxygen in biofilm have influenced microbial community structure and electricity generation according to the electrode and separator material. Although the electricity generation of non-woven fabric-SEA was less than that of Nafion-SEA, the use of non-woven fabrics is expected to reduce the construction and operating costs of MFCs.

Adaptations in bacterial catabolic enzyme activity and community structure in membrane-coupled bioreactors fed simple synthetic wastewater.

PubMed

LaPara, Timothy M; Klatt, Christian G; Chen, Ruoyu

2006-02-10

Membrane-coupled bioreactors (MBRs) offer substantial benefits compared to conventional reactor designs for biological wastewater treatment. MBR treatment efficiency, however, has not been optimized because the effects of the MBR on process microbiology are poorly understood. In this study, the structure and function of the microbial communities growing in MBRs fed simple synthetic wastewater were investigated. In four starch-fed MBRs, the bacterial community substantially increased its alpha-glucosidase affinity (>1000-fold), while the leucine aminopeptidase and heptanoate esterase affinities increased slightly (<40-fold) or remained relatively constant. Concomitant to these physiological adaptations, shifts in the bacterial community structure in two of the starch-fed MBRs were detected by PCR-DGGE. Four of the bacterial populations detected by PCR-DGGE were isolated and exhibited specific growth rates in batch culture ranging from 0.009 to 0.22 h(-1). Our results suggest that bacterial communities growing under increasingly stringent nutrient limitation adapt their enzyme activities primarily for the nutrients provided, but that there is also a more subtle response not linked to the substrates included in the feed medium. Our research also demonstrates that MBRs can support relatively complex bacterial communities even on simple feed media.

Comparison of microbial growth inhibition screening assays with high-pressure liquid chromatography for detection of experimentally incurred penicillin G residues in calves.

PubMed

Musser, Jeffrey M B; Anderson, Kevin L; Boison, Joe O

2002-01-01

Twelve calves were fed milk replacer containing 3.33 ppm penicillin G for one feeding, and 12 calves were fed the medicated milk replacer once daily at a rate of 12% of their body weight for 14 days. Two calves served as controls. Calves were slaughtered 4 to 13 hours after being fed. Kidney, liver, muscle, and urine samples were assayed for penicillin by high-pressure liquid chromatography (HPLC). Penicillin G was not detected in any muscle samples and concentrations of penicillin exceeded the tolerance level (0.05 microg/g) in kidney or liver tissue from 13 of 24 treated-calf carcasses examined by HPLC. The Live Animal Swab Test identified all 13 carcasses with violative drug residues. Using kidney as the test matrix, the Swab Test on Premises identified 10 of 13 carcasses with violative drug residues, while the Calf Antibiotic Sulfa Test identified seven of 13 carcasses with violative residues.

Methanogenic community shifts during the transition from sewage mono-digestion to co-digestion of grass biomass.

PubMed

Hardegen, Justus; Latorre-Pérez, Adriel; Vilanova, Cristina; Günther, Thomas; Porcar, Manuel; Luschnig, Olaf; Simeonov, Claudia; Abendroth, Christian

2018-06-06

In this work, liquid and solid fractions of grass biomass were used as co-substrates for anaerobic co-digestion of sewage sludge. The input of grass biomass was increased gradually, and the underlying methanogenic microbiome was assessed by means of microscopy-based cell counting and full-length 16S rRNA gene high-throughput sequencing, proving for the first time the suitability of nanopore-based portable sequencers as a monitoring tool for anaerobic digestion systems. In both cases co-fermentation resulted in an increased number of bacteria and methanogenic archaea. Interestingly, the microbial communities were highly different between solid and liquid-fed batches. Liquid-fed batches developed a more stable microbiome, enriched in Methanosarcina spp., and resulted in higher methanogenic yield. In contrast, solid-fed batches were highly unstable at higher substrate concentrations, and kept Methanosaeta spp. - typically associated to sewage sludge - as the majoritary methanogenic archaea. Copyright © 2018 Elsevier Ltd. All rights reserved.

Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate.

PubMed

Hari, Ananda Rao; Katuri, Krishna P; Gorron, Eduardo; Logan, Bruce E; Saikaly, Pascal E

2016-07-01

Microbial electrolysis cells (MECs) provide a viable approach for bioenergy generation from fermentable substrates such as propionate. However, the paths of electron flow during propionate oxidation in the anode of MECs are unknown. Here, the paths of electron flow involved in propionate oxidation in the anode of two-chambered MECs were examined at low (4.5 mM) and high (36 mM) propionate concentrations. Electron mass balances and microbial community analysis revealed that multiple paths of electron flow (via acetate/H2 or acetate/formate) to current could occur simultaneously during propionate oxidation regardless of the concentration tested. Current (57-96 %) was the largest electron sink and methane (0-2.3 %) production was relatively unimportant at both concentrations based on electron balances. At a low propionate concentration, reactors supplemented with 2-bromoethanesulfonate had slightly higher coulombic efficiencies than reactors lacking this methanogenesis inhibitor. However, an opposite trend was observed at high propionate concentration, where reactors supplemented with 2-bromoethanesulfonate had a lower coulombic efficiency and there was a greater percentage of electron loss (23.5 %) to undefined sinks compared to reactors without 2-bromoethanesulfonate (11.2 %). Propionate removal efficiencies were 98 % (low propionate concentration) and 78 % (high propionate concentration). Analysis of 16S rRNA gene pyrosequencing revealed the dominance of sequences most similar to Geobacter sulfurreducens PCA and G. sulfurreducens subsp. ethanolicus. Collectively, these results provide new insights on the paths of electron flow during propionate oxidation in the anode of MECs fed with low and high propionate concentrations.

Prebiotic milk oligosaccharides prevent development of obese phenotype, impairment of gut permeability, and microbial dysbiosis in high fat-fed mice.

PubMed

Hamilton, M Kristina; Ronveaux, Charlotte C; Rust, Bret M; Newman, John W; Hawley, Melissa; Barile, Daniela; Mills, David A; Raybould, Helen E

2017-05-01

Microbial dysbiosis and increased intestinal permeability are targets for prevention or reversal of weight gain in high-fat (HF) diet-induced obesity (DIO). Prebiotic milk oligosaccharides (MO) have been shown to benefit the host intestine but have not been used in DIO. We hypothesized that supplementation with bovine MO would prevent the deleterious effect of HF diet on the gut microbiota and intestinal permeability and attenuate development of the obese phenotype. C57BL/6 mice were fed a control diet, HF (40% fat/kcal), or HF + prebiotic [6%/kg bovine milk oligosaccharides (BMO) or inulin] for 1, 3, or 6 wk. Gut microbiota and intestinal permeability were assessed in the ileum, cecum, and colon. Addition of BMO to the HF diet significantly attenuated weight gain, decreased adiposity, and decreased caloric intake; inulin supplementation also lowered weight gain and adiposity, but this did not reach significance. BMO and inulin completely abolished the HF diet-induced increase in paracellular and transcellular permeability in the small and large intestine. Both BMO and inulin increased abundance of beneficial microbes Bifidobacterium and Lactobacillus in the ileum. However, inulin supplementation altered phylogenetic diversity and decreased species richness. We conclude that addition of BMO to the HF diet completely prevented increases in intestinal permeability and microbial dysbiosis and was partially effective to prevent weight gain in DIO. NEW & NOTEWORTHY This study provides the first report of the effects of prebiotic bovine milk oligosaccharides on the host phenotype of high-fat diet-induced obesity in mice. Copyright © 2017 the American Physiological Society.

Prebiotic milk oligosaccharides prevent development of obese phenotype, impairment of gut permeability, and microbial dysbiosis in high fat-fed mice

PubMed Central

Ronveaux, Charlotte C.; Rust, Bret M.; Newman, John W.; Hawley, Melissa; Barile, Daniela; Mills, David A.

2017-01-01

Microbial dysbiosis and increased intestinal permeability are targets for prevention or reversal of weight gain in high-fat (HF) diet-induced obesity (DIO). Prebiotic milk oligosaccharides (MO) have been shown to benefit the host intestine but have not been used in DIO. We hypothesized that supplementation with bovine MO would prevent the deleterious effect of HF diet on the gut microbiota and intestinal permeability and attenuate development of the obese phenotype. C57BL/6 mice were fed a control diet, HF (40% fat/kcal), or HF + prebiotic [6%/kg bovine milk oligosaccharides (BMO) or inulin] for 1, 3, or 6 wk. Gut microbiota and intestinal permeability were assessed in the ileum, cecum, and colon. Addition of BMO to the HF diet significantly attenuated weight gain, decreased adiposity, and decreased caloric intake; inulin supplementation also lowered weight gain and adiposity, but this did not reach significance. BMO and inulin completely abolished the HF diet-induced increase in paracellular and transcellular permeability in the small and large intestine. Both BMO and inulin increased abundance of beneficial microbes Bifidobacterium and Lactobacillus in the ileum. However, inulin supplementation altered phylogenetic diversity and decreased species richness. We conclude that addition of BMO to the HF diet completely prevented increases in intestinal permeability and microbial dysbiosis and was partially effective to prevent weight gain in DIO. NEW & NOTEWORTHY This study provides the first report of the effects of prebiotic bovine milk oligosaccharides on the host phenotype of high-fat diet-induced obesity in mice. PMID:28280143

Effect of supplementing orchardgrass herbage with a total mixed ration or flaxseed fermentation profile and bacterial protein synthesis in continuous culture

USDA-ARS?s Scientific Manuscript database

A 4-unit dual-flow continuous culture fermentor system was used to evaluate the effects of herbage, a total mixed ration (TMR) and flaxseed on nutrient digestibility and microbial N synthesis. Treatments were randomly assigned to fermentors in a 4 x 4 Latin square design. Each fermentor was fed a to...

Development of an Acetate- or Sugar-fed Microbial Power Generator for Military Bases

DTIC Science & Technology

2012-07-01

Lovley, L. M. Tender, Energy Environ. Sci. 2011, 4, 896–913. [10] a) E. F. Dalton, N. A. Surridge, J. C. Jernigan, K. O. Wilbourn , J. S. Facci, R. W...Microbiol. 2010, 76, 3999–4007; b) X. L. Qian, T. Mester, L. Morgado, T. Arakawa, M. L. Sharma, K. Inoue, C. Joseph , C. A. Salgueiro, M. J. Maroney, D

Effect of high and low roughage total mixed ration diets on rumen metabolites and enzymatic profiles in crossbred cattle and buffaloes

PubMed Central

Sinha, S. K.; Chaturvedi, V. B.; Singh, Putan; Chaudhary, L. C.; Ghosh, Mayukh; Shivani, Swati

2017-01-01

Aim:: A comparative study was conducted on crossbred cattle and buffaloes to investigate the effect of feeding high and low roughage total mixed ration (TMR) diets on rumen metabolites and enzymatic profiles. Materials and Methods:: Three rumen-fistulated crossbred cattle and buffalo were randomly assigned as per 3×3 switch over design for 21-days. Three TMR diets consisting of concentrate mixture, wheat straw and green maize fodder in the ratios of (T1) 60:20:20, (T2) 40:30:30, and (T3) 20:40:40, respectively, were fed to the animals ad libitum. Rumen liquor samples were collected at 0, 2, 4, 6, and 8 h post feeding for the estimation of rumen biochemical parameters on 2 consecutive days in each trial. Results:: The lactic acid concentration and pH value were comparable in both species and treatments. Feed intake (99.77±2.51 g/kg body weight), ruminal ammonia nitrogen, and total nitrogen were significantly (p<0.05) higher in buffalo and in treatment group fed with high concentrate diet. Production of total volatile fatty acids (VFAs) was non-significant (p>0.05) among treatments and significantly (p<0.05) greater in crossbred cattle than buffaloes. Molar proportions of individual VFAs propionate (C3), propionate:butyrate (C3:C4), and (acetate+butyrate):propionate ([C2+C4]:C3) ratio in both crossbred cattle and buffalo were not affected by high or low roughage diet, but percentage of acetate and butyrate varied significantly (p<0.05) among treatment groups. Activities of microbial enzymes were comparable among species and different treatment groups. A total number of rumen protozoa were significantly (p<0.05) higher in crossbred cattle than buffaloes along with significantly (p<0.05) higher population in animal fed with high concentrate diet (T1). Conclusion:: Rumen microbial population and fermentation depend on constituents of the treatment diet. However, microbial enzyme activity remains similar among species and different treatments. High concentrate diet increases number of rumen protozoa, and the number is higher in crossbred cattle than buffaloes. PMID:28717312

Effects of diets containing different concentrations of mannanoligosaccharide or antibiotics on growth performance, intestinal development, cecal and litter microbial populations, and carcass parameters of broilers.

PubMed

Baurhoo, B; Ferket, P R; Zhao, X

2009-11-01

The effects of 2 levels of mannanoligosaccharide (MOS) in feed were compared with antibiotic growth promoters on growth performance, intestinal morphology, cecal and litter microbial populations, and carcass parameters in broilers raised in a sanitary environment. Dietary treatments included: 1) antibiotic growth promoter-free diet (control), 2) VIRG (diet 1 + 16.5 mg/kg of virginiamycin), 3) BACT (diet 1 + 55 mg/kg of bacitracin), 4) LMOS (diet 1 + 0.2% MOS), and 5) HMOS (diet 1 + 0.5% MOS). Birds were randomly assigned to 3 replicate pens/treatment (n = 55/pen). Body weight and feed intake were recorded weekly throughout 38 d. At d 14, 24, and 34, a 1-cm segment of duodenum, jejunum, and ileum was used in morphological analysis (n = 9 birds/d per treatment). At the same bird ages, cecal contents were assayed for lactobacilli, bifidobacteria, Salmonella, Campylobacter, and Escherichia coli, whereas litter was analyzed for Salmonella, Campylobacter, and E. coli. Carcass yields (breast fillet and tenders, thigh, drumstick, and wing) were determined at d 38. Body weight, feed conversion, and carcass yields did not differ among treatments. In contrast to birds fed VIRG or BACT, LMOS and HMOS consistently increased (P < 0.05) villi height and goblet cell number per villus in all intestinal segments at d 24 and 34. Bifidobacteria concentrations were higher (P < 0.05) in LMOS- and HMOS-fed birds at all time points. Birds and litter from all treatments were free of Salmonella. At d 14 and 24, cecal E. coli and Campylobacter counts were not different among treatments. In comparison to birds fed control, at d 34, BACT, LMOS, and HMOS significantly reduced (P < 0.05) cecal E. coli concentrations, whereas Campylobacter counts were reduced (P < 0.05) by VIRG, BACT, and LMOS. Litter bacterial counts were not altered by dietary treatments. In conclusion, under conditions of this study, MOS conferred intestinal health benefits to chickens by improving its morphological development and microbial ecology. But, there were no additional benefits of the higher MOS dosage.

Nutrient intake, digestibility and performance of Gaddi kids supplemented with tea seed or tea seed saponin extract.

PubMed

Kumar, M; Kannan, A; Bhar, R; Gulati, A; Gaurav, A; Sharma, V K

2017-04-01

An experiment was conducted to determine the nutrient intake, digestibility, microbial protein synthesis, haemato-biochemical attributes, immune response and growth performance of Gaddi kids fed with oat fodder based basal diet supplemented with either tea seed or tea seed saponin (TSS) extract. Eighteen male kids, 7.03±0.16 months of age and 19.72±0.64 kg body weight, were distributed into three groups, T 0 (control), T 1 , and T 2 , consisting of 6 animals each in a completely randomized design. The kids were fed a basal diet consisting of concentrate mixture and oat fodder (50:50). Animals in group III (T 2 ) were supplemented with TSS at 0.4% of dry matter intake (DMI), and group II (T 1 ) were supplemented with tea seed at 2.6% of DMI to provide equivalent dose of TSS as in T 2 . Two metabolism trials were conducted, 1st after 21 days and 2nd after 90 days of feeding to evaluate the short term and long term effects of supplementation. The tea seed (T 1 ) or TSS (T 2 ) supplementation did not affect DMI as well as the digestibility of dry matter, organic matter, crude protein, neutral detergent fibre, and acid detergent fibre. Nutritive value of diet and plane of nutrition were also comparable for both the periods. However, the average daily gain and feed conversion ratio (FCR) were improved (p<0.05) for T 1 and T 2 as compared to T 0 . The microbial protein supply was also higher (p<0.05) for T 1 and T 2 for both the periods. There was no effect of supplementation on most blood parameters. However, the triglyceride and low density lipoprotein cholesterol levels decreased (p<0.05) and high density lipoprotein-cholesterol level increased (p<0.05) in T 2 as compared with T 0 and T 1 . Supplementation also did not affect the cell mediated and humoral immune response in goats. Tea seed at 2.6% of DMI and TSS at 0.4% DMI can be fed to Gaddi goats to improve growth rate, FCR and microbial protein synthesis.

Biogas Production from Protein-Rich Biomass: Fed-Batch Anaerobic Fermentation of Casein and of Pig Blood and Associated Changes in Microbial Community Composition

PubMed Central

Kovács, Etelka; Wirth, Roland; Maróti, Gergely; Bagi, Zoltán; Rákhely, Gábor; Kovács, Kornél L.

2013-01-01

It is generally accepted as a fact in the biogas technology that protein-rich biomass substrates should be avoided due to inevitable process inhibition. Substrate compositions with a low C/N ratio are considered difficult to handle and may lead to process failure, though protein-rich industrial waste products have outstanding biogas generation potential. This common belief has been challenged by using protein-rich substrates, i.e. casein and precipitated pig blood protein in laboratory scale continuously stirred mesophilic fed-batch biogas fermenters. Both substrates proved suitable for sustained biogas production (0.447 L CH4/g protein oDM, i.e. organic total solids) in high yield without any additives, following a period of adaptation of the microbial community. The apparent key limiting factors in the anaerobic degradation of these proteinaceous materials were the accumulation of ammonia and hydrogen sulfide. Changes in time in the composition of the microbiological community were determined by next-generation sequencing-based metagenomic analyses. Characteristic rearrangements of the biogas-producing community upon protein feeding and specific differences due to the individual protein substrates were recognized. The results clearly demonstrate that sustained biogas production is readily achievable, provided the system is well-characterized, understood and controlled. Biogas yields (0.45 L CH4/g oDM) significantly exceeding those of the commonly used agricultural substrates (0.25-0.28 L CH4/g oDM) were routinely obtained. The results amply reveal that these high-energy-content waste products can be converted to biogas, a renewable energy carrier with flexible uses that can replace fossil natural gas in its applications. Process control, with appropriate acclimation of the microbial community to the unusual substrate, is necessary. Metagenomic analysis of the microbial community by next-generation sequencing allows a precise determination of the alterations in the community composition in the course of the process. PMID:24146974

Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets.

PubMed

Luo, Guobin; Xu, Wenbin; Yang, Jinshan; Li, Yang; Zhang, Liyang; Wang, Yizhen; Lin, Cong; Zhang, Yonggen

2017-05-01

This trial was performed to examine the effects of ruminally degradable starch (RDS) levels in total mixed ration (TMR) with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Eight multiparous Holstein cows (body weight [BW]: 717±63 kg; days in milk [DIM]: 169±29) were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS) or 72.1% ruminally degradable starch (% of total starch, high RDS). Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

Comparative Metagenomic Analysis of Electrogenic Microbial Communities in Differentially Inoculated Swine Wastewater-Fed Microbial Fuel Cells

PubMed Central

Sorokin, Anatoly A.; Kiseleva, Larisa; Simpson, David J. W.; Fedorovich, V.; Sharipova, Margarita R.; Kainuma, Mami; Cohen, Michael F.; Goryanin, Igor

2017-01-01

Bioelectrochemical systems such as microbial fuel cells (MFCs) are promising new technologies for efficient removal of organic compounds from industrial wastewaters, including that generated from swine farming. We inoculated two pairs of laboratory-scale MFCs with sludge granules from a beer wastewater-treating anaerobic digester (IGBS) or from sludge taken from the bottom of a tank receiving swine wastewater (SS). The SS-inoculated MFC outperformed the IGBS-inoculated MFC with regard to COD and VFA removal and electricity production. Using a metagenomic approach, we describe the microbial diversity of the MFC planktonic and anodic communities derived from the different inocula. Proteobacteria (mostly Deltaproteobacteria) became the predominant phylum in both MFC anodic communities with amplification of the electrogenic genus Geobacter being the most pronounced. Eight dominant and three minor species of Geobacter were found in both MFC anodic communities. The anodic communities of the SS-inoculated MFCs had a higher proportion of Clostridium and Bacteroides relative to those of the IGBS-inoculated MFCs, which were enriched with Pelobacter. The archaeal populations of the SS- and IGBS-inoculated MFCs were dominated by Methanosarcina barkeri and Methanothermobacter thermautotrophicus, respectively. Our results show a long-term influence of inoculum type on the performance and microbial community composition of swine wastewater-treating MFCs. PMID:29158944

Outward electron transfer by Saccharomyces cerevisiae monitored with a bi-cathodic microbial fuel cell-type activity sensor.

PubMed

Ducommun, Raphaël; Favre, Marie-France; Carrard, Delphine; Fischer, Fabian

2010-03-01

A Janus head-like bi-cathodic microbial fuel cell was constructed to monitor the electron transfer from Saccharomyces cerevisiae to a woven carbon anode. The experiments were conducted during an ethanol cultivation of 170 g/l glucose in the presence and absence of yeast-peptone medium. First, using a basic fuel-cell type activity sensor, it was shown that yeast-peptone medium contains electroactive compounds. For this purpose, 1% solutions of soy peptone and yeast extract were subjected to oxidative conditions, using a microbial fuel cell set-up corresponding to a typical galvanic cell, consisting of culture medium in the anodic half-cell and 0.5 M K(3)Fe(CN)(6) in the cathodic half-cell. Second, using a bi-cathodic microbial fuel cell, it was shown that electrons were transferred from yeast cells to the carbon anode. The participation of electroactive compounds in the electron transport was separated as background current. This result was verified by applying medium-free conditions, where only glucose was fed, confirming that electrons are transferred from yeast cells to the woven carbon anode. Knowledge about the electron transfer through the cell membrane is of importance in amperometric online monitoring of yeast fermentations and for electricity production with microbial fuel cells. Copyright (c) 2009 John Wiley & Sons, Ltd.

Link between microbial composition and carbon substrate-uptake preferences in a PHA-storing community

PubMed Central

Albuquerque, Maria G E; Carvalho, Gilda; Kragelund, Caroline; Silva, Ana F; Barreto Crespo, Maria T; Reis, Maria A M; Nielsen, Per H

2013-01-01

The microbial community of a fermented molasses-fed sequencing batch reactor (SBR) operated under feast and famine conditions for production of polyhydroxyalkanoates (PHAs) was identified and quantified through a 16 S rRNA gene clone library and fluorescence in situ hybridization (FISH). The microbial enrichment was found to be composed of PHA-storing populations (84% of the microbial community), comprising members of the genera Azoarcus, Thauera and Paracoccus. The dominant PHA-storing populations ensured the high functional stability of the system (characterized by high PHA-storage efficiency, up to 60% PHA content). The fermented molasses contained primarily acetate, propionate, butyrate and valerate. The substrate preferences were determined by microautoradiography-FISH and differences in the substrate-uptake capabilities for the various probe-defined populations were found. The results showed that in the presence of multiple substrates, microbial populations specialized in different substrates were selected, thereby co-existing in the SBR by adapting to different niches. Azoarcus and Thauera, primarily consumed acetate and butyrate, respectively. Paracoccus consumed a broader range of substrates and had a higher cell-specific substrate uptake. The relative species composition and their substrate specialization were reflected in the substrate removal rates of different volatile fatty acids in the SBR reactor. PMID:22810062

Microbial community dynamics and biogas production from manure fractions in sludge bed anaerobic digestion.

PubMed

Nordgård, A S R; Bergland, W H; Bakke, R; Vadstein, O; Østgaard, K; Bakke, I

2015-12-01

To elucidate how granular sludge inoculum and particle-rich organic loading affect the structure of the microbial communities and process performance in upflow anaerobic sludge bed (UASB) reactors. We investigated four reactors run on dairy manure filtrate and four on pig manure supernatant for three months achieving similar methane yields. The reactors fed with less particle rich pig manure stabilized faster and had highest capacity. Microbial community dynamics analysed by a PCR/denaturing gradient gel electrophoresis approach showed that influent was a major determinant for the composition of the reactor communities. Comparisons of pre- and non-adapted inoculum in the reactors run on pig manure supernatant showed that the community structure of the nonadapted inoculum adapted in approximately two months. Microbiota variance partitioning analysis revealed that running time, organic loading rate and inoculum together explained 26 and 31% of the variance in bacterial and archaeal communities respectively. The microbial communities of UASBs adapted to the reactor conditions in treatment of particle rich manure fractions, obtaining high capacity, especially on pig manure supernatant. These findings provide relevant insight into the microbial community dynamics in startup and operation of sludge bed reactors for methane production from slurry fractions, a major potential source of biogas. © 2015 The Society for Applied Microbiology.

Diversity of the Sediment Microbial Community in the Aha Watershed (Southwest China) in Response to Acid Mine Drainage Pollution Gradients

PubMed Central

Sun, Weimin; Sun, Min; Dong, Yiran; Ning, Zengping; Xiao, Enzong; Tang, Song; Li, Jiwei

2015-01-01

Located in southwest China, the Aha watershed is continually contaminated by acid mine drainage (AMD) produced from upstream abandoned coal mines. The watershed is fed by creeks with elevated concentrations of aqueous Fe (total Fe > 1 g/liter) and SO42− (>6 g/liter). AMD contamination gradually decreases throughout downstream rivers and reservoirs, creating an AMD pollution gradient which has led to a suite of biogeochemical processes along the watershed. In this study, sediment samples were collected along the AMD pollution sites for geochemical and microbial community analyses. High-throughput sequencing found various bacteria associated with microbial Fe and S cycling within the watershed and AMD-impacted creek. A large proportion of Fe- and S-metabolizing bacteria were detected in this watershed. The dominant Fe- and S-metabolizing bacteria were identified as microorganisms belonging to the genera Metallibacterium, Aciditerrimonas, Halomonas, Shewanella, Ferrovum, Alicyclobacillus, and Syntrophobacter. Among them, Halomonas, Aciditerrimonas, Metallibacterium, and Shewanella have previously only rarely been detected in AMD-contaminated environments. In addition, the microbial community structures changed along the watershed with different magnitudes of AMD pollution. Moreover, the canonical correspondence analysis suggested that temperature, pH, total Fe, sulfate, and redox potentials (Eh) were significant factors that structured the microbial community compositions along the Aha watershed. PMID:25979900

Improvement of a microbial fuel cell performance as a BOD sensor using respiratory inhibitors.

PubMed

Chang, In Seop; Moon, Hyunsoo; Jang, Jae Kyung; Kim, Byung Hong

2005-03-15

Studies were made to improve the performance of a microbial fuel cell (MFC) as a biochemical oxygen demand (BOD) sensor. The signal from MFCs decreased in the presence of electron acceptors of higher redox potential such as nitrate and oxygen. The addition of azide and cyanide did not change the signal in the absence of the electron acceptors. The respiratory inhibitors eliminated the inhibitory effects of the electron acceptors on the current generation from MFCs. Similar results were obtained using oligotrophic MFCs fed with an environmental sample that contained nitrate. The use of the respiratory inhibitors is therefore recommended for the accurate BOD measurement of environmental samples containing nitrate and/or oxygen with an MFC-type BOD sensor.

Biome engineering-2020.

PubMed

Brüssow, Harald

2016-09-01

The gut microbiome research is going from a descriptive into an intervention phase. To optimize beneficial microbe-host interaction, we need to understand how to steer the system by modulating the nutrient input with which the system is literally fed (e.g. diets, fibres, prebiotics, human milk oligosaccharides), and we must learn how to modulate the composition of the gut microbiota by adding beneficial microbes (e.g. probiotics, faecal transplants) and by eliminating disturbing microbial members using, for example, bacteriophages in this highly complex ecosystem. The current status of the field is reviewed together with an outlook what might be expected until 2020, highlighting obstacles to progress and possible solutions to these problems. © 2016 The Author. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Metagenomics analysis of gut microbiota and immune modulation in zebrafish (Danio rerio) fed chitosan silver nanocomposites.

PubMed

Udayangani, R M C; Dananjaya, S H S; Nikapitiya, Chamilani; Heo, Gang-Joon; Lee, Jehee; De Zoysa, Mahanama

2017-07-01

In this study, we evaluated the effects of chitosan silver nanocomposites (CAgNCs) supplemented diet on gut microbial community, goblet cell density, gut morphometry and mRNA expression of immune related and mucin encoding genes in zebrafish. Zebrafish gut microbiota analysis results clearly showed the reduction of phylum Proteobacteria. However, they remained as the major bacterial group in gut with CAgNCs supplemented diet, while the abundance of phylum Fusobacteria and phylum Bacteroidetes were increased notably compared to the control diet fed fish. Total goblet cell density was significantly increased at 30 and 60 days in CAgNCs supplemented group (1.6-fold and 2.0-fold, respectively) compared to the control group indicating enhanced immune function in the gut. CAgNCs supplementation has also increased villi height significantly in the zebrafish mid gut at the end of 30 (95.5 ± 3.7 μm) and 60 days (144.40 ± 4.8 μm) compared to control diet fed fish at 30 (86.90 ± 3.7 μm) and 60 days (96.2 ± 4.8 μm). Furthermore, mRNA expression of immune related genes such as TNF-α (6.2-fold), IL-10 (5.0-fold), IL-12 (9.2-fold), IRF-1 (5.2-fold), Defbl1 (3-fold), Lyz (5.1-fold) and mucin encoding genes were significantly upregulated (above 2-fold) compared to that of control group. The current study revealed that CAgNCs supplemented diet engenders promising effects on fish gut immunity by enhancing beneficial microbial populations, goblet cell density, villi length, and transcriptional regulation of immune related and mucin encoding genes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Illumina Miseq platform analysis caecum bacterial communities of rex rabbits fed with different antibiotics.

PubMed

Zou, Fuqin; Zeng, Dong; Wen, Bin; Sun, Hao; Zhou, Yi; Yang, Mingyue; Peng, Zhirong; Xu, Shuai; Wang, Hesong; Fu, Xiangchao; Du, Dan; Zeng, Yan; Zhu, Hui; Pan, Kangcheng; Jing, Bo; Wang, Ping; Ni, Xueqin

2016-12-01

Antibiotics have been widely used for the prevention and the treatment of diseases to humans and animals, and they have fed additives for agricultural animals to promote growth. However, there is a growing concern over the practice due to its side effects on intestinal microbial communities which plays a vital role in animals' health. To investigate the effect of antibiotics on the bacterial population of the caecum in rex rabbits, 80 rex rabbits were randomly divided into four groups: control group (B, basal diet), chlortetracycline group (C, 50 mg/kg), colistin sulfate group (S, 20 mg/kg) and zinc bacitracin group (Z, 40 mg/kg). Caecum microbial communities of rex rabbits from the four groups were analyzed through Illumina Miseq platform after being fed 28 days. The results showed that most obtained sequences belongs to Firmicutes followed by Bacteroidetes, and the ratio of Bacteroidetes/Firmicutes in C group (42.31 %) was higher than that in Z group (21.84 %). Zinc bacitracin supplementation caused a significant decreased of the Proteobacteria phylum and Lactobacillus spp. (P < 0.05), while the Lactobacillus spp. significantly increased in S group (P < 0.05). In addition, Ruminococcus spp., especially Ruminococcus albus were the predominant bacterial species found in both S and Z groups. The proportion of Coprococcus spp. significantly increased in Z group (P < 0.05). These findings suggested that the antibiotics used may cause significant changes in the caecum microbiota of rex rabbits, and we also found C group had a similarity caecum bacteria structure with B group which was probably due to the high levels of chlortetracycline resistance.

The effect of feed water dissolved organic carbon concentration and composition on organic micropollutant removal and microbial diversity in soil columns simulating river bank filtration.

PubMed

Bertelkamp, C; van der Hoek, J P; Schoutteten, K; Hulpiau, L; Vanhaecke, L; Vanden Bussche, J; Cabo, A J; Callewaert, C; Boon, N; Löwenberg, J; Singhal, N; Verliefde, A R D

2016-02-01

This study investigated organic micropollutant (OMP) biodegradation rates in laboratory-scale soil columns simulating river bank filtration (RBF) processes. The dosed OMP mixture consisted of 11 pharmaceuticals, 6 herbicides, 2 insecticides and 1 solvent. Columns were filled with soil from a RBF site and were fed with four different organic carbon fractions (hydrophilic, hydrophobic, transphilic and river water organic matter (RWOM)). Additionally, the effect of a short-term OMP/dissolved organic carbon (DOC) shock-load (e.g. quadrupling the OMP concentrations and doubling the DOC concentration) on OMP biodegradation rates was investigated to assess the resilience of RBF systems. The results obtained in this study imply that - in contrast to what is observed for managed aquifer recharge systems operating on wastewater effluent - OMP biodegradation rates are not affected by the type of organic carbon fraction fed to the soil column, in case of stable operation. No effect of a short-term DOC shock-load on OMP biodegradation rates between the different organic carbon fractions was observed. This means that the RBF site simulated in this study is resilient towards transient higher DOC concentrations in the river water. However, a temporary OMP shock-load affected OMP biodegradation rates observed for the columns fed with the river water organic matter (RWOM) and the hydrophilic fraction of the river water organic matter. These different biodegradation rates did not correlate with any of the parameters investigated in this study (cellular adenosine triphosphate (cATP), DOC removal, specific ultraviolet absorbance (SUVA), richness/evenness of the soil microbial population or OMP category (hydrophobicity/charge). Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of Animal Diet, Manure Application Rate, and Tillage on Transport of Microorganisms from Manure-Amended Fields ▿

PubMed Central

Durso, Lisa M.; Gilley, John E.; Marx, David B.; Woodbury, Bryan L.

2011-01-01

Manure from cattle fed distillers' grain or corn diets was applied to fields, and the fields were subjected to rainfall simulation tests. Manure was added at three rates on till and no-till plots. Correlations between microbial transport and runoff characteristics were identified. Results indicate that diet affects phage but not bacterial transport from manure-amended fields. PMID:21803913

Development of an Acetate- or Sugar-fed Microbial Power Generator for Military Bases

DTIC Science & Technology

2012-07-01

the U.S. military, which consumes 395,000 barrels of oil every day (Warner and Singer, 2009). Transport of fossil fuels to remote places in hostile... sOy ^ % (19%) ****** SP.(6%\\ ’ Soehngenia saccharolytica Geobocter sp. (14%) 11%) ^^ ^ Citrobacter 0</ £ -. sp...performance liquid chromatography (HPLC) equipped with BIORAD Aminex HPX-87H column for sugars and volatile acids analysis. Sucrose analysis employed water

Mixed-culture H2 fermentation performance and the relation between microbial community composition and hydraulic retention times for a fixed bed reactor fed with galactose/glucose mixtures.

PubMed

Anburajan, Parthiban; Park, Jong-Hun; Sivagurunathan, Periyasamy; Pugazhendhi, Arivalagan; Kumar, Gopalakrishnan; Choi, Chang-Su; Kim, Sang-Hyoun

2017-09-01

This study examined the mesophilic continuous biohydrogen fermentation from galactose and glucose mixture with an initial substrate concentration of 15 g/L (galactose 12 g/L and glucose 3 g/L) as a resembling carbon source of pretreated red algal hydrolyzate. A fixed bed reactor was fed with the sugar mixture at various hydraulic retention times (HRTs) ranging 12 to 1.5 h. The maximum hydrogen production rate of 52.6 L/L-d was found at 2 h HRT, while the maximum hydrogen yield of 2.3±0.1 mol/mol hexose added, was achieved at 3 h HRT. Microbial communities and species distribution were analyzed via quantitative polymerase chain reaction (qPCR) and the dominant bacterial population was found as Clostridia followed by Lactobacillus sp. Packing material retained higher 16S rRNA gene copy numbers of total bacteria and Clostridium butyricum fraction compared to fermentation liquor. The finding of the study has demonstrated that H 2 production from galactose and glucose mixture could be a viable approach for hydrogen production. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Evaluating the impacts of triclosan on wastewater treatment performance during startup and acclimation.

PubMed

Holzem, R M; Gardner, C M; Gunsch, C K

2018-01-01

Triclosan (TCS) is a broad range antimicrobial agent used in many personal care products, which is commonly discharged to wastewater treatment facilities (WWTFs). This study examined the impact of TCS on wastewater treatment performance using laboratory bench-scale sequencing batch reactors (SBRs) coupled with anaerobic digesters. The SBRs were continuously fed synthetic wastewater amended with or without 0.68 μM TCS, with the aim of determining the effect of chronic TCS exposure as opposed to a pulse TCS addition as previously studied. Overall, the present study suggests inhibition of nitrogen removal during reactor startup. However, NH 4 + removal fully rebounded after 63 days, suggesting acclimation of the associated microbial communities to TCS. An initial decrease in microbial community diversity was observed in the SBRs fed TCS as compared to the control SBRs, followed by an increase in community diversity, which coincided with the increase in NH 4 + removal. Elevated levels of NO 3 - and NO 2 - were found in the reactor effluent after day 58, however, suggesting ammonia oxidizing bacteria rebounding more rapidly than nitrogen oxidizing bacteria. Similar effects on treatment efficiencies at actual WWTFs have not been widely observed, suggesting that continuous addition of TCS in their influent may have selected for TCS-resistant nitrogen oxidizing bacteria.

Dynamic autoinoculation and the microbial ecology of a deep water hydrocarbon irruption

PubMed Central

Valentine, David L.; Mezić, Igor; Maćešić, Senka; Črnjarić-Žic, Nelida; Ivić, Stefan; Hogan, Patrick J.; Fonoberov, Vladimir A.; Loire, Sophie

2012-01-01

The irruption of gas and oil into the Gulf of Mexico during the Deepwater Horizon event fed a deep sea bacterial bloom that consumed hydrocarbons in the affected waters, formed a regional oxygen anomaly, and altered the microbiology of the region. In this work, we develop a coupled physical–metabolic model to assess the impact of mixing processes on these deep ocean bacterial communities and their capacity for hydrocarbon and oxygen use. We find that observed biodegradation patterns are well-described by exponential growth of bacteria from seed populations present at low abundance and that current oscillation and mixing processes played a critical role in distributing hydrocarbons and associated bacterial blooms within the northeast Gulf of Mexico. Mixing processes also accelerated hydrocarbon degradation through an autoinoculation effect, where water masses, in which the hydrocarbon irruption had caused blooms, later returned to the spill site with hydrocarbon-degrading bacteria persisting at elevated abundance. Interestingly, although the initial irruption of hydrocarbons fed successive blooms of different bacterial types, subsequent irruptions promoted consistency in the structure of the bacterial community. These results highlight an impact of mixing and circulation processes on biodegradation activity of bacteria during the Deepwater Horizon event and suggest an important role for mixing processes in the microbial ecology of deep ocean environments. PMID:22233808

Hydrothermal Synthesis of Nanostructured Manganese Oxide as Cathodic Catalyst in a Microbial Fuel Cell Fed with Leachate

PubMed Central

Haoran, Yuan; Lifang, Deng; Tao, Lu; Yong, Chen

2014-01-01

Much effort has been devoted to the synthesis of novel nanostructured MnO2 materials because of their unique properties and potential applications as cathode catalyst in Microbial fuel cell. Hybrid MnO2 nanostructures were fabricated by a simple hydrothermal method in this study. Their crystal structures, morphology, and electrochemical characters were carried out by FESEM, N2-adsorption-desorption, and CV, indicating that the hydrothermally synthesized MnO2 (HSM) was structured by nanorods of high aspect ratio and multivalve nanoflowers and more positive than the naturally synthesized MnO2 (NSM), accompanied by a noticeable increase in oxygen reduction peak current. When the HSM was employed as the cathode catalyst in air-cathode MFC which fed with leachate, a maximum power density of 119.07 mW/m2 was delivered, 64.68% higher than that with the NSM as cathode catalyst. Furthermore, the HSM via a 4-e pathway, but the NSM via a 2-e pathway in alkaline solution, and as 4-e pathway is a more efficient oxygen reduction reaction, the HSM was more positive than NSM. Our study provides useful information on facile preparation of cost-effective cathodic catalyst in air-cathode MFC for wastewater treatment. PMID:24723824

Oral Administration of Live Exopolysaccharide-Producing Pediococcus parvulus, but Not Purified Exopolysaccharide, Suppressed Enterobacteriaceae without Affecting Bacterial Diversity in Ceca of Mice

PubMed Central

Xu, Jie; Öste, Rickard; Holst, Olle; Molin, Göran

2013-01-01

Growing evidence indicates that the gut microbiota could have an important role in the development of diet- and lifestyle-induced diseases. It has been shown that modulation of the gut microbiota by means of probiotics and prebiotics could improve host health. An oat-based product fermented by the exopolysaccharide (EPS)-producing organism Pediococcus parvulus 2.6 has been reported to have a bifidogenic effect. To find out whether the effect could be attributed to the EPS or the bacterium, mice were fed a diet supplemented with 2% purified EPS or 108 CFU/g of live P. parvulus 2.6 for 6 weeks. Both supplementations altered the gut microbiota composition but in different directions. Purified EPS not only significantly lowered the microbial diversity (P < 0.001) but decreased the bifidobacterial population (P = 0.01). In contrast, the live EPS-producing bacterium P. parvulus 2.6 antagonized Enterobacteriaceae without disturbing the homeostasis of the cecal microbiota. PMID:23770909

Early Gut Microbiota Perturbations Following Intrapartum Antibiotic Prophylaxis to Prevent Group B Streptococcal Disease.

PubMed

Mazzola, Giuseppe; Murphy, Kiera; Ross, R Paul; Di Gioia, Diana; Biavati, Bruno; Corvaglia, Luigi T; Faldella, Giacomo; Stanton, Catherine

2016-01-01

The faecal microbiota composition of infants born to mothers receiving intrapartum antibiotic prophylaxis with ampicillin against group B Streptococcus was compared with that of control infants, at day 7 and 30 of life. Recruited newborns were both exclusive breastfed and mixed fed, in order to also study the effect of dietary factors on the microbiota composition. Massive parallel sequencing of the V3-V4 region of the 16S rRNA gene and qPCR analysis were performed. Antibiotic prophylaxis caused the most marked changes on the microbiota in breastfed infants, mainly resulting in a higher relative abundance of Enterobacteriaceae, compared with control infants (52% vs. 14%, p = 0.044) and mixed-fed infants (52% vs. 16%, p = 0.13 NS) at day 7 and in a lower bacterial diversity compared to mixed-fed infants and controls. Bifidobacteria were also particularly vulnerable and abundances were reduced in breastfed (p = 0.001) and mixed-fed antibiotic treated groups compared to non-treated groups. Reductions in bifidobacteria in antibiotic treated infants were also confirmed by qPCR. By day 30, the bifidobacterial population recovered and abundances significantly increased in both breastfed (p = 0.025) and mixed-fed (p = 0.013) antibiotic treated groups, whereas Enterobacteriaceae abundances remained highest in the breastfed antibiotic treated group (44%), compared with control infants (16%) and mixed-fed antibiotic treated group (28%). This study has therefore demonstrated the short term consequences of maternal intrapartum antibiotic prophylaxis on the infant faecal microbial population, particularly in that of breastfed infants.

Microbial fuel cells operating on mixed fatty acids.

PubMed

Freguia, Stefano; Teh, Ee Hoi; Boon, Nico; Leung, Kar Man; Keller, Jurg; Rabaey, Korneel

2010-02-01

Strategies are being developed to harvest the energy content of the wasted sludge generated from the treatment of domestic wastewater. Sludge can be hydrolysed and fermented, giving a mixture of volatile fatty acids (VFAs). Based on the composition of such a fermented stream, synthetic media were created and tested for VFA conversion in microbial fuel cells (MFCs). Mainly acetate and propionate were preferred as electron donors in the mixed VFA system, which generated a power density of 49+/-1 mW L(NAC)(-1). The other VFAs (butyrates/valerates/caproic acid) were also removed, albeit at lower rates. In single VFA tests, each VFA could be removed, but particularly i-butyrate did not provide significant current generation. PCR-DGGE indicated that the microbial community structure was highly determined by the fed VFA, rather than by the initial inoculum. The communities were dominated by Proteobacteria such as Geobacter, Comamonas, Pseudomonas and Pelobacter species. This study demonstrated the feasibility of using fatty acids, as present in fermented sludge hydrolysates, for current generation.

Evaluation of Laminaria-based microbial fuel cells (LbMs) for electricity production.

PubMed

Gadhamshetty, Venkataramana; Belanger, Derek; Gardiner, Carly-Jeanne; Cummings, Anasha; Hynes, Anne

2013-01-01

Marine algae represents a sustainable feedstock in microbial fuel cells (MFCs) due to its low water and energy requirements for cultivation, higher capacity to sequester carbondioxide, and high carbohydrate content. Two-compartment MFCs were evaluated under batch-fed mode using Laminaria saccharina as the model for algae-based electron donor, and mixed microbial consortia as the biocatalyst, in the anode compartment. The Laminaria-based MFCs (LBMs) were studied with three different pretreatment conditions for the L. saccharina: (i) autoclaving (Auto), (ii) microwave irradiation (Micro), and (iii) as received treatment (No-Treat). A control was setup to establish base line performance for two-compartment MFCs using glucose as the electron donor in the anode. The performance of LBMs (250 mW/m(2) and 900 mA/m(2)) was on par with glucose-based MFCs. AC impedance analysis revealed that the charge transfer resistance was at least 50-fold higher than the corresponding ohmic losses in both LBMs and glucose-based MFCs. Copyright © 2012 Elsevier Ltd. All rights reserved.

Analysis of Nitrification Efficiency and Microbial Community in a Membrane Bioreactor Fed with Low COD/N-Ratio Wastewater

PubMed Central

Ma, Jinxing; Wang, Zhiwei; Zhu, Chaowei; Liu, Shumeng; Wang, Qiaoying; Wu, Zhichao

2013-01-01

In this study, an approach using influent COD/N ratio reduction was employed to improve process performance and nitrification efficiency in a membrane bioreactor (MBR). Besides sludge reduction, membrane fouling alleviation was observed during 330 d operation, which was attributed to the decreased production of soluble microbial products (SMP) and efficient carbon metabolism in the autotrophic nitrifying community. 454 high-throughput 16S rRNA gene pyrosequencing revealed that the diversity of microbial sequences was mainly determined by the feed characteristics, and that microbes could derive energy by switching to a more autotrophic metabolism to resist the environmental stress. The enrichment of nitrifiers in an MBR with a low COD/N-ratio demonstrated that this condition stimulated nitrification, and that the community distribution of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) resulted in faster nitrite uptake rates. Further, ammonia oxidation was the rate-limiting step during the full nitrification. PMID:23667573

Detailed Dimethylacetal and Fatty Acid Composition of Rumen Content from Lambs Fed Lucerne or Concentrate Supplemented with Soybean Oil

PubMed Central

Alves, Susana P.; Santos-Silva, José; Cabrita, Ana R. J.; Fonseca, António J. M.; Bessa, Rui J. B.

2013-01-01

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18∶1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18∶2n−6 and 18∶3n−3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18∶0 might be produced during biohydrogenation of the 18∶3n−3. PMID:23484024

Lambs Fed Fresh Winter Forage Rape (Brassica napus L.) Emit Less Methane than Those Fed Perennial Ryegrass (Lolium perenne L.), and Possible Mechanisms behind the Difference

PubMed Central

Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J.; Luo, Dongwen; Janssen, Peter H.; Pacheco, David

2015-01-01

The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems. PMID:25803688

Phylogenetic Characterization of Fecal Microbial Communities of Dogs Fed Diets with or without Supplemental Dietary Fiber Using 454 Pyrosequencing

PubMed Central

Middelbos, Ingmar S.; Vester Boler, Brittany M.; Qu, Ani; White, Bryan A.; Swanson, Kelly S.; Fahey, George C.

2010-01-01

Background Dogs suffer from many of the same maladies as humans that may be affected by the gut microbiome, but knowledge of the canine microbiome is incomplete. This work aimed to use 16S rDNA tag pyrosequencing to phylogenetically characterize hindgut microbiome in dogs and determine how consumption of dietary fiber affects community structure. Principal Findings Six healthy adult dogs were used in a crossover design. A control diet without supplemental fiber and a beet pulp-supplemented (7.5%) diet were fed. Fecal DNA was extracted and the V3 hypervariable region of the microbial 16S rDNA gene amplified using primers suitable for 454-pyrosequencing. Microbial diversity was assessed on random 2000-sequence subsamples of individual and pooled DNA samples by diet. Our dataset comprised 77,771 reads with an average length of 141 nt. Individual samples contained approximately 129 OTU, with Fusobacteria (23 – 40% of reads), Firmicutes (14 – 28% of reads) and Bacteroidetes (31 – 34% of reads) being co-dominant phyla. Feeding dietary fiber generally decreased Fusobacteria and increased Firmicutes, but these changes were not equally apparent in all dogs. UniFrac analysis revealed that structure of the gut microbiome was affected by diet and Firmicutes appeared to play a strong role in by-diet clustering. Conclusions Our data suggest three co-dominant bacterial phyla in the canine hindgut. Furthermore, a relatively small amount of dietary fiber changed the structure of the gut microbiome detectably. Our data are among the first to characterize the healthy canine gut microbiome using pyrosequencing and provide a basis for studies focused on devising dietary interventions for microbiome-associated diseases. PMID:20339542

Identification of Electrode Respiring, Hydrocarbonoclastic Bacterial Strain Stenotrophomonas maltophilia MK2 Highlights the Untapped Potential for Environmental Bioremediation

PubMed Central

Venkidusamy, Krishnaveni; Megharaj, Mallavarapu

2016-01-01

Electrode respiring bacteria (ERB) possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS) because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential toward organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon fed MERS, showed a potent hydrocarbonoclastic behavior under aerobic and anaerobic environments. Distinct properties of the strain MK2 were anaerobic fermentation of the amino acids, electrode respiration, anaerobic nitrate reduction and the ability to metabolize n-alkane components (C8–C36) of petroleum hydrocarbons (PH) including the biomarkers, pristine and phytane. The characteristic of diazoic dye decolorization was used as a criterion for pre-screening the possible electrochemically active microbial candidates. Bioelectricity generation with concomitant dye decolorization in MERS showed that the strain is electrochemically active. In acetate fed microbial fuel cells (MFCs), maximum current density of 273 ± 8 mA/m2 (1000 Ω) was produced (power density 113 ± 7 mW/m2) by strain MK2 with a coulombic efficiency of 34.8%. Further, the presence of possible alkane hydroxylase genes (alkB and rubA) in the strain MK2 indicated that the genes involved in hydrocarbon degradation are of diverse origin. Such observations demonstrated the potential of facultative hydrocarbon degradation in contaminated environments. Identification of such a novel petrochemical hydrocarbon degrading ERB is likely to offer a new route to the sustainable bioremedial process of source zone contamination with simultaneous energy generation through MERS. PMID:28018304

Effects of Fruit Toxins on Intestinal and Microbial β-Glucosidase Activities of Seed-Predating and Seed-Dispersing Rodents (Acomys spp.).

PubMed

Kohl, Kevin D; Samuni-Blank, Michal; Lymberakis, Petros; Kurnath, Patrice; Izhaki, Ido; Arad, Zeev; Karasov, William H; Dearing, M Denise

2016-01-01

Plant secondary compounds (PSCs) have profound influence on the ecological interaction between plants and their consumers. Glycosides, a class of PSC, are inert in their intact form and become toxic on activation by either plant β-glucosidase enzymes or endogenous β-glucosidases produced by the intestine of the plant-predator or its microbiota. Many insect herbivores decrease activities of endogenous β-glucosidases to limit toxin exposure. However, such an adaptation has never been investigated in nonmodel mammals. We studied three species of spiny mice (Acomys spp.) that vary in their feeding behavior of the glycoside-rich fruit of Ochradenus baccatus. Two species, the common (Acomys cahirinus) and Crete (Acomys minous) spiny mice, behaviorally avoid activating glycosides, while the golden spiny mouse (Acomys russatus) regularly consumes activated glycosides. We fed each species a nontoxic diet of inert glycosides or a toxic diet of activated fruit toxins and investigated the responses of intestinal and microbial β-glucosidase activities. We found that individuals feeding on activated toxins had lower intestinal β-glucosidase activity and that the species that behaviorally avoid activating glycosides also had lower intestinal β-glucosidase activity regardless of treatment. The microbiota represented a larger source of toxin liberation, and the toxin-adapted species (golden spiny mouse) exhibited almost a fivefold increase in microbial β-glucosidase when fed activated toxins, while other species showed slight decreases. These results are contrary to those in insects, where glycoside-adapted species have lower β-glucosidase activity. The glycoside-adapted golden spiny mouse may have evolved tolerance mechanisms such as enhanced detoxification rather than avoidance mechanisms.

Dietary green-plant thylakoids decrease gastric emptying and gut transit, promote changes in the gut microbial flora, but does not cause steatorrhea.

PubMed

Stenblom, Eva-Lena; Weström, Björn; Linninge, Caroline; Bonn, Peter; Farrell, Mary; Rehfeld, Jens F; Montelius, Caroline

2016-01-01

Green-plant thylakoids increase satiety by affecting appetite hormones such as ghrelin, cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1). The objective of this study was to investigate if thylakoids also affect gastrointestinal (GI) passage and microbial composition. To analyse the effects on GI passage, 16 rats were gavage-fed a control or thylakoid-supplemented high-fat diet (HFD) 30 min before receiving Evans blue. Another 16 rats were fed a control HFD or thylakoid HFD for two weeks prior to the intragastric challenge with Evans blue. The amount of Evans blue in the stomach and the distance of migration in the intestines after 30 min were used as a measurement of gastric emptying and intestinal transit. These were reduced by thylakoid supplementation in the acute study, and however not significantly also after the two-week diet study. The second aim of the study was to investigate if thylakoid-supplementation affects the gut microbiota and amount of faecal fat in healthy human volunteers ( n  = 34) receiving thylakoid or placebo treatments for three months. Microbiota was analysed using 16S rRNA gene sequencing and qPCR, and faecal fat was extracted by dichloromethane. The total bacteria, and specifically the Bacteriodes fragilis group, were increased by thylakoid treatment versus placebo, while thylakoids did not cause steatorrhea. Dietary supplementation with thylakoids thus affects satiety both via appetite hormones and GI fullness, and affects the microbial composition without causing GI adverse effects such as steatorrhea. This suggests thylakoids as a novel agent in prevention and treatment of obesity.

The Effect of Dietary Supplementation with Spent Cider Yeast on the Swine Distal Gut Microbiome

PubMed Central

Upadrasta, Aditya; O’Sullivan, Lisa; O’Sullivan, Orla; Sexton, Noel; Lawlor, Peadar G.; Hill, Colin; Fitzgerald, Gerald F.; Stanton, Catherine; Ross, R. Paul

2013-01-01

Background There is an increasing need for alternatives to antibiotics for promoting animal health, given the increasing problems associated with antibiotic resistance. In this regard, we evaluated spent cider yeast as a potential probiotic for modifying the gut microbiota in weanling pigs using pyrosequencing of 16S rRNA gene libraries. Methodology and Principal Findings Piglets aged 24–26 days were assigned to one of two study groups; control (n = 12) and treatment (n = 12). The control animals were fed with a basal diet and the treatment animals were fed with basal diet in combination with cider yeast supplement (500 ml cider yeast containing ∼7.6 log CFU/ml) for 21 days. Faecal samples were collected for 16s rRNA gene compositional analysis. 16S rRNA compositional sequencing analysis of the faecal samples collected from day 0 and day 21 revealed marked differences in microbial diversity at both the phylum and genus levels between the control and treatment groups. This analysis confirmed that levels of Salmonella and Escherichia were significantly decreased in the treatment group, compared with the control (P<0.001). This data suggest a positive influence of dietary supplementation with live cider yeast on the microbial diversity of the pig distal gut. Conclusions/Significance The effect of dietary cider yeast on porcine gut microbial communities was characterized for the first time using 16S rRNA gene compositional sequencing. Dietary cider yeast can potentially alter the gut microbiota, however such changes depend on their endogenous microbiota that causes a divergence in relative response to that given diet. PMID:24130736

Short communication: Intestinal digestibility of amino acids in fluid- and particle-associated rumen bacteria determined using a precision-fed cecectomized rooster bioassay.

PubMed

Fonseca, A C; Fredin, S M; Ferraretto, L F; Parsons, C M; Utterback, P L; Shaver, R D

2014-01-01

Microbial protein represents the majority of metabolizable protein absorbed by ruminant animals. Enhanced understanding of the AA digestibility of rumen microbes will improve estimates of metabolizable protein. The objective of this experiment was to determine the digestibility of AA in fluid- (FAB) and particle-associated bacteria (PAB) using the precision-fed cecectomized rooster bioassay. Bacteria were isolated from 4 ruminally cannulated lactating Holstein cows by differential centrifugation, including particle suspension in 0.1% Tween-80 for increased removal of PAB from ruminal digesta. Samples of FAB and PAB were fed to 9 cecectomized roosters to determine standardized digestibility of AA. Total AA digestibility was 76.8 and 75.5% for FAB and PAB, respectively, but did not differ. Differences existed in AA digestibilities within bacterial type when compared with the mean essential AA digestibility value. Compared with previous literature estimates of AA digestibility in microbes (mean = 76%; range = 57-87%) and relative to National Research Council estimates of total AA from rumen bacteria (80%), the precision-fed cecectomized rooster assay is an acceptable in vivo model to determine AA digestibility of rumen bacteria. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Continuous Cellulosic Bioethanol Fermentation by Cyclic Fed-Batch Cocultivation

PubMed Central

Jiang, He-Long; He, Qiang; He, Zhili; Hemme, Christopher L.; Wu, Liyou

2013-01-01

Cocultivation of cellulolytic and saccharolytic microbial populations is a promising strategy to improve bioethanol production from the fermentation of recalcitrant cellulosic materials. Earlier studies have demonstrated the effectiveness of cocultivation in enhancing ethanolic fermentation of cellulose in batch fermentation. To further enhance process efficiency, a semicontinuous cyclic fed-batch fermentor configuration was evaluated for its potential in enhancing the efficiency of cellulose fermentation using cocultivation. Cocultures of cellulolytic Clostridium thermocellum LQRI and saccharolytic Thermoanaerobacter pseudethanolicus strain X514 were tested in the semicontinuous fermentor as a model system. Initial cellulose concentration and pH were identified as the key process parameters controlling cellulose fermentation performance in the fixed-volume cyclic fed-batch coculture system. At an initial cellulose concentration of 40 g liter−1, the concentration of ethanol produced with pH control was 4.5-fold higher than that without pH control. It was also found that efficient cellulosic bioethanol production by cocultivation was sustained in the semicontinuous configuration, with bioethanol production reaching 474 mM in 96 h with an initial cellulose concentration of 80 g liter−1 and pH controlled at 6.5 to 6.8. These results suggested the advantages of the cyclic fed-batch process for cellulosic bioethanol fermentation by the cocultures. PMID:23275517

Enriching acid rock drainage related microbial communities from surface-deposited oil sands tailings.

PubMed

Dean, Courtney; Xiao, Yeyuan; Roberts, Deborah J

2016-10-01

Little is known about the microbial communities native to surface-deposited pyritic oil sands tailings, an environment where acid rock drainage (ARD) could occur. The goal of this study was to enrich sulfur-oxidizing organisms from these tailings and determine whether different populations exist at pH levels 7, 4.5, and 2.5. Using growth-based methods provides model organisms for use in the future to predict potential activities and limitations of these organisms and to develop possible control methods. Thiosulfate-fed enrichment cultures were monitored for approximately 1 year. The results showed that the enrichments at pH 4.5 and 7 were established quicker than at pH 2.5. Different microbial community structures were found among the 3 pH environments. The sulfur-oxidizing microorganisms identified were most closely related to Halothiobacillus neapolitanus, Achromobacter spp., and Curtobacterium spp. While microorganisms related to Chitinophagaceae and Acidocella spp. were identified as the only possible iron-oxidizing and -reducing microbes. These results contribute to the general knowledge of the relatively understudied microbial communities that exist in pyritic oil sands tailings and indicate these communities may have a potential role in ARD generation, which may have implications for future tailings management.

Biorefining of by-product streams from sunflower-based biodiesel production plants for integrated synthesis of microbial oil and value-added co-products.

PubMed

Leiva-Candia, D E; Tsakona, S; Kopsahelis, N; García, I L; Papanikolaou, S; Dorado, M P; Koutinas, A A

2015-08-01

This study focuses on the valorisation of crude glycerol and sunflower meal (SFM) from conventional biodiesel production plants for the separation of value-added co-products (antioxidant-rich extracts and protein isolate) and for enhancing biodiesel production through microbial oil synthesis. Microbial oil production was evaluated using three oleaginous yeast strains (Rhodosporidium toruloides, Lipomyces starkeyi and Cryptococcus curvatus) cultivated on crude glycerol and nutrient-rich hydrolysates derived from either whole SFM or SFM fractions that remained after separation of value-added co-products. Fed-batch bioreactor cultures with R. toruloides led to the production of 37.4gL(-1) of total dry weight with a microbial oil content of 51.3% (ww(-1)) when a biorefinery concept based on SFM fractionation was employed. The estimated biodiesel properties conformed with the limits set by the EN 14214 and ASTM D 6751 standards. The estimated cold filter plugging point (7.3-8.6°C) of the lipids produced by R. toruloides is closer to that of biodiesel derived from palm oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acetate enhances startup of a H₂-producing microbial biocathode.

PubMed

Jeremiasse, Adriaan W; Hamelers, Hubertus V M; Croese, Elsemiek; Buisman, Cees J N

2012-03-01

H(2) can be produced from organic matter with a microbial electrolysis cell (MEC). To decrease MEC capital costs, a cathode is needed that is made of low-cost material and produces H(2) at high rate. A microbial biocathode is a low-cost candidate, but suffers from a long startup and a low H(2) production rate. In this study, the effects of cathode potential and carbon source on microbial biocathode startup were investigated. Application of a more negative cathode potential did not decrease the startup time of the biocathode. If acetate instead of bicarbonate was used as carbon source, the biocathode started up more than two times faster. The faster startup was likely caused by a higher biomass yield for acetate than for bicarbonate, which was supported by thermodynamic calculations. To increase the H(2) production rate, a flow through biocathode fed with acetate was investigated. This biocathode produced 2.2 m(3) H(2) m(-3)  reactor day(-1) at a cathode potential of -0.7 V versus NHE, which was seven times that of a parallel flow biocathode of a previous study. Copyright © 2011 Wiley Periodicals, Inc.

Segregation of the Anodic Microbial Communities in a Microbial Fuel Cell Cascade

PubMed Central

Hodgson, Douglas M.; Smith, Ann; Dahale, Sonal; Stratford, James P.; Li, Jia V.; Grüning, André; Bushell, Michael E.; Marchesi, Julian R.; Avignone Rossa, C.

2016-01-01

Metabolic interactions within microbial communities are essential for the efficient degradation of complex organic compounds, and underpin natural phenomena driven by microorganisms, such as the recycling of carbon-, nitrogen-, and sulfur-containing molecules. These metabolic interactions ultimately determine the function, activity and stability of the community, and therefore their understanding would be essential to steer processes where microbial communities are involved. This is exploited in the design of microbial fuel cells (MFCs), bioelectrochemical devices that convert the chemical energy present in substrates into electrical energy through the metabolic activity of microorganisms, either single species or communities. In this work, we analyzed the evolution of the microbial community structure in a cascade of MFCs inoculated with an anaerobic microbial community and continuously fed with a complex medium. The analysis of the composition of the anodic communities revealed the establishment of different communities in the anodes of the hydraulically connected MFCs, with a decrease in the abundance of fermentative taxa and a concurrent increase in respiratory taxa along the cascade. The analysis of the metabolites in the anodic suspension showed a metabolic shift between the first and last MFC, confirming the segregation of the anodic communities. Those results suggest a metabolic interaction mechanism between the predominant fermentative bacteria at the first stages of the cascade and the anaerobic respiratory electrogenic population in the latter stages, which is reflected in the observed increase in power output. We show that our experimental system represents an ideal platform for optimization of processes where the degradation of complex substrates is involved, as well as a potential tool for the study of metabolic interactions in complex microbial communities. PMID:27242723

The relationship between odd- and branched-chain fatty acids and microbial nucleic acid bases in rumen

PubMed Central

Liu, Keyuan; Hao, Xiaoyan; Li, Yang; Luo, Guobin; Zhang, Yonggen; Xin, Hangshu

2017-01-01

Objective This study aims to identify the relationship between odd- and branched-chain fatty acids (OBCFAs) and microbial nucleic acid bases in the rumen, and to establish a model to accurately predict microbial protein flow by using OBCFA. Methods To develop the regression equations, data on the rumen contents of individual cows were obtained from 2 feeding experiments. In the first experiment, 3 rumen-fistulated dry dairy cows arranged in a 3×3 Latin square were fed diets of differing forage to concentration ratios (F:C). The second experiment consisted of 9 lactating Holstein dairy cows of similar body weights at the same stage of pregnancy. For each lactation stage, 3 cows with similar milk production were selected. The rumen contents were sampled at 4 time points of every two hours after morning feeding 6 h, and then to analyse the concentrations of OBCFA and microbial nucleic acid bases in the rumen samples. Results The ruminal bacteria nucleic acid bases were significantly influenced by feeding diets of differing forge to concentration ratios and lactation stages of dairy cows (p<0.05). The concentrations of OBCFAs, especially odd-chain fatty acids and C15:0 isomers, strongly correlated with the microbial nucleic acid bases in the rumen (p<0.05). The equations of ruminal microbial nucleic acid bases established by ruminal OBCFAs contents showed a good predictive capacity, as indicated by reasonably low standard errors and high R-squared values. Conclusion This finding suggests that the rumen OBCFA composition could be used as an internal marker of rumen microbial matter. PMID:28728386

The relationship between odd- and branched-chain fatty acids and microbial nucleic acid bases in rumen.

PubMed

Liu, Keyuan; Hao, Xiaoyan; Li, Yang; Luo, Guobin; Zhang, Yonggen; Xin, Hangshu

2017-11-01

This study aims to identify the relationship between odd- and branched-chain fatty acids (OBCFAs) and microbial nucleic acid bases in the rumen, and to establish a model to accurately predict microbial protein flow by using OBCFA. To develop the regression equations, data on the rumen contents of individual cows were obtained from 2 feeding experiments. In the first experiment, 3 rumen-fistulated dry dairy cows arranged in a 3×3 Latin square were fed diets of differing forage to concentration ratios (F:C). The second experiment consisted of 9 lactating Holstein dairy cows of similar body weights at the same stage of pregnancy. For each lactation stage, 3 cows with similar milk production were selected. The rumen contents were sampled at 4 time points of every two hours after morning feeding 6 h, and then to analyse the concentrations of OBCFA and microbial nucleic acid bases in the rumen samples. The ruminal bacteria nucleic acid bases were significantly influenced by feeding diets of differing forge to concentration ratios and lactation stages of dairy cows (p<0.05). The concentrations of OBCFAs, especially odd-chain fatty acids and C15:0 isomers, strongly correlated with the microbial nucleic acid bases in the rumen (p<0.05). The equations of ruminal microbial nucleic acid bases established by ruminal OBCFAs contents showed a good predictive capacity, as indicated by reasonably low standard errors and high R-squared values. This finding suggests that the rumen OBCFA composition could be used as an internal marker of rumen microbial matter.

Effects of exogenous enzymes in corn-based and Canadian pearl millet-based diets with reduced soybean meal on growth performance, intestinal nutrient digestibility, villus development, and selected microbial populations in broiler chickens.

PubMed

Baurhoo, N; Baurhoo, B; Zhao, X

2011-12-01

An experiment was conducted to compare a commercial corn-soybean meal diet with a pearl millet diet containing less soybean meal (-27%), alone or in combination with exogenous enzymes, on growth performance, jejunal villus development, ileal CP, and AA digestibility, and cecal microbial populations in broilers. One hundred sixty 1-d-old male Ross 508 broilers (5/cage) were randomly allocated to one of the following dietary treatments: 1) a standard corn-soybean meal control diet (CTL); 2) a pearl millet-soybean meal diet (PM); 3) CTL + exogenous enzymes (CE); and 4) PM + exogenous enzymes (PE) with 8 replicate cages/treatment. The PM and PE diets contained less soybean meal because of greater CP and AA contents of pearl millet. All diets were isonitrogenous and isocaloric. Body weight and feed intake were recorded weekly over 35 d. At d 21 and 35, 8 broilers per treatment were euthanized for sample collection and analyses. Gain-to-feed was greater (P < 0.01) for pearl millet- than corn-based diets. Apparent ileal digestibility (AID) of CP and most AA was similar between corn-based and pearl millet-based diets, and enzyme supplementation improved AID of CP (P < 0.01) and most AA at both d 21 and 35. However, for AID of some AA at d 21, the response to enzyme supplementation was less pronounced in broilers fed pearl millet-based diets than those fed corn-based diets (grain × enzyme, P ≤ 0.05). The villus was longer (P < 0.01) in broilers fed PM and PE than CTL and CE at d 35. Similarly, at d 35, lactobacilli loads were greater (P < 0.01) in broilers fed PM and PE than CTL and CE. It is concluded that, in comparison with corn, broiler diets formulated with pearl millet require less soybean meal and can be used to improve growth performance traits, intestinal lactobacilli populations, and villus development, whereas enzyme supplementation increases AID of CP and AA.

Effects of microbial phytase, produced by solid-state fermentation, on the performance and nutrient utilisation of broilers fed maize- and wheat-based diets.

PubMed

Wu, Y B; Ravindran, V; Hendriks, W H

2003-12-01

1. The influence of a microbial phytase on the performance, toe ash contents and nutrient utilisation of male broilers fed diets based on maize and wheat was investigated. The experiment was conducted as 2 x 2 x 2 factorial arrangement of treatments. Within the factorial, two diet types (maize-soy or wheat-soy) containing two levels of non-phytate phosphorus (3.0 or 4.5 g/kg) were evaluated and each level of non-phytate phosphorus was supplemented with 0 or 500 PU phytase/kg diet. Each of the 8 dietary treatments were fed to 6 pens of 8 birds from d 1 to 21 post-hatching. 2. Main effects of diet type and phytase were observed for all parameters. Main effect of non-phytate phosphorus was significant only for feed/gain and toe ash contents. Phytase addition improved weight gains irrespective of diet type or non-phytate phosphorus level, but the magnitude of improvement in the phosphorus-deficient wheat-soy diet was greater, resulting in a diet type x non-phytate phosphorus interaction. Responses in toe ash contents were noted only in phosphorus-deficient diets, as indicated by a non-phytate phosphorus x phytase interaction. 3. Phytase addition improved apparent metabolisable energy values of wheat-based diets, but had little effect on the apparent metabolisable energy of maize-based diets as shown by a diet type x phytase interaction. The apparent metabolisable energy was not influenced by dietary non-phytate P. 4. Phytase improved ileal nitrogen digestibility in both diet types, but the responses to added phytase tended to be higher in wheat-based diets, as shown by a diet type x phytase interaction. 5. Increasing the dietary non-phytate phosphorus level reduced phosphorus digestibility and increased excreta phosphorus content. Addition of phytase improved phosphorus digestibility, but the increments were higher in low phosphorus diets resulting in a non-phytate phosphorus x phytase interaction. Phytase addition tended to lower the excreta phosphorus content, but the effects were greater in birds fed low phosphorus diets, as shown by a non-phytate phosphorus x phytase interaction.

Early Postnatal Diets Affect the Bioregional Small Intestine Microbiome and Ileal Metabolome in Neonatal Pigs.

PubMed

Piccolo, Brian D; Mercer, Kelly E; Bhattacharyya, Sudeepa; Bowlin, Anne K; Saraf, Manish K; Pack, Lindsay; Chintapalli, Sree V; Shankar, Kartik; Adams, Sean H; Badger, Thomas M; Yeruva, Laxmi

2017-08-01

Background: Breastfeeding is known to be protective against gastrointestinal disorders and may modify gut development. Although the gut microbiome has been implicated, little is known about how early diet affects the small intestine microbiome. Objective: We hypothesized that disparate early diets would promote unique microbial profiles in the small intestines of neonatal pigs. Methods: Male and female 2-d-old White Dutch Landrace pigs were either sow fed or provided dairy (Similac Advance powder; Ross Products Abbott Laboratories) or soy (Enfamil Prosobee Lipil powder; Mead Johnson Nutritionals) infant formulas until day 21. Bacterial ecology was assessed in the contents of the small intestine through the use of 16S ribosomal RNA sequencing. α-Diversity, β-diversity, and differential abundances of operational taxonomic units were assessed by ANOVA, permutational ANOVA, and negative binomial regression, respectively. Ileum tissue metabolomics were measured by LC-mass spectrometry and assessed by weighted correlation network analysis. Results: Greater α-diversity was observed in the duodena of sow-fed compared with formula-fed neonatal pigs ( P < 0.05). No differences were observed in the ilea. Firmicutes represented the most abundant phylum across all diets in duodena (78.8%, 80.1%, and 53.4% relative abundance in sow, dairy, and soy groups, respectively), followed by Proteobacteria in sow (12.2%) and dairy (12.4%) groups and Cyanobacteria in soy-fed (36.2%) pigs. In contrast to those in the duodenum, Proteobacteria was the dominant phylum in the ileum, with >60% relative abundance in all of the groups. In the duodenum, 77 genera were altered by diet, followed by 48 in the jejunum and 19 in the ileum. Metabolomics analyses revealed associations between ileum tissue metabolites (e.g., acylcarnitines, 3-aminoisobutyric acid) and diet-responsive microbial genera. Conclusions: These results indicate that the neonatal diet has regional effects on the small intestine microbiome in pigs, with the most pronounced effects occurring in the duodena. Regional effects may be important factors when considering gut tissue metabolism and development in the postnatal period. © 2017 American Society for Nutrition.

Post-Weaning Diet Affects Faecal Microbial Composition but Not Selected Adipose Gene Expression in the Cat (Felis catus)

PubMed Central

Bermingham, Emma N.; Kittelmann, Sandra; Young, Wayne; Kerr, Katherine R.; Swanson, Kelly S.; Roy, Nicole C.; Thomas, David G.

2013-01-01

The effects of pre- (i.e., gestation and during lactation) and post-weaning diet on the composition of faecal bacterial communities and adipose expression of key genes in the glucose and insulin pathways were investigated in the cat. Queens were maintained on a moderate protein:fat:carbohydrate kibbled (“Diet A”; 35:20:28% DM; n  =  4) or high protein:fat:carbohydrate canned (“Diet B”; 45:37:2% DM; n = 3) diet throughout pregnancy and lactation. Offspring were weaned onto these diets in a nested design (n  =  5 per treatment). Faecal samples were collected at wk 8 and 17 of age. DNA was isolated from faeces and bacterial 16S rRNA gene amplicons were analysed by pyrosequencing. RNA was extracted from blood (wk 18) and adipose tissue and ovarian/testicular tissues (wk 24) and gene expression levels determined using RT-qPCR. Differences (P<0.05) in composition of faecal bacteria were observed between pregnant queens fed Diet A or B. However, pre-weaning diet had little effect on faecal bacterial composition in weaned kittens. In contrast, post-weaning diet altered bacterial population profiles in the kittens. Increased (P<0.05) abundance of Firmicutes (77% vs 52% of total reads) and Actinobacteria (0.8% vs 0.2% of total reads), and decreased (P<0.05) abundance of Fusobacteria (1.6% vs 18.4% of total reads) were observed for kittens fed the Diet A compared to those fed Diet B post-weaning. Feeding Diet B pre-weaning increased (P<0.05) the expression levels of INRS, LEPT, PAI-1 and tended to increase GLUT1, while the expression levels of IRS-1 in blood increased in kittens fed Diet A pre-weaning. Post-weaning diet had no effect on expression levels of target genes. Correlations between the expression levels of genes involved in glucose and insulin pathways and faecal Bacteriodetes and Firmicutes phyla were identified. The reasons for why post-weaning diet affects microbial populations and not gene expression levels are of interest. PMID:24312255

Impact of narasin on manure composition and microbial ecology, and gas emissions from finishing pigs fed either a corn-soybean meal or a corn-soybean meal-dried distillers grains with solubles diets

USDA-ARS?s Scientific Manuscript database

An experiment was conducted to determine the effect of feeding finishing pigs either a corn-soybean (CSBM) diet or a CSBM diet supplemented with 30.34% distillers dried grains with solubles (DDGS), in combination with either 0 or 30 mg narasin/kg of diet, on subsequent manure composition, manure mic...

Evaluation of the bacterial diversity in the rumen and feces of cattle fed different diets containing levels of dried distillers grains plus solubles using bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP)

USDA-ARS?s Scientific Manuscript database

Dietary components and changes cause shifts in the intestinal ecology of the gut, which can play a role in animal health and productivity. However, most information about the microbial populations in the gut of livestock species has not been quantitative. In the present study, we utilized a new m...

Characterization of a Methanogenic Community within an Algal Fed Anaerobic Digester

PubMed Central

Ellis, Joshua T.; Tramp, Cody; Sims, Ronald C.; Miller, Charles D.

2012-01-01

The microbial diversity and metabolic potential of a methanogenic consortium residing in a 3785-liter anaerobic digester, fed with wastewater algae, was analyzed using 454 pyrosequencing technology. DNA was extracted from anaerobic sludge material and used in metagenomic analysis through PCR amplification of the methyl-coenzyme M reductase α subunit (mcrA) gene using primer sets ML, MCR, and ME. The majority of annotated mcrA sequences were assigned taxonomically to the genera Methanosaeta in the order Methanosarcinales. Methanogens from the genus Methanosaeta are obligate acetotrophs, suggesting this genus plays a dominant role in methane production from the analyzed fermentation sample. Numerous analyzed sequences within the algae fed anaerobic digester were unclassified and could not be assigned taxonomically. Relative amplicon frequencies were determined for each primer set to determine the utility of each in pyrosequencing. Primer sets ML and MCR performed better quantitatively (representing the large majority of analyzed sequences) than primer set ME. However, each of these primer sets was shown to provide a quantitatively unique community structure, and thus they are of equal importance in mcrA metagenomic analysis. PMID:23724331

76 FR 10226 - Airworthiness Directives; The Boeing Company Model 757 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... contents of the proposed rule. Request To Revise the Compliance Time FedEx, US Airways, Delta, European Air Transport Leipzig GmbH (European Air)/DHL Air requested a change in the compliance time. FedEx, Delta, and..., dated July 16, 2007. FedEx and Delta stated that fuel tank access occurs at 72-month intervals. European...

Vapor-fed bio-hybrid fuel cell.

PubMed

Benyamin, Marcus S; Jahnke, Justin P; Mackie, David M

2017-01-01

Concentration and purification of ethanol and other biofuels from fermentations are energy-intensive processes, with amplified costs at smaller scales. To circumvent the need for these processes, and to potentially reduce transportation costs as well, we have previously investigated bio-hybrid fuel cells (FCs), in which a fermentation and FC are closely coupled. However, long-term operation requires strictly preventing the fermentation and FC from harming each other. We introduce here the concept of the vapor-fed bio-hybrid FC as a means of continuously extracting power from ongoing fermentations at ambient conditions. By bubbling a carrier gas (N 2 ) through a yeast fermentation and then through a direct ethanol FC, we protect the FC anode from the catalyst poisons in the fermentation (which are non-volatile), and also protect the yeast from harmful FC products (notably acetic acid) and from build-up of ethanol. Since vapor-fed direct ethanol FCs at ambient conditions have never been systematically characterized (in contrast to vapor-fed direct methanol FCs), we first assess the effects on output power and conversion efficiency of ethanol concentration, vapor flow rate, and FC voltage. The results fit a continuous stirred-tank reactor model. Over a wide range of ethanol partial pressures (2-8 mmHg), power densities are comparable to those for liquid-fed direct ethanol FCs at the same temperature, with power densities >2 mW/cm 2 obtained. We then demonstrate the continuous operation of a vapor-fed bio-hybrid FC with fermentation for 5 months, with no indication of performance degradation due to poisoning (of either the FC or the fermentation). It is further shown that the system is stable, recovering quickly from disturbances or from interruptions in maintenance. The vapor-fed bio-hybrid FC enables extraction of power from dilute bio-ethanol streams without costly concentration and purification steps. The concept should be scalable to both large and small operations and should be generalizable to other biofuels and waste-to-energy systems.

Nutrient Distribution and Absorption in the Colonial Hydroid Podocoryna carnea Is Sequentially Diffusive and Directional.

PubMed

Buss, Leo W; Anderson, Christopher P; Perry, Elena K; Buss, Evan D; Bolton, Edward W

2015-01-01

The distribution and absorption of ingested protein was characterized within a colony of Podocoryna carnea when a single polyp was fed. Observations were conducted at multiple spatial and temporal scales at three different stages of colony ontogeny with an artificial food item containing Texas Red conjugated albumin. Food pellets were digested and all tracer absorbed by digestive cells within the first 2-3 hours post-feeding. The preponderance of the label was located in the fed polyp and in a transport-induced diffusion pattern surrounding the fed polyp. After 6 hours post-feeding particulates re-appeared in the gastrovascular system and their absorption increased the area over which the nutrients were distributed, albeit still in a pattern that was centered on the fed polyp. At later intervals, tracer became concentrated in some stolon tips, but not in others, despite the proximity of these stolons either to the fed polyp or to adjacent stolons receiving nutrients. Distribution and absorption of nutrients is sequentially diffusive and directional.

Microbial competition between Bacillus subtilis and Staphylococcus aureus monitored by imaging mass spectrometry

PubMed Central

Gonzalez, David J.; Haste, Nina M.; Hollands, Andrew; Fleming, Tinya C.; Hamby, Matthew; Pogliano, Kit; Nizet, Victor

2011-01-01

Microbial competition exists in the general environment, such as soil or aquatic habitats, upon or within unicellular or multicellular eukaryotic life forms. The molecular actions that govern microbial competition, leading to niche establishment and microbial monopolization, remain undetermined. The emerging technology of imaging mass spectrometry (IMS) enabled the observation that there is directionality in the metabolic output of the organism Bacillus subtilis when co-cultured with Staphylococcus aureus. The directionally released antibiotic alters S. aureus virulence factor production and colonization. Therefore, IMS provides insight into the largely hidden nature of competitive microbial encounters and niche establishment, and provides a paradigm for future antibiotic discovery. PMID:21719540

Effects of dietary protein levels and 2-methylbutyrate on ruminal fermentation, nutrient degradability, bacterial populations and urinary purine derivatives in Simmental steers.

PubMed

Wang, C; Liu, Q; Guo, G; Huo, W J; Pei, C X; Zhang, S L; Yang, W Z

2018-06-01

The objective of this study was to evaluate the effects of dietary crude protein (CP) levels and 2-methylbutyrate (MB) supplementation on ruminal fermentation, bacterial populations, microbial enzyme activity and urinary excretion of purine derivatives (PD) in Simmental steers. Eight ruminally cannulated Simmental steers, averaging 18 months of age and 465 ± 8.6 kg of body weight (BW), were used in a replicated 4 × 4 Latin square design by a 2 × 2 factorial arrangement. Low protein (98.5 g CP/kg dry matter [LP] or high protein (128.7 g CP/kg dry matter [HP]) diets were fed with MB supplementation (0 g [MB-] or 16.8 g steer -1  day -1 [MB+]). Steers were fed a total mixed ration with dietary corn straw to concentrate ratio of 50:50 (dry matter [DM] basis). The CP × MB interaction was observed for ruminal total VFA, molar proportions of acetate and propionate, acetate to propionate ratio, ammonia-N, effective degradability of neutral detergent fibre (NDF) and CP, microbial enzyme activity, bacterial populations and total PD excretion (p < .05). Ruminal pH decreased (p < .05), but ruminal total VFA concentration increased (p < .05) with increasing dietary CP level or MB supplementation. Acetate molar proportion increased (p = .043) with MB supplementation, but was not affected by dietary CP level. Propionate molar proportion decreased (p < .05) with increasing dietary CP level or MB supplementation. Consequently, acetate-to-propionate ratio increased (p = .001) with MB supplementation, but was not affected by dietary CP level. Ruminal ammonia-N content increased (p = .034) with increasing dietary CP level, but decreased (p = .012) with MB supplementation. The effective degradability of NDF and CP increased (p < .05) with increasing dietary CP level or MB supplementation. Microbial enzyme activity, bacterial populations and total PD excretion also increased (p < .05) with increasing dietary CP level or MB supplementation. The results indicated that ruminal fermentation, nutrient degradability, microbial enzyme activity, ruminal bacterial populations and microbial protein synthesis improved with increasing dietary CP level or MB supplementation in steers. © 2017 Blackwell Verlag GmbH.

Effects of graded levels of microbial phytase on apparent total tract digestibility of calcium and phosphorus and standardized total tract digestibility of phosphorus in four sources of canola meal and in soybean meal fed to growing pigs.

PubMed

She, Y; Liu, Y; Stein, H H

2017-05-01

One hundred twenty pigs were used to determine effects of graded levels of microbial phytase on the apparent total tract digestibility (ATTD) of P and Ca and the standardized total tract digestibility (STTD) of P in 4 sources of canola meal and in 1 source of soybean meal (SBM) fed to growing pigs. The 4 sources of canola meal were produced from 1 source of high-protein canola seeds and 2 sources of conventional canola seeds with 1 of the conventional canola seeds being divided into 2 separate batches before crushing. Pigs (16.2 ± 5.3 kg initial BW) were individually housed in metabolism crates and were randomly allotted to 1 of 20 diets in a 5 × 4 factorial arrangement of treatments with 5 ingredients and 4 levels of phytase. There were 6 replicate pigs per diet. Five basal diets based on high-protein canola meal (CM-HP), high-temperature processed canola meal (CM-HT), low-temperature processed canola meal (CM-LT), conventional canola meal (CM-CV), or SBM were formulated. The basal diets contained no phytase. Fifteen additional diets were prepared by adding approximately 500, 1,500, or 2,500 phytase units/kg to each of the 5 basal diets. Feces were quantitatively collected for 5 d based on the marker-to-marker approach after a 7-d adaptation period. Results indicated that supplementation of microbial phytase increased (linear, < 0.05) the ATTD of Ca in diets containing CM-HP, CM-HT, CM-CV, and SBM but not in diets containing CM-LT. Microbial phytase also increased (linear and quadratic, < 0.05) the ATTD and STTD of P in all 5 ingredients. Compared with the CM-CV diets, the CM-HP diets had greater ( < 0.05) ATTD of Ca. The ATTD of Ca in the SBM diet was greater ( < 0.05) than in all canola meal diets, but no differences were observed in ATTD of Ca between CM-HT and CM-LT diets. The ATTD and the STTD of P were less ( < 0.05) in CM-HP, CM-HT, CM-LT, or CM-CV than in SBM if no microbial phytase was added, but no differences were observed in the ATTD and STTD of P in SBM, CM-HP, CM-HT, or CM-CV if the highest amount of phytase were added (interaction, < 0.05). Regression equations were developed to calculate the response to microbial phytase on the STTD of P in CM-HP, CM-HT, CM-LT, CM-CV, and SBM. In conclusion, inclusion of graded levels of microbial phytase increased the ATTD and STTD of P in CM-HP, CM-HT, CM-LT, CM-CV, and SBM and the response to microbial phytase added to each ingredient can be predicted by regression equations.

Effects of the Dietary Protein and Carbohydrate Ratio on Gut Microbiomes in Dogs of Different Body Conditions.

PubMed

Li, Qinghong; Lauber, Christian L; Czarnecki-Maulden, Gail; Pan, Yuanlong; Hannah, Steven S

2017-01-24

Obesity has become a health epidemic in both humans and pets. A dysbiotic gut microbiota has been associated with obesity and other metabolic disorders. High-protein, low-carbohydrate (HPLC) diets have been recommended for body weight loss, but little is known about their effects on the canine gut microbiome. Sixty-three obese and lean Labrador retrievers and Beagles (mean age, 5.72 years) were fed a common baseline diet for 4 weeks in phase 1, followed by 4 weeks of a treatment diet, specifically, the HPLC diet (49.4% protein, 10.9% carbohydrate) or a low-protein, high-carbohydrate (LPHC) diet (25.5% protein, 38.8% carbohydrate) in phase 2. 16S rRNA gene profiling revealed that dietary protein and carbohydrate ratios have significant impacts on gut microbial compositions. This effect appeared to be more evident in obese dogs than in lean dogs but was independent of breed. Consumption of either diet increased the bacterial evenness, but not the richness, of the gut compared to that after consumption of the baseline diet. Macronutrient composition affected taxon abundances, mainly within the predominant phyla, Firmicutes and Bacteroidetes The LPHC diet appeared to favor the growth of Bacteroides uniformis and Clostridium butyricum, while the HPLC diet increased the abundances of Clostridium hiranonis, Clostridium perfringens, and Ruminococcus gnavus and enriched microbial gene networks associated with weight maintenance. In addition, we observed a decrease in the Bacteroidetes to Firmicutes ratio and an increase in the Bacteroides to Prevotella ratio in the HPLC diet-fed dogs compared to these ratios in dogs fed other diets. Finally, analysis of the effect of diet on the predicted microbial gene network was performed using phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt). More than 50% of dogs are either overweight or obese in the United States. A dysbiotic gut microbiota is associated with obesity and other metabolic problems in humans. HPLC diets have been promoted as an effective weight loss strategy for many years, and potential effects were reported for both humans and dogs. In this study, we explored the influence of the protein and carbohydrate ratio on the gut microbiome in dogs with different body conditions. We demonstrated significant dietary effects on the gut microbiome, with greater changes in obese dogs than in lean dogs. The HPLC diet-fed dogs showed greater abundances of Firmicutes but fewer numbers of Bacteroidetes than other dogs. This knowledge will enable us to use prebiotics, probiotics, and other nutritional interventions to modulate the gut microbiota and to provide an alternative therapy for canine obesity. Copyright © 2017 Li et al.

Recycling of treated domestic effluent from an on-site wastewater treatment system for hydroponics.

PubMed

Oyama, N; Nair, J; Ho, G E

2005-01-01

An alternative method to conserve water and produce crops in arid regions is through hydroponics. Application of treated wastewater for hydroponics will help in stripping off nutrients from wastewater, maximising reuse through reduced evaporation losses, increasing control on quality of water and reducing risk of pathogen contamination. This study focuses on the efficiency of treated wastewater from an on-site aerobic wastewater treatment unit. The experiment aimed to investigate 1) nutrient reduction 2) microbial reduction and 3) growth rate of plants fed on wastewater compared to a commercial hydroponics medium. The study revealed that the chemical and microbial quality of wastewater after hydroponics was safe and satisfactory for irrigation and plant growth rate in wastewater hydroponics was similar to those grown in a commercial medium.

Diversity of microbes and potential exoelectrogenic bacteria on anode surface in microbial fuel cells.

PubMed

Sun, Yujiao; Zuo, Jiane; Cui, Longtao; Deng, Qian; Dang, Yan

2010-02-01

Single-chamber microbial fuel cells (MFCs), inoculated with anaerobic sludge and continuously run with two kinds of organic wastewater influents, were systemically investigated. The diversity of microbes, determined by 16S rDNA analysis, was analyzed on three anodes under different conditions. One anode was in a closed circuit in synthetic wastewater containing glucose. The other two anodes, in open or closed circuits, were fed effluent from an anaerobic reactor treating starch wastewater. The chemical oxygen demand (COD) removal efficiency was about 70%, and the exported voltages were about 450 mV. The 16S rDNA molecular clones of microbes on anode surfaces showed significant changes in Eubacterial structure under different conditions. gamma-Proteobacteria and the high G+C gram-positive groups were predominant in the synthetic wastewater, while epsilon-Proteobacteria predominated in the anaerobic reactor effluent. Known exoelectrogenic bacterial species composition also changed greatly depending on substrate. On the artificial substrate, 28% of the bacterial sequences were affiliated with Aeromonas, Pseudomonas, Geobacter, and Desulfobulbus. On the anaerobic effluent, only 6% were affiliated with Geobacter or Clostridium. Because only a few exoelectrogenic bacteria from MFCs have been directly isolated and studied, we compared the community structures of two bacterial anodes, in open and closed circuits, under the same substrate of anaerobic effluent in order to identify additional exoelectrogenic bacterial strains. Alcaligenes monasteriensis, Comamonas denitrificans, and Dechloromonas sp. were found to be potential exoelectrogenic bacteria worthy of further research.

Lunar and Planetary Science XXXV: Astrobiology: Analogs and Applications to the Search for Life

NASA Technical Reports Server (NTRS)

2004-01-01

The session "Astrobiology: Analogs and Applications to the Search for Life" included the folowing reports:The Search for Life on Mars Using Macroscopically Visible Microbial Mats (Stromatolites) in 3.5/3.3 Ga Cherts from the Pilbara in Australia and Barberton in South Africa as Analogues; Life in a Mars Analog: Microbial Activity Associated with Carbonate Cemented Lava Breccias from NW Spitsbergen; Groundwater-fed Iron-rich Microbial Mats in a Freshwater Creek: Growth Cycles and Fossilization Potential of Microbial Features; Episodic Fossilization of Microorganisms on an Annual Timescale in an Anthropogenically Modified Natural Environment: Geochemical Controls and Implications for Astrobiology; Proterozoic Microfossils and Their Implications for Recognizing Life on Mars; Microbial Alteration of Volcanic Glass in Modern and Ancient Oceanic Crust as a Proxy for Studies of Extraterrestrial Material ; Olivine Alteration on Earth and Mars; Searching for an Acidic Aquifer in the R!o Tinto Basin. First Geobiology Results of MARTE Project; In-Field Testing of Life Detection Instruments and Protocols in a Mars Analogue Arctic Environment; Habitability of the Shallow Subsurface on Mars: Clues from the Meteorites; Mars Analog Rio Tinto Experiment (MARTE): 2003 Drilling Campaign to Search for a Subsurface Biosphere at Rio Tinto Spain; Characterization of the Organic Matter in an Archean Chert (Warrawoona, Australia); and The Solfatara Crater, Italy: Characterization of Hydrothermal Deposits, Biosignatures and Their Astrobiological Implication.

Functionally redundant but dissimilar microbial communities within biogas reactors treating maize silage in co-fermentation with sugar beet silage

PubMed Central

Langer, Susanne G; Ahmed, Sharif; Einfalt, Daniel; Bengelsdorf, Frank R; Kazda, Marian

2015-01-01

Numerous observations indicate a high flexibility of microbial communities in different biogas reactors during anaerobic digestion. Here, we describe the functional redundancy and structural changes of involved microbial communities in four lab-scale continuously stirred tank reactors (CSTRs, 39°C, 12 L volume) supplied with different mixtures of maize silage (MS) and sugar beet silage (SBS) over 80 days. Continuously stirred tank reactors were fed with mixtures of MS and SBS in volatile solid ratios of 1:0 (Continuous Fermenter (CF) 1), 6:1 (CF2), 3:1 (CF3), 1:3 (CF4) with equal organic loading rates (OLR 1.25 kgVS m−3 d−1) and showed similar biogas production rates in all reactors. The compositions of bacterial and archaeal communities were analysed by 454 amplicon sequencing approach based on 16S rRNA genes. Both bacterial and archaeal communities shifted with increasing amounts of SBS. Especially pronounced were changes in the archaeal composition towards Methanosarcina with increasing proportion of SBS, while Methanosaeta declined simultaneously. Compositional shifts within the microbial communities did not influence the respective biogas production rates indicating that these communities adapted to environmental conditions induced by different feedstock mixtures. The diverse microbial communities optimized their metabolism in a way that ensured efficient biogas production. PMID:26200922

History of adaptation determines short-term shifts in performance and community structure of hydrogen-producing microbial communities degrading wheat straw.

PubMed

Valdez-Vazquez, Idania; Morales, Ana L; Escalante, Ana E

2017-11-01

This study addresses the question of ecological interest for the determination of structure and diversity of microbial communities that degrade lignocellulosic biomasses to produce biofuels. Two microbial consortia with different history, native of wheat straw (NWS) and from a methanogenic digester (MD) fed with cow manure, were contrasted in terms of hydrogen performance, substrate disintegration and microbial diversity. NWS outperformed the hydrogen production rate of MD. Microscopic images revealed that NWS acted on the cuticle and epidermis, generating cellulose strands with high crystallinity, while MD degraded deeper layers, equally affecting all polysaccharides. The bacterial composition markedly differed according to the inocula origin. NWS almost solely comprised hydrogen producers of the phyla Firmicutes and Proteobacteria, with 38% members of Enterococcus. After hydrogen fermentation, NWS comprised 8% Syntrophococcus, an acetogen that cleaves aryl ethers of constituent groups on the aromatic components of lignin. Conversely, MD comprised thirteen phyla, primarily including Firmicutes with H 2 -producing members, and Bacteroidetes with non-H 2 -producing members, which reduced the hydrogen performance. Overall, the results of this study provide clear evidence that the history of adaptation of NWS enhanced the hydrogen performance from untreated wheat straw. Further, native wheat straw communities have the potential to refine cellulose fibers and produce biofuels simultaneously. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Diversity of the Sediment Microbial Community in the Aha Watershed (Southwest China) in Response to Acid Mine Drainage Pollution Gradients.

PubMed

Sun, Weimin; Xiao, Tangfu; Sun, Min; Dong, Yiran; Ning, Zengping; Xiao, Enzong; Tang, Song; Li, Jiwei

2015-08-01

Located in southwest China, the Aha watershed is continually contaminated by acid mine drainage (AMD) produced from upstream abandoned coal mines. The watershed is fed by creeks with elevated concentrations of aqueous Fe (total Fe > 1 g/liter) and SO4 (2-) (>6 g/liter). AMD contamination gradually decreases throughout downstream rivers and reservoirs, creating an AMD pollution gradient which has led to a suite of biogeochemical processes along the watershed. In this study, sediment samples were collected along the AMD pollution sites for geochemical and microbial community analyses. High-throughput sequencing found various bacteria associated with microbial Fe and S cycling within the watershed and AMD-impacted creek. A large proportion of Fe- and S-metabolizing bacteria were detected in this watershed. The dominant Fe- and S-metabolizing bacteria were identified as microorganisms belonging to the genera Metallibacterium, Aciditerrimonas, Halomonas, Shewanella, Ferrovum, Alicyclobacillus, and Syntrophobacter. Among them, Halomonas, Aciditerrimonas, Metallibacterium, and Shewanella have previously only rarely been detected in AMD-contaminated environments. In addition, the microbial community structures changed along the watershed with different magnitudes of AMD pollution. Moreover, the canonical correspondence analysis suggested that temperature, pH, total Fe, sulfate, and redox potentials (Eh) were significant factors that structured the microbial community compositions along the Aha watershed. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Influence of high dose of phytase and an emulsifier on performance, apparent metabolisable energy and nitrogen retention in broilers fed on diets containing soy oil or tallow.

PubMed

Zaefarian, F; Romero, L F; Ravindran, V

2015-01-01

The effects of high dose of microbial phytase and an emulsifier on the performance, apparent metabolisable energy (AME) and nitrogen (N) retention in broilers fed on diets containing different fat sources were examined in a 5-week trial. Two fat sources (soy oil and tallow), two inclusion levels of E. coli phytase (500 or 1000 phytase units (FTU)/kg diet) and two inclusion levels of lysolecithin emulsifier (0 or 3.5 g/kg of diet) were evaluated in a 2 × 2 × 2 factorial arrangement of treatments. Throughout the 5-week trial, soy oil supplementation improved weight gain and feed per gain compared with tallow, but had no effect on feed intake. The high dose of phytase increased the weight gain and feed intake and lowered the feed per gain during d 1-21, but had no effect on performance parameters over the whole trial period. An effect of emulsifier was observed for feed intake during d 1-21 and over the whole trial period. Addition of emulsifier increased feed intake compared with diets without emulsifier. During weeks 1, 2, 3 and 5, birds fed on soy oil-based diets had higher nitrogen-corrected AME (AMEN) compared with those fed on tallow-based diets. During weeks 2, 3 and 5, the effect of phytase was significant for AMEN, with the high dose increasing the AMEN. During week 2, AMEN was increased with emulsifier addition. During weeks 1, 2, 3 and 5, birds fed on soy oil-based diets had higher fat retention compared with those fed on tallow-based diets. The high dose of phytase improved the retention of fat during week 5 and the addition of emulsifier resulted in higher fat retention during week 1. During weeks 2, 3 and 5, an interaction between fat source × phytase × emulsifier was observed for N retention. In soy oil-based diets, emulsifier plus 1000 FTU/kg phytase increased N retention compared with other groups, while in tallow-based diets, emulsifier addition increased N retention in diets with 500 FTU/kg, but not in 1000 FTU/kg diet. Overall, the present data suggest that the dietary fat source influenced performance, AMEN and fat retention in broiler chickens. There is opportunity to improve bird performance during d 1-21, AMEN and fat retention with higher doses of microbial phytase. Addition of the emulsifier increased the AMEN during week 2 and tract retention of fat during week 1, but this effect was not translated into improvements in performance.

Loss of Junctional Adhesion Molecule A Promotes Severe Steatohepatitis in Mice on a Diet High in Saturated Fat, Fructose, and Cholesterol.

PubMed

Rahman, Khalidur; Desai, Chirayu; Iyer, Smita S; Thorn, Natalie E; Kumar, Pradeep; Liu, Yunshan; Smith, Tekla; Neish, Andrew S; Li, Hongliang; Tan, Shiyun; Wu, Pengbo; Liu, Xiaoxiong; Yu, Yuanjie; Farris, Alton B; Nusrat, Asma; Parkos, Charles A; Anania, Frank A

2016-10-01

There is evidence from clinical studies that compromised intestinal epithelial permeability contributes to the development of nonalcoholic steatohepatitis (NASH), but the exact mechanisms are not clear. Mice with disruption of the gene (F11r) encoding junctional adhesion molecule A (JAM-A) have defects in intestinal epithelial permeability. We used these mice to study how disruption of the intestinal epithelial barrier contributes to NASH. Male C57BL/6 (control) or F11r(-/-) mice were fed a normal diet or a diet high in saturated fat, fructose, and cholesterol (HFCD) for 8 weeks. Liver and intestinal tissues were collected and analyzed by histology, quantitative reverse-transcription polymerase chain reaction, and flow cytometry. Intestinal epithelial permeability was assessed in mice by measuring permeability to fluorescently labeled dextran. The intestinal microbiota were analyzed using 16S ribosomal RNA sequencing. We also analyzed biopsy specimens from proximal colons of 30 patients with nonalcoholic fatty liver disease (NAFLD) and 19 subjects without NAFLD (controls) undergoing surveillance colonoscopy. F11r(-/-) mice fed a HFCD, but not a normal diet, developed histologic and pathologic features of severe NASH including steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis, whereas control mice fed a HFCD developed only modest steatosis. Interestingly, there were no differences in body weight, ratio of liver weight:body weight, or glucose homeostasis between control and F11r(-/-) mice fed a HFCD. In these mice, liver injury was associated with significant increases in mucosal inflammation, tight junction disruption, and intestinal epithelial permeability to bacterial endotoxins, compared with control mice or F11r(-/-) mice fed a normal diet. The HFCD led to a significant increase in inflammatory microbial taxa in F11r(-/-) mice, compared with control mice. Administration of oral antibiotics or sequestration of bacterial endotoxins with sevelamer hydrochloride reduced mucosal inflammation and restored normal liver histology in F11r(-/-) mice fed a HFCD. Protein and transcript levels of JAM-A were significantly lower in the intestinal mucosa of patients with NAFLD than without NAFLD; decreased expression of JAM-A correlated with increased mucosal inflammation. Mice with defects in intestinal epithelial permeability develop more severe steatohepatitis after a HFCD than control mice, and colon tissues from patients with NAFLD have lower levels of JAM-A and higher levels of inflammation than subjects without NAFLD. These findings indicate that intestinal epithelial barrier function and microbial dysbiosis contribute to the development of NASH. Restoration of intestinal barrier integrity and manipulation of gut microbiota might be developed as therapeutic strategies for patients with NASH. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Comparison of fermentation of diets of variable composition and microbial populations in the rumen of sheep and Rusitec fermenters. II. Protozoa population and diversity of bacterial communities.

PubMed

Martínez, M E; Ranilla, M J; Tejido, M L; Saro, C; Carro, M D

2010-08-01

Four ruminally and duodenally cannulated sheep and 8 Rusitec fermenters were used to determine the effects of dietary characteristics on microbial populations and bacterial diversity. The purpose of the study was to assess how closely fermenters can mimic the differences between diets found in vivo. The 4 experimental diets contained forage to concentrate (F:C) ratios of 70:30 (high forage; HF) or 30:70 (high concentrate; HC) with either alfalfa hay (A) or grass hay (G) as the forage. Total bacterial numbers were greater in the rumen of sheep fed HF diets compared with those fed HC diets, whereas the opposite was found in fermenters. The numbers of cellulolytic bacteria were not affected by F:C ratio in any fermentation system, but cellulolytic numbers were 2.7 and 1.8 times greater in sheep than in fermenters for HF and HC diets, respectively. Neither total bacterial nor cellulolytic numbers were affected by the type of forage in sheep or fermenters. Decreasing F:C ratio increased total protozoa and Entodiniae numbers in sheep by about 29 and 25%, respectively, but it had no effect in fermenters. Isotrichidae and Ophryoscolecinae numbers in sheep were not affected by changing F:C ratio, but both disappeared completely from fermenters fed HC diets. Total protozoa and Entodiniae numbers were greater in sheep fed A diets than in those fed G diets, whereas the opposite was found in fermenters. Results indicate that under the conditions of the present study, protozoa population in Rusitec fermenters was not representative of that in the rumen of sheep fed the same diets. In addition, protozoa numbers in fermenters were 121 and 226 times lower than those in the sheep rumen for HF and HC diets, respectively. The automated ribosomal intergenic spacer analysis of the 16S ribosomal DNA was used to analyze the diversity of liquid- and solid-associated bacteria in both systems. A total of 170 peaks were detected in the automated ribosomal intergenic spacer analysis electropherograms of bacterial pellets across the full set of 64 samples, from which 160 were detected in at least 1 individual from each system (sheep or fermenter). Diversity of liquid-associated bacterial pellets was greater with G diets in fermenters but seemed to be unaffected by diet in sheep. Bacterial diversity in solid-associated bacteria pellets was greater for G diets compared with A diets in sheep and fermenters. Different conditions in the fermenters compared with sheep rumen might have caused a selection of some bacterial strains. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Weaned beef calves fed selenium-biofortified alfalfa hay have an enriched nasal microbiota compared with healthy controls.

PubMed

Hall, Jean A; Isaiah, Anitha; Estill, Charles T; Pirelli, Gene J; Suchodolski, Jan S

2017-01-01

Selenium (Se) is an essential trace mineral important for immune function and overall health of cattle. The nasopharyngeal microbiota in cattle plays an important role in overall respiratory health, especially when stresses associated with weaning, transport, and adaptation to a feedlot affect the normal respiratory defenses. Recent evidence suggests that cattle diagnosed with bovine respiratory disease complex have significantly less bacterial diversity. The objective of this study was to determine whether feeding weaned beef calves Se-enriched alfalfa (Medicago sativa) hay for 9 weeks in a preconditioning program prior to entering the feedlot alters nasal microbiota. Recently weaned beef calves (n = 45) were blocked by sex and body weight, randomly assigned to 3 treatment groups with 3 pens of 5 calves per treatment group, and fed an alfalfa hay based diet for 9 weeks. Alfalfa hay was harvested from fields fertilized with sodium selenate at a rate of 0, 45.0 or 89.9 g Se/ha. Blood samples were collected biweekly and analyzed for whole-blood Se concentrations. Nasal swabs were collected during week 9 from one or two calves from each pen (total n = 16). Calculated Se intake from dietary sources was 3.0, 15.6, and 32.2 mg Se/head/day for calves consuming alfalfa hay with Se concentrations of 0.34 to 2.42 and 5.17 mg Se/kg dry matter, respectively. Whole-blood Se concentrations after 8 weeks of feeding Se-fertilized alfalfa hay were dependent upon Se-application rates (0, 45.0, or 89.9 g Se/ha) and were 155, 345, and 504 ng/mL (PLinear < 0.0001). Microbial DNA was extracted from nasal swabs and amplified and sequenced. Alpha rarefaction curves comparing the species richness (observed OTUs) and overall diversity (Chao1, Observed OTU, and Shannon index) between calves fed selenium-biofortified alfalfa hay compared with control calves showed that Se-supplementation tended to be associated with an enriched nasal microbiota. ANOSIM of unweighted UniFrac distances showed that calves fed high Se-biofortified alfalfa hay clustered separately when compared with control calves in the PCoA plot (R = 0.216, P = 0.04). The bacterial orders Lactobacillales and Flavobacteriales were increased in healthy control calves compared with Clostridiales and Bacteroidales being increased in calves fed Se-biofortified alfalfa hay. Although there were strong trends, no significant differences were noted for any of the bacterial taxa. Based upon these findings, we suggest that weaned beef calves fed Se-biofortified hay tend to have an enriched nasal microbiota. Feeding Se-biofortified alfalfa hay to weaned beef calves prior to entering the feedlot is a strategy for increasing nasopharyngeal microbial diversity.

Nutrient intake, digestibility and performance of Gaddi kids supplemented with tea seed or tea seed saponin extract

PubMed Central

Kumar, M.; Kannan, A.; Bhar, R.; Gulati, A.; Gaurav, A.; Sharma, V. K.

2017-01-01

Objective An experiment was conducted to determine the nutrient intake, digestibility, microbial protein synthesis, haemato-biochemical attributes, immune response and growth performance of Gaddi kids fed with oat fodder based basal diet supplemented with either tea seed or tea seed saponin (TSS) extract. Methods Eighteen male kids, 7.03±0.16 months of age and 19.72±0.64 kg body weight, were distributed into three groups, T0 (control), T1, and T2, consisting of 6 animals each in a completely randomized design. The kids were fed a basal diet consisting of concentrate mixture and oat fodder (50:50). Animals in group III (T2) were supplemented with TSS at 0.4% of dry matter intake (DMI), and group II (T1) were supplemented with tea seed at 2.6% of DMI to provide equivalent dose of TSS as in T2. Two metabolism trials were conducted, 1st after 21 days and 2nd after 90 days of feeding to evaluate the short term and long term effects of supplementation. Results The tea seed (T1) or TSS (T2) supplementation did not affect DMI as well as the digestibility of dry matter, organic matter, crude protein, neutral detergent fibre, and acid detergent fibre. Nutritive value of diet and plane of nutrition were also comparable for both the periods. However, the average daily gain and feed conversion ratio (FCR) were improved (p<0.05) for T1 and T2 as compared to T0. The microbial protein supply was also higher (p<0.05) for T1 and T2 for both the periods. There was no effect of supplementation on most blood parameters. However, the triglyceride and low density lipoprotein cholesterol levels decreased (p<0.05) and high density lipoprotein-cholesterol level increased (p<0.05) in T2 as compared with T0 and T1. Supplementation also did not affect the cell mediated and humoral immune response in goats. Conclusion Tea seed at 2.6% of DMI and TSS at 0.4% DMI can be fed to Gaddi goats to improve growth rate, FCR and microbial protein synthesis. PMID:27608635

Direct and indirect influence of parental bedrock on streambed microbial community structure in forested streams.

PubMed

Mosher, Jennifer J; Findlay, Robert H

2011-11-01

A correlative study was performed to determine if variation in streambed microbial community structure in low-order forested streams can be directly or indirectly linked to the chemical nature of the parental bedrock of the environments through which the streams flow. Total microbial and photosynthetic biomass (phospholipid phosphate [PLP] and chlorophyll a), community structure (phospholipid fatty acid analysis), and physical and chemical parameters were measured in six streams, three located in sandstone and three in limestone regions of the Bankhead National Forest in northern Alabama. Although stream water flowing through the two different bedrock types differed significantly in chemical composition, there were no significant differences in total microbial and photosynthetic biomass in the sediments. In contrast, sedimentary microbial community structure differed between the bedrock types and was significantly correlated with stream water ion concentrations. A pattern of seasonal variation in microbial community structure was also observed. Further statistical analysis indicated dissolved organic matter (DOM) quality, which was previously shown to be influenced by geological variation, correlated with variation in bacterial community structure. These results indicate that the geology of underlying bedrock influences benthic microbial communities directly via changes in water chemistry and also indirectly via stream water DOM quality.

Development and Reliability Testing of the FEDS System for Classifying Glenohumeral Instability

PubMed Central

Kuhn, John E.; Helmer, Tara T.; Dunn, Warren R.; Throckmorton V, Thomas W.

2010-01-01

Background Classification systems for glenohumeral instability (GHI) are opinion based, not validated, and poorly defined. This study is designed to methodologically develop and test a GHI classification system. Methods: Classification System Development A systematic literature review identified 18 systems for classifying GHI. The frequency characteristics used was recorded. Additionally 31 members of the American Shoulder and Elbow Surgeons responded to a survey to identify features important to characterize GHI. Frequency, Etiology, Direction, and Severity (FEDS), were found to be most important. Frequency was defined as solitary (one episode), occasional (2–5x/year), or frequent (>5x/year). Etiology was defined as traumatic or atraumatic. Direction referred to the primary direction of instability (anterior, posterior, or inferior). Severity was defined as either subluxation or dislocation. Methods: Reliability Testing Fifty GHI patients completed a questionnaire at their initial visit. One of six sports medicine fellowship trained physicians completed a similar questionnaire after examining the patient. Patients returned after two weeks and were examined by the original physician and two other physicians. Inter- and intra-rater agreement for the FEDS classification system was calculated. Results Agreement between patients and physicians was lowest for frequency (39%; k=0.130) and highest for direction (82%; k=0.636). Physician intra-rater agreement was 84– 97% for the individual FEDS characteristics (k=0.69 to 0.87)). Physician inter-rater agreement ranged from 82–90% (k=0.44 to 0.76). Conclusions The FEDS system has content validity and is highly reliable for classifying GHI. Physical examination using provocative testing to determine the primary direction of instability produces very high levels of inter- and intra-rater agreement. Level of evidence Level II, Development of Diagnostic Criteria with Consecutive Series of Patients, Diagnosis Study. PMID:21277809

[Electricity generation and contaminants degradation performances of a microbial fuel cell fed with Dioscorea zingiberensis wastewater].

PubMed

Li, Hui; Zhu, Xiu-Ping; Xu, Nan; Ni, Jin-Ren

2011-01-01

The electricity generation performance of a microbial fuel cell (MFC) utilizing Dioscorea zingiberensis wastewater was studied with an H-shape reactor. Indexes including pH, conductivity, oxidation peak potential and chemical oxygen demand (COD) of the anolyte were monitored to investigate the contaminants degradation performance of the MFC during the electricity generation process, besides, contaminant ingredients in anodic influent and effluent were analyzed by GC-MS and IR spectra as well. The maximum power density of the MFC could achieve 118.1 mW/m2 and the internal resistance was about 480 omega. Connected with a 1 000 omega external resistance, the output potential was about 0.4 V. Fed with 5 mL Dioscorea zingiberensis wastewater, the electricity generation lasted about 133 h and the coulombic efficiency was about 3.93%. At the end of electricity generation cycle, COD decreased by 90.1% while NH4(+) -N decreased by 66.8%. Furfural compounds, phenols and some other complicated organics could be decomposed and utilized in the electricity generation process, and the residual contaminants in effluent included some long-chain fatty acids, esters, ethers, and esters with benzene ring, cycloalkanes, cycloolefins, etc. The results indicate that MFC, which can degrade and utilize the organic contaminants in Dioscorea zingiberensis wastewater simultaneously, provides a new approach for resource recovery treatment of Dioscorea zingiberensis wastewater.

Polyhydroxyalkanoate accumulation ability and associated microbial community in activated sludge-derived acetate-fed microbial cultures enriched under different temperature and pH conditions.

PubMed

Inoue, Daisuke; Suzuki, Yuta; Sawada, Kazuko; Sei, Kazunari

2018-03-01

The influence of temperature and pH during enrichment on the polyhydroxyalkanoate (PHA) accumulation ability and composition of PHA-accumulating microorganisms (PHAAMOs) in enrichment cultures was investigated. Enrichment of PHAAMOs from activated sludge was conducted in acetate-fed sequencing batch reactors using a feast-famine regime under different temperature (20°C, 28°C, and 36°C) and pH (controlled at 7.2 or not) conditions. PHA accumulation ability, which was evaluated in nitrogen- and phosphorus-deficient 24-h single-batch cultures, was greatly enhanced by enrichment, irrespective of the temperature and pH. Enrichment at 20°C or 28°C and without pH control seemed most appropriate for strong PHA accumulation. Analyses of the PHAAMO composition by the clone library method targeting phaC genes, which encode the class I and II PHA synthases, revealed that Burkholderiales were the dominant PHAAMOs in the seed sludge, while Rhodocyclales, specifically Azoarcus spp. and Thauera spp., were dominant after enrichment without pH control, showing a strong ability to accumulate PHA. The results indicated that Azoarcus spp. and Thauera spp. are key PHAAMOs in an enrichment culture based on the feast-famine method, with high PHA accumulation ability. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Characterization of a microfluidic microbial fuel cell as a power generator based on a nickel electrode.

PubMed

Mardanpour, Mohammad Mahdi; Yaghmaei, Soheila

2016-05-15

This study reports the fabrication of a microfluidic microbial fuel cell (MFC) using nickel as a novel alternative for conventional electrodes and a non-phatogenic strain of Escherichia coli as the biocatalyst. The feasibility of a microfluidic MFC as an efficient power generator for production of bioelectricity from glucose and urea as organic substrates in human blood and urine for implantable medical devices (IMDs) was investigated. A maximum open circuit potential of 459 mV was achieved for the batch-fed microfluidic MFC. During continuous mode operation, a maximum power density of 104 Wm(-3) was obtained with nutrient broth. For the glucose-fed microfluidic MFC, the maximum power density of 5.2 μW cm(-2) obtained in this study is significantly greater than the power densities reported previously for microsized MFCs and glucose fuel cells. The maximum power density of 14 Wm(-3) obtained using urea indicates the successful performance of a microfluidic MFC using human excreta. It features high power density, self-regeneration, waste management and a low production cost (<$1), which suggest it as a promising alternative to conventional power supplies for IMDs. The performance of the microfluidic MFC as a power supply was characterized based on polarization behavior and cell potential in different substrates, operational modes, and concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate

PubMed Central

Pronk, M; Abbas, B; Kleerebezem, R; van Loosdrecht, M C M

2015-01-01

The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens and prevented unwanted methane formation. In absence of methanogens, methanol was converted aerobically, while granule formation remained stable. At high SRT values (51 days), γ-Proteobacteria were responsible for acetate removal through anaerobic uptake and subsequent aerobic growth on storage polymers formed [so called metabolism of glycogen-accumulating organisms (GAO)]. When lowering the SRT (24 days), Defluviicoccus-related organisms (cluster II) belonging to the α-Proteobacteria outcompeted acetate consuming γ-Proteobacteria at 35°C. DNA from the Defluviicoccus-related organisms in cluster II was not extracted by the standard DNA extraction method but with liquid nitrogen, which showed to be more effective. Remarkably, the two GAO types of organisms grew separately in two clearly different types of granules. This work further highlights the potential of aerobic granular sludge systems to effectively influence the microbial communities through sludge age control in order to optimize the wastewater treatment processes. PMID:26059251

Influence of co-substrate on textile wastewater treatment and microbial community changes in the anaerobic biological sulfate reduction process.

PubMed

Rasool, Kashif; Mahmoud, Khaled A; Lee, Dae Sung

2015-12-15

This study investigated the anaerobic treatment of sulfate-rich synthetic textile wastewater in three sulfidogenic sequential batch reactors (SBRs). The experimental protocol was designed to examine the effect of three different co-substrates (lactate, glucose, and ethanol) and their concentrations on wastewater treatment performance. Sulfate reduction and dye degradation were improved when lactate and ethanol were used as electron donors, as compared with glucose. Moreover, under co-substrate limited concentrations, color, sulfate, and chemical oxygen demand (COD) removal efficiencies were declined. By reducing co-substrate COD gradually from 3000 to 500 mg/L, color removal efficiencies were decreased from 98.23% to 78.46%, 63.37%, and 69.10%, whereas, sulfate removal efficiencies were decreased from 98.42%, 82.35%, and 87.0%, to 30.27%, 21.50%, and 10.13%, for lactate, glucose, and ethanol fed reactors, respectively. Fourier transform infrared spectroscopy (FTIR) and total aromatic amine analysis revealed lactate to be a potential co-substrate for further biodegradation of intermediate metabolites formed after dye degradation. Pyrosequencing analysis showed that microbial community structure was significantly affected by the co-substrate. The reactor with lactate as co-substrate showed the highest relative abundance of sulfate reducing bacteria (SRBs), followed by ethanol, whereas the glucose-fed reactor showed the lowest relative abundance of SRB. Copyright © 2015 Elsevier B.V. All rights reserved.

Microbial production of volatile sulphur compounds in the large intestine of pigs fed two different diets.

PubMed

Poulsen, H V; Jensen, B B; Finster, K; Spence, C; Whitehead, T R; Cotta, M A; Canibe, N

2012-07-01

  To investigate the production of volatile sulphur compounds (VSC) in the segments of the large intestine of pigs and to assess the impact of diet on this production.   Pigs were fed two diets based on either wheat and barley (STD) or wheat and dried distillers grains with solubles (DDGS). Net production of VSC and potential sulphate reduction rate (SRR) (sulphate saturated) along the large intestine were determined by means of in vitro incubations. The net production rate of hydrogen sulphide and potential SRR increased from caecum towards distal colon and were significantly higher in the STD group. Conversely, the net methanethiol production rate was significantly higher in the DDGS group, while no difference was observed for dimethyl sulphide. The number of sulphate-reducing bacteria and total bacteria were determined by quantitative PCR and showed a significant increase along the large intestine, whereas no diet-related differences were observed.   VSC net production varies widely throughout the large intestine of pigs and the microbial processes involved in this production can be affected by diet.   This first report on intestinal production of all VSC shows both spatial and dietary effects, which are relevant to both bowel disease- and odour mitigation research. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Cinnamaldehyde supplementation prevents fasting-induced hyperphagia, lipid accumulation, and inflammation in high-fat diet-fed mice.

PubMed

Khare, Pragyanshu; Jagtap, Sneha; Jain, Yachna; Baboota, Ritesh K; Mangal, Priyanka; Boparai, Ravneet K; Bhutani, Kamlesh K; Sharma, Shyam S; Premkumar, Louis S; Kondepudi, Kanthi K; Chopra, Kanwaljit; Bishnoi, Mahendra

2016-01-01

Cinnamaldehyde, a bioactive component of cinnamon, is increasingly gaining interest for its preventive and therapeutic effects against metabolic complications like type-2 diabetes. This study is an attempt to understand the effect of cinnamaldehyde in high-fat diet (HFD)-associated increase in fasting-induced hyperphagia and related hormone levels, adipose tissue lipolysis and inflammation, and selected cecal microbial count in mice. Cinnamaldehyde, at 40 µM dose, prevented lipid accumulation and altered gene expression toward lipolytic phenotype in 3T3-L1 preadipocyte cell lines. In vivo, cinnamaldehyde coadministration prevented HFD-induced body weight gain, decreased fasting-induced hyperphagia, as well as circulating leptin and leptin/ghrelin ratio. In addition to that, cinnamaldehyde altered serum biochemical parameters related to lipolysis, that is, glycerol and free fatty acid levels. At transcriptional level, cinnamaldehyde increased anorectic gene expression in hypothalamus and lipolytic gene expression in visceral white adipose tissue. Furthermore, cinnamaldehyde also decreased serum IL-1β and inflammatory gene expression in visceral white adipose tissue. However, cinnamaldehyde did not modulate the population of selected gut microbial (Lactobacillus, Bifidibaceria, and Roseburia) count in cecal content. In conclusion, cinnamaldehyde increased adipose tissue lipolysis, decreased fasting-induced hyperphagia, normalized circulating levels of leptin/ghrelin ratio, and reduced inflammation in HFD-fed mice, which augurs well for its antiobesity role. © 2016 International Union of Biochemistry and Molecular Biology.

The interacting roles of climate, soils, and plant production on soil microbial communities at a continental scale

USGS Publications Warehouse

Waldrop, Mark P.; Holloway, JoAnn M.; Smith, David; Goldhaber, Martin B.; Drenovsky, R.E.; Scow, K.M.; Dick, R.; Howard, Daniel M.; Wylie, Bruce K.; Grace, James B.

2017-01-01

Soil microbial communities control critical ecosystem processes such as decomposition, nutrient cycling, and soil organic matter formation. Continental scale patterns in the composition and functioning of microbial communities are related to climatic, biotic, and edaphic factors such as temperature and precipitation, plant community composition, and soil carbon, nitrogen, and pH. Although these relationships have been well explored individually, the examination of the factors that may act directly on microbial communities vs. those that may act indirectly through other ecosystem properties has not been well developed. To further such understanding, we utilized structural equation modeling (SEM) to evaluate a set of hypotheses about the direct and indirect effects of climatic, biotic, and edaphic variables on microbial communities across the continental United States. The primary goals of this work were to test our current understanding of the interactions among climate, soils, and plants in affecting microbial community composition, and to examine whether variation in the composition of the microbial community affects potential rates of soil enzymatic activities. A model of interacting factors created through SEM shows several expected patterns. Distal factors such as climate had indirect effects on microbial communities by influencing plant productivity, soil mineralogy, and soil pH, but factors related to soil organic matter chemistry had the most direct influence on community composition. We observed that both plant productivity and soil mineral composition were important indirect influences on community composition at the continental scale, both interacting to affect organic matter content and microbial biomass and ultimately community composition. Although soil hydrolytic enzymes were related to the moisture regime and soil carbon, oxidative enzymes were also affected by community composition, reflected in the abundance of soil fungi. These results highlight that soil microbial communities can be modeled within the context of multiple interacting ecosystem properties acting both directly and indirectly on their composition and function, and this provides a rich and informative context with which to examine communities. This work also highlights that variation in climate, microbial biomass, and microbial community composition can affect maximum rates of soil enzyme activities, potentially influencing rates of decomposition and nutrient mineralization in soils.

The effect of microbial phytase on ileal phosphorus and amino acid digestibility in the broiler chicken.

PubMed

Rutherfurd, S M; Chung, T K; Moughan, P J

2002-09-01

1. The study aimed to assess the effect of a commercially available microbial phytase on phytate phosphorus and total phosphorus content at the terminal ileum as well as true ileal amino acid digestibility. 2. Five diets, each containing a different plant-based feedstuff, were supplemented with microbial phytase and fed, along with a non-supplemented corresponding diet, to 28-d-old broiler chickens, Chromic oxide was used as an indigestible marker. Ileal contents were collected and analysed, along with the diets, for total phosphorus, phytate phosphorus and amino acids. 3. Endogenous phosphorus determined at the terminal ileum was 272 +/- 108 mg/kg food dry matter (mean +/- SE). Endogenous ileal amino acid flows ranged from 58 +/- 10 mg/kg food dry matter for methionine to 568 +/- 47 mg/kg food dry matter for glutamic acid. 4. Supplementation with microbial phytase resulted in a significantly greater phytate P disappearance from the terminal ileum for rice bran (17% units), but not for soyabean meal, maize, wheat or rapeseed meal. Similarly total phosphorus digestibility was significantly (P < 0.05) higher when microbial phytase was added to the rice-bran-based diet but not for any of the other feedstuffs. 5. Amino acid digestibility was significantly greater in the presence of microbial phytase for all the amino acids examined in wheat, for several of the amino acids each in maize and rapeseed meal and for one amino acid in rice bran and soyabean meal. The average increase in amino acid digestibility for those amino acids affected, was 13, 6, 10, 7 and 12% units for wheat, maize, rapeseed meal, rice bran and soyabean meal, respectively. 6. It appears that microbial phytase improves phosphorus digestibility and amino acid digestibility for certain plant-based feedstuffs.

Effects of fat and/or methionine hydroxy analog added to a molasses-urea-based supplement on ruminal and postruminal digestion and duodenal flow of nutrients in beef steers consuming low-quality lovegrass hay.

PubMed

Lopez, R; Pulsipher, G D; Guerra-Liera, J E; Soto-Navarro, S A; Balstad, L A; Petersen, M K; Dhuyvetter, D V; Brown, M S; Krehbiel, C R

2016-06-01

Five crossbred beef steers (initial BW = 338.6 ± 7.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 × 5 Latin square design experiment to evaluate the effects of methionine hydroxy analog (MHA) and/or yellow grease (fat) added to a molasses-urea-based supplement on intake and characteristics of digestion. Steers were fed low-quality hay (long-stem lovegrass : 3.3% CP, 76.8% NDF; DM basis) ad libitum and supplemented with 0.91 kg/d (as fed) of 1 of 4 supplements in a 2 × 2 + 1 factorial arrangement of treatments. Supplemental treatments were 1) control (no supplement, NC); 2) molasses-urea liquid supplement (U); 3) U containing (as-fed basis) 1.65% MHA (UM); 4) U containing (as-fed basis) 12% fat (UF); and 5) U containing (as-fed basis) 1.65% MHA and 12% fat (UMF). Total and forage OM intake (kg/d and as % of BW) increased ( < 0.01) with molasses-urea, decreased ( ≤ 0.04) with MHA, and were not affected ( = 0.61) with fat supplementation. Total tract NDF digestibility increased ( = 0.01) with molasses-urea supplementation, and was less ( = 0.01) for fat than for nonfat supplementation. Total and microbial N flowing to the duodenum increased ( = 0.01) with molasses-urea supplementation. Although, total N flowing to duodenum was not affected ( = 0.27), microbial N decreased ( = 0.01), and nonammonia nonmicrobial N (NANMN) increased ( = 0.01) with fat supplementation. Extent of in situ OM and NDF digestibility at 96 h increased ( = 0.01) with molasses-urea supplementation, but were not affected ( ≥ 0.14) by either MHA or fat supplementation. Duodenal flow of total AA, essential AA, and nonessential AA increased ( ≤ 0.02) with molasses-urea supplementation. Total and nonessential serum AA concentration decreased ( < 0.01) with molasses-urea supplementation. Total ruminal VFA concentration increased ( = 0.01) with molasses-urea supplementation, and was not affected ( ≥ 0.14) by MHA or fat supplementation. Fat can be used in molasses-urea liquid supplements for cattle consuming low-quality forage to increase energy intake without negatively affecting forage intake or characteristics of digestion. However, adding MHA did not further improve the response to urea supplementation of cattle consuming low-quality forage. Conversely, the inclusion of MHA on urea supplement decreased forage intake.

Microbial fuel cells: From fundamentals to applications. A review.

PubMed

Santoro, Carlo; Arbizzani, Catia; Erable, Benjamin; Ieropoulos, Ioannis

2017-07-15

In the past 10-15 years, the microbial fuel cell (MFC) technology has captured the attention of the scientific community for the possibility of transforming organic waste directly into electricity through microbially catalyzed anodic, and microbial/enzymatic/abiotic cathodic electrochemical reactions. In this review, several aspects of the technology are considered. Firstly, a brief history of abiotic to biological fuel cells and subsequently, microbial fuel cells is presented. Secondly, the development of the concept of microbial fuel cell into a wider range of derivative technologies, called bioelectrochemical systems, is described introducing briefly microbial electrolysis cells, microbial desalination cells and microbial electrosynthesis cells. The focus is then shifted to electroactive biofilms and electron transfer mechanisms involved with solid electrodes. Carbonaceous and metallic anode materials are then introduced, followed by an explanation of the electro catalysis of the oxygen reduction reaction and its behavior in neutral media, from recent studies. Cathode catalysts based on carbonaceous, platinum-group metal and platinum-group-metal-free materials are presented, along with membrane materials with a view to future directions. Finally, microbial fuel cell practical implementation, through the utilization of energy output for practical applications, is described.

Microbial fuel cells: From fundamentals to applications. A review

NASA Astrophysics Data System (ADS)

Santoro, Carlo; Arbizzani, Catia; Erable, Benjamin; Ieropoulos, Ioannis

2017-07-01

In the past 10-15 years, the microbial fuel cell (MFC) technology has captured the attention of the scientific community for the possibility of transforming organic waste directly into electricity through microbially catalyzed anodic, and microbial/enzymatic/abiotic cathodic electrochemical reactions. In this review, several aspects of the technology are considered. Firstly, a brief history of abiotic to biological fuel cells and subsequently, microbial fuel cells is presented. Secondly, the development of the concept of microbial fuel cell into a wider range of derivative technologies, called bioelectrochemical systems, is described introducing briefly microbial electrolysis cells, microbial desalination cells and microbial electrosynthesis cells. The focus is then shifted to electroactive biofilms and electron transfer mechanisms involved with solid electrodes. Carbonaceous and metallic anode materials are then introduced, followed by an explanation of the electro catalysis of the oxygen reduction reaction and its behavior in neutral media, from recent studies. Cathode catalysts based on carbonaceous, platinum-group metal and platinum-group-metal-free materials are presented, along with membrane materials with a view to future directions. Finally, microbial fuel cell practical implementation, through the utilization of energy output for practical applications, is described.

Nitrogen digestion and urea recycling in Hokkaido native horses fed hay-based diets.

PubMed

Obitsu, Taketo; Hata, Hiroshi; Taniguchi, Kohzo

2015-02-01

Nitrogen (N) digestion and urea-N metabolism in Hokkaido native horses fed roughage-based diets containing different types and levels of protein sources were studied. Horses (173 ± 4.8 kg) fitted with an ileum cannula were fed four diets consisting of 100% timothy hay (TH), 88% TH and 12% soybean meal (SBM), 79% TH and 21% SBM, and 51% TH and 49% alfalfa hay at 2.2% of body weight. Dietary protein content varied from 5% to 15% of dry matter. Apparent N digestibilities in the pre-cecum and total tract for the TH diet were lower than those for other diets. However, the proportion of post-ileum N digestion to N intake was not affected by the diets. Urea-N production was linearly related to N intake, but gut urea-N entry was not affected by the diets. The proportion of gut urea-N entry to urea-N production tended to be higher for the TH diet (57%) than the two SBM diets (39%). Anabolic use of urea-N entering the gut was not affected by the diets (20-36% of gut urea-N entry). These results indicate that urea-N recycling provides additional N sources for microbial fermentation in the hindgut of Hokkaido native horses fed low-quality roughages. © 2014 Japanese Society of Animal Science.

Epifluorescent direct counts of bacteria and viruses from topsoil of various desert dust storm regions

USGS Publications Warehouse

Gonzalez-Martin, Cristina; Teigell-Perez, Nuria; Lyles, Mark; Valladares, Basilio; Griffin, Dale W.

2013-01-01

Topsoil from arid regions is the main source of dust clouds that move through the earth's atmosphere, and microbial communities within these soils can survive long-range dispersion. Microbial abundance and chemical composition were analyzed in topsoil from various desert regions. Statistical analyses showed that microbial direct counts were strongly positively correlated with calcium concentrations and negatively correlated with silicon concentrations. While variance between deserts was expected, it was interesting to note differences between sample sites within a given desert region, illustrating the 'patchy' nature of microbial communities in desert environments.

Influence of Phytase Transgenic Corn on the Intestinal Microflora and the Fate of Transgenic DNA and Protein in Digesta and Tissues of Broilers

PubMed Central

Li, Sufen; Li, Ang; Zhang, Liyang; Liu, Zhenhua; Luo, Xugang

2015-01-01

An experiment was conducted to investigate the effect of phytase transgenic corn (PTC) on intestinal microflora, and the fate of transgenic DNA and protein in the digesta and tissues of broilers. A total of 160 1-day-old Arbor Acres commercial male broilers were randomly assigned to 20 cages (8 chicks per cage) with 10 cages (replicates) for each treatment. Birds were fed with a diet containing either PTC (54.0% during 1–21 days and 61.0% during 22–42 days) or non-transgenic isogenic control corn (CC) for a duration of 42 days. There were no significant differences (P>0.05) between birds fed with the PTC diets and those fed with the CC diets in the quantities of aerobic bacteria, anaerobic bacteria, colibacillus and lactobacilli, or microbial diversities in the contents of ileum and cecum. Transgenic phyA2 DNA was not detected, but phyA2 protein was detected in the digesta of duodenum and jejunum of broilers fed with the PTC diets. Both transgenic phyA2 DNA and protein fragments were not found in the digesta of the ileum and rectum, heart, liver, kidney, and breast or thigh muscles of broilers fed with the PTC diets. It was concluded that PTC had no adverse effect on the quantity and diversity of gut microorganisms; Transgenic phyA2 DNA or protein was rapidly degraded in the intestinal tract and was not transferred to the tissues of broilers. PMID:26599444

Microbial Contamination of Chicken Wings: An Open-Ended Laboratory Project.

ERIC Educational Resources Information Center

Deutch, Charles E.

2001-01-01

Introduces the chicken wing project in which students assess the microbial contamination of chicken wings for the safety of foods. Uses the colony counting technique and direct wash fluid examination for determining the microbial contamination, and investigates methods to reduce the level of microbial contamination. (Contains 14 references.) (YDS)

The Concentrations of Rumen Fluid Volatile Fatty Acids and Ammonia, and Rumen Microbial Protein Production in Sheep Given Feed During the Day and Night Time

NASA Astrophysics Data System (ADS)

Gumilar, D. A. K. W.; Rianto, E.; Arifin, M.

2018-02-01

An experimental study was carried out to investigate the concentrations of volatile (VFA), ammonia and microbial protein production of rumen fluid in sheep given fedd during the day and at night. This study used 12 fat-tailed rams aged 12-18 months and weighed 24,12 ± 25 kg (CV = 10,51%). The rams were fed a complete feed containing 16.64% protein and 68,33% total digestible nutrients (TDN). The rams were allocated into a completely randomised design with 3 treatments and 4 replications. The treatments applied were: T1: day time feeding (6.00 hrs - 18.00 hrs); T2: night time feeding (18.00 hrs - 6.00 hrs); and T3: day and night time feedings (6.00 hrs - 6.00 hrs). The parameters observed were dry matter intake (DMI), rumen VFA concentration, rumen ammonia concentration, rumen rmicrobial protein production and the efficiency of rumen microbial protein production. The results showed that feeding time did not significantly affect (P>0.05) all the parameters observed. Dry matter intake, VFA concentration, ammonia concentration, the microbial protein production of rumen fluid and the efficiency of microbial protein production were 1,073g/d, 49.69 mmol; 4.77 mg N/100 ml, 12,111 g/d and 19.96 g per kg digestible organic matter intake (DOMI), respectively. It is concluded that feeding time did not affect DMI, condition of rumen fluid and rumen microbial protein production in sheep.

Studies of indirect and direct effects of hypervitaminosis A on rat bone by comparing free access to food and pair-feeding.

PubMed

Lind, Thomas; Lind, P Monica; Hu, Lijuan; Melhus, Håkan

2018-04-26

The most prominent features of hypervitaminosis A in rats are spontaneous fractures and anorexia. Since caloric restriction induces alterations in bone, some effects could be secondary to loss of appetite. To clarify the mechanisms behind vitamin A-induced bone fragility it is necessary to distinguish between direct and indirect effects. In this study we compared rats fed high doses of vitamin A both with pair-fed controls, which were fed the same amount of chow as that consumed by the vitamin A group to keep food intake the same, and to controls with free access to food. In contrast to the pair-fed animals, rats in the free access group fed high doses of vitamin A for 7 days had 13% lower food intake, 15% lower body weight, and 2.7% shorter femurs compared with controls. In addition, serum biomarkers of bone turnover were reduced. Peripheral quantitative computed tomography of the femurs showed that the bone mineral content, cross sectional area, and periosteal circumference were similarly reduced in the pair-fed and free access groups. However, bone mineral density (BMD) and cortical parameters were only significantly decreased in the free access group. Our data indicate that the major direct short-term effect of high doses of vitamin A on rat bone is a reduced bone diameter, whereas the effects on bone length, serum biomarkers of bone turnover, BMD, and bone cortex appear to be mainly indirect, caused by a systemic toxicity with loss of appetite, reduced food intake, and general effects on growth.

Effect of feeding mode and dilution on the performance and microbial community population in anaerobic digestion of food waste.

PubMed

Park, Jong-Hun; Kumar, Gopalakrishnan; Yun, Yeo-Myeong; Kwon, Joong-Chun; Kim, Sang-Hyoun

2018-01-01

The effect of feeding mode and dilution was studied in anaerobic digestion of food waste. An upflow anaerobic digester with a settler was fed at six different organic loading rates (OLRs) from 4.6 to 8.6kgCOD/m 3 /d for 200days. The highest methane productivity of 2.78LCH 4 /L/d was achieved at 8.6kgCOD/m 3 /d during continuous feeding of diluted FW. Continuous feeding of diluted food waste showed more stable and efficient performance than stepwise feeding of undiluted food waste. Sharp increase in propionate concentration attributed towards deterioration of the digester performances in stepwise feeding of undiluted food waste. Microbial communities at various OLRs divulged that the microbial distribution in the continuous feeding of diluted food waste was not significantly perturbed despite the increase of OLR up to 8.6kgCOD/m 3 /d, which was contrast to the unstable distribution in stepwise feeding of undiluted food waste at 6.1kgCOD/m 3 /d. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evidence of soluble microbial products accelerating chloramine decay in nitrifying bulk water samples.

PubMed

Bal Krishna, K C; Sathasivan, Arumugam; Chandra Sarker, Dipok

2012-09-01

The discovery of a microbially derived soluble product that accelerates chloramine decay is described. Nitrifying bacteria are believed to be wholly responsible for rapid chloramine loss in drinking water systems. However, a recent investigation showed that an unidentified soluble agent significantly accelerated chloramine decay. The agent was suspected to be either natural organic matter (NOM) or soluble microbial products (SMPs). A laboratory scale reactor was fed chloraminated reverse osmosis (RO) treated water to eliminate the interference from NOM. Once nitrification had set in, experiments were conducted on the reactor and feed waters to determine the identity of the component. The study showed the presence of SMPs released by microbes in severely nitrified waters. Further experiments proved that the SMPs significantly accelerated chloramine decay, probably through catalytic reaction. Moreover, application of common protein denaturing techniques stopped the reaction implying that the compound responsible was likely to be a protein. This significant finding will pave the way for better control of chloramine in the distribution systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

High-Fat Diet Consumption Induces Microbiota Dysbiosis and Intestinal Inflammation in Zebrafish.

PubMed

Arias-Jayo, Nerea; Abecia, Leticia; Alonso-Sáez, Laura; Ramirez-Garcia, Andoni; Rodriguez, Alfonso; Pardo, Miguel A

2018-05-07

Energy-dense foods and overnutrition represent major starting points altering lipid metabolism, systemic inflammation and gut microbiota. The aim of this work was to investigate the effects of a high-fat diet (HFD) over a period of 25 days on intestinal microbiota and inflammation in zebrafish. Microbial composition of HFD-fed animals was analysed and compared to controls by 16S rRNA sequencing and quantitative PCR. The expression level on several genes related to inflammation was tested. Furthermore, microscopic assessment of the intestine was performed in both conditions. The consumption of the HFD resulted in microbial dysbiosis, characterised by an increase in the relative abundance of the phylum Bacteroidetes. Moreover, an emerging intestinal inflammation via NF-κβ activation was confirmed by the overexpression of several genes related to signalling receptors, antimicrobial metabolism and the inflammatory cascade. The intestinal barrier was also damaged, with an increase of goblet cell mucin production. This is the first study performed in zebrafish which suggests that the consumption of a diet enriched with 10% fat changes the intestinal microbial community composition, which was correlated with low-grade inflammation.

Effect of high loading on substrate utilization kinetics and microbial community structure in super fast submerged membrane bioreactor.

PubMed

Sözen, S; Çokgör, E U; Başaran, S Teksoy; Aysel, M; Akarsubaşı, A; Ergal, I; Kurt, H; Pala-Ozkok, I; Orhon, D

2014-05-01

The study investigated the effect of high substrate loading on substrate utilization kinetics, and changes inflicted on the composition of the microbial community in a superfast submerged membrane bioreactor. Submerged MBR was sequentially fed with a substrate mixture and acetate; its performance was monitored at steady-state, at extremely low sludge age values of 2.0, 1.0 and 0.5d, all adjusted to a single hydraulic retention time of 8.0 h. Each MBR run was repeated when substrate feeding was increased from 200 mg COD/L to 1000 mg COD/L. Substrate utilization kinetics was altered to significantly lower levels when the MBR was adjusted to higher substrate loadings. Molecular analysis of the biomass revealed that variable process kinetics could be correlated with parallel changes in the composition of the microbial community, mainly by a replacement mechanism, where newer species, better adapted to the new growth conditions, substituted others that are washed out from the system. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbiome analysis of dairy cows fed pasture or total mixed ration diets.

PubMed

de Menezes, Alexandre B; Lewis, Eva; O'Donovan, Michael; O'Neill, Brendan F; Clipson, Nicholas; Doyle, Evelyn M

2011-11-01

Understanding rumen microbial ecology is essential for the development of feed systems designed to improve livestock productivity, health and for methane mitigation strategies from cattle. Although rumen microbial communities have been studied previously, few studies have applied next-generation sequencing technologies to that ecosystem. The aim of this study was to characterize changes in microbial community structure arising from feeding dairy cows two widely used diets: pasture and total mixed ration (TMR). Bacterial, archaeal and protozoal communities were characterized by terminal restriction fragment length polymorphism of the amplified SSU rRNA gene and statistical analysis showed that bacterial and archaeal communities were significantly affected by diet, whereas no effect was observed for the protozoal community. Deep amplicon sequencing of the 16S rRNA gene revealed significant differences in the bacterial communities between the diets and between rumen solid and liquid content. At the family level, some important groups of rumen bacteria were clearly associated with specific diets, including the higher abundance of the Fibrobacteraceae in TMR solid samples and members of the propionate-producing Veillonelaceae in pasture samples. This study will be relevant to the study of rumen microbial ecology and livestock feed management. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Bacterioplankton assemblages in coastal ponds reflect the influence of hydrology and geomorphological setting.

PubMed

Huggett, Megan J; Kavazos, Christopher R J; Bernasconi, Rachele; Czarnik, Robert; Horwitz, Pierre

2017-06-01

The factors that shape microbial community assembly in aquatic ecosystems have been widely studied; yet it is still unclear how distinct communities within a connected landscape influence one another. Coastal lakes are recipients of, and thus are connected to, both marine and terrestrial environments. Thus, they may host microbial assemblages that reflect the relative degree of influence by, and connectivity to, either system. In order to address this idea, we interrogated microbial community diversity at 49 sites in seven ponds in two seasons in the Lake MacLeod basin, a system fed by seawater flowing inland through underground karst. Environmental and spatial variation within ponds explain <9% of the community structure, while identity of the pond that samples were taken from explains 50% of community variation. That is, ponds each host distinct assemblages despite similarities in size, environment and position in the landscape, indicating a dominant role for local species sorting. The ponds contain a substantial amount of previously unknown microbial taxa, reflecting the unusual nature of this inland system. Rare marine taxa, possibly dispersed from seawater assemblages via the underground karst connection, are abundant within the inland system, suggesting an important role for regional dispersal within the metacommunities. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Japanese traditional dietary fungus koji Aspergillus oryzae functions as a prebiotic for Blautia coccoides through glycosylceramide: Japanese dietary fungus koji is a new prebiotic.

PubMed

Hamajima, Hiroshi; Matsunaga, Haruka; Fujikawa, Ayami; Sato, Tomoya; Mitsutake, Susumu; Yanagita, Teruyoshi; Nagao, Koji; Nakayama, Jiro; Kitagaki, Hiroshi

2016-01-01

The Japanese traditional cuisine, Washoku, considered to be responsible for increased longevity among the Japanese, comprises various foods fermented with the non-pathogenic fungus Aspergillus oryzae (koji). We have recently revealed that koji contains an abundant amount of glycosylceramide. Intestinal microbes have significant effect on health. However, the effects of koji glycosylceramide on intestinal microbes have not been studied. Glycosylceramide was extracted and purified from koji. C57BL/6N mice were fed a diet containing 1 % purified koji glycosylceramide for 1 week. Nutritional parameters and faecal lipid constituents were analyzed. The intestinal microbial flora of mice on this diet was investigated. Ingested koji glycosylceramide was neither digested by intestinal enzymes nor was it detected in the faeces, suggesting that koji glycosylceramide was digested by the intestinal microbial flora. Intestinal microbial flora that digested koji glycosylceramide had an increased ratio of Blautia coccoides. Stimulation of B. coccoides growth by pure koji glycosylceramide was confirmed in vitro. Koji functions as a prebiotic for B. coccoides through glycosylceramide. Since there are many reports of the effects of B. coccoides on health, an increase in intestinal B. coccoides by koji glycosylceramide might be the connection between Japanese cuisine, intestinal microbial flora, and longevity.

Molecular identification and nanoremediation of microbial contaminants in algal systems using untreated wastewater.

PubMed

Limayem, Alya; Gonzalez, Francisco; Micciche, Andrew; Haller, Edward; Nayak, Bina; Mohapatra, Shyam

2016-12-01

Wastewater-algal biomass is a promising option to biofuel production. However, microbial contaminants constitute a substantial barrier to algal biofuel yield. A series of algal strains, Nannochloris oculata and Chlorella vulgaris samples (n = 30), were purchased from the University of Texas, and were used for both stock flask cultures and flat-panel vertical bioreactors. A number of media were used for isolation and differentiation of potential contaminants according to laboratory standards (CLSI). Conventional PCR amplification was performed followed by 16S rDNA sequencing to identify isolates at the species level. Nanotherapeutics involving a nanomicellar combination of natural chitosan and zinc oxide (CZNPs) were tested against the microbial lytic groups through Minimum Inhibitory Concentration (MIC) tests and Transmission Electronic Microscopy (TEM). Results indicated the presence of Pseudomonas spp., Bacillus pumilus/ safensis, Cellulosimicrobium cellulans, Micrococcus luteus and Staphylococcus epidermidis strains at a substantial level in the wastewater-fed algal reactors. TEM confirmed the effectiveness of CZNPs on the lytic group while the average MICs (mg/mL) detected for the strains, Pseudomonas spp, Micrococcus luteus, and Bacillus pumilus were 0.417, 3.33, and 1.458, respectively. Conclusively, CZNP antimicrobials proved to be effective as inhibitory agents against currently identified lytic microbial group, did not impact algae cells, and shows promise for in situ interventions.

The Escherichia coli O157:H7 bovine rumen fluid proteome reflects adaptive bacterial responses.

PubMed

Kudva, Indira T; Stanton, Thaddeus B; Lippolis, John D

2014-02-21

To obtain insights into Escherichia coli O157:H7 (O157) survival mechanisms in the bovine rumen, we defined the growth characteristics and proteome of O157 cultured in rumen fluid (RF; pH 6.0-7.2 and low volatile fatty acid content) obtained from rumen-fistulated cattle fed low protein content "maintenance diet" under diverse in vitro conditions. Bottom-up proteomics (LC-MS/MS) of whole cell-lysates of O157 cultured under anaerobic conditions in filter-sterilized RF (fRF; devoid of normal ruminal microbiota) and nutrient-depleted and filtered RF (dRF) resulted in an anaerobic O157 fRF-and dRF-proteome comprising 35 proteins functionally associated with cell structure, motility, transport, metabolism and regulation, but interestingly, not with O157 virulence. Shotgun proteomics-based analysis using isobaric tags for relative and absolute quantitation used to further study differential protein expression in unfiltered RF (uRF; RF containing normal rumen microbial flora) complemented these results. Our results indicate that in the rumen, the first anatomical compartment encountered by this human pathogen within the cattle gastrointestinal tract (GIT), O157 initiates a program of specific gene expression that enables it to adapt to the in vivo environment, and successfully transit to its colonization sites in the bovine GIT. Further experiments in vitro using uRF from animals fed different diets and with additional O157 strains, and in vivo using rumen-fistulated cattle will provide a comprehensive understanding of the adaptive mechanisms involved, and help direct evolution of novel modalities for blocking O157 infection of cattle.

Phytogenic Feed Additives as an Alternative to Antibiotic Growth Promoters in Broiler Chickens

PubMed Central

Murugesan, Ganapathi Raj; Syed, Basharat; Haldar, Sudipto; Pender, Chasity

2015-01-01

The recent trend toward reduction of antibiotic growth promoters (AGP) in North American poultry diets has put tremendous pressure on the industry to look for viable alternatives. In this context, phytogenic feed additives (PFA) are researched to improve gut health and thereby performance. An experiment was conducted with the objective to evaluate the effects of PFA as an alternative to AGP on small intestinal histomorphology, cecal microbiota composition, nutrient digestibility, and growth performance in broiler chickens. A total of 432-day-old Vencobb 400 broiler chicks were randomly assigned to one of three dietary groups, each consisting of 12 replicate pens (n = 12 chicks/pen). The chicks were fed a corn–soybean meal-based control (CON), CON + 500 mg/kg of AGP (bacitracin methylene disalicylate containing 450 mg active BMD/g), or CON + 150 mg/kg of proprietary blend of PFA (Digestarom® Poultry) until 39 days of age when samples were collected. Birds fed either AGP or PFA had increased villus height in all three segments of the small intestine in comparison to the birds fed CON (P ≤ 0.05). Furthermore, the PFA-fed birds had significantly increased villus height and lower crypt depth compared to AGP fed birds (P ≤ 0.05). Birds fed either additive also had increased total tract digestibility of dry matter, crude protein, and ether extract (P ≤ 0.05). The strong effect of the PFA on villus height in the jejunum may suggest augmented nutrient absorption in PFA-fed birds. Although both additives reduced total cecal counts of anaerobic bacteria and Clostridium spp., PFA alone reduced the total coliform count while increasing the Lactobacillus spp. count (P ≤ 0.05). These results suggest the establishment of beneficial microbial colonies in PFA-fed birds. Overall, both PFA and AGP increased body weight gain while lowering the feed conversion ratio (P ≤ 0.05). Hence data from this experiment demonstrate the efficacy of PFA as a substitute to AGP in poultry diets. PMID:26664950

Effect of protein supplementation on ruminal parameters and microbial community fingerprint of Nellore steers fed tropical forages.

PubMed

Bento, C B P; Azevedo, A C; Gomes, D I; Batista, E D; Rufino, L M A; Detmann, E; Mantovani, H C

2016-01-01

In tropical regions, protein supplementation is a common practice in dairy and beef farming. However, the effect of highly degradable protein in ruminal fermentation and microbial community composition has not yet been investigated in a systematic manner. In this work, we aimed to investigate the impact of casein supplementation on volatile fatty acids (VFA) production, specific activity of deamination (SAD), ammonia concentration and bacterial and archaeal community composition. The experimental design was a 4×4 Latin square balanced for residual effects, with four animals (average initial weight of 280±10 kg) and four experimental periods, each with duration of 29 days. The diet comprised Tifton 85 (Cynodon sp.) hay with an average CP content of 9.8%, on a dry matter basis. Animals received basal forage (control) or infusions of pure casein (230 g) administered direct into the rumen, abomasum or divided (50 : 50 ratio) in the rumen/abomasum. There was no differences (P>0.05) in ruminal pH and microbial protein concentration between supplemented v. non-supplemented animals. However, in steers receiving ruminal infusion of casein the SAD and ruminal ammonia concentration increased 33% and 76%, respectively, compared with the control. The total concentration of VFA increased (P0.05) in species richness and diversity of γ-proteobacteria, firmicutes and archaea between non-supplemented Nellore steers and steers receiving casein supplementation in the rumen. However, species richness and the Shannon-Wiener index were lower (P<0.05) for the phylum bacteroidetes in steers supplemented with casein in the rumen compared with non-supplemented animals. Venn diagrams indicated that the number of unique bands varied considerably among individual animals and was usually higher in number for non-supplemented steers compared with supplemented animals. These results add new knowledge about the effects of ruminal and postruminal protein supplementation on metabolic activities of rumen microbes and the composition of bacterial and archaeal communities in the rumen of steers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

In this study, furanic and phenolic compounds are problematic byproducts resulting from the decomposition of lignocellulosic biomass during biofuel production. This study assessed the capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H 2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the sole carbon and energy source in the bioanode. The rate and extent of biotransformation of the five compounds, efficiency of H 2 production, as well as the anode microbial community structure were investigated. The five compoundsmore » were completely transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1,200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode coulombic efficiency was 44-69%, which is comparable to wastewater-fed MECs. The H 2 yield varied from 0.26 to 0.42 g H 2-COD/g COD removed in the anode, and the bioanode volume-normalized H 2 production rate was 0.07-0.1 L/L-d. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H 2 production were inhibited at an initial substrate concentration of 1,200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The H 2 production route demonstrated in this study has proven to be an alternative to the currently used process of reforming natural gas to supply H 2 needed to upgrade bio-oils to stable hydrocarbon fuels.« less

Influence of ruminal or duodenal soybean oil infusion on intake, ruminal fermentation, site and extent of digestion, and microbial protein synthesis in beef heifers consuming grass hay.

PubMed

Krysl, L J; Judkins, M B; Bohman, V R

1991-06-01

Six heifers (two Hereford X Jersey, four Hereford X Longhorn; average BW 278 kg) cannulated at the rumen and duodenum and fed a grass hay (fescue/orchardgrass) diet were used in a replicated 3 X 3 Latin square. Treatments were either no infusion (C), 150 ml of duodenally infused soybean oil (DI), or 150 ml of ruminally infused soybean oil (RI)/heifer twice daily for a total daily infusion of 300 ml of soybean oil. Periods of the Latin square included 18 d for adaptation and 5 d for collection. Forage OM, ADF, NDF, and N intakes were not affected (P greater than .10) by soybean oil infusion. Ruminal (P = .11) and total tract (P less than .10) OM digestibilities were decreased by RI compared with C or DI, but ADF and NDF digestibilities were not affected by treatment. Duodenal N (P less than .05) and microbial N flows were increased (P less than .10) for C and RI compared with DI. Microbial efficiency (g of N/kg of OM truly fermented) was improved (P less than .10) by RI compared with DI but did not differ (P greater than .10) from C. Ruminal pH was lower (P less than .05) with RI than with either C or DI. Ruminal NH3 N, total VFA, and acetate were not affected (P greater than .10) by treatment. Propionate (mol/100 mol) was greater (P less than .05) with RI than with DI and C, but the proportion of butyrate did not differ among treatments. These data indicate minimal direct benefits for improving forage usage as a result of soybean oil infusion with a 100% grass diet; however, animals should realize benefits from additional dietary energy provided by infused lipid.

Application of enzymatic apple pomace hydrolysate to production of 2,3-butanediol by alkaliphilic Bacillus licheniformis NCIMB 8059.

PubMed

Białkowska, Aneta M; Gromek, Ewa; Krysiak, Joanna; Sikora, Barbara; Kalinowska, Halina; Jędrzejczak-Krzepkowska, Marzena; Kubik, Celina; Lang, Siegmund; Schütt, Fokko; Turkiewicz, Marianna

2015-12-01

2,3-Butanediol (2,3-BD) synthesis by a nonpathogenic bacterium Bacillus licheniformis NCIMB 8059 from enzymatic hydrolysate of depectinized apple pomace and its blend with glucose was studied. In shake flasks, the maximum diol concentration in fed-batch fermentations was 113 g/L (in 163 h, from the hydrolysate, feedings with glucose) while in batch processes it was around 27 g/L (in 32 h, from the hydrolysate and glucose blend). Fed-batch fermentations in the 0.75 and 30 L fermenters yielded 87.71 g/L 2,3-BD in 160 h, and 72.39 g/L 2,3-BD in 94 h, respectively (from the hydrolysate and glucose blend, feedings with glucose). The hydrolysate of apple pomace, which was for the first time used for microbial 2,3-BD production is not only a source of sugars but also essential minerals.

Influence of ultrasonication on anaerobic bioconversion of sludge.

PubMed

Mao, Taohong; Show, Kuan-Yeow

2007-04-01

The influence of ultrasonication on hydrolysis, acidogenesis, and methanogenesis in anaerobic decomposition of sludge was investigated. The sonicated sludge exhibited prehydrolysis and preacidogenesis effects in the anaerobic decomposition process. First-order hydrolysis rates increased from 0.0384 day(-1) in the control digester to 0.0672 day(-1) in the digester fed, with sludge sonicated at 0.52 W/mL. The sonication appeared to be ineffective in relation to acidogenesis reaction rates, but it provided a better buffering capacity to diminish the adverse effect of acidification. Digesters fed with sonicated sludge demonstrated enhanced methanogenesis over the control unit. Determination by coenzyme F420 verified that sonication is able to promote the growth of methanogenic biomass and facilitate a positive methanogenic microbial development in suppressing the initial methanogenesis limitation. The results suggest that ultrasonication could enhance anaerobic decomposition of sludge, resulting in an accelerated bioconversion, improved organics degradation, improved biogas production, and increased methane content.

Carbon-Based Nanomaterials in Biomass-Based Fuel-Fed Fuel Cells

PubMed Central

Vestergaard, Mun’delanji C.; Tamiya, Eiichi

2017-01-01

Environmental and sustainable economical concerns are generating a growing interest in biofuels predominantly produced from biomass. It would be ideal if an energy conversion device could directly extract energy from a sustainable energy resource such as biomass. Unfortunately, up to now, such a direct conversion device produces insufficient power to meet the demand of practical applications. To realize the future of biofuel-fed fuel cells as a green energy conversion device, efforts have been devoted to the development of carbon-based nanomaterials with tunable electronic and surface characteristics to act as efficient metal-free electrocatalysts and/or as supporting matrix for metal-based electrocatalysts. We present here a mini review on the recent advances in carbon-based catalysts for each type of biofuel-fed/biofuel cells that directly/indirectly extract energy from biomass resources, and discuss the challenges and perspectives in this developing field. PMID:29125564

Carbon-Based Nanomaterials in Biomass-Based Fuel-Fed Fuel Cells.

PubMed

Hoa, Le Quynh; Vestergaard, Mun'delanji C; Tamiya, Eiichi

2017-11-10

Environmental and sustainable economical concerns are generating a growing interest in biofuels predominantly produced from biomass. It would be ideal if an energy conversion device could directly extract energy from a sustainable energy resource such as biomass. Unfortunately, up to now, such a direct conversion device produces insufficient power to meet the demand of practical applications. To realize the future of biofuel-fed fuel cells as a green energy conversion device, efforts have been devoted to the development of carbon-based nanomaterials with tunable electronic and surface characteristics to act as efficient metal-free electrocatalysts and/or as supporting matrix for metal-based electrocatalysts. We present here a mini review on the recent advances in carbon-based catalysts for each type of biofuel-fed/biofuel cells that directly/indirectly extract energy from biomass resources, and discuss the challenges and perspectives in this developing field.

Ration formulations containing reduced-fat dried distillers grains with solubles and their effect on lactation performance, rumen fermentation, and intestinal flow of microbial nitrogen in Holstein cows.

PubMed

Castillo-Lopez, E; Ramirez Ramirez, H A; Klopfenstein, T J; Hostetler, D; Karges, K; Fernando, S C; Kononoff, P J

2014-03-01

Sixteen multiparous lactating Holstein cows were used in 2 experiments to evaluate the effects of reduced-fat dried distillers grains with solubles (RFDG) on milk production, rumen fermentation, intestinal microbial N flow, and total-tract nutrient digestibility. In experiment 1, RFDG was fed at 0, 10, 20, or 30% of diet dry matter (DM) to 12 noncannulated Holstein cows (mean ± standard deviation: 89 ± 11 d in milk and 674 ± 68.2 kg of body weight) to determine effects on milk production. In experiment 2, the same diets were fed to 4 ruminally and duodenally cannulated Holstein cows (mean ± standard deviation: 112 ± 41 d in milk; 590 ± 61.14 kg of body weight) to evaluate the effects on rumen fermentation, intestinal flow of microbial N, and total-tract nutrient digestibility. In both experiments, cows were randomly assigned to 4 × 4 Latin squares over 21-d periods. Treatments (DM basis) were (1) control (0% RFDG), (2) 10% RFDG, (3) 20% RFDG, and (4) 30% RFDG. Feed intake and milk yield were recorded daily. In both experiments, milk samples were collected on d 19 to 21 of each period for analysis of milk components. In experiment 2, ruminal pH was measured; samples of rumen fluid, duodenal digesta, and feces were collected on d 18 to 21. Microbial N was estimated by using purines and DNA as microbial markers. Milk yield was not affected by treatment and averaged 34.0 ± 1.29 kg/d and 31.4 ± 2.81 kg/d in experiments 1 and 2, respectively. Percentage of milk protein tended to increase in experiment 1; estimates were 3.08, 3.18, 3.15, and 3.19 ± 0.06% when RFDG increased from 0 to 30% in the diets. However, milk protein concentration was not affected in experiment 2 and averaged 3.02 ± 0.07%. Percentage of milk fat was not affected and averaged 3.66 ± 0.05% and 3.25 ± 0.14% in experiments 1 and 2, respectively. Total ruminal volatile fatty acids and ammonia concentrations were not affected by treatment and averaged 135.18 ± 6.45 mM and 18.66 ± 2.32 mg/dL, respectively. Intestinal microbial N flow was not affected by treatment; however, purines yielded higher estimates of flow compared with DNA markers. When averaged across treatments, intestinal flow of microbial N was 303 and 218 ± 18 g of N/d, using purines and DNA as the markers. Dry matter, organic matter, neutral detergent fiber, and nonfiber carbohydrate digestibility tended to increase with increasing inclusion of RFDG. Results from these experiments indicate that dairy rations can be formulated to include up to 30% RFDG while maintaining lactation performance, volatile fatty acids concentration, and intestinal supply of microbial N. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Identification of novel potential acetate-oxidizing bacteria in an acetate-fed methanogenic chemostat based on DNA stable isotope probing.

PubMed

Wang, Hui-Zhong; Gou, Min; Yi, Yue; Xia, Zi-Yuan; Tang, Yue-Qin

2018-05-11

Acetate is a significant intermediate of anaerobic fermentation. There are two pathways for converting acetate to CH 4 and CO 2 : acetoclastic methanogenesis by acetoclastic methanogens, and syntrophic acetate oxidation by acetate-oxidizing bacteria (AOB) and hydrogenotrophic methanogens. Detailed investigations of syntrophic acetate-oxidizing bacteria (SAOB) should contribute to the elucidation of the microbial mechanisms of methanogenesis. In this study, we investigated the major phylogenetic groups of acetate-utilizing bacteria (AUB) in a mesophilic methanogenic chemostat fed with acetate as the sole carbon source by using DNA stable isotope probing (SIP) technology. The results indicated that acetoclastic methanogenesis and acetate oxidization/hydrogenotrophic methanogenesis coexisted in the mesophilic chemostat fed with acetate, operated at a dilution rate of 0.1 d -1 . OTU Ace13(9-17) (KU869530), Ace13(9-4) (KU667241), and Ace13(9-23) (KU667236), assigned to the phyla Firmicutes and Bacteroidetes, were probably potential SAOB in the chemostat, which needs further investigation. Species in the phyla Proteobacteria, Deferribacteres, Acidobacteria, Spirochaetes and Actinobacteria were probably capable of utilizing acetate for their growth. Methanoculleus was likely to be the preferred hydrogenotrophic methanogen for syntrophy with AOB in the chemostat.

Rapid biodegradation of plastics by mealworms (larvae of Tenebrio molitor) brings hope to solve wasteplastic pollution

NASA Astrophysics Data System (ADS)

Wu, W.; Yang, S.; Brandon, A. M.; Yang, Y.; Flanagan, J. A.; Fan, H. Q.; Cai, S. Y.; Wang, Z. Y.; Din, L. Y.; Daliang, N.; Yang, J.; Ren, J.; Tao, H. C.; Phillips, D.; Ren, N. Q.; Zhou, J.; Waymouth, R.; Criddle, C. S.

2016-12-01

Pollution of waste plastics in soil, river, ocean, landfill and potentially groundwater has been a major environment concern for decades. They include polystyrene (PS), polyethylene (PE) and others. Plastic particles could penetrate into groundwater and become potential threats to our groundwater Our recent research demonstrated that mealworm (larvae of Tenebrio molitor ), which are commercially used as animal and bird food and insect protein, can biodegrade PS and convert it to CO2 up within 48% within 12-14 hrs in mealworm gut. PS degradation was performed initially via depolymerization and then degradation within the mealworm guts. Gut microbiota plays a major role in PS biodegradation because the degradation is nearly completely inhibited when mealworms were fed with antibiotics. Physical and chemical analysis as well 13C labeled tests confirmed the biodegradation and mineralization of PS. The generality of plastic eating behavior of mealworms and biodegradation has been observed by testing mealworms from 11 different sources in China and the USA. All of the mealworms tested consume PS although at different relative rates. At ambient temperature (20-24 oC), the average daily consumption rate of PS ranged from 0.01 to 0.3 mg per 100 mealworms when fed PS alone. The mealworms also consumed low density polyethylene (LDPE) foam as sole diet. When mealworms were fed PS alone, the consumption rate and total amount consumed increased slightly as a function of temperature from 20 to 30 oC. Supplementing the diet with normal food (bran) enhanced the PS consumption rate and the total PS mass consumed. Microbial community analysis indicated that the microbial structure changed significantly after the diet was switched from normal food bran to PS or PS plus bran. PS-degrading bacterial strains have isolated and characterized. Our discoveries brings hopes to prevent or solve potential microplastics threats to groundwater.

Performance evaluation of a continuous-flow bioanode microbial electrolysis cell fed with furanic and phenolic compounds

DOE PAGES

Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

2016-07-04

Furanic and phenolic compounds, formed during the pretreatment of lignocellulosic biomass, are problematic byproducts in down-stream biofuel processes. A microbial electrolysis cell (MEC) is an alternative technology to handle furanic and phenolic compounds and produce renewable hydrogen (H 2). In this study, we evaluated the performance of a continuous-flow bioanode MEC fed with furanic and phenolic compounds at different operating conditions. All hydraulic retention times (HRTs) tested (6-24 h) resulted in complete transformation of the parent compounds at an organic loading rate (OLR) of 0.2g L -1 per d and applied voltage of 0.6 V. Increasing the OLR to 0.8more » g L -1 per d at an HRT of 6h resulted in an increased H 2 production rate from 0.07 to 0.14 L L anode 1 per d, but an OLR of 3.2 g L -1 per d did not lead to a higher H 2 production rate. Significant methane production was observed at an OLR of 3.2 g L -1 per d. The lack of increased H 2 production at the highest OLR tested was due to a limited rate of exoelectrogenesis but not fermentation, evidenced by the accumulation of high acetate levels and higher growth of fermenters and methanogens over exoelectrogens. Increasing applied voltage from 0.6 to 1.0V at an OLR of 3.2 g L -1 per d and HRT of 6h enhanced exoelectrogenesis and resulted in a 1.7-fold increase of H 2 production. Under all operating conditions, more than 90% of the biomass was biofilm-associated. Lastly, the present study provides new insights into the performance of continuous-flow bioelectrochemical systems fed with complex waste streams resulting from the pretreatment of lignocellulosic biomass.« less

Sugarcane bagasse as exclusive roughage for dairy cows in smallholder livestock system.

PubMed

de Almeida, Gleidiana Amélia Pontes; de Andrade Ferreira, Marcelo; de Lima Silva, Janaina; Chagas, Juana Catarina Cariri; Véras, Antônia Sherlânea Chaves; de Barros, Leonardo José Assis; de Almeida, Gledson Luiz Pontes

2018-03-01

The study aimed to evaluate sugarcane bagasse as roughage in lactating cow on feed intake, digestibility, ingestive behavior, milk production and composition, and microbial protein synthesis. Ten Girolando cows at initial body weight of 450±25.6 kg and at 143.7±30.7 days in milk were assigned in two 5×5 Latin square designs. Five 21-day experimental periods were adopted (1° to 14-day: diets adaptation period; 15° to 21-day: data collection and sampling period). The diets consisted of four different levels of sugarcane bagasse (45%, 50%, 55%, and 60%) and a control diet, commonly adopted in the region, based on spineless cactus (25% sugarcane bagasse), formulated to meet 12 kg/d milk yield. The dry matter (DM), organic matter (OM), and total digestible nutrients intakes and DM and OM digestibilities observed for 45% and 50% bagasse inclusion were similar to control diet, while that 55% and 60% bagasse inclusion were lower. Cows fed control diet, and bagasse diets of 45%, and 50% levels had the nutritional requirements attended, that guaranteed 12 kg/d of milk yield. The crude protein intake and digestibility of cows fed 45%, 50%, and 55% of bagasse inclusion were similar to control diet. The neutral detergent fiber (NDF) intake and digestibility differ for all bagasse diets related to control diet, while the non-fiber carbohydrates intake and digestibility for cows fed 45% of bagasse were similar for control diet. The intakes and digestibilities of nutrients decreased linearly in function of bagasse inclusion; NDF and indigestible NDF intakes did not vary. The ruminating time, feeding and rumination efficiency, microbial protein synthesis and milk yield decreased linearly with sugarcane bagasse inclusion. Sugarcane bagasse decreases milk production; however, its inclusion level in between 45% to 50% associated to concentrate could replace diets based on spineless cactus for crossbred dairy cow's producing 12 kg/d of milk.

Sugarcane bagasse as exclusive roughage for dairy cows in smallholder livestock system

PubMed Central

2018-01-01

Objective The study aimed to evaluate sugarcane bagasse as roughage in lactating cow on feed intake, digestibility, ingestive behavior, milk production and composition, and microbial protein synthesis. Methods Ten Girolando cows at initial body weight of 450±25.6 kg and at 143.7±30.7 days in milk were assigned in two 5×5 Latin square designs. Five 21-day experimental periods were adopted (1° to 14-day: diets adaptation period; 15° to 21-day: data collection and sampling period). The diets consisted of four different levels of sugarcane bagasse (45%, 50%, 55%, and 60%) and a control diet, commonly adopted in the region, based on spineless cactus (25% sugarcane bagasse), formulated to meet 12 kg/d milk yield. Results The dry matter (DM), organic matter (OM), and total digestible nutrients intakes and DM and OM digestibilities observed for 45% and 50% bagasse inclusion were similar to control diet, while that 55% and 60% bagasse inclusion were lower. Cows fed control diet, and bagasse diets of 45%, and 50% levels had the nutritional requirements attended, that guaranteed 12 kg/d of milk yield. The crude protein intake and digestibility of cows fed 45%, 50%, and 55% of bagasse inclusion were similar to control diet. The neutral detergent fiber (NDF) intake and digestibility differ for all bagasse diets related to control diet, while the non-fiber carbohydrates intake and digestibility for cows fed 45% of bagasse were similar for control diet. The intakes and digestibilities of nutrients decreased linearly in function of bagasse inclusion; NDF and indigestible NDF intakes did not vary. The ruminating time, feeding and rumination efficiency, microbial protein synthesis and milk yield decreased linearly with sugarcane bagasse inclusion. Conclusion Sugarcane bagasse decreases milk production; however, its inclusion level in between 45% to 50% associated to concentrate could replace diets based on spineless cactus for crossbred dairy cow's producing 12 kg/d of milk. PMID:29059720

Enhancement of electricity production by graphene oxide in soil microbial fuel cells and plant microbial fuel cells.

PubMed

Goto, Yuko; Yoshida, Naoko; Umeyama, Yuto; Yamada, Takeshi; Tero, Ryugo; Hiraishi, Akira

2015-01-01

The effects of graphene oxide (GO) on electricity generation in soil microbial fuel cells (SMFCs) and plant microbial fuel cell (PMFCs) were investigated. GO at concentrations ranging from 0 to 1.9 g⋅kg(-1) was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs) utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity generation in GO-SMFCs containing 1.0 g⋅kg(-1) of GO was 40 ± 19 mW⋅m(-2), which was significantly higher than the value of 6.6 ± 8.9 mW⋅m(-2) generated from GO-free SMFCs (p < 0.05). The increase in catalytic current at the oxidative potential was observed by cyclic voltammetry (CV) for GO-SMFC, with the CV curve suggesting the enhancement of electron transfer from oxidation of organic substances in the soil by the reduced form of GO. The GO-containing PMFC also displayed a greater generation of electricity compared to the PMFC with no added GO, with GO-PMFC producing 49 mW⋅m(-2) of electricity after 27 days of operation. Collectively, this study demonstrates that GO added to soil can be microbially reduced in soil, and facilitates electron transfer to the anode in both SMFCs and PMFCs.

Enhancement of Electricity Production by Graphene Oxide in Soil Microbial Fuel Cells and Plant Microbial Fuel Cells

PubMed Central

Goto, Yuko; Yoshida, Naoko; Umeyama, Yuto; Yamada, Takeshi; Tero, Ryugo; Hiraishi, Akira

2015-01-01

The effects of graphene oxide (GO) on electricity generation in soil microbial fuel cells (SMFCs) and plant microbial fuel cell (PMFCs) were investigated. GO at concentrations ranging from 0 to 1.9 g⋅kg−1 was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs) utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity generation in GO-SMFCs containing 1.0 g⋅kg−1 of GO was 40 ± 19 mW⋅m−2, which was significantly higher than the value of 6.6 ± 8.9 mW⋅m−2 generated from GO-free SMFCs (p < 0.05). The increase in catalytic current at the oxidative potential was observed by cyclic voltammetry (CV) for GO-SMFC, with the CV curve suggesting the enhancement of electron transfer from oxidation of organic substances in the soil by the reduced form of GO. The GO-containing PMFC also displayed a greater generation of electricity compared to the PMFC with no added GO, with GO-PMFC producing 49 mW⋅m−2 of electricity after 27 days of operation. Collectively, this study demonstrates that GO added to soil can be microbially reduced in soil, and facilitates electron transfer to the anode in both SMFCs and PMFCs. PMID:25883931

Microbial population and functional dynamics associated with surface potential and carbon metabolism

PubMed Central

Ishii, Shun'ichi; Suzuki, Shino; Norden-Krichmar, Trina M; Phan, Tony; Wanger, Greg; Nealson, Kenneth H; Sekiguchi, Yuji; Gorby, Yuri A; Bretschger, Orianna

2014-01-01

Microbial extracellular electron transfer (EET) to solid surfaces is an important reaction for metal reduction occurring in various anoxic environments. However, it is challenging to accurately characterize EET-active microbial communities and each member's contribution to EET reactions because of changes in composition and concentrations of electron donors and solid-phase acceptors. Here, we used bioelectrochemical systems to systematically evaluate the synergistic effects of carbon source and surface redox potential on EET-active microbial community development, metabolic networks and overall electron transfer rates. The results indicate that faster biocatalytic rates were observed under electropositive electrode surface potential conditions, and under fatty acid-fed conditions. Temporal 16S rRNA-based microbial community analyses showed that Geobacter phylotypes were highly diverse and apparently dependent on surface potentials. The well-known electrogenic microbes affiliated with the Geobacter metallireducens clade were associated with lower surface potentials and less current generation, whereas Geobacter subsurface clades 1 and 2 were associated with higher surface potentials and greater current generation. An association was also observed between specific fermentative phylotypes and Geobacter phylotypes at specific surface potentials. When sugars were present, Tolumonas and Aeromonas phylotypes were preferentially associated with lower surface potentials, whereas Lactococcus phylotypes were found to be closely associated with Geobacter subsurface clades 1 and 2 phylotypes under higher surface potential conditions. Collectively, these results suggest that surface potentials provide a strong selective pressure, at the species and strain level, for both solid surface respirators and fermentative microbes throughout the EET-active community development. PMID:24351938

Deposition and postdeposition mechanisms as possible drivers of microbial population variability in glacier ice.

PubMed

Xiang, Shu-Rong; Shang, Tian-Cui; Chen, Yong; Yao, Tan-Dong

2009-11-01

Glaciers accumulate airborne microorganisms year by year and thus are good archives of microbial communities and their relationship to climatic and environmental changes. Hypotheses have focused on two possible drivers of microbial community composition in glacier systems. One is aeolian deposition, in which the microbial load by aerosol, dust, and precipitation events directly determines the amount and composition of microbial species in glacier ice. The other is postdepositional selection, in which the metabolic activity in surface snow causes microbial community shifts in glacier ice. An additional possibility is that both processes occur simultaneously. Aeolian deposition initially establishes a microbial community in the ice, whereas postdeposition selection strengthens the deposition patterns of microorganisms with the development of tolerant species in surface snow, resulting in varying structures of microbial communities with depth. In this minireview, we examine these postulations through an analysis of physical-chemical and biological parameters from the Malan and Vostok ice cores, and the Kuytun 51 Glacial surface and deep snow. We discuss these and other recent results in the context of the hypothesized mechanisms driving microbial community succession in glaciers. We explore our current gaps in knowledge and point out future directions for research on microorganisms in glacial ecosystems.

Genome-Based Models to Optimize In Situ Bioremediation of Uranium and Harvesting Electrical Energy from Waste Organic Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lovley, Derek R

2012-12-28

The goal of this research was to provide computational tools to predictively model the behavior of two microbial communities of direct relevance to Department of Energy interests: 1) the microbial community responsible for in situ bioremediation of uranium in contaminated subsurface environments; and 2) the microbial community capable of harvesting electricity from waste organic matter and renewable biomass. During this project the concept of microbial electrosynthesis, a novel form of artificial photosynthesis for the direct production of fuels and other organic commodities from carbon dioxide and water was also developed and research was expanded into this area as well.

Production of electricity from acetate or butyrate using a single-chamber microbial fuel cell.

PubMed

Liu, Hong; Cheng, Shaoan; Logan, Bruce E

2005-01-15

Hydrogen can be recovered by fermentation of organic material rich in carbohydrates, but much of the organic matter remains in the form of acetate and butyrate. An alternative to methane production from this organic matter is the direct generation of electricity in a microbial fuel cell (MFC). Electricity generation using a single-chambered MFC was examined using acetate or butyrate. Power generated with acetate (800 mg/L) (506 mW/m2 or 12.7 mW/ L) was up to 66% higher than that fed with butyrate (1000 mg/L) (305 mW/m2 or 7.6 mW/L), demonstrating that acetate is a preferred aqueous substrate for electricity generation in MFCs. Power output as a function of substrate concentration was well described by saturation kinetics, although maximum power densities varied with the circuit load. Maximum power densities and half-saturation constants were Pmax = 661 mW/m2 and Ks = 141 mg/L for acetate (218 ohms) and Pmax = 349 mW/m2 and Ks = 93 mg/L for butyrate (1000 ohms). Similar open circuit potentials were obtained in using acetate (798 mV) or butyrate (795 mV). Current densities measured for stable power outputwere higher for acetate (2.2 A/m2) than those measured in MFCs using butyrate (0.77 A/m2). Cyclic voltammograms suggested that the main mechanism of power production in these batch tests was by direct transfer of electrons to the electrode by bacteria growing on the electrode and not by bacteria-produced mediators. Coulombic efficiencies and overall energy recovery were 10-31 and 3-7% for acetate and 8-15 and 2-5% for butyrate, indicating substantial electron and energy losses to processes other than electricity generation. These results demonstrate that electricity generation is possible from soluble fermentation end products such as acetate and butyrate, but energy recoveries should be increased to improve the overall process performance.

Combining Gal4p-mediated expression enhancement and directed evolution of isoprene synthase to improve isoprene production in Saccharomyces cerevisiae.

PubMed

Wang, Fan; Lv, Xiaomei; Xie, Wenping; Zhou, Pingping; Zhu, Yongqiang; Yao, Zhen; Yang, Chengcheng; Yang, Xiaohong; Ye, Lidan; Yu, Hongwei

2017-01-01

Current studies on microbial isoprene biosynthesis have mostly focused on regulation of the upstream mevalonic acid (MVA) or methyl-erythritol-4-phosphate (MEP) pathway. However, the downstream bottleneck restricting isoprene biosynthesis capacity caused by the weak expression and low activity of plant isoprene synthase (ISPS) under microbial fermentation conditions remains to be alleviated. Here, based on a previously constructed Saccharomyces cerevisiae strain with enhanced precursor supply, we strengthened the downstream pathway through increasing both the expression and activity of ISPS to further improve isoprene production. Firstly, a two-level expression enhancement system was developed for the P GAL1 -controlled ISPS by overexpression of GAL 4. Meanwhile, the native GAL1/7/10 promoters were deleted to avoid competition for the transcriptional activator Gal4p, and GAL80 was disrupted to eliminate the dependency of gene expression on galactose induction. The IspS expression was obviously elevated upon enhanced Gal4p supply, and the isoprene production was improved from 6.0mg/L to 23.6mg/L in sealed-vial cultures with sucrose as carbon source. Subsequently, a novel high-throughput screening method was developed based on precursor toxicity and used for ISPS directed evolution towards enhanced catalytic activity. Combinatorial mutagenesis of the resulting ISPS mutants generated the best mutant ISPSM4, introduction of which into the GAL4-overexpressing strain YXM29 achieved 50.2mg/L of isoprene in sealed vials, and the isoprene production reached 640mg/L and 3.7g/L in aerobic batch and fed-batch fermentations, respectively. These results demonstrated the effectiveness of the proposed combinatorial engineering strategy in isoprene biosynthesis, which might also be feasible and instructive for biotechnological production of other valuable chemicals. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Potential sources of hydrocarbons and their microbial degradation in sediments from the deep geothermal Lusi site, Indonesia

NASA Astrophysics Data System (ADS)

Krueger, Martin; Mazzini, Adriano; Scheeder, Georg; Blumenberg, Martin

2017-04-01

The Lusi eruption represents one of the largest ongoing sedimentary hosted geothermal systems, which started in 2006 following an earthquake on Java Island. Since then it has been continuously producing hot and hydrocarbon rich mud from a central crater with peaks reaching 180.000 m3 per day. Numerous investigations focused on the study of microbial communities which thrive at offshore methane and oil seeps and mud volcanoes, however very little has been done on onshore seeping structures. Lusi represents a unique opportunity to complete a comprehensive study of onshore microbial communities fed by the seepage of CH4 as well as of liquid hydrocarbons originating from one or more km below the surface. While the source of the methane at Lusi is unambiuous, the origin of the seeping oil is still discussed. Both, source and maturity estimates from biomarkers, are in favor of a type II/III organic matter source. Likely the oils were formed from the studied black shales (deeper Ngimbang Fm.) which contained a Type III component in the Type II predominated organic matter. In all samples large numbers of active microorganisms were present. Rates for aerobic methane oxidation were high, as was the potential of the microbial communities to degrade different hydrocarbons. The data suggests a transition of microbial populations from an anaerobic, hydrocarbon-driven metabolism in fresher samples from center or from small seeps to more generalistic, aerobic microbial communities in older, more consolidated sediments. Ongoing microbial activity in crater sediment samples under high temperatures (80-95C) indicate a deep origin of the involved microorganisms. First results of molecular analyses of the microbial community compositions confirm the above findings. This study represents an initial step to better understand onshore seepage systems and provides an ideal analogue for comparison with the better investigated offshore structures.

Host Age Affects the Development of Southern Catfish Gut Bacterial Community Divergent From That in the Food and Rearing Water.

PubMed

Zhang, Zhimin; Li, Dapeng; Refaey, Mohamed M; Xu, Weitong; Tang, Rong; Li, Li

2018-01-01

Host development influences gut microbial assemblies that may be confounded partly by dietary shifts and the changing environmental microbiota during ontogenesis. However, little is known about microbial colonization by excluding dietary effects and compositional differences in microbiota between the gut and environment at different ontogenetic stages. Herein, a developmental gut microbial experiment under controlled laboratory conditions was conducted with carnivorous southern catfish Silurus meridionalis fed on an identical prey with commensal and abundant microbiota. In this study, we provided a long-term analysis of gut microbiota associated with host age at 8, 18, 35, 65, and 125 day post-fertilization (dpf) and explored microbial relationships among host, food and water environment at 8, 35, and 125 dpf. The results showed that gut microbial diversity in southern catfish tended to increase linearly as host aged. Gut microbiota underwent significant temporal shifts despite similar microbial communities in food and rearing water during the host development and dramatically differed from the environmental microbiota. At the compositional abundance, Tenericute s and Fusobacteria were enriched in the gut and markedly varied with host age, whereas Spirochaetes and Bacteroidetes detected were persistently the most abundant phyla in food and water, respectively. In addition to alterations in individual microbial taxa, the individual differences in gut microbiota were at a lower level at the early stages than at the late stages and in which gut microbiota reached a stable status, suggesting the course of microbial successions. These results indicate that host development fundamentally shapes a key transition in microbial community structure, which is independent of dietary effects. In addition, the dominant taxa residing in the gut do not share their niche habitats with the abundant microbiota in the surrounding environment. It's inferred that complex gut microbiota could not be simple reflections of environmental microbiota. The knowledge enhances the understanding of gut microbial establishment in the developing fish and provides a useful resource for such studies of fish- or egg-associated microbiota in aquaculture.

The Promise of Microbial Technology.

ERIC Educational Resources Information Center

El Nawawy, Amin S.

1982-01-01

Prospects for microbial technology are discussed including: (1) possible transfer of nitrogen-fixing ability directly from bacteria to plant; (2) increasing food needs met through single-cell proteins and fermentation; (3) microbial production of antibiotics; and (4) increased biogas production. (Author/JN)

Extracellular Enzymes Facilitate Electron Uptake in Biocorrosion and Bioelectrosynthesis

PubMed Central

Deutzmann, Jörg S.; Sahin, Merve

2015-01-01

ABSTRACT Direct, mediator-free transfer of electrons between a microbial cell and a solid phase in its surrounding environment has been suggested to be a widespread and ecologically significant process. The high rates of microbial electron uptake observed during microbially influenced corrosion of iron [Fe(0)] and during microbial electrosynthesis have been considered support for a direct electron uptake in these microbial processes. However, the underlying molecular mechanisms of direct electron uptake are unknown. We investigated the electron uptake characteristics of the Fe(0)-corroding and electromethanogenic archaeon Methanococcus maripaludis and discovered that free, surface-associated redox enzymes, such as hydrogenases and presumably formate dehydrogenases, are sufficient to mediate an apparent direct electron uptake. In genetic and biochemical experiments, we showed that these enzymes, which are released from cells during routine culturing, catalyze the formation of H2 or formate when sorbed to an appropriate redox-active surface. These low-molecular-weight products are rapidly consumed by M. maripaludis cells when present, thereby preventing their accumulation to any appreciable or even detectable level. Rates of H2 and formate formation by cell-free spent culture medium were sufficient to explain the observed rates of methane formation from Fe(0) and cathode-derived electrons by wild-type M. maripaludis as well as by a mutant strain carrying deletions in all catabolic hydrogenases. Our data collectively show that cell-derived free enzymes can mimic direct extracellular electron transfer during Fe(0) corrosion and microbial electrosynthesis and may represent an ecologically important but so far overlooked mechanism in biological electron transfer. PMID:25900658

Linking microbial and ecosystem ecology using ecological stoichiometry: a synthesis of conceptual and empirical approaches

USGS Publications Warehouse

Hall, E.K.; Maixner, F.; Franklin, O.; Daims, H.; Richter, A.; Battin, T.

2011-01-01

Currently, one of the biggest challenges in microbial and ecosystem ecology is to develop conceptual models that organize the growing body of information on environmental microbiology into a clear mechanistic framework with a direct link to ecosystem processes. Doing so will enable development of testable hypotheses to better direct future research and increase understanding of key constraints on biogeochemical networks. Although the understanding of phenotypic and genotypic diversity of microorganisms in the environment is rapidly accumulating, how controls on microbial physiology ultimately affect biogeochemical fluxes remains poorly understood. We propose that insight into constraints on biogeochemical cycles can be achieved by a more rigorous evaluation of microbial community biomass composition within the context of ecological stoichiometry. Multiple recent studies have pointed to microbial biomass stoichiometry as an important determinant of when microorganisms retain or recycle mineral nutrients. We identify the relevant cellular components that most likely drive changes in microbial biomass stoichiometry by defining a conceptual model rooted in ecological stoichiometry. More importantly, we show how X-ray microanalysis (XRMA), nanoscale secondary ion mass spectroscopy (NanoSIMS), Raman microspectroscopy, and in situ hybridization techniques (for example, FISH) can be applied in concert to allow for direct empirical evaluation of the proposed conceptual framework. This approach links an important piece of the ecological literature, ecological stoichiometry, with the molecular front of the microbial revolution, in an attempt to provide new insight into how microbial physiology could constrain ecosystem processes.

Phytase supplementation increases bone mineral density, lean body mass and voluntary physical activity in rats fed a low-zinc diet.

PubMed

Scrimgeour, Angus G; Marchitelli, Louis J; Whicker, Jered S; Song, Yang; Ho, Emily; Young, Andrew J

2010-07-01

Phytic acid forms insoluble complexes with nutritionally essential minerals, including zinc (Zn). Animal studies show that addition of microbial phytase (P) to low-Zn diets improves Zn status and bone strength. The present study determined the effects of phytase supplementation on bone mineral density (BMD), body composition and voluntary running activity of male rats fed a high phytic acid, low-Zn diet. In a factorial design, rats were assigned to ZnLO (5 mg/kg diet), ZnLO+P (ZnLO diet with 1500 U phytase/kg) or ZnAD (30 mg/kg diet) groups and were divided into voluntary exercise (EX) or sedentary (SED) groups, for 9 weeks. SED rats were significantly heavier from the second week, and no catch-up growth occurred in EX rats. Feed intakes were not different between groups throughout the study. ZnLO animals had decreased food efficiency ratios compared to both phytase-supplemented (ZnLO+P) and Zn-adequate (ZnAD) animals (P<.01 compared to ZnLO). The ZnLO+P and ZnAD rats ran 56-75 km more total distance than ZnLO rats (P<.05), with the ZnLO+P rats running more kilometers per week than the ZnLO rats by Week 6. In vivo DEXA analyses indicate that rats fed phytase-supplemented diets had higher lean body mass (LBM) than those fed ZnLO diets; and that rats fed the Zn-adequate diets had the highest LBM. Body fat (%) was significantly lower in EX rats and was both Zn- and phytase insensitive. Rats fed phytase-supplemented diets had higher bone mineral content (BMC), bone area (BA) and BMD than rats fed ZnLO diets; and in rats fed ZnAD diets these indices were the highest. The dietary effects on BMC, BA and BMD were independent of activity level. We conclude that consuming supplemental dietary phytase or dietary Zn additively enhances Zn status to increase BMD, LBM and voluntary physical activity in rats fed a low-Zn diet. While the findings confirm that bone health is vulnerable to disruption by moderate Zn deficiency in rats, this new data suggests that if dietary Zn is limiting, supplemental phytase may have beneficial effects on LBM and performance activity. (c) 2010 Elsevier Inc. All rights reserved.

Effect of Scrophularia striata and Ferulago angulata, as alternatives to virginiamycin, on growth performance, intestinal microbial population, immune response, and blood constituents of broiler chickens.

PubMed

Rostami, Farhad; Ghasemi, Hossein A; Taherpour, Kamran

2015-09-01

An experiment was conducted to investigate the comparative effect of Scrophularia striata, Ferulago angulata, and virginiamycin (VM) on performance, intestinal microbial population, immune response, and blood constituents of broilers. A total of 300 Ross 308 male broiler chickens were randomly assigned to 5 treatments, with 5 replicates/treatment (10 chickens/pen). Birds were fed either a corn-soybean meal basal diet (control) or the basal diet supplemented with 200 mg/kg VM; 4 g/kg S. striata (SS1); 8 g/kg S. striata (SS2); 4 g/kg F. angulata (FA1); or 8 g/kg F. angulata (FA2). After 6 wk, the BW, ADG, and feed-to-gain ratio (F:G) of the VM, SS1, and FA1 groups were better (P<0.01) compared with the control group. At 42 d, cecal lactobacillus counts were higher (P=0.032) in SS2 and FA2 groups compared with the control and VM groups. In addition, broilers fed any of the diets exhibited lower coliform counts (P<0.05) in the ileum and ceca than those fed the control diet. Total and IgG antibody titers against SRBC for secondary responses, relative spleen weight, and lymphocyte counts were higher (P<0.05) in birds fed the SS2 or FA2 diet compared with the control group. Moreover, feeding the SS2 or FA2 diet decreased (P<0.05) the blood heterophil/lymphocyte ratio and plasma triglyceride level, whereas only the SS2 diet increased (P=0.037) the white blood cell counts compared with the control diet. All diets, except for the VM diet, decreased (P=0.009) the plasma cholesterol level compared to the control treatment. The plasma high-density lipoprotein cholesterol level was also increased (P=0.042) in the SS2 and FA2 groups. In conclusion, dietary S. striata or F. angulata at a level of 4 g/kg diet enhanced growth performance, which was comparable to that of VM used as an antibiotic growth promoter. Furthermore, a high dose of both herbs (8 g/kg diet) could beneficially affect the intestinal health and immune status of broilers. © 2015 Poultry Science Association Inc.