Sample records for propionic acid bacteria

  1. Effects of applying molasses, lactic acid bacteria and propionic acid on fermentation quality, aerobic stability and in vitro gas production of total mixed ration silage prepared with oat-common vetch intercrop on the Tibetan Plateau.

    PubMed

    Chen, Lei; Guo, Gang; Yuan, Xianjun; Zhang, Jie; Li, Junfeng; Shao, Tao

    2016-03-30

    The objective of this study was to investigate the effect of molasses, lactic acid bacteria and propionic acid on the fermentation quality, aerobic stability and in vitro gas production of total mixed ration (TMR) silage prepared with oat-common vetch intercrop on the Tibetan plateau. TMR (436 g kg(-1) dry matter (DM)) was ensiled with six experimental treatments: (1) no additives (control); (2) molasses (M); (3) an inoculant (Lactobacillus plantarum) (L); (4) propionic acid (P); (5) molasses + propionic acid (MP); (6) inoculant + propionic acid (LP). All silages were well preserved with low pH (< 4.19) and NH3-N contents, and high lactic acid contents after ensiling for 45 days. L and PL silages underwent a more efficient fermentation than silages without L. P and MP silages inhibited lactic acid production. Under aerobic conditions, M and L silage reduced aerobic stability for 15 and 74 h, respectively. All silages that had propionic acid in their treatments markedly (P < 0.05) improved the aerobic stability. After 72 h incubation, all additives treatments increased (P < 0.05) the 72 h cumulative gas production and in vitro DM digestibility (IVDMD) as compared with the control. L treatment decreased (P < 0.05) in vitro neutral detergent fibre degradability. Our findings show that TMR prepared with oat-common vetch intercrop can be well preserved. Although propionic acid is compatible with lactic acid bacteria, and when used together, they had minor effects on fermentation, aerobic stability and in vitro digestibility of TMR silage prepared with oat-common vetch intercrop. © 2015 Society of Chemical Industry.

  2. Metabolic interactions in methanogenic and sulfate-reducing bioreactors.

    PubMed

    Stams, A J M; Plugge, C M; de Bok, F A M; van Houten, B H G W; Lens, P; Dijkman, H; Weijma, J

    2005-01-01

    In environments where the amount of electron acceptors is insufficient for complete breakdown of organic matter, methane is formed as the major reduced end product. In such methanogenic environments organic acids are degraded by syntrophic consortia of acetogenic bacteria and methanogenic archaea. Hydrogen consumption by methanogens is essential for acetogenic bacteria to convert organic acids to acetate and hydrogen. Several syntrophic cocultures growing on propionate and butyrate have been described. These syntrophic fatty acid-degrading consortia are affected by the presence of sulfate. When sulfate is present sulfate-reducing bacteria compete with methanogenic archaea for hydrogen and acetate, and with acetogenic bacteria for propionate and butyrate. Sulfate-reducing bacteria easily outcompete methanogens for hydrogen, but the presence of acetate as carbon source may influence the outcome of the competition. By contrast, acetoclastic methanogens can compete reasonably well with acetate-degrading sulfate reducers. Sulfate-reducing bacteria grow much faster on propionate and butyrate than syntrophic consortia.

  3. Combined effects of organic acids and salt depending on type of acids and pathogens in laboratory media and acidified pickle.

    PubMed

    Bae, Y-M; Lee, S-Y

    2015-08-01

    In this study, the effectiveness of combining each of seven types of acids with 3% salt as a treatment against pathogens was investigated in laboratory media and acidified food. When 0.5% malic, 0.5% tartaric, 0.5% citric or 0.25% phosphoric acid was combined with 3% salt, there was a higher reduction in Gram-negative bacteria (Escherichia coli O157:H7 and Salmonella Typhimurium) compared to when using acid alone. However, when 0.5% acetic, 0.5% propionic or 0.25% lactic acid was combined with 3% salt, the salt provided protection against the acid treatment. However, the antagonistic effects of acetic, propionic and lactic acid seen with Gram-negative bacteria were not observed in Listeria monocytogenes. Antagonistic effects were similarly observed when E. coli O157:H7 was treated with acetic acid and salt in food. These results show that the addition of salt increases the resistance of Gram-negative bacteria to acid treatments when using acetic, propionic and lactic acid. This study shows that antagonistic effects were observed when Gram-negative bacteria were treated with organic acids of simple structure. It may provide useful information for understanding the acid resistance mechanism of Gram-negative bacteria and developing methods for preserving acidified food. © 2015 The Society for Applied Microbiology.

  4. Conversion of (Meth)acrylic acids to methane granular sludge: Initiation by specific anerobic microflora

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

    Shtarkman, N.B.; Obraztova, A.Y.; Laurinavichyus, K.S.

    1995-03-01

    The role of a specific anaerobic microflora in the initiation of degradation of (meth)acrylic acids to methane by granular sludge from a UASB reactor was investigated. Associations of anaerobic bacteria isolated from the anaerobic sludge, which was used for a long time for treatment of wastewater from (meth)acrylate production, were able to realize the initial stage of (meth)acrylic acid decomposition, i.e., a conversion of acrylic and methacrylic acids to propionic and isobutyric acids, respectively. When added to granules, these association played a role of an {open_quotes}initiator{close_quotes} of the degradation process, which was then continued by the granular sludge microflora utilizingmore » propionate and isobutyrate. Some characteristics of the granules adapted to propionate or isobutyrate are presented. The rates of propionate and isobutyrate consumption by adapted granules is, respectively, 21 and 53 times higher than the values obtained for nonadapted granules. A combined use of {open_quotes}initiating{close_quotes} bacteria and adapted granules provided degradation of (meth)acrylic acids with a maximum methane yield. The possibility is discussed of employing the granules, which are adapted to short-chain fatty acids, and the {open_quotes}initiating{close_quotes} bacteria, which accomplish the initial steps of the organic material decomposition to lower fatty acids, for the conversion of various chemical compounds to methane. 10 refs., 3 figs., 2 tabs.« less

  5. Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.

    PubMed

    Cibis, Katharina Gabriela; Gneipel, Armin; König, Helmut

    2016-02-20

    In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firmicutes, Tenericutes or Thermotogae. According to 16S rRNA gene sequences, most isolates were related to Clostridium sporosphaeroides, Defluviitoga tunisiensis and Dendrosporobacter quercicolus. Acetic, propionic or butyric acid were produced in cultures of isolates affiliated to Bacillus thermoamylovorans, Clostridium aminovalericum, Clostridium cochlearium/Clostridium tetani, C. sporosphaeroides, D. quercicolus, Proteiniborus ethanoligenes, Selenomonas bovis and Tepidanaerobacter sp. Isolates related to Thermoanaerobacterium thermosaccharolyticum produced acetic, butyric and lactic acid, and isolates related to D. tunisiensis formed acetic acid. Specific primer sets targeting 16S rRNA gene sequences were designed and used for real-time quantitative PCR (qPCR). The isolates were physiologically characterized and their role in BGP discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Influence of short-chain fatty acids on iron absorption by proximal colon.

    PubMed

    Bouglé, D; Vaghefi-Vaezzadeh, N; Roland, N; Bouvard, G; Arhan, P; Bureau, F; Neuville, D; Maubois, J L

    2002-09-01

    Short-chain fatty acids produced by bacterial fermentation in the colon enhance the local absorption of cations, such as calcium, that could be used to improve the bioavailability of iron if a significant colonic absorption of iron were to occur. Iron (iron gluconate, 100 microM) absorption by the caecum of the rat was compared with that in proximal sites of the small bowel using the Ussing chamber model; the influence of probiotic bacteria (Propionibacterium freudenreichii) on iron absorption was assessed and compared with that of two of their fermentation products (acetic and propionic acids) using the Ussing chamber and the ligated colon with gamma emitting iron as experimental models. The caecum absorbed less iron than the duodenum, but significantly more than the jejunum and ileum. This occurred mainly through an enhanced mucosal transfer of iron uptake. Propionibacteria enhanced iron absorption from the proximal colon; the same effect was observed in the presence of viable bacteria, or the culture medium free of viable bacteria, or acetate and propionate or propionate alone. The proximal colon could be a significant site available for iron absorption; this absorption can be enhanced by local production of short-chain fatty acids such as propionate.

  7. Effect of applying lactic acid bacteria and propionic acid on fermentation quality and aerobic stability of oats-common vetch mixed silage on the Tibetan plateau.

    PubMed

    Zhang, Jie; Guo, Gang; Chen, Lei; Li, Junfeng; Yuan, Xianjun; Yu, Chengqun; Shimojo, Masataka; Shao, Tao

    2015-06-01

    The objective of this study was to evaluate effects of lactic acid bacteria and propionic acid on the fermentation quality and aerobic stability of oats-common vetch mixed silage by using a small-scale fermentation system on the Tibetan plateau. (i) An inoculant (Lactobacillus plantarum) (L) or (ii) propionic acid (P) or (iii) inoculant + propionic acid (PL) were used as additives. After fermenting for 60 days, silos were opened and the aerobic stability was tested for the following 15 days. The results showed that all silages were well preserved with low pH and NH3 -N, and high lactic acid content and V-scores. L and PL silages showed higher (P < 0.05) lactic acid and crude protein content than the control silage. P silage inhibited lactic acid production. Under aerobic conditions, L silage had similar yeast counts as the control silage (> 10(5) cfu/g fresh matter (FM)); however, it numerically reduced aerobic stability for 6 h. P and PL silages showed fewer yeasts (< 10(5) cfu/g FM) (P < 0.05) and markedly improved the aerobic stability (> 360 h). The result suggested that PL is the best additive as it could not only improved fermentation quality, but also aerobic stability of oats-common vetch mixed silage on the Tibetan plateau. © 2014 Japanese Society of Animal Science.

  8. Characterization of cucumber fermentation spoilage bacteria by enrichment culture and 16S rDNA cloning.

    PubMed

    Breidt, Fred; Medina, Eduardo; Wafa, Doria; Pérez-Díaz, Ilenys; Franco, Wendy; Huang, Hsin-Yu; Johanningsmeier, Suzanne D; Kim, Jae Ho

    2013-03-01

    Commercial cucumber fermentations are typically carried out in 40000 L fermentation tanks. A secondary fermentation can occur after sugars are consumed that results in the formation of acetic, propionic, and butyric acids, concomitantly with the loss of lactic acid and an increase in pH. Spoilage fermentations can result in significant economic loss for industrial producers. The microbiota that result in spoilage remain incompletely defined. Previous studies have implicated yeasts, lactic acid bacteria, enterobacteriaceae, and Clostridia as having a role in spoilage fermentations. We report that Propionibacterium and Pectinatus isolates from cucumber fermentation spoilage converted lactic acid to propionic acid, increasing pH. The analysis of 16S rDNA cloning libraries confirmed and expanded the knowledge gained from previous studies using classical microbiological methods. Our data show that Gram-negative anaerobic bacteria supersede Gram-positive Fermincutes species after the pH rises from around 3.2 to pH 5, and propionic and butyric acids are produced. Characterization of the spoilage microbiota is an important first step in efforts to prevent cucumber fermentation spoilage. An understanding of the microorganisms that cause commercial cucumber fermentation spoilage may aid in developing methods to prevent the spoilage from occurring. © 2013 Institute of Food Technologists®

  9. Characterization of nitrate-reducing and amino acid-using bacteria prominent in nitrotoxin-enriched equine cecal populations

    USDA-ARS?s Scientific Manuscript database

    In the present study, populations of equine cecal microbes enriched for enhanced rates of 3-nitro-1-propionic acid (NPA) or nitrate metabolism were diluted and cultured for NPA-metabolizing bacteria on a basal enrichment medium (BEM) or tryptose soy agar (TSA) medium supplemented with either 5 mM NP...

  10. Feeding of the water extract from Ganoderma lingzhi to rats modulates secondary bile acids, intestinal microflora, mucins, and propionate important to colon cancer.

    PubMed

    Yang, Yongshou; Nirmagustina, Dwi Eva; Kumrungsee, Thanutchaporn; Okazaki, Yukako; Tomotake, Hiroyuki; Kato, Norihisa

    2017-09-01

    Consumption of reishi mushroom has been reported to prevent colon carcinogenesis in rodents, although the underlying mechanisms remain unclear. To investigate this effect, rats were fed a high-fat diet supplemented with 5% water extract from either the reishi mushroom (Ganoderma lingzhi) (WGL) or the auto-digested reishi G. lingzhi (AWGL) for three weeks. Both extracts markedly reduced fecal secondary bile acids, such as lithocholic acid and deoxycholic acid (colon carcinogens). These extracts reduced the numbers of Clostridium coccoides and Clostridium leptum (secondary bile acids-producing bacteria) in a per g of cecal digesta. Fecal mucins and cecal propionate were significantly elevated by both extracts, and fecal IgA was significantly elevated by WGL, but not by AWGL. These results suggest that the reishi extracts have an impact on colon luminal health by modulating secondary bile acids, microflora, mucins, and propionate that related to colon cancer.

  11. Influence of modified atmosphere packaging on the shelf life of prebaked pizza dough with and without preservative added.

    PubMed

    Rodríguez, Valle; Medina, Luis; Jordano, Rafael

    2003-04-01

    The possible effect of different modified atmospheres on the shelf life of prebaked pizza dough, with and without added calcium propionate, was investigated. Three packaging atmospheres were tested: 20% CO2: 80% N2, 50% CO2: 50% N2, 100% CO2, and air (control). Samples were examined daily for visible mold growth and analysed after 2, 8, 17 and 31 days throughout storage (15-20 degrees C and 54-65% relative humidity, RH) for changes in gaseous composition, pH and microbial populations (mesophilic aerobic and anaerobic bacteria, lactic acid bacteria (LAB), and yeasts and molds). Microbiological results showed that molds had a greater sensitivity to CO2 than bacteria and yeasts. Products containing calcium propionate did not show mold growth throughout storage (31 days) when packaged in air or in CO2-enriched atmospheres (20, 50 and 100%). However, in pizza dough without preservative (calcium propionate), mold growth was evident after 7 days, except under 100% CO2 atmosphere (13 days) regardless of the packaging atmosphere. From these results we conclude that the addition of calcium propionate had more and decisive influence on the shelf life extension of prebaked pizza dough.

  12. Studies on potential effects of fumaric acid on rumen microbial fermentation, methane production and microbial community.

    PubMed

    Riede, Susanne; Boguhn, Jeannette; Breves, Gerhard

    2013-01-01

    The greenhouse gas methane (CH4) contributes substantially to global climate change. As a potential approach to decrease ruminal methanogenesis, the effects of different dosages of fumaric acid (FA) on ruminal microbial metabolism and on the microbial community (archaea, bacteria) were studied using a rumen simulation technique (RUSITEC). FA acts as alternative hydrogen acceptor diverting 2H from methanogenesis of archaea towards propionate formation of bacteria. Three identical trials were conducted with 12 fermentation vessels over a period of 14 days. In each trial, four fermentation vessels were assigned to one of the three treatment groups differing in FA dosage: low fumaric acid (LFA), high fumaric acid (HFA) and without FA (control). FA was continuously infused with the buffer. Grass silage and concentrate served as substrate. FA led to decreases in pH and to higher production rates of total short chain fatty acids (SCFA) mediated by increases in propionate for LFA of 1.69 mmol d(-1) and in propionate and acetate production for HFA of 4.49 and 1.10 mmol d(-1), respectively. Concentrations of NH3-N, microbial crude protein synthesis, their efficiency, degradation of crude nutrients and detergent fibre fraction were unchanged. Total gas and CH4 production were not affected by FA. Effects of FA on structure of microbial community by means of single strand conformation polymorphism (SSCP) analyses could not be detected. Given the observed increase in propionate production and the unaffected CH4 production it can be supposed that the availability of reduction equivalents like 2H was not limited by the addition of FA in this study. It has to be concluded from the present study that the application of FA is not an appropriate approach to decrease the ruminal CH4 production.

  13. Digestion of rice straw and oil palm fronds by microflora from rumen and termite bacteria, in vitro.

    PubMed

    Ramin, M; Alimon, A R; Panandam, J M; Sijam, K; Javanmard, A; Abdullah, N

    2008-02-15

    The digestion and Volatile Fatty Acid (VFA) production from rice straw and oil palm fronds by cellulolytic bacteria isolated from the termite Coptotermes curvignathus were investigated. The bacteria were Acinetobacter strain Raminalimon, Enterobacter aerogenes strain Razmin C, Enterobacter cloacae strain Razmin B, Bacillus cereus strain Razmin A and Chryseobacterium kwangyangense strain Cb. Acinetobacter strain Raminalimon is an aerobic bacterium, while the other species are facultative anaerobes. There were significant differences (p<0.05) among the bacteria for Dry Matter (DM) lost and acetic acid production from rice straw and Acinetobacter strain Raminalimon showed the highest activity. The facultative bacteria C. kwangyangense strain Cb (cfu mL(-1) 231 x 10(-6), OD: 0.5), E. cloacae (cfu mL(-1) 68 x 10(-7), OD: 0.5) and E. aerogenes (cfu mL(-1) 33 x 10(-7), OD: 0.5) were used for digestion study with the rumen fluid microflora. The in vitro gas production technique was applied for the comparative study and the parameters measured were pH, gas (volume), dry matter lost, acetic acid, propionic acid and butyric acid concentrations. pH was not significantly (p<0.05) different among the five treatments. The bacterium C. kwangyangense strain Cb showed the highest activity (p<0.05) for DM lost, acetic acid, propionic acid and butyric acid production from rice straw when compared to the other bacterial activities. There was no significance (p<0.05) difference between the three bacteria for the dry matter lost of oil palm fronds but the production of Volatile Fatty Acids (VFA) was significantly (p<0.05) high in the treatment which was inoculated with C. kwangyangense strain Cb. The Gen Bank NCBI/EMBL accession numbers for the bacterial strains are EU332791, EU305608, EU305609, EU294508 and EU169201.

  14. Glycerol Enhances the Antifungal Activity of Dairy Propionibacteria

    PubMed Central

    Lind, Helena; Broberg, Anders; Jacobsson, Karin; Jonsson, Hans; Schnürer, Johan

    2010-01-01

    Dairy propionibacteria are widely used in starter cultures for Swiss type cheese. These bacteria can ferment glucose, lactic acid, and glycerol into propionic acid, acetic acid, and carbon dioxide. This research examined the antifungal effect of dairy propionibacteria when glycerol was used as carbon source for bacterial growth. Five type strains of propionibacteria were tested against the yeast Rhodotorula mucilaginosa and the molds Penicillium commune and Penicillium roqueforti. The conversion of 13C glycerol by Propionibacterium jensenii was followed with nuclear magnetic resonance. In a dual culture assay, the degree of inhibition of the molds was strongly enhanced by an increase in glycerol concentrations, while the yeast was less affected. In broth cultures, decreased pH in glycerol medium was probably responsible for the complete inhibition of the indicator fungi. NMR spectra of the glycerol conversion confirmed that propionic acid was the dominant metabolite. Based on the results obtained, the increased antifungal effect seen by glycerol addition to cultures of propionibacteria is due to the production of propionic acid and pH reduction of the medium. PMID:21331381

  15. Characterization of cucumber fermentation spoilage bacteria by enrichment culture and 16S rDNA cloning

    USDA-ARS?s Scientific Manuscript database

    Commercial cucumber fermentations are typically carried out in 40000 L fermentation tanks. A secondary fermentation can occur after sugars are consumed that results in the formation of acetic, propionic, and butyric acids, concomitantly with the loss of lactic acid and an increase in pH. Spoilage fe...

  16. Use of Acetate, Propionate, and Butyrate for Reduction of Nitrate and Sulfate and Methanogenesis in Microcosms and Bioreactors Simulating an Oil Reservoir

    PubMed Central

    Shen, Yin; An, Dongshan; Voordouw, Gerrit

    2017-01-01

    ABSTRACT Acetate, propionate, and butyrate (volatile fatty acids [VFA]) occur in oil field waters and are frequently used for microbial growth of oil field consortia. We determined the kinetics of use of these VFA components (3 mM each) by an anaerobic oil field consortium in microcosms containing 2 mM sulfate and 0, 4, 6, 8, or 13 mM nitrate. Nitrate was reduced first, with a preference for acetate and propionate. Sulfate reduction then proceeded with propionate (but not butyrate) as the electron donor, whereas the fermentation of butyrate (but not propionate) was associated with methanogenesis. Microbial community analyses indicated that Paracoccus and Thauera (Paracoccus-Thauera), Desulfobulbus, and Syntrophomonas-Methanobacterium were the dominant taxa whose members catalyzed these three processes. Most-probable-number assays showed the presence of up to 107/ml of propionate-oxidizing sulfate-reducing bacteria (SRB) in waters from the Medicine Hat Glauconitic C field. Bioreactors with the same concentrations of sulfate and VFA responded similarly to increasing concentrations of injected nitrate as observed in the microcosms: sulfide formation was prevented by adding approximately 80% of the nitrate dose needed to completely oxidize VFA to CO2 in both. Thus, this work has demonstrated that simple time-dependent observations of the use of acetate, propionate, and butyrate for nitrate reduction, sulfate reduction, and methanogenesis in microcosms are a good proxy for these processes in bioreactors, monitoring of which is more complex. IMPORTANCE Oil field volatile fatty acids acetate, propionate, and butyrate were specifically used for nitrate reduction, sulfate reduction, and methanogenic fermentation. Time-dependent analyses of microcosms served as a good proxy for these processes in a bioreactor, mimicking a sulfide-producing (souring) oil reservoir: 80% of the nitrate dose required to oxidize volatile fatty acids to CO2 was needed to prevent souring in both. Our data also suggest that propionate is a good substrate to enumerate oil field SRB. PMID:28130297

  17. Microbial carbon metabolism associated with electrogenic sulphur oxidation in coastal sediments.

    PubMed

    Vasquez-Cardenas, Diana; van de Vossenberg, Jack; Polerecky, Lubos; Malkin, Sairah Y; Schauer, Regina; Hidalgo-Martinez, Silvia; Confurius, Veronique; Middelburg, Jack J; Meysman, Filip J R; Boschker, Henricus T S

    2015-09-01

    Recently, a novel electrogenic type of sulphur oxidation was documented in marine sediments, whereby filamentous cable bacteria (Desulfobulbaceae) are mediating electron transport over cm-scale distances. These cable bacteria are capable of developing an extensive network within days, implying a highly efficient carbon acquisition strategy. Presently, the carbon metabolism of cable bacteria is unknown, and hence we adopted a multidisciplinary approach to study the carbon substrate utilization of both cable bacteria and associated microbial community in sediment incubations. Fluorescence in situ hybridization showed rapid downward growth of cable bacteria, concomitant with high rates of electrogenic sulphur oxidation, as quantified by microelectrode profiling. We studied heterotrophy and autotrophy by following (13)C-propionate and -bicarbonate incorporation into bacterial fatty acids. This biomarker analysis showed that propionate uptake was limited to fatty acid signatures typical for the genus Desulfobulbus. The nanoscale secondary ion mass spectrometry analysis confirmed heterotrophic rather than autotrophic growth of cable bacteria. Still, high bicarbonate uptake was observed in concert with the development of cable bacteria. Clone libraries of 16S complementary DNA showed numerous sequences associated to chemoautotrophic sulphur-oxidizing Epsilon- and Gammaproteobacteria, whereas (13)C-bicarbonate biomarker labelling suggested that these sulphur-oxidizing bacteria were active far below the oxygen penetration. A targeted manipulation experiment demonstrated that chemoautotrophic carbon fixation was tightly linked to the heterotrophic activity of the cable bacteria down to cm depth. Overall, the results suggest that electrogenic sulphur oxidation is performed by a microbial consortium, consisting of chemoorganotrophic cable bacteria and chemolithoautotrophic Epsilon- and Gammaproteobacteria. The metabolic linkage between these two groups is presently unknown and needs further study.

  18. 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.

  19. Use of an acidophilic yeast strain to enable the growth of leaching bacteria on solid media.

    PubMed

    Ngom, Baba; Liang, Yili; Liu, Yi; Yin, Huaqun; Liu, Xueduan

    2015-03-01

    In this study, a Candida digboiensis strain was isolated from a heap leaching plant in Zambia and used in double-layer agar plate to efficiently isolate and purify leaching bacteria. Unlike Acidiphilium sp., the yeast strain was tetrathionate tolerant and could metabolize a great range of organic compounds including organic acids. These properties allowed the yeast strain to enable and fasten the growth of iron and sulfur oxidizers on double-layer agar plate. The isolates were identified as Acidithiobacillus ferrooxidans FOX1, Leptospirillun ferriphilum BN, and Acidithiobacillus thiooxidans ZMB. These three leaching bacteria were inhibited by organic acids such as acetic and propionic acids; however, their activities were enhanced by Candida digboiensis NB under dissolved organic matter stress.

  20. Chemical composition, silage fermentation characteristics, and in vitro ruminal fermentation parameters of potato-wheat straw silage treated with molasses and lactic acid bacteria and corn silage.

    PubMed

    Babaeinasab, Y; Rouzbehan, Y; Fazaeli, H; Rezaei, J

    2015-09-01

    The aim of this study was to determine the effect of molasses and lactic acid bacteria (LAB) on the chemical composition, silage fermentation characteristics, and in vitro ruminal fermentation parameters of an ensiled potato-wheat straw mixture in a completely randomized design with 4 replicates. Wheat straw was harvested at full maturity and potato tuber when the leaves turned yellowish. The potato-wheat straw (57:43 ratio, DM basis) mixture was treated with molasses, LAB, or a combination. Lalsil Fresh LB (Lallemand, France; containing NCIMB 40788) or Lalsil MS01 (Lallemand, France; containing MA18/5U and MA126/4U) were each applied at a rate of 3 × 10 cfu/g of fresh material. Treatments were mixed potato-wheat straw silage (PWSS) without additive, PWSS inoculated with Lalsil Fresh LB, PWSS inoculated with Lalsil MS01, PWSS + 5% molasses, PWSS inoculated with Lalsil Fresh LB + 5% molasses, PWSS inoculated with Lalsil MS01 + 5% molasses, and corn silage (CS). The compaction densities of PWSS treatments and CS were approximately 850 and 980 kg wet matter/m, respectively. After anaerobic storage for 90 d, chemical composition, silage fermentation characteristics, in vitro gas production (GP), estimated OM disappearance (OMD), ammonia-N, VFA, microbial CP (MCP) production, and cellulolytic bacteria count were determined. Compared to CS, PWSS had greater ( < 0.001) values of DM, ADL, water-soluble carbohydrates, pH, and ammonia-N but lower ( < 0.05) values of CP, ash free-NDF (NDFom), ash, nitrate, and lactic, acetic, propionic, and butyric acids concentrations. When PWSS was treated with molasses, LAB, or both, the contents of CP and lactic and acetic acids increased, whereas NDFom, ammonia-N, and butyric acid decreased ( < 0.05). Based on in vitro ruminal experiments, PWSS had greater ( < 0.05) values of GP, OMD, and MCP but lower ( < 0.05) VFA and acetic acid compared to CS. With adding molasses alone or in combination with LAB inoculants to PWSS, the values of GP, OMD, MCP, cellulolytic bacteria population, VFA, and propionic acid increased ( < 0.05), whereas the acetic acid to propionic acid ratio decreased ( < 0.05). Overall, ensiling potato with wheat straw at a 57:43 ratio DM basis was possible; nevertheless, the fermentation quality of PWSS was lesser than that of CS. However, addition of molasses and molasses + LAB improved fermentation quality of PWSS.

  1. Evidence and Role for Bacterial Mucin Degradation in Cystic Fibrosis Airway Disease

    PubMed Central

    Flynn, Jeffrey M.; Niccum, David; Dunitz, Jordan M.

    2016-01-01

    Chronic lung infections in cystic fibrosis (CF) patients are composed of complex microbial communities that incite persistent inflammation and airway damage. Despite the high density of bacteria that colonize the lower airways, nutrient sources that sustain bacterial growth in vivo, and how those nutrients are derived, are not well characterized. In this study, we examined the possibility that mucins serve as an important carbon reservoir for the CF lung microbiota. While Pseudomonas aeruginosa was unable to efficiently utilize mucins in isolation, we found that anaerobic, mucin-fermenting bacteria could stimulate the robust growth of CF pathogens when provided intact mucins as a sole carbon source. 16S rRNA sequencing and enrichment culturing of sputum also identified that mucin-degrading anaerobes are ubiquitous in the airways of CF patients. The collective fermentative metabolism of these mucin-degrading communities in vitro generated amino acids and short chain fatty acids (propionate and acetate) during growth on mucin, and the same metabolites were also found in abundance within expectorated sputum. The significance of these findings was supported by in vivo P. aeruginosa gene expression, which revealed a heightened expression of genes required for the catabolism of propionate. Given that propionate is exclusively derived from bacterial fermentation, these data provide evidence for an important role of mucin fermenting bacteria in the carbon flux of the lower airways. More specifically, microorganisms typically defined as commensals may contribute to airway disease by degrading mucins, in turn providing nutrients for pathogens otherwise unable to efficiently obtain carbon in the lung. PMID:27548479

  2. Use of Acetate, Propionate, and Butyrate for Reduction of Nitrate and Sulfate and Methanogenesis in Microcosms and Bioreactors Simulating an Oil Reservoir.

    PubMed

    Chen, Chuan; Shen, Yin; An, Dongshan; Voordouw, Gerrit

    2017-04-01

    Acetate, propionate, and butyrate (volatile fatty acids [VFA]) occur in oil field waters and are frequently used for microbial growth of oil field consortia. We determined the kinetics of use of these VFA components (3 mM each) by an anaerobic oil field consortium in microcosms containing 2 mM sulfate and 0, 4, 6, 8, or 13 mM nitrate. Nitrate was reduced first, with a preference for acetate and propionate. Sulfate reduction then proceeded with propionate (but not butyrate) as the electron donor, whereas the fermentation of butyrate (but not propionate) was associated with methanogenesis. Microbial community analyses indicated that Paracoccus and Thauera ( Paracoccus - Thauera ), Desulfobulbus , and Syntrophomonas - Methanobacterium were the dominant taxa whose members catalyzed these three processes. Most-probable-number assays showed the presence of up to 10 7 /ml of propionate-oxidizing sulfate-reducing bacteria (SRB) in waters from the Medicine Hat Glauconitic C field. Bioreactors with the same concentrations of sulfate and VFA responded similarly to increasing concentrations of injected nitrate as observed in the microcosms: sulfide formation was prevented by adding approximately 80% of the nitrate dose needed to completely oxidize VFA to CO 2 in both. Thus, this work has demonstrated that simple time-dependent observations of the use of acetate, propionate, and butyrate for nitrate reduction, sulfate reduction, and methanogenesis in microcosms are a good proxy for these processes in bioreactors, monitoring of which is more complex. IMPORTANCE Oil field volatile fatty acids acetate, propionate, and butyrate were specifically used for nitrate reduction, sulfate reduction, and methanogenic fermentation. Time-dependent analyses of microcosms served as a good proxy for these processes in a bioreactor, mimicking a sulfide-producing (souring) oil reservoir: 80% of the nitrate dose required to oxidize volatile fatty acids to CO 2 was needed to prevent souring in both. Our data also suggest that propionate is a good substrate to enumerate oil field SRB. Copyright © 2017 American Society for Microbiology.

  3. Humic Acid Reduction by Propionibacterium freudenreichii and Other Fermenting Bacteria

    PubMed Central

    Benz, Marcus; Schink, Bernhard; Brune, Andreas

    1998-01-01

    Iron-reducing bacteria have been reported to reduce humic acids and low-molecular-weight quinones with electrons from acetate or hydrogen oxidation. Due to the rapid chemical reaction of amorphous ferric iron with the reduced reaction products, humic acids and low-molecular-weight redox mediators may play an important role in biological iron reduction. Since many anaerobic bacteria that are not able to reduce amorphous ferric iron directly are known to transfer electrons to other external acceptors, such as ferricyanide, 2,6-anthraquinone disulfonate (AQDS), or molecular oxygen, we tested several physiologically different species of fermenting bacteria to determine their abilities to reduce humic acids. Propionibacterium freudenreichii, Lactococcus lactis, and Enterococcus cecorum all shifted their fermentation patterns towards more oxidized products when humic acids were present; P. freudenreichii even oxidized propionate to acetate under these conditions. When amorphous ferric iron was added to reoxidize the electron acceptor, humic acids were found to be equally effective when they were added in substoichiometric amounts. These findings indicate that in addition to iron-reducing bacteria, fermenting bacteria are also capable of channeling electrons from anaerobic oxidations via humic acids towards iron reduction. This information needs to be considered in future studies of electron flow in soils and sediments. PMID:9797315

  4. Quantification of Propionic Acid in the Bovine Spinal Disk After Infection of the Tissue With Propionibacteria acnes Bacteria.

    PubMed

    Magnitsky, Sergey; Dudli, Stefan; Tang, Xinyan; Kaur, Jaskanwaljeet; Diaz, Joycelyn; Miller, Steve; Lotz, Jeffrey C

    2018-06-01

    Research. The goal of this study was to investigate whether Propionibacteria acnes infection of the intervertebral disc can be detected noninvasively by nuclear magnetic resonance (NMR) spectroscopy. Microbiological studies of surgical samples suggest that a significant subpopulation of back pain patients may have occult disc infection with P. acnes bacteria. This hypothesis is further supported by a double-blind clinical trial showing that back pain patients with Modic type 1 changes may respond to antibiotic treatment. Because significant side effects are associated with antibiotic treatment, there is a need for a noninvasive method to detect whether specific discs in back pain patients are infected with P acnes bacteria. P. acnes bacteria were obtained from human patients. NMR detection of a propionic acid (PA) in the bacteria extracts was conducted on 500 MHz high-resolution spectrometer, whereas in vivo NMR spectroscopy of an isolated bovine disk tissue infected with P. acnes was conducted on 7 T magnetic resonance imaging scanner. NMR spectra of P. acnes metabolites revealed a distinct NMR signal with identical chemical shits (1.05 and 2.18 ppm) as PA (a primary P. acne metabolite). The 1.05 ppm signal does not overlap with other bacteria metabolites, and its intensity increases linearly with P. acnes concentration. Bovine disks injected with P. acnes bacteria revealed a very distinct NMR signal at 1.05 ppm, which linearly increased with P. acnes concentration. The 1.05 ppm NMR signal from PA can be used as a marker of P. acnes infection of discs. This signal does not overlap with other disc metabolites and linearly depends on P. acnes concentration. Consequently, NMR spectroscopy may provide a noninvasive method to detect disc infection in the clinical setting. N/A.

  5. A novel extractive fermentation process for propionic acid production from whey lactose

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

    Lewis, V.P.; Yang, Shangtian

    An extractive fermentation process was developed to produce propionate from lactose. The bacterium Propionibacterium acidipropionici was immobilized in a spiral wound, fibrous matrix packed in the reactor. Propionic acid is the major product from lactose fermentation, with acetic acid and carbon dioxide as byproducts. Propionic acid is a strong inhibitor to this fermentation. A tertiary amine was used to selectively extract propionic acid from the bioreactor, hence enhancing reactor productivity by over 100%. The authors also speculate that by selectively extracting propionic acid, lactose metabolism can be directed to yield more propionate and less byproducts. Other advantages of extractive fermentationmore » include better pH control and a purer product. The propionic acid present in the extractant can be easily stripped with small amounts of an alkaline solution, resulting in a concentrated propionate salt. The extractant was also regenerated in this stripping step. Thus, the process is energy-efficient and economically attractive.« less

  6. Small (13)C/(12)C fractionation contrasts with large enantiomer fractionation in aerobic biodegradation of phenoxy acids.

    PubMed

    Qiu, Shiran; Gözdereliler, Erkin; Weyrauch, Philip; Lopez, Eva C Magana; Kohler, Hans-Peter E; Sørensen, Sebastian R; Meckenstock, Rainer U; Elsner, Martin

    2014-05-20

    Phenoxy acid herbicides are important groundwater contaminants. Stable isotope analysis and enantiomer analysis are well-recognized approaches for assessing in situ biodegradation in the field. In an aerobic degradation survey with six phenoxyacetic acid and three phenoxypropionic acid-degrading bacteria we measured (a) enantiomer-specific carbon isotope fractionation of MCPP ((R,S)-2-(4-chloro-2-methylphenoxy)-propionic acid), DCPP ((R,S)-2-(2,4-dichlorophenoxy)-propionic acid), and 4-CPP ((R,S)-2-(4-chlorophenoxy)-propionic acid); (b) compound-specific isotope fractionation of MCPA (4-chloro-2-methylphenoxyacetic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid); and (c) enantiomer fractionation of MCPP, DCPP, and 4-CPP. Insignificant or very slight (ε = -1.3‰ to -2.0‰) carbon isotope fractionation was observed. Equally small values in an RdpA enzyme assay (εea = -1.0 ± 0.1‰) and even smaller fractionation in whole cell experiments of the host organism Sphingobium herbicidovorans MH (εwc = -0.3 ± 0.1‰) suggest that (i) enzyme-associated isotope effects were already small, yet (ii) further masked by active transport through the cell membrane. In contrast, enantiomer fractionation in MCPP, DCPP, and 4-CPP was pronounced, with enantioselectivities (ES) of -0.65 to -0.98 with Sphingomonas sp. PM2, -0.63 to -0.89 with Sphingobium herbicidovorans MH, and 0.74 to 0.97 with Delftia acidovorans MC1. To detect aerobic biodegradation of phenoxypropionic acids in the field, enantiomer fractionation seems, therefore, a stronger indicator than carbon isotope fractionation.

  7. Candidatus "Anammoxoglobus propionicus" a new propionate oxidizing species of anaerobic ammonium oxidizing bacteria.

    PubMed

    Kartal, Boran; Rattray, Jayne; van Niftrik, Laura A; van de Vossenberg, Jack; Schmid, Markus C; Webb, Richard I; Schouten, Stefan; Fuerst, John A; Damsté, Jaap Sinninghe; Jetten, Mike S M; Strous, Marc

    2007-01-01

    The bacteria that mediate the anaerobic oxidation of ammonium (anammox) are detected worldwide in natural and man-made ecosystems, and contribute up to 50% to the loss of inorganic nitrogen in the oceans. Two different anammox species rarely live in a single habitat, suggesting that each species has a defined but yet unknown niche. Here we describe a new anaerobic ammonium oxidizing bacterium with a defined niche: the co-oxidation of propionate and ammonium. The new anammox species was enriched in a laboratory scale bioreactor in the presence of ammonium and propionate. Interestingly, this particular anammox species could out-compete other anammox bacteria and heterotrophic denitrifiers for the oxidation of propionate in the presence of ammonium, nitrite and nitrate. We provisionally named the new species Candidatus "Anammoxoglobus propionicus".

  8. Antifungal activity of Leuconostoc citreum and Weissella confusa in rice cakes.

    PubMed

    Baek, Eunjong; Kim, Hyojin; Choi, Hyejung; Yoon, Sun; Kim, Jeongho

    2012-10-01

    The antifungal activity of organic acids greatly improves the shelf life of bread and bakery products. However, little is known about the effect of lactic acid fermentation on fungal contamination in rice cakes. Here, we show that lactic acid fermentation in rice dough can greatly retard the growth of three fungal species when present in rice cakes, namely Cladosporium sp. YS1, Neurospora sp. YS3, and Penicillium crustosum YS2. The antifungal activity of the lactic acid bacteria against these fungi was much better than that of 0.3% calcium propionate. We found that organic acids including lactic and acetic acid, which are byproducts of lactic fermentation or can be artificially added, were the main antifungal substances. We also found that some Leuconostoc citreum and Weissella confusa strains could be good starter species for rice dough fermentation. These results imply that these lactic acid bacteria can be applicable to improve the preservation of rice cakes.

  9. Effects of four short-chain fatty acids or salts on fermentation characteristics and aerobic stability of alfalfa (Medicago sativa L.) silage.

    PubMed

    Yuan, Xian J; Wen, Ai Y; Wang, Jian; Desta, Seare T; Dong, Zhi H; Shao, Tao

    2018-01-01

    The objective of the present study was to evaluate the effects of four chemicals on the fermentation quality and aerobic stability of alfalfa (Medicago sativa L.) silage. Wilted alfalfa was ensiled without additive (control), or with formic acid (FA), potassium diformate (KDF), sodium diacetate (SDA) or calcium propionate (CAP). After 60 days of ensiling, the pH values in FA, KDF and SDA silages were lower (P < 0.05) compared to that of control and CAP silages, and chemicals (P < 0.05) decreased butyric acid and ammonia N concentrations and populations of aerobic bacteria and yeasts compared to the control. The SDA and CAP silages had a higher (P < 0.05) lactic acid bacteria content compared to the FA and KDF silages. The SDA and CAP silages had higher (P < 0.05) acetic and propionic acid contents compared to the other silages, respectively. The ammonia N concentrations in the FA and KDF silages were lower compared to the other silages during the first 5 days of aerobic exposure, and then increased sharply to 105 and 100 g kg -1 total N, respectively, which was higher (P < 0.05) than that of the SDA and CAP silages on day 9 of aerobic exposure. Yeasts and aerobic bacteria counts in SDA silage slowly increased and remained at lower levels compared to the other silages after 7 days of aerobic exposure. Additives prolonged the aerobic stability duration compared to the control, and the SDA and CAP silages remained stable for more than 216 h, followed by the KDF and FA silages (202 and 196 h, respectively). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. 21 CFR 582.3081 - Propionic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propionic acid. 582.3081 Section 582.3081 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Propionic acid. (a) Product. Propionic acid. (b) Conditions of use. This substance is generally recognized...

  11. Effect of propionic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    PubMed

    Xu, Jian; Bao, Jia-Wei; Su, Xian-Feng; Zhang, Hong-Jian; Zeng, Xin; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2016-03-01

    In this study, an integrated citric acid-methane fermentation process was established to solve the problem of wastewater treatment in citric acid production. Citric acid wastewater was treated through anaerobic digestion and then the anaerobic digestion effluent (ADE) was further treated and recycled for the next batch citric acid fermentation. This process could eliminate wastewater discharge and reduce water resource consumption. Propionic acid was found in the ADE and its concentration continually increased in recycling. Effect of propionic acid on citric acid fermentation was investigated, and results indicated that influence of propionic acid on citric acid fermentation was contributed to the undissociated form. Citric acid fermentation was inhibited when the concentration of propionic acid was above 2, 4, and 6 mM in initial pH 4.0, 4.5 and, 5.0, respectively. However, low concentration of propionic acid could promote isomaltase activity which converted more isomaltose to available sugar, thereby increasing citric acid production. High concentration of propionic acid could influence the vitality of cell and prolong the lag phase, causing large amount of glucose still remaining in medium at the end of fermentation and decreasing citric acid production.

  12. In vitro metabolism of radiolabeled carbohydrates by protective cecal anaerobic bacteria.

    PubMed

    Hume, M E; Beier, R C; Hinton, A; Scanlan, C M; Corrier, D E; Peterson, D V; DeLoach, J R

    1993-12-01

    Cecal anaerobic bacteria from adult broilers were cultured in media containing .25% glucose or .25% lactose. Media also contained either [14C]-labeled lactose, glucose, galactose, or lactic acid as metabolic tracers. Cultures were analyzed at 4, 8, and 12 h for pH, radiolabeled and unlabeled volatile fatty acids, and lactic acid. The pH values of cultures containing .25% lactose were significantly (P < .05) higher than the pH values of cultures containing .25% glucose. Lactose cultures reached their lowest pH more slowly than glucose cultures. Concentrations of unlabeled volatile fatty acids increased and lactic acid decreased during incubation of the cultures. Radiolabeled sugars and lactic acid were more readily metabolized to volatile fatty acids in media containing lactose than in media containing glucose. The preferred metabolism of [14C]substrates, independent of media carbohydrate, was in the following order: lactic acid > galactose, lactose > glucose. The volatile fatty acids in which radiolabel was most concentrated were acetic acid, propionic acid, or butyric acid.

  13. 40 CFR 180.325 - 2-(m-Chlorophenoxy) propionic acid; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false 2-(m-Chlorophenoxy) propionic acid... Tolerances § 180.325 2-(m-Chlorophenoxy) propionic acid; tolerances for residues. (a) General. A tolerance is established for negligible residues of the plant regulator 2-(m-chlorophenoxy) propionic acid from application...

  14. Microbiological and chemical characteristics of Brazilian kefir during fermentation and storage processes.

    PubMed

    Leite, A M O; Leite, D C A; Del Aguila, E M; Alvares, T S; Peixoto, R S; Miguel, M A L; Silva, J T; Paschoalin, V M F

    2013-07-01

    The microbial community composition and chemical characteristics of a Brazilian milk kefir sample produced during its manufacturing and refrigerated storage were investigated by culture-dependent and -independent methods and HPLC. Lactococcus lactis ssp. cremoris and ssp. lactis, Leuconostoc mesenteroides, Acetobacter lovaniensis, and Saccharomyces cerevisiae were isolated, whereas the detected bands on denaturing gel gradient electrophoresis corresponded to Lactobacillus kefiranofaciens, Lactobacillus kefiri, Lactobacillus parakefiri, and S. cerevisiae. After fermentation, lactic acid bacteria were present at levels of 10 log units, whereas acetic acid bacteria and yeast were present at levels of 7.8 and 6 log units, respectively. The lactic acid bacteria and yeast counts remained constant, whereas acetic acid bacteria counts decreased to 7.2 log units during storage. From fermentation to final storage, the pH, lactose content and citric acid of the kefir beverage decreased, followed by an increase in the concentrations of glucose, galactose, ethanol, and lactic, acetic, butyric, and propionic acids. These microbiological and chemical characteristics contribute to the unique taste and aroma of kefir. This research may serve as a basis for the future industrial production of this beverage in Brazil. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Defined bacterial populations in the rumens of gnotobiotic lambs.

    PubMed

    Lysons, R J; Alexander, T J; Wellstead, P D; Hobson, P N; Mann, S O; Stewart, C S

    1976-06-01

    Five gnotobiotic lambs were fed on sterile diets until they were killed at 13 to 21 weeks of age. They were dosed orally with different combinations of 11 species of rumen bacteria. The biochemical reactions of each of the bacteria inoculated had been determined in pure culture in vitro, and they were chosen to perform the main reactions known to be associated with digestion in the normal mature rumen. Two of the bacteria could not be reisolated, but the remainder had established readily in the rumen, forming stable, mixed, defined populations. The total numbers of bacteria in the rumen, and the viable counts of most of the individual species were comparable to those of normal sheep. The concentration of volatile fatty acids was lower, however, and in four of the lambs there was a higher proportion of butyric acid and a lower proportion of propionic acid than in normal sheep. Cellulolytic, ureolytic, and methanogenic activities appeared to be taking place and lactate-utilizing bacteria appeared to reverse the accumulation of lactate which resulted from the activity of lactate-producing bacteria. Some of the bacteria also established at high levels in the caecum.

  16. Relations between transit time, fermentation products, and hydrogen consuming flora in healthy humans.

    PubMed

    El Oufir, L; Flourié, B; Bruley des Varannes, S; Barry, J L; Cloarec, D; Bornet, F; Galmiche, J P

    1996-06-01

    To investigate whether transit time could influence H2 consuming flora and certain indices of colonic bacterial fermentation. Eight healthy volunteers (four methane excretors and four non-methane excretors) were studied for three, three week periods during which they received a controlled diet alone (control period), and then the same diet with cisapride or loperamide. At the end of each period, mean transit time (MTT) was estimated, an H2 lactulose breath test was performed, and stools were analysed. In the control period, transit time was inversely related to faecal weight, sulphate reducing bacteria counts, concentrations of total short chain fatty acids (SCFAs), propionic and butyric acids, and H2 excreted in breath after lactulose ingestion. Conversely, transit time was positively related to faecal pH and tended to be related to methanogen counts. Methanogenic bacteria counts were inversely related to those of sulphate reducing bacteria and methane excretors had slower MTT and lower sulphate reducing bacteria counts than non-methane excretors. Compared with the control period, MTT was significantly shortened (p < 0.05) by cisapride and prolonged (p < 0.05) by loperamide (73 (11) hours, 47 (5) hours and 147 (12) hours for control, cisapride, and loperamide, respectively, mean (SD)). Cisapride reduced transit time was associated with (a) a significant rise in faecal weight, sulphate reducing bacteria, concentrations of total SCFAs, and propionic and butyric acids and breath H2 as well as (b) a significant fall in faecal pH and breath CH4 excretion, and (c) a non-significant decrease in the counts of methanogenic bacteria. Reverse relations were roughly the same during the loperamide period including a significant rise in the counts of methanogenic bacteria and a significant fall in those of sulphate reducing bacteria. Transit time differences between healthy volunteers are associated with differences in H2 consuming flora and certain indices of colonic fermentation. Considering the effects of some fermentation products on intestinal morphology and function, these variations may be relevant to the pathogenesis of colorectal diseases.

  17. Relations between transit time, fermentation products, and hydrogen consuming flora in healthy humans.

    PubMed Central

    El Oufir, L; Flourié, B; Bruley des Varannes, S; Barry, J L; Cloarec, D; Bornet, F; Galmiche, J P

    1996-01-01

    BACKGROUND/AIMS: To investigate whether transit time could influence H2 consuming flora and certain indices of colonic bacterial fermentation. METHODS: Eight healthy volunteers (four methane excretors and four non-methane excretors) were studied for three, three week periods during which they received a controlled diet alone (control period), and then the same diet with cisapride or loperamide. At the end of each period, mean transit time (MTT) was estimated, an H2 lactulose breath test was performed, and stools were analysed. RESULTS: In the control period, transit time was inversely related to faecal weight, sulphate reducing bacteria counts, concentrations of total short chain fatty acids (SCFAs), propionic and butyric acids, and H2 excreted in breath after lactulose ingestion. Conversely, transit time was positively related to faecal pH and tended to be related to methanogen counts. Methanogenic bacteria counts were inversely related to those of sulphate reducing bacteria and methane excretors had slower MTT and lower sulphate reducing bacteria counts than non-methane excretors. Compared with the control period, MTT was significantly shortened (p < 0.05) by cisapride and prolonged (p < 0.05) by loperamide (73 (11) hours, 47 (5) hours and 147 (12) hours for control, cisapride, and loperamide, respectively, mean (SD)). Cisapride reduced transit time was associated with (a) a significant rise in faecal weight, sulphate reducing bacteria, concentrations of total SCFAs, and propionic and butyric acids and breath H2 as well as (b) a significant fall in faecal pH and breath CH4 excretion, and (c) a non-significant decrease in the counts of methanogenic bacteria. Reverse relations were roughly the same during the loperamide period including a significant rise in the counts of methanogenic bacteria and a significant fall in those of sulphate reducing bacteria. CONCLUSIONS: Transit time differences between healthy volunteers are associated with differences in H2 consuming flora and certain indices of colonic fermentation. Considering the effects of some fermentation products on intestinal morphology and function, these variations may be relevant to the pathogenesis of colorectal diseases. PMID:8984026

  18. Response of Syntrophic Propionate Degradation to pH Decrease and Microbial Community Shifts in an UASB Reactor.

    PubMed

    Zhang, Liguo; Ban, Qiaoying; Li, Jianzheng; Jha, Ajay Kumar

    2016-08-28

    The effect of pH on propionate degradation in an upflow anaerobic sludge blanket (UASB) reactor containing propionate as a sole carbon source was studied. Under influent propionate of 2,000 mg/l and 35ºC, propionate removal at pH 7.5-6.8 was above 93.6%. Propionate conversion was significantly inhibited with stepwise pH decrease from pH 6.8 to 6.5, 6.0, 5.5, 5.0, 4.5, and then to 4.0. After long-term operation, the propionate removal at pH 6.5-4.5 maintained an efficiency of 88.5%-70.1%, whereas propionate was hardly decomposed at pH 4.0. Microbial composition analysis showed that propionate-oxidizing bacteria from the genera Pelotomaculum and Smithella likely existed in this system. They were significantly reduced at pH ≤5.5. The methanogens in this UASB reactor belonged to four genera: Methanobacterium, Methanospirillum, Methanofollis, and Methanosaeta. Most detectable hydrogenotrophic methanogens were able to grow at low pH conditions (pH 6.0-4.0), but the acetotrophic methanogens were reduced as pH decreased. These results indicated that propionate-oxidizing bacteria and acetotrophic methanogens were more sensitive to low pH (5.5-4.0) than hydrogenotrophic methanogens.

  19. Addition of granular activated carbon and trace elements to favor volatile fatty acid consumption during anaerobic digestion of food waste.

    PubMed

    Capson-Tojo, Gabriel; Moscoviz, Roman; Ruiz, Diane; Santa-Catalina, Gaëlle; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

    2018-07-01

    The effect of supplementing granular activated carbon and trace elements on the anaerobic digestion performance of consecutive batch reactors treating food waste was investigated. The results from the first batch suggest that addition of activated carbon favored biomass acclimation, improving acetic acid consumption and enhancing methane production. Adding trace elements allowed a faster consumption of propionic acid. A second batch proved that a synergy existed when activated carbon and trace elements were supplemented simultaneously. The degradation kinetics of propionate oxidation were particularly improved, reducing significantly the batch duration and improving the average methane productivities. Addition of activated carbon favored the growth of archaea and syntrophic bacteria, suggesting that interactions between these microorganisms were enhanced. Interestingly, microbial analyses showed that hydrogenotrophic methanogens were predominant. This study shows for the first time that addition of granular activated carbon and trace elements may be a feasible solution to stabilize food waste anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Comprehensive evaluation of SCFA production in the intestinal bacteria regulated by berberine using gas-chromatography combined with polymerase chain reaction.

    PubMed

    Wang, Lu-Lu; Guo, Hui-Hui; Huang, Shuai; Feng, Chen-Lin; Han, Yan-Xing; Jiang, Jian-Dong

    2017-07-01

    Short-chain fatty acids (SCFAs) of intestine microbial have caught accumulating attention for their beneficial effects on human health. Botanic compounds with low bioavailability such as berberine (BBR) and resveratrol might interact with intestinal microbial ecosystem and promote gut bacteria to produce SCFA, which contribute to their biological effects. In the present study, a comprehensive assay system was built to detect SCFAs production in intestinal bacteria, in which stringent anaerobic culture was applied for in vitro bacterial fermentation, followed by direct-injection GC detection (chemical detection) in combination with real time polymerase chain reaction (RT-PCR, biological detection). BBR was used as positive reference. The direct injection GC method was calibrated and successfully applied to analyze the concentration of SCFAs in gut microbiota and BBR was proved to be effective in the dose- and time-dependent up-regulation of SCFAs production. As compared to the saline group, the concentration of acetic acid, propionate acid and butyric acid (the main SCFAs in gut microbiota) were increased by 17.7%, 11.1% and 30.5%, respectively, after incubating intestinal bacteria with 20μg/mL BBR for 24h. The increase reached to 34.9%, 22.4% and 51.6%, respectively when the BBR was 50μg/mL. Additionally, consensus-degenerate hybrid oligonucleotide primers (CODEHOPs) were designed for the detection of acetate kinase (ACK), Methylmalonyl-CoA decarboxylase (MMD) and butyryl-CoA: acetate-CoA transferase (BUT), as they are the key enzymes in the synthetic pathway for acetic acid, propionate acid and butyric acid, respectively. After 24hr's incubation, BBR was shown to promote the gene expression of ACK, MMD and BUT significantly (86.5%, 27.2% and 60.4%, respectively, with 20μg/mL BBR; 130.2%, 84.2% and 98.4%, respectively, with 50μg/mL BBR), showing a solid biological support for the chemical detection. This comprehensive assay system might be useful in identifying SCFAs promoting agents with information on their mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Organic acid production from potato starch waste fermentation by rumen microbial communities from Dutch and Thai dairy cows.

    PubMed

    Palakawong Na Ayudthaya, Susakul; van de Weijer, Antonius H P; van Gelder, Antonie H; Stams, Alfons J M; de Vos, Willem M; Plugge, Caroline M

    2018-01-01

    Exploring different microbial sources for biotechnological production of organic acids is important. Dutch and Thai cow rumen samples were used as inocula to produce organic acid from starch waste in anaerobic reactors. Organic acid production profiles were determined and microbial communities were compared using 16S ribosomal ribonucleic acid gene amplicon pyrosequencing. In both reactors, lactate was the main initial product and was associated with growth of Streptococcus spp. (86% average relative abundance). Subsequently, lactate served as a substrate for secondary fermentations. In the reactor inoculated with rumen fluid from the Dutch cow, the relative abundance of Bacillus and Streptococcus increased from the start, and lactate, acetate, formate and ethanol were produced. From day 1.33 to 2, lactate and acetate were degraded, resulting in butyrate production. Butyrate production coincided with a decrease in relative abundance of Streptococcus spp. and increased relative abundances of bacteria of other groups, including Parabacteroides , Sporanaerobacter , Helicobacteraceae, Peptostreptococcaceae and Porphyromonadaceae. In the reactor with the Thai cow inoculum, Streptococcus spp. also increased from the start. When lactate was consumed, acetate, propionate and butyrate were produced (day 3-4). After day 3, bacteria belonging to five dominant groups, Bacteroides, Pseudoramibacter _ Eubacterium , Dysgonomonas , Enterobacteriaceae and Porphyromonadaceae, were detected and these showed significant positive correlations with acetate, propionate and butyrate levels. The complexity of rumen microorganisms with high adaptation capacity makes rumen fluid a suitable source to convert organic waste into valuable products without the addition of hydrolytic enzymes. Starch waste is a source for organic acid production, especially lactate.

  2. Ginkgo fruit extract as an additive to modify rumen microbiota and fermentation and to mitigate methane production.

    PubMed

    Oh, S; Shintani, R; Koike, S; Kobayashi, Y

    2017-03-01

    Ginkgo fruit, an unused byproduct of the ginkgo nut industry, contains antimicrobial compounds known as anacardic acids. Two major cultivars of ginkgo, Kyuju (K) and Tokuro (T), were evaluated for their potential as a feed additive for ruminants. In batch culture, we incubated a mixture of hay and concentrate in diluted rumen fluid with or without 1.6% (fruit equivalent) ginkgo fruit extract. We conducted another series of batch culture studies to determine the dose response of fermentation. We also conducted continuous culture using the rumen simulation technique (RUSITEC) with cultivar K and carried out a pure culture study to monitor the sensitivity of 17 representative rumen bacterial species to ginkgo extract and component phenolics. Although both K and T extracts led to decreased methane and increased propionate production, changes were more apparent with K extract, and were dose-dependent. Total gas production was depressed at doses ≥3.2%, suggesting that 1.6% was the optimal supplementation level. In RUSITEC fermentation supplemented with 1.6% ginkgo K, methane decreased by 53% without affecting total gas or total VFA production, but with decreased acetate and increased propionate. Disappearance of dry matter, neutral detergent fiber, and acid detergent fiber were not affected by ginkgo, but ammonia levels were decreased. Quantitative PCR indicated that the abundance of protozoa, fungi, methanogens, and bacteria related to hydrogen and formate production decreased, but the abundance of bacteria related to propionate production increased. MiSeq analysis (Illumina Inc., San Diego, CA) confirmed these bacterial changes and identified archaeal community changes, including a decrease in Methanobrevibacter and Methanomassiliicoccaceae and an increase in Methanoplanus. Pure culture study results supported the findings for the above bacterial community changes. These results demonstrate that ginkgo fruit can modulate rumen fermentation toward methane mitigation and propionate enhancement via microbial selection. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Effects of volatile fatty acids on propionate metabolism and gluconeogenesis in caprine hepatocytes

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

    Aiello, R.J.; Armentano, L.E.

    1987-12-01

    Isolated caprine hepatocytes were incubated with fatty acids of various chain lengths. Short-chain fatty acids effects on rates of gluconeogenesis and oxidation from (2-/sup 14/C) propionate were determined. Additions of glucose (2.5 mM) had no effect on hepatic (2-/sup 14/C)-propionate metabolism in the presence and absence of amino acids. A complete mixture of amino acids increased label incorporation from (2-/sup 14/C) propionate into (/sup 14/C) glucose by 22%. Butyrate inhibited (2-/sup 14/C) propionate metabolism and increased the apparent Michaelis constant for (2-/sup 14/C) propionate incorporation into (/sup 14/C) glucose from 2.4 +/- 1.5 to 5.6 +/- .9 mM. Butyrate's effectsmore » on propionate were similar in the presence and absence of L-carnitine (1 mM). Isobutyrate, 2-methylbutyrate, and valerate (1.25 mM) had no effect on (/sup 14/C) glucose production but decreased /sup 14/CO/sub 2/ production to 57, 61, and 54% of the control (2-/sup 14/C) propionate (1.25 mM). This inhibition on /sup 14/CO/sub 2/ was not competitive. Isovalerate had no effect on either (2-/sup 14/C) propionate incorporation into glucose of CO/sub 2/. An increase in ratio of (/sup 14/C) glucose to /sup 14/CO/sub 2/ from (2-/sup 14/C)-propionate demonstrated that short-chain fatty acids other than butyrate do not inhibit gluconeogenesis from propionate. In addition, fatty acids that generate a net synthesis of intracellular oxaloacetate may partition propionate carbons toward gluconeogenic rather than oxidative pathways in goat hepatocytes.« less

  4. Isolation and characterization of bacterium producing lipid from short-chain fatty acids.

    PubMed

    Okamura, Yoshiko; Nakai, Shota; Ohkawachi, Masahiko; Suemitsu, Masahiro; Takahashi, Hirokazu; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Nakashimada, Yutaka; Matsumoto, Mitsufumi

    2016-02-01

    Anaerobic fermentation generates propionic acid, which inhibits microbial growth and accumulates in wastewater containing increased amounts of organic matter. We therefore isolated a propionic acid-assimilating bacterium that could produce triacylglycerol, for use in wastewater treatment. Nitratireductor sp. strain OM-1 can proliferate in medium containing propionic, acetic, butyric, and valeric acids as well as glycerol, and produces triacylglycerol when both propionic and acetic acids or glycerol are present. In composite model wastewater containing acetic acid, propionic acid and glycerol, this strain shows an even higher conversion rate, suggesting that it is suitable for wastewater treatment. Further, nitrogen depletion in medium containing an acetic-propionic acid mixture resulted in the production of the light oil 2-butenoic acid 1-methylethyl ester, but not triacylglycerol. Collectively, our data indicate that strain OM-1 has the potential to reduce accumulation of activated sludge in wastewater treatment and may contribute to the production of biodiesel. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Phylogenetic distribution of three pathways for propionate production within the human gut microbiota

    PubMed Central

    Reichardt, Nicole; Duncan, Sylvia H; Young, Pauline; Belenguer, Alvaro; McWilliam Leitch, Carol; Scott, Karen P; Flint, Harry J; Louis, Petra

    2014-01-01

    Propionate is produced in the human large intestine by microbial fermentation and may help maintain human health. We have examined the distribution of three different pathways used by bacteria for propionate formation using genomic and metagenomic analysis of the human gut microbiota and by designing degenerate primer sets for the detection of diagnostic genes for these pathways. Degenerate primers for the acrylate pathway (detecting the lcdA gene, encoding lactoyl-CoA dehydratase) together with metagenomic mining revealed that this pathway is restricted to only a few human colonic species within the Lachnospiraceae and Negativicutes. The operation of this pathway for lactate utilisation in Coprococcus catus (Lachnospiraceae) was confirmed using stable isotope labelling. The propanediol pathway that processes deoxy sugars such as fucose and rhamnose was more abundant within the Lachnospiraceae (based on the pduP gene, which encodes propionaldehyde dehydrogenase), occurring in relatives of Ruminococcus obeum and in Roseburia inulinivorans. The dominant source of propionate from hexose sugars, however, was concluded to be the succinate pathway, as indicated by the widespread distribution of the mmdA gene that encodes methylmalonyl-CoA decarboxylase in the Bacteroidetes and in many Negativicutes. In general, the capacity to produce propionate or butyrate from hexose sugars resided in different species, although two species of Lachnospiraceae (C. catus and R. inulinivorans) are now known to be able to switch from butyrate to propionate production on different substrates. A better understanding of the microbial ecology of short-chain fatty acid formation may allow modulation of propionate formation by the human gut microbiota. PMID:24553467

  6. City sewer collectors biocorrosion

    NASA Astrophysics Data System (ADS)

    Ksiażek, Mariusz

    2014-12-01

    This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

  7. Penetration of theophylline and adenosine into excised human skin from binary and ternary vehicles: effect of a nonionic surfactant.

    PubMed

    Kadir, R; Stempler, D; Liron, Z; Cohen, S

    1989-02-01

    A nonionic surfactant, diethyleneglycol lauryl ether (PEG-2-L), increases the flux of either theophylline or adenosine by a factor of 2.2-2.7, when these are delivered from propionic acid solutions into human skin samples, with respect to propionic acid alone. At the same time, the flux of propionic acid from the same vehicles is decreased. Significant expansion of the partial molal volumes vi of both purines occurs following incorporation of PEG-2-L into their propionic acid solution. Hence, the enhancing effect of this surfactant arises mainly from an increase in the excess free energy of these solutes in the donor phase ("push" effect). Paraffin oil increases the flux of either drug from propionic acid by an entirely different mechanism. It enhances the flux of propionic acid into the skin, thus promoting the partitioning of the purine solute in the modified skin barrier ("pull" effect). Indeed, the magnitude of vi of either purine in propionic acid:paraffin oil solution gives no indication of a significant interaction between paraffin oil and the purine solute. Finally, the penetration enhancing effects of PEG-2-L and paraffin oil combined together in the same propionic acid vehicle are additive, resulting in a flux which is approximately the sum total of fluxes obtained separately with PEG-2-L or paraffin oil.

  8. Autism: Metabolism, Mitochondria, and the Microbiome

    PubMed Central

    2013-01-01

    New approaches are needed to examine the diverse symptoms and comorbidities of the growing family of neurodevelopmental disorders known as autism spectrum disorder (ASD). ASD originally was thought to be a static, inheritable neurodevelopmental disorder, and our understanding of it is undergoing a major shift. It is emerging as a dynamic system of metabolic and immune anomalies involving many organ systems, including the brain, and environmental exposure. The initial detailed observation and inquiry of patients with ASD and related conditions and the histories of their caregivers and families have been invaluable. How gastrointestinal (GI) factors are related to ASD is not yet clear. Nevertheless, many patients with ASD have a history of previous antibiotic exposure or hospitalization, GI symptoms, abnormal food cravings, and unique intestinal bacterial populations, which have been proposed to relate to variable symptom severity. In addition to traditional scientific inquiry, detailed clinical observation and recording of exacerbations, remissions, and comorbidities are needed. This article reviews the role that enteric short-chain fatty acids, particularly propionic (also called propanoic) acid, produced from ASD-associated GI bacteria, may play in the etiology of some forms of ASD. Human populations that are partial metabolizers of propionic acid are more common than previously thought. The results from pre-clinical laboratory studies show that propionic acid-treated rats display ASD-like repetitive, perseverative, and antisocial behaviors and seizure. Neurochemical changes, consistent and predictive with findings in ASD patients, including neuroinflammation, increased oxidative stress, mitochondrial dysfunction, glutathione depletion, and altered phospholipid/acylcarnitine profiles, have been observed. Propionic acid has bioactive effects on (1) neurotransmitter systems, (2) intracellular acidification and calcium release, (3) fatty acid metabolism, (4) gap junction gating, (5) immune function, and (6) alteration of gene expression that warrant further exploration. Traditional scientific experimentation is needed to verify the hypothesis that enteric short-chain fatty acids may be a potential environmental trigger in some forms of ASD. Novel collaborative developments in systems biology, particularly examining the role of the microbiome and its effects on host metabolism, immune and mitochondrial function, and gene expression, hold great promise in ASD. PMID:24416709

  9. Conductive iron oxides accelerate thermophilic methanogenesis from acetate and propionate.

    PubMed

    Yamada, Chihaya; Kato, Souichiro; Ueno, Yoshiyuki; Ishii, Masaharu; Igarashi, Yasuo

    2015-06-01

    Anaerobic digester is one of the attractive technologies for treatment of organic wastes and wastewater, while continuous development and improvements on their stable operation with efficient organic removal are required. Particles of conductive iron oxides (e.g., magnetite) are known to facilitate microbial interspecies electron transfer (termed as electric syntrophy). Electric syntrophy has been reported to enhance methanogenic degradation of organic acids by mesophilic communities in soil and anaerobic digester. Here we investigated the effects of supplementation of conductive iron oxides (magnetite) on thermophilic methanogenic microbial communities derived from a thermophilic anaerobic digester. Supplementation of magnetite accelerated methanogenesis from acetate and propionate under thermophilic conditions, while supplementation of ferrihydrite also accelerated methanogenesis from propionate. Microbial community analysis revealed that supplementation of magnetite drastically changed bacterial populations in the methanogenic acetate-degrading cultures, in which Tepidoanaerobacter sp. and Coprothermobacter sp. dominated. These results suggest that supplementation of magnetite induce electric syntrophy between organic acid-oxidizing bacteria and methanogenic archaea and accelerate methanogenesis even under thermophilic conditions. Findings from this study would provide a possibility for the achievement of stably operating thermophilic anaerobic digestion systems with high efficiency for removal of organics and generation of CH4. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. Awakening sleeping beauty: production of propionic acid in Escherichia coli through the sbm operon requires the activity of a methylmalonyl-CoA epimerase.

    PubMed

    Gonzalez-Garcia, Ricardo Axayacatl; McCubbin, Tim; Wille, Annalena; Plan, Manuel; Nielsen, Lars Keld; Marcellin, Esteban

    2017-07-17

    Propionic acid is used primarily as a food preservative with smaller applications as a chemical building block for the production of many products including fabrics, cosmetics, drugs, and plastics. Biological production using propionibacteria would be competitive against chemical production through hydrocarboxylation of ethylene if native producers could be engineered to reach near-theoretical yield and good productivity. Unfortunately, engineering propionibacteria has proven very challenging. It has been suggested that activation of the sleeping beauty operon in Escherichia coli is sufficient to achieve propionic acid production. Optimising E. coli production should be much easier than engineering propionibacteria if tolerance issues can be addressed. Propionic acid is produced in E. coli via the sleeping beauty mutase operon under anaerobic conditions in rich medium via amino acid degradation. We observed that the sbm operon enhances amino acids degradation to propionic acid and allows E. coli to degrade isoleucine. However, we show here that the operon lacks an epimerase reaction that enables propionic acid production in minimal medium containing glucose as the sole carbon source. Production from glucose can be restored by engineering the system with a methylmalonyl-CoA epimerase from Propionibacterium acidipropionici (0.23 ± 0.02 mM). 1-Propanol production was also detected from the promiscuous activity of the native alcohol dehydrogenase (AdhE). We also show that aerobic conditions are favourable for propionic acid production. Finally, we increase titre 65 times using a combination of promoter engineering and process optimisation. The native sbm operon encodes an incomplete pathway. Production of propionic acid from glucose as sole carbon source is possible when the pathway is complemented with a methylmalonyl-CoA epimerase. Although propionic acid via the restored succinate dissimilation pathway is considered a fermentative process, the engineered pathway was shown to be functional under anaerobic and aerobic conditions.

  11. Generation of volatile fatty acids by axillary bacteria.

    PubMed

    James, A G; Hyliands, D; Johnston, H

    2004-06-01

    It is generally accepted that short-chain (C(2)-C(5)) volatile fatty acids (VFAs) are among the causal molecules of axillary malodour. It is also widely acknowledged that malodour generation is attributable to the biotransformation of odourless natural secretions, into volatile odorous products, by axillary bacteria. However, little information is available on the biochemical origins of VFAs on axillary skin. In these studies, assay systems were developed to investigate the generation of VFAs from substrates readily available to the bacteria resident on axillary skin. Propionibacteria and staphylococci were shown to ferment glycerol and lactic acid to the short-chain (C(2)-C(3)) VFAs, acetic and propionic acid. Furthermore, staphylococci are capable of converting branched aliphatic amino acids, such as leucine, to highly odorous short-chain (C(4)-C(5)) methyl-branched VFAs, such as isovaleric acid, which are traditionally associated with the acidic note of axillary malodour. However, in vitro kinetic data indicates that these pathways contribute less to axillary VFA levels, than fatty acid biotransformations by a recently defined sub-group of the Corynebacterium genus, corynebacteria (A). The results of these studies provide new understanding on the biochemical origins of VFA-based axillary malodour which, in turn, should lead to the development of novel deodorant systems.

  12. THE PRODUCTION OF VOLATILE FATTY ACIDS BY BACTERIA OF THE DYSENTERY GROUP

    PubMed Central

    Zoller, Harper F.; Clark, W. Mansfield

    1921-01-01

    These studies show: 1. A close agreement exists among all the organisms studied in the total quantity of volatile fatty acids produced and in the ratio of formic to acetic, under aerobic conditions, and in the presence of 1 per cent of glucose. 2. When grown upon peptone alone, with free access of air to the cultures, volatile fatty acids are produced in appreciable quantities, although the reaction of the solution has gone more alkaline as shown by colorimetric pH tests. Formic acid is not found, but in its place we obtain propionic acid. 3. Upon exhaustion of air from the non-sugar medium the bacteria again produce formic acid, and in addition some butyric. This is true for both Shiga and non-Shiga cultures. The reaction is distinctly more acid. 4. The presence of glucose in the medium from which the air has been pumped furnishes a condition which provokes about the same type and degree of fermentation that operates in the glucose medium bathed in air at atmospheric pressure. 5. The enormous quantity of formic acid produced by these bacteria may play a significant part in the digestive disturbances and toxic symptoms accompanying their infection of the human intestinal tract. PMID:19871867

  13. Propionic acid and butyric acid inhibit lipolysis and de novo lipogenesis and increase insulin-stimulated glucose uptake in primary rat adipocytes

    PubMed Central

    Heimann, Emilia; Nyman, Margareta; Degerman, Eva

    2014-01-01

    Fermentation of dietary fibers by colonic microbiota generates short-chain fatty acids (SCFAs), e.g., propionic acid and butyric acid, which have been described to have “anti-obesity properties” by ameliorating fasting glycaemia, body weight and insulin tolerance in animal models. In the present study, we therefore investigate if propionic acid and butyric acid have effects on lipolysis, de novo lipogenesis and glucose uptake in primary rat adipocytes. We show that both propionic acid and butyric acid inhibit isoproterenol- and adenosine deaminase-stimulated lipolysis as well as isoproterenol-stimulated lipolysis in the presence of a phosphodiesterase (PDE3) inhibitor. In addition, we show that propionic acid and butyric acid inhibit basal and insulin-stimulated de novo lipogenesis, which is associated with increased phosphorylation and thus inhibition of acetyl CoA carboxylase, a rate-limiting enzyme in fatty acid synthesis. Furthermore, we show that propionic acid and butyric acid increase insulin-stimulated glucose uptake. To conclude, our study shows that SCFAs have effects on fat storage and mobilization as well as glucose uptake in rat primary adipocytes. Thus, the SCFAs might contribute to healthier adipocytes and subsequently also to improved energy metabolism with for example less circulating free fatty acids, which is beneficial in the context of obesity and type 2 diabetes. PMID:26167409

  14. Propionic acid and butyric acid inhibit lipolysis and de novo lipogenesis and increase insulin-stimulated glucose uptake in primary rat adipocytes.

    PubMed

    Heimann, Emilia; Nyman, Margareta; Degerman, Eva

    2015-01-01

    Fermentation of dietary fibers by colonic microbiota generates short-chain fatty acids (SCFAs), e.g., propionic acid and butyric acid, which have been described to have "anti-obesity properties" by ameliorating fasting glycaemia, body weight and insulin tolerance in animal models. In the present study, we therefore investigate if propionic acid and butyric acid have effects on lipolysis, de novo lipogenesis and glucose uptake in primary rat adipocytes. We show that both propionic acid and butyric acid inhibit isoproterenol- and adenosine deaminase-stimulated lipolysis as well as isoproterenol-stimulated lipolysis in the presence of a phosphodiesterase (PDE3) inhibitor. In addition, we show that propionic acid and butyric acid inhibit basal and insulin-stimulated de novo lipogenesis, which is associated with increased phosphorylation and thus inhibition of acetyl CoA carboxylase, a rate-limiting enzyme in fatty acid synthesis. Furthermore, we show that propionic acid and butyric acid increase insulin-stimulated glucose uptake. To conclude, our study shows that SCFAs have effects on fat storage and mobilization as well as glucose uptake in rat primary adipocytes. Thus, the SCFAs might contribute to healthier adipocytes and subsequently also to improved energy metabolism with for example less circulating free fatty acids, which is beneficial in the context of obesity and type 2 diabetes.

  15. Cysteine-Accelerated Methanogenic Propionate Degradation in Paddy Soil Enrichment.

    PubMed

    Zhuang, Li; Ma, Jinlian; Tang, Jia; Tang, Ziyang; Zhou, Shungui

    2017-05-01

    Propionate degradation is a critical step during the conversion of complex organic matter under methanogenic conditions, and it requires a syntrophic cooperation between propionate-oxidizing bacteria and methanogenic archaea. Increasing evidences suggest that interspecies electron transfer for syntrophic metabolism is not limited to the reducing equivalents of hydrogen and formate. This study tested the ability of an electron shuttle to mediate interspecies electron transfer in syntrophic methanogenesis. We found that cysteine supplementation (100, 400, and 800 μM) accelerated CH 4 production from propionate in paddy soil enrichments. Of the concentrations tested, 100 μM cysteine was the most effective at enhancing propionate degradation to CH 4 , and the rates of CH 4 production and propionate degradation were increased by 109 and 79%, respectively, compared with the cysteine-free control incubations. We eliminated the possibility that the stimulatory effect of cysteine on methanogenesis was attributable to the function of cysteine as a methanogenic substrate in the presence of propionate. The potential catalytic effect involved cysteine serving as an electron carrier to mediate interspecies electron transfer in syntrophic propionate oxidization. The redox potential of cystine/cysteine, which is dependent on the concentration, might be more suitable to facilitate interspecies electron transfer between syntrophic partners at a concentration of 100 μM. Pelotomaculum, obligately syntrophic, propionate-oxidizing bacteria, and hydrogenotrophic methanogens of the family Methanobacteriaceae are predominant in cysteine-mediated methanogenic propionate degradation. The stimulatory effect of cysteine on syntrophic methanogenesis offers remarkable potential for improving the performance of anaerobic digestion and conceptually broaden strategies for interspecies electron transfer in syntrophic metabolism.

  16. [Antimutagenic action of superoxide dismutase on sodium azide- and nitrosoguanidine-induced mutagenesis in Salmonella typhimurium TA 1535].

    PubMed

    Vorob'eva, L I; Cherdyntseva, T A; Aver'ianov, A A; Abilev, S K

    1993-05-01

    It was shown that superoxide dismutase (SOD) decreased the mutagenic action of sodium azide (NaN3) and N-methyl-N'-nitro-N-nitrosoguanidine in Salmonella typhimurium TA1535. Catalase and quenchers of hydroxyl radicals showed, unlike SOD no effect on the mutagenicity of NaN3. Cell extract from propionic acid bacteria also possessed the antimutagenic activity, only partially depending on the SOD activity.

  17. Effect of some Evaporation Matters on Storability of Sunflower ( Helianthus annuus L.) Seed.

    PubMed

    El-Saidy, Aml E A; El-Hai, K M Abd

    This study focuses on finding compounds that are safe to humans and environment, such as propionic and acetic acids that may provide an alternative control of seed-borne pathogens and decrease seed deterioration during storage. The objectives of this study were to reduce sunflower seed deterioration and improve the viability of sunflower seed using environmentally safe organic acids. Propionic and acetic acids were applied on sunflower seed at different concentrations under laboratory conditions during different storage periods. After 6 months storage period, the viability of sunflower seed as well as morphological and physiological characteristics of seedlings were evaluated under greenhouse conditions. Laboratory experiment was conducted in a factorial completely randomized design and randomized complete block design for greenhouse experiment. Propionic and acetic acids at different concentrations showed inhibitory effects on the presence of different fungal genera in all storage periods. Propionic acid was most effective followed by acetic acid. Increasing storage periods from 0-6 months significantly decreased germination percentage, germination energy, seedling characters, survived healthy seedlings and seed oil and protein percentages but dead and rotted seeds, as well as rotted seedlings were increased. Treating sunflower seeds with propionic acid (100%) improved germination criteria, seedling characters and seed chemical characters as well as survival seedlings and minimized the dead seeds, rotted seeds and rotted seedlings as compared with the control under all storage periods. Under greenhouse conditions, the maximum growth parameter and physiological characters (chlorophylls a, b, carotenoids and total phenols) were recorded from seed treated with 100% propionic acid after 6 months of storage. It may be concluded that propionic and acetic acids vapors can have considerable fungicidal activity against sunflower pathogens and improve seed viability. Therefore, it is recommended using 100% propionic acid to reduce deterioration and seed-borne pathogens of sunflower under storage conditions.

  18. Inhibitory Effect of Autoclaving Whey-Based Medium on Propionic Acid Production by Propionibacterium shermanii.

    PubMed

    Anderson, T M; Bodie, E A; Goodman, N; Schwartz, R D

    1986-02-01

    Propionic acid production by Propionibacterium shermanii was compared in pasteurized and autoclaved whey-based media. Propionic acid production decreased with increasing whey concentration in autoclaved media but not in pasteurized media. Increasing the yeast extract concentration from 5 to 10 g/liter greatly reduced the inhibitory effect of autoclaving.

  19. Community analysis of a full-scale anaerobic bioreactor treating paper mill wastewater.

    PubMed

    Roest, Kees; Heilig, Hans G H J; Smidt, Hauke; de Vos, Willem M; Stams, Alfons J M; Akkermans, Antoon D L

    2005-03-01

    To get insight into the microbial community of an Upflow Anaerobic Sludge Blanket reactor treating paper mill wastewater, conventional microbiological methods were combined with 16S rRNA gene analyses. Particular attention was paid to microorganisms able to degrade propionate or butyrate in the presence or absence of sulphate. Serial enrichment dilutions allowed estimating the number of microorganisms per ml sludge that could use butyrate with or without sulphate (10(5)), propionate without sulphate (10(6)), or propionate and sulphate (10(8)). Quantitative RNA dot-blot hybridisation indicated that Archaea were two-times more abundant in the microbial community of anaerobic sludge than Bacteria. The microbial community composition was further characterised by 16S rRNA-gene-targeted Denaturing Gradient Gel Electrophoresis (DGGE) fingerprinting, and via cloning and sequencing of dominant amplicons from the bacterial and archaeal patterns. Most of the nearly full length (approximately 1.45 kb) bacterial 16S rRNA gene sequences showed less than 97% similarity to sequences present in public databases, in contrast to the archaeal clones (approximately. 1.3 kb) that were highly similar to known sequences. While Methanosaeta was found as the most abundant genus, also Crenarchaeote-relatives were identified. The microbial community was relatively stable over a period of 3 years (samples taken in July 1999, May 2001, March 2002 and June 2002) as indicated by the high similarity index calculated from DGGE profiles (81.9+/-2.7% for Bacteria and 75.1+/-3.1% for Archaea). 16S rRNA gene sequence analysis indicated the presence of unknown and yet uncultured microorganisms, but also showed that known sulphate-reducing bacteria and syntrophic fatty acid-oxidising microorganisms dominated the enrichments.

  20. Inhibitory Effect of Autoclaving Whey-Based Medium on Propionic Acid Production by Propionibacterium shermanii

    PubMed Central

    Anderson, Thomas M.; Bodie, Elizabeth A.; Goodman, Nelson; Schwartz, Robert D.

    1986-01-01

    Propionic acid production by Propionibacterium shermanii was compared in pasteurized and autoclaved whey-based media. Propionic acid production decreased with increasing whey concentration in autoclaved media but not in pasteurized media. Increasing the yeast extract concentration from 5 to 10 g/liter greatly reduced the inhibitory effect of autoclaving. PMID:16346998

  1. [Anaerobic biodegradation of phthalic acid esters (Paes) in municipal sludge].

    PubMed

    Liang, Zhi-Feng; Zhou, Wen; Lin, Qing-Qi; Yang, Xiu-Hong; Wang, Shi-Zhong; Cai, Xin-De; Qiu, Rong-Liang

    2014-04-01

    Phthalic acid esters (PAEs), a class of organic pollutants with potent endocrine-disrupting properties, are widely present in municipal sludge. Study of PAEs biodegradation under different anaerobic biological treatment processes of sludge is, therefore, essential for a safe use of sludge in agricultural practice. In this study, we selected two major sludge PAEs, i.e. di-n-butyl phthalate (DBP) and di-(2-enthylhexyl) phthalate (DEHP), to investigate their biodegradation behaviors in an anaerobic sludge digestion system and a fermentative hydrogen production system. The possible factors influencing PAEs biodegradation in relation to changes of sludge properties were also discussed. The results showed that the biodegradation of DBP reached 99.6% within 6 days, while that of DEHP was 46.1% during a 14-day incubation period in the anaerobic digestion system. By comparison, only 19.5% of DBP was degraded within 14 days in the fermentative hydrogen production system, while no degradation was detected for DEHP. The strong inhibition of the degradation of both PAEs in the fermentative hydrogen production system was ascribed to the decreases in microbial biomass and ratios of gram-positive bacteria/gram-negative bacteria and fungi/ bacteria, and the increase of concentrations of volatile fatty acids (e. g. acetic acid, propionic acid and butyric acid) during the fermentative hydrogen-producing process.

  2. [Process development for continuous ethanol fermentation by the flocculating yeast under stillage backset conditions].

    PubMed

    Zi, Lihan; Liu, Chenguang; Bai, Fengwu

    2014-02-01

    Propionic acid, a major inhibitor to yeast cells, was accumulated during continuous ethanol fermentation from corn meal hydrolysate by the flocculating yeast under stillage backset conditions. Based on its inhibition mechanism in yeast cells, strategies were developed for alleviating this effect. Firstly, high temperature processes such as medium sterilization generated more propionic acid, which should be avoided. Propionic acid was reduced significantly during ethanol fermentation without medium sterilization, and concentrations of biomass and ethanol increased by 59.3% and 7.4%, respectively. Secondly, the running time of stillage backset should be controlled so that propionic acid accumulated would be lower than its half inhibition concentration IC50 (40 mmol/L). Finally, because low pH augmented propionic acid inhibition in yeast cells, a higher pH of 5.5 was validated to be suitable for ethanol fermentation under the stillage backset condition.

  3. Odd-chain fatty acids as a biomarker for dietary fiber intake: a novel pathway for endogenous production from propionate.

    PubMed

    Weitkunat, Karolin; Schumann, Sara; Nickel, Daniela; Hornemann, Silke; Petzke, Klaus J; Schulze, Matthias B; Pfeiffer, Andreas Fh; Klaus, Susanne

    2017-06-01

    Background: The risk of type 2 diabetes is inversely correlated with plasma concentrations of odd-chain fatty acids [OCFAs; pentadecanoic acid (15:0) and heptadecanoic acid (17:0)], which are considered as biomarkers for dairy fat intake in humans. However, rodent studies suggest that OCFAs are synthesized endogenously from gut-derived propionate. Propionate increases with dietary fiber consumption and has been shown to improve insulin sensitivity. Objective: We hypothesized that OCFAs are produced in humans from dietary fibers by a novel endogenous pathway. Design: In a randomized, double-blind crossover study, 16 healthy individuals were supplemented with cellulose (30 g/d), inulin (30 g/d), or propionate (6 g/d) for 7 d. In addition, human hepatoma cells were incubated with different propionate concentrations. OCFAs were determined in plasma phospholipids and hepatoma cells by gas chromatography. Results: Cellulose did not affect plasma OCFA levels, whereas inulin and propionate increased pentadecanoic acid by ∼17% ( P < 0.05) and 13% ( P = 0.05), respectively. The effect on heptadecanoic acid was even more pronounced, because it was elevated in almost all participants by inulin (11%; P < 0.01) and propionate (13%; P < 0.001). Furthermore, cell culture experiments showed a positive association between propionate and OCFA levels ( R 2 = 0.99, P < 0.0001), whereas palmitate (16:0) was negatively correlated ( R 2 = 0.83, P = 0.004). Conclusions: Our data show that gut-derived propionate is used for the hepatic synthesis of OCFAs in humans. The association of OCFAs with a decreased risk of type 2 diabetes may therefore also relate to dietary fiber intake and not only dairy fat. This trial was registered at www.germanctr.de as DRKS00010121. © 2017 American Society for Nutrition.

  4. Surface-enhanced Raman spectroscopic monitor of triglyceride hydrolysis in a skin pore phantom

    NASA Astrophysics Data System (ADS)

    Weldon, Millicent K.; Morris, Michael D.

    1999-04-01

    Bacterial hydrolysis of triglycerides is followed in a sebum probe phantom by microprobe surface-enhanced Raman scattering (SERS) spectroscopy. The phantom consists of a purpose-built syringe pump operating at physiological flow rates connected to a 300 micron i.d. capillary. We employ silicon substrate SERS microprobes to monitor the hydrolysis products. The silicon support allows some tip flexibility that makes these probes ideal for insertion into small structures. Propionibacterium acnes are immobilized on the inner surface of the capillary. These bacteria hydrolyze the triglycerides in a model sebum emulsion flowing through the capillary. The transformation is followed in vitro as changes in the SERS caused by hydrolysis of triglyceride to fatty acid. The breakdown products consists of a mixture of mono- and diglycerides and their parent long chain fatty acids. The fatty acids adsorb as their carboxylates and can be readily identified by their characteristic spectra. The technique can also confirm the presence of bacteria by detection of short chain carboxylic acids released as products of glucose fermentation during the growth cycle of these cells. Co-adsorption of propionate is observed. Spatial localization of the bacteria is obtained by ex-situ line imaging of the probe.

  5. Enzymatic polymerization of natural anacardic acid and antibiofouling effects of polyanacardic acid coatings.

    PubMed

    Chelikani, Rahul; Kim, Yong Hwan; Yoon, Do-Young; Kim, Dong-Shik

    2009-05-01

    Anacardic acid, separated from cashew nut shell liquid, is well known for its strong antibiotic and antioxidant activities. Recent findings indicate that phenolic compounds from plant sources have an effect on Gram-negative bacteria biofilm formation. In this work, a polyphenolic coating was prepared from anacardic acid using enzymatic synthesis and tested for its effects on biofilm formation of both Gram-negative and Gram-positive bacteria. Natural anacardic acid was enzymatically polymerized using soybean peroxidase. Hydrogen peroxide and phenothiazine-10-propionic acid were used as an oxidizing agent and redox mediator, respectively. Nuclear magnetic resonance and Fourier transform infrared (FTIR) analyses showed the formation of oxyphenylene and phenylene units through the phenol rings. No linkage through the alkyl chain was observed, which proved a high chemo-selectivity of the enzyme. Aqueous solvents turned out to play an important role in the polymer production yield and molecular weight. With 2-propanol, the highest production yield (61%) of polymer (molecular weight = 3,900) was observed, and with methanol, higher-molecular-weight polymers (5,000) were produced with lower production yields (43%). The resulting polyanacardic acid was cross-linked on a solid surface to form a permanent natural polymer coating. The FTIR analysis indicates that the cross-linking between the polymers took place through the unsaturated alkyl side chains. The polyanacardic acid coating was then tested for its antibiofouling effect against Gram-negative and Gram-positive bacteria and compared with the antibiofouling effects of polycardanol coatings reported in the literature. The polyanacardic acid coating showed more reduction in biofilm formation on its surface than polycardanol coatings in the case of Gram-positive bacteria, while in the case of Gram-negative bacteria, it showed a similar reduction in biofilm formation as polycardanol.

  6. Methionine catabolism and production of volatile sulphur compounds by OEnococcus oeni.

    PubMed

    Pripis-Nicolau, L; de Revel, G; Bertrand, A; Lonvaud-Funel, A

    2004-01-01

    During malolactic fermentation (MLF), the secondary metabolisms of lactic acid bacteria (LAB) contribute to the organoleptic modification of wine. To understand the contribution of MLF, we evaluated the capacity of various wine LAB to metabolize methionine. Using gas chromatography (GC) coupled either with mass spectrometry (MS) or a flame photometry detector in sulphur mode (FPD), we studied this metabolism in laboratory media and wine. In laboratory media, several LAB isolated from wine were able to metabolize methionine. They formed methanethiol, dimethyl disulphide, 3-(methylsulphanyl)propan-1-ol and 3-(methylsulphanyl)propionic acid. These are known to have powerful characteristic odours and play a role in the aromatic complexity of wine. In various red wines, after MLF only the 3-(methylsulphanyl)propionic acid concentration increased significantly, as verified with several commercial starter cultures. This compound, which is characterized by chocolate and roasted odours, could contribute to the aromatic complexity produced by MLF. This study shows that LAB isolated from wine, especially OEnococcus oeni strains, the major species in MLF, are able to metabolize methionine to form volatile sulphur compounds. This is the first study to demonstrate the capacity of wine LAB to metabolize methionine.

  7. Genome-scale model guided design of Propionibacterium for enhanced propionic acid production.

    PubMed

    Navone, Laura; McCubbin, Tim; Gonzalez-Garcia, Ricardo A; Nielsen, Lars K; Marcellin, Esteban

    2018-06-01

    Production of propionic acid by fermentation of propionibacteria has gained increasing attention in the past few years. However, biomanufacturing of propionic acid cannot compete with the current oxo-petrochemical synthesis process due to its well-established infrastructure, low oil prices and the high downstream purification costs of microbial production. Strain improvement to increase propionic acid yield is the best alternative to reduce downstream purification costs. The recent generation of genome-scale models for a number of Propionibacterium species facilitates the rational design of metabolic engineering strategies and provides a new opportunity to explore the metabolic potential of the Wood-Werkman cycle. Previous strategies for strain improvement have individually targeted acid tolerance, rate of propionate production or minimisation of by-products. Here we used the P. freudenreichii subsp . shermanii and the pan- Propionibacterium genome-scale metabolic models (GEMs) to simultaneously target these combined issues. This was achieved by focussing on strategies which yield higher energies and directly suppress acetate formation. Using P. freudenreichii subsp . shermanii , two strategies were assessed. The first tested the ability to manipulate the redox balance to favour propionate production by over-expressing the first two enzymes of the pentose-phosphate pathway (PPP), Zwf (glucose-6-phosphate 1-dehydrogenase) and Pgl (6-phosphogluconolactonase). Results showed a 4-fold increase in propionate to acetate ratio during the exponential growth phase. Secondly, the ability to enhance the energy yield from propionate production by over-expressing an ATP-dependent phosphoenolpyruvate carboxykinase (PEPCK) and sodium-pumping methylmalonyl-CoA decarboxylase (MMD) was tested, which extended the exponential growth phase. Together, these strategies demonstrate that in silico design strategies are predictive and can be used to reduce by-product formation in Propionibacterium . We also describe the benefit of carbon dioxide to propionibacteria growth, substrate conversion and propionate yield.

  8. Long-term high-solids anaerobic digestion of food waste: Effects of ammonia on process performance and microbial community.

    PubMed

    Peng, Xuya; Zhang, ShangYi; Li, Lei; Zhao, Xiaofei; Ma, Yao; Shi, Dezhi

    2018-04-22

    A long-term high solids anaerobic digestion of food waste was conducted to identify microbial mechanisms of ammonia inhibition during digestion and to clarify correlations between ammonia accumulation, microbial community dynamics (diversity, composition, and interactions), and process stability. Results show that the effects of ammonia on process performance and microbial community were indirectly caused by volatile fatty acid accumulation. Excess free ammonia blocked acetate metabolism, leading to process instability. Accumulated acetate caused feedback inhibition at the acetogenesis stage, which resulted in considerable accumulation of propionate, valerate, and other long-chain fatty acids. This high concentration of volatile fatty acids reduced the abundance of syntrophic acetogenic bacteria and allowed hydrolytic fermentative bacteria to dominate. The normally interactive and orderly metabolic network was broken, which further exacerbated the process instability. These results improve the understanding of microbial mechanisms which contribute to process instability and provide guidance for the microbial management of anaerobic digesters. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Use of a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin column and propionic acid as an eluent in ion-exclusion/adsorption chromatography of aliphatic carboxylic acids and ethanol in food samples.

    PubMed

    Mori, Masanobu; Hironaga, Takahiro; Kajiwara, Hiroe; Nakatani, Nobutake; Kozaki, Daisuke; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2011-01-01

    We developed an ion-exclusion/adsorption chromatography (IEAC) method employing a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin (PS-WCX) column with propionic acid as the eluent for the simultaneous determination of multivalent aliphatic carboxylic acids and ethanol in food samples. The PS-WCX column well resolved mono-, di-, and trivalent carboxylic acids in the acidic eluent. Propionic acid as the eluent gave a higher signal-to-noise ratio, and enabled sensitive conductimetric detection of analyte acids. We found the optimal separation condition to be the combination of a PS-WCX column and 20-mM propionic acid. Practical applicability of the developed method was confirmed by using a short precolumn with a strongly acidic cation-exchange resin in the H(+)-form connected before the separation column; this was to remove cations from food samples by converting them to hydrogen ions. Consequently, common carboxylic acids and ethanol in beer, wine, and soy sauce were successfully separated by the developed method.

  10. 21 CFR 184.1221 - Calcium propionate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium propionate. 184.1221 Section 184.1221 Food... Specific Substances Affirmed as GRAS § 184.1221 Calcium propionate. (a) Calcium propionate (C6H10CaO4, CAS Reg. No. 4075-81-4) is the calcium salt of propionic acid. It occurs as white crystals or a...

  11. 21 CFR 184.1221 - Calcium propionate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium propionate. 184.1221 Section 184.1221 Food... Specific Substances Affirmed as GRAS § 184.1221 Calcium propionate. (a) Calcium propionate (C6H10CaO4, CAS Reg. No. 4075-81-4) is the calcium salt of propionic acid. It occurs as white crystals or a...

  12. 21 CFR 184.1784 - Sodium propionate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium propionate. 184.1784 Section 184.1784 Food... Specific Substances Affirmed as GRAS § 184.1784 Sodium propionate. (a) Sodium propionate (C3H5NaO2, CAS Reg. No. 137-40-6) is the sodium salt of propionic acid. It occurs as colorless, transparent crystals or a...

  13. 21 CFR 184.1784 - Sodium propionate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium propionate. 184.1784 Section 184.1784 Food... GRAS § 184.1784 Sodium propionate. (a) Sodium propionate (C3H5NaO2, CAS Reg. No. 137-40-6) is the sodium salt of propionic acid. It occurs as colorless, transparent crystals or a granular crystalline...

  14. 21 CFR 184.1784 - Sodium propionate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium propionate. 184.1784 Section 184.1784 Food... Specific Substances Affirmed as GRAS § 184.1784 Sodium propionate. (a) Sodium propionate (C3H5NaO2, CAS Reg. No. 137-40-6) is the sodium salt of propionic acid. It occurs as colorless, transparent crystals or a...

  15. 21 CFR 184.1784 - Sodium propionate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium propionate. 184.1784 Section 184.1784 Food... Specific Substances Affirmed as GRAS § 184.1784 Sodium propionate. (a) Sodium propionate (C3H5NaO2, CAS Reg. No. 137-40-6) is the sodium salt of propionic acid. It occurs as colorless, transparent crystals or a...

  16. 21 CFR 184.1784 - Sodium propionate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium propionate. 184.1784 Section 184.1784 Food... Specific Substances Affirmed as GRAS § 184.1784 Sodium propionate. (a) Sodium propionate (C3H5NaO2, CAS Reg. No. 137-40-6) is the sodium salt of propionic acid. It occurs as colorless, transparent crystals or a...

  17. 21 CFR 184.1221 - Calcium propionate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium propionate. 184.1221 Section 184.1221 Food... GRAS § 184.1221 Calcium propionate. (a) Calcium propionate (C6H10CaO4, CAS Reg. No. 4075-81-4) is the calcium salt of propionic acid. It occurs as white crystals or a crystalline solid, possessing not more...

  18. 21 CFR 184.1221 - Calcium propionate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium propionate. 184.1221 Section 184.1221 Food... Specific Substances Affirmed as GRAS § 184.1221 Calcium propionate. (a) Calcium propionate (C6H10CaO4, CAS Reg. No. 4075-81-4) is the calcium salt of propionic acid. It occurs as white crystals or a...

  19. 21 CFR 184.1221 - Calcium propionate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium propionate. 184.1221 Section 184.1221 Food... Specific Substances Affirmed as GRAS § 184.1221 Calcium propionate. (a) Calcium propionate (C6H10CaO4, CAS Reg. No. 4075-81-4) is the calcium salt of propionic acid. It occurs as white crystals or a...

  20. Acetate but not propionate induces oxidative stress in bakers' yeast Saccharomyces cerevisiae.

    PubMed

    Semchyshyn, Halyna M; Abrat, Oleksandra B; Miedzobrodzki, Jacek; Inoue, Yoshiharu; Lushchak, Volodymyr I

    2011-01-01

    The influence of acetic and propionic acids on baker's yeast was investigated in order to expand our understanding of the effect of weak organic acid food preservatives on eukaryotic cells. Both acids decreased yeast survival in a concentration-dependent manner, but with different efficiencies. The acids inhibited the fluorescein efflux from yeast cells. The inhibition constant of fluorescein extrusion from cells treated with acetate was significantly lower in parental strain than in either PDR12 (ABC-transporter Pdr12p) or WAR1 (transcriptional factor of Pdr12p) defective mutants. The constants of inhibition by propionate were virtually the same in all strains used. Yeast exposure to acetate increased the level of oxidized proteins and the activity of antioxidant enzymes, while propionate did not change these parameters. This suggests that various mechanisms underlie the yeast toxicity by acetic and propionic acids. Our studies with mutant cells clearly indicated the involvement of Yap1p transcriptional regulator and de novo protein synthesis in superoxide dismutase up-regulation by acetate. The up-regulation of catalase was Yap1p independent. Yeast pre-incubation with low concentrations of H₂O₂ caused cellular cross-protection against high concentrations of acetate. The results are discussed from the point of view that acetate induces a prooxidant effect in vivo, whereas propionate does not.

  1. Effects of carbon dioxide on cell growth and propionic acid production from glycerol and glucose by Propionibacterium acidipropionici.

    PubMed

    Zhang, An; Sun, Jianxin; Wang, Zhongqiang; Yang, Shang-Tian; Zhou, Haiying

    2015-01-01

    The effects of CO2 on propionic acid production and cell growth in glycerol or glucose fermentation were investigated in this study. In glycerol fermentation, the volumetric productivity of propionic acid with CO2 supplementation reached 2.94g/L/day, compared to 1.56g/L/day without CO2. The cell growth using glycerol was also significantly enhanced with CO2. In addition, the yield and productivity of succinate, the main intermediate in Wood-Werkman cycle, increased 81% and 280%, respectively; consistent with the increased activities of pyruvate carboxylase and propionyl CoA transferase, two key enzymes in the Wood-Werkman cycle. However, in glucose fermentation CO2 had minimal effect on propionic acid production and cell growth. The carbon flux distributions using glycerol or glucose were also analyzed using a stoichiometric metabolic model. The calculated maintenance coefficient (mATP) increased 100%, which may explain the increase in the productivity of propionic acid in glycerol fermentation with CO2 supplement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Accumulation of propionic acid during consecutive batch anaerobic digestion of commercial food waste.

    PubMed

    Capson-Tojo, Gabriel; Ruiz, Diane; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

    2017-12-01

    The objective of this study was to test three different alternatives to mitigate the destabilizing effect of accumulation of ammonia and volatile fatty acids during food waste anaerobic digestion. The three options tested (low temperature, co-digestion with paper waste and trace elements addition) were compared using consecutive batch reactors. Although methane was produced efficiently (∼500ml CH 4 gVS -1 ; 16l CH 4 lreactor -1 ), the concentrations of propionic acid increased gradually (up to 21.6gl -1 ). This caused lag phases in the methane production and eventually led to acidification at high substrate loads. The addition of trace elements improved the kinetics and allowed higher substrate loads, but could not avoid propionate accumulation. Here, it is shown for the first time that addition of activated carbon, trace elements and dilution can favor propionic acid consumption after its accumulation. These promising options should be optimized to prevent propionate accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Quantifying Effect of Lactic, Acetic, and Propionic Acids on Growth of Molds Isolated from Spoiled Bakery Products.

    PubMed

    Dagnas, Stéphane; Gauvry, Emilie; Onno, Bernard; Membré, Jeanne-Marie

    2015-09-01

    The combined effect of undissociated lactic acid (0 to 180 mmol/liter), acetic acid (0 to 60 mmol/liter), and propionic acid (0 to 12 mmol/liter) on growth of the molds Aspergillus niger, Penicillium corylophilum, and Eurotium repens was quantified at pH 3.8 and 25°C on malt extract agar acid medium. The impact of these acids on lag time for growth (λ) was quantified through a gamma model based on the MIC. The impact of these acids on radial growth rate (μ) was analyzed statistically through polynomial regression. Concerning λ, propionic acid exhibited a stronger inhibitory effect (MIC of 8 to 20 mmol/liter depending on the mold species) than did acetic acid (MIC of 23 to 72 mmol/liter). The lactic acid effect was null on E. repens and inhibitory on A. niger and P. corylophilum. These results were validated using independent sets of data for the three acids at pH 3.8 but for only acetic and propionic acids at pH 4.5. Concerning μ, the effect of acetic and propionic acids was slightly inhibitory for A. niger and P. corylophilum but was not significant for E. repens. In contrast, lactic acid promoted radial growth of all three molds. The gamma terms developed here for these acids will be incorporated in a predictive model for temperature, water activity, and acid. More generally, results for μ and λ will be used to identify and evaluate solutions for controlling bakery product spoilage.

  4. Antifungal activity of strains of lactic acid bacteria isolated from a semolina ecosystem against Penicillium roqueforti, Aspergillus niger and Endomyces fibuliger contaminating bakery products.

    PubMed

    Valerio, Francesca; Favilla, Mara; De Bellis, Palmira; Sisto, Angelo; de Candia, Silvia; Lavermicocca, Paola

    2009-09-01

    Thirty samples of Italian durum wheat semolina and whole durum wheat semolina, generally used for the production of Southern Italy's traditional breads, were subjected to microbiological analysis in order to explore their lactic acid bacteria (LAB) diversity and to find strains with antifungal activity. A total of 125 presumptive LAB isolates (Gram-positive and catalase-negative) were characterized by repetitive extragenic palindromic-PCR (REP-PCR) and sequence analysis of the 16S rRNA gene, leading to the identification of the following species: Weissella confusa, Weissella cibaria, Leuconostoc citreum, Leuconostoc mesenteroides, Lactococcus lactis, Lactobacillus rossiae and Lactobacillus plantarum. The REP-PCR results delineated 17 different patterns whose cluster analysis clearly differentiated W. cibaria from W. confusa isolates. Seventeen strains, each characterized by a different REP-PCR pattern, were screened for their antifungal properties. They were grown in a flour-based medium, comparable to a real food system, and the resulting fermentation products (FPs) were tested against fungal species generally contaminating bakery products, Aspergillus niger, Penicillium roqueforti and Endomyces fibuliger. The results of the study indicated a strong inhibitory activity - comparable to that obtained with the common preservative calcium propionate (0.3% w/v) - of ten LAB strains against the most widespread contaminant of bakery products, P. roqueforti. The screening also highlighted the unexplored antifungal activity of L. citreum, L. rossiae and W. cibaria (1 strain), which inhibited all fungal strains to the same or a higher extent compared with calcium propionate. The fermentation products of these three strains were characterized by low pH values, and a high content of lactic and acetic acids.

  5. Short-Chain Fatty Acids Enhance the Lipid Accumulation of 3T3-L1 Cells by Modulating the Expression of Enzymes of Fatty Acid Metabolism.

    PubMed

    Yu, Haining; Li, Ran; Huang, Haiyong; Yao, Ru; Shen, Shengrong

    2018-01-01

    Short-chain fatty acids (SCFA) such as acetic acid, propionic acid, and butyric acid are produced by fermentation by gut microbiota. In this paper, we investigate the effects of SCFA on 3T3-L1 cells and the underlying molecular mechanisms. The cells were treated with acetic acid, propionic acid, or butyric acid when cells were induced to differentiate into adipocytes. MTT assay was employed to detect the viability of 3T3-L1 cells. Oil Red O staining was used to visualize the lipid content in 3T3-L1 cells. A triglyceride assay kit was used to detect the triacylglycerol content in 3T3-L1 cells. qRT-PCR and Western blot were used to evaluate the expression of metabolic enzymes. MTT results showed that safe concentrations of acetic acid, propionic acid, and butyric acid were less than 6.4, 3.2, and 0.8 mM, respectively. Oil Red O staining and triacylglycerols detection results showed that treatment with acetic acid, propionic acid, and butyric acid accelerated the 3T3-L1 adipocyte differentiation. qRT-PCR and Western blot results showed that the expressions of lipoprotein lipase (LPL), adipocyte fatty acid binding protein 4 (FABP4), fatty acid transporter protein 4 (FATP4), and fatty acid synthase (FAS) were significantly increased by acetic acid, propionic acid, and butyric acid treatment during adipose differentiation (p < 0.05). In conclusion, SCFA promoted lipid accumulation by modulating the expression of enzymes of fatty acid metabolism. © 2018 AOCS.

  6. 9 CFR 424.23 - Prohibited uses.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (propyl p-hydroxybenzoate), calcium propionate, sodium propionate, benzoic acid, and sodium benzoate may... sorbate, sodium sorbate, and other salts of sorbic acid shall not be used in cooked sausages or any other...

  7. 9 CFR 424.23 - Prohibited uses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (propyl p-hydroxybenzoate), calcium propionate, sodium propionate, benzoic acid, and sodium benzoate may... sorbate, sodium sorbate, and other salts of sorbic acid shall not be used in cooked sausages or any other...

  8. 9 CFR 424.23 - Prohibited uses.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (propyl p-hydroxybenzoate), calcium propionate, sodium propionate, benzoic acid, and sodium benzoate may... sorbate, sodium sorbate, and other salts of sorbic acid shall not be used in cooked sausages or any other...

  9. 9 CFR 424.23 - Prohibited uses.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (propyl p-hydroxybenzoate), calcium propionate, sodium propionate, benzoic acid, and sodium benzoate may... sorbate, sodium sorbate, and other salts of sorbic acid shall not be used in cooked sausages or any other...

  10. Ground transport stress affects bacteria in the rumen of beef cattle: A real-time PCR analysis.

    PubMed

    Deng, Lixin; He, Cong; Zhou, Yanwei; Xu, Lifan; Xiong, Huijun

    2017-05-01

    Transport stress syndrome often appears in beef cattle during ground transportation, leading to changes in their capacity to digest food due to changes in rumen microbiota. The present study aimed to analyze bacteria before and after cattle transport. Eight Xianan beef cattle were transported over 1000 km. Rumen fluid and blood were sampled before and after transport. Real-time PCR was used to quantify rumen bacteria. Cortisol and adrenocorticotrophic hormone (ACTH) were measured. Cortisol and ACTH were increased on day 1 after transportation and decreased by day 3. Cellulolytic bacteria (Fibrobacter succinogenes and Ruminococcus flavefaciens), Ruminococcus amylophilus and Prevotella albensis were increased at 6 h and declined by 15 days after transport. There was a significant reduction in Succinivibrio dextrinosolvens, Prevotella bryantii, Prevotella ruminicola and Anaerovibrio lipolytica after transport. Rumen concentration of acetic acid increased after transport, while rumen pH and concentrations of propionic and butyric acids were decreased. Body weight decreased by 3 days and increased by 15 days after transportation. Using real-time PCR analysis, we detected changes in bacteria in the rumen of beef cattle after transport, which might affect the growth of cattle after transport. © 2016 Japanese Society of Animal Science.

  11. Evaluation of the addition of organic acids in the feed and/or water for broilers and the subsequent recovery of salmonella typhimurium from litter and ceca

    USDA-ARS?s Scientific Manuscript database

    Broiler Salmonella challenge experiments were conducted evaluating efficacy of formic and propionic acid feed supplements to suppress environmental and cecal Salmonella prevalence. In experiment 1, treatments were: formic acid, propionic acid, or basal control with no added acids. Seeder chicks we...

  12. Propionic and butyric acids, formed in the caecum of rats fed highly fermentable dietary fibre, are reflected in portal and aortic serum.

    PubMed

    Jakobsdottir, Greta; Jädert, Cecilia; Holm, Lena; Nyman, Margareta E

    2013-11-14

    SCFA are important end products formed during colonic fermentation of dietary fibre (DF). It has been suggested that propionic and butyric acids affect metabolic parameters, low-grade systemic inflammation, insulin resistance and obesity. The aim of the present study was to investigate whether the various SCFA profiles observed after fermentation in the caecum of rats fed pectin, guar gum and fructo-oligosaccharides (FOS) were also represented in hepatic portal and aortic serum. The SCFA in serum were extracted using hollow fibre-supported liquid membrane extraction before GLC analysis. The concentrations of acetic, propionic and butyric acids in caecal content correlated well with those in portal serum (P< 0·001) for all the three diets. A weaker correlation was found for propionic and butyric acids between the caecal content and aortic serum (P< 0·05). Butyric acid concentration in caecal content was also reflected in the aortic serum (P= 0·019) of rats fed FOS. FOS gave rather low amounts of the SCFA, especially butyric acid, but caecal tissue weight was higher with FOS than with the other two diets. This may be explained by rapid fermentation and quick utilisation/absorption of the SCFA. The present study also showed that propionic acid was metabolised/utilised to a higher extent than butyric acid by colonocytes before reaching the liver. We conclude that the formation of propionic and butyric acids in the caecum is reflected by increased concentrations in the aortic blood. This approach may therefore simplify the evaluation and study of SCFA from DF in human subjects.

  13. Extractive fermentation for enhanced propionic acid production from lactose by Propionibacterium acidipropionici

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

    Jin, Z.; Yang, S.T.

    1998-05-01

    An extractive fermentation process using an amine extractant and a hollow-fiber membrane extractor to selectively remove propionic acid from the fermentation broth was developed to produce propionate from lactose. Compared to the conventional batch fermentation, the extractive fermentation had a much higher productivity ({approximately}1 g/(L{center_dot}h) or 5-fold increase), higher propionate yield (up to 0.66 g/g or more than 20% increase), higher final product concentration (75 g/L or higher), and higher product purity ({approximately}90%). Meanwhile, acetate and succinate productions in the extractive fermentation were significantly reduced. The improved fermentation performance can be attributed to the reduced product inhibition and a possiblemore » metabolic pathway shift to favor more propionic but less acetic and succinic acid production. The process was stable and gave consistent long-term performance over the 1.5-month period studied. The effects of propionate concentration, pH, and amine content in the solvent on the extractive fermentation were also studied and are discussed in this paper.« less

  14. Quantitative analyses of the bacterial microbiota of rearing environment, tilapia and common carp cultured in earthen ponds and inhibitory activity of its lactic acid bacteria on fish spoilage and pathogenic bacteria.

    PubMed

    Kaktcham, Pierre Marie; Temgoua, Jules-Bocamdé; Ngoufack Zambou, François; Diaz-Ruiz, Gloria; Wacher, Carmen; Pérez-Chabela, María de Lourdes

    2017-02-01

    The present study aimed to evaluate the bacterial load of water, Nile Tilapia and common Carp intestines from earthen ponds, isolate lactic acid bacteria (LAB) and assess their antimicrobial activity against fish spoilage and pathogenic bacteria. Following enumeration and isolation of microorganisms the antimicrobial activity of the LAB isolates was evaluated. Taxonomic identification of selected antagonistic LAB strains was assessed, followed by partial characterisation of their antimicrobial metabolites. Results showed that high counts (>4 log c.f.u ml -1 or 8 log c.f.u g -1 ) of total aerobic bacteria were recorded in pond waters and fish intestines. The microbiota were also found to be dominated by Salmonella spp., Vibrio spp., Staphylococcus spp. and Escherichia coli. LAB isolates (5.60%) exhibited potent direct and extracellular antimicrobial activity against the host-derived and non host-derived spoilage and pathogenic bacteria. These antagonistic isolates were identified and Lactococcus lactis subsp. lactis was found as the predominant (42.85%) specie. The strains displayed the ability to produce lactic, acetic, butyric, propionic and valeric acids. Bacteriocin-like inhibitory substances with activity against Gram-positive and Gram-negative (Vibrio spp. and Pseudomonas aeruginosa) bacteria were produced by three L. lactis subsp. lactis strains. In this study, the LAB from the microbiota of fish and pond water showed potent antimicrobial activity against fish spoilage or pathogenic bacteria from the same host or ecological niche. The studied Cameroonian aquatic niche is an ideal source of antagonistic LAB that could be appropriate as new fish biopreservatives or disease control agents in aquaculture under tropical conditions in particular or worldwide in general.

  15. Improved production of propionic acid driven by hydrolyzed liquid containing high concentration of l-lactic acid from co-fermentation of food waste and sludge.

    PubMed

    Li, Xiang; Zhang, Wenjuan; Ma, Li; Lai, Sizhou; Zhao, Shu; Chen, Yinguang; Liu, Yanan

    2016-11-01

    This study investigated the feasibility of improved production propionic acid-enriched volatile fatty acid (VFA) from high concentration (Cs) of food waste and waste activated sludge (WAS) via lactic acid pathway by using of Propionibacterium acidipropionici. It was observed that production of l-lactate overwhelmed to d-lactate at first stage, which improved from 3.21 to 35.45gCOD/L with increase of substrate Cs. However, kinetic model analysis indicated that P. acidipropionici growth rate μmax was decreased with increase of l-lactate concentration, which explained second stage free cell fermentation of propionic acid was inhibited when fed by first stage liquid from R-40, R-55 and R-70. Then, the fibrous bed bioreactor was employed to eliminate the feed inhibition. The maximal percentage of propionic acid (68.3%) and production (16.31gCOD/L) was obtained by feeding liquid of R-55, which was improved by 3.33 folds compared to the free cell fermentation. Copyright © 2016. Published by Elsevier Ltd.

  16. Compartmentalization of amino acids in surfactant aggregates - Partitioning between water and aqueous micellar sodium dodecanoate and between hexane and dodecylammonium propionate trapped water in hexane

    NASA Technical Reports Server (NTRS)

    Fendler, J. H.; Nome, F.; Nagyvary, J.

    1975-01-01

    The partitioning of amino acids (glycine, alanine, leucine, phenylalanine, histidine, aspartic acid, glutamic acid, lysine, isoleucine, threonine, serine, valine, proline, arginine) in aqueous and nonaqueous micellar systems was studied experimentally. Partitioning from neat hexane into dodecylammonium propionate trapped water in hexane was found to be dependent on both electrostatic and hydrophobic interactions, which implies that the interior of dodecylammonium propionate aggregates is negatively charged and is capable of hydrogen bonding in addition to providing a hydrophobic environment. Unitary free energies of transfer of amino acid side chains from hexane to water were determined and solubilities of amino acids in neat hexane substantiated the amino acid hydrophobicity scale. The relevance of the experiments to prebiotic chemistry was examined.

  17. Identification and quantification of antifungal compounds produced by lactic acid bacteria and propionibacteria.

    PubMed

    Le Lay, Céline; Coton, Emmanuel; Le Blay, Gwenaëlle; Chobert, Jean-Marc; Haertlé, Thomas; Choiset, Yvan; Van Long, Nicolas Nguyen; Meslet-Cladière, Laurence; Mounier, Jérôme

    2016-12-19

    Fungal growth in bakery products represents the most frequent cause of spoilage and leads to economic losses for industrials and consumers. Bacteria, such as lactic acid bacteria and propionibacteria, are commonly known to play an active role in preservation of fermented food, producing a large range of antifungal metabolites. In a previous study (Le Lay et al., 2016), an extensive screening performed both in vitro and in situ allowed for the selection of bacteria exhibiting an antifungal activity. In the present study, active supernatants against Penicillium corylophilum and Aspergillus niger were analyzed to identify and quantify the antifungal compounds associated with the observed activity. Supernatant treatments (pH neutralization, heating and addition of proteinase K) suggested that organic acids played the most important role in the antifungal activity of each tested supernatant. Different methods (HPLC, mass spectrometry, colorimetric and enzymatic assays) were then applied to analyze the supernatants and it was shown that the main antifungal compounds corresponded to lactic, acetic and propionic acids, ethanol and hydrogen peroxide, as well as other compounds present at low levels such as phenyllactic, hydroxyphenyllactic, azelaic and caproic acids. Based on these results, various combinations of the identified compounds were used to evaluate their effect on conidial germination and fungal growth of P. corylophilum and Eurotium repens. Some combinations presented the same activity than the bacterial culture supernatant thus confirming the involvement of the identified molecules in the antifungal activity. The obtained results suggested that acetic acid was mainly responsible for the antifungal activity against P. corylophilum and played an important role in E. repens inhibition. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Design and application of a synthetic DNA standard for real-time PCR analysis of microbial communities in a biogas digester.

    PubMed

    May, T; Koch-Singenstreu, M; Ebling, J; Stantscheff, R; Müller, L; Jacobi, F; Polag, D; Keppler, F; König, H

    2015-08-01

    A synthetic DNA fragment containing primer binding sites for the quantification of ten different microbial groups was constructed and evaluated as a reliable enumeration standard for quantitative real-time PCR (qPCR) analyses. This approach has been exemplary verified for the quantification of several methanogenic orders and families in a series of samples drawn from a mesophilic biogas plant. Furthermore, the total amounts of bacteria as well as the number of sulfate-reducing and propionic acid bacteria as potential methanogenic interaction partners were successfully determined. The obtained results indicated a highly dynamic microbial community structure which was distinctly affected by the organic loading rate, the substrate selection, and the amount of free volatile fatty acids in the fermenter. Methanosarcinales was the most predominant methanogenic order during the 3 months of observation despite fluctuating process conditions. During all trials, the modified quantification standard indicated a maximum of reproducibility and efficiency, enabling this method to open up a wide range of novel application options.

  19. The structure of an acylated inositol mannoside in the lipids of propionic acid bacteria

    PubMed Central

    Shaw, N.; Dinglinger, F.

    1969-01-01

    1. Lipids were extracted from five strains of Propionibacterium with chloroform–methanol mixtures and fractionated by chromatography on silicic acid. 2. All five extracts contained a glycolipid composed of fatty acids, inositol and mannose in the molar proportions 2:1:1. 3. Hydrolysis of the glycolipid with alkali gave a mixture of fatty acids and O-α-d-mannopyranosyl-(1→2)-myoinositol. 4. Analysis of the fatty acids by g.l.c. showed that they were predominantly straight- and branched-chain isomers of pentadecanoic acid and heptadecanoic acid. 5. The location and distribution of the fatty acid residues in the molecule was established by periodate oxidation studies and mass spectrometry. The structure of the major glycolipid is 1-O-pentadecanoyl-2-O-(6-O-heptadecanoyl-α-d-mannopyranosyl)myoinositol. 6. The glycolipids are located in the membrane; the cell walls are devoid of lipid. 7. Possible functions of the glycolipid are discussed. PMID:5821733

  20. Impact of dietary fiber fermentation from cereal grains on metabolite production by the fecal microbiota from normal weight and obese individuals.

    PubMed

    Yang, Junyi; Keshavarzian, Ali; Rose, Devin J

    2013-09-01

    Gut bacteria may influence obesity through the metabolites produced by dietary fiber fermentation (mainly, short-chain fatty acids [SCFA]). Five cereal grain samples (wheat, rye, maize [corn], rice, and oats) were subjected to in vitro digestion and fermentation using fecal samples from 10 obese and nine normal weight people. No significant differences in total SCFA production between the normal weight and obese groups were observed [279 (12) vs. 280 (12), mean (standard error), respectively; P=.935]. However, the obese microbiota resulted in elevated propionate production compared with that of normal weight [24.8(2.2) vs. 17.8(1.9), respectively; P=.008]. Rye appeared to be particularly beneficial among grain samples due to the lowest propionate production and highest butyrate production during fermentation. These data suggest that the dietary fibers from cereal grains affect bacterial metabolism differently in obese and normal weight classes and that certain grains may be particularly beneficial for promoting gut health in obese states.

  1. Effects of a propionic-acid based preservative on storage characteristics of alfalfa-orchardgrass hay in large-rectangular bales

    USDA-ARS?s Scientific Manuscript database

    For many years, various formulations of organic acids have been marketed as preservatives, most specifically for use on hays that could not be field-dried to moisture concentrations low enough to reduce or eliminate spontaneous heating during storage. These preservatives are often propionic-acid-bas...

  2. Antimicrobial and immune modulatory effects of lactic acid and short chain fatty acids produced by vaginal microbiota associated with eubiosis and bacterial vaginosis

    PubMed Central

    Aldunate, Muriel; Srbinovski, Daniela; Hearps, Anna C.; Latham, Catherine F.; Ramsland, Paul A.; Gugasyan, Raffi; Cone, Richard A.; Tachedjian, Gilda

    2015-01-01

    Lactic acid and short chain fatty acids (SCFAs) produced by vaginal microbiota have reported antimicrobial and immune modulatory activities indicating their potential as biomarkers of disease and/or disease susceptibility. In asymptomatic women of reproductive-age the vaginal microbiota is comprised of lactic acid-producing bacteria that are primarily responsible for the production of lactic acid present at ~110 mM and acidifying the vaginal milieu to pH ~3.5. In contrast, bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is characterized by decreased lactic acid-producing microbiota and increased diverse anaerobic bacteria accompanied by an elevated pH>4.5. BV is also characterized by a dramatic loss of lactic acid and greater concentrations of mixed SCFAs including acetate, propionate, butyrate, and succinate. Notably women with lactic acid-producing microbiota have more favorable reproductive and sexual health outcomes compared to women with BV. Regarding the latter, BV is associated with increased susceptibility to sexually transmitted infections (STIs) including HIV. In vitro studies demonstrate that lactic acid produced by vaginal microbiota has microbicidal and virucidal activities that may protect against STIs and endogenous opportunistic bacteria as well as immune modulatory properties that require further characterization with regard to their effects on the vaginal mucosa. In contrast, BV-associated SCFAs have far less antimicrobial activity with the potential to contribute to a pro-inflammatory vaginal environment. Here we review the composition of lactic acid and SCFAs in respective states of eubiosis (non-BV) or dysbiosis (BV), their effects on susceptibility to bacterial/viral STIs and whether they have inherent microbicidal/virucidal and immune modulatory properties. We also explore their potential as biomarkers for the presence and/or increased susceptibility to STIs. PMID:26082720

  3. Purification and characterization of a novel α-D-glucosidase from Lactobacillus fermentum with unique substrate specificity towards resistant starch.

    PubMed

    Addala, Mousami Shankar; Gudipati, Muralikrishna

    2018-01-15

    Resistant starch is not digestible in the small intestine and is fermented by lactic acid bacteria in the large intestine into short chain fatty acids, such as acetate, propionate and butyrate, which result in several health benefits in analogy with dietary fibre components. The mode and mechanism of resistant starch degradation by lactic acid bacteria is still not understood. In the present study, we have purified α-D-glucosidase from Lactobacillus fermentum NCDC 156 by employing three sequential steps i.e. ultra filtration, DEAE-cellulose and Sephadex G-100 chromatographies. It was found to be a monomeric protein (~50 kDa). The optimum pH and temperature of this enzyme were found to be 5.5 and 37°C, respectively. Under optimised conditions with p-nitrophenyl-D-glucopyranoside as the substrate, the enzyme exhibited a K m of 0.97 mM. Its activity was inhibited by Hg 2+ and oxalic acid. N-terminal blocked purified enzyme was subjected to lysyl endopeptidase digestion and the resultant peptides were subjected to BLAST analysis to understand their homology with other α-D-glucosidases from lactobacillus species.

  4. Fate of Escherichia coli O157:H7 and bacterial diversity in corn silage contaminated with the pathogen and treated with chemical or microbial additives.

    PubMed

    Ogunade, I M; Jiang, Y; Kim, D H; Cervantes, A A Pech; Arriola, K G; Vyas, D; Weinberg, Z G; Jeong, K C; Adesogan, A T

    2017-03-01

    Inhibiting the growth of Escherichia coli O157:H7 (EC) in feeds may prevent the transmission or cycling of the pathogen on farms. The first objective of this study was to examine if addition of propionic acid or microbial inoculants would inhibit the growth of EC during ensiling, at silo opening, or after aerobic exposure. The second objective was to examine how additives affected the bacterial community composition in corn silage. Corn forage was harvested at approximately 35% dry matter, chopped to a theoretical length of cut of 10 mm, and ensiled after treatment with one of the following: (1) distilled water (control); (2) 1 × 10 5 cfu/g of EC (ECCH); (3) EC and 1 × 10 6 cfu/g of Lactobacillus plantarum (ECLP); (4) EC and 1 × 10 6 cfu/g of Lactobacillus buchneri (ECLB); and (5) EC and 2.2 g/kg (fresh weight basis) of propionic acid, containing 99.5% of the acid (ECA). Each treatment was ensiled in quadruplicate in laboratory silos for 0, 3, 7, and 120 d and analyzed for EC, pH, and organic acids. Samples from d 0 and 120 were also analyzed for chemical composition. Furthermore, samples from d 120 were analyzed for ammonia N, yeasts and molds, lactic acid bacteria, bacterial community composition, and aerobic stability. The pH of silages from all treatments decreased below 4 within 3 d of ensiling. Escherichia coli O157:H7 counts were below the detection limit in all silages after 7 d of ensiling. Treatment with L. buchneri and propionic acid resulted in fewer yeasts and greater aerobic stability compared with control, ECCH, and ECLP silages. Compared with the control, the diversity analysis revealed a less diverse bacterial community in the ECLP silage and greater abundance of Lactobacillus in the ECLP and ECA silages. The ECLB silage also contained greater abundance of Acinetobacter and Weissella than other silages. Subsamples of silages were reinoculated with 5 × 10 5 cfu/g of EC either immediately after silo opening or after 168 h of aerobic exposure, and EC were enumerated after 6 or 24 h, respectively. All silages reinoculated with EC immediately after silo opening (120 h) had similar low pH values (<4.0) and EC counts were below the detection limit. The ECCH and ECLP silages reinoculated with EC after 168 h of aerobic exposure had relatively high pH values (>5.0) and EC counts (5.39 and 5.30 log cfu/g, respectively) 24 h later. However, those treated with L. buchneri or propionic acid had lower pH values (4.24 or 3.96, respectively) and lower EC counts (1.32 log cfu/g or none, respectively). During ensiling, EC was eliminated from all silages at pH below 4.0. During aerobic exposure, the growth of EC was reduced or prevented in silages that had been treated with L. buchneri or propionic acid at ensiling, respectively. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Dose and time response of ruminally infused algae on rumen fermentation characteristics, biohydrogenation and Butyrivibrio group bacteria in goats.

    PubMed

    Zhu, Honglong; Fievez, Veerle; Mao, Shengyong; He, Wenbo; Zhu, Weiyun

    2016-01-01

    Micro-algae could inhibit the complete rumen BH of dietary 18-carbon unsaturated fatty acid (UFAs). This study aimed to examine dose and time responses of algae supplementation on rumen fermentation, biohydrogenation and Butyrivibrio group bacteria in goats. Six goats were used in a repeated 3 × 3 Latin square design, and offered a fixed diet. Algae were infused through rumen cannule with 0 (Control), 6.1 (L-Alg), or 18.3 g (H-Alg) per day. Rumen contents were sampled on d 0, 3, 7, 14 and 20. H-Alg reduced total volatile fatty acid concentration and acetate molar proportion (P < 0.05), and increased propionate molar proportion (P < 0.05), whereas L-Alg had no effect on rumen fermentation. Changes in proportions of acetate and propionate in H-Alg were obvious from d 7 onwards and reached the largest differences with the control on d 14. Algae induced a dose-dependent decrease in 18:0 and increased trans-18:1 in the ruminal content (P < 0.05). H-Alg increased the concentrations of t9, t11-18:2 and t11, c15-18:2 (P < 0.05). L-Alg only seemed to induce a transient change in 18-carbon isomers, while H-Alg induced a rapid elevation, already obvious on d 3, concentrations of these fatty acid rose in some cases again on d 20. Algae had no effect on the abundances of Butyrivibrio spp. and Butyrivibrio proteoclasticus (P > 0.10), while H-Alg reduced the total bacteria abundance (P < 0.05). However, this was induced by a significant difference between control and H-Alg on d 14 (-4.43 %). Afterwards, both treatments did not differ as increased variation in the H-Alg repetitions, with in some cases a return of the bacterial abundance to the basal level (d 0). Changes in rumen fermentation and 18-carbon UFAs metabolism in response to algae were related to the supplementation level, but there was no evidence of shift in ruminal biohydrogenation pathways towards t10-18:1. L-Alg mainly induced a transient effect on rumen biohydrogenation of 18-carbon UFAs, while H-Alg showed an acute inhibition and these effects were not associated with the known hydrogenating bacteria.

  6. Acidity and complex formation studies of 3-(adenine-9-yl)-propionic and 3-(thymine-1-yl)-propionic acids in ethanol-water media

    NASA Astrophysics Data System (ADS)

    Hammud, Hassan H.; El Shazly, Shawky; Sonji, Ghassan; Sonji, Nada; Bouhadir, Kamal H.

    2015-05-01

    The ligands 3-(adenine-9-yl)propionic acid (AA) and 3-(thymine-1-yl)propionic acid (TA) were prepared by N9-alkylation of adenine and N1-alkylation of thymine with ethylacrylate in presence of a base catalyst, followed by acid hydrolysis of the formed ethyl esters to give the corresponding propionic acid derivatives. The products were characterized by spectral methods (FTIR, 1H NMR and 13C NMR), which confirm their structures. The dissociation constants of ligands, were potentiometrically determined in 0.3 M KCl at 20-50 °C temperature range. The work was extended to study complexation behavior of AA and TA with various biologically important divalent metal ions (Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Mn2+ and Pb2+) in 50% v/v water-ethanol medium at four different temperatures, keeping ionic strength constant (0.3 M KCl). The order of the stability constants of the formed complexes decreases in the sequence Cu2+ > Pb2+ > Zn2+ > Ni2+ > Co2+ > Mn2+ > Cd2+ for both ligands. The effect of temperature was also studied and the corresponding thermodynamic functions (ΔG, ΔH, ΔS) were derived and discussed. The formation of metal complexes has been found to be spontaneous, and the stability constants were dependant markedly on the basicity of the ligands.

  7. Effects of targeted delivery of propionate to the human colon on appetite regulation, body weight maintenance and adiposity in overweight adults

    PubMed Central

    Chambers, Edward S; Viardot, Alexander; Psichas, Arianna; Morrison, Douglas J; Murphy, Kevin G; Zac-Varghese, Sagen E K; MacDougall, Kenneth; Preston, Tom; Tedford, Catriona; Finlayson, Graham S; Blundell, John E; Bell, Jimmy D; Thomas, E Louise; Mt-Isa, Shahrul; Ashby, Deborah; Gibson, Glen R; Kolida, Sofia; Dhillo, Waljit S; Bloom, Stephen R; Morley, Wayne; Clegg, Stuart; Frost, Gary

    2015-01-01

    Objective The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults. Design To investigate whether propionate promotes PYY and GLP-1 secretion, a primary cultured human colonic cell model was developed. To deliver propionate specifically to the colon, we developed a novel inulin-propionate ester. An acute randomised, controlled cross-over study was used to assess the effects of this inulin-propionate ester on energy intake and plasma PYY and GLP-1 concentrations. The long-term effects of inulin-propionate ester on weight gain were subsequently assessed in a randomised, controlled 24-week study involving 60 overweight adults. Results Propionate significantly stimulated the release of PYY and GLP-1 from human colonic cells. Acute ingestion of 10 g inulin-propionate ester significantly increased postprandial plasma PYY and GLP-1 and reduced energy intake. Over 24 weeks, 10 g/day inulin-propionate ester supplementation significantly reduced weight gain, intra-abdominal adipose tissue distribution, intrahepatocellular lipid content and prevented the deterioration in insulin sensitivity observed in the inulin-control group. Conclusions These data demonstrate for the first time that increasing colonic propionate prevents weight gain in overweight adult humans. Trial registration number NCT00750438. PMID:25500202

  8. The effect of propionic acid and valeric acid on the cell cycle in root meristems of Pisum sativum

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

    Tramontano, W.A.; Yang, Shauyu; Delillo, A.R.

    1990-01-01

    Propionic acid and valeric acid at 1mM reduced the mitotic index of root meristem cells of Pisum sativum to < 1% after 12 hr in aerated White's medium. This effect varied with different acid concentrations. After a 12 hr exposure to either acid, seedlings transferred to fresh medium without either acid, resumed their normal mitotic index after 12 hr, with a burst of mitosis 8 hr post-transfer. Exposure of root meristem cells to either acid also inhibited ({sup 3}H)-TdR incorporation. Neither acid significantly altered the distribution of meristematic cells in G1 and G2 after 12 hr. The incorporation of ({supmore » 3}H) - uridine was also unaltered by the addition of either acid. This information suggests that propionic acid and valeric acid, limit progression through the cell cycle by inhibiting DNA synthesis and arresting cells in G1 and G2. These results were consistent with previous data which utilized butyric acid.« less

  9. The diet-derived short chain fatty acid propionate improves beta-cell function in humans and stimulates insulin secretion from human islets in vitro.

    PubMed

    Pingitore, Attilio; Chambers, Edward S; Hill, Thomas; Maldonado, Inmaculada Ruz; Liu, Bo; Bewick, Gavin; Morrison, Douglas J; Preston, Tom; Wallis, Gareth A; Tedford, Catriona; Castañera González, Ramón; Huang, Guo C; Choudhary, Pratik; Frost, Gary; Persaud, Shanta J

    2017-02-01

    Diet-derived short chain fatty acids (SCFAs) improve glucose homeostasis in vivo, but the role of individual SCFAs and their mechanisms of action have not been defined. This study evaluated the effects of increasing colonic delivery of the SCFA propionate on β-cell function in humans and the direct effects of propionate on isolated human islets in vitro. For 24 weeks human subjects ingested an inulin-propionate ester that delivers propionate to the colon. Acute insulin, GLP-1 and non-esterified fatty acid (NEFA) levels were quantified pre- and post-supplementation in response to a mixed meal test. Expression of the SCFA receptor FFAR2 in human islets was determined by western blotting and immunohistochemistry. Dynamic insulin secretion from perifused human islets was quantified by radioimmunoassay and islet apoptosis was determined by quantification of caspase 3/7 activities. Colonic propionate delivery in vivo was associated with improved β-cell function with increased insulin secretion that was independent of changes in GLP-1 levels. Human islet β-cells expressed FFAR2 and propionate potentiated dynamic glucose-stimulated insulin secretion in vitro, an effect that was dependent on signalling via protein kinase C. Propionate also protected human islets from apoptosis induced by the NEFA sodium palmitate and inflammatory cytokines. Our results indicate that propionate has beneficial effects on β-cell function in vivo, and in vitro analyses demonstrated that it has direct effects to potentiate glucose-stimulated insulin release and maintain β-cell mass through inhibition of apoptosis. These observations support ingestion of propiogenic dietary fibres to maintain healthy glucose homeostasis. © 2016 John Wiley & Sons Ltd.

  10. Metagenomics detects functional shifts in the bovine rumen microbiota in response to propionate intake

    USDA-ARS?s Scientific Manuscript database

    Optimizing rumen microbial ecosystem output is essential towards improved ruminant agriculture. Ruminal infusion or intake of propionate, one of the predominant volatile fatty acids, has important implications for host physiology. However, how the rumen microbiota responds to propionate administrat...

  11. Role of glutamine in cobinamide biosynthesis in Propionibacterium shermanii

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

    Eliseev, A.A.; Pushkin, A.V.; Belozerova, E.V.

    1987-01-10

    The role of glutamine as a possible donor of amide groups in the biosynthesis of vitamin B/sub 12/ was investigated. In the incubation of P. shermanii cells preliminarily exhausted with respect to nitrogen on media containing ammonium sulfate or asparagine, the glutamine synthetase inhibitor methionine sulfoximine suppressed the formation of cobinamide (factor B) from the monoamide of cobiric acid (by 75 and 59%, respectively). At the same time, the inhibitor did not affect cobinamide synthesis on a medium with glutamine. The amide group of glutamine, labeled with /sup 13/N, was used for the amidation of corrinoids four times as efficientlymore » as the amine group. It was concluded that a glutamine-dependent synthetase, which catalyzes the amidation of cobiric acids with the formation of cobinamide, functions in cells of propionic acid bacteria.« less

  12. 2-(2-Methyl-4-chlorophenoxy)propionic acid (MCPP)

    Integrated Risk Information System (IRIS)

    2 - ( 2 - Methyl - 4 - chlorophenoxy ) propionic acid ( MCPP ) ; CASRN 93 - 65 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( H

  13. Evaluation of the addition of organic acids in the feed and/or water for broilers and the subsequent recovery of Salmonella Typhimurium from litter and ceca.

    PubMed

    Bourassa, D V; Wilson, K M; Ritz, C R; Kiepper, B K; Buhr, R J

    2018-01-01

    Three separate broiler Salmonella Typhimurium challenge experiments were conducted evaluating efficacy of formic and propionic acid feed supplements to suppress environmental and cecal Salmonella Typhimurium prevalence. In experiment 1, broilers were provided feed with 1 kg/ton formic acid or 5 kg/ton propionic acid feed additives or a basal control diet. At the day of placement, half of the pens were inoculated with seeder chicks orally challenged with a marker strain of Salmonella Typhimurium and to yield challenged and adjacent nonchallenged pens. No differences in weekly litter samples or cecal Salmonella prevalence at 3 or 6 wk among feeding treatments were detected. In experiment 2, treatments were: 2 kg/ton propionic acid in feed, 1.0 mL/L formic acid in water, both propionic acid in feed and formic acid in water, and a basal control. Every pen was challenged with seeder chicks inoculated with Salmonella Typhimurium. By 6 wk all pens maintained detectable litter Salmonella, and broilers provided both propionic acid in feed and formic acid in water had the lowest cecal recovery (35%), compared to the control (60%). In experiment 3, treatments were: formic acid at 4 or 6 kg/ton from wk 0 to 6 or for only the last wk, propionic acid at 5 or 10 kg/ton for only the last wk, and a basal control. Each pen was challenged with Salmonella Typhimurium inoculated seeder chicks. By 6 wk, broilers fed formic acid (4 kg/ton) for the entire growout had no Salmonella-positive ceca (0/30). All treatments that provided acid supplemented feed for only the last wk had 3-13% Salmonella-positive ceca. These experiments indicate that adding formic acid to broiler feed appears to prevent Salmonella colonization from challenge pens entering into the adjacent nonchallenge pens. Feeding formic acid (4 kg/ton) for 6 wk resulted in no recovery of Salmonella from ceca compared to the control prevalence of 17%. Published by Oxford University Press on behalf of Poultry Science Association 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  14. Patterns of Gram-stained fecal flora as a quick diagnostic marker in patients with severe SIRS.

    PubMed

    Shimizu, Kentaro; Ogura, Hiroshi; Tomono, Kazunori; Tasaki, Osamu; Asahara, Takashi; Nomoto, Koji; Morotomi, Masami; Matsushima, Asako; Nakahori, Yasutaka; Yamano, Shuhei; Osuka, Akinori; Kuwagata, Yasuyuki; Sugimoto, Hisashi

    2011-06-01

    The gut is an important target organ of injury during critically ill conditions. Although Gram staining is a common and quick method for identifying bacteria, its clinical application has not been fully evaluated in critically ill conditions. This study's aims were to identify patterns of Gram-stained fecal flora and compare them to cultured bacterial counts and to investigate the association between the patterns and septic complications in patients with severe systemic inflammatory response syndrome (SIRS). Fifty-two patients with SIRS were included whose Gram-stained fecal flora was classified into three patterns. In a diverse pattern, large numbers of multiple kinds of bacteria completely covered the field. In a single pattern, one specific kind of bacteria or fungi predominantly covered the field. In a depleted pattern, most bacteria were diminished in the field. In the analysis of fecal flora, the numbers of total obligate anaerobes in the depleted pattern was significantly lower than those in the diverse pattern and single pattern (p < 0.05). The concentrations of total organic acids, acetic acid, and propionic acid in the depleted pattern were significantly lower than those in diverse pattern and single pattern (p < 0.05). Mortality due to multiple organ dysfunction syndrome for the single pattern (52%) and the depleted pattern (64%) was significantly higher than that for the diverse pattern (6%) (p < 0.05). Gram-stained fecal flora can be classified into three patterns and are associated with both cultured bacterial counts and clinical information. Gram-stained fecal bacteria can be used as a quick bedside diagnostic marker for severe SIRS patients.

  15. Passiflora edulis peel intake and ulcerative colitis: approaches for prevention and treatment.

    PubMed

    Cazarin, Cinthia Bb; da Silva, Juliana K; Colomeu, Talita C; Batista, Angela G; Vilella, Conceição A; Ferreira, Anderson L; Junior, Stanislau Bogusz; Fukuda, Karina; Augusto, Fabio; de Meirelles, Luciana R; Zollner, Ricardo de L; Junior, Mário R Maróstica

    2014-05-01

    Inflammatory bowel disease is a chronic relapsing disease that affects millions of people worldwide; its pathogenesis is influenced by genetic, environmental, microbiological, and immunological factors. The aim of this study was to evaluate the effects of short- and long-term Passiflora edulis peel intake on the antioxidant status, microbiota, and short-chain fatty acids formation in rats with 2,4,6-trinitrobenzenesulphonic acid-induced colitis using two "in vivo" experiments: chronic (prevention) and acute (treatment). The colitis damage score was determined using macroscopic and microscopic analyses. In addition, the antioxidant activity in serum and other tissues (liver and colon) was evaluated. Bifidobacteria, lactobacilli, aerobic bacteria and enterobacteria, and the amount of short-chain fatty acids (acetic, butyric, and propionic acids) in cecum content were counted. Differences in the colon damage scores were observed; P. edulis peel intake improved serum antioxidant status. In the treatment protocol, decreased colon lipid peroxidation, a decreased number of aerobic bacteria and enterobacteria, and an improvement in acetic and butyric acid levels in the feces were observed. An improvement in the bifidobacteria and lactobacilli was observed in the prevention protocol. These results suggested that P. edulis peel can modulate microbiota and could be used as source of fiber and polyphenols in the prevention of oxidative stress through the improvement of serum and tissue antioxidant status.

  16. Structures of microbial communities found in anaerobic batch runs that produce methane from propionic acid--Seeded from full-scale anaerobic digesters above a certain threshold.

    PubMed

    Kim, Woong; Shin, Seung Gu; Han, Gyuseong; Cho, Kyungjin; Hwang, Seokhwan

    2015-11-20

    The volatile fatty acid propionate inhibits anaerobic digestion during organic waste treatments. To examine potential microbial interactions that accelerate propionate oxidation, anaerobic digestion systems seeded with various types of anaerobic sludge were analyzed. Seed samples were collected from 10 different full-scale anaerobic reactors in South Korea. Propionate oxidation was estimated as the methane production rate per gram of propionate used per day. Two domestic sewage sludge showed the highest methane production rate values, 109.1 ± 4.2 and 74.5 ± 8.6 mL CH4/(g propionate ∙ d). A food waste recycling wastewater source exhibited the lowest methane production rate, 33.2 ± 2.6 mL CH4/(g propionate ∙ d). To investigate how the microbial community structure affected propionate oxidation, qualitative molecular analyses were carried out using denaturing gradient gel electrophoresis. Methanosaeta concilii, an aceticlastic methanogen, was detected in most batch runs. Smithella propionica, a unique propionate oxidizer and simultaneous producer of acetate, was found in domestic sewage sludge sources showing the highest methane production rate; in contrast, Desulfobulbus rhabdoformis, a sulfate reducer coupled with the consumption of acetate to be used as a precursor of methane, was observed in food waste recycling wastewater sludge source showing the lowest methane production rate. Thus, we propose that S. propionica, a syntrophic acetate producer using propionate, might cooperate with aceticlastic methanogens for high methane production during anaerobic digestion that included propionate. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Two Pathways of Glutamate Fermentation by Anaerobic Bacteria

    PubMed Central

    Buckel, Wolfgang; Barker, H. A.

    1974-01-01

    Two pathways are involved in the fermentation of glutamate to acetate, butyrate, carbon dioxide, and ammonia—the methylaspartate and the hydroxyglutarate pathways which are used by Clostridium tetanomorphum and Peptococcus aerogenes, respectively. Although these pathways give rise to the same products, they are easily distinguished by different labeling patterns of the butyrate when [4-14C]glutamate is used as substrate. Schmidt degradation of the radioactive butyrate from C. tetanomorphum yielded equally labeled propionate and carbon dioxide, whereas nearly all the radioactivity of the butyrate from P. aerogenes was recovered in the corresponding propionate. This procedure was used as a test for the pathway of glutamate fermentation by 15 strains (9 species) of anaerobic bacteria. The labeling patterns of the butyrate indicate that glutamate is fermented via the methylaspartate pathway by C. tetani, C. cochlearium, and C. saccarobutyricum, and via the hydroxyglutarate pathway by Acidaminococcus fermentans, C. microsporum, Fusobacterium nucleatum, and F. fusiformis. Enzymes specific for each pathway were assayed in crude extracts of the above organisms. 3-Methylaspartase was found only in clostridia which use the methylaspartate pathway, including Clostridium SB4 and C. sticklandii, which probably degrade glutamate to acetate and carbon dioxide by using a second amino acid as hydrogen acceptor. High levels of 2-hydroxyglutarate dehydrogenase were found exclusively in organisms that use the hydroxyglutarate pathway. The data indicate that only two pathways are involved in the fermentation of glutamate by the bacteria analyzed. The methylaspartate pathway appears to be used only by species of Clostridium, whereas the hydroxyglutarate pathway is used by representatives of several genera. PMID:4813895

  18. Growth inhibition of Erwinia amylovora and related Erwinia species by neutralized short‑chain fatty acids.

    PubMed

    Konecki, Katrin; Gernold, Marina; Wensing, Annette; Geider, Klaus

    2013-11-01

    Short-chain fatty acids (SCFAs) are used to preserve food and could be a tool for control of fire blight caused by Erwinia amylovora on apple, pear and related rosaceous plants. Neutralized acids were added to buffered growth media at 0.5–75 mM and tested at pHs ranging from 6.8 to 5.5. Particularly at low pH, SCFAs with a chain length exceeding that of acetic acid such as propionic acid were effective growth inhibitors of E. amylovora possibly due to uptake of free acid and its intracellular accumulation. We also observed high inhibition with monochloroacetic acid. An E. billingiae strain was as sensitive to the acids as E. amylovora or E. tasmaniensis. Fire blight symptoms on pear slices were reduced when the slices were pretreated with neutralized propionic acid. Propionic acid is well water soluble and could be applied in orchards as a control agent for fire blight.

  19. Biokinetics and bacterial communities of propionate oxidizing bacteria in phased anaerobic sludge digestion systems.

    PubMed

    Zamanzadeh, Mirzaman; Parker, Wayne J; Verastegui, Yris; Neufeld, Josh D

    2013-03-15

    Phased anaerobic digestion is a promising technology and may be a potential source of bio-energy production. Anaerobic digesters are widely used for sewage sludge stabilization and thus a better understanding of the microbial process and kinetics may allow increased volatile solids reduction and methane production through robust process operation. In this study, we analyzed the impact of phase separation and operational conditions on the bio-kinetic characteristics and communities of bacteria associated with four phased anaerobic digestion systems. In addition to significant differences between bacterial communities associated with different digester operating temperatures, our results also revealed that bacterial communities in the phased anaerobic digestion systems differed between the 1st and 2nd phase digesters and we identified strong community composition correlations with several measured physicochemical parameters. The maximum specific growth rates of propionate oxidizing bacteria (POB) in the mesophilic and thermophilic 1st phases were 11 and 23.7 mgCOD mgCOD(-1) d(-1), respectively, while those of the mesophilic and thermophilic 2nd-phase digesters were 6.7 and 18.6 mgCOD mgCOD(-1) d(-1), respectively. Hence, the biokinetic characteristics of the POB population were dependent on the digester loading. In addition, we observed that the temperature dependency factor (θ) values were higher for the less heavily loaded digesters as compared to the values obtained for the 1st-phase digesters. Our results suggested the appropriate application of two sets of POB bio-kinetic that reflect the differing growth responses as a function of propionate concentration (and/or organic loading rates). Also, modeling acetogenesis in phased anaerobic sludge digestion systems will be improved considering a population shift in separate phases. On the basis of the bio-kinetic values estimated in various digesters, high levels of propionate in the thermophilic digesters may be best explained by the establishment of POB with low affinities (high K(s)) for propionate. Achieving low levels of propionate with either thermophilic or short HRT digesters is challenging and a relatively long HRT mesophilic digester should be employed for this purpose. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. 21 CFR 582.3081 - Propionic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propionic acid. 582.3081 Section 582.3081 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3081...

  1. Isotopomer enrichment assay for very short chain fatty acids and its metabolic applications.

    PubMed

    Tomcik, Kristyen; Ibarra, Rafael A; Sadhukhan, Sushabhan; Han, Yong; Tochtrop, Gregory P; Zhang, Guo-Fang

    2011-03-01

    The present work illustrated an accurate GC/MS measurement for the low isotopomer enrichment assay of formic acid, acetic acid, propionic aicd, butyric acid, and pentanoic acid. The pentafluorobenzyl bromide derivatives of these very short chain fatty acids have high sensitivity of isotopoic enrichment due to their low natural isotopomer distribution in negative chemical ionization mass spectrometric mode. Pentafluorobenzyl bromide derivatization reaction was optimized in terms of pH, temperature, reaction time, and the amount of pentafluorobenzyl bromide versus sample. The precision, stability, and accuracy of this method for the isotopomer analysis were validated. This method was applied to measure the enrichments of formic acid, acetic acid, and propionic acid in the perfusate from rat liver exposed to Krebs-Ringer bicarbonate buffer only, 0-1mM [3,4-(13)C(2)]-4-hydroxynonanoate, and 0-2mM [5,6,7-(13)C(3)]heptanoate. The enrichments of acetic acid and propionic acid in the perfusate are comparable to the labeling pattern of acetyl-CoA and propionyl-CoA in the rat liver tissues. The enrichment of the acetic acid assay is much more sensitive and precise than the enrichment of acetyl-CoA by LC-MS/MS. The reversibility of propionyl-CoA from succinyl-CoA was confirmed by the low labeling of M1 and M2 of propionic acid from [5,6,7-(13)C(3)]heptanoate perfusates. 2010 Elsevier Inc. All rights reserved.

  2. 2(2,4,5-Trichlorophenoxy) propionic acid (2,4,5-TP)

    Integrated Risk Information System (IRIS)

    2 ( 2,4,5 - Trichlorophenoxy ) propionic acid ( 2,4,5 - TP ) ; CASRN 93 - 72 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Hea

  3. Bacterial community composition and fermentation patterns in the rumen of sika deer (Cervus nippon) fed three different diets.

    PubMed

    Li, Zhipeng; Wright, André-Denis G; Liu, Hanlu; Bao, Kun; Zhang, Tietao; Wang, Kaiying; Cui, Xuezhe; Yang, Fuhe; Zhang, Zhigang; Li, Guangyu

    2015-02-01

    Sika deer (Cervus nippon) rely on microorganisms living in the rumen to convert plant materials into chemical compounds, such as volatile fatty acids (VFAs), but how the rumen bacterial community is affected by different forages and adapt to altered diets remains poorly understood. The present study used 454-pyrosequencing of bacterial 16S ribosomal RNA (rRNA) genes to examine the relationship between rumen bacterial diversity and metabolic phenotypes using three sika deer in a 3 × 3 latin square design. Three sika deer were fed oak leaves (OL), corn stover (CS), or corn silage (CI), respectively. After a 7-day feeding period, when compared to the CS and CI groups, the OL group had a lower proportion of Prevotella spp. and a higher proportion of unclassified bacteria belonging to the families Succinivibrionaceae and Paraprevotellaceae (P<0.05). Meanwhile, the concentration of isobutyrate was significantly lower (P<0.05) in the OL group than in the CS and CI groups. There was no significant change of dominant bacterial genera in the OL group after 28 days of feeding. Conversely, total volatile fatty acids (TVFAs) showed an increase after 28 days of feeding, mainly due to the increasing of acetate, propionate, and valerate (P<0.05). The interplay between bacteria and metabolism in the OL group differed from that in the CS and CI groups, especially for the interaction of TVFAs and acetate/propionate. Overall, the current study suggested that Prevotella spp. played critical roles in the fermentation of feed in the rumen of sika deer. However, the differences in interplay patterns between rumen bacterial community composition and metabolic phenotypes were altered in the native and domesticated diets indicating the changed fermentation patterns in the rumen of sika deer.

  4. Specific substrate-driven changes in human faecal microbiota composition contrast with functional redundancy in short-chain fatty acid production.

    PubMed

    Reichardt, Nicole; Vollmer, Maren; Holtrop, Grietje; Farquharson, Freda M; Wefers, Daniel; Bunzel, Mirko; Duncan, Sylvia H; Drew, Janice E; Williams, Lynda M; Milligan, Graeme; Preston, Thomas; Morrison, Douglas; Flint, Harry J; Louis, Petra

    2018-02-01

    The diet provides carbohydrates that are non-digestible in the upper gut and are major carbon and energy sources for the microbial community in the lower intestine, supporting a complex metabolic network. Fermentation produces the short-chain fatty acids (SCFAs) acetate, propionate and butyrate, which have health-promoting effects for the human host. Here we investigated microbial community changes and SCFA production during in vitro batch incubations of 15 different non-digestible carbohydrates, at two initial pH values with faecal microbiota from three different human donors. To investigate temporal stability and reproducibility, a further experiment was performed 1 year later with four of the carbohydrates. The lower pH (5.5) led to higher butyrate and the higher pH (6.5) to more propionate production. The strongest propionigenic effect was found with rhamnose, followed by galactomannans, whereas fructans and several α- and β-glucans led to higher butyrate production. 16S ribosomal RNA gene-based quantitative PCR analysis of 22 different microbial groups together with 454 sequencing revealed significant stimulation of specific bacteria in response to particular carbohydrates. Some changes were ascribed to metabolite cross-feeding, for example, utilisation by Eubacterium hallii of 1,2-propanediol produced from fermentation of rhamnose by Blautia spp. Despite marked inter-individual differences in microbiota composition, SCFA production was surprisingly reproducible for different carbohydrates, indicating a level of functional redundancy. Interestingly, butyrate formation was influenced not only by the overall % butyrate-producing bacteria in the community but also by the initial pH, consistent with a pH-dependent shift in the stoichiometry of butyrate production.

  5. Genomes of rumen bacteria encode atypical pathways for fermenting hexoses to short-chain fatty acids.

    PubMed

    Hackmann, Timothy J; Ngugi, David Kamanda; Firkins, Jeffrey L; Tao, Junyi

    2017-11-01

    Bacteria have been thought to follow only a few well-recognized biochemical pathways when fermenting glucose or other hexoses. These pathways have been chiseled in the stone of textbooks for decades, with most sources rendering them as they appear in the classic 1986 text by Gottschalk. Still, it is unclear how broadly these pathways apply, given that they were established and delineated biochemically with only a few model organisms. Here, we show that well-recognized pathways often cannot explain fermentation products formed by bacteria. In the most extensive analysis of its kind, we reconstructed pathways for glucose fermentation from genomes of 48 species and subspecies of bacteria from one environment (the rumen). In total, 44% of these bacteria had atypical pathways, including several that are completely unprecedented for bacteria or any organism. In detail, 8% of bacteria had an atypical pathway for acetate formation; 21% of bacteria had an atypical pathway for propionate or succinate formation; 6% of bacteria had an atypical pathway for butyrate formation and 33% of bacteria had an atypical or incomplete Embden-Meyerhof-Parnas pathway. This study shows that reconstruction of metabolic pathways - a common goal of omics studies - could be incorrect if well-recognized pathways are used for reference. Furthermore, it calls for renewed efforts to delineate fermentation pathways biochemically. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Pre- and Neonatal Exposure to Lipopolysaccharide or the Enteric Metabolite, Propionic Acid, Alters Development and Behavior in Adolescent Rats in a Sexually Dimorphic Manner

    PubMed Central

    Foley, Kelly A.; Ossenkopp, Klaus-Peter; Kavaliers, Martin; MacFabe, Derrick F.

    2014-01-01

    Alterations in the composition of the gut microbiome and/or immune system function may have a role in the development of autism spectrum disorders (ASD). The current study examined the effects of prenatal and early life administration of lipopolysaccharide (LPS), a bacterial mimetic, and the short chain fatty acid, propionic acid (PPA), a metabolic fermentation product of enteric bacteria, on developmental milestones, locomotor activity, and anxiety-like behavior in adolescent male and female offspring. Pregnant Long-Evans rats were subcutaneously injected once a day with PPA (500 mg/kg) on gestation days G12–16, LPS (50 µg/kg) on G15–16, or vehicle control on G12–16 or G15–16. Male and female offspring were injected with PPA (500 mg/kg) or vehicle twice a day, every second day from postnatal days (P) 10–18. Physical milestones and reflexes were monitored in early life with prenatal PPA and LPS inducing delays in eye opening. Locomotor activity and anxiety were assessed in adolescence (P40–42) in the elevated plus maze (EPM) and open-field. Prenatal and postnatal treatments altered behavior in a sex-specific manner. Prenatal PPA decreased time spent in the centre of the open-field in males and females while prenatal and postnatal PPA increased anxiety behavior on the EPM in female rats. Prenatal LPS did not significantly influence those behaviors. Evidence for the double hit hypothesis was seen as females receiving a double hit of PPA (prenatal and postnatal) displayed increased repetitive behavior in the open-field. These results provide evidence for the hypothesis that by-products of enteric bacteria metabolism such as PPA may contribute to ASD, altering development and behavior in adolescent rats similar to that observed in ASD and other neurodevelopmental disorders. PMID:24466331

  7. The intestinal fatty acid propionate inhibits Salmonella invasion through the post-translational control of HilD

    USDA-ARS?s Scientific Manuscript database

    For Salmonella to cause disease, it must first invade the intestinal epithelium using genes encoded within Salmonella Pathogenicity Island 1 (SPI1). Previous work has shown that propionate, a short chain fatty acid abundant in the intestine of animal hosts, negatively regulates SPI1 in vitro. Here...

  8. Fixed Drug Eruption Due to Selective Hypersensitivity to Naproxen with Tolerance to other Propionic Acid NSAIDs.

    PubMed

    Noguerado-Mellado, Blanca; Gamboa, Abdonias R; Perez-Ezquerra, Patricia R; Cabeza, Cristina M; Fernandez, Roberto P; De Barrio Fernandez, Manuel

    2016-01-01

    Naproxen is a non-steroidal anti-inflammatory drug (NSAID), belonging to propionic acid group, and its chemical structure is a 6-metoxi-metil-2-naftalenoacetic acid. Fixed drug eruptions (FDE) have been rarely reported. A 38-year-old woman referred that after 2 hours of taking 2 tablets of naproxen for a headache, she developed several edematous and dusky-red macules, one on right forearm and the other two in both thighs and she was diagnosed with FDE probably due to naproxen. We performed patch testing (PT) (Nonweven Patch Test Strips Curatest® Lohman & Rauscher International, Rangsdorf, Germany), with ibuprofen (5% Petrolatum), ketoprofen (2.5% Petrolatum), naproxen and nabumetone (both 10% in DMSO) on the residual lesion of the forearm with naproxen and in both thighs with ibuprofen, ketoprofen and nabumetone. Readings at day 1 (D1) and day 2 (D2) showed negative results to ibuprofen, ketoprofen and nabumetone, but were positive to naproxen in D1. A single blind oral challenge test (SBOCT) with other propionic acid derivates were performed in order to check for crossreactivity between them: ibuprofen, ketoprofen and nabumetone were administered and all drugs were well tolerated. In our patient PT confirmed the diagnosis and allowed us to study the cross-reactivity between NSAIDs of the same group, and confirmed by SBOCT. Cross-reactivity between propionic acid derivatives was studied. This is a case of hypersensitivity to naproxen with good tolerance to other propionic acids NSAIDs (ibuprofen and ketoprofen) and nabumetone, confirmed by PT and SBOCT. Some relavent patents for fixed drug eruption are discussed.

  9. The physicochemical characteristics and anaerobic degradability of desiccated coconut industry waste water.

    PubMed

    Chanakya, H N; Khuntia, Himanshu Kumar; Mukherjee, Niranjan; Aniruddha, R; Mudakavi, J R; Thimmaraju, Preeti

    2015-12-01

    Desiccated coconut industries (DCI) create various intermediates from fresh coconut kernel for cosmetic, pharmaceutical and food industries. The mechanized and non-mechanized DCI process between 10,000 and 100,000 nuts/day to discharge 6-150 m(3) of malodorous waste water leading to a discharge of 264-6642 kg chemical oxygen demand (COD) daily. In these units, three main types of waste water streams are coconut kernel water, kernel wash water and virgin oil waste water. The effluent streams contain lipids (1-55 g/l), suspended solids (6-80 g/l) and volatile fatty acids (VFA) at concentrations that are inhibitory to anaerobic bacteria. Coconut water contributes to 20-50% of the total volume and 50-60% of the total organic loads and causes higher inhibition of anaerobic bacteria with an initial lag phase of 30 days. The lagooning method of treatment widely adopted failed to appreciably treat the waste water and often led to the accumulation of volatile fatty acids (propionic acid) along with long-chain unsaturated free fatty acids. Biogas generation during biological methane potential (BMP) assay required a 15-day adaptation time, and gas production occurred at low concentrations of coconut water while the other two streams did not appear to be inhibitory. The anaerobic bacteria can mineralize coconut lipids at concentrations of 175 mg/l; however; they are severely inhibited at a lipid level of ≥350 mg/g bacterial inoculum. The modified Gompertz model showed a good fit with the BMP data with a simple sigmoid pattern. However, it failed to fit experimental BMP data either possessing a longer lag phase and/or diauxic biogas production suggesting inhibition of anaerobic bacteria.

  10. Compromised Lactobacillus helveticus starter activity in the presence of facultative heterofermentative Lactobacillus casei DPC6987 results in atypical eye formation in Swiss-type cheese.

    PubMed

    O'Sullivan, Daniel J; McSweeney, Paul L H; Cotter, Paul D; Giblin, Linda; Sheehan, Jeremiah J

    2016-04-01

    Nonstarter lactic acid bacteria are commonly implicated in undesirable gas formation in several varieties, including Cheddar, Dutch-, and Swiss-type cheeses, primarily due to their ability to ferment a wide variety of substrates. This effect can be magnified due to factors that detrimentally affect the composition or activity of starter bacteria, resulting in the presence of greater than normal amounts of fermentable carbohydrates and citrate. The objective of this study was to determine the potential for a facultatively heterofermentative Lactobacillus (Lactobacillus casei DPC6987) isolated from a cheese plant environment to promote gas defects in the event of compromised starter activity. A Swiss-type cheese was manufactured, at pilot scale and in triplicate, containing a typical starter culture (Streptococcus thermophilus and Lactobacillus helveticus) together with propionic acid bacteria. Lactobacillus helveticus populations were omitted in certain vats to mimic starter failure. Lactobacillus casei DPC6987 was added to each experimental vat at 4 log cfu/g. Cheese compositional analysis and X-ray computed tomography revealed that the failure of starter bacteria, in this case L. helveticus, coupled with the presence of a faculatively heterofermentative Lactobacillus (L. casei) led to excessive eye formation during ripening. The availability of excess amounts of lactose, galactose, and citrate during the initial ripening stages likely provided the heterofermentative L. casei with sufficient substrates for gas formation. The accrual of these fermentable substrates was notable in cheeses lacking the L. helveticus starter population. The results of this study are commercially relevant, as they demonstrate the importance of viability of starter populations and the control of specific nonstarter lactic acid bacteria to ensure appropriate eye formation in Swiss-type cheese. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Conjugated fatty acids and methane production by rumen microbes when incubated with linseed oil alone or mixed with fish oil and/or malate.

    PubMed

    Li, Xiang Z; Gao, Qing S; Yan, Chang G; Choi, Seong H; Shin, Jong S; Song, Man K

    2015-08-01

    We hypothesized that manipulating metabolism with fish oil and malate as a hydrogen acceptor would affect the biohydrogenation process of α-linolenic acid by rumen microbes. This study was to examine the effect of fish oil and/or malate on the production of conjugated fatty acids and methane (CH4 ) by rumen microbes when incubated with linseed oil. Linseed oil (LO), LO with fish oil (LO-FO), LO with malate (LO-MA), or LO with fish oil and malate (LO-FO-MA) was added to diluted rumen fluid, respectively. The LO-MA and LO-FO-MA increased pH and propionate concentration compared to the other treatments. LO-MA and LO-FO-MA reduced CH4 production compared to LO. LO-MA and LO-FO-MA increased the contents of c9,t11-conjugated linoleic acid (CLA) and c9,t11,c15-conjugated linolenic acid (CLnA) compared to LO. The content of malate was rapidly reduced while that of lactate was reduced in LO-MA and LO-FO-MA from 3 h incubation time. The fold change of the quantity of methanogen related to total bacteria was decreased at both 3 h and 6 h incubation times in all treatments compared to the control. Overall data indicate that supplementation of combined malate and/or fish oil when incubated with linseed oil, could depress methane generation and increase production of propionate, CLA and CLnA under the conditions of the current in vitro study. © 2015 Japanese Society of Animal Science.

  12. Intravenous lipid infusion affects dry matter intake, methane yield, and rumen bacteria structure in late-lactating Holstein cows.

    PubMed

    Lamp, Ole; Reyer, Henry; Otten, Winfried; Nürnberg, Gerd; Derno, Michael; Wimmers, Klaus; Metges, Cornelia C; Kuhla, Björn

    2018-03-28

    Increasing the dietary fat content of ruminant diets decreases methane (CH 4 ) production. This effect is caused by the toxic properties of fatty acids on rumen microbial populations, coating of feed particles diminishing the accessibility for microbes, and a reduction in dry matter intake (DMI). The latter effect is caused by postabsorptive long-chain fatty acids eliciting anorexic signaling; however, whether circulating long-chain fatty acids affect rumen CH 4 production alike is unknown. To approach this question, 5 rumen-cannulated Holstein cows in late lactation received 2 jugular catheters and were kept in respiration chambers to measure CH 4 production and DMI for 48 h. In a crossover design, cows were intravenously infused with a 20% lipid emulsion (LIPO) or 0.9% NaCl (CON). The LIPO cows received 2.1 kg of triglycerides/d [0.152 ± 0.007 g of triglycerides/(kg of BW × h) -1 ] consisting of 12.1% palmitic acid, 4.2% stearic acid, 31.1% oleic acid, and 52.7% linoleic acid. Blood and rumen fluid samples were taken hourly during the day. Results showed that LIPO compared with CON infusion increased plasma triglyceride as well as free fatty acid and serotonin concentrations but reduced the proportion of de novo synthesized milk fatty acids (sum of C6 to C16). Daily CH 4 production and DMI were lower, whereas daily CH 4 yield (CH 4 /DMI) was greater in LIPO than CON cows, although CH 4 yield decreased from d 1 to d 2 by 2 to 14% in LIPO-infused cows only. This effect was associated with a higher (acetate + butyrate)/propionate ratio, tending lower propionate concentrations between 24 and 34 h of infusion, reduced relative abundances of genera belonging to Succinivibrio, Ruminococcaceae, and Ruminiclostridium, and greater relative Bacteroidetes genus abundances in the rumen. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Mechanistic Insights into the Catalytic Oxidation of Carboxylic Acids on Au/TiO 2: Partial Oxidation of Propionic and Butyric Acid to Gold Ketenylidene through Unsaturated Acids

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

    McEntee, Monica; Tang, Wenjie; Neurock, Matthew

    Here, the partial oxidation of model C 2–C 4 (acetic, propionic, and butyric) carboxylic acids on Au/TiO 2 catalysts consisting of Au particles ~3 nm in size was investigated using transmission infrared spectroscopy and density functional theory. All three acids readily undergo oxidative dehydrogenation on Au/TiO 2. Propionic and butyric acid dehydrogenate at the C2–C3 positions, whereas acetic acid dehydrogenates at the C1–C2 position. The resulting acrylate and crotonate intermediates are subsequently oxidized to form β-keto acids that decarboxylate. All three acids form a gold ketenylidene intermediate, Au 2C=C=O, along the way to their full oxidation to form CO 2.more » Infrared measurements of Au 2C=C=O formation as a function of time provides a surface spectroscopic probe of the kinetics for the activation and oxidative dehydrogenation of the alkyl groups in the carboxylate intermediates that form.« less

  14. Mechanistic Insights into the Catalytic Oxidation of Carboxylic Acids on Au/TiO 2: Partial Oxidation of Propionic and Butyric Acid to Gold Ketenylidene through Unsaturated Acids

    DOE PAGES

    McEntee, Monica; Tang, Wenjie; Neurock, Matthew; ...

    2014-12-12

    Here, the partial oxidation of model C 2–C 4 (acetic, propionic, and butyric) carboxylic acids on Au/TiO 2 catalysts consisting of Au particles ~3 nm in size was investigated using transmission infrared spectroscopy and density functional theory. All three acids readily undergo oxidative dehydrogenation on Au/TiO 2. Propionic and butyric acid dehydrogenate at the C2–C3 positions, whereas acetic acid dehydrogenates at the C1–C2 position. The resulting acrylate and crotonate intermediates are subsequently oxidized to form β-keto acids that decarboxylate. All three acids form a gold ketenylidene intermediate, Au 2C=C=O, along the way to their full oxidation to form CO 2.more » Infrared measurements of Au 2C=C=O formation as a function of time provides a surface spectroscopic probe of the kinetics for the activation and oxidative dehydrogenation of the alkyl groups in the carboxylate intermediates that form.« less

  15. Water-enhanced solvation of organics

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

    Lee, Jane H.

    1993-07-01

    Water-enhanced solvation (WES) was explored for Lewis acid solutes in Lewis base organic solvents, to develop cheap extract regeneration processes. WES for solid solutes was determined from ratios of solubilities of solutes in water-sat. and low-water solvent; both were determined from solid-liquid equilibrium. Vapor-headspace analysis was used to determine solute activity coefficients as function of organic phase water concentration. WES magnitudes of volatile solutes were normalized, set equal to slope of log γ s vs x w/x s curve. From graph shape Δ(log γ s) represents relative change in solute activity coefficient. Solutes investigated by vapor-headspace analysis were acetic acid,more » propionic acid, ethanol, 1,2-propylene glycol, 2,3-butylene glycol. Monocarboxylic acids had largest decrease in activity coefficient with water addition followed by glycols and alcohols. Propionic acid in cyclohexanone showed greatest water-enhancement Δ(log γ acid)/Δ(x w/x acid) = -0.25. In methylcyclohexanone, the decrease of the activity coefficient of propionic acid was -0.19. Activity coefficient of propionic acid in methylcyclohexanone stopped decreasing once the water reached a 2:1 water to acid mole ratio, implying a stoichiometric relation between water, ketone, and acid. Except for 2,3-butanediol, activity coefficients of the solutes studied decreased monotonically with water content. Activity coefficient curves of ethanol, 1,2-propanediol and 2,3-butanediol did not level off at large water/solute mole ratio. Solutes investigated by solid-liquid equilibrium were citric acid, gallic acid, phenol, xylenols, 2-naphthol. Saturation concentration of citric acid in anhydrous butyl acetate increased from 0.0009 to 0.087 mol/L after 1.3 % (g/g) water co-dissolved into organic phase. Effect of water-enhanced solvation for citric acid is very large but very small for phenol and its derivatives.« less

  16. Microbial Production of Short Chain Fatty Acids from Lignocellulosic Biomass: Current Processes and Market.

    PubMed

    Baumann, Ivan; Westermann, Peter

    2016-01-01

    Biological production of organic acids from conversion of biomass derivatives has received increased attention among scientists and engineers and in business because of the attractive properties such as renewability, sustainability, degradability, and versatility. The aim of the present review is to summarize recent research and development of short chain fatty acids production by anaerobic fermentation of nonfood biomass and to evaluate the status and outlook for a sustainable industrial production of such biochemicals. Volatile fatty acids (VFAs) such as acetic acid, propionic acid, and butyric acid have many industrial applications and are currently of global economic interest. The focus is mainly on the utilization of pretreated lignocellulosic plant biomass as substrate (the carbohydrate route) and development of the bacteria and processes that lead to a high and economically feasible production of VFA. The current and developing market for VFA is analyzed focusing on production, prices, and forecasts along with a presentation of the biotechnology companies operating in the market for sustainable biochemicals. Finally, perspectives on taking sustainable product of biochemicals from promise to market introduction are reviewed.

  17. Microbial Production of Short Chain Fatty Acids from Lignocellulosic Biomass: Current Processes and Market

    PubMed Central

    Baumann, Ivan

    2016-01-01

    Biological production of organic acids from conversion of biomass derivatives has received increased attention among scientists and engineers and in business because of the attractive properties such as renewability, sustainability, degradability, and versatility. The aim of the present review is to summarize recent research and development of short chain fatty acids production by anaerobic fermentation of nonfood biomass and to evaluate the status and outlook for a sustainable industrial production of such biochemicals. Volatile fatty acids (VFAs) such as acetic acid, propionic acid, and butyric acid have many industrial applications and are currently of global economic interest. The focus is mainly on the utilization of pretreated lignocellulosic plant biomass as substrate (the carbohydrate route) and development of the bacteria and processes that lead to a high and economically feasible production of VFA. The current and developing market for VFA is analyzed focusing on production, prices, and forecasts along with a presentation of the biotechnology companies operating in the market for sustainable biochemicals. Finally, perspectives on taking sustainable product of biochemicals from promise to market introduction are reviewed. PMID:27556042

  18. Sulfate addition as an effective method to improve methane fermentation performance and propionate degradation in thermophilic anaerobic co-digestion of coffee grounds, milk and waste activated sludge with AnMBR.

    PubMed

    Li, Qian; Li, Yu-You; Qiao, Wei; Wang, Xiaochang; Takayanagi, Kazuyuki

    2015-06-01

    This study was conducted to investigate the effects of sulfate on propionate degradation and higher organic loading rate (OLR) achievement in a thermophilic AnMBR for 373days using coffee grounds, milk and waste activated sludge (WAS) as the co-substrate. Without the addition of sulfate, the anaerobic system failed at an OLR of 14.6g-COD/L/d, with propionate accumulating to above 2.23g-COD/L, and recovery by an alkalinity supplement was not successful. After sulfate was added into substrates at a COD/SO4(2-) ratio of 200:1 to 350:1, biogas production increased proportionally with OLR increasing from 4.06 to 15.2g-COD/L/d. Propionic acid was maintained at less than 100mg-COD/L due to the effective conversion of propionic acid to methane after the sulfate supplement was added. The long-term stable performance of the AnMBR indicated that adding sulfate was beneficial for the degradation of propionate and achieving a higher OLR under the thermophilic condition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Propionate absorbed from the colon acts as gluconeogenic substrate in a strict carnivore, the domestic cat (Felis catus).

    PubMed

    Verbrugghe, A; Hesta, M; Daminet, S; Polis, I; Holst, J J; Buyse, J; Wuyts, B; Janssens, G P J

    2012-12-01

    In six normal-weight and six obese cats, the metabolic effect of propionate absorbed from the colon was assessed. Two colonic infusions were tested in a crossover design with intervals of 4 weeks. The test solution contained 4 mmol sodium propionate per kg ideal body weight in a 0.2% NaCl solution. Normal saline was given as control solution. Solutions were infused into the hindgut over 30 min. Blood samples were obtained prior to and at various time points after starting the infusion. As body condition did not affect evaluated parameters, all data were pooled. Plasma glucose concentrations showed differences neither over time nor during or after infusion with propionate or control. Plasma amino acid concentrations rose over time (p < 0.001), but were similar for both infusions. Plasma propionylcarnitine rose markedly towards the end of the propionate infusion and decreased afterwards (p < 0.001), whereas 3-hydroxy-3-methylglutarylcarnitine was lower 30 (p = 0.005) and 60 min (p = 0.032) after ending propionate infusions and acetylcarnitine tended to fall at the same time points (p = 0.079; p = 0.080), suggesting inhibition of gluconeogenesis from pyruvate and amino acids, but initiation of propionate-induced gluconeogenesis. In conclusion, propionate absorbed from the colon is hypothesized to act as gluconeogenic substrate, regardless of the cat's body condition. © 2011 Blackwell Verlag GmbH.

  20. The use of fermentation liquid of wastewater primary sedimentation sludge as supplemental carbon source for denitrification based on enhanced anaerobic fermentation.

    PubMed

    Liu, Feng; Tian, Yu; Ding, Yi; Li, Zhipeng

    2016-11-01

    Wastewater primary sedimentation sludge was prepared into fermentation liquid as denitrification carbon source, and the main components of fermentation liquid was short-chain volatile fatty acids. Meanwhile, the acetic acid and propionic acid respectively accounted for about 29.36% and 26.56% in short-chain volatile fatty acids. The performance of fermentation liquid, methanol, acetic acid, propionic acid and glucose used as sole carbon source were compared. It was found that the denitrification rate with fermentation liquid as carbon source was 0.17mgNO3(-)-N/mg mixed liquor suspended solid d, faster than that with methanol, acetic acid, and propionic acid as sole carbon source, and lower than that with glucose as sole carbon source. For the fermentation liquid as carbon source, the transient accumulation of nitrite was insignificantly under different initial total nitrogen concentration. Therefore, the use of fermentation liquid for nitrogen removal could improve denitrification rate, and reduce nitrite accumulation in denitrification process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Enhanced Bio-hydrogen Production from Protein Wastewater by Altering Protein Structure and Amino Acids Acidification Type

    PubMed Central

    Xiao, Naidong; Chen, Yinguang; Chen, Aihui; Feng, Leiyu

    2014-01-01

    Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subsequent fermentation stage as it caused the unfolding of protein, damaged the protein hydrogen bonding networks, and destroyed the disulfide bridges, which increased the susceptibility of protein to protease. Moreover, pH 10 fermentation produced more acetic but less propionic acid during the anaerobic fermentation of amino acids, which was consistent with the theory of fermentation type affecting hydrogen production. Further analyses of the critical enzymes, genes, and microorganisms indicated that the activity and abundance of hydrogen producing bacteria in the pH 10 fermentation reactor were greater than those in the control. PMID:24495932

  2. Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type.

    PubMed

    Xiao, Naidong; Chen, Yinguang; Chen, Aihui; Feng, Leiyu

    2014-02-05

    Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subsequent fermentation stage as it caused the unfolding of protein, damaged the protein hydrogen bonding networks, and destroyed the disulfide bridges, which increased the susceptibility of protein to protease. Moreover, pH 10 fermentation produced more acetic but less propionic acid during the anaerobic fermentation of amino acids, which was consistent with the theory of fermentation type affecting hydrogen production. Further analyses of the critical enzymes, genes, and microorganisms indicated that the activity and abundance of hydrogen producing bacteria in the pH 10 fermentation reactor were greater than those in the control.

  3. Enhanced Bio-hydrogen Production from Protein Wastewater by Altering Protein Structure and Amino Acids Acidification Type

    NASA Astrophysics Data System (ADS)

    Xiao, Naidong; Chen, Yinguang; Chen, Aihui; Feng, Leiyu

    2014-02-01

    Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subsequent fermentation stage as it caused the unfolding of protein, damaged the protein hydrogen bonding networks, and destroyed the disulfide bridges, which increased the susceptibility of protein to protease. Moreover, pH 10 fermentation produced more acetic but less propionic acid during the anaerobic fermentation of amino acids, which was consistent with the theory of fermentation type affecting hydrogen production. Further analyses of the critical enzymes, genes, and microorganisms indicated that the activity and abundance of hydrogen producing bacteria in the pH 10 fermentation reactor were greater than those in the control.

  4. Bacterial carbohydrate-degrading capacity in foal faeces: changes from birth to pre-weaning and the impact of maternal supplementation with fermented feed products.

    PubMed

    Faubladier, Céline; Julliand, Véronique; Danel, Justine; Philippeau, Christelle

    2013-09-28

    The present study aimed at (1) describing age-related changes in faecal bacterial functional groups involved in carbohydrate degradation and in their activities in foals (n 10) from birth (day (d) 0) to 6 months (d180) and (2) investigating the effect of maternal supplementation (five mares per treatment) from d - 45 to d60 with fermented feed products on response trends over time of the foal bacterial carbohydratedegrading capacity. Maternal supplementation with fermented feed products stimulated foal growth from d0 to d60 and had an impact on the establishment of some digestive bacterial groups and their activities in foals from d0 to d5 but not in the longer term. Irrespective of the maternal treatment, total bacteria, total anaerobic, lactate-utilising and amylolytic bacteria were established immediately after birth (P<0·05) and were active as shown by the significant increase in total volatile fatty acids. In the foals of supplemented mares, total anaerobes and lactate utilisers were established rapidly between d0 and d2 (P=0·021 and 0·066, respectively) and the increase in the percentage of propionate occurred earlier (P=0·013). Maternal supplementation had no effect on the establishment of fibrolytic bacteria and their activity. Cellulolytic bacteria and Fibrobacter succinogenes first appeared at d2 and d5, and increased progressively, reaching stable values at d30 and d60, respectively. From the second week of life, the increase in the molar percentage of acetate and the ratio (acetate + butyrate):propionate (P<0·05) suggested that fibrolytic activity had begun. From d60, only minor changes in bacterial composition and activities occurred, showing that the bacterial carbohydrate-degrading capacity was established at 2 months of age.

  5. Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/Hyperbranched Polyester Blends

    DTIC Science & Technology

    1999-01-01

    interfacial tension between the PE and polystyrene phases. This was brought about by the chemical interaction between the acidic anhydride groups in the...multiple 2,2 dimethylol propionic acid (C5H10O4) chain extenders or repeat units. 11 Core HO \\ HO’ /■ J OH V *OH Pentaerythritol Chain Extender...O 2,2 - Dimethylol propionic acid Figure 11. HBP Building Blocks. These materials were supplied in small quantities with little technical data. The

  6. Alkyl polyglucose enhancing propionic acid enriched short-chain fatty acids production during anaerobic treatment of waste activated sludge and mechanisms.

    PubMed

    Luo, Jingyang; Feng, Leiyu; Chen, Yinguang; Sun, Han; Shen, Qiuting; Li, Xiang; Chen, Hong

    2015-04-15

    Adding alkyl polyglucose (APG) into an anaerobic treatment system of waste activated sludge (WAS) was reported to remarkably improve the production of short-chain fatty acids (SCFAs), especially propionic acid via simultaneously accelerating solubilization and hydrolysis, enhancing acidification, inhibiting methanogenesis and balancing carbon to nitrogen (C/N) ratio of substrate. Not only the production of SCFAs, especially propionic acid, was significantly improved by APG, but also the feasible operation time was shortened. The SCFAs yield at 0.3 g APG per gram of total suspended solids (TSS) within 4 d was 2988 ± 60 mg chemical oxygen demand (COD) per liter, much higher than that those from sole WAS or sole WAS plus sole APG. The corresponding yield of propionic acid was 1312 ± 25 mg COD/L, 7.9-fold of sole WAS. Mechanism investigation showed that during anaerobic treatment of WAS in the presence of APG both the solubilization and hydrolysis were accelerated and the acidification was enhanced, while the methanogenesis was inhibited. Moreover, the activities of key enzymes involved in WAS hydrolysis and acidification were improved through the adjustment of C/N ratio of substrates with APG. The abundance of microorganisms responsible for organic compounds hydrolysis and SCFAs production was also observed to be greatly enhanced with APG via 454 high-throughput pyrosequencing analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Fermentation of wet-exploded corn stover for the production of volatile fatty acids.

    PubMed

    Murali, Nanditha; Fernandez, Sebastian; Ahring, Birgitte Kiaer

    2017-03-01

    Volatile fatty acids (VFA) have been used as platform molecules for production of biofuels and bioproducts. In the current study, we examine the VFA production from wet-exploded corn stover through anaerobic fermentation using rumen bacteria. The total VFA yield (acetic acid equivalents) was found to increase from 22.8g/L at 2.5% total solids (TS) to 40.8g/L at 5% TS. It was found that the acetic acid concentration increased from 10g/L to 22g/L at 2.5% and 5% TS, respectively. An increased propionic acid production was seen between day 10 and 20 at 5% TS. Valeric acid (4g/L) was produced at 5% TS and not at 2.5% TS. Composition analysis showed that 50% of the carbohydrates were converted to VFA at 5% TS and 33% at 2.5% TS. Our results show that rumen fermentation of lignocellulosic biomass after wet explosion can produce high concentrations of VFA without addition of external enzymes of importance for the process economics of lignocellulosic biorefineries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Malt in combination with Lactobacillus rhamnosus increases concentrations of butyric acid in the distal colon and serum in rats compared with other barley products but decreases viable counts of cecal bifidobacteria.

    PubMed

    Bränning, Camilla E; Nyman, Margareta E

    2011-01-01

    Several substances, including glutamine and propionic acid but in particular butyric acid, have been proposed to be important for colonic health. β-Glucans lead to the formation of comparatively high amounts of butyric acid, and germinated barley foodstuff obtained from brewer's spent grain (BSG), containing high amounts of β-glucans and glutamine, has been reported to reduce the inflammatory response in the colon of patients with ulcerative colitis. The present study examines how 3 barley products, whole grain barley, malt, and BSG, affect SCFA in the hindgut and serum of rats and whether the addition of Lactobacillus rhamnosus 271 to each of these diets would have further effects. Amino acids in plasma and the cecal composition of the microbiota were also analyzed. The butyric acid concentration in the distal colon and serum was higher in the malt groups than in the other groups as was the serum concentration of propionic acid. The concentrations of propionic and butyric acids were higher in the cecum and serum of rats given L. rhamnosus than in those not given this strain. The proportion of plasma glutamine and the cecal number of bifidobacteria were lower in the malt groups than in the other groups. L. rhamnosus decreased the number of cecal bifidobacteria, whereas plasma glutamine was unaffected. We conclude that malt together with L. rhamnosus 271 had greater effects on propionic and butyric acid concentrations in rats than the other barley products. This is interesting when developing food with effects on colonic health.

  9. Propionate induces cell swelling and K+ accumulation in shark rectal gland

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

    Feldman, G.M.; Ziyadeh, F.N.; Mills, J.W.

    1989-08-01

    Small organic anions have been reported to induce cell solute accumulation and swelling. To investigate the mechanism of swelling, we utilized preparations of rectal gland cells from Squalus acanthias incubated in medium containing propionate. Propionate causes cells to swell by diffusing across membranes in its nonionic form, acidifying cell contents, and activating the Na+-H+ antiporter. The Na+-H+ exchange process tends to correct intracellular pH (pHi), and thus it maintains a favorable gradient for propionic acid diffusion and allows propionate to accumulate. Activation of the Na+-H+ antiport also facilitates Na+ entry into the cell and Nai accumulation. At the same timemore » Na+-K+-ATPase activity, unaffected by propionate, replaces Nai with Ki, whereas the K+ leak rate, decreased by propionate, allows Ki to accumulate. As judged by {sup 86}Rb+ efflux, the reduction in K+ leak was not due to propionate-induced cell acidification or reduction in Cli concentration. Despite inducing cell swelling, propionate did not disrupt cell structural elements and F actin distribution along cell membranes.« less

  10. Microbiome-host systems interactions: protective effects of propionate upon the blood-brain barrier.

    PubMed

    Hoyles, Lesley; Snelling, Tom; Umlai, Umm-Kulthum; Nicholson, Jeremy K; Carding, Simon R; Glen, Robert C; McArthur, Simon

    2018-03-21

    Gut microbiota composition and function are symbiotically linked with host health and altered in metabolic, inflammatory and neurodegenerative disorders. Three recognised mechanisms exist by which the microbiome influences the gut-brain axis: modification of autonomic/sensorimotor connections, immune activation, and neuroendocrine pathway regulation. We hypothesised interactions between circulating gut-derived microbial metabolites, and the blood-brain barrier (BBB) also contribute to the gut-brain axis. Propionate, produced from dietary substrates by colonic bacteria, stimulates intestinal gluconeogenesis and is associated with reduced stress behaviours, but its potential endocrine role has not been addressed. After demonstrating expression of the propionate receptor FFAR3 on human brain endothelium, we examined the impact of a physiologically relevant propionate concentration (1 μM) on BBB properties in vitro. Propionate inhibited pathways associated with non-specific microbial infections via a CD14-dependent mechanism, suppressed expression of LRP-1 and protected the BBB from oxidative stress via NRF2 (NFE2L2) signalling. Together, these results suggest gut-derived microbial metabolites interact with the BBB, representing a fourth facet of the gut-brain axis that warrants further attention.

  11. Media for the isolation and enumeration of bifidobacteria in dairy products.

    PubMed

    Roy, D

    2001-09-28

    Bifidobacteria are commonly used for the production of fermented milks, alone or in combination with other lactic acid bacteria. Bifidobacteria populations in fermented milks should be over 10(6) bifidobacteria/g at the time of consumption of strain added to the product. Hence, rapid and reliable methods are needed to routinely determine the initial inoculum and to estimate the storage time period bifidobacteria remain viable. Plate count methods are still preferable for quality control measurements in dairy products. It is, therefore, necessary to have a medium that selectively promotes the growth of bifidobacteria, whereas other bacteria are suppressed. The present paper is an overview of media and methods including summaries of published comparisons between different selective media. Culture media for bifidobacteria may be divided into basal, elective, differential and selective culture medium. Non-selective media are useful for routine enumeration of bifidobacteria when present in non-fermented milks. Reinforced Clostridial Agar and De Man Rogosa Sharpe (MRS) supplemented with cysteine and agar available commercially are the media of choice for industrial quality control laboratories. Several media for selective or differential isolation have been described for enumeration of bifidobacteria from other lactic acid bacteria. From the large number of selective media available, it can be concluded that there is no standard medium for the detection of bifidobacteria. However, Columbia agar base media supplemented with lithium chloride and sodium propionate and MRS medium supplemented with neomycin, paromomycin, nalidixic acid and lithium chloride can be recommended for selective enumeration of bifidobacteria in dairy products.

  12. Combining selected immunomodulatory Propionibacterium freudenreichii and Lactobacillus delbrueckii strains: Reverse engineering development of an anti-inflammatory cheese.

    PubMed

    Plé, Coline; Breton, Jérôme; Richoux, Romain; Nurdin, Marine; Deutsch, Stéphanie-Marie; Falentin, Hélène; Hervé, Christophe; Chuat, Victoria; Lemée, Riwanon; Maguin, Emmanuelle; Jan, Gwénaël; Van de Guchte, Maarten; Foligné, Benoit

    2016-04-01

    Inflammatory bowel disease (IBD) constitutes a growing public health concern in western countries. Bacteria with anti-inflammatory properties are lacking in the dysbiosis accompanying IBD. Selected strains of probiotic bacteria with anti-inflammatory properties accordingly alleviate symptoms and enhance treatment of ulcerative colitis in clinical trials. Such properties are also found in selected strains of dairy starters such as Propionibacterium freudenreichii and Lactobacillus delbrueckii (Ld). We thus investigated the possibility to develop a fermented dairy product, combining both starter and probiotic abilities of both lactic acid and propionic acid bacteria, designed to extend remissions in IBD patients. We developed a single-strain Ld-fermented milk and a two-strain P. freudenreichii and Ld-fermented experimental pressed cheese using strains previously selected for their anti-inflammatory properties. Consumption of these experimental fermented dairy products protected mice against trinitrobenzenesulfonic acid induced colitis, alleviating severity of symptoms, modulating local and systemic inflammation, as well as colonic oxidative stress and epithelial cell damages. As a control, the corresponding sterile dairy matrix failed to afford such protection. This work reveals the probiotic potential of this bacterial mixture, in the context of fermented dairy products. It opens new perspectives for the reverse engineering development of anti-inflammatory fermented foods designed for target populations with IBD, and has provided evidences leading to an ongoing pilot clinical study in ulcerative colitis patients. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Polyhydroxyalkanoate production potential of heterotrophic bacteria in activated sludge.

    PubMed

    Inoue, Daisuke; Suzuki, Yuta; Uchida, Takahiro; Morohoshi, Jota; Sei, Kazunari

    2016-01-01

    This study was conducted to evaluate the polyhydroxyalkanoate (PHA) production potential of cultivable heterotrophic bacteria in activated sludge by genotypic and phenotypic characterizations. A total of 114 bacterial strains were isolated from four activated sludge samples taken from a lab-scale sequencing batch reactor and three wastewater treatment processes of two municipal wastewater treatment plants. PCR detection of the phaC genes encoding class I and II PHA synthase revealed that 15% of the total isolates possessed phaC genes, all of which had the closest similarities to known phaC genes of α- and β-Proteobacteria and Actinobacteria. PHA production experiments under aerobic and nitrogen-limited conditions showed that 68% of the total isolates were capable of producing PHA from at least one of the six substrates used (acetate, propionate, lactate, butyrate, glucose and glycerol). Genotypic and phenotypic characterizations revealed that 75% of the activated sludge bacteria had PHA production potential. Our results also indicated that short-chain fatty acids would be the preferable substrates for PHA production by activated sludge bacteria, and that there might be a variety of unidentified phaC genes in activated sludge. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Digestibility by lambs offered alfalfa hay treated with a propionic acid hay preservative and baled at different concentrations of moisture

    USDA-ARS?s Scientific Manuscript database

    Eighteen crossbred wether lambs (76.1 ± 8.18 lb initial BW) were used for a 2 period digestion study to evaluate the effect of hay preservative concentration (0, 0.56, or 0.98% buffered propionic acid) and hay moisture concentration at baling (19.6, 23.8, or 27.4% moisture) on digestibility of alfal...

  15. Effects of a propionic acid-based preservative on storage characteristics, nutritive value, and energy content for alfalfa hays packaged in large, round bales

    USDA-ARS?s Scientific Manuscript database

    During 2009 and 2010, alfalfa (Medicago sativa L.) hays from two cuttings that were harvested from the same field site were used to evaluate the effects of a propionic acid-based preservative on the storage characteristics and nutritive value of hays stored as large, round bales. A total of 87 large...

  16. The effects of whey and soy proteins on growth performance, gastrointestinal digestion, and selected physiological responses in rats.

    PubMed

    Wróblewska, B; Juśkiewicz, J; Kroplewski, B; Jurgoński, A; Wasilewska, E; Złotkowska, D; Markiewicz, L

    2018-03-01

    The objective of this work was to identify the nutritional and physiological effects of commercial soy and whey protein preparations. Wistar rats were fed with soy (S), whey (W), or casein (C) preparations as the sole dietary protein source. The nitrogen balance, body composition, changes in caecal microbiota, mucosal and bacterial enzyme activities, and allergenic potential of the preparations were analysed. The whey diet elicited greater skeletal muscle anabolism than the soy diet. Rats from the S group had the lowest values of body weight, fat, and lean mass gain. Compared to casein, soy and whey preparations decreased the protein efficiency ratio, increased N in the urine, and triggered the reduction of ammonia levels in the caecum. Changes in β-glucuronidase and β-galactosidase activities in the small intestine, caecum, and colon between experimental groups were observed. Significant differences were noted in the total counts of anaerobic bacteria and sulphite reducing bacteria during soy and whey treatments. This probably affected the short chain fatty acid level in caecal digesta resulting in the lowest propionic acid and total putrefactive short chain fatty acid levels during S treatment. Generally, whey preparations are a good choice for rapid bodybuilding (skeletal muscles), whereas soy preparations are more helpful during mass reduction.

  17. Polydextrose enrichment of infant formula demonstrates prebiotic characteristics by altering intestinal microbiota, organic acid concentrations, and cytokine expression in suckling piglets.

    PubMed

    Herfel, Tina M; Jacobi, Sheila K; Lin, Xi; Fellner, Vivek; Walker, D Carey; Jouni, Zeina E; Odle, Jack

    2011-12-01

    Oligosaccharides, the 3rd-most abundant component in human milk, are virtually absent from infant formulas and from the cow milk on which most are based. In breast-fed infants, human milk oligosaccharides (HMO) act as both receptor analogs, interfering with pathogen adhesion, and as prebiotics, stimulating the growth of certain commensal bacteria (e.g. bifidobacteria) and supporting the innate immunity. To further align the functional properties of infant formula with those of human milk, polydextrose (PDX) is proposed as a substitute for HMO. To determine the prebiotic functionality of PDX, 1-d-old pigs were fed a cow milk-based formula supplemented with increasing concentrations of PDX (0, 1.7, 4.3, 8.5, or 17 g/L) for 18 d (n = 13). Additional reference groups included pigs sampled at d 0 and sow-reared pigs sampled at d 18 (n = 12). Ileal Lactobacilli CFU, but not Bifidobacteria, increased linearly with increasing PDX (P = 0.02). The propionic acid concentration in digesta linearly increased with the PDX level (P = 0.045) and lactic acid increased linearly by 5-fold with increasing PDX (P = 0.001). Accordingly, digesta pH decreased linearly (P < 0.05) as PDX increased, with a maximal reduction approaching 0.5 pH units in pigs fed 17 g/L. Expression of TNFα, IL-1β, and IL-8 showed a negative quadratic pattern in response to PDX supplementation, declining at intermediate concentrations and rebounding at higher concentrations of PDX. In summary, PDX enrichment of infant formula resulted in a prebiotic effect by increasing ileal lactobacilli and propionic and lactic acid concentrations and decreasing pH with associated alterations in ileal cytokine expression.

  18. [Synchronous extraction and determination of phenoxy acid herbicides in water by on-line monolithic solid phase microextraction-high performance liquid chromatography].

    PubMed

    Wang, Jiabin; Wu, Fangling; Zhao, Qi

    2015-08-01

    A C18 monolithic capillary column was utilized as the solid phase microextraction column to construct an in-tube SPME-HPLC system which was used to simultaneously extract and detect five phenoxy acid herbicides, including 2,4-dichlorophenoxyacetic acid (2,4-D), 2- (2-chloro)-phenoxy propionic acid (2,2-CPPA), 2-(3-chloro)-phenoxy propionic acid (2,3- CPPA), phenoxy propionic acid (PPA) and 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP). The operating parameters of the in-tube SPME-HPLC system, including the length of the monolithic column, the sampling flow rate, the sampling time, the elution flow rate and the elution time, had been investigated in detail. The optimized operating parameters of the in-tube SPME-HPLC system were as follow: the length of the monolithic column was 20 cm, the sampling flow rate was 0. 04 mL/min, sampling time was 13 min; the elution flow rate was 0.02 mL/min, elution time was 5 min. Under the optimized conditions, the detection limits of the five phenoxy acid herbicides were as follows: 9 µg/L for PPA, 4 µg/L for 2,2-CPPA, 4 µg/L for 2,3-CPPA, 5 µg/L for 2,4-D, 5 µg/L for 2,4-DP. Compared with the HPLC method with direct injection, the combined system showed a good enrichment factors to the analytes. The recoveries of the five phenoxy acid herbicides were between 79.0% and 98.0% (RSD ≤ 3.9%). This method was successfully used to detect the five phenoxy acid herbicides in water samples with satisfactory results.

  19. Evaluating the potential impact of proton carriers on syntrophic propionate oxidation

    NASA Astrophysics Data System (ADS)

    Juste-Poinapen, Natacha M. S.; Turner, Mark S.; Rabaey, Korneel; Virdis, Bernardino; Batstone, Damien J.

    2015-12-01

    Anaerobic propionic acid degradation relies on interspecies electron transfer (IET) between propionate oxidisers and electron acceptor microorganisms, via either molecular hydrogen, formate or direct transfers. We evaluated the possibility of stimulating direct IET, hence enhancing propionate oxidation, by increasing availability of proton carriers to decrease solution resistance and reduce pH gradients. Phosphate was used as a proton carrying anion, and chloride as control ion together with potassium as counter ion. Propionic acid consumption in anaerobic granules was assessed in a square factorial design with ratios (1:0, 2:1, 1:1, 1:2 and 0:1) of total phosphate (TP) to Cl-, at 1X, 10X, and 30X native conductivity (1.5 mS.cm-1). Maximum specific uptake rate, half saturation, and time delay were estimated using model-based analysis. Community profiles were analysed by fluorescent in situ hybridisation and 16S rRNA gene pyrosequencing. The strongest performance was at balanced (1:1) ratios at 10X conductivity where presumptive propionate oxidisers namely Syntrophobacter and Candidatus Cloacamonas were more abundant. There was a shift from Methanobacteriales at high phosphate, to Methanosaeta at low TP:Cl ratios and low conductivity. A lack of response to TP, and low percentage of presumptive electroactive organisms suggested that DIET was not favoured under the current experimental conditions.

  20. Archaea and Bacteria Acclimate to High Total Ammonia in a Methanogenic Reactor Treating Swine Waste

    PubMed Central

    Parameswaran, Prathap; Rittmann, Bruce E.

    2016-01-01

    Inhibition by ammonium at concentrations above 1000 mgN/L is known to harm the methanogenesis phase of anaerobic digestion. We anaerobically digested swine waste and achieved steady state COD-removal efficiency of around 52% with no fatty-acid or H2 accumulation. As the anaerobic microbial community adapted to the gradual increase of total ammonia-N (NH3-N) from 890 ± 295 to 2040 ± 30 mg/L, the Bacterial and Archaeal communities became less diverse. Phylotypes most closely related to hydrogenotrophic Methanoculleus (36.4%) and Methanobrevibacter (11.6%), along with acetoclastic Methanosaeta (29.3%), became the most abundant Archaeal sequences during acclimation. This was accompanied by a sharp increase in the relative abundances of phylotypes most closely related to acetogens and fatty-acid producers (Clostridium, Coprococcus, and Sphaerochaeta) and syntrophic fatty-acid Bacteria (Syntrophomonas, Clostridium, Clostridiaceae species, and Cloacamonaceae species) that have metabolic capabilities for butyrate and propionate fermentation, as well as for reverse acetogenesis. Our results provide evidence countering a prevailing theory that acetoclastic methanogens are selectively inhibited when the total ammonia-N concentration is greater than ~1000 mgN/L. Instead, acetoclastic and hydrogenotrophic methanogens coexisted in the presence of total ammonia-N of ~2000 mgN/L by establishing syntrophic relationships with fatty-acid fermenters, as well as homoacetogens able to carry out forward and reverse acetogenesis. PMID:27725793

  1. Archaea and Bacteria Acclimate to High Total Ammonia in a Methanogenic Reactor Treating Swine Waste.

    PubMed

    Esquivel-Elizondo, Sofia; Parameswaran, Prathap; Delgado, Anca G; Maldonado, Juan; Rittmann, Bruce E; Krajmalnik-Brown, Rosa

    2016-01-01

    Inhibition by ammonium at concentrations above 1000 mgN/L is known to harm the methanogenesis phase of anaerobic digestion. We anaerobically digested swine waste and achieved steady state COD-removal efficiency of around 52% with no fatty-acid or H 2 accumulation. As the anaerobic microbial community adapted to the gradual increase of total ammonia-N (NH 3 -N) from 890 ± 295 to 2040 ± 30 mg/L, the Bacterial and Archaeal communities became less diverse. Phylotypes most closely related to hydrogenotrophic Methanoculleus (36.4%) and Methanobrevibacter (11.6%), along with acetoclastic Methanosaeta (29.3%), became the most abundant Archaeal sequences during acclimation. This was accompanied by a sharp increase in the relative abundances of phylotypes most closely related to acetogens and fatty-acid producers ( Clostridium , Coprococcus , and Sphaerochaeta ) and syntrophic fatty-acid Bacteria ( Syntrophomonas , Clostridium , Clostridiaceae species, and Cloacamonaceae species) that have metabolic capabilities for butyrate and propionate fermentation, as well as for reverse acetogenesis. Our results provide evidence countering a prevailing theory that acetoclastic methanogens are selectively inhibited when the total ammonia-N concentration is greater than ~1000 mgN/L. Instead, acetoclastic and hydrogenotrophic methanogens coexisted in the presence of total ammonia-N of ~2000 mgN/L by establishing syntrophic relationships with fatty-acid fermenters, as well as homoacetogens able to carry out forward and reverse acetogenesis.

  2. Continuous volatile fatty acid production from lignocellulosic biomass by a novel rumen-mimetic bioprocess.

    PubMed

    Agematu, Hitosi; Takahashi, Takehiko; Hamano, Yoshio

    2017-11-01

    Lignocellulosic biomass is an attractive source of biofuels and biochemicals, being abundant in various plant sources. However, processing this type of biomass requires hydrolysis of cellulose. The proposed rumen-mimetic bioprocess consists of dry-pulverization of lignocellulosic biomass and pH-controlled continuous cultivation of ruminal bacteria using ammonium as a nitrogen source. In this study, ruminal bacteria were continuously cultivated for over 60 days and used to digest microcrystalline cellulose, rice straw, and Japanese cedar to produce volatile fatty acids (VFAs). The ruminal bacteria grew well in the chemically defined medium. The amounts of VFAs produced from 20 g of cellulose, rice straw, and Japanese cedar were 183 ± 29.7, 69.6 ± 12.2, and 21.8 ± 12.9 mmol, respectively. Each digestion completed within 24 h. The carbon yield was 60.6% when 180 mmol of VFAs was produced from 20 g of cellulose. During the cultivation, the bacteria were observed to form flocs that enfolded the feed particles. These flocs likely contain all of the bacterial species necessary to convert lignocellulosic biomass to VFAs and microbial protein symbiotically. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rDNA fragments revealed that the bacterial community was relatively stable after 1 week in cultivation, though it was different from the original community structure. Furthermore, sequence analysis of the DGGE bands indicates that the microbial community includes a cellulolytic bacterium, a bacterium acting synergistically with cellulolytic bacteria, and a propionate-producing bacterium, as well as other anaerobic bacteria. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Growth and survival kinetics of Yersinia enterocolitica IP 383 0:9 as affected by equimolar concentrations of undissociated short-chain organic acids.

    PubMed

    el-Ziney, M G; De Meyer, H; Debevere, J M

    1997-03-03

    The influence of different organic acids (lactic, acetic, formic and propionic acids) at equimolar concentrations of undissociated acid with pH range of 3.9, 5.8, on the aerobic and anaerobic growth and survival kinetics of the virulent strain of Y. enterocolitica IP 383 0:9, was determined in tryptone soy broth at 4 degrees C. Growth and survival data were analyzed and fitted by a modification of the Whiting and Cygnarowicz-Provost model, using the Minpack software library. Initial generation times, initial specific growth rates, lag time and dead rate were subsequently calculated from the model parameters. The results demonstrate that the inhibitory effects of the acids were divided into two categories dependent upon pH. At high pH (5.8) the order of inhibition was formic acid > acetic acid > propionic acid > lactic acid, whereas at lower pH it became formic acid > lactic acid > acetic acid > propionic acid. The inhibitory effect of lactic acid is enhanced under anaerobic condition. Nevertheless, when the organism was cultured anaerobically, it was shown to be more tolerant to formic and acetic acids. Moreover, these variables (type of organic acid, pH and atmosphere) did not lead to the loss of the virulence plasmid in growing and surviving cells. The mechanism of inhibitory effect for each of the acids are also discussed.

  4. Bacterial production of short-chain organic acids and trehalose from levulinic acid: a potential cellulose-derived building block as a feedstock for microbial production.

    PubMed

    Habe, Hiroshi; Sato, Shun; Morita, Tomotake; Fukuoka, Tokuma; Kirimura, Kohtaro; Kitamoto, Dai

    2015-02-01

    Levulinic acid (LA) is a platform chemical derived from cellulosic biomass, and the expansion of LA utilization as a feedstock is important for production of a wide variety of chemicals. To investigate the potential of LA as a substrate for microbial conversion to chemicals, we isolated and identified LA-utilizing bacteria. Among the six isolated strains, Pseudomonas sp. LA18T and Rhodococcus hoagie LA6W degraded up to 70 g/L LA in a high-cell-density system. The maximal accumulation of acetic acid by strain LA18T and propionic acid by strain LA6W was 13.6 g/L and 9.1 g/L, respectively, after a 4-day incubation. Another isolate, Burkholderia stabilis LA20W, produced trehalose extracellularly in the presence of 40 g/L LA to approximately 2 g/L. These abilities to produce useful compounds supported the potential of microbial LA conversion for future development and cellulosic biomass utilization. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Evaluating the potential impact of proton carriers on syntrophic propionate oxidation

    PubMed Central

    Juste-Poinapen, Natacha M. S.; Turner, Mark S.; Rabaey, Korneel; Virdis, Bernardino; Batstone, Damien J.

    2015-01-01

    Anaerobic propionic acid degradation relies on interspecies electron transfer (IET) between propionate oxidisers and electron acceptor microorganisms, via either molecular hydrogen, formate or direct transfers. We evaluated the possibility of stimulating direct IET, hence enhancing propionate oxidation, by increasing availability of proton carriers to decrease solution resistance and reduce pH gradients. Phosphate was used as a proton carrying anion, and chloride as control ion together with potassium as counter ion. Propionic acid consumption in anaerobic granules was assessed in a square factorial design with ratios (1:0, 2:1, 1:1, 1:2 and 0:1) of total phosphate (TP) to Cl−, at 1X, 10X, and 30X native conductivity (1.5 mS.cm−1). Maximum specific uptake rate, half saturation, and time delay were estimated using model-based analysis. Community profiles were analysed by fluorescent in situ hybridisation and 16S rRNA gene pyrosequencing. The strongest performance was at balanced (1:1) ratios at 10X conductivity where presumptive propionate oxidisers namely Syntrophobacter and Candidatus Cloacamonas were more abundant. There was a shift from Methanobacteriales at high phosphate, to Methanosaeta at low TP:Cl ratios and low conductivity. A lack of response to TP, and low percentage of presumptive electroactive organisms suggested that DIET was not favoured under the current experimental conditions. PMID:26670292

  6. Viability, Acid and Bile Tolerance of Spray Dried Probiotic Bacteria and Some Commercial Probiotic Supplement Products Kept at Room Temperature.

    PubMed

    Dianawati, Dianawati; Mishra, Vijay; Shah, Nagendra P

    2016-06-01

    Production of probiotic food supplements that are shelf-stable at room temperature has been developed for consumer's convenience, but information on the stability in acid and bile environment is still scarce. Viability and acid and bile tolerance of microencapsulated Bifidobacterium spp. and Lactobacillus acidophilus and 4 commercial probiotic supplements were evaluated. Bifidobacterium and L. acidophilus were encapsulated with casein-based emulsion using spray drying. Water activity (aw ) of the microspheres containing Bifidobacterium or L. acidophilus (SD GM product) was adjusted to 0.07 followed by storage at 25 °C for 10 wk. Encapsulated Bifidobacterium spp. and Lactobacillus acidophilus and 4 commercial probiotic supplement products (AL, GH, RE, and BM) were tested. Since commercial probiotic products contained mixed bacteria, selective media MRS-LP (containing L-cysteine and Na-propionate) and MRS-clindamycin agar were used to grow Bifidobacterium spp. or L. acidophilus, respectively, and to inhibit the growth of other strains. The results showed that aw had a strong negative correlation with the viability of dehydrated probiotics of the 6 products. Viable counts of Bifidobacterium spp. and L. acidophilus of SD GM, AL, and GH were between 8.3 and 9.2 log CFU/g, whereas that of BM and RE were between 6.7 and 7.3 log CFU/g. Bifidobacterium in SD GM, in AL, and in GH products and L. acidophilus in SD GM, in AL, and in BM products demonstrated high tolerance to acid. Most of dehydrated probiotic bacteria were able to survive in bile environment except L. acidophilus in RE product. Exposure to gastric juice influenced bacterial survivability in subsequent bile environment. © 2016 Institute of Food Technologists®

  7. Short-term effect of acetate and ethanol on methane formation in biogas sludge.

    PubMed

    Refai, Sarah; Wassmann, Kati; Deppenmeier, Uwe

    2014-08-01

    Biochemical processes in biogas plants are still not fully understood. Especially, the identification of possible bottlenecks in the complex fermentation processes during biogas production might provide potential to increase the performance of biogas plants. To shed light on the question which group of organism constitutes the limiting factor in the anaerobic breakdown of organic material, biogas sludge from different mesophilic biogas plants was examined under various conditions. Therefore, biogas sludge was incubated and analyzed in anaerobic serum flasks under an atmosphere of N2/CO2. The batch reactors mirrored the conditions and the performance of the full-scale biogas plants and were suitable test systems for a period of 24 h. Methane production rates were compared after supplementation with substrates for syntrophic bacteria, such as butyrate, propionate, or ethanol, as well as with acetate and H2+CO2 as substrates for methanogenic archaea. Methane formation rates increased significantly by 35 to 126 % when sludge from different biogas plants was supplemented with acetate or ethanol. The stability of important process parameters such as concentration of volatile fatty acids and pH indicate that ethanol and acetate increase biogas formation without affecting normally occurring fermentation processes. In contrast to ethanol or acetate, other fermentation products such as propionate, butyrate, or H2 did not result in increased methane formation rates. These results provide evidence that aceticlastic methanogenesis and ethanol-oxidizing syntrophic bacteria are not the limiting factor during biogas formation, respectively, and that biogas plant optimization is possible with special focus on methanogenesis from acetate.

  8. Papaya (Carica papaya) leaf methanolic extract modulates in vitro rumen methanogenesis and rumen biohydrogenation.

    PubMed

    Jafari, Saeid; Goh, Yong M; Rajion, Mohamed A; Jahromi, Mohammad F; Ahmad, Yusof H; Ebrahimi, Mahdi

    2017-02-01

    Papaya leaf methanolic extract (PLE) at concentrations of 0 (CON), 5 (LLE), 10 (MLE) and 15 (HLE) mg/250 mg dry matter (DM) with 30 mL buffered rumen fluid were incubated for 24 h to identify its effect on in vitro ruminal methanogenesis and ruminal biohydrogenation (BH). Total gas production was not affected (P > 0.05) by addition of PLE compared to the CON at 24 h of incubation. Methane (CH 4 ) production (mL/250 mg DM) decreased (P < 0.05) with increasing levels of PLE. Acetate to propionate ratio was lower (P <0.05) in MLE (2.02) and HLE (1.93) compared to the CON (2.28). Supplementation of the diet with PLE significantly (P <0.05) decreased the rate of BH of C18:1n-9 (oleic acid; OA), C18:2n-6 (linoleic acid; LA), C18:3n-3 (linolenic acid; LNA) and C18 polyunsaturated fatty acids (PUFA) compared to CON after 24 h incubation, which resulted in higher concentrations of BH intermediates such as C18:1 t11 (vaccenic acid; VA), c9t11 conjugated LA (CLA) (rumenic acid; RA) and t10c12 CLA. Real-time PCR analysis indicated that the total bacteria, total protozoa, Butyrivibrio fibrisolvens and methanogen population in HLE decreased (P <0.05) compared to CON, but the total bacteria and B. fibrisolvens population were higher (P < 0.05) in CON compared to the PLE treatment groups. © 2016 Japanese Society of Animal Science.

  9. Anaerobic digestion of municipal solid waste composed of food waste, wastepaper, and plastic in a single-stage system: performance and microbial community structure characterization.

    PubMed

    Wan, Shungang; Sun, Lei; Douieb, Yaniv; Sun, Jian; Luo, Wensui

    2013-10-01

    The performance of municipal organic solid waste anaerobic digestion was investigated using a single-stage bioreactor, and the microbial community structures were characterized during the digestion. The results showed that the biogas and methane production rates were 592.4 and 370.1L/kg with volatile solid added at the ratio of 2:1:1 for food waste, wastepaper, and plastic based on dry weight. The methane volume concentration fluctuated between 44.3% and 75.4% at steady stage. Acetic acid, propionic acid, and butyric acid were the major volatile fatty acids produced during the digestion process. The anaerobic process was not inhibited by the accumulation of ammonia and free ammonia. The bacterial community was found to consist of at least 21 bands of bacteria and 12 bands of archaea at the steady state. All of the results indicated that the mixture of food waste, wastepaper, and plastic could be efficiently co-digested using the anaerobic digestion system. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Isolation and characterisation of obligately anaerobic, lipolytic bacteria from the rumen of red deer.

    PubMed

    Jarvis, G N; Strömpl, C; Moore, E R; Thiele, J H

    1998-03-01

    Two Gram-positive, obligately anaerobic, lipolytic bacteria, isolates LIP4 and LIP5, were obtained from the rumen contents of juvenile red deer. These mesophilic bacterial strains were capable of hydrolysing the neutral lipids, tallow, tripalmitin and oliver oil, into their constituent free long-chain fatty acid and glycerol moieties. The latter compound was dissimilated by both isolates, with isolate LIP4 producing propionate as the predominant product, while isolate LIP5 produced acetate, ethanol and succinate. The lactate-utilising isolate LIP4 grew on a limited range of saccharide substrates including glucose, fructose and ribose, and exhibited an unusual cell wall structure and morphology. The isolate LIP5 grew upon a wider range of saccharides, but was unable to use lactate as a substrate. Based upon phenotypic and 16S rRNA gene sequence analyses, isolate LIP4 clusters with species in the genus Propionibacterium, while isolate LIP5 is a member of clostridial cluster XIVa.

  11. Fiber-utilizing capacity varies in Prevotella- versus Bacteroides-dominated gut microbiota.

    PubMed

    Chen, Tingting; Long, Wenmin; Zhang, Chenhong; Liu, Shuang; Zhao, Liping; Hamaker, Bruce R

    2017-06-01

    The gut microbiota of individuals are dominated by different fiber-utilizing bacteria, which ferment dietary fiber into short chain fatty acids (SCFAs) known to be important for human health. Here, we show that the dominance of Prevotella versus Bacteroides in fecal innocula, identified into two different enterotypes, differentially impacts in vitro fermentation profiles of SCFAs from fibers with different chemical structures. In a microbiome of the Prevotella enterotype, fructooligosaccharides, and sorghum and corn arabinoxylans significantly promoted one single Prevotella OTU with equally high production of total SCFAs with propionate as the major product. Conversely, in the Bacteroides-dominated microbiota, the three fibers enriched different OTUs leading to different levels and ratios of SCFAs. This is the first report showing how individual differences in two enterotypes cause distinctly different responses to dietary fiber. Microbiota dominated by different fiber-utilizing bacteria may impact host health by way of producing different amounts and profiles of SCFAs from the same carbohydrate substrates.

  12. Co-digestion of wheat and rye bread suspensions with source-sorted municipal biowaste

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

    Li, Chaoran, E-mail: Chaoran.Li3@kit.edu; Mörtelmaier, Christoph, E-mail: Christoph.Moertelmaier@kit.edu; Winter, Josef, E-mail: Josef.Winter@kit.edu

    Graphical abstract: Volatile fatty acid spectra of acidified WBS, RBS or FBS differ, but methanogenesis is similar. Display Omitted - Highlights: • Biogas improvement by co-digestion of wheat and rye bread. • Increased population density at high organic loading rates. • Less Pelotomaculum but increased numbers of Syntrophobacter and Smithella found in rye bread reactor. • Replacement of Methanosarcinales by acetate-oxidizers in rye bread co-digestion. • Increasing proportion of Methanomicrobiales in biowaste + rye bread reactor. - Abstract: Acidification of wheat bread (WBS), rye bread (RBS) and fresh biowaste suspensions (FBS), leading to lactate+acetate, lactate+acetate+n-buyrate, and acetate+propionate+n-butyrate, respectively, and biogasmore » production as well as population dynamics were investigated. Co-fermentation of FBS (14 kg m{sup −3} d{sup −1} organic loading rate (OLR)) with WBS or RBS was stable up to an OLR of 22 kg m{sup −3} d{sup −1} and resulted in up to 3 times as much biogas. During co-fermentation at more than 20 kg m{sup −3} d{sup −1} OLR the total population increased more than 2-fold, but the originally low share of propionate-oxidizing bacteria significantly decreased. The proportion of methanogens also decreased. Whereas the proportion of Methanosarcinales to Methanomicrobiales in biowaste and biowaste+WBS remained constant, Methanosarcinales and in particular Methanosaeta spec. in the biowaste+RBS assay almost completely disappeared. Methanomicrobiales increased instead, indicating propionate oxidation via acetate cleavage to CO{sub 2} and hydrogen.« less

  13. Stabilizing effect of propionic acid derivative of anthraquinone--polyamine conjugate incorporated into α-β chimeric oligonucleotides on the alternate-stranded triple helix.

    PubMed

    Moriguchi, Tomohisa; Azam, A T M Zafrul; Shinozuka, Kazuo

    2011-06-15

    Two types of anthraquinone conjugates were synthesized as non-nucleosidic oligonucleotide components. These include an anthraquinone derivative conjugated with 2,2-bis(hydroxymethyl)propionic acid and an anthraquinone--polyamine derivative conjugated with 2,2-bis(hydroxymethyl)propionic acid. The conjugates were successfully incorporated into the "linking-region" of the α-β chimeric oligonucleotides via phosphoramidite method as non-nucleosidic backbone units. The resultant novel α-β chimeric oligonucleotides possessed two diastereomers that were generated by the introduction of the anthraquinone conjugate with a stereogenic carbon atom. The isomers were successfully separated by a reversed-phase HPLC. UV-melting experiments revealed that both stereoisomers formed a substantially stable alternate-strand triple helix, irrespective of the stereochemistry of the incorporated non-nucleosidic backbone unit. However, the enhancing effect on thermal stability depended on the length of the alkyl linker connecting anthraquinone moiety and the propionic acid moiety. The sequence discrimination ability of the chimeric oligonucleotides toward mismatch target duplex was also examined. The T(m) values of the triplexes containing the mismatch target were substantially lower than the T(m) values of those containing the full-match target. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) required for the dissociation of the triplexes into the third strand and target duplex were also measured.

  14. [Studies on anaerobic infection in oro-maxillary region--rapid diagnosis by gas-liquid chromatography and antibiotic susceptibilities of anaerobic bacteria].

    PubMed

    Tanaka, J I

    1989-08-01

    Subject material for this study was pus collected from patients with purulent inflammation in the oro-maxillary region. Direct gas-liquid chromatography (GLC) analysis was made, bacterial isolation and identification were carried out, and comparisons were made with results from GLC analysis and anaerobic isolates in a PYG medium. In addition, antibiotic susceptibilities of anaerobic bacteria were examined. Results 1. Anaerobic bacteria were isolated from 85 of 100 cases of obstructive abscesses. Of the 85, 49 were cases of mixed infection involving both anaerobic and aerobic bacteria; and 64 cases were involved with more than 2 species of anaerobic bacteria. Of the 184 strains of anaerobic isolates, 53 were Bacteroides sp. and 51 were Peptostreptococcus sp. The 2 groups accounted for more than half of the isolates. 2. Group A, in which no VFA was detected, accounted for 17 out of 100 cases. Group B, in which acetic acid was detected, accounted for 20 cases; and Group C, in which butyric acid was detected, accounted for 20 cases; and Group D, in which iso-valeric acid was detected, accounted for 8 cases. Direct GLC analysis revealed iso-caproic and caproic acids in the 35 cases constituting Group E. 3. Whereas the percentage of anaerobic bacteria was 64.7% in Group A and 60% in Group B, significantly higher percentages were noted in Group C (95%), Group D (100%) and Group E (100%). The following species were isolated as major member in the groups; Group A--Streptococcus intermedius, Group B--Peptostreptococcus micros, Group C--Fusobacterium nucleatum, Group D--Bacteroides gingivalis, and Group E--Peptostreptococcus anaerobius. 4. In all cases, the sum of VFA produced in the PYG medium by anaerobic isolates was classified into Group A' to E'. Ratios of agreement between VFA as revealed by direct GLC and VFA as revealed by PYG.GLC were as follows: Group A-A'; 47.1%, Group B-B' and C-C'; 45%, Group D-D'; 87.5%, and Group E-E'; 62.9%. 5. In Group B, no propionic acid was detected. The 2 cases in which acetic acid occurred in a concentration greater than 14 x 10(-4) meq/ml belonged to Group B'. In Group C, no isobutyric acid was detected; and the 5 cases in which butyric acid was detected in a concentration of more than 7 x 10(-4) meq/ml belonged to Group C'. Varelic acid was not detected in Group D; and 7 out of the 8 cases in which iso-valeric acid, irrespective of concentration, was detected belonged to Group D'.(ABSTRACT TRUNCATED AT 400 WORDS)

  15. Denitrifying sulfur conversion-associated EBPR: Effects of temperature and carbon source on anaerobic metabolism and performance.

    PubMed

    Guo, Gang; Wu, Di; Ekama, George A; Hao, Tianwei; Mackey, Hamish Robert; Chen, Guanghao

    2018-04-16

    The recently developed Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) process has demonstrated simultaneous removal of organics, nitrogen and phosphorus with minimal sludge production in the treatment of saline/brackish wastewater. Its performance, however, is sensitive to operating and environmental conditions. In this study, the effects of temperature (20, 25, 30 and 35 °C) and the ratio of influent acetate to propionate (100-0, 75-25, 50-50, 25-75 and 0-100%) on anaerobic metabolism were investigated, and their optimal values/controls for performance optimization were identified. A mature DS-EBPR sludge enriched with approximately 30% sulfate-reducing bacteria (SRB) and 33% sulfide-oxidizing bacteria (SOB) was used in this study. The anaerobic stoichiometry of this process was insensitive to temperature or changes in the carbon source. However, an increase in temperature from 20 to 35 °C accelerated the kinetic reactions of the functional bacteria (i.e. SRB and SOB) and raised the energy requirement for their anaerobic maintenance, while a moderate temperature (25-30 °C) resulted in better P removal (≥93%, 18.6 mg P/L removal from total 20 mg P/L in the influent) with a maximum sulfur conversion of approximately 16 mg S/L. These results indicate that the functional bacteria are likely to be mesophilic. When a mixed carbon source (75-25 and 50-50% acetate to propionate ratios) was supplied, DS-EBPR achieved a stable P removal (≥89%, 17.8 mg P/L for 400 mg COD/L in the influent) with sulfur conversions at around 23 mg S/L, suggesting the functional bacteria could effectively adapt to changes in acetate or propionate as the carbon source. The optimal temperatures or carbon source conditions maximized the functional bacteria competition against glycogen-accumulating organisms by favoring their activity and synergy. Therefore, the DS-EBPR process can be optimized by setting the temperature in the appropriate range (25-30 °C) and/or manipulating influent carbon sources. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Anaplerotic therapy in propionic acidemia.

    PubMed

    Longo, Nicola; Price, Leisa B; Gappmaier, Eduard; Cantor, Nancy L; Ernst, Sharon L; Bailey, Carrie; Pasquali, Marzia

    2017-09-01

    Propionic acidemia is a rare metabolic disorder caused by a deficiency of propionyl- CoA carboxylase, the enzyme converting propionyl-CoA to methylmalonyl-CoA that subsequently enters the citric acid cycle as succinyl-CoA. Patients with propionic acidemia cannot metabolize propionic acid, which combines with oxaloacetate to form methylcitric acid. This, with the defective supply of succinyl-CoA, may lead to a deficiency in citric acid cycle intermediates. The objective of this study was to determine whether supplements with glutamine (400mg/kg per day), citrate (7.5mEq/kg per day), or ornithine α-ketoglutarate (400mg/kg per day) (anaplerotic agents that could fill up the citric acid cycle) would affect plasma levels of glutamine and ammonia, the urinary excretion of Krebs cycle intermediates, and the clinical outcome in 3 patients with propionic acidemia. Each supplement was administered daily for four weeks with a two week washout period between supplements. The supplement that produced the most favorable changes was supplemented for 30 weeks following the initial study period and then for a 2 year extension. The urinary excretion of the Krebs cycle intermediates, α-ketoglutarate, succinate, and fumarate increased significantly compared to baseline during citrate supplementation, but not with the other two supplements. For this reason, citrate supplements were continued in the second part of the study. The urinary excretion of methylcitric acid and 3-hydroxypropionic acid did not change with any intervention. No significant changes in ammonia or glutamine levels were observed with any supplement. However, supplementation with any anaplerotic agents normalized the physiological buffering of ammonia by glutamate, with plasma glutamate and alanine levels significantly increasing, rather than decreasing with increasing ammonia levels. No significant side effects were observed with any therapy and safety labs (blood counts, chemistry and thyroid profile) remained unchanged. Motor and cognitive development was severely delayed before the trial and did not change significantly with therapy. Hospitalizations per year did not change during the trial period, but decreased significantly (p<0.05) in the 2years following the study (when citrate was continued) compared to the 2years before and during the study. These results indicate that citrate entered the Krebs cycle providing successful anaplerotic therapy by increasing levels of the downstream intermediates of the Krebs cycle: α-ketoglutarate, succinate and fumarate. Citrate supplements were safe and might have contributed to reduce hospitalizations in patients with propionic acidemia. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Enteric short-chain fatty acids: microbial messengers of metabolism, mitochondria, and mind: implications in autism spectrum disorders

    PubMed Central

    MacFabe, Derrick F.

    2015-01-01

    Clinical observations suggest that gut and dietary factors transiently worsen and, in some cases, appear to improve behavioral symptoms in a subset of persons with autism spectrum disorders (ASDs), but the reason for this is unclear. Emerging evidence suggests ASDs are a family of systemic disorders of altered immunity, metabolism, and gene expression. Pre- or perinatal infection, hospitalization, or early antibiotic exposure, which may alter gut microbiota, have been suggested as potential risk factors for ASD. Can a common environmental agent link these disparate findings? This review outlines basic science and clinical evidence that enteric short-chain fatty acids (SCFAs), present in diet and also produced by opportunistic gut bacteria following fermentation of dietary carbohydrates, may be environmental triggers in ASD. Of note, propionic acid, a major SCFA produced by ASD-associated gastrointestinal bacteria (clostridia, bacteroides, desulfovibrio) and also a common food preservative, can produce reversible behavioral, electrographic, neuroinflammatory, metabolic, and epigenetic changes closely resembling those found in ASD when administered to rodents. Major effects of these SCFAs may be through the alteration of mitochondrial function via the citric acid cycle and carnitine metabolism, or the epigenetic modulation of ASD-associated genes, which may be useful clinical biomarkers. It discusses the hypothesis that ASDs are produced by pre- or post-natal alterations in intestinal microbiota in sensitive sub-populations, which may have major implications in ASD cause, diagnosis, prevention, and treatment. PMID:26031685

  18. Vertical gradients in carbon flow and methane production in a sulfate-rich oil sands tailings pond.

    PubMed

    Stasik, Sebastian; Wendt-Potthoff, Katrin

    2016-12-01

    Oil sands tailings ponds are primary storage basins for tailings produced during oil sands processing in Alberta (Canada). Due to microbial metabolism, methane production contributes to greenhouse gas emissions, but positively affects tailings densification, which is relevant for operational water re-use. Depending on the age and depth of tailings, the activity of sulfate-reducing bacteria (SRB) may control methanogenesis due to the competition for substrates. To assess the depth-related impact of sulfate reduction on CH 4 emissions, original tailings of two vicinal pond profiles were incubated in anoxic microcosms with/without molybdate as selective inhibitor of microbial sulfate reduction. Integrating methane production rates, considerable volumes of CH 4 emissions (∼5.37 million L d -1 ) may be effectively prevented by the activity of SRB in sulfidic tailings between 3.5 and 7.5 m. To infer metabolic potentials controlling methanogenic pathways, a set of relevant organic acids (acetate, formate, propionate, butyrate, lactate) was added to part of the microcosms. Generally, organic acid transformation shifted with depth, with highest rates (305-446 μmol L -1  d -1 ) measured in fresh tailings at 5.5-7.5 m. In all depths, a transient accumulation of acetate revealed its importance as key intermediate during organic matter decomposition. SRB dominated the transformation of acetate, butyrate and propionate, but were not essential for lactate and formate turnover. Acetate as methanogenic substrate was important only at 13.5 m. At 1-7.5 m, methanogenesis significantly increased in presence of organic acids, most likely due to the syntrophic oxidation of acetate to CO 2 by SRB and subsequent conversion to CH 4 . Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Metabolic network rewiring of propionate flux compensates vitamin B12 deficiency in C. elegans

    PubMed Central

    Watson, Emma; Olin-Sandoval, Viridiana; Hoy, Michael J; Li, Chi-Hua; Louisse, Timo; Yao, Victoria; Mori, Akihiro; Holdorf, Amy D; Troyanskaya, Olga G; Ralser, Markus; Walhout, Albertha JM

    2016-01-01

    Metabolic network rewiring is the rerouting of metabolism through the use of alternate enzymes to adjust pathway flux and accomplish specific anabolic or catabolic objectives. Here, we report the first characterization of two parallel pathways for the breakdown of the short chain fatty acid propionate in Caenorhabditis elegans. Using genetic interaction mapping, gene co-expression analysis, pathway intermediate quantification and carbon tracing, we uncover a vitamin B12-independent propionate breakdown shunt that is transcriptionally activated on vitamin B12 deficient diets, or under genetic conditions mimicking the human diseases propionic- and methylmalonic acidemia, in which the canonical B12-dependent propionate breakdown pathway is blocked. Our study presents the first example of transcriptional vitamin-directed metabolic network rewiring to promote survival under vitamin deficiency. The ability to reroute propionate breakdown according to B12 availability may provide C. elegans with metabolic plasticity and thus a selective advantage on different diets in the wild. DOI: http://dx.doi.org/10.7554/eLife.17670.001 PMID:27383050

  20. Metabolism of propionate by sheep liver. Interrelations of propionate and glutamate in aged mitochondria

    PubMed Central

    Smith, R. M.; Osborne-White, W. S.; Russell, G. R.

    1965-01-01

    1. Low concentrations of l-glutamate were slowly and quantitatively converted into aspartate by aged sheep-liver mitochondria with the loss of C-1 of the glutamate. 2. When propionate was present in addition the rate of conversion of glutamate into aspartate was increased slightly, and the presence of glutamate caused a marked stimulation in the rate at which propionate was metabolized. 3. The stimulatory effect of `sparker' amounts of l-glutamate on propionate metabolism was matched by the effects of α-oxoglutarate, pyruvate, citrate and isocitrate, but not by succinate, fumarate, malate or oxaloacetate. Succinate was stimulatory at higher concentrations, whereas oxaloacetate was inhibitory. 4. When propionate was incubated with l-[1-14C]glutamate in the presence of a large excess of unlabelled carbon dioxide, some labelling of dicarboxylic acids and aspartate occurred, but this was much less than would have been expected from an obligatory transcarboxylation from C-1 of α-oxoglutarate to propionyl-CoA. 5. Possible mechanisms of these effects are discussed. PMID:14340093

  1. The control of fatty acid metabolism in liver cells from fed and starved sheep.

    PubMed Central

    Lomax, M A; Donaldson, I A; Pogson, C I

    1983-01-01

    Isolated liver cells prepared from starved sheep converted palmitate into ketone bodies at twice the rate seen with cells from fed animals. Carnitine stimulated palmitate oxidation only in liver cells from fed sheep, and completely abolished the difference between fed and starved animals in palmitate oxidation. The rates of palmitate oxidation to CO2 and of octanoate oxidation to ketone bodies and CO2 were not affected by starvation or carnitine. Neither starvation nor carnitine altered the ratio of 3-hydroxybutyrate to acetoacetate or the rate of esterification of [1-14C]palmitate. Propionate, lactate, pyruvate and fructose inhibited ketogenesis from palmitate in cells from fed sheep. Starvation or the addition of carnitine decreased the antiketogenic effectiveness of gluconeogenic precursors. Propionate was the most potent inhibitor of ketogenesis, 0.8 mM producing 50% inhibition. Propionate, lactate, fructose and glycerol increased palmitate esterification under all conditions examined. Lactate, pyruvate and fructose stimulated oxidation of palmitate and octanoate to CO2. Starvation and the addition of gluconeogenic precursors stimulated apparent palmitate utilization by cells. Propionate, lactate and pyruvate decreased cellular long-chain acylcarnitine concentrations. Propionate decreased cell contents of CoA and acyl-CoA. It is suggested that propionate may control hepatic ketogenesis by acting at some point in the beta-oxidation sequence. The results are discussed in relation to the differences in the regulation of hepatic fatty acid metabolism between sheep and rats. PMID:6615480

  2. Value of acid metabolic products in identification of certain corynebacteria.

    PubMed Central

    Reddy, C A; Kao, M

    1978-01-01

    Acid metabolic products of 23 strains of human and animal pathogenic corynebacteria, representing eight different species, were determined by gas chromatography. The results showed that the species examined were metabolically heterogeneous and could be presumptively identified based on the acid products produced. Corynebacterium equi did not produce any acids; C. renale produced lactate; and C. pyogenes produced major amounts of lactate, variable amounts of acetate, and minor amounts of succinate and pyruvate. C. kutscheri produced propionate and lactate as major products and pyruvate and oxalacetate as minor products. C. diphtheriae and C. pseudotuberculosis produced major amounts of propionate, acetate, and formate. In addition, C. pseudotuberculosis produced major amounts of pyruvate and minor amounts of succinate, lactate, and oxalacetate, whereas C. diphtheriae strains produced minor but variable amounts of lactate, succinate, fumarate, pyruvate, and oxalacetate. C. bovis produced aicd products similar to those of C. pyogenes but was readily distinguishable from the latter by the lack of hemolysis on blood agar, colony morphology, catalase reaction, and biochemicals. C. suis characteristically produced major amounts of ethanol, acetate, and formate and minor amounts of lactate and succinate but no propionate. PMID:96126

  3. Methylcitrate cycle defines the bactericidal essentiality of isocitrate lyase for survival of Mycobacterium tuberculosis on fatty acids

    PubMed Central

    Eoh, Hyungjin; Rhee, Kyu Y.

    2014-01-01

    Few mutations attenuate Mycobacterium tuberculosis (Mtb) more profoundly than deletion of its isocitrate lyases (ICLs). However, the basis for this attenuation remains incompletely defined. Mtb’s ICLs are catalytically bifunctional isocitrate and methylisocitrate lyases required for growth on even and odd chain fatty acids. Here, we report that Mtb’s ICLs are essential for survival on both acetate and propionate because of its methylisocitrate lyase (MCL) activity. Lack of MCL activity converts Mtb’s methylcitrate cycle into a “dead end” pathway that sequesters tricarboxylic acid (TCA) cycle intermediates into methylcitrate cycle intermediates, depletes gluconeogenic precursors, and results in defects of membrane potential and intrabacterial pH. Activation of an alternative vitamin B12-dependent pathway of propionate metabolism led to selective corrections of TCA cycle activity, membrane potential, and intrabacterial pH that specifically restored survival, but not growth, of ICL-deficient Mtb metabolizing acetate or propionate. These results thus resolve the biochemical basis of essentiality for Mtb’s ICLs and survival on fatty acids. PMID:24639517

  4. Isolation and Characterization of Thermophilic Bacilli Degrading Cinnamic, 4-Coumaric, and Ferulic Acids

    PubMed Central

    Peng, Xue; Misawa, Norihiko; Harayama, Shigeaki

    2003-01-01

    Thirty-four thermophilic Bacillus sp. strains were isolated from decayed wood bark and a hot spring water sample based on their ability to degrade vanillic acid under thermophilic conditions. It was found that these bacteria were able to degrade a wide range of aromatic acids such as cinnamic, 4-coumaric, 3-phenylpropionic, 3-(p-hydroxyphenyl)propionic, ferulic, benzoic, and 4-hydroxybenzoic acids. The metabolic pathways for the degradation of these aromatic acids at 60°C were examined by using one of the isolates, strain B1. Benzoic and 4-hydroxybenzoic acids were detected as breakdown products from cinnamic and 4-coumaric acids, respectively. The β-oxidative mechanism was proposed to be responsible for these conversions. The degradation of benzoic and 4-hydroxybenzoic acids was determined to proceed through catechol and gentisic acid, respectively, for their ring fission. It is likely that a non-β-oxidative mechanism is the case in the ferulic acid catabolism, which involved 4-hydroxy-3-methoxyphenyl-β-hydroxypropionic acid, vanillin, and vanillic acid as the intermediates. Other strains examined, which are V0, D1, E1, G2, ZI3, and H4, were found to have the same pathways as those of strain B1, except that strains V0, D1, and H4 had the ability to transform 3-hydroxybenzoic acid to gentisic acid, which strain B1 could not do. PMID:12620824

  5. Kinetics and methane gas yields of selected C1 to C5 organic acids in anaerobic digestion.

    PubMed

    Yang, Yu; Chen, Qian; Guo, Jialiang; Hu, Zhiqiang

    2015-12-15

    Volatile fatty acids (VFAs) and other short-chain organic acids such as lactic and pyruvic acids are intermediates in anaerobic organic degradation. In this study, anaerobic degradation of seven organic acids in salt form was investigated, including formate (C1), acetate (C2), propionate (C3), pyruvate (C3), lactate (C3), butyrate (C4), and valerate (C5). Microbial growth kinetics on these organic acids were determined individually at 37 °C through batch anaerobic digestion tests by varying substrate concentrations from 250 to 4000 mg COD/L. The cumulative methane generation volume was determined real-time by respirometry coupled with gas chromatographic analysis while methane yield and related kinetics were calculated. The methane gas yields (fe, mg CH4 COD/mg substrate COD) from anaerobic degradation of formate, acetate, propionate, pyruvate, lactate, butyrate, and valerate were 0.44 ± 0.27, 0.58 ± 0.05, 0.53 ± 0.18, 0.24 ± 0.05, 0.17 ± 0.05, 0.43 ± 0.15, 0.49 ± 0.11, respectively. Anaerobic degradation of formate showed self-substrate inhibition at the concentrations above 3250 mg COD/L. Acetate, propionate, pyruvate, butyrate, lactate, and valerate did not inhibit methane production at the highest concentrations tested (i.e., 4000 mg COD/L). Microbes growing on acetate had the highest overall specific growth rate (0.30 d(-1)) in methane production. For comparison, the specific microbial growth rates on formate, propionate, pyruvate, butyrate, lactate, and valerate for methane production were 0.10, 0.06, 0.08, 0.07, 0.05, 0.15 d(-1), respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The interaction of propionic and butyric acids with ice and HNO₃-doped ice surfaces at 195-212 K.

    PubMed

    Romanias, Manolis N; Papadimitriou, Vassileios C; Papagiannakopoulos, Panos

    2014-12-04

    The interaction of propionic and butyric acids on ice and HNO3-doped ice were studied between 195 and 212 K and low concentrations, using a Knudsen flow reactor coupled with a quadrupole mass spectrometer. The initial uptake coefficients (γ0) of propionic and butyric acids on ice as a function of temperature are given by the expressions: γ0(T) = (7.30 ± 1.0) × 10(-10) exp[(3216 ± 478)/T] and γ0(T) = (6.36 ± 0.76) × 10(-11) exp[(3810 ± 434)/T], respectively; the quoted error limits are at 95% level of confidence. Similarly, γ0 of propionic acid on 1.96 wt % (A) and 7.69 wt % (B) HNO3-doped ice with temperature are given as γ(0,A)(T) = (2.89 ± 0.26) × 10(-8) exp[(2517 ± 266)/T] and γ(0,B)(T) = (2.77 ± 0.29) × 10(-7) exp[(2126 ± 206)/T], respectively. The results show that γ0 of C1 to C4 n-carboxylic acids on ice increase with the alkyl-group length, due to lateral interactions between alkyl-groups that favor a more perpendicular orientation and well packing of H-bonded monomers on ice. The high uptakes (>10(15) molecules cm(-2)) and long recovery signals indicate efficient growth of random multilayers above the first monolayer driven by significant van der Waals interactions. The heterogeneous loss of both acids on ice and HNO3-doped ice particles in dense cirrus clouds is estimated to take a few minutes, signifying rapid local heterogeneous removal by dense cirrus clouds.

  7. Fermentation and microbial population dynamics during the ensiling of native grass and subsequent exposure to air.

    PubMed

    Zhang, Qing; Wu, Baiyila; Nishino, Naoki; Wang, Xianguo; Yu, Zhu

    2016-03-01

    To study the microbial population and fermentation dynamics of large needlegrass (LN) and Chinese leymus (CL) during ensiling and subsequent exposure to air, silages were sampled and analyzed using culture-based techniques and denaturing gradient gel electrophoresis (DGGE). A total of 112 lactic acid bacteria (LAB) strains were isolated and identified using the 16S rRNA sequencing method. Lactic acid was not detected in the first 20 days in LN silage and the pH decreased to 6.13 after 45 days of ensiling. The temperature of the LN silage increased after approximately 30 h of air exposure and the CL silage showed a slight temperature variation. Enterococcus spp. were mainly present in LN silage. The proportion of Lactobacillus brevis in CL silage increased after exposure to air. LN silage with a higher proportion of Enterococcus spp. and propionic acid concentration did not show higher fermentation quality or aerobic stability than CL silage, which had a higher concentration of acetic acid, butyric acid and increased proportion of L. brevis after exposure to air. © 2015 Japanese Society of Animal Science.

  8. Inhibition of Listeria monocytogenes by propionic acid-based ingredients in cured deli-style Turkey.

    PubMed

    Glass, Kathleen A; McDonnell, Lindsey M; Von Tayson, Roxanne; Wanless, Brandon; Badvela, Mani

    2013-12-01

    Listeria monocytogenes growth can be controlled on ready-to-eat meats through the incorporation of antimicrobial ingredients into the formulation or by postlethality kill steps. However, alternate approaches are needed to provide options that reduce sodium content but maintain protection against pathogen growth in meats after slicing. The objective of this study was to determine the inhibition of L. monocytogenes by propionic acid-based ingredients in high-moisture, cured turkey stored at 4 or 7°C. Six formulations of sliced, cured (120 ppm of NaNO2 ), deli-style turkey were tested, including control without antimicrobials, 3.2% lactate-diacetate blend (LD), 0.4% of a liquid propionate-benzoate-containing ingredient, or 0.3, 0.4, and 0.5% of a liquid propionate-containing ingredient. Products were inoculated with 5 log CFU L. monocytogenes per 100-g package (3 log CFU/ml rinsate), vacuum-sealed, and stored at 4 or 7°C for up to 12 weeks; and populations were enumerated by plating on modified Oxford agar. As expected, the control without antimicrobials supported rapid growth, with >2 log average per ml rinsate increase within 4 weeks of storage at 4°C, whereas growth was observed at 6 weeks for the LD treatment. For both replicate trials, all treatments that contained liquid propionate or propionate-benzoate limited L. monocytogenes growth to an increase of <1 log through 9 weeks storage at 4°C. Sporadic growth (>1-log increase) was observed in individual samples for all propionate-containing treatments at weeks 10, 11, and 12. As expected, L. monocytogenes grew more rapidly when products were stored at 7°C, but trends in relative inhibition were similar to those observed at 4°C. These results verify that propionate-based ingredients inhibit growth of L. monocytogenes on sliced, high-moisture, cured turkey and can be considered as an alternative to reduce sodium-based salts while maintaining food safety.

  9. Long-term competition between sulfate reducing and methanogenic bacteria in UASB reactors treating volatile fatty acids.

    PubMed

    Omil, F; Lens, P; Visser, A; Hulshoff Pol, L W; Lettinga, G

    1998-03-20

    The competition between acetate utilizing methane-producing bacteria (MB) and sulfate-reducing bacteria (SRB) was studied in mesophilic (30 degrees C) upflow anaerobic sludge bed (UASB) reactors (upward velocity 1 m h-1; pH 8) treating volatile fatty acids and sulfate. The UASB reactors treated a VFA mixture (with an acetate:propionate:butyrate ratio of 5:3:2 on COD basis) or acetate as the sole substrate at different COD:sulfate ratios. The outcome of the competition was evaluated in terms of conversion rates and specific methanogenic and sulfidogenic activities. The COD:sulfate ratio was a key factor in the partitioning of acetate utilization between MB and SRB. In excess of sulfate (COD:sulfate ratio lower than 0.67), SRB became predominant over MB after prolonged reactor operation: 250 and 400 days were required to increase the amount of acetate used by SRB from 50 to 90% in the reactor treating, respectively, the VFA mixture or acetate as the sole substrate. The competition for acetate was further studied by dynamic simulations using a mathematical model based on the Monod kinetic parameters of acetate utilizing SRB and MB. The simulations confirmed the long term nature of the competition between these acetotrophs. A high reactor pH (+/-8), a short solid retention time (<150 days), and the presence of a substantial SRB population in the inoculum may considerably reduce the time required for acetate-utilising SRB to outcompete MB. Copyright 1998 John Wiley & Sons, Inc.

  10. Growth inhibition of Cronobacter spp. strains in reconstituted powdered infant formula acidified with organic acids supported by natural stomach acidity.

    PubMed

    Zhu, S; Schnell, S; Fischer, M

    2013-09-01

    Cronobacter is associated with outbreaks of rare, but life-threatening cases of meningitis, necrotizing enterocolitis, and sepsis in newborns. This study was conducted to determine the effect of organic acids on growth of Cronobacter in laboratory medium and reconstituted powdered infant formula (PIF) as well as the bacteriostatic effect of slightly acidified infant formula when combined with neonatal gastric acidity. Inhibitory effect of seven organic acids on four acid sensitive Cronobacter strains was determined in laboratory medium with broth dilution method at pH 5.0, 5.5 and 6.0. Acetic, butyric and propionic acids were most inhibitive against Cronobacter in the laboratory medium. The killing effect of these three acids was partially buffered in reconstituted PIF. Under neonatal gastric acid condition of pH 5.0, the slightly acidified formula which did not exert inhibition effect solely reduced significantly the Cronobacter populations. A synergistic effect of formula moderately acidified with organic acid combined with the physiological infant gastric acid was visible in preventing the rapid growth of Cronobacter in neonatal stomach. The study contributed to a better understanding of the inhibitory effect of organic acids on Cronobacter growth in different matrixes and provided new ideas in terms of controlling bacteria colonization and translocation by acidified formula. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Effect of Applying Molasses and Propionic Acid on Fermentation Quality and Aerobic Stability of Total Mixed Ration Silage Prepared with Whole-plant Corn in Tibet

    PubMed Central

    Chen, Lei; Guo, Gang; Yuan, Xianjun; Shimojo, Masataka; Yu, Chengqun; Shao, Tao

    2014-01-01

    The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR) silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM) was ensiled with four different treatments: no additive (control), molasses (M), propionic acid (P), and molasses+propionic acid (PM), in laboratory silos (250 mL) and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN), and high lactic acid (LA) content and V-scores. M silage showed the highest (p<0.05) LA content and higher dry matter (DM) recovery than the control and P silages. P silage had lower (p<0.05) LA content than the control silage. During aerobic exposure, lactic acid contents decreased gradually in the control and M silages, while that of P and PM silages increased, and the peak values were observed after 9 d. M silage had similar yeast counts with the control silage (>105 cfu/g FM), however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (<105 cfu/g FM) (p<0.05) and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage. PMID:25049961

  12. Construction of an artificial symbiotic community using a Chlorella–symbiont association as a model

    PubMed Central

    Imase, Masato; Watanabe, Keiji; Aoyagi, Hideki; Tanaka, Hideo

    2008-01-01

    Chlorella sorokiniana IAM C-212 produces a polysaccharide gel, termed a sheath, under photoautotrophic conditions. The C. sorokiniana sheath is a suitable habitat for several symbiotic microorganisms because it ensures close proximity between the C. sorokiniana and symbionts. In this study, we established a method for increasing the volume of the sheath produced by C. sorokiniana, and proposed a method for constructing artificial communities of Chlorella and symbiotic microorganisms. The C. sorokiniana sheath was increased by addition of calcium chloride solution. The sheath resulted in coflocculation of C. sorokiniana and the associated symbiotic bacteria, thus strengthening the bacterial–Chlorella symbiotic association. An application of this technique was demonstrated by constructing a complex of C. sorokiniana and a propionate-degrading bacterium (PDS1). Although propionate inhibited the growth of axenic C. sorokiniana, the C. sorokiniana–PDS1 complex showed good growth in a medium containing a high concentration of propionate. PMID:18269632

  13. Microautoradiographic study of Rhodocyclus-related polyphosphate-accumulating bacteria in full-scale enhanced biological phosphorus removal plants.

    PubMed

    Kong, Yunhong; Nielsen, Jeppe Lund; Nielsen, Per Halkjaer

    2004-09-01

    The ecophysiology of uncultured Rhodocyclus-related polyphosphate-accumulating organisms (PAO) present in three full-scale enhanced biological phosphorus removal (EBPR) activated sludge plants was studied by using microautoradiography combined with fluorescence in situ hybridization. The investigations showed that these organisms were present in all plants examined and constituted 5 to 10, 10 to 15, and 17 to 22% of the community biomass. The behavior of these bacteria generally was consistent with the biochemical models proposed for PAO, based on studies of lab-scale investigations of enriched and often unknown PAO cultures. Rhodocyclus-related PAO were able to accumulate short-chain substrates, including acetate, propionate, and pyruvate, under anaerobic conditions, but they could not assimilate many other low-molecular-weight compounds, such as ethanol and butyrate. They were able to assimilate two substrates (e.g., acetate and propionate) simultaneously. Leucine and thymidine could not be assimilated as sole substrates and could only be assimilated as cosubstrates with acetate, perhaps serving as N sources. Glucose could not be assimilated by the Rhodocyclus-related PAO, but it was easily fermented in the sludge to products that were subsequently consumed. Glycolysis, and not the tricarboxylic acid cycle, was the source that provided the reducing power needed by the Rhodocyclus-related PAO to form the intracellular polyhydroxyalkanoate storage compounds during anaerobic substrate assimilation. The Rhodocyclus-related PAO were able to take up orthophosphate and accumulate polyphosphate when oxygen, nitrate, or nitrite was present as an electron acceptor. Furthermore, in the presence of acetate growth was sustained by using oxygen, as well as nitrate or nitrite, as an electron acceptor. This strongly indicates that Rhodocyclus-related PAO were able to denitrify and thus played a role in the denitrification occurring in full-scale EBPR plants.

  14. Impact of diets with a high content of greaves-meal protein or carbohydrates on faecal characteristics, volatile fatty acids and faecal calprotectin concentrations in healthy dogs.

    PubMed

    Hang, Ingrid; Heilmann, Romy M; Grützner, Niels; Suchodolski, Jan S; Steiner, Jörg M; Atroshi, Faik; Sankari, Satu; Kettunen, Anu; de Vos, Willem M; Zentek, Jürgen; Spillmann, Thomas

    2013-10-09

    Research suggests that dietary composition influences gastrointestinal function and bacteria-derived metabolic products in the dog colon. We previously reported that dietary composition impacts upon the faecal microbiota of healthy dogs. This study aims at evaluating the dietary influences on bacteria-derived metabolic products associated with the changes in faecal microbiota that we had previously reported. We fed high-carbohydrate starch based (HCS), [crude protein: 194 g/kg, starch: 438 g/kg], high-protein greaves-meal (HPGM), [crude protein: 609 g/kg, starch: 54 g/kg] and dry commercial (DC), [crude protein: 264 g/kg, starch: 277 g/kg] diets, and studied their effects on the metabolism of the colonic microbiota and faecal calprotectin concentrations in five Beagle dogs, allocated according to the Graeco-Latin square design. Each dietary period lasted for three weeks and was crossed-over with washout periods. Food intake, body weight, and faecal consistency scores, dry matter, pH, ammonia, volatile fatty acids (VFAs), and faecal canine calprotectin concentrations were determined. Faecal ammonia concentrations decreased with the HCS diet. All dogs fed the HPGM diet developed diarrhoea, which led to differences in faecal consistency scores between the diets. Faecal pH was higher with the HPGM diet. Moreover, decreases in propionic and acetic acids coupled with increases in branched-chain fatty acids and valeric acid caused changes in faecal total VFAs in dogs on the HPGM diet. Faecal canine calprotectin concentration was higher with the HPGM diet and correlated positively with valeric acid concentration. The HPGM diet led to diarrhoea in all dogs, and there were differences in faecal VFA profiles and faecal canine calprotectin concentrations.

  15. Complex formation equilibria of binary and ternary complexes involving 3,3-bis(1-methylimidazol-2yl)propionic acid and bio-relevant ligands as 1-aminocyclopropane carboxylic acid with reference to plant hormone

    NASA Astrophysics Data System (ADS)

    Shoukry, Mohamed M.; Hassan, Safaa S.

    2014-01-01

    The formation equilibria for the binary complexes of Cu(II) with 1-aminocyclopropane carboxylic acid (ACC) and 3,3-bis(1-methylimidazol-2-yl)propionic acid (BIMP) were investigated. ACC and BIMP form the complexes 1 1 0, 1 2 0 and 1 1 -1. The ternary complexes of Cu(II) with BIMP and biorelevant ligands as some selected amino acids, peptides and DNA constituents are formed in a stepwise mechanism. The stability constants of the complexes formed were determined and their distribution diagrams were evaluated. The kinetics of hydrolysis of glycine methyl ester in presence of [Cu(BIMP)]+ was investigated by pH-stat technique and the mechanism was discussed.

  16. Effect of sugar fatty acid esters on rumen fermentation in vitro.

    PubMed

    Wakita, M; Hoshino, S

    1987-11-01

    1. The effect of sugar fatty acid esters (SFEs; currently used as food additives for human consumption) on rumen volatile fatty acids (VFA) and gas production was studied with sheep rumen contents in vitro. 2. Some SFEs having monoester contents of more than 70% increased the molar proportion of propionate in conjunction with reduction in the acetate:propionate ratio when the individual SFE was added to rumen contents in a final concentration of 4 g/l. Laurate sugar ester was the most potent propionate enhancer and rumen gas depressor, the effective dose being as low as 1 g/l in a final concentration. Fatty acid esters other than SFEs had little, if any, effect on rumen VFA production and their molar proportions. 3. Approximately 50% of laurate sugar ester was hydrolysed by in vitro incubation with rumen fluid for 2 h. The addition of fatty acids and sucrose was also effective in the alterations of rumen VFA and gas production. However, the effect of SFEs on in vitro rumen fermentation was significantly greater than that of their constituent fatty acids or sucrose, or both. Accordingly, the effect appeared to be ascribed to the complex action of SFE itself and to its constituents, free fatty acids and sucrose. 4. SFEs, at the level of 4 g/l, reduced substantially the froth formation (ingesta volume increase) and seemed to be effective for the prevention of bloat.

  17. Elevated propionate and butyrate in fecal ferments of hydrolysates generated by oxalic acid treatment of corn bran arabinoxylan.

    PubMed

    Rumpagaporn, Pinthip; Reuhs, Brad L; Cantu-Jungles, Thaisa M; Kaur, Amandeep; Patterson, John A; Keshavarzian, Ali; Hamaker, Bruce R

    2016-12-07

    Previous work in our laboratory showed that alkali-solubilized corn arabinoxylan (CAX) has a slow initial, but later complete, in vitro human fecal fermentation. CAX and a moderately high molecular weight hydrolysate (CH) were propiogenic, and produced low levels of butyrate. Here, we show that oxalic acid-generated hydrolysates from CAX, which include a large xylooligosaccharide, and free arabinose fractions, increased short chain fatty acid (SCFA) production, which included relatively high levels of both propionate and butyrate, an unusual SCFA combination. Hydrolytic degradation of CAX by acid hydrolysis (0.05 M oxalic acid at 100 °C for 2 h) and subsequent graded ethanol precipitations were used to obtain mixtures with different molecular weight ranges. Ethanol-precipitated fractions (F 0-65%, F 65-75%, F 75-85%) were mostly lower than 100 kDa and F > 85% was composed of monosaccharides and oligosaccharides of DP 2-8. Oxalic acid treatment caused the removal of all single arabinose unit branch chains and some di/trisaccharide branch chains, producing lightly substituted xylan backbone fragments, most of which were in the oligosaccharide (DP < 10) size range. In vitro human fecal fermentation analyses showed all oxalic acid-hydrolysate fractions were slower fermenting than fructooligosaccharides (FOS), but produced similar or higher amounts of total SCFAs. Butyrate production in two hydrolyzate fractions was double that of CH, while propionate levels remained relatively high.

  18. Antibiotics in the human food chain: establishing no effect levels of tetracycline, neomycin, and erythromycin using a chemostat model of the human colonic microflora.

    PubMed

    Carman, Robert J; Simon, Mary Alice; Petzold, H Earl; Wimmer, Robert F; Batra, Monica R; Fernández, A Haydée; Miller, Margaret A; Bartholomew, Mary

    2005-11-01

    A chemostat model of the healthy human large bowel ecosystem was used to establish no effect levels for tetracycline, neomycin, and erythromycin. For each compound, the equivalent to four oral doses (0, 1.5, 15, and 150 mg/60 kg person/d) was studied. Concentrations of the test compounds in the chemostat medium were intended to simulate fecal levels that might be expected following consumption of food containing antibiotic residue and were based on published oral doses and fecal levels. We monitored the following parameters: short chain fatty acids, bile acids, sulfate reduction, azoreductase and nitroreductase activities, beta-glucosidase and beta-glucuronidase activities, a range of bacterial counts and, lastly, the susceptibility among sentinel bacteria to each test compound. Neomycin and erythromycin reduced bile acid metabolism. Neomycin elevated propionate levels and caused a marginal diminution in azoreductase activity. Based on our results, the no observed effect level (NOEL) of both tetracycline and erythromycin was 15 mg/60 kg person/d. The NOEL for neomycin was 1.5 mg/60 kg person/d.

  19. Culture-Dependent and -Independent Methods to Investigate the Predominant Microorganisms Associated with Wet Processed Coffee.

    PubMed

    Feng, Xiaomin; Dong, Honghong; Yang, Pan; Yang, Ruijuan; Lu, Jun; Lv, Jie; Sheng, Jun

    2016-08-01

    The fermentation process of Yunnan arabica coffee is a typical wet fermentation. Its excellent quality is closely related to microbes in the process of fermentation. The purpose of this study was to isolate and identify the microorganisms in the wet method of coffee processing in Yunnan Province, China. Microbial community structure and dominant bacterial species were evaluated by traditional cultivated separation method and PCR-DGGE technology, and were further analyzed in combination with the changes of organic acid content, activity of pectinase, and physical parameters (pH and temperature). A large number of microorganisms which can produce pectinase were found. Among them, Enterobacter cowanii, Pantoea agglomerans, Enterobacteriaceae bacterium, and Rahnella aquatilis were the predominant gram-negative bacteria, Bacillus cereus was the predominant gram-positive bacterium, Pichia kluyveri, Hanseniaspora uvarum, and Pichia fermentans were the predominant yeasts, and all those are pectinase-producing microorganisms. As for the contents of organic acids, oxalic was the highest, followed by acetic and lactic acids. Butyrate and propionate, which were unfavorable during the fermentation period, were barely discovered.

  20. Microbial acetogenesis as a source of organic acids in ancient Atlantic Coastal Plain sediments

    USGS Publications Warehouse

    Chapelle, F.H.; Bradley, P.M.

    1996-01-01

    Field and laboratory evidence shows that deeply buried (90-888 m) fine-grained sediments of the Atlantic Coastal Plain contain viable acetogenic microorganisms, and that these microorganisms actively produce organic acids. Concentrations of formate, acetate, and propionate in pore waters extracted from fine-grained sediments ranged from 50 ??M to 5 mM and were much higher than in adjacent pore waters associated with sandy sediments (<2 ??M). Laboratory studies showed that asceptically cored fine-grained sediments incubated under a H2 atmosphere produced formate and acetate, and that H14CO-3 was converted to 14C-acetate and 14C-formate over time. An enrichment culture of these acetogenic microorganisms was recovered from one long-term incubation that showed the presence of several morphologically distinct gram-positive, rod-shaped bacteria. These microorganisms were capable of growth under autotrophic (H2 + CO2), heterotrophic (syringate), and mixotrophic (H2 + CO2 + syringate) conditions. These results suggest that microbial acetogenesis, rather than abiotic processes, is the most important organic acid-producing mechanism during low-temperature (???30 ??C) diagenesis of Atlantic Coastal Plain sediments.

  1. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep.

    PubMed

    Lettat, Abderzak; Nozière, Pierre; Silberberg, Mathieu; Morgavi, Diego P; Berger, Claudette; Martin, Cécile

    2012-07-19

    Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA) were induced by feed chalenges in three groups of four wethers intraruminally dosed with wheat, corn or beet pulp. In each group, wethers were either not supplemented (C) or supplemented with Propionibacterium P63 alone (P) or combined with L. plantarum (Lp + P) or L. rhamnosus (Lr + P). Compared with C, all the probiotics stimulated lactobacilli proliferation, which reached up to 25% of total bacteria during wheat-induced lactic acidosis. This induced a large increase in lactate concentration, which decreased ruminal pH. During the corn-induced butyric SARA, Lp + P decreased Prevotella spp. proportion with a concomitant decrease in microbial amylase activity and total volatile fatty acids concentration, and an increase in xylanase activity and pH. Relative to the beet pulp-induced propionic SARA, P and Lr + P improved ruminal pH without affecting the microbial or fermentation characteristics. Regardless of acidosis type, denaturing gradient gel electrophoresis revealed that probiotic supplementations modified the bacterial community structure. This work showed that the effectiveness of the bacterial probiotics tested depended on the acidosis type. Although these probiotics were ineffective in lactic acidosis because of a deeply disturbed rumen microbiota, some of the probiotics tested may be useful to minimize the occurrence of butyric and propionic SARA in sheep. However, their modes of action need to be further investigated.

  2. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep

    PubMed Central

    2012-01-01

    Background Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Results Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA) were induced by feed chalenges in three groups of four wethers intraruminally dosed with wheat, corn or beet pulp. In each group, wethers were either not supplemented (C) or supplemented with Propionibacterium P63 alone (P) or combined with L. plantarum (Lp + P) or L. rhamnosus (Lr + P). Compared with C, all the probiotics stimulated lactobacilli proliferation, which reached up to 25% of total bacteria during wheat-induced lactic acidosis. This induced a large increase in lactate concentration, which decreased ruminal pH. During the corn-induced butyric SARA, Lp + P decreased Prevotella spp. proportion with a concomitant decrease in microbial amylase activity and total volatile fatty acids concentration, and an increase in xylanase activity and pH. Relative to the beet pulp-induced propionic SARA, P and Lr + P improved ruminal pH without affecting the microbial or fermentation characteristics. Regardless of acidosis type, denaturing gradient gel electrophoresis revealed that probiotic supplementations modified the bacterial community structure. Conclusion This work showed that the effectiveness of the bacterial probiotics tested depended on the acidosis type. Although these probiotics were ineffective in lactic acidosis because of a deeply disturbed rumen microbiota, some of the probiotics tested may be useful to minimize the occurrence of butyric and propionic SARA in sheep. However, their modes of action need to be further investigated. PMID:22812531

  3. [Isolation and identification of a lactate-utilizing, butyrate-producing bacterium and its primary metabolic characteristics].

    PubMed

    Liu, Wei; Zhu, Wei-yun; Yao, Wen; Mao, Sheng-yong

    2007-06-01

    The distal mammalian gut harbors prodigiously abundant microbes, which provide unique metabolic traits to host. A lactate-utilizing, butyrate-producing bacterium, strain LB01, was isolated from adult swine feces by utilizing modified Hungate technique with rumen liquid-independent YCFA medium supplemented with lactate as the single carbon source. It was an obligate anaerobic, Gram positive bacterium, and could utilize glucose, fructose, maltose and lactate with a large amount of gas products. 16S rRNA sequence analysis revealed that it had the high similarity with members of the genus Megasphaera. The metabolic characteristics of strain LB01 was investigated by using in vitro fermentation system. Lactate at the concentration of 65 mmol/L in YCFA medium was rapidly consumed within 9 hours and was mainly converted to propionate and butyrate after 24h. As the level of acetate declined, the concentration of butyrate rose only in the presence of glucose, suggesting that butyrate could possibly be synthesized by the acetyl CoA: butyryl CoA transferase. When co-cultured with lactic acid bacteria strain K9, strain LB01 evidently reduced the concentration of lactate produced by strain K9 and decelerated the rapid pH drop, finally producing 12.11 mmol/L butyrate and 4.06 mmol/L propionate. The metabolic characteristics that strain LB01 efficiently converts toxic lactate and excessive acetate to butyrate can prevent lactate and acetate accumulation in the large intestine and maintain the slightly acidic environment of the large intestine, consequently revealing that stain LB01 could act as a potential probiotics.

  4. Microbial responses to chitin and chitosan in oxic and anoxic agricultural soil slurries

    NASA Astrophysics Data System (ADS)

    Wieczorek, A. S.; Hetz, S. A.; Kolb, S.

    2014-06-01

    Microbial degradation of chitin in soil substantially contributes to carbon cycling in terrestrial ecosystems. Chitin is globally the second most abundant biopolymer after cellulose and can be deacetylated to chitosan or can be hydrolyzed to N,N'-diacetylchitobiose and oligomers of N-acetylglucosamine by aerobic and anaerobic microorganisms. Which pathway of chitin hydrolysis is preferred by soil microbial communities is unknown. Supplementation of chitin stimulated microbial activity under oxic and anoxic conditions in agricultural soil slurries, whereas chitosan had no effect. Thus, the soil microbial community likely was more adapted to chitin as a substrate. In addition, this finding suggested that direct hydrolysis of chitin was preferred to the pathway that starts with deacetylation. Chitin was apparently degraded by aerobic respiration, ammonification, and nitrification to carbon dioxide and nitrate under oxic conditions. When oxygen was absent, fermentation products (acetate, butyrate, propionate, hydrogen, and carbon dioxide) and ammonia were detected, suggesting that butyric and propionic acid fermentation, along with ammonification, were likely responsible for anaerobic chitin degradation. In total, 42 different chiA genotypes were detected of which twenty were novel at an amino acid sequence dissimilarity of less than 50%. Various chiA genotypes responded to chitin supplementation and affiliated with a novel deep-branching bacterial chiA genotype (anoxic conditions), genotypes of Beta- and Gammaproteobacteria (oxic and anoxic conditions), and Planctomycetes (oxic conditions). Thus, this study provides evidence that detected chitinolytic bacteria were catabolically diverse and occupied different ecological niches with regard to oxygen availability enabling chitin degradation under various redox conditions on community level.

  5. Microbial responses to chitin and chitosan in oxic and anoxic agricultural soil slurries

    NASA Astrophysics Data System (ADS)

    Wieczorek, A. S.; Hetz, S. A.; Kolb, S.

    2014-02-01

    Chitin is the second most abundant biopolymer in terrestrial ecosystems and is subject to microbial degradation. Chitin can be deacetylated to chitosan or can be hydrolyzed to N,N'-diacetylchitobiose and oligomers of N-acetylglucosamine by aerobic and anaerobic microorganisms. Which pathway of chitin hydrolysis is preferred by soil microbial communities has previously been unknown. Supplementation of chitin stimulated microbial activity under oxic and anoxic conditions in agricultural soil slurries, whereas chitosan had no effect. Thus, the soil microbial community likely was more adapted to chitin as a substrate. In addition, this finding suggested that direct hydrolysis of chitin was preferred to the pathway that starts with deacetylation. Chitin was apparently degraded by aerobic respiration, ammonification, and nitrification to carbon dioxide and nitrate under oxic conditions. When oxygen was absent, fermentation products (acetate, butyrate, propionate, hydrogen, carbon dioxide) and ammonia were detected, suggesting that butyric and propionic acid fermentation were along with ammonification likely responsible for apparent anaerobic chitin degradation. In total, 42 different chiA genotypes were detected of which twenty were novel at an amino acid sequence dissimilarity of >50%. Various chiA genotypes responded to chitin supplementation and affiliated with a novel deep-branching bacterial chiA genotype (anoxic conditions), genotypes of Beta- and Gammaproteobacteria (oxic and anoxic conditions), and Planctomycetes (oxic conditions). Thus, this study provides evidence that detected chitinolytic bacteria were catabolically diverse and occupied different ecological niches with regard to oxygen availability enabling chitin degradation under various redox conditions at the level of the community.

  6. Biotechnology for producing fuels and chemicals from biomass. Volume 2: Fermentation chemicals from biomass

    NASA Astrophysics Data System (ADS)

    Villet, R.

    1981-02-01

    The technological and economic feasibility of producing chemicals by fermentation is discussed: acetone; butanol; acetic acid; citric acid; 2,3-butanediol, and propionic acid. Improved cost of fermentative production will hinge on improving yields and using cellulosic feedstocks. The market for acetic acid is likely to grow 5 percent to 7 percent/yr. A potential process for production is the fermentation of hydrolyzed cellulosic material to ethanol followed by chemical conversion to acetic acid. The feedstock cost is 15 to 20 percent of the overall cost of production. The anticipated 5 percent growth in demand for citric acid could be enhanced by using it to displace phosphates in detergent manufacture. A number of useful chemicals can be derived from 2,3-butanediol, which has not been produced commercially on a large scale. The commercial fermentative production of propionic acid has not yet been developed.

  7. Lactate and Acrylate Metabolism by Megasphaera elsdenii under Batch and Steady-State Conditions

    PubMed Central

    Prabhu, Rupal; Altman, Elliot

    2012-01-01

    The growth of Megasphaera elsdenii on lactate with acrylate and acrylate analogues was studied under batch and steady-state conditions. Under batch conditions, lactate was converted to acetate and propionate, and acrylate was converted into propionate. Acrylate analogues 2-methyl propenoate and 3-butenoate containing a terminal double bond were similarly converted into their respective saturated acids (isobutyrate and butyrate), while crotonate and lactate analogues 3-hydroxybutyrate and (R)-2-hydroxybutyrate were not metabolized. Under carbon-limited steady-state conditions, lactate was converted to acetate and butyrate with no propionate formed. As the acrylate concentration in the feed was increased, butyrate and hydrogen formation decreased and propionate was increasingly generated, while the calculated ATP yield was unchanged. M. elsdenii metabolism differs substantially under batch and steady-state conditions. The results support the conclusion that propionate is not formed during lactate-limited steady-state growth because of the absence of this substrate to drive the formation of lactyl coenzyme A (CoA) via propionyl-CoA transferase. Acrylate and acrylate analogues are reduced under both batch and steady-state growth conditions after first being converted to thioesters via propionyl-CoA transferase. Our findings demonstrate the central role that CoA transferase activity plays in the utilization of acids by M. elsdenii and allows us to propose a modified acrylate pathway for M. elsdenii. PMID:23023753

  8. A comprehensive analysis of myocardial substrate preference emphasizes the need for a synchronized fluxomic/metabolomic research design.

    PubMed

    Ragavan, Mukundan; Kirpich, Alexander; Fu, Xiaorong; Burgess, Shawn C; McIntyre, Lauren M; Merritt, Matthew E

    2017-06-01

    The heart oxidizes fatty acids, carbohydrates, and ketone bodies inside the tricarboxylic acid (TCA) cycle to generate the reducing equivalents needed for ATP production. Competition between these substrates makes it difficult to estimate the extent of pyruvate oxidation. Previously, hyperpolarized pyruvate detected propionate-mediated activation of carbohydrate oxidation, even in the presence of acetate. In this report, the optimal concentration of propionate for the activation of glucose oxidation was measured in mouse hearts perfused in Langendorff mode. This study was performed with a more physiologically relevant perfusate than the previous work. Increasing concentrations of propionate did not cause adverse effects on myocardial metabolism, as evidenced by unchanged O 2 consumption, TCA cycle flux, and developed pressures. Propionate at 1 mM was sufficient to achieve significant increases in pyruvate dehydrogenase flux (3×), and anaplerosis (6×), as measured by isotopomer analysis. These results further demonstrate the potential of propionate as an aid for the correct estimation of total carbohydrate oxidative capacity in the heart. However, liquid chromotography/mass spectroscopy-based metabolomics detected large changes (~30-fold) in malate and fumarate pool sizes. This observation leads to a key observation regarding mass balance in the TCA cycle; flux through a portion of the cycle can be drastically elevated without changing the O 2 consumption. Copyright © 2017 the American Physiological Society.

  9. Rates of production of acetate, propionate, and butyrate in the rumen of lactating dairy cows given normal and low-roughage diets.

    PubMed

    Sutton, J D; Dhanoa, M S; Morant, S V; France, J; Napper, D J; Schuller, E

    2003-11-01

    Five lactating dairy cows with a permanent cannula in the rumen were given (kg DM/d) a normal diet (7.8 concentrates, 5.1 hay) or a low-roughage (LR) diet (11.5 concentrates, 1.2 hay) in two meals daily in a two-period crossover design. Milk fat (g/kg) was severely reduced on diet LR. To measure rates of production of individual volatile fatty acids (VFA) in the rumen, 0.5 mCi 1-(14)C-acetic acid, 2-(14)C-propionic acid, or 1-(14)C-n-butyric acid were infused into the rumen for 22 h at intervals of 2 to 6 d; rumen samples were taken over the last 12 h. To measure rumen volume, we infused Cr-EDTA into the rumen continuously, and polyethylene glycol was injected 2 h before the morning feed. Results were very variable, so volumes measured by rumen emptying were used instead. Net production of propionic acid more than doubled on LR, but acetate and butyrate production was only numerically lower. Net production rates pooled across both diets were significantly related to concentrations for each VFA. Molar proportions of net production were only slightly higher than molar proportions of concentrations for acetate and propionate but were lower for butyrate. The net energy value (MJ/d) of production of the three VFA increased from 89.5 on normal to 109.1 on LR, equivalent to 55 and 64% of digestible energy, respectively. Fully interchanging, three-pool models of VFA C fluxes are presented. It is concluded that net production rates of VFA can be measured in non-steady states without the need to measure rumen volumes.

  10. The role of pH in determining the species composition of the human colonic microbiota.

    PubMed

    Duncan, Sylvia H; Louis, Petra; Thomson, John M; Flint, Harry J

    2009-08-01

    The pH of the colonic lumen varies with anatomical site and microbial fermentation of dietary residue. We have investigated the impact of mildly acidic pH, which occurs in the proximal colon, on the growth of different species of human colonic bacteria in pure culture and in the complete microbial community. Growth was determined for 33 representative human colonic bacteria at three initial pH values (approximately 5.5, 6.2 and 6.7) in anaerobic YCFA medium, which includes a mixture of short-chain fatty acids (SCFA) with 0.2% glucose as energy source. Representatives of all eight Bacteroides species tested grew poorly at pH 5.5, as did Escherichia coli, whereas 19 of the 23 gram-positive anaerobes tested gave growth rates at pH 5.5 that were at least 50% of those at pH 6.7. Growth inhibition of B. thetaiotaomicron at pH 5.5 was increased by the presence of the SCFA mix (33 mM acetate, 9 mM propionate and 1 mM each of iso-valerate, valerate and iso-butyrate). Analysis of amplified 16S rRNA sequences demonstrated a major pH-driven shift within a human faecal bacterial community in a continuous flow fermentor. Bacteroides spp. accounted for 27% of 16S rRNA sequences detected at pH 5.5, but 86% of sequences at pH 6.7. Conversely, butyrate-producing gram-positive bacteria related to Eubacterium rectale represented 50% of all 16S rRNA sequences at pH 5.5, but were not detected at pH 6.7. Inhibition of the growth of a major group of gram-negative bacteria at mildly acidic pH apparently creates niches that can be exploited by more low pH-tolerant microorganisms.

  11. Application of Fourier transform infrared spectroscopy for monitoring short-chain free fatty acids in Swiss cheese.

    PubMed

    Koca, N; Rodriguez-Saona, L E; Harper, W J; Alvarez, V B

    2007-08-01

    Short-chain free fatty acids (FFA) are important sources of cheese flavor and have been reported to be indicators for assessing quality. The objective of this research was to develop a simple and rapid screening tool for monitoring the short-chain FFA contents in Swiss cheese by using Fourier transform infrared spectroscopy (FTIR). Forty-four Swiss cheese samples were evaluated by using a MIRacle three-reflection diamond attenuated total reflectance (ATR) accessory. Two different sampling techniques were used for FTIR/ATR measurement: direct measurement of Swiss cheese slices (approximately 0.5 g) and measurement of a water-soluble fraction of cheese. The amounts of FFA (propionic, acetic, and butyric acids) in the water-soluble fraction of samples were analyzed by gas chromatography-flame ion-ization detection as a reference method. Calibration models for both direct measurement and the water-soluble fraction of cheese were developed based on a cross-validated (leave-one-out approach) partial least squares regression by using the regions of 3,000 to 2,800, 1,775 to 1,680, and 1,500 to 900 cm(-1) for short-chain FFA in cheese. Promising performance statistics were obtained for the calibration models of both direct measurement and the water-soluble fraction, with improved performance statistics obtained from the water-soluble extract, particularly for propionic acid. Partial least squares models generated from FTIR/ATR spectra by direct measurement of cheeses gave standard errors of cross-validation of 9.7 mg/100 g of cheese for propionic acid, 9.3 mg/100 g of cheese for acetic acid, and 5.5 mg/100 g of cheese for butyric acid, and correlation coefficients >0.9. Standard error of cross-validation values for the water-soluble fraction were 4.4 mg/100 g of cheese for propionic acid, 9.2 mg/100 g of cheese for acetic acid, and 5.2 mg/100 g of cheese for butyric acid with correlation coefficients of 0.98, 0.95, and 0.92, respectively. Infrared spectroscopy and chemometrics accurately and precisely predicted the short-chain FFA content in Swiss cheeses and in the water-soluble fraction of the cheese.

  12. Effects of Bacillus subtilis natto and Different Components in Culture on Rumen Fermentation and Rumen Functional Bacteria In Vitro.

    PubMed

    Sun, Peng; Li, Jinan; Bu, Dengpan; Nan, Xuemei; Du, Hong

    2016-05-01

    This study was to investigate the effects of live or autoclaved Bacillus subtilis natto, their fermented products and media on rumen fermentation and rumen functional bacteria in vitro. Rumen fluid from three multiparous lactating Holstein cows was combined and transferred into serum bottles after diluted. Fifteen serum bottles were divided into five treatments, which were designed as following: CTR (the fermentation of 0.5 g TMR and ruminal fluids from dairy cows), LBS (CTR plus a minimum of 10(11) cfu live Bacillus subtilis natto), ABS (CTR plus a minimum of 10(11) cfu autoclaved Bacillus subtilis natto), BSC (CTR plus 1 ml Bacillus subtilis natto fermentation products without bacteria), and BSM (CTR plus 1 ml liquid fermentation medium). When separated from the culture, live Bacillus subtilis natto individually increased the concentrations of ammonia-N (P < 0.01), MCP production (P < 0.01), and tended to elevate total VFA (P = 0.07), but decreased the ratio of acetate and propionate (P < 0.01). Autoclaved Bacillus subtilis natto has the similar function with the live bacteria except for the ratio of acetate and propionate. Except B. fibrisolvens, live or autoclaved Bacillus subtilis natto did not influence or decreased the 16S rRNA gene quantification of the detected bacteria. BSC and BSM altered the relative expression of certain functional bacteria in the rumen. These results indicated that it was Bacillus subtilis natto thalli that played the important role in promoting rumen fermentation when applied as a probiotic in dairy ration.

  13. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the herbicide glufosinate-ammonium (butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...-propionic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl)butanoic acid equivalents, in or on the... herbicide glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl)-, monoammonium salt and...

  14. Synergism between hydrogen peroxide and seventeen acids against five agri-food-borne fungi and one yeast strain.

    PubMed

    Martin, H; Maris, P

    2012-12-01

    The objective of this study was to evaluate fungicidal efficacy of hydrogen peroxide administered in combination with 17 mineral and organic acids authorized for use in the food industry. The assays were performed on a 96-well microplate using a microdilution technique based on the checkerboard titration method. The six selected strains (one yeast and five fungi) were reference strains and strains representative of contaminating fungi found in the food industry. Each synergistic hydrogen peroxide/acid combination found after fifteen minutes contact time at 20 °C in distilled water was then tested in conditions simulating four different use conditions. Twelve combinations were synergistic in distilled water, eleven of these remained synergistic with one or more of the four mineral and organic interfering substances selected. Hydrogen peroxide/formic acid combination remained effective against four strains and was never antagonistic against the other two fungi. Combinations with propionic acid and acetic acid stayed synergistic against two strains. Those with oxalic acid and lactic acid kept their synergism only against Candida albicans. No synergism was detected against Penicillium cyclopium. Synergistic combinations of disinfectants were revealed, among them the promising hydrogen peroxide/formic acid combination. A rapid screening method developed in our laboratory for bacteria was adapted to fungi and used to reveal the synergistic potential of disinfectants and/or sanitizers combinations. © 2012 The Society for Applied Microbiology.

  15. An In Vitro Model of the Horse Gut Microbiome Enables Identification of Lactate-Utilizing Bacteria That Differentially Respond to Starch Induction

    PubMed Central

    Biddle, Amy S.; Black, Samuel J.; Blanchard, Jeffrey L.

    2013-01-01

    Laminitis is a chronic, crippling disease triggered by the sudden influx of dietary starch. Starch reaches the hindgut resulting in enrichment of lactic acid bacteria, lactate accumulation, and acidification of the gut contents. Bacterial products enter the bloodstream and precipitate systemic inflammation. Hindgut lactate levels are normally low because specific bacterial groups convert lactate to short chain fatty acids. Why this mechanism fails when lactate levels rapidly rise, and why some hindgut communities can recover is unknown. Fecal samples from three adult horses eating identical diets provided bacterial communities for this in vitro study. Triplicate microcosms of fecal slurries were enriched with lactate and/or starch. Metabolic products (short chain fatty acids, headspace gases, and hydrogen sulfide) were measured and microbial community compositions determined using Illumina 16S rRNA sequencing over 12-hour intervals. We report that patterns of change in short chain fatty acid levels and pH in our in vitro system are similar to those seen in in vivo laminitis induction models. Community differences between microcosms with disparate abilities to clear excess lactate suggest profiles conferring resistance of starch-induction conditions. Where lactate levels recover following starch induction conditions, propionate and acetate levels rise correspondingly and taxa related to Megasphaera elsdenii reach levels exceeding 70% relative abundance. In lactate and control cultures, taxa related to Veillonella montpellierensis are enriched as lactate levels fall. Understanding these community differences and factors promoting the growth of specific lactate utilizing taxa may be useful to prevent acidosis under starch-induction conditions. PMID:24098591

  16. An in vitro model of the horse gut microbiome enables identification of lactate-utilizing bacteria that differentially respond to starch induction.

    PubMed

    Biddle, Amy S; Black, Samuel J; Blanchard, Jeffrey L

    2013-01-01

    Laminitis is a chronic, crippling disease triggered by the sudden influx of dietary starch. Starch reaches the hindgut resulting in enrichment of lactic acid bacteria, lactate accumulation, and acidification of the gut contents. Bacterial products enter the bloodstream and precipitate systemic inflammation. Hindgut lactate levels are normally low because specific bacterial groups convert lactate to short chain fatty acids. Why this mechanism fails when lactate levels rapidly rise, and why some hindgut communities can recover is unknown. Fecal samples from three adult horses eating identical diets provided bacterial communities for this in vitro study. Triplicate microcosms of fecal slurries were enriched with lactate and/or starch. Metabolic products (short chain fatty acids, headspace gases, and hydrogen sulfide) were measured and microbial community compositions determined using Illumina 16S rRNA sequencing over 12-hour intervals. We report that patterns of change in short chain fatty acid levels and pH in our in vitro system are similar to those seen in in vivo laminitis induction models. Community differences between microcosms with disparate abilities to clear excess lactate suggest profiles conferring resistance of starch-induction conditions. Where lactate levels recover following starch induction conditions, propionate and acetate levels rise correspondingly and taxa related to Megasphaeraelsdenii reach levels exceeding 70% relative abundance. In lactate and control cultures, taxa related to Veillonellamontpellierensis are enriched as lactate levels fall. Understanding these community differences and factors promoting the growth of specific lactate utilizing taxa may be useful to prevent acidosis under starch-induction conditions.

  17. Development of [3H]2-Carboxy-4,6-dichloro-1H-indole-3-propionic Acid ([3H]PSB-12150): A Useful Tool for Studying GPR17

    PubMed Central

    2014-01-01

    The recently described synthetic GPR17 agonist 2-carboxy-4,6-dichloro-1H-indole-3-propionic acid (1) was prepared in tritium-labeled form by catalytic hydrogenation of the corresponding propenoic acid derivative 8 with tritium gas. The radioligand [3H]PSB-12150 (9) was obtained with a specific activity of 17 Ci/mmol (629 GBq/mmol). It showed specific and saturable binding to a single binding site in membrane preparations from Chinese hamster ovary cells recombinantly expressing the human GPR17. A competition assay procedure was established, which allows the determination of ligand binding affinities. PMID:24900835

  18. Development of [(3)H]2-Carboxy-4,6-dichloro-1H-indole-3-propionic Acid ([(3)H]PSB-12150): A Useful Tool for Studying GPR17.

    PubMed

    Köse, Meryem; Ritter, Kirsten; Thiemke, Katharina; Gillard, Michel; Kostenis, Evi; Müller, Christa E

    2014-04-10

    The recently described synthetic GPR17 agonist 2-carboxy-4,6-dichloro-1H-indole-3-propionic acid (1) was prepared in tritium-labeled form by catalytic hydrogenation of the corresponding propenoic acid derivative 8 with tritium gas. The radioligand [(3)H]PSB-12150 (9) was obtained with a specific activity of 17 Ci/mmol (629 GBq/mmol). It showed specific and saturable binding to a single binding site in membrane preparations from Chinese hamster ovary cells recombinantly expressing the human GPR17. A competition assay procedure was established, which allows the determination of ligand binding affinities.

  19. ION-EXCLUSION CHROMATOGRAPHIC DETERMINATION OF CARBOXYLIC ACIDS USED TO SUPPORT THE MICROBIALLY MEDIATED REDUCTIVE DECHLORINATION OF TETRACHLOROETHENE

    EPA Science Inventory

    An analytical method was developed for the determination of lactic acid, formic acid, acetic acid, propionic acid, and butyric acid in environmental microcosm samples using ion-exclusion chromatography. The chromatographic behavior of various eluents was studied to determine the ...

  20. Comprehensive monitoring and management of a long-term thermophilic CSTR treating coffee grounds, coffee liquid, milk waste, and municipal sludge.

    PubMed

    Shofie, Mohammad; Qiao, Wei; Li, Qian; Takayanagi, Kazuyuki; Li, Yu-You

    2015-09-01

    The CSTR process has previously not been successfully applied to treat coffee residues under thermophilic temperature and long term operation. In this experiment, the CSTR was fed with mixture substrate (TS ∼ 70 g/L) of coffee grounds, coffee wastewater, milk waste and municipal sludge and it was operated under 55 °C for 225 days. A steady state was achieved under HRT 30 days and OLR 4.0 kg-COD/m(3)/d. However, there was an 35 days inhibition with VFA accumulation (propionic acid 700-1900 mg/L) when doubling the OLR by shortening HRT to 15 days. But, an addition of microelements and sulfate (0.5 g/L) in feedstock increased reactor resilience and stability under high loading rate and propionic acid stress. Continuous monitoring of hydrogen in biogas indicated the imbalance of acetogenesis. The effectiveness of comprehensive parameters (total VFA, propionic acid, IA/PA, IA/TA and CH4 content) was proved to manage the thermophilic system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. [Isolation and in vitro metabolic characterization of a lactate-utilizing bacterium from goat rumen].

    PubMed

    Long, Liming; Mao, Shengyong; Su, Yong; Zhu, Weiyun

    2008-12-01

    A lactate-utilizing, propionate-producing bacterium, strain L9, was isolated from rumen of goat fed with high concentrate by utilizing modified Hungate technique and anaerobic culture technique. The effect of the strain L9 culture on the rumen fermentation was further studied. According to the characteristics of morphology, physiology, biochemistry tests and sequence comparison of 16S rRNA gene, strain L9 was identified as selenomonas ruminantium. The influence of strain L9 culture on in vitro rumen fermentation was studied using mixed rumen micro-organisms of goats as inoculums. The results of the metabolism experiment showed that it was capable of using lactate as the sole carbon source, and 90 mmol/L lactate in LH medium could be completely utilized after 24 h incubation. As compared with the control, strain L9 culture addition significantly increased the total volatile fatty acids (TVFA), the percentage of propionate and pH value, while reduced the ratio of acetate to propionate and lactate production (P < 0.05). The results suggested that strain L9 can reduce lactic acid production and enhance the TVFA and propionate production in in vitro fermentation, and thus could be beneficial for the fermentation of rumen microorganisms.

  2. 21 CFR 177.1200 - Cellophane.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... salt Cellulose acetate butyrate Cellulose acetate propionate Cetyl alcohol Clay, natural Coconut oil fatty acid (C12-C18) diethanolamide, coconut oil fatty acid (C12-C18) diethanolamine soap, and...

  3. Regulation of the Docosapentaenoic Acid/Docosahexaenoic Acid Ratio (DPA/DHA Ratio) in Schizochytrium limacinum B4D1.

    PubMed

    Zhang, Ke; Li, Huidong; Chen, Wuxi; Zhao, Minli; Cui, Haiyang; Min, Qingsong; Wang, Haijun; Chen, Shulin; Li, Demao

    2017-05-01

    Docosapentaenoic acid/docosahexaenoic acid ratio (DPA/DHA ratio) in Schizochytrium was relatively stable. But ideally the ratio of DPA/DHA will vary according to the desired end use. This study reports several ways of modulating the DPA/DHA ratio. Incubation times changed the DPA/DHA ratio, and changes in this ratio were associated with the variations in the saturated fatty acid (SFAs) content. Propionic acid sharply increased the SFAs content in lipids, dramatically decreased the even-chain SFAs content, and reduced the DPA/DHA ratio. Pentanoic acid (C5:0) and heptanoic acid (C7:0) had similar effects as propionic acid, whereas butyric acid (C4:0), hexanoic acid (C6:0), and octanoic acid (C8:0) did not change the fatty acid profile and the DPA/DHA ratio. Transcription analyses show that β-oxidation might be responsible for this phenomenon. Iodoacetamide upregulated polyunsaturated fatty acid (PUFA) synthase genes, reduced the DHA content, and improved the DPA content, causing the DPA/DHA ratio to increase. These results present new insights into the regulation of the DPA/DHA ratio.

  4. [Isolation, identification and rumen fermentation characteristics of Propionibacterium acnes].

    PubMed

    Wu, Ling; Zhao, Mingjuan; Xia, Cheng; Ni, Hongbo; Zhang, Hongyou

    2009-02-01

    Characteristic of energy metabolism in ruminant is a negative energy balance in perinatal period. Propionic acid from ruminal microbe fermentation is a vital glyconeogenesis substrate for preventing negative energy balance. We isolated and screened a Propionibacterium acnes strain from health cow rumen fluid, and studied its rumen fermentation characteristics. A Propionibacterium acnes strain from rumen fluid of health cow with permanent rumen fistula under sterile condition was isolated by segregation procedure of anaerobic bacterium and Sodium Lactate Broth (SLB), and identified by extraction of the genome DNA, cloning of the 16S rRNA gene, and sequencing. We studied the effect of the strain on pH, volatile fatty acid and lactic acid in rumen fluid in vitro and in vivo. A bacterium isolated from health cow rumen fluid was identified as Propionibacterium acnes by morphology, biochemical characteristics and sequence homology. In vitro, pH in rumen fluid decreased to the lowest after rumen fermentation of the strain for 12 h, then increased gradually. However, concentration of volatile fatty acid, such as acetic acid, propionic acid and butyric acid, increased to the highest after rumen fermentation of the strain for 12 h, then decreased gradually in vitro. The concentration of lactic acid and ratio of acetate to propionate decreased overall in vitro. In vivo, pH in rumen fluid decreased overall, concentration, of the volatile fatty acid increased overall. A strain of Propionibacterium acnes was isolated successfully from health cow rumen fluid. It is an important basis to develop microecological preparation for preventing cows' negative energy balance in perinatal period in future.

  5. Geovibrio ferrireducens, a phylogenetically distinct dissimilatory Fe(III)-reducing bacterium

    USGS Publications Warehouse

    Caccavo, F.; Coates, J.D.; Rossello-Mora, R. A.; Ludwig, W.; Schleifer, K.H.; Lovley, D.R.; McInerney, M.J.

    1996-01-01

    A new, phylogenetically distinct, dissimilatory, Fe(III)-reducing bacterium was isolated from surface sediment of a hydrocarbon-contaminated ditch. The isolate, designated strain PAL-1, was an obligately anaerobic, non-fermentative, motile, gram-negative vibrio. PAL-1 grew in a defined medium with acetate as electron donor and ferric pyrophosphate, ferric oxyhydroxide, ferric citrate, Co(III)-EDTA, or elemental sulfur as sole electron acceptor. PAL-1 also used proline, hydrogen, lactate, propionate, succinate, fumarate, pyruvate, or yeast extract as electron donors for Fe(III) reduction. It is the first bacterium known to couple the oxidation of an amino acid to Fe(III) reduction. PAI-1 did not reduce oxygen, Mn(IV), U(VI), Cr(VI), nitrate, sulfate, sulfite, or thiosulfate with acetate as the electron donor. Cell suspensions of PAL-1 exhibited dithionite-reduced minus air-oxidized difference spectra that were characteristic of c-type cytochromes. Analysis of the 16S rRNA gene sequence of PAL-1 showed that the strain is not related to any of the described metal-reducing bacteria in the Proteobacteria and, together with Flexistipes sinusarabici, forms a separate line of descent within the Bacteria. Phenotypically and phylogenetically, strain PAI-1 differs from all other described bacteria, and represents the type strain of a new genus and species. Geovibrio ferrireducens.

  6. Degradation of lignocelluloses in rice straw by BMC-9, a composite microbial system.

    PubMed

    Zhao, Hongyan; Yu, Hairu; Yuan, Xufeng; Piao, Renzhe; Li, Hulin; Wang, Xiaofen; Cui, Zongjun

    2014-05-01

    To evaluate the potential utility of pretreatment of raw biomass with a complex microbial system, we investigated the degradation of rice straw by BMC-9, a lignocellulose decomposition strain obtained from a biogas slurry compost environment. The degradation characteristics and corresponding changes in the bacterial community were assessed. The results showed that rapid degradation occurred from day 0 to day 9, with a peak total biomass bacterium concentration of 3.3 × 10(8) copies/ml on day 1. The pH of the fermentation broth declined initially and then increased, and the mass of rice straw decreased steadily. The highest concentrations of volatile fatty acid contents (0.291 mg/l lactic acid, 0.31 mg/l formic acid, 1.93 mg/l acetic acid, and 0.73 mg/l propionic acid) as well as the highest xylanse activity (1.79 U/ml) and carboxymethyl cellulase activity (0.37 U/ml) occurred on day 9. The greatest diversity among the microbial community also occurred on day 9, with the presence of bacteria belonging to Clostridium sp., Bacillus sp., and Geobacillus sp. Together, our results indicate that BMC-9 has a strong ability to rapidly degrade the lignocelluloses of rice straw under relatively inexpensive conditions, and the optimum fermentation time is 9 days.

  7. Activation of Short and Long Chain Fatty Acid Sensing Machinery in the Ileum Lowers Glucose Production in Vivo.

    PubMed

    Zadeh-Tahmasebi, Melika; Duca, Frank A; Rasmussen, Brittany A; Bauer, Paige V; Côté, Clémence D; Filippi, Beatrice M; Lam, Tony K T

    2016-04-15

    Evidence continues to emerge detailing the myriad of ways the gut microbiota influences host energy homeostasis. Among the potential mechanisms, short chain fatty acids (SCFAs), the byproducts of microbial fermentation of dietary fibers, exhibit correlative beneficial metabolic effects in humans and rodents, including improvements in glucose homeostasis. The underlying mechanisms, however, remain elusive. We here report that one of the main bacterially produced SCFAs, propionate, activates ileal mucosal free fatty acid receptor 2 to trigger a negative feedback pathway to lower hepatic glucose production in healthy rats in vivo We further demonstrate that an ileal glucagon-like peptide-1 receptor-dependent neuronal network is necessary for ileal propionate and long chain fatty acid sensing to regulate glucose homeostasis. These findings highlight the potential to manipulate fatty acid sensing machinery in the ileum to regulate glucose homeostasis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Improving aerobic stability and biogas production of maize silage using silage additives.

    PubMed

    Herrmann, Christiane; Idler, Christine; Heiermann, Monika

    2015-12-01

    The effects of air stress during storage, exposure to air at feed-out, and treatment with silage additives to enhance aerobic stability on methane production from maize silage were investigated at laboratory scale. Up to 17% of the methane potential of maize without additive was lost during seven days exposure to air on feed-out. Air stress during storage reduced aerobic stability and further increased methane losses. A chemical additive containing salts of benzoate and propionate, and inoculants containing heterofermentative lactic acid bacteria were effective to increase aerobic stability and resulted in up to 29% higher methane yields after exposure to air. Exclusion of air to the best possible extent and high aerobic stabilities should be primary objectives when ensiling biogas feedstocks. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Blood-brain barrier transport of the alpha-keto acid analogs of amino acids.

    PubMed

    Steele, R D

    1986-06-01

    A number of alpha-keto acid analogs of amino acids have been found to penetrate the blood-brain barrier (BBB). Pyruvate, alpha-ketobutyrate, alpha-ketoisocaproate, and alpha-keto-gamma-methiolbutyrate all cross the BBB by a carrier-mediated process and by simple diffusion. Under normal physiological conditions, diffusion accounts for roughly 15% or less of total transport. Aromatic alpha-keto acids, phenylpyruvate, and p-hydroxyphenylpyruvate do not penetrate the BBB, nor do they inhibit the transport of other alpha-keto acids. Evidence based primarily on inhibition studies indicates that the carrier-mediated transport of alpha-keto acids occurs via the same carrier demonstrated previously for propionate, acetoacetate, and beta-hydroxybutyrate transport, commonly referred to as the monocarboxylate carrier. As a group, the alpha-keto acid analogs of the amino acids have the highest affinity for the carrier, followed by propionate and beta-hydroxybutyrate. Starvation for 4 days induces transport of alpha-keto acids, but transport is suppressed in rats fed commercial laboratory rations and subjected to portacaval shunts. The mitochondrial pyruvate translocator inhibitor alpha-cyanocinnamate has no effect on the BBB transport of alpha-keto acids.

  10. EPS production by Propionibacterium freudenreichii facilitates its immobilization for propionic acid production.

    PubMed

    Belgrano, F D S; Verçoza, B R F; Rodrigues, J C F; Hatti-Kaul, R; Pereira, N

    2018-04-28

    Immobilization of microbial cells is a useful strategy for developing high cell density bioreactors with improved stability and productivity for production of different chemicals. Functionalization of the immobilization matrix or biofilm forming property of some strains has been utilized for achieving cell attachment. The aim of the present study was to investigate the production of exopolysaccharide (EPS) by Propionibacterium freudenreichii C.I.P 59.32 and utilize this feature for immobilization of the cells on porous glass beads for production of propionic acid. Propionibacterium freudenreichii was shown to produce both capsular and excreted EPS during batch cultivations using glucose as carbon source. Different electron microscopy techniques confirmed the secretion of EPS and formation of cellular aggregates. The excreted EPS was mainly composed of mannose and glucose in a 5·3 : 1 g g -1 ratio. Immobilization of the cells on untreated and polyethyleneimine (PEI)-treated Poraver beads in a bioreactor was evaluated. Higher productivity and yield of propionic acid (0·566 g l -1  h -1 and 0·314 g g -1 , respectively) was achieved using cells immobilized to untreated beads and EPS production reached 617·5 mg l -1 after 48 h. These results suggest an important role of EPS-producing strains for improving cell immobilization and propionic acid production. This study demonstrates the EPS-producing microbe to be easily immobilized on a solid matrix and to be used in a bioprocess. Such a system could be optimized for achieving high cell density in fermentations without the need for functionalization of the matrix. © 2018 The Society for Applied Microbiology.

  11. Co-digestion of wheat and rye bread suspensions with source-sorted municipal biowaste.

    PubMed

    Li, Chaoran; Mörtelmaier, Christoph; Winter, Josef; Gallert, Claudia

    2015-06-01

    Acidification of wheat bread (WBS), rye bread (RBS) and fresh biowaste suspensions (FBS), leading to lactate+acetate, lactate+acetate+n-buyrate, and acetate+propionate+n-butyrate, respectively, and biogas production as well as population dynamics were investigated. Co-fermentation of FBS (14 kg m(-3) d(-1) organic loading rate (OLR)) with WBS or RBS was stable up to an OLR of 22 kg m(-3) d(-1) and resulted in up to 3 times as much biogas. During co-fermentation at more than 20 kg m(-3) d(-1) OLR the total population increased more than 2-fold, but the originally low share of propionate-oxidizing bacteria significantly decreased. The proportion of methanogens also decreased. Whereas the proportion of Methanosarcinales to Methanomicrobiales in biowaste and biowaste+WBS remained constant, Methanosarcinales and in particular Methanosaeta spec. in the biowaste+RBS assay almost completely disappeared. Methanomicrobiales increased instead, indicating propionate oxidation via acetate cleavage to CO2 and hydrogen. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. 21 CFR 133.149 - Gruyere cheese.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... subjected to the action of lactic acid-producing and propionic acid-producing bacterial cultures. One or... packages. (c) Nomenclature. The name of the food is “gruyere cheese”. (d) Label declaration. Each of the...

  13. 21 CFR 133.149 - Gruyere cheese.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... subjected to the action of lactic acid-producing and propionic acid-producing bacterial cultures. One or... packages. (c) Nomenclature. The name of the food is “gruyere cheese”. (d) Label declaration. Each of the...

  14. 21 CFR 133.149 - Gruyere cheese.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... subjected to the action of lactic acid-producing and propionic acid-producing bacterial cultures. One or... packages. (c) Nomenclature. The name of the food is “gruyere cheese”. (d) Label declaration. Each of the...

  15. Effects of Dietary Forage and Calf Starter Diet on Ruminal pH and Bacteria in Holstein Calves during Weaning Transition

    PubMed Central

    Kim, Yo-Han; Nagata, Rie; Ohtani, Natsuki; Ichijo, Toshihiro; Ikuta, Kentaro; Sato, Shigeru

    2016-01-01

    We investigated the relationship between ruminal pH and bacteria in calves fed calf starter with and without forage during weaning transition. First, 16 Holstein bull calves were obtained from dairy farms and equipped with rumen cannulas by cannulation surgery. Then, calves (73.5 ± 4.2 kg; mean ± SE) were assigned to groups fed calf starter either with forage (HAY, n = 8) or without forage (CON, n = 8), and all calves were weaned at 8 weeks of age. Ruminal pH was measured continuously, and rumen fluid samples were collected at 7, 8, 9, and 11 weeks of age, namely −1, 0, 1, and 3 weeks after weaning, respectively, to assess volatile fatty acid concentrations and bacterial DNA. The 24-h mean ruminal pH was significantly (P < 0.05) different between the two groups. Diurnal changes in the 1-h mean ruminal pH were observed throughout the study in the HAY group; however, they were not observed at 0 and 1 weeks after weaning in the CON group. Moreover, the HAY group had significantly (P < 0.05) higher proportions of acetate and butyrate and lower proportion of propionate, and significantly (P < 0.05) lower ruminal acetate-to-propionate ratios were observed in the CON group. The ruminal bacterial diversity indices decreased after −1 week in both groups and increased at 0 and 1 weeks after weaning in the HAY and CON groups, respectively. From the 454 pyrosequencing analysis, significant differences (P < 0.05) were observed in the relative abundance of several phyla (Bacteroidetes, Actinobacteria, and Tenericutes) and one genus (Prevotella) between the two groups. From quantitative real-time PCR analysis, the HAY group had the higher copy numbers of cellulolytic bacteria (Ruminococcus flavefaciens and Ruminococcus albus) compared with the CON group. This study demonstrated that feeding of dietary forage alleviates subacute ruminal acidosis due to diurnal changes in ruminal pH. Furthermore, changes in ruminal pH affect the ruminal bacterial diversity and relative abundance, and these changes might have influenced the establishment of fermentative ruminal functions during weaning transition. PMID:27818645

  16. The Radical SAM enzyme NirJ catalyzes the removal of two propionate side chains during heme d1 biosynthesis.

    PubMed

    Boss, Linda; Oehme, Ramona; Billig, Susan; Birkemeyer, Claudia; Layer, Gunhild

    2017-12-01

    Heme d 1 is a modified tetrapyrrole playing an important role in denitrification by acting as the catalytically essential cofactor in the cytochrome cd 1 nitrite reductase of many denitrifying bacteria. In the course of heme d 1 biosynthesis, the two propionate side chains on pyrrole rings A and B of the intermediate 12,18-didecarboxysiroheme are removed from the tetrapyrrole macrocycle. In the final heme d 1 molecule, the propionate groups are replaced by two keto functions. Although it was speculated that the Radical S-adenosyl-l-methionine (SAM) enzyme NirJ might be responsible for the removal of the propionate groups and introduction of the keto functions, this has not been shown experimentally, so far. Here, we demonstrate that NirJ is a Radical SAM enzyme carrying two iron-sulfur clusters. While the N-terminal [4Fe-4S] cluster is essential for the initial SAM cleavage reaction, it is not required for substrate binding. NirJ tightly binds its substrate 12,18-didecarboxysiroheme and, thus, can be purified in complex with the substrate. By using the purified NirJ/substrate complex in an in vitro enzyme activity assay, we show that NirJ indeed catalyzes the removal of the two propionate side chains under simultaneous SAM cleavage. However, under the reaction conditions employed, no keto group formation is observed indicating that an additional cofactor or enzyme is needed for this reaction. © 2017 Federation of European Biochemical Societies.

  17. 21 CFR 133.195 - Swiss and emmentaler cheese.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... treated with hydrogen peroxide/catalase, and is subjected to the action of lactic acid-producing and propionic acid-producing bacterial cultures. One or more of the clotting enzymes specified in paragraph (b... firm. The acidity of the whey at this point, calculated as lactic acid, does not exceed 0.13 percent...

  18. 21 CFR 133.195 - Swiss and emmentaler cheese.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... treated with hydrogen peroxide/catalase, and is subjected to the action of lactic acid-producing and propionic acid-producing bacterial cultures. One or more of the clotting enzymes specified in paragraph (b... firm. The acidity of the whey at this point, calculated as lactic acid, does not exceed 0.13 percent...

  19. 21 CFR 133.195 - Swiss and emmentaler cheese.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... treated with hydrogen peroxide/catalase, and is subjected to the action of lactic acid-producing and propionic acid-producing bacterial cultures. One or more of the clotting enzymes specified in paragraph (b... firm. The acidity of the whey at this point, calculated as lactic acid, does not exceed 0.13 percent...

  20. Biobased methacrylic acid via selective catalytic decarboxylation of itaconic acid

    USDA-ARS?s Scientific Manuscript database

    We report a bio-based route to methacrylic acid via selective decarboxylation of itaconic acid utilizing catalytic ruthenium carbonyl propionate in an aqueous solvent system. High selectivity (>90%) was achieved at low catalyst loading (0.1 mol %) with high substrate concentration (5.5 M) at low tem...

  1. Competition and coexistence of sulfate-reducing bacteria, acetogens and methanogens in a lab-scale anaerobic bioreactor as affected by changing substrate to sulfate ratio

    PubMed Central

    Dar, Shabir A.; Kleerebezem, Robbert; Stams, Alfons J. M.; Kuenen, J. Gijs

    2008-01-01

    The microbial population structure and function of natural anaerobic communities maintained in lab-scale continuously stirred tank reactors at different lactate to sulfate ratios and in the absence of sulfate were analyzed using an integrated approach of molecular techniques and chemical analysis. The population structure, determined by denaturing gradient gel electrophoresis and by the use of oligonucleotide probes, was linked to the functional changes in the reactors. At the influent lactate to sulfate molar ratio of 0.35 mol mol−1, i.e., electron donor limitation, lactate oxidation was mainly carried out by incompletely oxidizing sulfate-reducing bacteria, which formed 80–85% of the total bacterial population. Desulfomicrobium- and Desulfovibrio-like species were the most abundant sulfate-reducing bacteria. Acetogens and methanogenic Archaea were mostly outcompeted, although less than 2% of an acetogenic population could still be observed at this limiting concentration of lactate. In the near absence of sulfate (i.e., at very high lactate/sulfate ratio), acetogens and methanogenic Archaea were the dominant microbial communities. Acetogenic bacteria represented by Dendrosporobacter quercicolus-like species formed more than 70% of the population, while methanogenic bacteria related to uncultured Archaea comprising about 10–15% of the microbial community. At an influent lactate to sulfate molar ratio of 2 mol mol−1, i.e., under sulfate-limiting conditions, a different metabolic route was followed by the mixed anaerobic community. Apparently, lactate was fermented to acetate and propionate, while the majority of sulfidogenesis and methanogenesis were dependent on these fermentation products. This was consistent with the presence of significant levels (40–45% of total bacteria) of D. quercicolus-like heteroacetogens and a corresponding increase of propionate-oxidizing Desulfobulbus-like sulfate-reducing bacteria (20% of the total bacteria). Methanogenic Archaea accounted for 10% of the total microbial community. PMID:18305937

  2. Simple physics-based analytical formulas for the potentials of mean force of the interaction of amino-acid side chains in water. V. Like-charged side chains.

    PubMed

    Makowski, Mariusz; Liwo, Adam; Sobolewski, Emil; Scheraga, Harold A

    2011-05-19

    A new model of side-chain-side-chain interactions for charged side-chains of amino acids, to be used in the UNRES force-field, has been developed, in which a side chain consists of a nonpolar and a charged site. The interaction energy between the nonpolar sites is composed of a Gay-Berne and a cavity term; the interaction energy between the charged sites consists of a Lennard-Jones term, a Coulombic term, a generalized-Born term, and a cavity term, while the interaction energy between the nonpolar and charged sites is composed of a Gay-Berne and a polarization term. We parametrized the energy function for the models of all six pairs of natural like-charged amino-acid side chains, namely propionate-propionate (for the aspartic acid-aspartic acid pair), butyrate-butyrate (for the glutamic acid-glutamic acid pair), propionate-butyrate (for the aspartic acid-glutamic acid pair), pentylamine cation-pentylamine cation (for the lysine-lysine pair), 1-butylguanidine cation-1-butylguanidine cation (for the arginine-arginine pair), and pentylamine cation-1-butylguanidine cation (for the lysine-arginine pair). By using umbrella-sampling molecular dynamics simulations in explicit TIP3P water, we determined the potentials of mean force of the above-mentioned pairs as functions of distance and orientation and fitted analytical expressions to them. The positions and depths of the contact minima and the positions and heights of the desolvation maxima, including their dependence on the orientation of the molecules were well represented by analytical expressions for all systems. The values of the parameters of all the energy components are physically reasonable, which justifies use of such potentials in coarse-grain protein-folding simulations. © 2011 American Chemical Society

  3. Comparing the effects of different dietary organic acids on the growth, intestinal short-chain fatty acids, and liver histopathology of red hybrid tilapia (Oreochromis sp.) and potential use of these as preservatives.

    PubMed

    Ebrahimi, Mahdi; Daeman, Nor Hafizah; Chong, Chou Min; Karami, Ali; Kumar, Vikas; Hoseinifar, Seyed Hossein; Romano, Nicholas

    2017-08-01

    Dietary organic acids are increasingly being investigated as a potential means of improving growth and nutrient utilization in aquatic animals. A 9-week study was performed to compare equal amounts (2%) of different organic acids (sodium butyrate, acetate, propionate, or formate) on the growth, muscle proximate composition, fatty acid composition, cholesterol and lipid peroxidation, differential cell counts, plasma biochemistry, intestinal short-chain fatty acid (SCFA) level, and liver histopathology to red hybrid tilapia (Oreochromis sp.) (initial mean weight of 2.87 g). A second experiment was performed to determine their effects on lipid peroxidation and trimethylamine (TMA) when added at 1% to tilapia meat and left out for 24 h. The results of the first experiment showed no treatment effect to growth, feeding efficiencies, or muscle fatty acid composition, but all dietary organic acids significantly decreased intestinal SCFA. Dietary butyrate and propionate significantly decreased muscle lipid peroxidation compared to the control group, but the dietary formate treatment had the lowest lipid peroxidation compared to all treatments. Muscle crude protein and lipid in tilapia fed the formate diet were significantly lower and higher, respectively, and showed evidence of stress based on the differential cell counts, significantly higher plasma glucose and liver glycogen, as well as inflammatory responses in the liver. Although a potential benefit of dietary organic acids was a reduction to lipid peroxidation, this could be accomplished post-harvest by direct additions to the meat. In addition, inclusions of butyrate and propionate to tilapia meat significantly decreased TMA, which might be a more cost-effective option to improve the shelf life of tilapia products.

  4. Effect of different levels of concentrate on ruminal microorganisms and rumen fermentation in Nellore steers.

    PubMed

    Granja-Salcedo, Yury T; Ribeiro Júnior, Carlos S; de Jesus, Raphael B; Gomez-Insuasti, Arturo S; Rivera, Astrid R; Messana, Juliana D; Canesin, Roberta C; Berchielli, Telma T

    2016-01-01

    The aim of this study was to investigate the effect of different dietary levels of concentrate on feed intake, digestibility, ruminal fermentation and microbial population in steers. Eight Nellore steers fitted with ruminal cannulas were used in a double 4 × 4 Latin square design experiment. The dietary treatments consist of four different proportions of concentrate to roughage: 30:70, 40:60, 60:40 and 80:20% in the dry matter, resulting in Diets 30, 40, 60 and 80, respectively. The roughage was corn silage, and the concentrate was composed of corn, soybean meal and urea. Apparent digestibility of organic matter and crude protein showed a linear association with concentrate proportion (p = 0.01), but the increased concentrate levels did not affect the digestibility of fibre. The lowest ruminal pH-values were observed in animals fed with Diet 80, remaining below pH 6.0 from 6 h after feeding, while in the other diets, the ruminal pH was below 6.0 not before 12 h after feeding. After feeding Diet 80, the ammonia concentration in the rumen was significantly the highest. Higher dietary concentrate levels resulted in a linear increase of propionic acid concentrations, a linear reduction of the ratio acetic acid to propionic acid (p < 0.01) and a linear increased synthesis of microbial nitrogen (p < 0.001). The predicted production of methane was lower in diets with greater amounts of concentrate (p = 0.032). The population of methanogens, R. flavefaciens and R. albus decreased with higher concentrate levels, while the population of S. ruminantium increased (p < 0.05). The results indicate that greater amounts of concentrate do not decrease ruminal pH-values as much as expected and inhibit some cellulolytic bacteria without impairing the dry matter intake and fibre digestibility in Nellore steers.

  5. Selected biomarkers as predictive tools in testing efficacy of melatonin and coenzyme Q on propionic acid - induced neurotoxicity in rodent model of autism.

    PubMed

    Al-Ghamdi, Mashael; Al-Ayadhi, Laila; El-Ansary, Afaf

    2014-02-25

    Exposures to environmental toxins are now thought to contribute to the development of autism spectrum disorder. Propionic acid (PA) found as a metabolic product of gut bacteria has been reported to mimic/mediate the neurotoxic effects of autism. Results from animal studies may guide investigations on human populations toward identifying environmental contaminants that produce or drugs that protect from neurotoxicity. Forty-eight young male Western Albino rats were used in the present study. They were grouped into six equal groups 8 rats each. The first group received a neurotoxic dose of buffered PA (250 mg/Kg body weight/day for 3 consecutive days). The second group received only phosphate buffered saline (control group). The third and fourth groups were intoxicated with PA as described above followed by treatment with either coenzyme Q (4.5 mg/kg body weight) or melatonin (10 mg/kg body weight) for one week (therapeutically treated groups). The fifth and sixth groups were administered both compounds for one week prior to PA (protected groups). Heat shock protein70 (Hsp70), Gamma amino-butyric acid (GABA), serotonin, dopamine, oxytocin and interferon γ-inducible protein 16 together with Comet DNA assay were measured in brain tissues of the six studied groups. The obtained data showed that PA caused multiple signs of brain toxicity revealed in depletion of GABA, serotonin, and dopamine, are which important neurotransmitters that reflect brain function, interferon γ-inducible protein 16 and oxytocin. A high significant increase in tail length, tail DNA% damage and tail moment was reported indicating the genotoxic effect of PA. Administration of melatonin or coenzyme Q showed both protective and therapeutic effects on PA-treated rats demonstrated in a remarkable amelioration of most of the measured parameters. In conclusion, melatonin and coenzyme Q have potential protective and restorative effects against PA-induced brain injury, confirmed by improvement in biochemical markers and DNA double strand breaks.

  6. Selected biomarkers as predictive tools in testing efficacy of melatonin and coenzyme Q on propionic acid - induced neurotoxicity in rodent model of autism

    PubMed Central

    2014-01-01

    Background Exposures to environmental toxins are now thought to contribute to the development of autism spectrum disorder. Propionic acid (PA) found as a metabolic product of gut bacteria has been reported to mimic/mediate the neurotoxic effects of autism. Results from animal studies may guide investigations on human populations toward identifying environmental contaminants that produce or drugs that protect from neurotoxicity. Forty-eight young male Western Albino rats were used in the present study. They were grouped into six equal groups 8 rats each. The first group received a neurotoxic dose of buffered PA (250 mg/Kg body weight/day for 3 consecutive days). The second group received only phosphate buffered saline (control group). The third and fourth groups were intoxicated with PA as described above followed by treatment with either coenzyme Q (4.5 mg/kg body weight) or melatonin (10 mg/kg body weight) for one week (therapeutically treated groups). The fifth and sixth groups were administered both compounds for one week prior to PA (protected groups). Heat shock protein70 (Hsp70), Gamma amino-butyric acid (GABA), serotonin, dopamine, oxytocin and interferon γ-inducible protein 16 together with Comet DNA assay were measured in brain tissues of the six studied groups. Results The obtained data showed that PA caused multiple signs of brain toxicity revealed in depletion of GABA, serotonin, and dopamine, are which important neurotransmitters that reflect brain function, interferon γ-inducible protein 16 and oxytocin. A high significant increase in tail length, tail DNA% damage and tail moment was reported indicating the genotoxic effect of PA. Administration of melatonin or coenzyme Q showed both protective and therapeutic effects on PA–treated rats demonstrated in a remarkable amelioration of most of the measured parameters. Conclusion In conclusion, melatonin and coenzyme Q have potential protective and restorative effects against PA-induced brain injury, confirmed by improvement in biochemical markers and DNA double strand breaks. PMID:24568717

  7. Co-cultivation of Lactobacillus zeae and Veillonella cricetifor the production of propionic acid

    PubMed Central

    2013-01-01

    In this work a defined co-culture of the lactic acid bacterium Lactobacillus zeae and the propionate producer Veillonella criceti has been studied in continuous stirred tank reactor (CSTR) and in a dialysis membrane reactor. It is the first time that this reactor type is used for a defined co-culture fermentation. This reactor allows high mixing rates and working with high cell densities, making it ideal for co-culture investigations. In CSTR experiments the co-culture showed over a broad concentration range an almost linear correlation in consumption and production rates to the supply with complex nutrients. In CSTR and dialysis cultures a strong growth stimulation of L. zeae by V. criceti was shown. In dialysis cultures very high propionate production rates (0.61 g L-1h-1) with final titers up to 28 g L-1 have been realized. This reactor allows an individual, intracellular investigation of the co-culture partners by omic-technologies to provide a better understanding of microbial communities. PMID:23705662

  8. Antibacterial properties of soap containing some fatty acid esters.

    PubMed

    Pandey, N K; Natraj, C V; Kalle, G P; Nambudiry, M E

    1985-02-01

    Synopsis Chemical microbial inhibitors compatible with formulations of soaps and deodorant perfumes are more effective if they are substantive to the skin. However, highly effective inhibitors are toxic and their substantivity on skin may accentuate the toxicity. Natural compounds such as short to medium chain fatty acids and their derivatives, which are known to be germicidal, offer a viable alternative to chemical inhibitors. We report here the synthesis of sodium 2-lauroyloxy propionate and an in vivo method to test its substantivity on skin following its incorporation in soaps. Among several compounds tested, sodium 2-lauroyloxy propionate was found to be highly substantive in soap formulation.

  9. Can the development and autolysis of lactic acid bacteria influence the cheese volatile fraction? The case of Grana Padano.

    PubMed

    Lazzi, Camilla; Povolo, Milena; Locci, Francesco; Bernini, Valentina; Neviani, Erasmo; Gatti, Monica

    2016-09-16

    In this study, the relationship between the dynamics of the growth and lysis of lactic acid bacteria in Grana Padano cheese and the formation of the volatile flavor compounds during cheese ripening was investigated. The microbial dynamics of Grana Padano cheeses that were produced in two different dairies were followed during ripening. The total and cultivable lactic microflora, community composition as determined by length heterogeneity-PCR (LH-PCR), and extent of bacterial lysis using an intracellular enzymatic activity assay were compared among cheeses after 2, 6 and 13months of ripening in two dairies. The evolution of whole and lysed microbiota was different between the two dairies. In dairy 2, the number of total cells was higher than that in dairy 1 in all samples, and the number of cells that lysed during ripening was lower. In addition, at the beginning of ripening (2months), the community structure of the cheese from dairy 2 was more complex and was composed of starter lactic acid bacteria (Lactobacillus helveticus and Lactobacillus delbrueckii) and NSLAB, possibly arising from raw milk, including Lactobacillus rhamnosus/Lactobacillus casei and Pediococcus acidilactici. On the other hand, the cheese from dairy 1 that ripened for 2months was mainly composed of the SLAB L. helveticus and L. delbrueckii. An evaluation of the free-DNA fraction through LH-PCR identified those species that had a high degree of lysis. Data on the dynamics of bacterial growth and lysis were evaluated with respect to the volatile profile and the organic acid content of the two cheeses after 13months of ripening, producing very different results. Cheese from dairy 1 showed a higher content of free fatty acids, particularly those deriving from milk fat lipolysis, benzaldehyde and organic acids, such as pGlu and citric. In contrast, cheese from dairy 2 had a greater amount of ketones, alcohols, hydrocarbons, acetic acid and propionic acid. Based on these results, we can conclude that in the first cheese, the intracellular enzymes that were released from lysis were mainly involved in aroma formation, whereas in the second cheese, the greater complexity of volatile compounds may be associated with its more complex microbial composition caused from SLAB lysis and NSLAB (mainly L. rhamnosus/L. casei) growth during ripening. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. 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

  11. Short-chain fatty acid fermentation products of the gut microbiome: implications in autism spectrum disorders

    PubMed Central

    MacFabe, Derrick F.

    2012-01-01

    Recent evidence suggests potential, but unproven, links between dietary, metabolic, infective, and gastrointestinal factors and the behavioral exacerbations and remissions of autism spectrum disorders (ASDs). Propionic acid (PPA) and its related short-chain fatty acids (SCFAs) are fermentation products of ASD-associated bacteria (Clostridia, Bacteriodetes, Desulfovibrio). SCFAs represent a group of compounds derived from the host microbiome that are plausibly linked to ASDs and can induce widespread effects on gut, brain, and behavior. Intraventricular administration of PPA and SCFAs in rats induces abnormal motor movements, repetitive interests, electrographic changes, cognitive deficits, perseveration, and impaired social interactions. The brain tissue of PPA-treated rats shows a number of ASD-linked neurochemical changes, including innate neuroinflammation, increased oxidative stress, glutathione depletion, and altered phospholipid/acylcarnitine profiles. These directly or indirectly contribute to acquired mitochondrial dysfunction via impairment in carnitine-dependent pathways, consistent with findings in patients with ASDs. Of note, common antibiotics may impair carnitine-dependent processes by altering gut flora favoring PPA-producing bacteria and by directly inhibiting carnitine transport across the gut. Human populations that are partial metabolizers of PPA are more common than previously thought. PPA has further bioactive effects on neurotransmitter systems, intracellular acidification/calcium release, fatty acid metabolism, gap junction gating, immune function, and alteration of gene expression that warrant further exploration. These findings are consistent with the symptoms and proposed underlying mechanisms of ASDs and support the use of PPA infusions in rats as a valid animal model of the condition. Collectively, this offers further support that gut-derived factors, such as dietary or enteric bacterially produced SCFAs, may be plausible environmental agents that can trigger ASDs or ASD-related behaviors and deserve further exploration in basic science, agriculture, and clinical medicine. PMID:23990817

  12. Influence of the organic loading rate on the performance and the granular sludge characteristics of an EGSB reactor used for treating traditional Chinese medicine wastewater.

    PubMed

    Li, Weiguang; Su, Chengyuan; Liu, Xingzhe; Zhang, Lei

    2014-01-01

    The effects of the organic loading rate (OLR) on the performance and the granular sludge characteristics of an expanded granular sludge bed (EGSB) reactor used for treating real traditional Chinese medicine (TCM) wastewater were investigated. Over 90% of the COD removal by the EGSB reactor was observed at the OLRs of 4 to 13 kg COD/(m(3) day). However, increasing the OLR to 20 kg COD/(m(3) day) by reducing the hydraulic retention time (HRT 6 h) reduced the COD removal efficiency to 78%. The volatile fatty acid (VFA) concentration was 512.22 mg/L, resulting in an accumulation of VFAs, and propionic acid was the main acidification product, accounting for 66.51% of the total VFAs. When the OLR increased from 10 to 20 kg COD/(m(3) day), the average size of the granule sludge decreased from 469 to 258 μm. There was an obvious reduction in the concentration of Ca(2+) and Mg(2+) in the granular sludge. The visible humic acid-like peak was identified in the three-dimensional excitation-emission matrix (EEM) fluorescence spectra of the soluble microbial products (SMPs). The fatty acid bond, amide II bond, amide III bond, and C-H bond bending were also observed in the Fourier transform infrared (FTIR) spectra of the SMPs. Methanobacterium formicicum, Methanococcus, and Bacteria populations exhibited significant shifts, and these changes were accompanied by an increase in VFA production. The results indicated that a short HRT and high OLR in the EGSB reactor caused the accumulation of polysaccharides, protein, and VFAs, thereby inhibiting the activity of methanogenic bacteria and causing granular sludge corruption.

  13. A multidisciplinary research program directed toward utilization of solar energy through bioconversion of renewable resources

    NASA Astrophysics Data System (ADS)

    Finnerty, W. R.

    1980-07-01

    Cellulytic bacteria, cellobiose fermentors, sulfate-reducing bacteria and methanogenic bacteria were isolated from established anaerobic mesophilic and thermophilic cellulose methane fermentations and these isolates, plus known laboratory strains, were employed to partially reconstitute highly active cellulose fermentations. These mixed cultures are utilized as model systems to study the parameters required for maximum production of CH4, H2 and chemical feedstocks such as acetate, ethanol, propionate, etc., from cellulose. The physiology of these reconstituted cultures is investigated as regards cultural conditions, microbial types, inoculum size, interspecies H2 transfer and specific regulatory phenomena, the accumulation of cellobiose and acetate.

  14. Use of organic acids to inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on organic fresh apples and lettuce.

    PubMed

    Park, Sang-Hyun; Choi, Mi-Ran; Park, Jeong-Woong; Park, Ki-Hwan; Chung, Myung-Sub; Ryu, Sangryeol; Kang, Dong-Hyun

    2011-08-01

    This study was undertaken to investigate the antimicrobial effect of organic acids against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on whole red organic apples and lettuce. Several studies have been conducted to evaluate organic acids as sanitizers. However, no studies have compared antimicrobial effects of various organic acids on organic fresh produce, including evaluation of color changes of produce. Apples and lettuce were inoculated with a cocktail of 3 strains each of 3 foodborne pathogens provided above and treated with 1% and 2% organic acids (propionic, acetic, lactic, malic, and citric acid) for 0, 0.5, 1, 5, and 10 min. With increasing treatment time and acid concentration, organic acid treatments showed significant reduction compared to the control treatment (distilled water), and differences in antimicrobial effects between organic acids were observed. After 10 min of treatment with 1% and 2% organic acids in apples, propionic (0.92 to 2.75 log reduction), acetic (0.52 to 2.78 log reduction), lactic (1.69 to >3.42 log reduction), malic (1.48 to >3.42 log reduction), and citric acid (1.52 to >3.42 log reduction) exhibited significant (P < 0.05) antibacterial effects against 3 foodborne pathogens compared to the control treatment. In lettuce, propionic (0.93 to 1.52 log reduction), acetic (1.13 to 1.74 log reduction), lactic (1.87 to 2.54 log reduction), malic (2.32 to 2.98 log reduction), and citric acid (1.85 to 2.86 log reduction) showed significant (P < 0.05) effects compared to the control treatment. Changes in sample color subjected to organic acids treatment were not significant during storage. It is suggested that organic acids have a potential as sanitizers for organic fresh produce. These data may help the organic produce industry provide safe fresh produce for consumers. © 2011 Institute of Food Technologists®

  15. Evaluation of support matrices for immobilization of anaerobic consortia for efficient carbon cycling in waste regeneration.

    PubMed

    Chauhan, Ashvini; Ogram, Andrew

    2005-02-18

    Efficient metabolism of fatty acids during anaerobic waste digestion requires development of consortia that include "fatty acid consuming H(2) producing bacteria" and methanogenic bacteria. The objective of this research was to optimize methanogenesis from fatty acids by evaluating a variety of support matrices for use in maintaining efficient syntrophic-methanogenic consortia. Tested matrices included clays (montmorillonite and bentonite), glass beads (106 and 425-600mum), microcarriers (cytopore, cytodex, cytoline, and cultispher; conventionally employed for cultivation of mammalian cell lines), BioSep beads (powdered activated carbon), and membranes (hydrophilic; nylon, polysulfone, and hydrophobic; teflon, polypropylene). Data obtained from headspace methane (CH(4)) analyses as an indicator of anaerobic carbon cycling efficiency indicated that material surface properties were important in maintenance and functioning of the anaerobic consortia. Cytoline yielded significantly higher CH(4) than other matrices as early as in the first week of incubation. 16S rRNA gene sequence analysis from crushed cytoline matrix showed the presence of Syntrophomonas spp. (butyrate oxidizing syntrophs) and Syntrophobacter spp. (propionate oxidizing syntrophs), with Methanosaeta spp. (acetate utilizing methanogen), and Methanospirillum spp. (hydrogen utilizing methanogen) cells. It is likely that the more hydrophobic surfaces provided a suitable surface for adherence of cells of syntrophic-methanogenic consortia. Cytoline also appeared to protect entrapped consortia from air, resulting in rapid methanogenesis after aerial exposure. Our study suggests that support matrices can be used in anaerobic digestors, pre-seeded with immobilized or entrapped consortia on support matrices, and may be of value as inoculant-adsorbents to rapidly initiate or recover proper system functioning following perturbation.

  16. Hops (Humulus lupulus L.) Bitter Acids: Modulation of Rumen Fermentation and Potential As an Alternative Growth Promoter

    PubMed Central

    Flythe, Michael D.; Kagan, Isabelle A.; Wang, Yuxi; Narvaez, Nelmy

    2017-01-01

    Antibiotics can improve ruminant growth and efficiency by altering rumen fermentation via selective inhibition of microorganisms. However, antibiotic use is increasingly restricted due to concerns about the spread of antibiotic-resistance. Plant-based antimicrobials are alternatives to antibiotics in animal production. The hops plant (Humulus lupulus L.) produces a range of bioactive secondary metabolites, including antimicrobial prenylated phloroglucinols, which are commonly called alpha- and beta-acids. These latter compounds can be considered phyto-ionophores, phytochemicals with a similar antimicrobial mechanism of action to ionophore antibiotics (e.g., monensin, lasalocid). Like ionophores, the hop beta-acids inhibit rumen bacteria possessing a classical Gram-positive cell envelope. This selective inhibition causes several effects on rumen fermentation that are beneficial to finishing cattle, such as decreased proteolysis, ammonia production, acetate: propionate ratio, and methane production. This article reviews the effects of hops and hop secondary metabolites on rumen fermentation, including the physiological mechanisms on specific rumen microorganisms, and consequences for the ruminant host and ruminant production. Further, we propose that hop beta-acids are useful model natural products for ruminants because of (1) the ionophore-like mechanism of action and spectrum of activity and (2) the literature available on the plant due to its use in brewing. PMID:28871284

  17. Activities of free and encapsulated Lactobacillus acidophilus LA5 or Lactobacillus casei 01 in processed longan juices on exposure to simulated gastrointestinal tract.

    PubMed

    Chaikham, Pittaya; Apichartsrangkoon, Arunee; Worametrachanon, Srivilai; Supraditareporn, Wissanee; Chokiatirote, Ekachai; Van der Wiele, Tom

    2013-07-01

    Fruit drinks containing probiotics are gaining interest in the global marketplace. For example, longan juice, containing carbohydrate and various bioactive components, is a potentially health-promoting beverage as well as probiotic carrier for human consumption. In this study, high-pressure and thermal processes were applied to eliminate competitive micro-organisms in longan juice prior to the addition of Lactobacillus acidophilus LA5 or Lactobacillus casei 01. The activities of these probiotics in a simulated gastrointestinal tract were also investigated. Encapsulated probiotics could survive in the acidic environment of the stomach and small intestine, while the free cells were completely eliminated. In the colon experiment, the influence of encapsulated L. casei 01 on colon lactobacilli was significantly greater than that of encapsulated L. acidophilus LA5. Both encapsulated probiotics suspended in processed longan juices led to extensive increases in the formation of lactic acid and short-chain fatty acids (SCFA). Acetate was the major SCFA produced by colon bacteria, followed by propionate and butyrate. The discernible clear zone suggested that L. casei 01 provided greater antibacterial activity than L. acidophilus LA5. Both encapsulated probiotics along with processed longan juice led to significant increases in colon lactobacilli, lactic acid and SCFA formation. © 2012 Society of Chemical Industry.

  18. Efficacy of fatty acid chemistry : candidate mold and decay fungicides

    Treesearch

    Robert Coleman; Vina Yang; Bessie Woodward; Patti Lebow; Carol Clausen

    2010-01-01

    Although organic, lipophilic acids, such as acetic, propionic, sorbic and benzoic, have a long history as preservatives in the food industry, relatively high concentrations are required and their bioactivities generally pertain to retarding microbial growth rather than eliminating pathogens. Moreover, exclusive use of organic acids such as lactic or citric acid, alone...

  19. Influence of dietary protein and fructooligosaccharides on fecal fermentative end-products, fecal bacterial populations and apparent total tract digestibility in dogs.

    PubMed

    Pinna, Carlo; Vecchiato, Carla Giuditta; Bolduan, Carmen; Grandi, Monica; Stefanelli, Claudio; Windisch, Wilhelm; Zaghini, Giuliano; Biagi, Giacomo

    2018-03-20

    Feeding dogs with diets rich in protein may favor putrefactive fermentations in the hindgut, negatively affecting the animal's intestinal environment. Conversely, prebiotics may improve the activity of health-promoting bacteria and prevent bacterial proteolysis in the colon. The aim of this study was to evaluate the effects of dietary supplementation with fructooligosaccharides (FOS) on fecal microbiota and apparent total tract digestibility (ATTD) in dogs fed kibbles differing in protein content. Twelve healthy adult dogs were used in a 4 × 4 replicated Latin Square design to determine the effects of four diets: 1) Low protein diet (LP, crude protein (CP) 229 g/kg dry matter (DM)); 2) High protein diet (HP, CP 304 g/kg DM); 3) Diet 1 + 1.5 g of FOS/kg; 4) Diet 2 + 1.5 g of FOS/kg. The diets contained silica at 5 g/kg as a digestion marker. Differences in protein content were obtained using different amounts of a highly digestible swine greaves meal. Each feeding period lasted 28 d, with a 12 d wash-out in between periods. Fecal samples were collected from dogs at 0, 21 and 28 d of each feeding period. Feces excreted during the last five days of each feeding period were collected and pooled in order to evaluate ATTD. Higher fecal ammonia concentrations were observed both when dogs received the HP diets (p < 0.001) and the supplementation with FOS (p < 0.05). The diets containing FOS resulted in greater ATTD of DM, Ca, Mg, Na, Zn, and Fe (p < 0.05) while HP diets were characterized by lower crude ash ATTD (p < 0.05). Significant interactions were observed between FOS and protein concentration in regards to fecal pH (p < 0.05), propionic acid (p < 0.05), acetic to propionic acid and acetic + n-butyric to propionic acid ratios (p < 0.01), bifidobacteria (p < 0.05) and ATTD of CP (p < 0.05) and Mn (p < 0.001). A relatively moderate increase of dietary protein resulted in higher concentrations of ammonia in canine feces. Fructooligosaccharides displayed beneficial counteracting effects (such as increased bifidobacteria) when supplemented in HP diets, compared to those observed in LP diets and, in general, improved the ATTD of several minerals.

  20. The potential synergistic behaviour of inter- and intra-genus probiotic combinations in the pattern and rate of short chain fatty acids formation during fibre fermentation.

    PubMed

    Fernando, Warnakulasuriya M A D B; Flint, Steve H; Ranaweera, K K D S; Bamunuarachchi, Arthur; Johnson, Stuart K; Brennan, Charles S

    2018-03-01

    This study compared the rate of short chain fatty acid (SCFA) production by different probiotic combinations of Lactobacillus and Bifidobacterium to determine any synergistic effects. Six different fibre fractions were fermented with nine combinations of Lactobacillus rhamnosus (LR), Lactobacillus acidophilus (LA), Bifidobacterium longum (BL) and Bifidobacterium breve (BB) for 0, 6, 24 and 48 h. SCFAs were quantified by gas chromatography. Inter-genus combinations of bacteria produced more SCFA, especially BB + BL + LR, compared to intra-genus that yielded the lowest SCFA production. Acetate was the most abundant, while propionate and butyrate were the most utilised. The SCFA formation was as acetate > propionate > butyrate and the total dietary fibre produced most of the SCFA. Most combinations utilised 60-80% of the fibre; BB + BL + LR digested the fibre completely. The quantity, pattern and the time of release of SCFA depends on the genus, but the combination of pre and probiotics is of great importance for the outcome.

  1. Effect of using propionic acid bacteria as an adjunct culture in yogurt production.

    PubMed

    Ekinci, F Y; Gurel, M

    2008-03-01

    Propionibacteria are able to produce a wide variety of food components beneficial to human health. In this study, yogurt was produced by using the adjunct starter cultures Propionibacterium jensenii B1264 and Propionibacterium thoenii (jensenii) P126. Although the total solids and protein contents of the yogurts did not show any significant differences, titratable acidity of the control sample (YC-380) remained lower than that of Propionibacterium spp.-supplemented yogurts during 15 d of storage. The yogurts produced by YC-380 + P126 cultures had the firmest structure (0.26 N). The highest acetaldehyde (29.35 mg/kg) content was obtained with yogurt made with YC-380 + P126 + B1264 on d 1. The addition of propionibacteria to yogurt did not have any negative effect on the counts of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in yogurt. During the first week of storage, propionibacteria counts remained high, suggesting that yogurt provided a good environment for these organisms. This new product would provide not only beneficial health effects, but also a new alternative product to plain set-type yogurt.

  2. Investigation of the impact of trace elements on anaerobic volatile fatty acid degradation using a fractional factorial experimental design.

    PubMed

    Jiang, Ying; Zhang, Yue; Banks, Charles; Heaven, Sonia; Longhurst, Philip

    2017-11-15

    The requirement of trace elements (TE) in anaerobic digestion process is widely documented. However, little is understood regarding the specific requirement of elements and their critical concentrations under different operating conditions such as substrate characterisation and temperature. In this study, a flask batch trial using fractional factorial design is conducted to investigate volatile fatty acids (VFA) anaerobic degradation rate under the influence of the individual and combined effect of six TEs (Co, Ni, Mo, Se, Fe and W). The experiment inoculated with food waste digestate, spiked with sodium acetate and sodium propionate both to 10 g/l. This is followed by the addition of a selection of the six elements in accordance with a 2 6-2 fractional factorial principle. The experiment is conducted in duplicate and the degradation of VFA is regularly monitored. Factorial effect analysis on the experimental results reveals that within these experimental conditions, Se has a key role in promoting the degradation rates of both acetic and propionic acids; Mo and Co are found to have a modest effect on increasing propionic acid degradation rate. It is also revealed that Ni shows some inhibitory effects on VFA degradation, possibly due to its toxicity. Additionally, regression coefficients for the main and second order effects are calculated to establish regression models for VFA degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of Sunflower and Marine Oils on Ruminal Microbiota, In vitro Fermentation and Digesta Fatty Acid Profile

    PubMed Central

    Vargas, Julio E.; Andrés, Sonia; Snelling, Timothy J.; López-Ferreras, Lorena; Yáñez-Ruíz, David R.; García-Estrada, Carlos; López, Secundino

    2017-01-01

    This study using the rumen simulation technique (RUSITEC) investigated the changes in the ruminal microbiota and anaerobic fermentation in response to the addition of different lipid supplements to a ruminant diet. A basal diet with no oil added was the control, and the treatment diets were supplemented with sunflower oil (2%) only, or sunflower oil (2%) in combination with fish oil (1%) or algae oil (1%). Four fermentation units were used per treatment. RUSITEC fermenters were inoculated with rumen digesta. Substrate degradation, fermentation end-products (volatile fatty acids, lactate, gas, methane, and ammonia), and microbial protein synthesis were determined. Fatty acid profiles and microbial community composition were evaluated in digesta samples. Numbers of representative bacterial species and microbial groups were determined using qPCR. Microbial composition and diversity were based on T-RFLP spectra. The addition of oils had no effect on substrate degradation or microbial protein synthesis. Differences among diets in neutral detergent fiber degradation were not significant (P = 0.132), but the contrast comparing oil–supplemented diets with the control was significant (P = 0.039). Methane production was reduced (P < 0.05) with all oil supplements. Propionate production was increased when diets containing oil were fermented. Compared with the control, the addition of algae oil decreased the percentage C18:3 c9c12c15 in rumen digesta, and that of C18:2 c9t11 was increased when the control diet was supplemented with any oil. Marine oils decreased the hydrogenation of C18 unsaturated fatty acids. Microbial diversity was not affected by oil supplementation. Cluster analysis showed that diets with additional fish or algae oils formed a group separated from the sunflower oil diet. Supplementation with marine oils decreased the numbers of Butyrivibrio producers of stearic acid, and affected the numbers of protozoa, methanogens, Selenomonas ruminantium and Streptococcus bovis, but not total bacteria. In conclusion, there is a potential to manipulate the rumen fermentation and microbiota with the addition of sunflower, fish or algae oils to ruminant diets at appropriate concentrations. Specifically, supplementation of ruminant mixed rations with marine oils will reduce methane production, the acetate to propionate ratio and the fatty acid hydrogenation in the rumen. PMID:28676798

  4. Characteristics of Rare or Recently Described Corynebacterium Species Recovered from Human Clinical Material in Canada

    PubMed Central

    Bernard, K. A.; Munro, C.; Wiebe, D.; Ongsansoy, E.

    2002-01-01

    Nineteen new Corynebacterium species or taxa described since 1995 have been associated with human disease. We report the characteristics of 72 strains identified as or most closely resembling 14 of these newer, medically relevant Corynebacterium species or taxa, as well as describe in brief an isolate of Corynebacterium bovis, a rare pathogen for humans. The bacteria studied in this report were nearly all derived from human clinical specimens and were identified by a polyphasic approach. Most were characterized by nearly full 16S rRNA gene sequence analysis. Some isolates were recovered from previously unreported sources and exhibited unusual phenotypes or represented the first isolates found outside Europe. Products of fermentation, with emphasis on the presence or absence of propionic acid, were also studied in order to provide an additional characteristic with which to differentiate among phenotypically similar species. PMID:12409436

  5. Effects of dissolved low molecular weight organic acids on oxidation of ferrous iron by Acidithiobacillus ferrooxidans.

    PubMed

    Ren, Wan-Xia; Li, Pei-Jun; Zheng, Le; Fan, Shu-Xiu; Verhozina, V A

    2009-02-15

    A few researchers have reported on work concerning bioleaching of heavy-metal-contaminated soil using Acidithiobacillus ferrooxidans, since this acidophile is sensitive to dissolved low molecular weight (LMW) organic acids. Iron oxidation by A. ferrooxidans R2 as well as growth on ferrous iron was inhibited by a variety of dissolved LMW organic acids. Growth experiments with ferrous iron as an oxidant showed that the inhibition capability sequence was formic acid>acetic acid>propionic acid>oxalic acid>malic acid>citric acid. The concentrations that R2 might tolerate were formic acid 0.1mmolL(-1) (2mmolkg(-1)soil), acetic and propionic acids 0.4mmolL(-1) (8mmolkg(-1)soil), oxalic acid 2.0mmolL(-1) (40mmolkg(-1)soil), malic acid 20mmolL(-1) (400mmolkg(-1)soil), citric acid 40mmolL(-1) (800mmolkg(-1)soil), respectively. Although R2 was sensitive to organic acids, the concentrations of LMW organic acids in the contaminated soils were rather lower than the tolerable levels. Hence, it is feasible that R2 might be used for bioleaching of soils contaminated with metals or metals coupled with organic compounds because of the higher concentrations of LMW organic acids to which R2 is tolerant.

  6. In vitro fermentation pattern of D-tagatose is affected by adaptation of the microbiota from the gastrointestinal tract of pigs.

    PubMed

    Laerke, H N; Jensen, B B; Højsgaard, S

    2000-07-01

    Knowledge of the fermentation pattern of D-tagatose is important for the assessment of energy value and compliance of D-tagatose. In vitro fermentation experiments with pig intestinal contents and bacteria harvested from the gastrointestinal tract of pigs were used to investigate the degradation of D-tagatose and the formation of fermentation products. Two groups of eight pigs were fed either a control diet containing 150 g/kg sucrose or a diet which had 100 g/kg of the sucrose replaced by D-tagatose. After 18 d the pigs were killed and the gastrointestinal contents collected for in vitro studies. No microbial fermentation of D-tagatose occurred in the stomach or in the small intestine, whereas the sugar was fermented in the cecum and colon. Formate, acetate, propionate, butyrate, valerate, caproate and some heptanoate were produced by the microbial fermentation of D-tagatose by gut microbiota. Hydrogen and methane were also produced. The population of D-tagatose-degrading bacteria in fecal samples and the capacity of bacteria from the hindgut to degrade D-tagatose were higher in the pigs adapted to D-tagatose compared with unadapted pigs. In unadapted pigs, the major fermentation product from D-tagatose was acetic acid. Much more butyric and valeric acids were produced from D-tagatose by bacterial slurries of tagatose-adapted pigs compared with unadapted pigs; this was especially the case for samples from the colon. We conclude that D-tagatose is not fermented in the upper gastrointestinal tract, and the ability of the large intestinal microbiota to ferment D-tagatose is dependent on adaptation.

  7. Matrix-elimination with steam distillation for determination of short-chain fatty acids in hypersaline waters from pre-salt layer by ion-exclusion chromatography.

    PubMed

    Ferreira, Fernanda N; Carneiro, Manuel C; Vaitsman, Delmo S; Pontes, Fernanda V M; Monteiro, Maria Inês C; Silva, Lílian Irene D da; Neto, Arnaldo Alcover

    2012-02-03

    A method for determination of formic, acetic, propionic and butyric acids in hypersaline waters by ion-exclusion chromatography (IEC), using steam distillation to eliminate matrix-interference, was developed. The steam distillation variables such as type of solution to collect the distillate, distillation time and volume of the 50% v/v H₂SO₄ solution were optimized. The effect of the addition of NaCl different concentrations to the calibration standards on the carboxylic acid recovery was also investigated. Detection limits of 0.2, 0.5, 0.3 and 1.5 mg L⁻¹ were obtained for formic, acetic, propionic and butyric acids, respectively. Produced waters from petroleum reservoirs in the Brazilian pre-salt layer containing about 19% m/v of NaCl were analyzed. Good recoveries (99-108%) were obtained for all acids in spiked produced water samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Lipid metabolism in response to individual short chain fatty acids during mixotrophic mode of microalgal cultivation: Influence on biodiesel saturation and protein profile.

    PubMed

    Chandra, Rashmi; Arora, Somya; Rohit, M V; Venkata Mohan, S

    2015-01-01

    Critical influence of different short chain fatty acids as organic carbon source, during growth (GP) and nutrient stress lipogenic phase (NSLP) was investigated on biomass and lipid productivity, in mixotrophic fed-batch microalgae cultivation. Nutrient deprivation induced physiological stress stimulated highest lipid productivity with acetate (total/neutral lipids, 35/17) with saturation index of 80.53% by the end of NSLP followed by butyrate (12/7%; 78%). Biomass growth followed the order of acetate (2.23 g/l) >butyrate (0.99 g/l) >propionate (0.77 g/l). VFA removal (as COD) was maximum with acetate (87%) followed by butyrate (55.09%) and propionate (10.60%). Palmitic acid was the most dominant fatty acid found in the fatty acid composition of all variants and butyrate fed system yielded a maximum of 44% palmitic acid. Protein profiling illustrated prominence of acetyl CoA-synthetase activity in acetate system. Thus, fatty acids provide a promising alternative feedstock for biodiesel production with integrated microalgae-biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge.

    PubMed

    Ito, Tsukasa; Yoshiguchi, Kazumi; Ariesyady, Herto Dwi; Okabe, Satoshi

    2011-12-01

    Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope- and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with (14)C-acetate indicated the significant utilization of acetate by only two major groups, unidentified bacterial cells and Methanosaeta-like filamentous archaeal cells, in the digester sludge. To identify the acetate-utilizing unidentified bacteria, RNA-SIP was conducted with (13)C(6)-glucose and (13)C(3)-propionate as sole carbon source, which were followed by phylogenetic analysis of 16S rRNA. We found that bacteria belonging to Synergistes group 4 were commonly detected in both 16S rRNA clone libraries derived from the sludge incubated with (13)C-glucose and (13)C-propionate. To confirm that this bacterial group can utilize acetate, specific FISH probe targeting for Synergistes group 4 was newly designed and applied to the sludge incubated with (14)C-acetate for MAR-FISH. The MAR-FISH result showed that bacteria belonging to Synergistes group 4 significantly took up acetate and their active population size was comparable to that of Methanosaeta in this sludge. In addition, as bacteria belonging to Synergistes group 4 had high K(m) for acetate and maximum utilization rate, they are more competitive for acetate over Methanosaeta at high acetate concentrations (2.5-10  mM). To our knowledge, it is the first time to report the acetate-utilizing activity of uncultured bacteria belonging to Synergistes group 4 and its competitive significance to acetoclastic methanogen, Methanosaeta.

  10. Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge

    PubMed Central

    Ito, Tsukasa; Yoshiguchi, Kazumi; Ariesyady, Herto Dwi; Okabe, Satoshi

    2011-01-01

    Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope- and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with 14C-acetate indicated the significant utilization of acetate by only two major groups, unidentified bacterial cells and Methanosaeta-like filamentous archaeal cells, in the digester sludge. To identify the acetate-utilizing unidentified bacteria, RNA-SIP was conducted with 13C6-glucose and 13C3-propionate as sole carbon source, which were followed by phylogenetic analysis of 16S rRNA. We found that bacteria belonging to Synergistes group 4 were commonly detected in both 16S rRNA clone libraries derived from the sludge incubated with 13C-glucose and 13C-propionate. To confirm that this bacterial group can utilize acetate, specific FISH probe targeting for Synergistes group 4 was newly designed and applied to the sludge incubated with 14C-acetate for MAR-FISH. The MAR-FISH result showed that bacteria belonging to Synergistes group 4 significantly took up acetate and their active population size was comparable to that of Methanosaeta in this sludge. In addition, as bacteria belonging to Synergistes group 4 had high Km for acetate and maximum utilization rate, they are more competitive for acetate over Methanosaeta at high acetate concentrations (2.5–10 m). To our knowledge, it is the first time to report the acetate-utilizing activity of uncultured bacteria belonging to Synergistes group 4 and its competitive significance to acetoclastic methanogen, Methanosaeta. PMID:21562600

  11. Dried distillers grains with solubles do not always cause late blowing in baby Swiss cheese.

    PubMed

    Sankarlal, V Manimanna; Testroet, E D; Beitz, D C; Clark, S

    2015-12-01

    Late blowing in Swiss cheese, a result of unwanted gas production, is unacceptable to consumers and causes economic loss to manufacturers. Cheese processors have raised concerns that feeding dried distillers grains with solubles (DDGS) to cows leads to this defect, in part because of clostridial spores. We hypothesized that spores in DDGS would affect the quality of milk and baby Swiss cheese by promoting late-blowing defects. Thirty healthy multiparous and mid-lactation Holstein cows were fed total mixed ration containing DDGS (0, 10, and 20%; 10 cows per treatment group) by dietary dry matter in a 3×3 Latin square design. One complete milking from all cows within a treatment was collected and pooled for baby Swiss cheese, twice within each month of the 3-mo study. Additionally, individual milk samples from the 3 milkings of one day were collected weekly for proximate analysis. Incubation in reinforced clostridial medium-lactate medium tubes inoculated with milk, cheese, total mixed ration, or manure showed gas formation. Conversely, the DDGS used in our study did not contain gas-producing, spore-forming bacteria. Feeding 20% DDGS decreased milk fat percent and increased the solids nonfat, protein, and lactose percent of milk. After 60 d of ripening, baby Swiss cheese had typical propionic acid Swiss cheese aroma. Regardless of dietary treatment, pinholes, slits, splits, cracks, or a combination of these, were seen throughout most cheeses. Feeding of DDGS increased the amount of long-chain unsaturated fatty acids and decreased short-chain and most medium-chain fatty acids in the baby Swiss cheese. Although feeding cows diets with DDGS modified milk composition, and subsequently cheese composition, DDGS was not a source for gas-producing, spore-forming bacteria or for quality defects in Swiss cheese. Rather, the gas-producing, spore-forming bacteria likely originated from the environment or the cows themselves. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. The Role of Short-Chain Fatty Acids, Produced by Anaerobic Bacteria, in the Cystic Fibrosis Airway.

    PubMed

    Mirković, Bojana; Murray, Michelle A; Lavelle, Gillian M; Molloy, Kevin; Azim, Ahmed Abdul; Gunaratnam, Cedric; Healy, Fiona; Slattery, Dubhfeasa; McNally, Paul; Hatch, Joe; Wolfgang, Matthew; Tunney, Michael M; Muhlebach, Marianne S; Devery, Rosaleen; Greene, Catherine M; McElvaney, Noel G

    2015-12-01

    Anaerobic bacteria are present in large numbers in the airways of people with cystic fibrosis (PWCF). In the gut, anaerobes produce short-chain fatty acids (SCFAs) that modulate immune and inflammatory processes. To investigate the capacity of anaerobes to contribute to cystic fibrosis (CF) airway pathogenesis via SCFAs. Samples of 109 PWCF were processed using anaerobic microbiological culture with bacteria present identified by 16S RNA sequencing. SCFA levels in anaerobic supernatants and bronchoalveolar lavage (BAL) were determined by gas chromatography. The mRNA and/or protein expression of two SCFA receptors, GPR41 and GPR43, in CF and non-CF bronchial brushings and 16HBE14o(-) and CFBE41o(-) cells were evaluated using reverse transcription polymerase chain reaction, Western blot analysis, laser scanning cytometry, and confocal microscopy. SCFA-induced IL-8 secretion was monitored by ELISA. Fifty-seven (52.3%) of 109 PWCF were anaerobe positive. Prevalence increased with age, from 33.3% to 57.7% in PWCF younger (n = 24) and older (n = 85) than 6 years of age. All evaluated anaerobes produced millimolar concentrations of SCFAs, including acetic, propionic, and butyric acids. SCFA levels were higher in BAL samples of adults than in those of children. GPR41 levels were elevated in CFBE41o(-) versus 16HBE14o(-) cells; CF versus non-CF bronchial brushings; and 16HBE14o(-) cells after treatment with cystic fibrosis transmembrane conductance regulator inhibitor CFTR(inh)-172, CF BAL, or inducers of endoplasmic reticulum stress. SCFAs induced a dose-dependent and pertussis toxin-sensitive IL-8 response in bronchial epithelial cells, with a higher production of IL-8 in CFBE41o(-) than in 16HBE14o(-) cells. This study illustrates that SCFAs contribute to excessive production of IL-8 in CF airways colonized with anaerobes via up-regulated GPR41.

  13. The Role of Short-Chain Fatty Acids, Produced by Anaerobic Bacteria, in the Cystic Fibrosis Airway

    PubMed Central

    Murray, Michelle A.; Lavelle, Gillian M.; Molloy, Kevin; Azim, Ahmed Abdul; Gunaratnam, Cedric; Healy, Fiona; Slattery, Dubhfeasa; McNally, Paul; Hatch, Joe; Wolfgang, Matthew; Tunney, Michael M.; Muhlebach, Marianne S.; Devery, Rosaleen; Greene, Catherine M.; McElvaney, Noel G.

    2015-01-01

    Rationale: Anaerobic bacteria are present in large numbers in the airways of people with cystic fibrosis (PWCF). In the gut, anaerobes produce short-chain fatty acids (SCFAs) that modulate immune and inflammatory processes. Objectives: To investigate the capacity of anaerobes to contribute to cystic fibrosis (CF) airway pathogenesis via SCFAs. Methods: Samples of 109 PWCF were processed using anaerobic microbiological culture with bacteria present identified by 16S RNA sequencing. SCFA levels in anaerobic supernatants and bronchoalveolar lavage (BAL) were determined by gas chromatography. The mRNA and/or protein expression of two SCFA receptors, GPR41 and GPR43, in CF and non-CF bronchial brushings and 16HBE14o− and CFBE41o− cells were evaluated using reverse transcription polymerase chain reaction, Western blot analysis, laser scanning cytometry, and confocal microscopy. SCFA-induced IL-8 secretion was monitored by ELISA. Measurements and Main Results: Fifty-seven (52.3%) of 109 PWCF were anaerobe positive. Prevalence increased with age, from 33.3% to 57.7% in PWCF younger (n = 24) and older (n = 85) than 6 years of age. All evaluated anaerobes produced millimolar concentrations of SCFAs, including acetic, propionic, and butyric acids. SCFA levels were higher in BAL samples of adults than in those of children. GPR41 levels were elevated in CFBE41o− versus 16HBE14o− cells; CF versus non-CF bronchial brushings; and 16HBE14o− cells after treatment with cystic fibrosis transmembrane conductance regulator inhibitor CFTR(inh)-172, CF BAL, or inducers of endoplasmic reticulum stress. SCFAs induced a dose-dependent and pertussis toxin–sensitive IL-8 response in bronchial epithelial cells, with a higher production of IL-8 in CFBE41o− than in 16HBE14o− cells. Conclusions: This study illustrates that SCFAs contribute to excessive production of IL-8 in CF airways colonized with anaerobes via up-regulated GPR41. PMID:26266556

  14. Prevention of volatile fatty acids production and limitation of odours from winery wastewaters by denitrification.

    PubMed

    Bories, André; Guillot, Jean-Michel; Sire, Yannick; Couderc, Marie; Lemaire, Sophie-Andréa; Kreim, Virginie; Roux, Jean-Claude

    2007-07-01

    The effect of the addition of nitrate to winery wastewaters to control the formation of VFA in order to prevent odours during storage and treatment was studied in batch bioreactors at different NO(3)/chemical oxygen demand (COD) ratios and at full scale in natural evaporation ponds (2 x 7000 m(2)) by measuring olfactory intensity. In the absence of nitrate, butyric acid (2304 mgL(-1)), acetic acid (1633 mgL(-1)), propionic acid (1558 mgL(-1)), caproic acid (499 mgL(-1)) and valeric acid (298 mgL(-1)) were produced from reconstituted winery wastewater. For a ratio of NO(3)/COD=0.4 gg(-1), caproic and valeric acids were not formed. The production of butyric and propionic acids was reduced by 93.3% and 72.5%, respectively, at a ratio of NO(3)/COD=0.8, and by 97.4% and 100% at a ratio of NO(3)/COD=1.2 gg(-1). Nitrate delayed and decreased butyric acid formation in relation to the oxidoreduction potential. Studies in ponds showed that the addition of concentrated calcium nitrate (NITCAL) to winery wastewaters (3526 m(3)) in a ratio of NO(3)/COD=0.8 inhibited VFA production, with COD elimination (94%) and total nitrate degradation, and no final nitrite accumulation. On the contrary, in ponds not treated with nitrate, malodorous VFA (from propionic to heptanoïc acids) represented up to 60% of the COD. Olfactory intensity measurements in relation to the butanol scale of VFA solutions and the ponds revealed the pervasive role of VFA in the odour of the untreated pond as well as the clear decrease in the intensity and not unpleasant odour of the winery wastewater pond enriched in nitrates. The results obtained at full scale underscored the feasibility and safety of the calcium nitrate treatment as opposed to concentrated nitric acid.

  15. Fast determination of phenoxy acid herbicides in carrots and apples using liquid chromatography coupled triple quadrupole mass spectrometry.

    PubMed

    Santilio, Angela; Stefanelli, Patrizia; Dommarco, Roberto

    2009-08-01

    A fast, simple and inexpensive method has been developed for the analysis of phenoxy acid herbicides: 2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxyacetic acid (MCPA), 2-(4-chloro-o-tolyloxy)propionic acid (MCPP), 2-(4-aryloxyphenoxy)propionic acid (Fluazifop) and 2-(4-aryloxyphenoxy)propionic acid (Haloxyfop) in carrots and apples by liquid chromatography coupled to triple quadrupole mass spectrometry (LC/MS/MS). The compounds were analyzed by QuEChERS (quick, easy, cheap, effective, rugged, safe) methodology without cleanup. The recoveries were performed at two spiked levels (0.05 and 0.5 mg/kg) for both matrices with six replicates for each level. The mean recoveries ranged from 70-92% for both apples and carrots. The precision of the method expressed as relative standard deviation (RSD%) was found to be in the range 3-15%. For all compounds, good linearity (r(2) > 0.99) was obtained over the range of concentration from 0.05 micro g/mL to 0.5 micro g/mL, corresponding to the pesticide concentrations of 0.05 mg/kg and 0.5 mg/kg, respectively. The determination limits (LOQs) ranged from 0.01 ng/mL to 1.3 ng/mL in solvent, whereas, the LOQs calculated in matrix ranged from 0.05 ng/g to 21.0 ng/g for apples and from 0.06 ng/g to 10.2 ng/g for carrots. The developed methodology combines the advantages of both QuEChERS and LC/MS/MS producing a very rapid, sensitive and cheap method useful for the routine analytical laboratories.

  16. High-Fat Diet Reduces the Formation of Butyrate, but Increases Succinate, Inflammation, Liver Fat and Cholesterol in Rats, while Dietary Fibre Counteracts These Effects

    PubMed Central

    Jakobsdottir, Greta; Xu, Jie; Molin, Göran; Ahrné, Siv; Nyman, Margareta

    2013-01-01

    Introduction Obesity is linked to type 2 diabetes and risk factors associated to the metabolic syndrome. Consumption of dietary fibres has been shown to have positive metabolic health effects, such as by increasing satiety, lowering blood glucose and cholesterol levels. These effects may be associated with short-chain fatty acids (SCFAs), particularly propionic and butyric acids, formed by microbial degradation of dietary fibres in colon, and by their capacity to reduce low-grade inflammation. Objective To investigate whether dietary fibres, giving rise to different SCFAs, would affect metabolic risk markers in low-fat and high-fat diets using a model with conventional rats for 2, 4 and 6 weeks. Material and Methods Conventional rats were administered low-fat or high-fat diets, for 2, 4 or 6 weeks, supplemented with fermentable dietary fibres, giving rise to different SCFA patterns (pectin – acetic acid; guar gum – propionic acid; or a mixture – butyric acid). At the end of each experimental period, liver fat, cholesterol and triglycerides, serum and caecal SCFAs, plasma cholesterol, and inflammatory cytokines were analysed. The caecal microbiota was analysed after 6 weeks. Results and Discussion Fermentable dietary fibre decreased weight gain, liver fat, cholesterol and triglyceride content, and changed the formation of SCFAs. The high-fat diet primarily reduced formation of SCFAs but, after a longer experimental period, the formation of propionic and acetic acids recovered. The concentration of succinic acid in the rats increased in high-fat diets with time, indicating harmful effect of high-fat consumption. The dietary fibre partly counteracted these harmful effects and reduced inflammation. Furthermore, the number of Bacteroides was higher with guar gum, while noticeably that of Akkermansia was highest with the fibre-free diet. PMID:24236183

  17. Comparative evaluation of laboratory-scale silages using standard glass jar silages or vacuum-packed model silages.

    PubMed

    Hoedtke, Sandra; Zeyner, Annette

    2011-03-30

    The objective of this study was to compare the fermentation variables of laboratory-scale silages made in glass preserving jars (GLASS) and vacuum-packed plastic bags (Rostock model silages, ROMOS). Silages were prepared from perennial ryegrass (fresh and wilted, 151 g kg(-1) and 286 g kg(-1) dry matter (DM), respectively) and remoistened coarsely ground rye grain (650 g kg(-1) DM) either with or without the addition of a lactic acid bacteria inoculant (3×10(5) colony forming units (cfu) g(-1) , LAB). Quintuplicate silos were opened on days 2, 4, 8, 49 and 90. Silage pH (P=0.073), acetic acid content (P=0.608) and ethanol content (P=0.223) were not influenced by the ensiling method. The contents of DM (P<0.001) and propionic acid (P=0.008) were affected by the ensiling method, but mean differences were only marginal. In ROMOS the concentration of lactic acid was increased (P=0.007) whereas butyric acid was produced less (P=0.001) when compared to GLASS. This suggested slightly better ensiling conditions for ROMOS. ROMOS represents a reasonable alternative to glass jar silages and opens the possibility for further investigations, e.g. studying the impact of packing density as well as the quantitative and qualitative analysis of fermentation gases. Copyright © 2010 Society of Chemical Industry.

  18. Complete Oxidation of Propionate, Valerate, Succinate, and Other Organic Compounds by Newly Isolated Types of Marine, Anaerobic, Mesophilic, Gram-Negative, Sulfur-Reducing Eubacteria

    PubMed Central

    Finster, Kai; Bak, Friedhelm

    1993-01-01

    Anaerobic enrichment cultures with either propionate, succinate, lactate, or valerate and elemental sulfur and inocula from shallow marine or deep-sea sediments were dominated by rod-shaped motile bacteria after three transfers. By application of deep-agar dilutions, five eubacterial strains were obtained in pure culture and designated Kyprop, Gyprop, Kysw2, Gylac, and Kyval. All strains were gram negative and grew by complete oxidation of the electron donors and concomitant stoichiometric reduction of elemental sulfur to hydrogen sulfide. The isolates used acetate, propionate, succinate, lactate, pyruvate, oxaloacetate, maleate, glutamate, alanine, aspartate, and yeast extract. All isolates, except strain Gylac, used citrate as an electron donor but valerate was oxidized only by strain Kyval. Fumarate and malate were degraded by all strains without an additional electron donor or acceptor. Kyprop, Gyprop, and Gylac utilized elemental sulfur as the sole inorganic electron acceptor, while Kysw2 and Kyval also utilized nitrate, dimethyl sulfoxide, or Fe(III)-citrate as an electron acceptor. Images PMID:16348934

  19. Increased colonic propionate reduces anticipatory reward responses in the human striatum to high-energy foods.

    PubMed

    Byrne, Claire S; Chambers, Edward S; Alhabeeb, Habeeb; Chhina, Navpreet; Morrison, Douglas J; Preston, Tom; Tedford, Catriona; Fitzpatrick, Julie; Irani, Cherag; Busza, Albert; Garcia-Perez, Isabel; Fountana, Sofia; Holmes, Elaine; Goldstone, Anthony P; Frost, Gary S

    2016-07-01

    Short-chain fatty acids (SCFAs), metabolites produced through the microbial fermentation of nondigestible dietary components, have key roles in energy homeostasis. Animal research suggests that colon-derived SCFAs modulate feeding behavior via central mechanisms. In humans, increased colonic production of the SCFA propionate acutely reduces energy intake. However, evidence of an effect of colonic propionate on the human brain or reward-based eating behavior is currently unavailable. We investigated the effect of increased colonic propionate production on brain anticipatory reward responses during food picture evaluation. We hypothesized that elevated colonic propionate would reduce both reward responses and ad libitum energy intake via stimulation of anorexigenic gut hormone secretion. In a randomized crossover design, 20 healthy nonobese men completed a functional magnetic resonance imaging (fMRI) food picture evaluation task after consumption of control inulin or inulin-propionate ester, a unique dietary compound that selectively augments colonic propionate production. The blood oxygen level-dependent (BOLD) signal was measured in a priori brain regions involved in reward processing, including the caudate, nucleus accumbens, amygdala, anterior insula, and orbitofrontal cortex (n = 18 had analyzable fMRI data). Increasing colonic propionate production reduced BOLD signal during food picture evaluation in the caudate and nucleus accumbens. In the caudate, the reduction in BOLD signal was driven specifically by a lowering of the response to high-energy food. These central effects were partnered with a decrease in subjective appeal of high-energy food pictures and reduced energy intake during an ad libitum meal. These observations were not related to changes in blood peptide YY (PYY), glucagon-like peptide 1 (GLP-1), glucose, or insulin concentrations. Our results suggest that colonic propionate production may play an important role in attenuating reward-based eating behavior via striatal pathways, independent of changes in plasma PYY and GLP-1. This trial was registered at clinicaltrials.gov as NCT00750438.

  20. Crystal structure of 3-(2,5-di-meth-oxy-phen-yl)propionic acid.

    PubMed

    Bugenhagen, Bernhard; Al Jasem, Yosef; AlAzani, Mariam; Thiemann, Thies

    2015-05-01

    In the crystal of the title compound, C11H14O4, the aromatic ring is almost coplanar with the 2-position meth-oxy group with which it subtends a dihedral of 0.54 (2)°, while the 5-position meth-oxy group makes a corresponding dihedral angle of just 5.30 (2)°. The angle between the mean planes of the aromatic ring and the propionic acid group is 78.56 (2)°. The fully extended propionic side chain is in a trans configuration with a C-C-C-C torsion angle of -172.25 (7)°. In the crystal, hydrogen bonding is limited to dimer formation via R 2 (2)(8) rings. The hydrogen-bonded dimers are stacked along the b axis. The average planes of the two benzene rings in a dimer are parallel to each other, but at an offset of 4.31 (2) Å. Within neighbouring dimers along the [101] direction, the average mol-ecular benzene planes are almost perpendicular to each other, with a dihedral angle of 85.33 (2)°.

  1. Synthesis of Geraniol Esters in a Continuous-Flow Packed-Bed Reactor of Immobilized Lipase: Optimization of Process Parameters and Kinetic Modeling.

    PubMed

    Salvi, Harshada M; Kamble, Manoj P; Yadav, Ganapati D

    2018-02-01

    With increasing demand for perfumes, flavors, beverages, and pharmaceuticals, the various associated industries are resorting to different approaches to enhance yields of desired compounds. The use of fixed-bed biocatalytic reactors in some of the processes for making fine chemicals will be of great value because the reaction times could be reduced substantially as well as high conversion and yields obtained. In the current study, a continuous-flow packed-bed reactor of immobilized Candida antarctica lipase B (Novozym 435) was employed for synthesis of various geraniol esters. Optimization of process parameters such as biocatalyst screening, effect of solvent, mole ratio, temperature and acyl donors was studied in a continuous-flow packed-bed reactor. Maximum conversion of ~ 87% of geranyl propionate was achieved in 15 min residence time at 70 °C using geraniol and propionic acid with a 1:1 mol ratio. Novozym 435 was found to be the most active and stable biocatalyst among all tested. Ternary complex mechanism with propionic acid inhibition was found to fit the data.

  2. Effects of traditional Chinese medicine formula on ruminal fermentation, enzyme activities and nutrient digestibility of beef cattle.

    PubMed

    Zhu, Zhi; Song, Zhen-Hui; Cao, Li-Ting; Wang, Yong; Zhou, Wen-Zhang; Zhou, Pei; Zuo, Fu-Yuan

    2018-04-01

    This study was conducted to evaluate effects of traditional Chinese medicine formula (TCMF) combined with several herbs on ruminal fermentation, enzyme activities and nutrient digestibility. Twenty finishing bulls were assigned to control or different TCMFs (Yufeisan-1, -2, -3; 2.5% dry matter (DM) in concentrate). Results showed that DM intake was higher (P < 0.05) in the Yufeisan-3 group than others. Compared to control, apparent digestibility of crude protein and neutral detergent fiber were increased (P < 0.05) by Yufeisan-3. No changes were observed in ruminal pH, concentrations of ammonia-N, microbial crude protein and total volatile fatty acid, whereas ratio of acetate to propionate was lower (P < 0.05) and propionate proportion tended to be higher (P < 0.1) in three TCMFs than control. Ruminal xylanase (P = 0.061) and carboxymethylcellulase (P < 0.05) activities were higher in Yufeisan-3 than control. No changes were observed in abundance of total bacteria, fungi and protozoa, whereas Fibrobacter succinogenes (P = 0.062) and Ruminococcus flavefaciens (P < 0.05) were increased and total methanogens was reduced (P = 0.069) by Yufeisan-3 compared to control. Yufeisan-3 improved nutrient digestibility and ruminal enzyme activity, and modified fermentation and microbial community, maybe due to the presence of Herba agastaches, Cortex phellodendri and Gypsum fibrosum. © 2018 Japanese Society of Animal Science.

  3. Effects of 2-hydroxy-4-(methylthio) butanoic acid (HMB) on microbial growth in continuous culture.

    PubMed

    Noftsger, S M; St-Pierre, N R; Karnati, S K R; Firkins, J L

    2003-08-01

    2-Hydroxy-4-(methylthio) butanoic acid (HMB) positively affects milk composition and yield, potentially through ruminal actions. Four continuous culture fermenters were used to determine the optimal concentration of HMB for digestibility of organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicellulose and synthesis of microbial N. A highly degradable mix of hay and grain was used as a basal diet to simulate a typical lactation diet. Three concentrations of HMB (0, 0.055, and 0.110%) and one concentration of dl-Met (0.097%) were infused into the fermenters according to a 4 x 4 Latin square design. Digesta samples were collected during the last 3 d of each of the four 10-d experimental periods. Digestibility of OM, hemicellulose, and NDF was largely insensitive to treatment. Digestibility of ADF showed a quadratic effect to supplementation of HMB, with 0.055% having lower digestibility than 0 or 0.110%. Total production of VFA was not influenced by HMB supplementation, but differences in concentration and production of individual VFA were seen. Isobutyrate increased linearly with increasing HMB supplementation. Propionate concentration decreased linearly with increased HMB supplementation, but propionate production showed a quadratic trend (P = 0.13). A higher concentration of acetate was detected for dl-Met compared with the highest HMB concentration. There were trends (P < 0.15) for dl-Met to decrease the production of isobutyrate and to lower the concentration of butyrate when compared with HMB. Microbial efficiency was not different among treatments. The proportion of bacterial N produced from NH3-N decreased linearly with increasing HMB, and bacteria receiving dl-Met synthesized more N from NH3-N than those receiving HMB. These data suggest that supplementation of HMB may have a sparing effect on branched chain volatile fatty acids because the fatty acids are not needed to provide carbon for synthesis of valine, isoleucine and leucine with ammonia. Comparisons of bacterial community structure in the fermenter effluent samples using PCR amplicons containing the ribosomal intergenic spacer region and its flanking partial 16S ribosomal RNA gene showed no distinct banding patterns, though treatments tended to group together. Both Met and HMB affect the rumen microbial population, but Met supplied as dl-Met does not act identically to that supplied as HMB.

  4. Impact of anti-acidification microbial consortium on carbohydrate metabolism of key microbes during food waste composting.

    PubMed

    Song, Caihong; Li, Mingxiao; Qi, Hui; Zhang, Yali; Liu, Dongming; Xia, Xunfeng; Pan, Hongwei; Xi, Beidou

    2018-07-01

    This study investigated the effect of anti-acidification microbial consortium (AAMC), which act synergistically for rapid bioconversion of organic acids on carbohydrate metabolism of key microbes in the course of food waste (FW) composting by metaproteomics. AAMC was inoculated to the composting mass and compared with treatment with alkaline compounds and the control without any amendment. Inoculating AAMC could effectively accelerate carbohydrate degradation process and improve composting efficiency. Carbohydrate metabolic network profiles showed the inoculation with AAMC could increase significantly the types of enzymes catalysing the degradation of lignin, cellulose and hemicellulose. Furthermore, AAMC inoculum could increase not only diversities of microbes producing key enzymes in metabolism pathways of acetic and propionic acids, but also the amounts of these key enzymes. The increase of diversities of microbes could disperse the pressure from acidic adversity on microorganisms which were capable to degrade acetic and propionic acids. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. The one-stage autothermal thermophilic aerobic digestion for sewage sludge treatment: stabilization process and mechanism.

    PubMed

    Liu, Shugen; Zhu, Nanwen; Li, Loretta Y

    2012-01-01

    Batch experiment was carried out in a simulated thermophilic aerobic digester to investigate the digestion process of one-stage autothermal thermophilic aerobic digester and to explore the sludge stabilization mechanism. Volatile solids removal was 38.4% at 408 h and 45.0% at 552 h. Chemical oxidation demand, total nitrogen, and ammonia nitrogen in supernatant increased rapidly up to 168 h, and all of them fluctuated moderately after 360 h. Volatile fatty acid (VFA) accumulated rapidly up to 24 to 168 h, then declined sharply, reaching a low concentration after 312 h. Propionic, iso-valeric, and iso-butyric acids, in addition to acetic acids, were also the major components of VFA. As the biochemical metabolic process was inhibited under oxygen-deficiency condition, the digestion system can produce acetic, propionic, butyric acids and other VFA constituents to meet the demand for NAD(+) and maximize ATP generation. The ORP affected the VFA production and depletion as well as sulfate levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Propionic Acid Produced by Propionibacterium acnes Strains Contri-butes to Their Pathogenicity.

    PubMed

    Tax, Gábor; Urbán, Edit; Palotás, Zsuzsanna; Puskás, Róbert; Kónya, Zoltán; Bíró, Tamás; Kemény, Lajos; Szabó, Kornélia

    2016-01-01

    Propionibacterium acnes is an important member of the skin microbiome. The bacterium can initiate signalling events and changes in cellular properties in keratinocytes. The aim of this study was to analyse the effect of the bacterium on an immortalized human keratinocyte cell line. The results show that various P. acnes strains affect the cell-growth properties of these cells differentially, inducing cytotoxicity in a strain-specific and dose-dependent manner. We propose that bacterially secreted propionic acid may contribute to the cytotoxic effect. This acid has a role in maintaining skin pH and exhibits antimicrobial properties, but may also have deleterious effects when the local concentration rises due to excessive bacterial growth and metabolism. These results, together with available data from the literature, may provide insight into the dual role of P. acnes in healthy skin and during pathogenic conditions, as well as the key molecules involved in these functions.

  7. Functional Resilience and Response to a Dietary Additive (Kefir) in Models of Foregut and Hindgut Microbial Fermentation In Vitro

    PubMed Central

    de la Fuente, Gabriel; Jones, Eleanor; Jones, Shann; Newbold, Charles J.

    2017-01-01

    Stability in gut ecosystems is an important area of study that impacts on the use of additives and is related with several pathologies. Kefir is a fermented milk drink made with a consortium of yeast and bacteria as a fermentation starter, of which the use as additive in companion and livestock animals has increased in the last few years. To investigate the effect of kefir milk on foregut and hindgut digestive systems, an in vitro approach was followed. Either rumen fluid or horse fecal contents were used as a microbial inoculate and the inclusion of kefir (fresh, autoclaved, or pasteurized) was tested. Gas production over 72 h of incubation was recorded and pH, volatile fatty acids (VFAs), lactate and ammonia concentration as well as lactic acid (LAB) and acetic acid bacteria, and yeast total numbers were also measured. Both direct and indirect (by subtracting their respective blanks) effects were analyzed and a multivariate analysis was performed to compare foregut and hindgut fermentation models. Addition of kefir boosted the fermentation by increasing molar concentration of VFAs and ammonia and shifting the Acetate to Propionate ratio in both models but heat processing techniques like pasteurization or autoclaving influenced the way the kefir is fermented and reacts with the present microbiota. In terms of comparison between both models, the foregut model seems to be less affected by the inclusion of Kefir than the hindgut model. In terms of variability in the response, the hindgut model appeared to be more variable than the foregut model in the way that it reacted indirectly to the addition of different types of kefir. PMID:28702019

  8. Functional Resilience and Response to a Dietary Additive (Kefir) in Models of Foregut and Hindgut Microbial Fermentation In Vitro.

    PubMed

    de la Fuente, Gabriel; Jones, Eleanor; Jones, Shann; Newbold, Charles J

    2017-01-01

    Stability in gut ecosystems is an important area of study that impacts on the use of additives and is related with several pathologies. Kefir is a fermented milk drink made with a consortium of yeast and bacteria as a fermentation starter, of which the use as additive in companion and livestock animals has increased in the last few years. To investigate the effect of kefir milk on foregut and hindgut digestive systems, an in vitro approach was followed. Either rumen fluid or horse fecal contents were used as a microbial inoculate and the inclusion of kefir (fresh, autoclaved, or pasteurized) was tested. Gas production over 72 h of incubation was recorded and pH, volatile fatty acids (VFAs), lactate and ammonia concentration as well as lactic acid (LAB) and acetic acid bacteria, and yeast total numbers were also measured. Both direct and indirect (by subtracting their respective blanks) effects were analyzed and a multivariate analysis was performed to compare foregut and hindgut fermentation models. Addition of kefir boosted the fermentation by increasing molar concentration of VFAs and ammonia and shifting the Acetate to Propionate ratio in both models but heat processing techniques like pasteurization or autoclaving influenced the way the kefir is fermented and reacts with the present microbiota. In terms of comparison between both models, the foregut model seems to be less affected by the inclusion of Kefir than the hindgut model. In terms of variability in the response, the hindgut model appeared to be more variable than the foregut model in the way that it reacted indirectly to the addition of different types of kefir.

  9. Response of the Rumen Microbiota of Sika Deer (Cervus nippon) Fed Different Concentrations of Tannin Rich Plants

    PubMed Central

    Li, Zhipeng; Wright, André-Denis G.; Liu, Hanlu; Fan, Zhongyuan; Yang, Fuhe; Zhang, Zhigang; Li, Guangyu

    2015-01-01

    High throughput sequencing was used to examine the rumen microbiota of sika deer fed high (OLH) and low concentration (OLL) of tannin rich oak leaves. The results showed that Prevotella spp. were the most dominant bacteria. The most predominant methanogens were the members of the order Methanoplasmatales. The dominant rumen protozoa were Entodinium longinucleatum, Eudiplodinium maggii, and Epidinium caudatum, and the fungal communities were mostly represented by Piromyces spp. Moreover, the relative abundance of Pseudobutyrivibrio spp. (P=0.026), unidentified bacteria (P=0.028), and Prevotella spp. (P=0.022) was lower in the OLH group than in the OLL group. The concentration of propionate in the OLH group was greater than in the OLL group (P=0.006). Patterns of relationships showed that methanogens belonging to the order Methanoplasmatales were negatively correlated with Treponema spp., Ent. Longinucleatum, and acetate. Methanosphaera stadtmanae was positively correlated to propionate, while Methanobrevibacter ruminantium was negatively associated with Methanobrevibacter thaueri and Methanobrevibacter millerae. Tannins altered the rumen microbes and fermentation patterns. However, the response of the entire rumen microbiota and the relationship between rumen microorganisms and the fermentation parameters were not fully understood. PMID:25955033

  10. Isolation and survey of novel fluoroacetate-degrading bacteria belonging to the phylum Synergistetes.

    PubMed

    Davis, Carl K; Webb, Richard I; Sly, Lindsay I; Denman, Stuart E; McSweeney, Chris S

    2012-06-01

    Microbial dehalogenation of chlorinated compounds in anaerobic environments is well known, but the degradation of fluorinated compounds under similar conditions has rarely been described. Here, we report on the isolation of a bovine rumen bacterium that metabolizes fluoroacetate under anaerobic conditions, the mode of degradation and its presence in gut ecosystems. The bacterium was identified using 16S rRNA gene sequence analysis as belonging to the phylum Synergistetes and was designated strain MFA1. Growth was stimulated by amino acids with greater quantities of amino acids metabolized in the presence of fluoroacetate, but sugars were not fermented. Acetate, formate, propionate, isobutryate, isovalerate, ornithine and H(2) were end products of amino acid metabolism. Acetate was the primary end product of fluoroacetate dehalogenation, and the amount produced correlated with the stoichiometric release of fluoride which was confirmed using fluorine nuclear magnetic resonance ((19) F NMR) spectroscopy. Hydrogen and formate produced in situ were consumed during dehalogenation. The growth characteristics of strain MFA1 indicated that the bacterium may gain energy via reductive dehalogenation. This is the first study to identify a bacterium that can anaerobically dehalogenate fluoroacetate. Nested 16S rRNA gene-specific PCR assays detected the bacterium at low numbers in the gut of several herbivore species. © 2012 Commonwealth of Australia.

  11. Suitability of hardwood treated with phenoxy and pyridine herbicides for firewood use

    Treesearch

    P.B. Bush; D.G. Neary; Charles K. McMahon; J.W. Taylor

    1987-01-01

    Abstract. Potential exposure to pesticide residues resulting from burning wood treated with phenoxyand pyridine herbicides was assessed. Wood samples from trees treated with 2,4-D [2,4-dichlo-rophenoxy acetic acid], dicamba [3,6-dichloro-o-anisic acid], dichlorprop [2-(2,4-dichlorphenoxy) propionic acid], picloram [4-amino-3,5,dtrichloropico-linic...

  12. Camelina Seed Supplementation at Two Dietary Fat Levels Change Ruminal Bacterial Community Composition in a Dual-Flow Continuous Culture System

    PubMed Central

    Dai, Xiaoxia; Weimer, Paul J.; Dill-McFarland, Kimberly A.; Brandao, Virginia L. N.; Suen, Garret; Faciola, Antonio P.

    2017-01-01

    This experiment aimed to determine the effects of camelina seed (CS) supplementation at different dietary fat levels on ruminal bacterial community composition and how it relates to changes in ruminal fermentation in a dual-flow continuous culture system. Diets were randomly assigned to 8 fermenters (1,200–1,250 mL) in a 2 × 2 factorial arrangement of treatments in a replicated 4 × 4 Latin square with four 10-day experimental periods that consisted of 7 days for diet adaptation and 3 days for sample collection. Treatments were: (1) no CS at 5% ether extract (EE, NCS5); (2) no CS at 8% EE (NCS8); (3) 7.7% CS at 5% EE (CS5); and (4) 17.7% CS at 8% EE (CS8). Megalac was used as a control to adjust EE levels. Diets contained 55% orchardgrass hay and 45% concentrate, and fermenters were equally fed a total of 72 g/day (DM basis) twice daily. The bacterial community was determined by sequencing the V4 region of the 16S rRNA gene using the Illumina MiSeq platform. Sequencing data were analyzed using mothur and statistical analyses were performed in R and SAS. The most abundant phyla across treatments were the Bacteroidetes and Firmicutes, accounting for 49 and 39% of the total sequences, respectively. The bacterial community composition in both liquid and solid fractions of the effluent digesta changed with CS supplementation but not by dietary EE. Including CS in the diets decreased the relative abundances of Ruminococcus spp., Fibrobacter spp., and Butyrivibrio spp. The most abundant genus across treatments, Prevotella, was reduced by high dietary EE levels, while Megasphaera and Succinivibrio were increased by CS supplementation in the liquid fraction. Correlatively, the concentration of acetate was decreased while propionate increased; C18:0 was decreased and polyunsaturated fatty acids, especially C18:2 n-6 and C18:3 n-3, were increased by CS supplementation. Based on the correlation analysis between genera and fermentation end products, this study revealed that CS supplementation could be energetically beneficial to dairy cows by increasing propionate-producing bacteria and suppressing ruminal bacteria associated with biohydrogenation. However, attention should be given to avoid the effects of CS supplementation on suppressing cellulolytic bacteria. PMID:29163431

  13. Effects of concentrate-to-forage ratios and 2-methylbutyrate supplementation on ruminal fermentation, bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers.

    PubMed

    Wang, C; Liu, Q; Guo, G; Huo, W J; Pei, C X; Zhang, S L; Wang, H

    2018-05-01

    This study evaluated the effects of dietary concentrate levels and 2-methylbutyrate (2MB) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate-concentrate (400 g/kg diet [MC]) or high-concentrate (600 g/kg diet [HC]) diets were fed with or without 2MB (0 g/day [2MB-] or 15.0 g/day [2MB+]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate-to-propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH 3 -N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus, Ruminococcus flavefaciens, Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α-amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet. © 2018 Blackwell Verlag GmbH.

  14. Effect of solids retention time and temperature on waste activated sludge hydrolysis and short-chain fatty acids accumulation under alkaline conditions in continuous-flow reactors.

    PubMed

    Feng, Leiyu; Wang, Hua; Chen, Yinguang; Wang, Qin

    2009-01-01

    The effects of solids retention time (SRT) and temperature on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation were investigated in a series of continuous-flow reactors at pH 10. The experimental results showed that the increase of either SRT or temperature benefited the hydrolysis of WAS and the production of SCFAs. The changes in SRT gave also impact on the percentage of acetic and propionic acids in the fermentative SCFAs, but little influence on that of the slightly long-chain SCFAs, such as n-butyric, iso-butyric, n-valeric and iso-valeric acids. Compared with the control (pH unadjusted) experiment, at SRT of 12d and temperature of 20 degrees C the concentration of SCFAs produced at pH 10 increased from 261.2 to 933.5mg COD/L, and the propionic acid percentage improved from 11.7 to 16.0%. It can be concluded from this investigation that the efficient continuous production of SCFAs at pH 10 is feasible.

  15. Literature Survey on Causes of Spoilage of Fresh Produce - 1959 to 1977

    DTIC Science & Technology

    1982-08-01

    abscisic acid synthesis, and the enzymatic transformation of colorless carotenes to yellow, then orange, and finally red. 44. WJ. Lipton, 1967. Market...alamine, glycine, aspartic acid , glutamic acid , methionine, seraine, betaine methyl, glyoxalate, acrylate, propionate, ethanol, acetate, citrate...polygalacturonase forming monogalacturonic acid could not be detected. 23. MJ. Ceponis and J. Kaufman, 1968. Effect of Relative Humidity on Moisture Loss and Decay

  16. Butyrate: A dietary inhibitor of histone deacetylases and an epigenetic regulator

    USDA-ARS?s Scientific Manuscript database

    The short-chain fatty acids (SCFAs) acetate, propionate and butyrate, also known as volatile fatty acids (VFA), are produced in the gastrointestinal tract by microbial fermentation. Consumption of dietary fibers has been shown to have positive metabolic health effects, such as increasing satiety, an...

  17. Shifting the balance of fermentation products between hydrogen and volatile fatty acids: microbial community structure and function.

    PubMed

    Miceli, Joseph F; Torres, César I; Krajmalnik-Brown, Rosa

    2016-12-01

    Fermentation is a key process in many anaerobic environments. Varying the concentration of electron donor fed to a fermenting community is known to shift the distribution of products between hydrogen, fatty acids and alcohols. Work to date has focused mainly on the fermentation of glucose, and how the microbial community structure is affected has not been explored. We fed ethanol, lactate, glucose, sucrose or molasses at 100 me- eq. L -1 , 200 me- eq. L -1 or 400 me- eq. L -1 to batch-fed cultures with fermenting, methanogenic communities. In communities fed high concentrations of electron donor, the fraction of electrons channeled to methane decreased, from 34% to 6%, while the fraction of electrons channeled to short chain fatty acids increased, from 52% to 82%, averaged across all electron donors. Ethanol-fed cultures did not produce propionate, but did show an increase in electrons directed to acetate as initial ethanol concentration increased. In glucose, sucrose, molasses and lactate-fed cultures, propionate accumulation co-occurred with known propionate producing organisms. Overall, microbial communities were determined by the substrate provided, rather than its initial concentration, indicating that a change in community function, rather than community structure, is responsible for shifts in the fermentation products produced. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Long-Term Supplementation with Chromium Malate Improves Short Chain Fatty Acid Content in Sprague-Dawley Rats.

    PubMed

    Wu, Huiyu; Feng, Weiwei; Mao, Guanghua; Zhao, Ting; Wu, Xiangyang; Wang, Songmei; Zou, Yanmin; Yang, Liuqing; Wang, Liang

    2016-11-01

    Our previous study showed that chromium malate improved the composition of intestinal flora, glycometabolism, glycometabolism-related enzymes, and lipid metabolism in type 2 diabetes mellitus (T2DM) rats. The present study was designed to evaluate the effect of chromium malate with long-term supplementation on short chain fatty acid (SCFA) content in Sprague-Dawley rats. The samples were analyzed by gas chromatography with high linearity (R 2  ≥ 0.9995), low quantification limit (0.011-0.070 mM), and satisfactory recoveries. The method was simple and environmentally friendly. The acetic content in cecum of 3-month control group was significantly higher than that of 1-year control group. When compared with 1-year control group, chromium malate (at a dose of 20.0 μg Cr/kg bw) could significantly increase acetic, propionic, i-butyric butyric, butyric, i-valeric, valeric, and n-caproic levels. The acetic, propionic, i-butyric, valeric, and n-caproic contents of 1-year chromium malate group (at a dose of 20.0 μg Cr/kg bw) had a significant improvement when compared with 1-year chromium picolinate group. Acetic, propionic, and butyric contained approximately 91.65 % of the total SCFAs in 1-year group. The results indicated that the improvement of chromium malate on short chain fatty acid content change was better than that of chromium picolinate.

  19. 21 CFR 177.1200 - Cellophane.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Castor oil, sulfonated, sodium salt Cellulose acetate butyrate Cellulose acetate propionate Cetyl alcohol... trimethylenediamine (alkyl C16 to C18) Oleic acid, sulfonated, sodium salt Oleyl palmitamide N,N′-Oleoyl...

  20. Cloning and Expression of a Phloretin Hydrolase Gene from Eubacterium ramulus and Characterization of the Recombinant Enzyme

    PubMed Central

    Schoefer, Lilian; Braune, Annett; Blaut, Michael

    2004-01-01

    Phloretin hydrolase catalyzes the hydrolytic C-C cleavage of phloretin to phloroglucinol and 3-(4-hydroxyphenyl)propionic acid during flavonoid degradation in Eubacterium ramulus. The gene encoding the enzyme was cloned by screening a gene library for hydrolase activity. The insert of a clone conferring phloretin hydrolase activity was sequenced. Sequence analysis revealed an open reading frame of 822 bp (phy), a putative promoter region, and a terminating stem-loop structure. The deduced amino acid sequence of phy showed similarities to a putative protein of the 2,4-diacetylphloroglucinol biosynthetic operon from Pseudomonas fluorescens. The phloretin hydrolase was heterologously expressed in Escherichia coli and purified. The molecular mass of the native enzyme was approximately 55 kDa as determined by gel filtration. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the deduced amino acid sequence of phy indicated molecular masses of 30 and 30.8 kDa, respectively, suggesting that the enzyme is a homodimer. The recombinant phloretin hydrolase catalyzed the hydrolysis of phloretin to equimolar amounts of phloroglucinol and 3-(4-hydroxyphenyl)propionic acid. The optimal temperature and pH of the catalyzed reaction mixture were 37°C and 7.0, respectively. The Km for phloretin was 13 ± 3 μM and the kcat was 10 ± 2 s−1. The enzyme did not transform phloretin-2′-glucoside (phloridzin), neohesperidin dihydrochalcone, 1,3-diphenyl-1,3-propandione, or trans-1,3-diphenyl-2,3-epoxy-propan-1-one. The catalytic activity of the phloretin hydrolase was reduced by N-bromosuccinimide, o-phenanthroline, N-ethylmaleimide, and CuCl2 to 3, 20, 35, and 85%, respectively. Phloroglucinol and 3-(4-hydroxyphenyl)propionic acid reduced the activity to 54 and 70%, respectively. PMID:15466559

  1. Long-term stability of thermophilic co-digestion submerged anaerobic membrane reactor encountering high organic loading rate, persistent propionate and detectable hydrogen in biogas.

    PubMed

    Qiao, Wei; Takayanagi, Kazuyuki; Niu, Qigui; Shofie, Mohammad; Li, Yu You

    2013-12-01

    The performance of thermophilic anaerobic co-digestion of coffee grounds and sludge using membrane reactor was investigated for 148 days, out of a total research duration of 263 days. The OLR was increased from 2.2 to 33.7 kg-COD/m(3)d and HRT was shortened from 70 to 7 days. A significant irreversible drop in pH confirmed the overload of reactor. Under a moderately high OLR of 23.6 kg-COD/m(3)d, and with HRT and influent total solids of 10 days and 150 g/L, respectively, the COD removal efficiency was 44.5%. Hydrogen in biogas was around 100-200 ppm, which resulted in the persistent propionate of 1.0-3.2g/L. The VFA consumed approximately 60% of the total alkalinity. NH4HCO3 was supplemented to maintain alkalinity. The stability of system relied on pH management under steady state. The 16SrDNA results showed that hydrogen-utilizing methanogens dominates the archaeal community. The propionate-oxidizing bacteria in bacterial community was insufficient. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Does the intestinal microenvironment have an impact on the choleretic effect of inchinkoto, a hepatoprotective herbal medicine?

    PubMed

    Uji, Masahito; Yokoyama, Yukihiro; Asahara, Takashi; Ebata, Tomoki; Igami, Tsuyoshi; Mizuno, Takashi; Yamaguchi, Junpei; Nagino, Masato

    2018-02-01

    The choleretic effects of inchinkoto (ICKT), a hepatoprotective herbal medicine, are variable among patients. This study sought to investigate the correlation between the choleretic effects of ICKT and the intestinal microenvironment in patients with biliary obstruction. Patients with biliary obstruction who underwent external biliary drainage were enrolled. The concentrations of total bilirubin and bile acid in the bile, and genipin, a major active ingredient of ICKT, in the bloodstream before and after ICKT treatment were measured. Feces were collected from the patients to determine bacterial count and organic acid concentrations. Samples from 37 patients were collected and analyzed. The serum concentration of genipin increased 3 h after ICKT treatment and showed a positive correlation with the percent changes of biliary concentrations of bile acid, total bilirubin, and direct bilirubin. Serum genipin concentration also showed a positive correlation with the fecal concentrations of representative obligate anaerobes such as the Clostridium leptum subgroup, Bacteroides fragilis group, Bifidobacterium, and the Atopobium cluster. In sharp contrast, so-called harmful bacteria such as Clostridium difficile, Enterobacteriaceae, and Enterococcus showed a negative correlation with the concentration of genipin. Genipin concentration after ICKT administration showed a positive correlation with the fecal concentration of short chain fatty acids such as propionic acid and butyric acid, and a negative correlation with the fecal concentration of lactic acid. The absorption of genipin was variable among patients. This variability may be associated with the fecal microenvironment profile and partly explain the variable choleretic effects of ICKT among patients. © 2017 The Japan Society of Hepatology.

  3. Potassium sorbate reduces production of ethanol and 2 esters in corn silage.

    PubMed

    Hafner, Sasha D; Franco, Roberta B; Kung, Limin; Rotz, C Alan; Mitloehner, Frank

    2014-12-01

    The objective of this work was to evaluate the effects of biological and chemical silage additives on the production of volatile organic compounds (VOC; methanol, ethanol, 1-propanol, methyl acetate, and ethyl acetate) within corn silage. Recent work has shown that silage VOC can contribute to poor air quality and reduce feed intake. Silage additives may reduce VOC production in silage by inhibiting the activity of bacteria or yeasts that produce them. We produced corn silage in 18.9-L bucket silos using the following treatments: (1) control (distilled water); (2) Lactobacillus buchneri 40788, with 400,000 cfu/g of wet forage; (3) Lactobacillus plantarum MTD1, with 100,000 cfu/g; (4) a commercial buffered propionic acid-based preservative (68% propionic acid, containing ammonium and sodium propionate and acetic, benzoic, and sorbic acids) at a concentration of 1 g/kg of wet forage (0.1%); (5) a low dose of potassium sorbate at a concentration of 91 mg/kg of wet forage (0.0091%); (6) a high dose of potassium sorbate at a concentration of 1g/kg of wet forage (0.1%); and (7) a mixture of L. plantarum MTD1 (100,000 cfu/g) and a low dose of potassium sorbate (91 mg/kg). Volatile organic compound concentrations within silage were measured after ensiling and sample storage using a headspace gas chromatography method. The high dose of potassium sorbate was the only treatment that inhibited the production of multiple VOC. Compared with the control response, it reduced ethanol by 58%, ethyl acetate by 46%, and methyl acetate by 24%, but did not clearly affect production of methanol or 1-propanol. The effect of this additive on ethanol production was consistent with results from a small number of earlier studies. A low dose of this additive does not appear to be effective. Although it did reduce methanol production by 24%, it increased ethanol production by more than 2-fold and did not reduce the ethyl acetate concentration. All other treatments increased ethanol production at least 2-fold relative to the control, and L. buchneri addition also increased the 1-propanol concentration to approximately 1% of dry matter. No effects of any treatments on fiber fractions or protein were observed. However, L. buchneri addition resulted in slightly more ammonia compared with the control. If these results hold under different conditions, a high dose of potassium sorbate will be an effective treatment for reducing VOC production in and emission from silage. Regulations aimed at reducing VOC emission could be ineffective or even increase emission if they promote silage additives without recognition of different types of additives. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. [Dependence of rumen fatty acid production on the composition of rations].

    PubMed

    Lebzien, P; Rohr, K; Oslage, H J

    1981-10-01

    In three experiments with two Black-and-White dairy cows the influence of soybean oil and coconut fat as well as that of rations rich in roughage and concentrated feed on the production of fatty acids were determined with the isotope dilution method. A change in the method of sampling from the rumen in the course of the investigations resulted in distinctly different absolute production quotas, which can presumably be traced back to the disproportionate mixing in of the isotope and/or different production quotas in various regions of the rumen. The relative differences between the production quotas dependent on the rations, however were approximately the same with both sampling methods, so that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation between the relation of acetic and propionic acid in the rumen fluid and the quotient from acetic and propionic acid produced. In contrast to this, a significant relation between the concentration of fatty acids and the production of fatty acids could not be ascertained. Soybean oil and coconut fat brought about a slightly better utilisation of the fat-free organic matter for the production of fatty acids in the rumen. This could mainly be traced back to the increased production of propionic acid. The production of acetic acid per kg fat-free organic matter was insignificantly reduced. A reduced quota of roughage in the ration as well as the use of feed fats resulted in a decrease in the production of acetic acid and an increase in the production of propionic acid. The influence of the quota of roughage, however, was bigger than that of the use of fats. When rations rich in roughage were given, the share the energy contained in the total fatty acids has in the total of the digested energy was, on an average of both animals, slightly lower in comparison to rations rich in concentrated feed. However, the reason for this is not to be found in a lower share the energy digested in the stomachs has in the total of digested energy but in a higher amount of fermentation losses with a nutrition rich in roughage.

  5. In vitro fermentation of mulberry fruit polysaccharides by human fecal inocula and impact on microbiota.

    PubMed

    Chen, Chun; Huang, Qiang; Fu, Xiong; Liu, Rui Hai

    2016-11-09

    This study investigated the in vitro fermentation of polysaccharides from Morus alba L., the contribution of its carbohydrates to the fermentation, and the effect on the composition of gut microbiota. Over 48 h of fermentation, the pH value in the fecal culture decreased from 7.12 to 6.14, and the total short chain fatty acids (SCFA) and acetic, propionic, and butyric acids all significantly increased. After 48 h of fermentation, 45.36 ± 1.36% of the total carbohydrates in the polysaccharide, including 35.72 ± 1.51% of arabinose, 23.1 ± 1.19% of galactose, 41.43 ± 1.52% of glucose, 26.36 ± 1.93% of rhamnose and 65.57 ± 1.07% of galacturic acid, were consumed. The increase in acetic and butyric acids was primarily due to the fermentation of galactose and galacturonic acid in the polysaccharide, while the increase in propionic acid resulted mainly from the fermentation of arabinose and glucose. In addition, the polysaccharide could modulate the gut microbiota composition by increasing the Bacteroidetes population and decreasing the Firmicutes population. The results may facilitate the development of food products known as prebiotics, aimed at improving gastrointestinal health.

  6. Effects of dietary fiber preparations made from maize starch on the growth and activity of selected bacteria from the Firmicutes, Bacteroidetes, and Actinobacteria phyla in fecal samples from obese children.

    PubMed

    Barczynska, Renata; Slizewska, Katarzyna; Litwin, Mieczyslaw; Szalecki, Mieczyslaw; Kapusniak, Janusz

    2016-01-01

    Currently, there is a search for substances that would be very well tolerated by an organism and which could contribute to the activation of the growth of Bacteroidetes and Actinobacteria strains, with simultaneous inhibition of the growth of Firmicutes. High expectations in this regard are raised with the use of fiber preparations from starch - resistant corn dextrins, branched dextrins, resistant maltodextrins and soluble corn fiber. In this paper, the influence of fiber preparations made from corn starch was evaluated on growth and activity of Bacteroidetes, Actinobacteria and Firmicutes strains isolated from obese children. It was demonstrated that in the stool of obese children Firmicutes strains predominate, while Bacteroidetes and Actinobacteria strains were in the minority. A supplementation of fecal culture with fiber preparations did not cause any significant changes in the number of strains of Bacteroidetes and Firmicutes. Addition of fiber preparations to the fecal samples of obese children increased the amount of short-chain fatty acids, especially acetic (p < 0.01), propionic, butyric (p = 0.05) and lactic acid (p < 0.01).

  7. Effect of probiotics on the meat flavour and gut microbiota of chicken.

    PubMed

    Wang, Yan; Sun, Jing; Zhong, Hang; Li, Nianzhen; Xu, Hengyong; Zhu, Qing; Liu, Yiping

    2017-07-25

    To date, no report has demonstrated the use of beneficial microbes for contributing to the flavour characteristics and gut microbiota diversity of chicken. Here, we selected six probiotics obtained from our laboratory and supplemented them in six different combinations to 420 newborn male Qingjiaoma chickens under the same controlled living environment (60 birds, no probiotic supplements). The results showed that chicken supplemented with Bacillus species showed beneficial effects in body weight. Acetate is the major fermentation production in the chicken caecum, and chicken supplemented with Pediococcus pentosaceus had the average higher short chain fatty acids (SCFAs) contents. In chicken caecal microflora, the abundance of Bacteroidetes bacteria was positively correlated with the content of propionate, butyrate, and isobutyrate, whereas an increase in acetate content was positively correlated to the abundance of Firmicutes. Compared to chickens without probiotic supplement, chickens supplemented with P. pentosaceus had more characteristic flavour compounds in the sampled breast meat, especially higher concentrations of (E)-2-heptenal, (E,E)-2,4-nonadienal, and certain C6-C9 unsaturated fatty acids. This resulted in a stronger chicken-fatty or fatty odour which directly improved the flavour. These findings suggest that probiotics can improve chicken meat flavour and increase gut microbiota diversity.

  8. Genome Sequence of the Verrucomicrobium Opitutus terrae PB90-1, an Abundant Inhabitant of Rice Paddy Soil Ecosystems▿

    PubMed Central

    van Passel, Mark W. J.; Kant, Ravi; Palva, Airi; Copeland, Alex; Lucas, Susan; Lapidus, Alla; Glavina del Rio, Tijana; Pitluck, Sam; Goltsman, Eugene; Clum, Alicia; Sun, Hui; Schmutz, Jeremy; Larimer, Frank W.; Land, Miriam L.; Hauser, Loren; Kyrpides, Nikolaos; Mikhailova, Natalia; Richardson, P. Paul; Janssen, Peter H.; de Vos, Willem M.; Smidt, Hauke

    2011-01-01

    Bacteria of the deeply branching phylum Verrucomicrobia are rarely cultured yet commonly detected in metagenomic libraries from aquatic, terrestrial, and intestinal environments. We have sequenced the genome of Opitutus terrae PB90-1, a fermentative anaerobe within this phylum, isolated from rice paddy soil and capable of propionate production from plant-derived polysaccharides. PMID:21398538

  9. Reductions in DNAPL Longevity through Biological Flux Enhancement

    DTIC Science & Technology

    2009-01-01

    3 Phosphorus 2 Calcium 111 Magnesium 11 Sulfur 47 Bioavailable iron 31 Total iron 198 Porosity 0.32 Conductivity 0.97 mmohs cm-1 Organic...acetate, propionate, and lactate were analyzed by filtering aqueous samples (2.7 mL) through a syringe filter (0.22 μm) containing 0.3 M oxalic acid...acid Nitric acid, glycol, peroxides, permanganates Acetone Conc. nitric and sulfuric acids Ammonia, anhydrous Halogens, calcium hypochlorite (bleach

  10. Understanding of how Propionibacterium acidipropionici respond to propionic acid stress at the level of proteomics

    PubMed Central

    Guan, Ningzi; Shin, Hyun-dong; Chen, Rachel R.; Li, Jianghua; Liu, Long; Du, Guocheng; Chen, Jian

    2014-01-01

    Propionic acid (PA) is an important platform chemical in the food, agriculture, and pharmaceutical industries and is mainly biosynthesized by propionibacteria. Acid tolerance in PA-producing strains is crucial. In previous work, we investigated the acid tolerance mechanism of Propionibacterium acidipropionici at microenvironmental levels by analyzing physiological changes in the parental strain and three PA-tolerant mutants obtained by genome shuffling. However, the molecular mechanism of PA tolerance in P. acidipropionici remained unclear. Here, we performed a comparative proteomics study of P. acidipropionici CGMCC 1.2230 and the acid-tolerant mutant P. acidipropionici WSH1105; MALDI-TOF/MS identified 24 proteins that significantly differed between the parental and shuffled strains. The differentially expressed proteins were mainly categorized as key components of crucial biological processes and the acid stress response. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was used to confirm differential expression of nine key proteins. Overexpression of the secretory protein glyceraldehyde-3-phosphate dehydrogenase and ATP synthase subunit α in Escherichia coli BL21 improved PA and acetic acid tolerance; overexpression of NADH dehydrogenase and methylmalonyl-CoA epimerase improved PA tolerance. These results provide new insights into the acid tolerance of P. acidipropionici and will facilitate the development of PA production through fermentation by propionibacteria. PMID:25377721

  11. Rumen Bacteria Communities and Performances of Fattening Lambs with a Lower or Greater Subacute Ruminal Acidosis Risk

    PubMed Central

    Li, Fei; Wang, Zhilan; Dong, Chunxiao; Li, Fadi; Wang, Weimin; Yuan, Zehu; Mo, Futao; Weng, Xiuxiu

    2017-01-01

    Several ruminal cellulolytic bacteria species are sensitive to pH and could therefore be used as biomarkers to determine the risk of sub-acute ruminal acidosis (SARA) in finishing lambs. This study compared a 2–4 h post feeding ruminal pH measurement to abundances of the ruminal pH-sensitive bacteria to evaluate the risk of SARA in a herd of 120 finishing lambs. The lambs were reared in individual units for 50 days. Ruminal fluid was collected by use of an orogastric tube on day 51 2-4 h after feeding. Although the lambs were fed an identical diet, they responded differently in the abundances of four ruminal pH sensitive cellulolytic bacteria (Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes and Butyrivibrio fibrisolvens). Lambs with the most or the least cellulolytic bacteria were then classified as either lower SARA risk (LSR, n = 10) or higher SARA risk group (HSR, n = 10), respectively. Data showed that the ruminal pH and VFA profiles were uncorrelated with the number of cellulolytic bacteria (P > 0.050). Lambs with the HSR showed lower ruminal pH (P = 0.013) and acetate to propionate ratio (P = 0.018), higher concentrations of lactate (P = 0.035) and proportion of propionate (P = 0.033) compared to those with the LSR. The DMI and ADG did not differ in LSR and HSR lambs (P > 0.050). A diversity analysis revealed significantly lower diversity in HSR lambs than in LSR (Simpson index, P = 0.004). The relative abundances of the phyla Bacteroidetes, Fibrobacteres, Verruomicrobia, and Proteobacteria were higher in LSR lambs than in HSR (P < 0.050). The abundances of several phyla including Firmicutes, Tenericutes and Actinobacteria were higher in the HSR than in the LSR group (P < 0.050). The bacterial communities of the LSR and HSR clustered separately in rumen based on the Unifrac distances, indicating distinct bacteria communities at OTU level between the LSR and HSR lambs. Overall, there was no correlation between 2 and 4 h post-feeding ruminal pH and the abundance of pH-sensitive bacteria and the amount of these bacteria could be used as a potential biomarker of SARA in lamb herd. PMID:29312208

  12. Use of a colon simulation technique to assess the effect of live yeast on fermentation parameters and microbiota of the colon of pig.

    PubMed

    Pinloche, E; Williams, M; D'Inca, R; Auclair, E; Newbold, C J

    2012-12-01

    The impact of 2 doses of a Saccharomyces cerevisiae were evaluated, 5 × 10(10) cfu/kg of feed (L1) and 5 × 10(11) cfu/kg of feed (L2) against a control (CON) with no added yeast, using an in vitro model [colon simulation technique (Cositec)] to mimic digestion in the pig colon. The L2 (but not L1) dose significantly improved DM digestibility compared to CON (61 v 58%) and increased NH(3) concentrations (+15%). Volatile fatty acid concentrations increased with L2 compared to CON--isobutyrate (+13.5%), propionate (+8.5%), isovalerate (+17.8%), and valerate (+25%)--but only valerate was increased with L1 (+14.2%). The analysis of microbiota from the liquid associated bacteria (LAB) and solid associated bacteria (SAB) revealed an interaction between the fraction and treatment (P < 0.05). Indeed, L2 had a significant impact on SAB and LAB (P < 0.01) whereas L1 only tended to change the structure of the population in the SAB (P < 0.1). Overall, this study showed that a live yeast probiotic could improve digestion in a colonic simulation model but only at the higher dose used and this effect was associated with a shift in the bacterial population therein.

  13. 21 CFR 184.1081 - Propionic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., 2101 Constitution Ave. NW., Washington, DC 20418, or available for inspection at the National Archives... 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr...

  14. Anaerobic biodegradation of methyl esters by Acetobacterium woodii and Eubacterium limosum

    USGS Publications Warehouse

    Liu, Shi; Suflita, Joseph M.

    1994-01-01

    The ability ofAcetobacterium woodii andEubacterium limosum to degrade methyl esters of acetate, propionate, butyrate, and isobutyrate was examined under growing and resting-cell conditions. Both bacteria hydrolyzed the esters to the corresponding carboxylates and methanol under either condition. Methanol was further oxidized to formate under growing but not resting conditions. Unlike the metabolism of phenylmethylethers, no H2 requirement was evident for ester biotransformation. The hydrolysis of methyl carboxylates is thermodynamically favorable under standard conditions and the mixotrophic metabolism of ester/CO2 allowed for bacterial growth. These results suggest that the degradation of methyl carboxylates may be a heretofore unrecognized nutritional option for acetogenic bacteria.

  15. Fermentation by the human large intestine microbial community in an in vitro semicontinuous culture system.

    PubMed Central

    Miller, T L; Wolin, M J

    1981-01-01

    A semicontinuous culture of the microbial community of the human large intestine that was maintained over 81 days is described. The initial inoculum was feces, and about 200 ml of nutrient suspension was fed to 500 ml of fermentor contents once or twice daily. The nutrient suspension contained comminuted fibrous food, sodium deoxycholate, urea, acid-hydrolyzed casein, vitamins, and salts. The fermentation was monitored, and the major products were acetate, propionate, butyrate, methane, hydrogen, and carbon dioxide. The concentration of anaerobic bacteria was 2 X 10(9) per ml of culture contents and was 100 times that of fecal coliforms. When the nutrient suspension contained lettuce, celery, carrots, and unsweetened applesauce, the predominant nonsporeforming anaerobes isolated were Bacteroides species. When carrots and applesauce were omitted, the predominant nonsporeforming isolates were Fusobacterium species. On both diets, clostridia were isolated that resembled Clostridium clostridiiforme. The fermentation and bacteriological analyses indicated that the in vitro ecosystem appears to be a reasonable facsimile of the large intestine ecosystem. Images PMID:7027952

  16. Reactivation of Escherichia coli cells, inactivated by ultraviolet rays, with cell extracts of propionic acid bacteria: Fractionation of the extract

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

    Vorob`eva, L.I.; Khodzhaev, E.Yu.; Ponomareva, G.M.

    1995-01-01

    Separation of Propionibacterium shermanii extract into fractions and testing them for their reactivating effect on UV-inactivated Escherichia coli AB-1157 cells showed that the activity was associated with the fraction of soluble proteins. The activity was not demonstrated in the fractions of RNA, DNA, ribosomes, or cell walls. Fractional salting out and subsequent testing of the fractions showed two active protein fractions: fraction I (20-40% of ammonium sulfate saturating concentration) and fraction II (60-80%). These fractions were separated by HPLC into seven and eight subfractions, respectively. Reactivating activity was showed in subfraction 4 (fraction I) and subfractions 5 and 6 (fractionmore » II). Electrophoresis showed five and four polypeptides in subfractions 4 and 5, respectively. Subfraction 6 (fraction II) contained one protein with a molecular mass of about 30 kDa. This protein, apparently, was responsible for the protective properties of fraction II. 9 refs., 2 figs., 4 tabs.« less

  17. 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.

  18. Comparative Analysis of the Microbiota Between Sheep Rumen and Rabbit Cecum Provides New Insight Into Their Differential Methane Production

    PubMed Central

    Mi, Lan; Yang, Bin; Hu, Xialu; Luo, Yang; Liu, Jianxin; Yu, Zhongtang; Wang, Jiakun

    2018-01-01

    The rumen and the hindgut represent two different fermentation organs in herbivorous mammals, with the former producing much more methane than the latter. The objective of this study was to elucidate the microbial underpinning of such differential methane outputs between these two digestive organs. Methane production was measured from 5 adult sheep and 15 adult rabbits, both of which were placed in open-circuit respiratory chambers and fed the same diet (alfalfa hay). The sheep produced more methane than the rabbits per unit of metabolic body weight, digestible neutral detergent fiber, and acid detergent fiber. pH in the sheep rumen was more than 1 unit higher than that in the rabbit cecum. The acetate to propionate ratio in the rabbit cecum was more than threefold greater than that in the sheep rumen. Comparative analysis of 16S rRNA gene amplicon libraries revealed distinct microbiota between the rumen of sheep and the cecum of rabbits. Hydrogen-producing fibrolytic bacteria, especially Butyrivibrio, Succiniclastium, Mogibacterium, Prevotella, and Christensenellaceae, were more predominant in the sheep rumen, whereas non-hydrogen producing fibrolytic bacteria, such as Bacteroides, were more predominant in the rabbit cecum. The rabbit cecum had a greater predominance of acetogens, such as those in the genus Blautia, order Clostridiales, and family Ruminococcaceae. The differences in the occurrence of hydrogen-metabolizing bacteria probably explain much of the differential methane outputs from the rumen and the cecum. Future research using metatranscriptomics and metabolomics shall help confirm this premise and understand the factors that shape the differential microbiota between the two digestive organs. Furthermore, our present study strongly suggests the presence of new fibrolytic bacteria in the rabbit cecum, which may explain the stronger fibrolytic activities therein. PMID:29662480

  19. Oleaginous yeast Yarrowia lipolytica culture with synthetic and food waste-derived volatile fatty acids for lipid production.

    PubMed

    Gao, Ruiling; Li, Zifu; Zhou, Xiaoqin; Cheng, Shikun; Zheng, Lei

    2017-01-01

    The sustainability of microbial lipids production from traditional carbon sources, such as glucose or glycerol, is problematic given the high price of raw materials. Considerable efforts have been directed to minimize the cost and find new alternative carbon sources. Volatile fatty acids (VFAs) are especially attractive raw materials, because they can be produced from a variety of organic wastes fermentation. Therefore, the use of volatile fatty acids as carbon sources seems to be a feasible strategy for cost-effective microbial lipid production. Lipid accumulation in Y. lipolytica using synthetic and food waste-derived VFAs as substrates was systematically compared and evaluated in batch cultures. The highest lipid content obtained with acetic, butyric, and propionic acids reached 31.62 ± 0.91, 28.36 ± 0.74, and 28.91 ± 0.66%, respectively. High concentrations of VFA inhibited cell growth in the following order: butyric acid > propionic acid > acetic acid. Within a 30-day experimental period, Y. lipolytica could adapt up to 20 g/L acetic acid, whereas the corresponding concentration of propionic acid and butyric acid were 10 and 5 g/L, respectively. Cultures on a VFA mixture showed that the utilization of different types of VFA by Y. lipolytica was not synchronized but rather performed in a step-wise manner. Although yeast fermentation is an exothermic process, and the addition of VFA will directly affect the pH of the system by increasing environmental acidity, cultures at a cultivation temperature of 38 °C and uncontrolled pH demonstrated that Y. lipolytica had high tolerance in the high temperature and acidic environment when a low concentration (2.5 g/L) of either synthetic or food waste-derived VFA was used. However, batch cultures fed with food fermentate yielded lower lipid content (18.23 ± 1.12%) and lipid productivity (0.12 ± 0.02 g/L/day). The lipid composition obtained with synthetic and food waste-derived VFA was similar to commercial biodiesel feedstock. This work demonstrated the feasibility of utilizing synthetic and food waste-derived VFA for lipid production by Y. lipolytica . The good adaptability of Y. lipolytica to the high temperature and acidic environment further illustrated its considerable potential for practical application.

  20. Development of a Supported Emulsion Liquid Membrane System for Propionic Acid Separation in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Li, Jin; Hu, Shih-Yao B.; Wiencek, John M.

    2001-01-01

    Perstractive fermentation is a good way to increase the productivity of bioreactors. Using Propionibacteria as the model system, the feasibility of using supported emulsion liquid membrane (SELM) for perstractive fermentation is assessed in this study. Five industrial solvents were considered as the solvent for preparing the SELM. The more polar a solvent is, the higher the partition coefficient. However, toxicity of a solvent also increases with its polarity. CO-1055 (industrial decanol/octanol blend) has the highest partition coefficient toward propionic acid among the solvents that has no molecular toxicity toward Propionibacteria. A preliminary extraction study was conducted using tetradecane as solvent in a hydrophobic hollow fiber contactor. The result confirmed that SELM eliminates the equilibrium limitation of conventional liquid-liquid extraction, and allows the use of a non-toxic solvent with low partition coefficient.

  1. Thermosyntropha lipolytica gen. nov., sp. nov., a lipolytic, anaerobic, alkalitolerant, thermophilic bacterium utilizing short- and long-chain fatty acids in syntrophic coculture with a methanogenic archaeum.

    PubMed

    Svetlitshnyi, V; Rainey, F; Wiegel, J

    1996-10-01

    Three strains of an anaerobic thermophilic organoheterotrophic lipolytic alkalitolerant bacterium, Thermosyntropha lipolytica gen. nov., sp. nov. (type strain JW/VS-265T; DSM 11003), were isolated from alkaline hot springs of Lake Bogoria (Kenya). The cells were nonmotile, non-spore forming, straight or slightly curved rods. At 60 degrees C the pH range for growth determined at 25 degrees C [pH25 degrees C] was 7.15 to 9.5, with an optimum between 8.1 and 8.9 (pH60 degrees C of 7.6 and 8.1). At a pH25 degrees C of 8.5 the temperature range for growth was from 52 to 70 degrees C, with an optimum between 60 and 66 degrees C. The shortest doubling time was around 1 h. In pure culture the bacterium grew in a mineral base medium supplemented with yeast extract, tryptone, Casamino Acids, betaine, and crotonate as carbon sources, producing acetate as a major product and constitutively a lipase. During growth in the presence of olive oil, free long-chain fatty acids were accumulated in the medium but the pure culture could not utilize olive oil, triacylglycerols, short- and long-chain fatty acids, and glycerol for growth. In syntrophic coculture (Methanobacterium strain JW/VS-M29) the lipolytic bacteria grew on triacylglycerols and linear saturated and unsaturated fatty acids with 4 to 18 carbon atoms, but glycerol was not utilized. Fatty acids with even numbers of carbon atoms were degraded to acetate and methane, while from odd-numbered fatty acids 1 mol of propionate per mol of fatty acid was additionally formed. 16S rDNA sequence analysis identified Syntrophospora and Syntrophomonas spp. as closest phylogenetic neighbors.

  2. Growth condition and bacterial community for maximum hydrolysis of suspended organic materials in anaerobic digestion of food waste-recycling wastewater.

    PubMed

    Kim, Man Deok; Song, Minkyung; Jo, Minho; Shin, Seung Gu; Khim, Jee Hyeong; Hwang, Seokhwan

    2010-02-01

    This paper reports the effects of changing pH (5-7) and temperature (T, 40-60 degrees C) on the efficiencies of bacterial hydrolysis of suspended organic matter (SOM) in wastewater from food waste recycling (FWR) and the changes in the bacterial community responsible for this hydrolysis. Maximum hydrolysis efficiency (i.e., 50.5% reduction of volatile suspended solids) was predicted to occur at pH 5.7 and T = 44.5 degrees C. Changes in short-chain volatile organic acid profiles and in acidogenic bacterial communities were investigated under these conditions. Propionic and butyric acids concentrations increased rapidly during the first 2 days of incubation. Several band sequences consistent with Clostridium spp. were detected using denaturing gel gradient electrophoresis. Clostridium thermopalmarium and Clostridium novyi seemed to contribute to butyric acid production during the first 1.5 days of acidification of FWR wastewater, and C. thermopalmarium was a major butyric acid producer afterward. C. novyi was an important propionic acid producer. These two species appear to be important contributors to hydrolysis of SOM in the wastewater. Other acidogenic anaerobes, Aeromonas sharmana, Bacillus coagulans, and Pseudomonas plecoglossicida, were also indentified.

  3. Microorganisms for producing organic acids

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

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  4. Microorganisms for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  5. Effect of Substrate Conversion on Performance of Microbial Fuel Cells and Anodic Microbial Communities.

    PubMed

    Zhao, Yang-Guo; Zhang, Yi; She, Zonglian; Shi, Yue; Wang, Min; Gao, Mengchun; Guo, Liang

    2017-09-01

    Performance of microbial fuel cells (MFCs) was monitored during the influent nutrient change from lactate to glucose/acetate/propionate and then to lactate. Meanwhile, anodic microbial communities were characterized by culture-independent molecular biotechnologies. Results showed MFC performance recovered rapidly when the lactate was replaced by one of its metabolic intermediates acetate, while it needed a longer time to recover if lactate substrate was converted to glucose/propionate or acetate to lactate. Secondary lactate feed enhanced the enrichment of bacterial populations dominating in first lactate feed. Electricity-producing bacteria, Geobacter spp., and beneficial helpers, Anaeromusa spp. and Pseudomonas spp., revived from a low abundance as lactate secondary supply, but microbial communities were hard to achieve former profiles in structure and composition. Hence, microbial community profiles tended to recover when outside environmental condition were restored. Different substrates selected unique functional microbial populations.

  6. Fermentable soluble fibres spare amino acids in healthy dogs fed a low-protein diet.

    PubMed

    Wambacq, Wendy; Rybachuk, Galena; Jeusette, Isabelle; Rochus, Kristel; Wuyts, Brigitte; Fievez, Veerle; Nguyen, Patrick; Hesta, Myriam

    2016-06-28

    Research in cats has shown that increased fermentation-derived propionic acid and its metabolites can be used as alternative substrates for gluconeogenesis, thus sparing amino acids for other purposes. This amino acid sparing effect could be of particular interest in patients with kidney or liver disease, where this could reduce the kidneys'/liver's burden of N-waste removal. Since dogs are known to have a different metabolism than the obligatory carnivorous cat, the main objective of this study was to assess the possibility of altering amino acid metabolism through intestinal fermentation in healthy dogs. This was studied by supplementing a low-protein diet with fermentable fibres, hereby providing an initial model for future studies in dogs suffering from renal/liver disease. Eight healthy dogs were randomly assigned to one of two treatment groups: sugar beet pulp and guar gum mix (SF: soluble fibre, estimated to mainly stimulate propionic acid production) or cellulose (IF: insoluble fibre). Treatments were incorporated into a low-protein (17 %) extruded dry diet in amounts to obtain similar total dietary fibre (TDF) contents for both diets (9.4 % and 8.2 % for the SF and IF diet, respectively) and were tested in a 4-week crossover feeding trial. Apparent faecal nitrogen digestibility and post-prandial fermentation metabolites in faeces and plasma were evaluated. Dogs fed the SF diet showed significantly higher faecal excretion of acetic and propionic acid, resulting in a higher total SCFA excretion compared to IF. SF affected the three to six-hour postprandial plasma acylcarnitine profile by significantly increasing AUC of acetyl-, propionyl-, butyryl- + isobutyryl-, 3-OH-butyryl-, 3-OH-isovaleryl- and malonyl-L-carnitine. Moreover, the amino acid plasma profile at that time was modified as leucine + isoleucine concentrations were significantly increased by SF, and a similar trend for phenylalanine and tyrosine's AUC was found. These results indicate that guar gum and sugar beet pulp supplementation diminishes postprandial use of amino acids favoring instead the use of short-chain fatty acids as substrate for the tricarboxylic acid (TCA) cycle. Further research is warranted to investigate the amino acid sparing effect of fermentable fibres in dogs with kidney/liver disease.

  7. Dynamics of putative sex pheromone components during heat periods in estrus-induced cows.

    PubMed

    Mozūraitis, R; Kutra, J; Borg-Karlson, A-K; Būda, V

    2017-09-01

    Determination of the optimal insemination time in dairy cows is vital for fertilization success and is a challenging task due to silent or weak signs of estrus shown by some cows. This can be overcome by combining several estrus detection methods, leading to higher detection rates. However, an efficient, noninvasive method for detecting estrus in cows is still needed. Chemical cues released by the cow during estrus have been proposed to have pheromonal properties and signal readiness to mate to the bull. Such cues could be used in an industrial setting to detect cows in estrus. However, no conclusive published data show temporal changes in putative sex pheromone levels during estrus. The goal of this study was to determine the temporal pattern of putative sex pheromone components during estrus and to assess the reproducibility of changes in pheromone concentration with respect to ovulation time. Two injections of the hormone PGF 2α were administered over a 2-wk interval to induce and synchronize the estrous cycles of 6 Holstein cows. The precise time of ovulation was determined by means of an ultrasound technique, and estrus was determined by visual observation. Using solid-phase microextraction gas chromatography-mass spectrometry techniques, we showed that acetic and propionic acids, which have been proposed to be putative sex pheromone components in cows, were present in the headspaces of all estrous and diestrous fecal samples, whereas 1-iodoundecane was not detected by solid-phase microextraction or by solvent extraction with diethyl ether. Low levels of acids were observed until 1 d before ovulation, at which point their concentrations increased, peaking around 0.5 d before ovulation. The application of labeled synthetic standards revealed that during the peak of release, 36 ± 8 ng (average ± SD) of acetic acid and 10 ± 3 ng of propionic acid were present in 0.5-g samples of estrous-phase fecal matter compared with 19 ± 5 and 2.3 ± 1 ng of acetic and propionic acids, respectively, in the control diestrous samples. After the peak, the amounts of the compounds decreased sharply to match those of the control samples and afterward returned to the baseline readings. This decrease in the amounts of putative pheromone components was registered about 12 h before ovulation, indicating that acetic and propionic acids could be used as biomarkers for the electronic detection of ovulation. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. Nasal retention of budesonide and fluticasone in man: Formation of airway mucosal budesonide-esters in vivo

    PubMed Central

    Petersen, Hannes; Kullberg, Annika; Edsbäcker, Staffan; Greiff, Lennart

    2001-01-01

    Aims The efficacy of topical glucocorticosteroids in rhinitis and asthma is likely to depend on drug retention in the airway mucosa. With fluticasone propionate, retention may be achieved exclusively by lipophilicity, whereas for budesonide an additional possibility may be provided by its ability to form fatty acid esters in the airway mucosa that release the active drug. The aim of the present study was to determine the nasal mucosal retention of budesonide and fluticasone propionate, and the occurrence of budesonide-esters (budesonide-oleate, budesonide-palmitate) in the nasal mucosa. Methods In the present study, involving 24 healthy subjects, we have examined nasal mucosal drug retention of single doses of topical budesonide (256 µg) and fluticasone propionate (200 µg). Treatments were given consecutively and the administration sequence was randomised. Subjects were randomised into four parallel groups and two nasal biopsies were taken from each subject, i.e. before and at 2 h, at 2 and 6 h, at 6 and 24 h, or before and at 24 h after drug administration, resulting in 12 biopsies/time point. The measurement of unesterified budesonide, budesonide-oleate, budesonide-palmitate, and fluticasone propionate was based on microwave extraction procedures combined with liquid-chromatography/tandem mass-spectrometry. Results Neither of the analytes was detected in samples taken before glucocorticosteroid administration. After administration, unesterified budesonide, budesonide-esters, and fluticasone propionate were detected in the tissue from 23, 20, and 19 subjects, respectively. The mean tissue levels of budesonide at 2 and 6 h were 1051 and 176 pmol g−1; the mean levels of fluticasone propionate at these time points were 237 and 10 pmol g−1. The dose-corrected budesonide/fluticasone propionate tissue concentration ratios were 3.5 (P = 0.07) and 13.7 (P < 0.0002), respectively. At 24 h, budesonide and fluticasone propionate were detected in 8/12 and 3/12 of the biopsies, respectively. Conclusions The present study demonstrates the formation of budesonide-esters in the human nasal mucosa in vivo, and that budesonide is retained in the nasal mucosa to a greater extent than fluticasone propionate. It is suggested that the formation of budesonide-esters and their subsequent release of budesonide contributes to an extended retention of budesonide in the airway mucosa. PMID:11259988

  9. L-rhamnose as a source of colonic propionate inhibits insulin secretion but does not influence measures of appetite or food intake.

    PubMed

    Darzi, Julia; Frost, Gary S; Swann, Jonathan R; Costabile, Adele; Robertson, M Denise

    2016-03-01

    Activation of free fatty acid receptor (FFAR)2 and FFAR3 via colonic short-chain fatty acids, particularly propionate, are postulated to explain observed inverse associations between dietary fiber intake and body weight. Propionate is reported as the predominant colonic fermentation product from l-rhamnose, a natural monosaccharide that resists digestion and absorption reaching the colon intact, while effects of long-chain inulin on appetite have not been extensively investigated. In this single-blind randomized crossover study, healthy unrestrained eaters (n = 13) ingested 25.5 g/d l-rhamnose, 22.4 g/d inulin or no supplement (control) alongside a standardized breakfast and lunch, following a 6-d run-in to investigate if appetite was inhibited. Postprandial qualitative appetite, breath hydrogen, and plasma glucose, insulin, triglycerides and non-esterified fatty acids were assessed for 420 min, then an ad libitum meal was provided. Significant treatment x time effects were found for postprandial insulin (P = 0.009) and non-esterified fatty acids (P = 0.046) with a significantly lower insulin response for l-rhamnose (P = 0.023) than control. No differences between treatments were found for quantitative and qualitative appetite measures, although significant treatment x time effects for meal desire (P = 0.008) and desire to eat sweet (P = 0.036) were found. Breath hydrogen was significantly higher with inulin (P = 0.001) and l-rhamnose (P = 0.009) than control, indicating colonic fermentation. These findings suggest l-rhamnose may inhibit postprandial insulin secretion, however neither l-rhamnose or inulin influenced appetite. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Study of benzoate, propionate, and sorbate salts as mould spoilage inhibitors on intermediate moisture bakery products of low pH (4.5-5.5).

    PubMed

    Guynot, M E; Ramos, A J; Sanchis, V; Marín, S

    2005-05-25

    A hurdle technology approach has been applied to control common mold species causing spoilage of intermediate moisture bakery products (Eurotium spp., Aspergillus spp., and Penicillium corylophilum), growing on a fermented bakery product analogue (FBPA). The factors studied included a combination of different levels of weak acid preservatives (potassium sorbate, calcium propionate, and sodium benzoate; 0-0.3%), pH (4.5-5.5), and water activity (a(w); 0.80-0.90). Potassium sorbate was found to be the most effective in preventing fungal spoilage of this kind of products at the maximum concentration tested (0.3%) regardless of a(w). The same concentration of calcium propionate and sodium benzoate was effective only at low a(w) levels. On the other hand, potassium sorbate activity was slightly reduced at pH 5.5, the 0.3% being only effective at 0.80 a(w). These findings indicate that potassium sorbate may be a suitable preserving agent to inhibit deterioration of a FBPA of slightly acidic pH (near 4.5) by xerophilic fungi. Further studies have to be done in order to adjust the minimal inhibitory concentration necessary to obtain a product with the required shelf life.

  11. Self-interrupted synthesis of sterically hindered aliphatic polyamide dendrimers

    PubMed Central

    Jishkariani, Davit; Timsina, Yam N.; Grama, Silvia; Gillani, Syeda S.; Divar, Masoumeh; Yadavalli, Srujana S.; Moussodia, Ralph-Olivier; Leowanawat, Pawaret; Berrios Camacho, Angely M.; Walter, Ricardo; Goulian, Mark; Klein, Michael L.; Percec, Virgil

    2017-01-01

    2,2-Bis(azidomethyl)propionic acid was prepared in four steps and 85% yield from the commercially available 2,2-bis(hydroxymethyl)propionic acid and used as the starting building block for the divergent, convergent, and double-stage convergent–divergent iterative methods for the synthesis of dendrimers and dendrons containing ethylenediamine (EDA), piperazine (PPZ), and methyl 2,2-bis(aminomethyl)propionate (COOMe) cores. These cores have the same multiplicity but different conformations. A diversity of synthetic methods were used for the synthesis of dendrimers and dendrons. Regardless of the method used, a self-interruption of the synthesis was observed at generation 4 for the dendrimer with an EDA core and at generation 5 for the one with a PPZ core, whereas for the COOMe core, self-interruption was observed at generation 6 dendron, which is equivalent to generation 5 dendrimer. Molecular modeling and molecular-dynamics simulations demonstrated that the observed self-interruption is determined by the backfolding of the azide groups at the periphery of the dendrimer. The latter conformation inhibits completely the heterogeneous hydrogenation of the azide groups catalyzed by 10% Pd/carbon as well as homogeneous hydrogenation by the Staudinger method. These self-terminated polyamide dendrimers are enzymatically and hydrolytically stable and also exhibit antimicrobial activity. Thus, these nanoscale constructs open avenues for biomedical applications. PMID:28270599

  12. The function of probiotics on the treatment of ventilator-associated pneumonia (VAP): facts and gaps.

    PubMed

    Karacaer, Feride; Hamed, Imen; Özogul, Fatih; Glew, Robert H; Özcengiz, Dilek

    2017-09-01

    Probiotics have been used for centuries in making fermented dairy products. The health benefits related to probiotics consumption are well recognized and they are generally regarded as safe (GRAS). Their therapeutic effects are due to the production of a variety of antimicrobial compounds, such as short-chain fatty acids, organic acids (such as lactic, acetic, formic, propionic and butyric acids), ethanol, hydrogen peroxide and bacteriocins. Ventilator-associated pneumonia (VAP) is a nosocomial infection associated with high mortality in intensive care units. VAP can result from endotracheal intubation and mechanical ventilation. These interventions increase the risk of infection as patients lose the natural barrier between the oropharynx and the trachea, which in turn facilitates the entry of pathogens through the aspiration of oropharyngeal secretions containing bacteria into the lung. In order to prevent this, probiotics have been used extensively against VAP. This review is an update containing information extracted from recent studies on the use of probiotics to treat VAP. In addition, probiotic safety, the therapeutic properties of probiotics, the probiotic strains used and the action of the probiotics mechanism are reviewed. Furthermore, the therapeutic effects of probiotic treatment procedures for VAP are compared to those of antibiotics. Finally, the influences of bacteriocin on the growth of human pathogens, and the side-effects and limitations of using probiotics for the treatment of VAP are addressed.

  13. Enhanced biological phosphorus removal in a sequencing batch reactor using propionate as the sole carbon source.

    PubMed

    Pijuan, M; Saunders, A M; Guisasola, A; Baeza, J A; Casas, C; Blackall, L L

    2004-01-05

    An enhanced biological phosphorus removal (EBPR) system was developed in a sequencing batch reactor (SBR) using propionate as the sole carbon source. The microbial community was followed using fluorescence in situ hybridization (FISH) techniques and Candidatus 'Accumulibacter phosphatis' were quantified from the start up of the reactor until steady state. A series of SBR cycle studies was performed when 55% of the SBR biomass was Accumulibacter, a confirmed polyphosphate accumulating organism (PAO) and when Candidatus 'Competibacter phosphatis', a confirmed glycogen-accumulating organism (GAO), was essentially undetectable. These experiments evaluated two different carbon sources (propionate and acetate), and in every case, two different P-release rates were detected. The highest rate took place while there was volatile fatty acid (VFA) in the mixed liquor, and after the VFA was depleted a second P-release rate was observed. This second rate was very similar to the one detected in experiments performed without added VFA.A kinetic and stoichiometric model developed as a modification of Activated Sludge Model 2 (ASM2) including glycogen economy, was fitted to the experimental profiles. The validation and calibration of this model was carried out with the cycle study experiments performed using both VFAs. The effect of pH from 6.5 to 8.0 on anaerobic P-release and VFA-uptake and aerobic P-uptake was also studied using propionate. The optimal overall working pH was around 7.5. This is the first study of the microbial community involved in EBPR developed with propionate as a sole carbon source along with detailed process performance investigations of the propionate-utilizing PAOs. Copyright 2003 Wiley Periodicals, Inc.

  14. Biological activity of some derivatives of β-cyclodextrin.

    PubMed

    Batalova, T A; Dorovskich, V A; Kurochkina, G I; Grachev, M K; Plastinin, M L; Sergievich, A A

    2011-10-01

    New compounds of β-cyclodextrin containing covalently bound (conjugated) residues of acetylsalicylic and 1-(4-isobutylphenyl)-propionic acids were synthesized in the reaction of chlorides of the corresponding acids with β-cyclodextrin. We studied antiplatelet and antiphlogistic properties of these substances. It was shown that new compounds are comparable and in some cases are superior to the reference drugs acetylsalicylic acid and ibuprofen by anti-inflammatory and antiaggregant activities.

  15. Photochemical reaction of 2-(3-benzoylphenyl)propionic acid (ketoprofen) with basic amino acids and dipeptides.

    PubMed

    Suzuki, Tadashi; Shinoda, Mio; Osanai, Yohei; Isozaki, Tasuku

    2013-08-22

    Photoreaction of 2-(3-benzoylphenyl)propionic acid (ketoprofen, KP) with basic amino acids (histidine, lysine, and arginine) and dipeptides (carnosine and anserine) including a histidine moiety in phosphate buffer solution (pH 7.4) has been investigated with transient absorption spectroscopy. With UV irradiation KP(-) gave rise to a carbanion through a decarboxylation reaction, and the carbanion easily abstracted a proton from the surrounding molecule to yield a 3-ethylbenzophenone ketyl biradical (EBPH). The dipeptides as well as the basic amino acids were found to accelerate the proton transfer reaction whereas alanine and glycine had no effect on the reaction, revealing that these amino acids having a protonated side chain act as a proton donor. The formation quantum yield of EBPH was estimated to be fairly large by means of an actinometrical method with benzophenone, and the bimolecular reaction rate constant for the proton transfer between the carbanion and the protonated basic amino acids or the protonated dipeptides was successfully determined. It has become apparent that the bimolecular reaction rate constant for the proton transfer depended on the acid dissociation constant for the side chain of the amino acids for the first time. This reaction mechanism was interpreted by difference of the heat of reaction for each basic amino acid based on the thermodynamical consideration. These results strongly suggest that the side chain of the basic amino acid residue in protein should play an important role for photochemistry of KP in vivo.

  16. An evaluation of the effectiveness of a chemical additive based on sodium benzoate, potassium sorbate, and sodium nitrite on the fermentation and aerobic stability of corn silage.

    PubMed

    Kung, Limin; Smith, Megan L; Benjamim da Silva, Erica; Windle, Michelle C; da Silva, Thiago C; Polukis, Stephanie A

    2018-04-11

    We evaluated the effectiveness of an additive comprising sodium benzoate, potassium sorbate, and sodium nitrite (SSL) as active ingredients for its ability to improve the aerobic stability of corn silages made in North America. In experiment 1, treatment with SSL (1.5 and 2.0 L/t) on whole-plant corn (WPC) was compared with treatment with an additive containing buffered propionic acid and citric acid (BPA; 2 L/t) on corn harvested at 32 and 38% DM and ensiled for 120 d. Silage treated with BPA was higher in ammonia-N and propionic acid relative to other treatments. Treatments with all of the additives had numerically, but not statistically, fewer yeasts compared with untreated silage. Both application rates of SSL resulted in lower concentrations of ethanol compared with untreated and BPA silages. Treatment with BPA improved the aerobic stability of silages compared with untreated silage, but the effect from SSL was markedly greater. In experiment 2, WPC was untreated or treated with 2 or 3 L of SSL/t or a microbial inoculant containing Enterococcus faecium M74, Lactobacillus plantarum CH6072, and Lactobacillus buchneri LN1819 (final total lactic acid bacteria application rate of 150,000 cfu/g of fresh forage). Silages were air stressed for 24 h at 28 and 42 d of storage and ensiled for 49 d before opening. Inoculation had no effect on acid end products, ethanol, number of yeasts, or aerobic stability compared with other treatments. Treatment with SSL decreased the amount of ethanol, had no effect on number of yeasts, and improved aerobic stability in a dose-dependent manner compared with other treatments. In experiment 3, WPC was untreated or treated with 2 L of SSL/t and ensiled for 5, 15, and 30 d. Treatment with SSL resulted in silage with fewer yeasts and lower concentrations of ethanol after all times of ensiling compared with untreated silage. In addition, SSL improved aerobic stability after each period of ensiling, but the effect was more at 15 and 30 d compared with 5 d of storage. Treating WPC with SSL can improve the aerobic stability of corn silage made in North America, and the effect can be observed as soon as 5 d after ensiling. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Feeding ecology of Ammothella longipes (Arthropoda: Pycnogonida) in the Mediterranean Sea: A fatty acid biomarker approach

    NASA Astrophysics Data System (ADS)

    Soler-Membrives, Anna; Rossi, Sergio; Munilla, Tomás

    2011-05-01

    Fatty acid analysis has proved valuable in determining seasonal trophic links and the feeding behavior in organisms in which these diet and trophic links cannot be inferred from stomach content analyses. Seasonal variations in total free fatty acid content (TFFA) and fatty acid composition of seston (<250 μm), the brown macroalgae Stypocaulon spp., polychaetes (Nereididae) and the pycnogonid Ammothella longipes have been used to establish their trophic links, with particular focus on seasonality and feeding ecology of A. longipes. Samples were collected in a coastal environment (NW Mediterranean Sea) at 7-10 m depth, in five different periods (August and October 2008, February, June and September 2009). Seston and Stypocaulon spp. samples did not show significant seasonal variations in TFFA content, while nereids showed a significant variation. Analysis of fatty acid profile showed high similarities of fatty acid composition between seston and Stypocaulon spp. Nereids were closer to seston and Stypocaulon spp. than A. longipes, which seemed to follow a seasonal trend. The results of this study reveal that A. longipes may change its feeding behavior depending on the season and available food. This pycnogonid species appears to be carnivore during spring and early summer but seems to feed on detritus when availability of prey diminishes during winter. Notable high amounts of odd-chain fatty acids are found in summer-autumn for this species, which may come from bacteria acquired from the detrital diet or from de novo biosynthesis from propionate. The results obtained provide new and valuable data on the understudied feeding biology of pycnogonids in general, and contribute to the understanding of their functioning of Mediterranean shallow oligotrophic systems and their trophic links.

  18. Dietary α-cyclodextrin modifies gut microbiota and reduces fat accumulation in high-fat-diet-fed obese mice.

    PubMed

    Nihei, Nanako; Okamoto, Hinako; Furune, Takahiro; Ikuta, Naoko; Sasaki, Kengo; Rimbach, Gerald; Yoshikawa, Yutaka; Terao, Keiji

    2018-05-07

    We investigated the effect of α-cyclodextrin (α-CD) on the bacterial populations of gut microbiota, production of organic acids, and short-chain fatty acids (SCFAs), and lipid metabolism in obese mice induced by feeding a high-fat diet (HFD). Male C57BL/6J mice were assigned to three diet groups: normal diet (ND) (5% [w/w] fat), HFD (35% [w/w] fat), and HFD (35% [w/w] fat) + 5.5% (w/w) α-CD for 16 weeks. Increases in body and epididymal adipose tissue weights were observed in the HFD group compared with the ND group, which were attenuated in the HFD+α-CD group. The supplementation of α-CD increased the total number of bacteria, Bacteroides, Bifidobacterium, and Lactobacillus that were decreased in gut microbiota of mice by feeding the HFD. Importantly, α-CD administration increased the concentrations of lactic acid and SCFAs, such as acetic, propionic, and butyric acids, and decreased glucose concentrations in cecal contents. Furthermore, supplementation of α-CD upregulated the gene expression of peroxisome proliferator-activated receptor (PPAR)γ involved in adipocyte differentiation and PPARα involved in energy expenditure and downregulated that of sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase involved in fatty acid and triglyceride synthesis in adipose tissue. This study revealed that the alteration in gut microbiota and increased production of lactic acid and SCFAs by supplementation of α-CD have beneficial antiobesity effects via modulating the expression of genes related to lipid metabolism, indicating a prebiotic property of α-CD. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

  19. Microbial populations and fermentation profiles in rumen liquid and solids of Holstein cows respond differently to dietary barley processing.

    PubMed

    Metzler-Zebeli, B U; Khol-Parisini, A; Gruber, L; Zebeli, Q

    2015-12-01

    To evaluate the effects of treating barley grain with lactic acid (LA) and heat on postprandial dynamics of 19 microbial taxa and fermentation in the rumen of dairy cows. This study was designed as a double 3 × 3 Latin square with six rumen-cannulated cows and three diets either containing untreated control barley or barley treated with 1% LA and 1% LA and heat (LAH, 55°C). Microbial populations, pH and volatile fatty acids were assessed in rumen liquid and solids during the postprandial period. Propionate increased and butyrate decreased in rumen solids of cows fed LA and LAH treated barley compared to the control barley. The LA but not LAH treatment depressed Fibrobacter succinogenes in rumen liquid and solids, whereas the opposite effect was observed for Ruminococcus albus in both fractions and Ruminococcus flavefaciens in rumen solids. LA promoted Ruminobacter amylophilus with the effect being more pronounced with LAH. The Lactobacillus group and Megasphaera elsdenii increased in both fractions with LA but not with LAH. LA and LAH treatment of barley differently altered ruminal abundance of certain bacterial taxa and fungi and increased propionate fermentation in rumen solids, whereby LA and LAH effects were consistent and mostly independent of the rumen fraction and time after barley feeding. Results provided evidence that LA and LAH treatment of barley can enhance rumen propionate fermentation without adversely affecting rumen pH. As propionate is the major contributor to gluconeogenesis in ruminants, the present barley treatment may have practical application to enhance energy supply in dairy cows. © 2015 The Society for Applied Microbiology.

  20. Choline acetyltransferase and organic cation transporters are responsible for synthesis and propionate-induced release of acetylcholine in colon epithelium.

    PubMed

    Bader, Sandra; Klein, Jochen; Diener, Martin

    2014-06-15

    Acetylcholine is not only a neurotransmitter, but is found in a variety of non-neuronal cells. For example, the enzyme choline acetyltransferase (ChAT), catalyzing acetylcholine synthesis, is expressed by the colonic epithelium of different species. These cells release acetylcholine across the basolateral membrane after luminal exposure to propionate, a short-chain fatty acid. The functional consequence is the induction of chloride secretion, measurable as increase in short-circuit current (Isc) in Ussing chamber experiments. It is unclear how acetylcholine is produced and released by colonic epithelium. Therefore, the aim of the present study was the identification (on mRNA and protein level) and functional characterization (in Ussing chamber experiments combined with HPLC detection of acetylcholine) of transporters/enzymes in the cholinergic system of rat colonic epithelium. Immunohistochemical staining as well as RT-PCR revealed the expression of high-affinity choline transporter, ChAT, carnitine acetyltransferase (CarAT), vesicular acetylcholine transporter (VAChT), and organic cation transporters (OCT 1, 2, 3) in colonic epithelium. In contrast to blockade of ChAT with bromoacetylcholine, inhibition of CarAT with mildronate did not inhibit the propionate-induced increase in Isc, suggesting a predominant synthesis of epithelial acetylcholine by ChAT. Although being expressed, blockade of VAChT with vesamicol was ineffective, whereas inhibition of OCTs with omeprazole and corticosterone inhibited propionate-induced Isc and the release of acetylcholine into the basolateral compartment. In summary, OCTs seem to be involved in regulated acetylcholine release by colonic epithelium, which is assumed to be involved in chemosensing of luminal short-chain fatty acids by the intestinal epithelium. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Preparation of Nickel Aluminum-Manganese Spinel Oxides Ni xAl 1- xMn 2O 4 for Oxygen Electrocatalysis in Alkaline Medium: Comparison of Properties Stemming from Different Preparation Methods

    NASA Astrophysics Data System (ADS)

    Ponce, Jilberto; Ríos, Edmundo; Rehspringer, Jean-Luc; Poillerat, Gérard; Chartier, Pierre; Gautier, Juan Luis

    1999-06-01

    Two different procedures were used to prepare spinel-type NixAl1-xMn2O4 (0≤x≤1) compounds to study the effects of solid state properties of mixed oxides on their electrocatalytic properties. The oxalic route, coprecipitation of metal oxalates dissolved in propanol or ethanol, and the propionic route, hydrolysis of metal carboxylates in propionic acid, have been used. In both routes, thermal decomposition produces the corresponding oxides. X-ray diffraction patterns showed that the oxides crystallize in a cubic spinel phase with a unit cell parameter a that increases as aluminum is replaced by nickel. At low x values, compounds prepared by the propionic route showed a larger variation for parameter a than compounds prepared by the oxalic route, probably due to oxygen stoichiometric deficiency. This effect was estimated from the tetrahedral force constant (kt) values, which showed a fast decrease as x varied from 0 to 1. Electrical conductivity, conduction activation energy, hole mobility, and pHz of oxides prepared by the propionic route were also higher than those from oxides prepared by the oxalic route. Crystallinity grade and particle size were nearly 50‧ higher in propionic-route samples than in oxalic-route samples. The apparent and real electrocatalytic activities of both types of oxides were compared for O2 evolution.

  2. Molecular analysis of the biomass of a fluidized bed reactor treating synthetic vinasse at anaerobic and micro-aerobic conditions.

    PubMed

    Rodríguez, Elisa; Lopes, Alexandre; Fdz-Polanco, María; Stams, Alfons J M; García-Encina, Pedro A

    2012-03-01

    The microbial communities (Bacteria and Archaea) established in an anaerobic fluidized bed reactor used to treat synthetic vinasse (betaine, glucose, acetate, propionate, and butyrate) were characterized by denaturing gradient gel electrophoresis (DGGE) and phylogenetic analysis. This study was focused on the competitive and syntrophic interactions between the different microbial groups at varying influent substrate to sulfate ratios of 8, 4, and 2 and anaerobic or micro-aerobic conditions. Acetogens detected along the anaerobic phases at substrate to sulfate ratios of 8 and 4 seemed to be mainly involved in the fermentation of glucose and betaine, but they were substituted by other sugar or betaine degraders after oxygen application. Typical fatty acid degraders that grow in syntrophy with methanogens were not detected during the entire reactor run. Likely, sugar and betaine degraders outnumbered them in the DGGE analysis. The detected sulfate-reducing bacteria (SRB) belonged to the hydrogen-utilizing Desulfovibrio. The introduction of oxygen led to the formation of elemental sulfur (S(0)) and probably other sulfur compounds by sulfide-oxidizing bacteria (γ-Proteobacteria). It is likely that the sulfur intermediates produced from sulfide oxidation were used by SRB and other microorganisms as electron acceptors, as was supported by the detection of the sulfur respiring Wolinella succinogenes. Within the Archaea population, members of Methanomethylovorans and Methanosaeta were detected throughout the entire reactor operation. Hydrogenotrophic methanogens mainly belonging to the genus Methanobacterium were detected at the highest substrate to sulfate ratio but rapidly disappeared by increasing the sulfate concentration.

  3. Identification of a probiotic bacteria-derived activator of the aryl hydrocarbon receptor that inhibits colitis.

    PubMed

    Fukumoto, Suguru; Toshimitsu, Takayuki; Matsuoka, Shuji; Maruyama, Atsushi; Oh-Oka, Kyoko; Takamura, Takeyuki; Nakamura, Yuki; Ishimaru, Kayoko; Fujii-Kuriyama, Yoshiaki; Ikegami, Shuji; Itou, Hiroyuki; Nakao, Atsuhito

    2014-01-01

    The aryl hydrocarbon receptor (AhR) recognizes environmental xenobiotics and is originally thought to be involved in the metabolism (detoxification) of the substances. Recently, AhR is highlighted as an important regulator of inflammation. Notably, accumulating evidence suggests that activation of the AhR suppresses inflammatory bowel diseases (IBDs). Therefore, non-toxic AhR activators become attractive drug candidates for IBD. This study identified 1,4-dihydroxy-2-naphthoic acid (DHNA), a precursor of menaquinone (vitamin K2) abundantly produced by Propionibacterium freudenreichii ET-3 isolated from Swiss-type cheese, as an AhR activator. DHNA activated the AhR pathway in human intestinal epithelial cell line Caco2 cells and in the mouse intestine. Oral treatment of mice with DHNA induced anti-microbial proteins RegIIIβ and γ in the intestine, altered intestinal microbial flora and inhibited dextran sodium sulfate (DSS)-induced colitis, which recapitulated the phenotypes of AhR activation in the gut. As DHNA is commercially available in Japan as a prebiotic supplement without severe adverse effects, DHNA or its derivatives might become a promising drug candidate for IBD via AhR activation. The results also implicate that intestinal AhR might act not only as a sensor for xenobiotics in diet and water but also for commensal bacterial activity because DHNA is a precursor of vitamin K2 produced by vitamin K2-synthesizing commensal bacteria as well as propionic bacteria. Hence, DHNA might be a key bacterial metabolite in the host-microbe interaction to maintain intestinal microbial ecosystem.

  4. Neurite outgrowth of murine cerebellar granule cells can be enhanced by aniracetam with or without alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA).

    PubMed

    Fushiki, S; Matsumoto, K; Nagata, A

    1995-10-27

    To assess the neurotrophic effects of a nootropic drug, aniracetam, we studied neurite extension of mouse cerebellar granule cells in culture with low or with high K+ under different combinations of drugs and then immunohistochemically stained the cells with an antibody against L1, a neural cell adhesion molecule on cerebellar granule cells. Quantitative analyses using parameters of the total neurite length, maximal neurite length and number of branches disclosed that aniracetam, in the presence of high K+ and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA), significantly enhanced neurite extension of cultured granule neurons. Aniracetam alone also stimulated neurite extension of cerebellar granule cells at a longer period of culture with low K+ showing a bell-shaped dose response curve with maximal effects at 10 microM. Aniracetam may influence remodeling of the neural network after injury.

  5. Economic and environmental assessment of propionic acid production by fermentation using different renewable raw materials.

    PubMed

    Tufvesson, Pär; Ekman, Anna; Sardari, Roya R R; Engdahl, Kristina; Tufvesson, Linda

    2013-12-01

    Production of propionic acid by fermentation of glycerol as a renewable resource has been suggested as a means for developing an environmentally-friendly route for this commodity chemical. However, in order to quantify the environmental benefits, life cycle assessment of the production, including raw materials, fermentation, upstream and downstream processing is required. The economic viability of the process also needs to be analysed to make sure that any environmental savings can be realised. In this study an environmental and economic assessment from cradle-to-gate has been conducted. The study highlights the need for a highly efficient bioprocess in terms of product titre (more than 100g/L and productivity more than 2g/(L · h)) in order to be sustainable. The importance of the raw materials and energy production for operating the process to minimize emissions of greenhouse gases is also shown. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. The effect of dietary supplementation of salts of organic acid on production performance of laying hens

    PubMed Central

    Dahiya, Ravinder; Berwal, Raj Singh; Sihag, Sajjan; Patil, Chandrashekhar Santosh; Lalit

    2016-01-01

    Aim: An experiment was conducted to evaluate the effect of supplementing different levels of salts of organic acid in the laying hen’s diet on their production performance and egg quality parameters during a period of 16-week. Materials and Methods: A total of 140 white leghorn laying hens at 24 weeks of age were randomly distributed to seven dietary treatment groups, i.e. T1 (control), T2 (0.5% sodium-butyrate), T3 (1.0% sodium-butyrate), T4 (1.5% sodium-butyrate), T5 (0.5% calcium-propionate), T6 (1.0% calcium-propionate) and T7 (1.5% calcium-propionate) consisting of 5 replications of 4 birds each in each treatment and housed in individual cages from 24 to 40 weeks of age. Feed intake, percent hen-day egg production, egg weight, egg mass production, feed conversion ratio (FCR), and economics of supplementation of salts of organic acids in layers’ ration were evaluated. Results: The dietary supplementation of salts of organic acids did not significantly affect the feed intake (g/day/hen) and body weight gain (g). Different levels of supplementation significantly (p<0.05) improved production performance (percent hen-day egg production and egg mass production) as compared to control group. FCR in terms of feed intake (kg) per dozen eggs was lowest (1.83±0.05) in T4 and feed intake (kg) per kg egg mass was lowest (2.87±0.05) in T5 as comparison to control (T1) group. Salts of organic acids supplementation resulted in significant (p<0.05) improvement in FCR. Egg weight was significantly (p<0.05) increased at 0.5% level of salts of organic acids in the diet. The cumulative mean values of feed cost per dozen egg production were Rs. 44.14, 42.40, 42.85, 43.26, 42.57, 43.29 and 43.56 in treatment groups T1, T2, T3, T4, T5, T6 and T7, respectively, and reduction in feed cost per kg egg mass production for Rs. 0.52 and 0.99 in groups T2 and T5, respectively, in comparison to T1 group. Conclusions: It can be concluded that supplementation of salts of organic acids may improve persistency of lay, egg weight, and FCR. From economical point of view, egg production was more profitable at 0.5% level of sodium butyrate and 0.5% level of calcium propionate which reduced the feed cost per dozen eggs and per kg egg mass production without affecting the egg quality. PMID:28096625

  7. Green technology for conversion of food scraps to biodegradable thermoplastic polyhydroxyalkanoates.

    PubMed

    Du, Guocheng; Yu, Jian

    2002-12-15

    A new technology is developed and demonstrated that couples anaerobic digestion of food scraps with production of biodegradable thermoplastics, polyhydroxyalkanoates (PHAs). The food wastes were digested in an anaerobic reactor producing four major organic acids. The concentrations of acetic, propionic, butyric, and lactic acids reached 5.5, 1.8, 27.4, and 32.7 g/L, respectively. The fermentative acids were transferred through membranes via molecule diffusion into an air-bubbling reactor where the acids were utilized to produce PHAs in an enriched culture of Ralstonia eutropha. With a silicone rubber membrane, butyric acid and small amounts of acetic and propionic acids were transferred and used, producing a homopolymer PHA, poly(3-hydroxybutyrate). The dry cell weight and PHA content reached 11.3 g/L and 60.2% (w/w), respectively. With a dialysis membrane, the mass transfer rates of fermentative acids were enhanced, and the PHA production was significantly improved. The dry cell weight and its PHA content reached 22.7 g/L and 72.6% (w/w), respectively. The formed PHA was a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate (HV) with 2.8 mol % HV monomer unit. The polymer content (72.6% of dry cell mass) reported in this study is the highest one obtained from organic wastes and is comparable with the PHA content from pure glucose fermentation.

  8. Formation of fatty acids in photochemical conversions of saturated hydrocarbons

    NASA Technical Reports Server (NTRS)

    Telegina, T. A.; Pavlovskaya, T. Y.; Ladyzhenskaya, A. I.

    1977-01-01

    Abiogenic synthesis of fatty acids was studied in photochemical conversions of saturated hydrocarbons. It was shown that, in a hydrocarbon water CaCO3 suspension, the action of 254 nm UV rays caused the formation of fatty acids with a maximum number of carbon atoms in the chain not exceeding that in the initial hydrocarbon. Synthesis of acetic, propionic, butyric, valeric, caproic, enanthic and caprylic (in the case of octane) acids occurs in heptane water CaCO3 and octane water CaCO3 systems.

  9. Quantitative analysis of growth and volatile fatty acid production by the anaerobic ruminal bacterium Megasphaera elsdenii T81

    USDA-ARS?s Scientific Manuscript database

    Megaspheara elsdenii T81 grew on either DL-lactate or D-glucose at similar rates (0.85 per h), but displayed major differences in the fermentation of these substrates. Lactate was fermented at up to 210-mM concentration to yield acetic, propionic, butyric, and valeric acids. The bacterium was able t...

  10. Properties of Acetate Kinase Isozymes and a Branched-Chain Fatty Acid Kinase from a Spirochete

    PubMed Central

    Harwood, Caroline S.; Canale-Parola, Ercole

    1982-01-01

    Spirochete MA-2, which is anaerobic, ferments glucose, forming acetate as a major product. The spirochete also ferments (but does not utilize as growth substrates) small amounts of l-leucine, l-isoleucine, and l-valine, forming the branched-chain fatty acids isovalerate, 2-methylbutyrate, and isobutyrate, respectively, as end products. Energy generated through the fermentation of these amino acids is utilized to prolong cell survival under conditions of growth substrate starvation. A branched-chain fatty acid kinase and two acetate kinase isozymes were resolved from spirochete MA-2 cell extracts. Kinase activity was followed by measuring the formation of acyl phosphate from fatty acid and ATP. The branched-chain fatty acid kinase was active with isobutyrate, 2-methylbutyrate, isovalerate, butyrate, valerate, or propionate as a substrate but not with acetate as a substrate. The acetate kinase isozymes were active with acetate and propionate as substrates but not with longer-chain fatty acids as substrates. The acetate kinase isozymes and the branched-chain fatty acid kinase differed in nucleoside triphosphate and cation specificities. Each acetate kinase isozyme had an apparent molecular weight of approximately 125,000, whereas the branched-chain fatty acid kinase had a molecular weight of approximately 76,000. These results show that spirochete MA-2 synthesizes a branched-chain fatty acid kinase specific for leucine, isoleucine, and valine fermentation. It is likely that a phosphate branched-chain amino acids is also synthesized by spirochete MA-2. Thus, in spirochete MA-2, physiological mechanisms have evolved which serve specifically to generate maintenance energy from branched-chain amino acids. PMID:6288660

  11. Effects of nitrate addition to a diet on fermentation and microbial populations in the rumen of goats, with special reference to Selenomonas ruminantium having the ability to reduce nitrate and nitrite.

    PubMed

    Asanuma, Narito; Yokoyama, Shota; Hino, Tsuneo

    2015-04-01

    This study investigated the effects of dietary nitrate addition on ruminal fermentation characteristics and microbial populations in goats. The involvement of Selenomonas ruminantium in nitrate and nitrite reduction in the rumen was also examined. As the result of nitrate feeding, the total concentration of ruminal volatile fatty acids decreased, whereas the acetate : propionate ratio and the concentrations of ammonia and lactate increased. Populations of methanogens, protozoa and fungi, as estimated by real-time PCR, were greatly decreased as a result of nitrate inclusion in the diet. There was modest or little impact of nitrate on the populations of prevailing species or genus of bacteria in the rumen, whereas Streptococcus bovis and S. ruminantium significantly increased. Both the activities of nitrate reductase (NaR) and nitrite reductase (NiR) per total mass of ruminal bacteria were increased by nitrate feeding. Quantification of the genes encoding NaR and NiR by real-time PCR with primers specific for S. ruminantium showed that these genes were increased by feeding nitrate, suggesting that the growth of nitrate- and nitrite-reducing S. ruminantium is stimulated by nitrate addition. Thus, S. ruminantium is likely to play a major role in nitrate and nitrite reduction in the rumen. © 2014 Japanese Society of Animal Science.

  12. Hay preservation with propionic acid

    USDA-ARS?s Scientific Manuscript database

    Most hay producers are quite familiar with the problems associated with baling moist hays. Normally, these problems include spontaneous heating, increased evidence of mold, losses of dry matter (DM) during storage, poorer nutritive value, and (in extreme cases) spontaneous combustion. Numerous fact...

  13. In vitro characterisation of the fermentation profile and prebiotic capacity of gold-fleshed kiwifruit.

    PubMed

    Blatchford, P; Bentley-Hewitt, K L; Stoklosinski, H; McGhie, T; Gearry, R; Gibson, G; Ansell, J

    2015-01-01

    A new Actinidia chinensis gold-fleshed kiwifruit cultivar 'Zesy002' was tested to investigate whether it could positively modulate the composition of the human colonic microbiota. Digested Zesy002 kiwifruit was added to in vitro pH-controlled anaerobic batch fermenters that were inoculated with representative human faecal microbiota. Alterations to the gut microbial ecology were determined by 16S rRNA gene sequencing and metabolic end products were measured using gas chromatography and liquid chromatography - mass spectrometry. Results indicated a substantial shift in the composition of bacteria within the gut models caused by kiwifruit supplementation. Zesy002 supplemented microbiota had a significantly higher abundance of Bacteroides spp., Parabacteroides spp. and Bifidobacterium spp. after 48 h of fermentation compared with the start of the fermentation. Organic acids from kiwifruit were able to endure simulated gastrointestinal digestion and were detectable in the first 10 h of fermentation. The fermentable carbohydrates were converted to beneficial organic acids with a particular predilection for propionate production, corresponding with the rise in Bacteroides spp. and Parabacteroides spp. These results support the claim that Zesy002 kiwifruit non-digestible fractions can effect favourable changes to the human colonic microbial community and primary metabolites, and demonstrate a hitherto unknown effect of Zesy002 on colonic microbiota under in vitro conditions.

  14. Metatranscriptome analysis of the microbial fermentation of dietary milk proteins in the murine gut.

    PubMed

    Hugenholtz, Floor; Davids, Mark; Schwarz, Jessica; Müller, Michael; Tomé, Daniel; Schaap, Peter; Hooiveld, Guido J E J; Smidt, Hauke; Kleerebezem, Michiel

    2018-01-01

    Undigestible food ingredients are converted by the microbiota into a large range of metabolites, predominated by short chain fatty acids (SCFA). These microbial metabolites are subsequently available for absorption by the host mucosa and can serve as an energy source. Amino acids fermentation by the microbiota expands the spectrum of fermentation end-products beyond acetate, propionate and butyrate, to include in particular branched-SCFA. Here the long-term effects of high protein-diets on microbial community composition and functionality in mice were analyzed. Determinations of the microbiota composition using phylogenetic microarray (MITChip) technology were complemented with metatranscriptome and SCFA analyses to obtain insight in in situ expression of protein fermentation pathways and the phylogenetic groups involved. High protein diets led to increased luminal concentrations of branched-SCFA, in accordance with protein fermentation in the gut. Bacteria dominantly participating in protein catabolism belonged to the Lachnospiraceae, Erysipelotrichaceae and Clostridiaceae families in both normal- and high- protein diet regimes. This study identifies the microbial groups involved in protein catabolism in the intestine and underpins the value of in situ metatranscriptome analyses as an approach to decipher locally active metabolic networks and pathways as a function of the dietary regime, as well as the phylogeny of the microorganisms executing them.

  15. Using slaughterhouse waste in a biochemical-based biorefinery - results from pilot scale tests.

    PubMed

    Schwede, Sebastian; Thorin, Eva; Lindmark, Johan; Klintenberg, Patrik; Jääskeläinen, Ari; Suhonen, Anssi; Laatikainen, Reino; Hakalehto, Elias

    2017-05-01

    A novel biorefinery concept was piloted using protein-rich slaughterhouse waste, chicken manure and straw as feedstocks. The basic idea was to provide a proof of concept for the production of platform chemicals and biofuels from organic waste materials at non-septic conditions. The desired biochemical routes were 2,3-butanediol and acetone-butanol fermentation. The results showed that hydrolysis resulted only in low amounts of easily degradable carbohydrates. However, amino acids released from the protein-rich slaughterhouse waste were utilized and fermented by the bacteria in the process. Product formation was directed towards acidogenic compounds rather than solventogenic products due to increasing pH-value affected by ammonia release during amino acid fermentation. Hence, the process was not effective for 2,3-butanediol production, whereas butyrate, propionate, γ-aminobutyrate and valerate were predominantly produced. This offered fast means for converting tedious protein-rich waste mixtures into utilizable chemical goods. Furthermore, the residual liquid from the bioreactor showed significantly higher biogas production potential than the corresponding substrates. The combination of the biorefinery approach to produce chemicals and biofuels with anaerobic digestion of the residues to recover energy in form of methane and nutrients that can be utilized for animal feed production could be a feasible concept for organic waste utilization.

  16. Faecalibacterium prausnitzii subspecies-level dysbiosis in the human gut microbiome underlying atopic dermatitis.

    PubMed

    Song, Han; Yoo, Young; Hwang, Junghyun; Na, Yun-Cheol; Kim, Heenam Stanley

    2016-03-01

    Atopic dermatitis (AD) is a serious global epidemic associated with a modern lifestyle. Although aberrant interactions between gut microbes and the intestinal immune system have been implicated in this skin disease, the nature of the microbiome dysfunction underlying the disease remains unclear. The gut microbiome from 132 subjects, including 90 patients with AD, was analyzed by using 16S rRNA gene and metagenome sequence analyses. Reference genomes from the Human Microbiome Project and the KEGG Orthology database were used for metagenome analyses. Short-chain fatty acids in fecal samples were compared by using gas chromatographic-mass spectrometric analyses. We show that enrichment of a subspecies of the major gut species Faecalibacterium prausnitzii is strongly associated with AD. In addition, the AD microbiome was enriched in genes encoding the use of various nutrients that could be released from damaged gut epithelium, reflecting a bloom of auxotrophic bacteria. Fecal samples from patients with AD showed decreased levels of butyrate and propionate, which have anti-inflammatory effects. This is likely a consequence of an intraspecies compositional change in F prausnitzii that reduces the number of high butyrate and propionate producers, including those related to the strain A2-165, a lack of which has been implicated in patients with Crohn disease. The data suggest that feedback interactions between dysbiosis in F prausnitzii and dysregulation of gut epithelial inflammation might underlie the chronic progression of AD by resulting in impairment of the gut epithelial barrier, which ultimately leads to aberrant TH2-type immune responses to allergens in the skin. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  17. Mass Spectrometry-Based Metabolomic and Proteomic Strategies in Organic Acidemias

    PubMed Central

    Imperlini, Esther; Santorelli, Lucia; Orrù, Stefania; Scolamiero, Emanuela; Ruoppolo, Margherita

    2016-01-01

    Organic acidemias (OAs) are inherited metabolic disorders caused by deficiency of enzymatic activities in the catabolism of amino acids, carbohydrates, or lipids. These disorders result in the accumulation of mono-, di-, or tricarboxylic acids, generally referred to as organic acids. The OA outcomes can involve different organs and/or systems. Some OA disorders are easily managed if promptly diagnosed and treated, whereas, in others cases, such as propionate metabolism-related OAs (propionic acidemia, PA; methylmalonic acidemia, MMA), neither diet, vitamin therapy, nor liver transplantation appears to prevent multiorgan impairment. Here, we review the recent developments in dissecting molecular bases of OAs by using integration of mass spectrometry- (MS-) based metabolomic and proteomic strategies. MS-based techniques have facilitated the rapid and economical evaluation of a broad spectrum of metabolites in various body fluids, also collected in small samples, like dried blood spots. This approach has enabled the timely diagnosis of OAs, thereby facilitating early therapeutic intervention. Besides providing an overview of MS-based approaches most frequently used to study the molecular mechanisms underlying OA pathophysiology, we discuss the principal challenges of metabolomic and proteomic applications to OAs. PMID:27403441

  18. Induction of Fetal Hemoglobin by Propionic and Butyric Acid Derivatives: Correlations between Chemical Structure and Potency of Hb F Induction1

    PubMed Central

    Liakopoulou, Effie; Li, Qiliang; Stamatoyannopoulos, George

    2010-01-01

    Short-chain fatty acids (C2-C9) induce fetal hemoglobin synthesis in primary cell cultures, primates, and patients. We carried out experiments to test whether relationships exist between chemical structure and the Hb F-inducing potential of several short-chain fatty acid derivatives. BFUe cultures were performed in the presence of propionic and butyric congeners, covering the full spectrum of substitutions of these molecules, including polar and non-polar groups, esters, and double bonds. We found that the fetal hemoglobin inducibility is related to the chemical structure of the inducing compound. This structure–activity relation depends on the length of carbon chain, the nature of the substitutions, and the position of more potent substitutions on the carbon chain. It appears that substitutions enhancing the inducibility of these compounds are (with decreasing potency): methyl > phenyl > hydroxy ≫ amino groups. Placement of these substitutions at a position distal to the carboxyl group enhances γ-globin inducibility. Presence of the carboxyl group is prerequisite for γ-globin inducibility. PMID:12482403

  19. Influence of alkyl sulfates on waste activated sludge fermentation at ambient temperature.

    PubMed

    Jiang, Su; Chen, Yinguang; Zhou, Qi

    2007-09-05

    Alkyl sulfates (AS), such as sodium dodecyl sulfate (SDS), are widely used in household and industrial products, and can be found in some wastewater and waste activated sludge (WAS). The effect of SDS on the fermentation of WAS at ambient temperature was investigated in this paper. Experimental results showed that the concentrations of protein and carbohydrate in aqueous phase increased with the amount of SDS. The concentrations of both NH(4)(+)-N and PO(4)(3-)-P in fermentation liquor also increased in the presence of SDS. In addition, it was observed that the fermentative short-chain fatty acids (SCFAs) concentration was affected by SDS. With the increase of SDS dosage, the maximum SCFAs concentration increased, and the fermentation time before reaching the maximum SCFAs concentration also increased. Further investigation showed that the produced SCFAs consisted of acetic, propionic, n-butyric, iso-butyric, n-valeric and iso-valeric acids, and acetic, iso-valeric and propionic acids were the three main products. The influence of SDS on methanogenesis was also investigated, and the inhibitory effect of SDS on methanogens activity was observed.

  20. Nanocomposite of Half-Fin Anchovy Hydrolysates/Zinc Oxide Nanoparticles Exhibits Actual Non-Toxicity and Regulates Intestinal Microbiota, Short-Chain Fatty Acids Production and Oxidative Status in Mice

    PubMed Central

    Song, Ru; Yao, Jianbin; Shi, Qingqing; Wei, Rongbian

    2018-01-01

    The nanocomposite of half-fin anchovy hydrolysates (HAHp) and zinc oxide nanoparticles (ZnO NPs) (named as HAHp(3.0)/ZnO NPs) demonstrated increased antibacterial activity compared to either HAHp(3.0) or ZnO NPs as per our previous studies. Also, reactive oxygen species (ROS) formation was detected in Escherichia coli cells after treatment with HAHp(3.0)/ZnO NPs. The aim of the present study was to evaluate the acute toxicity of this nanocomposite and to investigate its effect on intestinal microbiota composition, short-chain fatty acids (SCFAs) production, and oxidative status in healthy mice. The limit test studies show that this nanoparticle is non-toxic at the doses tested. The administration of HAHp(3.0)/ZnO NPs, daily dose of 1.0 g/kg body weight for 14 days, increased the number of goblet cells in jejunum. High-throughput 16S ribosomal RNA gene sequencing of fecal samples revealed that HAHp(3.0)/ZnO NPs increased Firmicutes and reduced Bacteriodetes abundances in female mice. Furthermore, the microbiota for probiotic-type bacteria, including Lactobacillus and Bifidobacterium, and SCFAs-producing bacteria in the Clostridia class, e.g., Lachnospiraceae_unclassified and Lachnospiraceae_UCG-001, were enriched in the feces of female mice. Increases of SCFAs, especially statistically increased propionic and butyric acids, indicated the up-regulated anti-inflammatory activity of HAHp(3.0)/ZnO NPs. Additionally, some positive responses in liver, like markedly increased glutathione and decreased malonaldehyde contents, indicated the improved oxidative status. Therefore, our results suggest that HAHp(3.0)/ZnO NPs could have potential applications as a safe regulator of intestinal microbiota or also can be used as an antioxidant used in food products. PMID:29324644

  1. Effects of dietary supplementation of rumen-protected folic acid on rumen fermentation, degradability and excretion of urinary purine derivatives in growing steers.

    PubMed

    Wang, Cong; Liu, Qiang; Guo, Gang; Huo, WenJie; Ma, Le; Zhang, YanLi; Pei, CaiXia; Zhang, ShuanLin; Wang, Hao

    2016-12-01

    The present experiment was undertaken to determine the effects of dietary addition of rumen-protected folic acid (RPFA) on ruminal fermentation, nutrient degradability, enzyme activity and the relative quantity of ruminal cellulolytic bacteria in growing beef steers. Eight rumen-cannulated Jinnan beef steers averaging 2.5 years of age and 419 ± 1.9 kg body weight were used in a replicated 4 × 4 Latin square design. The four treatments comprised supplementation levels of 0 (Control), 70, 140 and 210 mg RPFA/kg dietary dry matter (DM). On DM basis, the ration consisted of 50% corn silage, 47% concentrate and 3% soybean oil. The DM intake (averaged 8.5 kg/d) was restricted to 95% of ad libitum intake. The intake of DM, crude protein (CP) and net energy for growth was not affected by treatments. In contrast, increasing RPFA supplementation increased average daily gain and the concentration of total volatile fatty acid and reduced ruminal pH linearly. Furthermore, increasing RPFA supplementation enhanced the acetate to propionate ratio and reduced the ruminal ammonia N content linearly. The ruminal effective degradability of neutral detergent fibre from corn silage and CP from concentrate improved linearly and was highest for the highest supplementation levels. The activities of cellobiase, xylanase, pectinase and α-amylase linearly increased, but carboxymethyl-cellulase and protease were not affected by the addition of RPFA. The relative quantities of Butyrivibrio fibrisolvens, Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes increased linearly. With increasing RPFA supplementation levels, the excretion of urinary purine derivatives was also increased linearly. The present results indicated that the supplementation of RPFA improved ruminal fermentation, nutrient degradability, activities of microbial enzymes and the relative quantity of the ruminal cellulolytic bacteria in a dose-dependent manner. According to the conditions of this experiment, the optimum supplementation level of RPFA was 140 mg/kg DM.

  2. Suitability of combination of calcium propionate and chitosan for preserving minimally processed banana quality.

    PubMed

    Mirshekari, Amin; Madani, Babak; Golding, John B

    2017-08-01

    The marketability of fresh-cut banana slices is limited by the rapid rate of fruit softening and browning. However, there is no scientific literature available about the role of postharvest calcium propionate and chitosan treatment on the quality attributes of fresh-cut banana. Therefore, the aim of the present study was to investigate these effects. The application of calcium propionate plus chitosan (CaP+Chit) retained higher firmness, higher ascorbic acid content, higher total antioxidant activity and higher total phenolic compounds, along with lower browning, lower polyphenol oxidase, lower peroxidase, lower polygalacturonase and lower pectin methyl esterase activities and microbial growth, compared to control banana slices after 5 days of cold storage. The results of the present study show that CaP+Chit could be used to slow the loss of quality at the same time as maintaining quality and inhibiting microbial loads. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Effect of carbon source type on intracellular stored polymers during endogenous denitritation (ED) treating landfill leachate.

    PubMed

    Miao, Lei; Wang, Shuying; Li, Baikun; Cao, Tianhao; Zhang, Fangzhai; Wang, Zhong; Peng, Yongzhen

    2016-09-01

    Glycogen accumulating organisms (GAOs) capable of storing organic compounds as polyhydroxyalkanoate (PHA) have been used for endogenous denitritation (ED), but the effect of carbon sources type on nitrogen removal performance of GAOs treating landfill leachate is unclear. In this study, a successful ED system treating landfill leachate (COD/NH4(+)-N (C/N): 4) without external carbon source addition was applied. The mature leachate with C/N of 1 was used as the feeding base solution, with acetate, propionate, and glucose examined as the carbon sources, and their effects on yields and compositions of PHA produced by GAOs were determined and associated with nitrogen removal performance. In the case of sole carbon source, acetate was much easier to be stored than propionate and glucose, which led to a higher nitrogen removal efficiency. Glucose had the lowest amount of PHA storage and led to the lowest performance. In the case of composite carbon sources (two scenarios: acetate + propionate; acetate + propionate + glucose), GAOs stored sufficient PHA and exhibited similar nitrogen removal efficiencies. Moreover, type of carbon source influenced the compositions of PHA. The polyhydroxybutyrate (PHB) fraction in PHA was far more than polyhydroxyvalerate (PHV) in all tests. PHV was synthesized only when acetate existed in carbon source. The microbial diversity analysis revealed that Proteobacteria was the most abundant phylum. Among the 108 genera detected in this ED system, the genera responsible for denitritation were Thauera, Paracoccus, Ottowia and Comamonadaceae_unclassified, accounting for 46.21% of total bacteria. Especially, Paracoccus and Comamonadaceae_unclassified transformed the carbon source into PHA for denitritation, and carried out endogenous denitritation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. A theoretical comparison between two ruminal electron sinks

    PubMed Central

    Ungerfeld, Emilio M.

    2013-01-01

    Dihydrogen accumulation resulting from methanogenesis inhibition in the rumen is an energy loss and can inhibit fermentation. The objective of this analysis was to compare the energetic and nutritional consequences of incorporating H2 into reductive acetogenesis or additional propionate production beyond the acetate to propionate shift occurring along with methanogenesis inhibition. Stoichiometric consequences were calculated for a simulated fermentation example. Possible nutritional consequences are discussed. Incorporating H2 into reductive acetogenesis or additional propionate production resulted in equal heat of combustion output in volatile fatty acids (VFA). Incorporation of H2 into reductive acetogenesis could result in moderate decrease in ruminal pH, although whole-animal buffering mechanisms make pH response difficult to predict. Research would be needed to compare the microbial protein production output. There could be post-absorptive implications due to differences in VFA profile. Electron incorporation into reductive acetogenesis could favor energy partition toward milk, but increase risk of ketosis in high-producing dairy cows on ketogenic diets. Greater propionate production could favor milk protein production, but may be less desirable in animals whose intake is metabolically constrained, like feedlot steers. Because of the different nutritional implications, and because practical solutions to incorporate H2 into either pathway are not yet available, it is recommended to research both alternatives. PMID:24198813

  5. Feasibility study on the utilization of rubber latex effluent for producing bacterial biopolymers.

    PubMed

    Tang, S N; Fakhru'l-Razi, A; Hassan, M A; Karim, M I

    1999-01-01

    Rubber latex effluent is a polluting source that has a high biochemical oxygen demand (BOD). It is estimated that about 100 million liters of effluent are discharged daily from rubber processing factories. Utilization of this effluent such as the use of a coupled system not only can reduce the cost of treatment but also yield a fermentation feedstock for the production of bioplastic. This study initially was carried out to increase the production of organic acids by anaerobic treatment of rubber latex effluent. It was found that through anaerobic treatment the concentration of organic acids did not increase. Consequently, separation of organic acids from rubber latex effluent by anion exchange resin was examined as a preliminary study of recovering acetic and propionic acids. However, the suspended solids (SS) content in the raw effluent was rather high which partially blocked the ion-exchange columns. Lime was used to remove the SS in the rubber latex effluent. After the lime precipitation process, organic acids were found to adsorb strongly onto the anion exchange resin. Less adsorption of organic acids onto the resin was observed before the lime precipitation. This was probably due to more sites being occupied by colloidal particles on the resin thus inhibiting the adsorption of organic acids. The initial concentration of organic acids in the raw effluent was 3.9 g/L. After ion exchange, the concentration of the organic acids increased to 27 g/L, which could be utilized for production of polyhydroxyalkanoates (PHA). For PHA accumulation stage, concentrated rubber latex effluent obtained from ion exchange resins and synthetic acetic acid were used as the carbon source. Quantitative analyses from fed batch culture via HPLC showed that the accumulation of PHA in Alcaligenes eutrophus was maximum with a concentration of 1.182 g/L when cultivated on synthetic acetic acid, corresponding to a yield of 87% based on its cell dry weight. The dry cell weight increased from 0.71 to 1.67 g/L. On the other hand, using concentrated rubber latex effluent containing acetic and propionic acids resulted in reduced PHA content by dry weight (14%) but the dry cell weight increased from 0.49 to 1.30 g/L. The results clearly indicated that the cells grow well in rubber latex effluent but no PHA was accumulated. This could be due to the high concentration of propionic acid in culture broth or other factors such as heavy metals. Thus further work is required before rubber latex effluent can be utilized as a substrate for PHA production industrially.

  6. Pentadecanoic and Heptadecanoic Acids: Multifaceted Odd-Chain Fatty Acids12

    PubMed Central

    Pfeuffer, Maria; Jaudszus, Anke

    2016-01-01

    The odd-chain fatty acids (OCFAs) pentadecanoic acid (15:0) and heptadecanoic acid (17:0), which account for only a small proportion of total saturated fatty acids in milk fat and ruminant meat, are accepted biomarkers of dairy fat intake. However, they can also be synthesized endogenously, for example, from gut-derived propionic acid (3:0). A number of studies have shown an inverse association between OCFA concentrations in human plasma phospholipids or RBCs and risk of type 2 diabetes and cardiovascular disease. We propose a possible involvement in metabolic regulation from the assumption that there is a link between 15:0 and 17:0 and the metabolism of other short-chain, medium-chain, and longer-chain OCFAs. The OCFAs 15:0 and 17:0 can be elongated to very-long-chain FAs (VLCFAs) such as tricosanoic acid (23:0) and pentacosanoic acid (25:0) in glycosphingolipids, particularly found in brain tissue, or can be derived from these VLCFAs. Their chains can be shortened, yielding propionyl-coenzyme A (CoA). Propionyl-CoA, by succinyl-CoA, can replenish the citric acid cycle (CAC) with anaplerotic intermediates and, thus, improve mitochondrial energy metabolism. Mitochondrial function is compromised in a number of disorders and may be impaired with increasing age. Optimizing anaplerotic intermediate availability for the CAC may help to cope with demands in times of increased metabolic stress and with aging. OCFAs may serve as substrates for synthesis of both odd-numbered VLCFAs and propionyl-CoA or store away excess propionic acid. PMID:27422507

  7. Effect of carbon sources on the aggregation of photo fermentative bacteria induced by L-cysteine for enhancing hydrogen production.

    PubMed

    Xie, Guo-Jun; Liu, Bing-Feng; Ding, Jie; Wang, Qilin; Ma, Chao; Zhou, Xu; Ren, Nan-Qi

    2016-12-01

    Poor flocculation of photo fermentative bacteria resulting in continuous biomass washout from photobioreactor is a critical challenge to achieve rapid and stable hydrogen production. In this work, the aggregation of Rhodopseudomonas faecalis RLD-53 was successfully developed in a photobioreactor and the effects of different carbon sources on hydrogen production and aggregation ability were investigated. Extracellular polymeric substances (EPS) production by R. faecalis RLD-53 cultivated using different carbon sources were stimulated by addition of L-cysteine. The absolute ζ potentials of R. faecalis RLD-53 were considerably decreased with addition of L-cysteine, and aggregation barriers based on DLVO dropped to 15-43 % of that in control groups. Thus, R. faecalis RLD-53 flocculated effectively, and aggregation abilities of strain RLD-53 cultivated with acetate, propionate, lactate and malate reached 29.35, 32.34, 26.07 and 24.86 %, respectively. In the continuous test, hydrogen-producing activity was also promoted and reached 2.45 mol H 2 /mol lactate, 3.87 mol H 2 /mol propionate and 5.10 mol H 2 /mol malate, respectively. Therefore, the aggregation of R. faecalis RLD-53 induced by L-cysteine is independent on the substrate types, which ensures the wide application of this technology to enhance hydrogen recovery from wastewater dominated by different organic substrates.

  8. Influence of chain ordering on the selectivity of dipalmitoylphosphatidylcholine bilayer membranes for permeant size and shape.

    PubMed Central

    Xiang, T X; Anderson, B D

    1998-01-01

    The effects of lipid chain packing and permeant size and shape on permeability across lipid bilayers have been investigated in gel and liquid crystalline dipalmitoylphosphatidylcholine (DPPC) bilayers by a combined NMR line-broadening/dynamic light scattering method using seven short-chain monocarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, and trimethylacetic acid) as permeants. The experimental permeability coefficients are compared with the predictions of a bulk solubility diffusion model in which the bilayer membrane is represented as a slab of bulk hexadecane. Deviations of the observed permeability coefficients (Pm) from the values predicted from solubility diffusion theory (Po) lead to the determination of a correction factor, the permeability decrement f (= Pm/Po), to account for the effects of chain ordering. The natural logarithm of f has been found to correlate linearly with the inverse of the bilayer free surface area with slopes of 25 +/- 2, 36 +/- 3, 45 +/- 8, 32 +/- 12, 33 +/- 4, 49 +/- 12, and 75 +/- 6 A2 for formic acid, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, and trimethylacetic acid, respectively. The slope, which measures the sensitivity of the permeability coefficient of a given permeant to bilayer chain packing, exhibits an excellent linear correlation (r = 0.94) with the minimum cross-sectional area of the permeant and a poor correlation (r = 0.59) with molecular volume, suggesting that in the bilayer interior the permeants prefer to move with their long principal axis along the bilayer normal. Based on these studies, a permeability model combining the effects of bilayer chain packing and permeant size and shape on permeability across lipid membranes is developed. PMID:9826590

  9. Preservation of hay with propionic acid

    USDA-ARS?s Scientific Manuscript database

    Most hay producers are quite familiar with the problems associated with baling moist hays. Normally, these problems include spontaneous heating, increased evidence of mold, losses of dry matter (DM) during storage, poorer nutritive value, and (in extreme cases) spontaneous combustion. Numerous fact...

  10. Propionic acid preservatives for hay

    USDA-ARS?s Scientific Manuscript database

    Hay producers working in humid environments are well-acquainted with the consequences of baling moist hays, which include heating, molding, losses of dry matter and nutritive value, and the possibility of spontaneous combustion. Traditionally, the effect of heat damage within forages has focused on ...

  11. Reactive Distillation for Esterification of Bio-based Organic Acids

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

    Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.

    2008-09-23

    The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scalemore » has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential Equilibrium and Dynamics) method.« less

  12. Preparation of nickel aluminum-manganese spinel oxides Ni{sub x}Al{sub 1{minus}x}Mn{sub 2}O{sub 4} for oxygen electrocatalysis in alkaline medium: Comparison of properties stemming from different preparation methods

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

    Ponce, J.; Rios, E.; Gautier, J.L.

    Two different procedures were used to prepare spinel-type Ni{sub x}Al{sub 1{minus}x}Mn{sub 2}O{sub 4} (0 {le} x {le} 1) compounds to study the effects of solid state properties of mixed oxides on their electrocatalytic properties. The oxalic route, coprecipitation of metal oxalates dissolved in propanol or ethanol, and the propionic route, hydrolysis of metal carboxylates in propionic acid, have been used. In both routes, thermal decomposition produces the corresponding oxides. X-ray diffraction patterns showed that the oxides crystallize in a cubic spinel phase with a unit cell parameter a that increases as aluminum is replaced by nickel. At low x values,more » compounds prepared by the propionic route showed a larger variation for parameter a than compounds prepared by the oxalic route, probably due to oxygen stoichiometric deficiency. This effect was estimated from the tetrahedral force constant (k{sub 1}) values, which showed a fast decrease as x varied from 0 to 1. Electrical conductivity, conduction activation energy, hole mobility, and pHz of oxides prepared by the propionic route were also higher than those from oxides prepared by the oxalic route. Crystallinity grade and particle size were nearly 50% higher in propionic-route samples than in oxalic-route samples. The apparent and real electrocatalytic activities of both types of oxides were compared for O{sub 2} evolution. 42 refs., 6 figs., 4 tabs.« less

  13. Effect of sodium lauryl sulfate-fumaric Acid coupled addition on the in vitro rumen fermentation with special regard to methanogenesis.

    PubMed

    Abdl-Rahman, M A; Sawiress, F A R; Abd El-Aty, A M

    2010-01-01

    The aim of the current study was to evaluate the effect of sodium lauryl sulfate-fumaric acid coupled addition on in vitro methangenesis and rumen fermentation. Evaluation was carried out using in vitro gas production technique. Ruminal contents were collected from five steers immediately after slaughtering and used for preparation of inoculums of mixed rumen microorganisms. Rumen fluid was then mixed with the basal diet of steers and used to generate four treatments, negative control (no additives), sodium lauryl sulfate (SLS) treated, fumaric acid treated, and SLS-fumaric acid coupled addition treated. The results revealed that, relative to control, efficiency in reduction of methanogenesis was as follows: coupled addition > SLS-addition > fumaric acid addition. Both SLS-addition and SLS-fumaric acid coupled addition demonstrated a decremental effect on ammonia nitrogen (NH(3)-N), total short chain volatile fatty acids (SCVFAs) concentrations and the amount of substrate degraded, and an increment effect on microbial mass and microbial yield (Y(ATP)). Nevertheless, fumaric acid did not alter any of the previously mentioned parameters but induced a decremental effect on NH(3)-N. Furthermore, both fumaric acid and SLS-fumaric acid coupled addition increased propionate at the expense of acetate and butyrate, while, defaunation increased acetate at the expense of propionate and butyrate. The pH value was decreased by all treatments relative to control, while, cellulase activity did not differ by different treatments. The current study can be promising strategies for suppressing ruminal methane emissions and improving ruminants feed efficiency.

  14. Effect of Sodium Lauryl Sulfate-Fumaric Acid Coupled Addition on the In Vitro Rumen Fermentation with Special Regard to Methanogenesis

    PubMed Central

    Abdl-Rahman, M. A.; Sawiress, F. A. R.; Abd El-Aty, A. M.

    2010-01-01

    The aim of the current study was to evaluate the effect of sodium lauryl sulfate-fumaric acid coupled addition on in vitro methangenesis and rumen fermentation. Evaluation was carried out using in vitro gas production technique. Ruminal contents were collected from five steers immediately after slaughtering and used for preparation of inoculums of mixed rumen microorganisms. Rumen fluid was then mixed with the basal diet of steers and used to generate four treatments, negative control (no additives), sodium lauryl sulfate (SLS) treated, fumaric acid treated, and SLS-fumaric acid coupled addition treated. The results revealed that, relative to control, efficiency in reduction of methanogenesis was as follows: coupled addition > SLS-addition > fumaric acid addition. Both SLS-addition and SLS-fumaric acid coupled addition demonstrated a decremental effect on ammonia nitrogen (NH3–N), total short chain volatile fatty acids (SCVFAs) concentrations and the amount of substrate degraded, and an increment effect on microbial mass and microbial yield (YATP). Nevertheless, fumaric acid did not alter any of the previously mentioned parameters but induced a decremental effect on NH3–N. Furthermore, both fumaric acid and SLS-fumaric acid coupled addition increased propionate at the expense of acetate and butyrate, while, defaunation increased acetate at the expense of propionate and butyrate. The pH value was decreased by all treatments relative to control, while, cellulase activity did not differ by different treatments. The current study can be promising strategies for suppressing ruminal methane emissions and improving ruminants feed efficiency. PMID:20445794

  15. Amavadin and other vanadium complexes as remarkably efficient catalysts for one-pot conversion of ethane to propionic and acetic acids.

    PubMed

    Kirillova, Marina V; Kuznetsov, Maxim L; da Silva, José A L; Guedes da Silva, Maria Fátima C; Fraústo da Silva, João J R; Pombeiro, Armando J L

    2008-01-01

    Synthetic amavadin Ca[V{ON[CH(CH(3))COO](2)}(2)] and its models Ca[V{ON(CH(2)COO)(2)}(2)] and [VO{N(CH(2)CH(2)O)(3)}], in the presence of K(2)S(2)O(8) in trifluoroacetic acid (TFA), exhibit remarkable catalytic activity for the one-pot carboxylation of ethane to propionic and acetic acids with the former as the main product (overall yields up to 93 %, catalyst turnover numbers (TONs) up to 2.0 x 10(4)). The simpler V complexes [VO(CF(3)SO(3))(2)], [VO(acac)(2)] and VOSO(4) are less active. The effects of various factors, namely, C(2)H(6) and CO pressures, time, temperature, and amounts of catalyst, TFA and K(2)S(2)O(8), have been investigated, and this allowed optimisation of the process and control of selectivity. (13)C-labelling experiments indicated that the formation of acetic acid follows two pathways, the dominant one via oxidation of ethane with preservation of the C--C bond, and the other via rupture of this bond and carbonylation of the methyl group by CO; the C--C bond is retained in the formation of propionic acid upon carbonylation of ethane. The reactions proceed via both C- and O-centred radicals, as shown by experiments with radical traps. On the basis of detailed DFT calculations, plausible reaction mechanisms are discussed. The carboxylation of ethane in the presence of CO follows the sequential formation of C(2)H(5) (*), C(2)H(5)CO(*), C(2)H(5)COO(*) and C(2)H(5)COOH. The C(2)H(5)COO(*) radical is easily formed on reaction of C(2)H(5)CO(*) with a peroxo V catalyst via a V{eta(1)-OOC(O)C(2)H(5)} intermediate. In the absence of CO, carboxylation proceeds by reaction of C(2)H(5) (*) with TFA. For the oxidation of ethane to acetic acid, either with preservation or cleavage of the C-C bond, metal-assisted and purely organic pathways are also proposed and discussed.

  16. Response kinetics of tethered bacteria to stepwise changes in nutrient concentration.

    PubMed

    Chernova, Anna A; Armitage, Judith P; Packer, Helen L; Maini, Philip K

    2003-09-01

    We examined the changes in swimming behaviour of the bacterium Rhodobacter sphaeroides in response to stepwise changes in a nutrient (propionate), following the pre-stimulus motion, the initial response and the adaptation to the sustained concentration of the chemical. This was carried out by tethering motile cells by their flagella to glass slides and following the rotational behaviour of their cell bodies in response to the nutrient change. Computerised motion analysis was used to analyse the behaviour. Distributions of run and stop times were obtained from rotation data for tethered cells. Exponential and Weibull fits for these distributions, and variability in individual responses are discussed. In terms of parameters derived from the run and stop time distributions, we compare the responses to stepwise changes in the nutrient concentration and the long-term behaviour of 84 cells under 12 propionate concentration levels from 1 nM to 25 mM. We discuss traditional assumptions for the random walk approximation to bacterial swimming and compare them with the observed R. sphaeroides motile behaviour.

  17. Metabolic engineering of Clostridium autoethanogenum for selective alcohol production.

    PubMed

    Liew, Fungmin; Henstra, Anne M; Kӧpke, Michael; Winzer, Klaus; Simpson, Sean D; Minton, Nigel P

    2017-03-01

    Gas fermentation using acetogenic bacteria such as Clostridium autoethanogenum offers an attractive route for production of fuel ethanol from industrial waste gases. Acetate reduction to acetaldehyde and further to ethanol via an aldehyde: ferredoxin oxidoreductase (AOR) and alcohol dehydrogenase has been postulated alongside the classic pathway of ethanol formation via a bi-functional aldehyde/alcohol dehydrogenase (AdhE). Here we demonstrate that AOR is critical to ethanol formation in acetogens and inactivation of AdhE led to consistently enhanced autotrophic ethanol production (up to 180%). Using ClosTron and allelic exchange mutagenesis, which was demonstrated for the first time in an acetogen, we generated single mutants as well as double mutants for both aor and adhE isoforms to confirm the role of each gene. The aor1+2 double knockout strain lost the ability to convert exogenous acetate, propionate and butyrate into the corresponding alcohols, further highlighting the role of these enzymes in catalyzing the thermodynamically unfavourable reduction of carboxylic acids into alcohols. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. In vitro effects of hydrochloric acid and various concentrations of acetic, propionic, butyric, or valeric acids on bioelectric properties of equine gastric squamous mucosa.

    PubMed

    Andrews, Frank M; Buchanan, Benjamin R; Smith, Sionagh H; Elliott, Sarah B; Saxton, Arnold M

    2006-11-01

    To compare the effects of hydrochloric acid (HCl) and various concentrations of volatile fatty acids (VFAs) on tissue bioelectric properties of equine stomach nonglandular (NG) mucosa. Gastric tissues obtained from 48 adult horses. NG gastric mucosa was studied by use of Ussing chambers. Short-circuit current (Isc) and potential difference (PD) were measured and electrical resistance (R) and conductance calculated for tissues after addition of HCl and VFAs (5, 10, 20, and 40 mM) in normal Ringer's solution (NRS). Mucosa exposed to HCl in NRS (pH of 1.5 and, to a lesser extent, 4.0) had a significant decrease in Isc, PD, and R, whereas tissues exposed to acetic acid at a pH of < 4.0, propionic and butyric acids at a pH of

  19. Sustainable and efficient biohydrogen production via electrohydrogenesis.

    PubMed

    Cheng, Shaoan; Logan, Bruce E

    2007-11-20

    Hydrogen gas has tremendous potential as an environmentally acceptable energy carrier for vehicles, but most hydrogen is generated from nonrenewable fossil fuels such as natural gas. Here, we show that efficient and sustainable hydrogen production is possible from any type of biodegradable organic matter by electrohydrogenesis. In this process, protons and electrons released by exoelectrogenic bacteria in specially designed reactors (based on modifying microbial fuel cells) are catalyzed to form hydrogen gas through the addition of a small voltage to the circuit. By improving the materials and reactor architecture, hydrogen gas was produced at yields of 2.01-3.95 mol/mol (50-99% of the theoretical maximum) at applied voltages of 0.2 to 0.8 V using acetic acid, a typical dead-end product of glucose or cellulose fermentation. At an applied voltage of 0.6 V, the overall energy efficiency of the process was 288% based solely on electricity applied, and 82% when the heat of combustion of acetic acid was included in the energy balance, at a gas production rate of 1.1 m(3) of H(2) per cubic meter of reactor per day. Direct high-yield hydrogen gas production was further demonstrated by using glucose, several volatile acids (acetic, butyric, lactic, propionic, and valeric), and cellulose at maximum stoichiometric yields of 54-91% and overall energy efficiencies of 64-82%. This electrohydrogenic process thus provides a highly efficient route for producing hydrogen gas from renewable and carbon-neutral biomass resources.

  20. Effects of organic loading rate on hydrogen and volatile fatty acid production and microbial community during acidogenic hydrogenesis in a continuous stirred tank reactor using molasses wastewater.

    PubMed

    Yun, J; Cho, K-S

    2016-12-01

    Microbial community associated with hydrogen production and volatile fatty acids (VFAs) accumulation was characterized in acidogenic hydrogenesis using molasses wastewater as a feedstock. Hydrogen and VFAs production were measured under an organic loading rate (OLR) from 19 to 35 g-COD l -1  day -1 . The active microbial community was analysed using RNA-based massively parallel sequencing technique, and their correlation patterns were analysed using networking analysis. The continuous stirred tank reactor achieved stable hydrogen production at different OLR conditions, and the maximum hydrogen production rate (HPR) was 1·02 L-H 2  l -1  day -1 at 31·0 g-COD l -1  day -1 . Butyrate (50%) and acetate (38%) positively increased with increase in OLR. Total VFA production stayed around 7135 mg l -1 during the operation period. Although Clostridiales and Lactobacillales were relatively abundant, the HPR was positively associated with Pseudomonadaceae and Micrococcineae. Total VFA and acetate, butyrate and propionate concentrations were positively correlated with lactic acid bacteria (LAB) such as Bacillales, Sporolactobacillus and Lactobacillus. The close relationship between Pseudomonadaceae and Micrococcineae, and LAB play important roles for stable hydrogen and VFA production from molasses wastewater. Microbial information on hydrogen and VFA production can be useful to design and operate for acidogenic hydrogenesis using high strength molasses wastewater. © 2016 The Society for Applied Microbiology.

  1. Selective fermentation of carbohydrate and protein fractions of Scenedesmus, and biohydrogenation of its lipid fraction for enhanced recovery of saturated fatty acids.

    PubMed

    Lai, YenJung Sean; Parameswaran, Prathap; Li, Ang; Aguinaga, Alyssa; Rittmann, Bruce E

    2016-02-01

    Biofuels derived from microalgae have promise as carbon-neutral replacements for petroleum. However, difficulty extracting microalgae-derived lipids and the co-extraction of non-lipid components add major costs that detract from the benefits of microalgae-based biofuel. Selective fermentation could alleviate these problems by managing microbial degradation so that carbohydrates and proteins are hydrolyzed and fermented, but lipids remain intact. We evaluated selective fermentation of Scenedesmus biomass in batch experiments buffered at pH 5.5, 7, or 9. Carbohydrates were fermented up to 45% within the first 6 days, protein fermentation followed after about 20 days, and lipids (measured as fatty acid methyl esters, FAME) were conserved. Fermentation of the non-lipid components generated volatile fatty acids, with acetate, butyrate, and propionate being the dominant products. Selective fermentation of Scenedesmus biomass increased the amount of extractable FAME and the ratio of FAME to crude lipids. It also led to biohydrogenation of unsaturated FAME to more desirable saturated FAME (especially to C16:0 and C18:0), and the degree of saturation was inversely related to the accumulation of hydrogen gas after fermentation. Moreover, the microbial communities after selective fermentation were enriched in bacteria from families known to perform biohydrogenation, i.e., Porphyromonadaceae and Ruminococcaceae. Thus, this study provides proof-of-concept that selective fermentation can improve the quantity and quality of lipids that can be extracted from Scenedesmus. © 2015 Wiley Periodicals, Inc.

  2. Characterization of a bioflocculant produced by Citrobacter sp. TKF04 from acetic and propionic acids.

    PubMed

    Fujita, M; Ike, M; Tachibana, S; Kitada, G; Kim, S M; Inoue, Z

    2000-01-01

    A bacterial strain, TKF04, capable of producing a bioflocculant from acetic and/or propionic acids was isolated from a biofilm formed in inside a kitchen drain. It was identified as a Citrobacter based on its morphological and physiological characteristics and the partial sequences of its 16S rRNA. TKF04 produced the bioflocculant during the logarithmic phase of growth, and the optimum temperature and pH for the bioflocculant production were 30 degrees C and 7.2-10.0, respectively. It could utilize some organic acids and sugars for its growth as the sole carbon sources when yeast extract was supplemented; however, only acetate and propionate were found to be good substrates for the bioflocculant production. The crude bioflocculant could be recovered from the supernatant of the culture broth by ethanol precipitation and dialysis against deionized water. It was found to be effective for flocculation of a kaolin suspension, when added at a final concentration of 1-10 mg/l, over a wide range of pHs (2-8) and temperatures (approximately 3-95 degrees C), while the co-presence of cations (Na+, K+, Ca2+, Mg2+, Fe2+, Al3+ or Fe3+) did not enhance the flocculating activity. It could efficiently flocculate a variety of inorganic and organic suspended particles, including kaolin, diatomite, bentonite, activated carbon, soil and activated sludge. It contained glucosamine as the major component, and the molecular weight was estimated to be between 232 and 440 kDa by gel filtration. The observation that the flocculating activity was completely lost following chitinase treatment and its analysis with a Fourier transform infrared spectrometer suggested that the bioflocculant is a biopolymer structurally-similar to chitin or chitosan.

  3. Geochemical Data from Produced Water Contamination Investigations: Osage-Skiatook Petroleum Environmental Research (OSPER) Sites, Osage County, Oklahoma

    DTIC Science & Technology

    2007-01-01

    density polyethylene bottles prerinsed with deionized water for anions, and prerinsed with 5% nitric acid (HNO3) then deionized water for metals and...silica. The aliquots for metal and silica were acidified to pH ~1 with ultrex-grade nitric acid (HNO3). Sample aliquots for dissolved organic carbon (DOC...Br, NO3, PO4, SO4, and organic carboxylic acid anions (acetate, butyrate, formate, malonate, oxalate , propionate, and succinate) were determined by

  4. A method for measuring low-weight carboxylic acids from biosolid compost.

    PubMed

    Himanen, Marina; Latva-Kala, Kyösti; Itävaara, Merja; Hänninen, Kari

    2006-01-01

    Concentration of low-weight carboxylic acids (LWCA) is one of the important parameters that should be taken into consideration when compost is applied as soil improver for plant cultivation, because high amounts of LWCA can be toxic to plants. The present work describes a method for analysis of LWCA in compost as a useful tool for monitoring compost quality and safety. The method was tested on compost samples of two different ages: 3 (immature) and 6 (mature) months old. Acids from compost samples were extracted at high pH, filtered, and freeze-dried. The dried sodium salts were derivatized with a sulfuric acid-methanol mixture and concentrations of 11 low-weight fatty acids (C1-C10) were analyzed using headspace gas chromatography. The material was analyzed with two analytical techniques: the external calibration method (tested on 11 LWCA) and the standard addition method (tested only on formic, acetic, propionic, butyric, and iso-butyric acids). The two techniques were compared for efficiency of acids quantification. The method allowed good separation and quantification of a wide range of individual acids with high sensitivity at low concentrations. Detection limit for propionic, butyric, caproic, caprylic, and capric acids was 1 mg kg(-1) compost; for formic, acetic, valeric, enanthoic and pelargonic acids it was 5 mg kg(-1) compost; and for iso-butyric acid it was 10 mg kg(-1) compost. Recovery rates of LWCA were higher in 3-mo-old compost (57-99%) than in 6-mo-old compost (29-45%). In comparison with the external calibration technique the standard addition technique proved to be three to four times more precise for older compost and two times for younger compost. Disadvantages of the standard addition technique are that it is more time demanding and laborious.

  5. 21 CFR 184.1081 - Propionic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... manufacturing practice conditions of use: (1) The ingredient is used as an antimicrobial agent as defined in... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific...

  6. 21 CFR 184.1081 - Propionic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... manufacturing practice conditions of use: (1) The ingredient is used as an antimicrobial agent as defined in... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific...

  7. Effects of encapsulated Lactobacillus acidophilus along with pasteurized longan juice on the colon microbiota residing in a dynamic simulator of the human intestinal microbial ecosystem.

    PubMed

    Chaikham, Pittaya; Apichartsrangkoon, Arunee

    2014-01-01

    The effect of encapsulated Lactobacillus acidophilus LA5 along with pasteurized longan juice on the colon microbiota was investigated by applying a dynamic model of the human gastrointestinal tract. Encapsulated L. acidophilus LA5 in pasteurized longan juice or sole encapsulated L. acidophilus LA5 exhibited the efficiency of colonizing the colon and enabling the growth of colon lactobacilli as well as beneficial bifidobacteria but inhibited the growth of fecal coliforms and clostridia. Moreover, these treatments gave rise to a significant increase of lactic acid and short-chain fatty acids such as acetate, propionate, and butyrate. Although acetate displayed the highest quantity, it was likely that after incorporating encapsulated L. acidophilus LA5 plus pasteurized longan juice, quantity of butyrate exceed propionate, and acetate in comparison with their controls. Denaturant gradient gel electrophoresis patterns confirmed that various treatments affected the alteration of microbial community within the simulator of the human intestinal microbial ecosystem.

  8. Invited review: Essential oils as modifiers of rumen microbial fermentation.

    PubMed

    Calsamiglia, S; Busquet, M; Cardozo, P W; Castillejos, L; Ferret, A

    2007-06-01

    Microorganisms in the rumen degrade nutrients to produce volatile fatty acids and synthesize microbial protein as an energy and protein supply for the ruminant, respectively. However, this fermentation process has energy (losses of methane) and protein (losses of ammonia N) inefficiencies that may limit production performance and contribute to the release of pollutants to the environment. Antibiotic ionophores have been very successful in reducing these energy and protein losses in the rumen, but the use of antibiotics in animal feeds is facing reduced social acceptance, and their use has been banned in the European Union since January 2006. For this reason, scientists have become interested in evaluating other alternatives to control specific microbial populations to modulate rumen fermentation. Essential oils can interact with microbial cell membranes and inhibit the growth of some gram-positive and gram-negative bacteria. As a result of such inhibition, the addition of some plant extracts to the rumen results in an inhibition of deamination and methanogenesis, resulting in lower ammonia N, methane, and acetate, and in higher propionate and butyrate concentrations. Results have indicated that garlic oil, cinnamaldehyde (the main active component of cinnamon oil), eugenol (the main active component of the clove bud), capsaicin (the active component of hot peppers), and anise oil, among others, may increase propionate production, reduce acetate or methane production, and modify proteolysis, peptidolysis, or deamination in the rumen. However, the effects of some of these essential oils are pH and diet dependent, and their use may be beneficial only under specific conditions and production systems. For example, capsaicin appears to have small effects in high-forage diets, whereas the changes observed in high-concentrate diets (increases in dry matter intake and total VFA, and reduction in the acetateto-propionate ratio and ammonia N concentration) may be beneficial. Because plant extracts may act at different levels in the carbohydrate and protein degradation pathways, their careful selection and combination may provide a useful tool to manipulate rumen microbial fermentation effectively. However, additional research is required to establish the optimal dose in vivo in units of the active component, to consider the potential adaptation of microbial populations to their activities, to examine the presence of residues in the products (milk or meat), and to demonstrate improvements in animal performance.

  9. Fatty acid-oxidizing consortia along a nutrient gradient in the Florida Everglades.

    PubMed

    Chauhan, Ashvini; Ogram, Andrew

    2006-04-01

    The Florida Everglades is one of the largest freshwater marshes in North America and has been subject to eutrophication for decades. A gradient in P concentrations extends for several kilometers into the interior of the northern regions of the marsh, and the structure and function of soil microbial communities vary along the gradient. In this study, stable isotope probing was employed to investigate the fate of carbon from the fermentation products propionate and butyrate in soils from three sites along the nutrient gradient. For propionate microcosms, 16S rRNA gene clone libraries from eutrophic and transition sites were dominated by sequences related to previously described propionate oxidizers, such as Pelotomaculum spp. and Syntrophobacter spp. Significant representation was also observed for sequences related to Smithella propionica, which dismutates propionate to butyrate. Sequences of dominant phylotypes from oligotrophic samples did not cluster with known syntrophs but with sulfate-reducing prokaryotes (SRP) and Pelobacter spp. In butyrate microcosms, sequences clustering with Syntrophospora spp. and Syntrophomonas spp. dominated eutrophic microcosms, and sequences related to Pelospora dominated the transition microcosm. Sequences related to Pelospora spp. and SRP dominated clone libraries from oligotrophic microcosms. Sequences from diverse bacterial phyla and primary fermenters were also present in most libraries. Archaeal sequences from eutrophic microcosms included sequences characteristic of Methanomicrobiaceae, Methanospirillaceae, and Methanosaetaceae. Oligotrophic microcosms were dominated by acetotrophs, including sequences related to Methanosarcina, suggesting accumulation of acetate.

  10. Protein and metabolic engineering for the production of organic acids.

    PubMed

    Liu, Jingjing; Li, Jianghua; Shin, Hyun-Dong; Liu, Long; Du, Guocheng; Chen, Jian

    2017-09-01

    Organic acids are natural metabolites of living organisms. They have been widely applied in the food, pharmaceutical, and bio-based materials industries. In recent years, biotechnological routes to organic acids production from renewable raw materials have been regarded as very promising approaches. In this review, we provide an overview of current developments in the production of organic acids using protein and metabolic engineering strategies. The organic acids include propionic acid, pyruvate, itaconic acid, succinic acid, fumaric acid, malic acid and citric acid. We also expect that rapid developments in the fields of systems biology and synthetic biology will accelerate protein and metabolic engineering for microbial organic acid production in the future. Copyright © 2017. Published by Elsevier Ltd.

  11. Development and Validation of an in vitro Experimental GastroIntestinal Dialysis Model with Colon Phase to Study the Availability and Colonic Metabolisation of Polyphenolic Compounds.

    PubMed

    Breynaert, Annelies; Bosscher, Douwina; Kahnt, Ariane; Claeys, Magda; Cos, Paul; Pieters, Luc; Hermans, Nina

    2015-08-01

    The biological effects of polyphenols depend on their mechanism of action in the body. This is affected by bioconversion by colon microbiota and absorption of colonic metabolites. We developed and validated an in vitro continuous flow dialysis model with colon phase (GastroIntestinal dialysis model with colon phase) to study the gastrointestinal metabolism and absorption of phenolic food constituents. Chlorogenic acid was used as model compound. The physiological conditions during gastrointestinal digestion were mimicked. A continuous flow dialysis system simulated the one-way absorption by passive diffusion from lumen to mucosa. The colon phase was developed using pooled faecal suspensions. Several methodological aspects including implementation of an anaerobic environment, adapted Wilkins Chalgren broth medium, 1.10(8) CFU/mL bacteria suspension as inoculum, pH adaptation to 5.8 and implementation of the dialysis system were conducted. Validation of the GastroIntestinal dialysis model with colon phase system showed a good recovery and precision (CV < 16 %). Availability of chlorogenic acid in the small intestinal phase (37 ± 3 %) of the GastroIntestinal dialysis model with colon phase is comparable with in vivo studies on ileostomy patients. In the colon phase, the human faecal microbiota deconjugated chlorogenic acid to caffeic acid, 3,4-dihydroxyphenyl propionic acid, 4-hydroxybenzoic acid, 3- or 4-hydroxyphenyl acetic acid, 2-methoxy-4-methylphenol and 3-phenylpropionic acid. The GastroIntestinal dialysis model with colon phase is a new, reliable gastrointestinal simulation system. It permits a fast and easy way to predict the availability of complex secondary metabolites, and to detect metabolites in an early stage after digestion. Isolation and identification of these metabolites may be used as references for in vivo bioavailability experiments and for investigating their bioactivity in in vitro experiments. Georg Thieme Verlag KG Stuttgart · New York.

  12. Steroid catechol degradation: disecoandrostane intermediates accumulated by Pseudomonas transposon mutant strains.

    PubMed

    Leppik, R A

    1989-07-01

    Eleven transposon mutant strains affected in bile acid catabolism were each found to form yellow, muconic-like intermediates from bile acids. To characterize these unstable intermediates, media from the growth of one of these mutants with deoxycholic acid was treated with ammonia, then the crude product was methylated with diazomethane. Four compounds were subsequently isolated; spectral evidence suggested that they were methyl 12 alpha-hydroxy-3-oxo-23,24-dinorchola-1,4-dien-22-oate, methyl 4-aza-12 beta-hydroxy-9(10)-secoandrosta-1,3,5-triene-9,17-dione-3-carboxyl ate, 4-aza-9 alpha, 12 beta-dihydroxy-9(10)-secoandrosta-1,3,5-trien-17-one-3- methyl carboxylate and 4 alpha-[3'-propionic acid]-5-amino-7 beta-hydroxy-7 alpha beta-methyl- 3a alpha, 4,7,7a-tetrahydro-1-indanone-delta-lactam. It is proposed that the mutants are blocked in the utilization of such muconic-like compounds as the 3,12 beta-dihydroxy-5,9,17-trioxo-4(5),9(10)- disecoandrostal (10),2-dien-4-oic acid formed from deoxycholic acid. A further mutant was examined, which converted deoxycholic acid to 12 alpha-hydroxyandrosta-1,4-dien-3,17-dione, but accumulated yellow products from steroids which lacked a 12 alpha-hydroxy function, such as chenodeoxycholic acid. The products from the latter acid were treated as above; spectral evidence suggested that the two compounds isolated were methyl 4-aza-7-hydroxy-9(10)-secoandrosta-1,3,5- triene-9,17-dione-3-carboxylate and 4 alpha-[1'alpha-hydroxy-3'-propionic acid]-5-amino-7a beta-methyl-3a alpha,4,7,7a-tetrahydro-1-indanone-delta-lactam.

  13. Injection port derivatization following ion-pair hollow fiber-protected liquid-phase microextraction for determining acidic herbicides by gas chromatography/mass spectrometry.

    PubMed

    Wu, Jingming; Lee, Hian Kee

    2006-10-15

    Injection port derivatization following ion-pair hollow fiber-protected liquid-phase microextraction (LPME) for the trace determination of acidic herbicides (2,4-dichlorobenzoic acid, 2,4-dichlorophenoxyacetic acid, 2-(2,4-dichlorophenoxy)propionic acid, 3,5-dichlorobenzoic acid, 2-(2,4,5-trichlorophenoxy)propionic acid) in aqueous samples by gas chromatography/mass spectrometry (GC/MS) was developed. Prior to GC injection port derivatization, acidic herbicides were converted into their ion-pair complexes with tetrabutylammonium chloride in aqueous samples and then extracted by 1-octanol impregnated in the hollow fiber. Upon injection, ion pairs of acidic herbicides were quantitatively derivatized to their butyl esters in the GC injection port. Thus, several parameters related to the derivatization process (i.e., injection temperature, purge-off time) were evaluated, and main parameters affecting the hollow fiber-protected LPME procedure such as extraction organic solvent, ion-pair reagent type, pH of aqueous medium, concentration of ion-pair reagent, sodium chloride concentration added to the aqueous medium, stirring speed, and extraction time profile, optimized. At the selected extraction and derivatization conditions, no matrix effects were observed. This method proved good repeatability (RSDs <12.3%, n = 6) and good linearity (r2 > or = 0.9939) for spiked deionized water samples for five analytes. The limits of detection were in the range of 0.51-13.7 ng x L(-1) (S/N =3) under GC/MS selected ion monitoring mode. The results demonstrated that injection port derivatization following ion-pair hollow fiber-protected LPME was a simple, rapid, and accurate method for the determination of trace acidic herbicides from aqueous samples. In addition, this method proved to be environmentally friendly since it completely avoided open derivatization with potentially hazardous reagents.

  14. Prolonged restraint stressor exposure in outbred CD-1 mice impacts microbiota, colonic inflammation, and short chain fatty acids.

    PubMed

    Maltz, Ross M; Keirsey, Jeremy; Kim, Sandra C; Mackos, Amy R; Gharaibeh, Raad Z; Moore, Cathy C; Xu, Jinyu; Bakthavatchalu, Vasudevan; Somogyi, Arpad; Bailey, Michael T

    2018-01-01

    Stressor-exposure has been shown to exacerbate inflammation and change the composition of the gastrointestinal microbiota; however stressor-induced effects on microbiota-derived metabolites and their receptors are unknown. Thus, bacterial-produced short chain fatty acids (SCFAs), as well as microbial community composition, were assessed in the colons of mice exposed to stress during infection with Citrobacter rodentium. Mice were exposed to overnight restraint on 7 consecutive nights, or left undisturbed as a control. After the first exposure of restraint, mice were orally challenged with C. rodentium or with vehicle. Microbial community composition was assessed using 16S rRNA gene sequencing and SCFA levels measured using gas chromatography-mass spectrometry (GC-MS). Pathogen levels and colonic inflammation were also assessed 6 days post-infection. Results demonstrated that the microbial community structure and SCFA production were significantly affected by both stressor exposure and C. rodentium-infection. Exposure to prolonged restraint in the absence of infection significantly reduced SCFAs (acetic acid, butyric acid, and propionic acid). Multiple bacterial taxa were affected by stressor exposure, with the relative abundance of Lactobacillus being significantly reduced and directly correlated with propionic acid. Lactobacillus abundances were inversely correlated with colonic inflammation, supporting the contention that Lactobacillus helps to regulate mucosal inflammatory responses. Our data indicates that restraint stressor can have significant effects on pathogen-induced colonic inflammation and suggest that stressor-induced changes in the microbiota, microbial-produced SCFAs and their receptors may be involved.

  15. Substitution of common concentrates with by-products modulated ruminal fermentation, nutrient degradation, and microbial community composition in vitro.

    PubMed

    Ertl, P; Knaus, W; Metzler-Zebeli, B U; Klevenhusen, F; Khiaosa-Ard, R; Zebeli, Q

    2015-07-01

    A rumen simulation technique was used to evaluate the effects of the complete substitution of a common concentrate mixture (CON) with a mixture consisting solely of by-products from the food industry (BP) at 2 different forage-to-concentrate ratios on ruminal fermentation profile, nutrient degradation, and abundance of rumen microbiota. The experiment was a 2×2 factorial arrangement with 2 concentrate types (CON and BP) and 2 concentrate levels (25 and 50% of diet dry matter). The experiment consisted of 2 experimental runs with 12 fermentation vessels each (n=6 per treatment). Each run lasted for 10d, with data collection on the last 5d. The BP diets had lower starch, but higher neutral detergent fiber (NDF) and fat contents compared with CON. Degradation of crude protein was decreased, but NDF and nonfiber carbohydrate degradation were higher for the BP diets. At the 50% concentrate level, organic matter degradation tended to be lower for BP and CH4 formation per unit of NDF degraded was also lower for BP. The BP mixture led to a higher concentration of propionate and a lower acetate-to-propionate ratio, whereas concentrations of butyrate and caproate decreased. Concentrate type did not affect microbial community composition, except that the abundance of bacteria of the genus Prevotella was higher for BP. Increasing the concentrate level resulted in higher degradation of organic matter and crude protein. At the higher concentrate level, total short-chain fatty acid formation increased and concentrations of isobutyrate and valerate decreased. In addition, at the 50% concentrate level, numbers of protozoa increased, whereas numbers of methanogens, anaerobic fungi, and fibrolytic bacteria decreased. No interaction was noted between the 2 dietary factors on most variables, except that at the higher concentrate level the effects of BP on CH4 and CO2 formation per unit of NDF degraded, crude protein degradation, and the abundance of Prevotella were more prominent. In conclusion, the results of this study suggest that BP in the diet can adequately substitute CON with regard to ruminal fermentation profile and microbiota, showing even favorable fermentation patterns when fed at 50% inclusion rate. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. 76 FR 6335 - Sodium and Potassium Salts of N-alkyl (C8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ...): Solvents such as alcohols and hydrocarbons; surfactants such as polyoxyethylene polymers and fatty acids... metabolites are not systemically toxic and would be rapidly conjugated and excreted. The SSNA surfactants (mono and di-sodium propionates) may be conjugated and excreted directly. Alternatively, the tertiary...

  17. Cometabolism of DDT analogs by a Pseudomonas sp.

    PubMed Central

    Francis, A J; Spanggord, R J; Ouchi, G I; Bohonos, N

    1978-01-01

    A Pseudomonas sp. capable of growth on several nonchlorinated and mono-p-chloro-substituted analogs of DDT as a sole carbon source degraded bis(p-chlorophenyl)methane and 1,1-bis(p-chlorophenyl)ethane only in the presence of diphenylethane. The products p-chlorophenylacetic acid and 2-(p-chlorophenyl)-propionic acid were not further metabolized by the bacterium. Other chlorinated analogs of DDT were found to be recalcitrant to cometabolic degradation with diphenylethane. PMID:637537

  18. Top Value Added Chemicals from Biomass - Volume I, Results of Screening for Potential Candidates from Sugars and Synthesis Gas

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

    None

    2004-08-01

    This report identifies twelve building block chemicals that can be produced from sugars via biological or chemical conversions. The twelve building blocks can be subsequently converted to a number of high-value bio-based chemicals or materials. Building block chemicals, as considered for this analysis, are molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. The twelve sugar-based building blocks are 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol.

  19. Top Value Added Chemicals from Biomass: Volume I -- Results of Screening for Potential Candidates from Sugars and Synthesis Gas

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

    Werpy, T.; Petersen, G.

    2004-08-01

    This report identifies twelve building block chemicals that can be produced from sugars via biological or chemical conversions. The twelve building blocks can be subsequently converted to a number of high-value bio-based chemicals or materials. Building block chemicals, as considered for this analysis, are molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. The twelve sugar-based building blocks are 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol.

  20. Purification and fermentation in vitro of sesaminol triglucoside from sesame cake by human intestinal microbiota.

    PubMed

    Zhu, Xiuling; Zhang, Xin; Sun, Yongkang; Su, Di; Sun, Yi; Hu, Bing; Zeng, Xiaoxiong

    2013-02-27

    Sesaminol triglucoside (STG), the most abundant lignan glycoside existing in sesame cake/meal, has exhibited various biological activities. However, little information about its in vitro fermentation with intestinal microbiota is available. Therefore, the effect of STG from sesame cake on the fermentation of human fecal microbiota was evaluated. First, high-purity STG was successfully prepared from defatted sesame cake by extraction with 80% ethanol and simple purification procedures of polyamide column chromatography and Toyopearl HW-40S column chromatography. Then the influence of STG on intestinal microbiota was conducted by monitoring bacterial populations and analyzing the concentrations of short-chain fatty acids (SCFA). We found that STG could significantly induce an increase in numbers of Lactobacillus - Enterococcus group and Bifidobacterium in fermentation in vitro with human fecal microbiota, while it did not stimulate the bacterial growth of Eubacterium rectale - Clostridium coccoides group, Clostridium histolyticum group, and Bacteroides - Prevotella group. Furthermore, it was found that concentrations of formic, acetic, propionic, and butyric acids in STG culture increased significantly during the fermentation, and its total SCFA concentration was relatively higher than those of the control and glucose cultures at 6 and 12 h fermentation. Our findings provided further evidence for the importance of human intestinal bacteria in the bioactivity of STG and its metabolites in the maintenance of human health.

  1. In vitro fermentation and prebiotic potential of novel low molecular weight polysaccharides derived from agar and alginate seaweeds.

    PubMed

    Ramnani, Priya; Chitarrari, Roberto; Tuohy, Kieran; Grant, John; Hotchkiss, Sarah; Philp, Kevin; Campbell, Ross; Gill, Chris; Rowland, Ian

    2012-02-01

    Fermentation properties and prebiotic potential of novel low molecular weight polysaccharides (LMWPs) derived from agar and alginate bearing seaweeds was investigated. Ten LMWPs were supplemented to pH, temperature controlled anaerobic batch cultures inoculated with human feces from three donors, in triplicate. Microbiota changes were monitored using Fluorescent in-situ hybridization and short chain fatty acids, the fermentation end products were analysed using gas chromatography. Of the ten LMWPs tested, Gelidium seaweed CC2253 of molecular weight 64.64 KDa showed a significant increase in bifidobacterial populations from log(10) 8.06 at 0 h to log(10) 8.55 at 24 h (p = 0.018). For total bacterial populations, alginate powder CC2238 produced a significant increase from log(10) 9.01 at 0 h to log(10) 9.58 at 24 h (p = 0.032). No changes were observed in the other bacterial groups tested viz. Bacteroides, Lactobacilli/Enterococci, Eubacterium rectale/Clostridium coccoides and Clostridium histolyticum. The polysaccharides also showed significant increases in total SCFA production, particularly acetic and propionic acids, indicating that they were readily fermented. In conclusion, some LMWPs derived from agar and alginate bearing seaweeds were fermented by gut bacteria and exhibited potential to be used a novel source of prebiotics. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Chlorogenic acid versus amaranth's caffeoylisocitric acid - Gut microbial degradation of caffeic acid derivatives.

    PubMed

    Vollmer, Maren; Schröter, David; Esders, Selma; Neugart, Susanne; Farquharson, Freda M; Duncan, Sylvia H; Schreiner, Monika; Louis, Petra; Maul, Ronald; Rohn, Sascha

    2017-10-01

    The almost forgotten crop amaranth has gained renewed interest in recent years due to its immense nutritive potential. Health beneficial effects of certain plants are often attributed to secondary plant metabolites such as phenolic compounds. As these compounds undergo significant metabolism after consumption and are in most cases not absorbed very well, it is important to gain knowledge about absorption, biotransformation, and further metabolism in the human body. Whilst being hardly found in other edible plants, caffeoylisocitric acid represents the most abundant low molecular weight phenolic compound in many leafy amaranth species. Given that this may be a potentially bioactive compound, gastrointestinal microbial degradation of this substance was investigated in the present study by performing in vitro fermentation tests using three different fecal samples as inocula. The (phenolic) metabolites were analyzed using high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Furthermore, quantitative polymerase chain reaction (qPCR) analyses were carried out to study the influence on the microbiome and its composition. The in vitro fermentations led to different metabolite profiles depending on the specific donor. For example, the metabolite 3-(4-hydroxyphenyl)propionic acid was observed in one fermentation as the main metabolite, whereas 3-(3-hydroxyphenyl)propionic acid was identified in the other fermentations as important. A significant change in selected microorganisms of the gut microbiota however was not detected. In conclusion, caffeoylisocitric acid from amaranth, which is a source of several esterified phenolic acids in addition to chlorogenic acid, can be metabolized by the human gut microbiota, but the metabolites produced vary between individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Production and carcase traits in broiler chickens given diets supplemented with inorganic trivalent chromium and an organic acid blend.

    PubMed

    Samanta, S; Haldar, S; Ghosh, T K

    2008-03-01

    1. The study was conducted to ascertain the effects of supplemental organic acids and chromium (Cr) on production and carcase traits of broiler chickens. 2. A total of 120 1-d-old broiler chicks were divided into 4 treatment groups in a 2 x 2 factorial design (each treatment group contained 6 replicates with 5 birds per replicate). 3. The diets were supplemented with an organic acid blend containing ortho-phosphoric, formic and propionic acid and calcium propionate (1 g/kg diet) and inorganic trivalent chromium (Cr(3+)) as chromic chloride hexahydrate (0.5 mg/kg diet) either independently or together as a combination for 35 d. 4. Individual supplementation of organic acids and Cr(3+) and their combination significantly improved the food conversion ratio, hot and dressed carcase weight and weight of the wholesale cuts compared to the control group of birds. 5. Organic acids, either independently or along with Cr(3+), increased total accretion of ash in carcase. Protein accretion was improved by dietary Cr(3+) and organic acid supplementation compared to the control group and a further improvement in this regard was observed when Cr(3+) and organic acid were supplemented together. Across the treatment groups meat fat content and fat accretion were lower in birds receiving dietary Cr(3+) supplementation. 6. Circulatory Cr(3+) and meat Cr(3+) concentration increased compared to the other treatment groups when Cr(3+) was supplemented to the birds. 7. It was concluded that, instead of individual supplementation, a combination of Cr(3+) and organic acids may improve the production and carcase traits of broilers more effectively presumably because of an additive effect.

  4. Synthesis and biological evaluation of N-difluoromethyl-1,2-dihydropyrid-2-one acetic acid regioisomers: dual inhibitors of cyclooxygenases and 5-lipoxygenase.

    PubMed

    Yu, Gang; Praveen Rao, P N; Chowdhury, Morshed A; Abdellatif, Khaled R A; Dong, Ying; Das, Dipankar; Velázquez, Carlos A; Suresh, Mavanur R; Knaus, Edward E

    2010-04-01

    A new group of acetic acid (7a-c, R(1) = H), and propionic acid (7d-f, R(1) = Me), regioisomers wherein a N-difluoromethyl-1,2-dihydropyrid-2-one moiety is attached via its C-3, C-4, and C-5 position was synthesized. This group of compounds exhibited a more potent inhibition, and hence selectivity, for the cyclooxygenase-2 (COX-2) relative to the COX-1 isozyme. Attachment of the N-difluoromethyl-1,2-dihydropyrid-2-one ring system to an acetic acid, or propionic acid, moiety confers potent 5-LOX inhibitory activity, that is, absent in traditional arylacetic acid NSAIDs. 2-(1-Difluoromethyl-2-oxo-1,2-dihydropyridin-5-yl)acetic acid (7c) exhibited the best combination of dual COX-2 and 5-LOX inhibitory activities. Molecular modeling (docking) studies showed that the highly electronegative CHF(2) substituent present in 7c, that showed a modest selectivity for the COX-2 isozyme, is oriented within the secondary pocket (Val523) present in COX-2 similar to the sulfonamide (SO(2)NH(2)) COX-2 pharmacophore present in celecoxib, and that the N-difluoromethyl-1,2-dihydropyrid-2-one pharmacophore is oriented close to the region containing the LOX enzyme catalytic iron (His361, His366, and His545). Accordingly, the N-difluoromethyl-1,2-dihyrdopyrid-2-one moiety possesses properties suitable for the design of dual COX-2/5-LOX inhibitory drugs. 2010 Elsevier Ltd. All rights reserved.

  5. Interaction of bale size and preservative rate for large-round bales of alfalfa hay

    USDA-ARS?s Scientific Manuscript database

    Recently, two studies conducted at the US Dairy Forage Research Center have reported inconsistent storage responses following the application of propionic-acid-based preservatives to alfalfa or alfalfa-orchardgrass hays. One of these studies utilized 5-foot-diameter round bales, and produced disappo...

  6. Effectiveness of buffered propionic-acid preservatives for large hay packages

    USDA-ARS?s Scientific Manuscript database

    Most hay producers realize that hays packaged in large-round or large-square bales are particularly sensitive to spontaneous heating, dry matter losses, and negative changes in forage quality. During the last two decades, this has become an important dilemma for hay producers because the cost and av...

  7. The Resolution of Ibuprofen, 2-(4'-Isobutylphenyl) Propionic Acid

    ERIC Educational Resources Information Center

    McCullagh, James V.

    2008-01-01

    In this experiment the over-the-counter pain reliever ibuprofen is resolved using (S)-(-)-[alpha]-phenethylamine as the resolving agent. This procedure has several key advantages over previous resolution experiments. First, it involves the resolution of a well-known medicinal compound of commercial importance. Second, the resolution process is…

  8. 75 FR 78243 - Propionic Acid and Salts, Urea Sulfate, Methidathion, and Methyl Parathion; Registration Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-15

    ... intended function without causing unreasonable adverse effects on human health or the environment. Through... other knowledge, including its effects on human health and the environment. FOR FURTHER INFORMATION... general, and may be of interest to a wide range of stakeholders including environmental, human health...

  9. 75 FR 51055 - Propionic Acid and Salts, and Urea Sulfate; Registration Review Proposed Decisions; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... human health or the environment. Through this program, EPA is ensuring that each pesticide's registration is based on current scientific and other knowledge, including its effects on human health and the... range of stakeholders including environmental, human health, farm worker, and agricultural advocates...

  10. 21 CFR 1310.04 - Maintenance of records.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... kilogram. 8675 Ergonovine and its salts 10 grams. 8676 Ergotamine and its salts 20 grams. 8678 Ethylamine.... 8791 Phenylacetic acid, its esters, and its salts 1 kilogram. 2704 Piperidine and its salts 500 grams. 8750 Piperonal (also called heliotropine) 4 kilograms. 8328 Propionic anhydride 1 gram. 8323 Safrole 4...

  11. 21 CFR 1310.04 - Maintenance of records.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... kilogram. 8675 Ergonovine and its salts 10 grams. 8676 Ergotamine and its salts 20 grams. 8678 Ethylamine.... 8791 Phenylacetic acid, its esters, and its salts 1 kilogram. 2704 Piperidine and its salts 500 grams. 8750 Piperonal (also called heliotropine) 4 kilograms. 8328 Propionic anhydride 1 gram. 8323 Safrole 4...

  12. 21 CFR 1310.04 - Maintenance of records.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... kilogram. 8675 Ergonovine and its salts 10 grams. 8676 Ergotamine and its salts 20 grams. 8678 Ethylamine.... 8791 Phenylacetic acid, its esters, and its salts 1 kilogram. 2704 Piperidine and its salts 500 grams. 8750 Piperonal (also called heliotropine) 4 kilograms. 8328 Propionic anhydride 1 gram. 8323 Safrole 4...

  13. 21 CFR 1310.04 - Maintenance of records.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... kilogram. 8675 Ergonovine and its salts 10 grams. 8676 Ergotamine and its salts 20 grams. 8678 Ethylamine.... 8791 Phenylacetic acid, its esters, and its salts 1 kilogram. 2704 Piperidine and its salts 500 grams. 8750 Piperonal (also called heliotropine) 4 kilograms. 8328 Propionic anhydride 1 gram. 8323 Safrole 4...

  14. Transcriptome characterization by deep-RNA-sequencing underlies the mechanisms of butyrate-induced epigenomic regulation in bovine cells

    USDA-ARS?s Scientific Manuscript database

    Volatile short-chain fatty acids (SCFAs, acetate, propionate, and butyrate), especially butyrate, alter cell differentiation, proliferation, motility, and in particular, induce cell cycle arrest and apoptosis through its histone deacetylase (HDAC) inhibition activity. Butyrate is a great inducer of ...

  15. STIMULATION OF REDUCTIVE DECHLORINATION OF TETRA- CHLOROETHENE (PCE) IN ANAEROBIC AQUIFER MICROCOSMS BY ADDITION OF SHORT-CHAIN ORGANIC ACIDS OR ALCOHOLS

    EPA Science Inventory

    The effect of the addition of common fermentation products on the dehalogenation of tetrachloroethene was studied in methanogenic slurries made with aquifer solids. Lactate, propionate, crotonate, butyrate, and ethanol stimulated dehalogenation activity, while acetate, methanol, ...

  16. Field-Scale Treatability Study for Enhanced In Situ Bioremediation of Explosives in Groundwater: BioBarrier Installation and Hot Spot Treatment Using DPT Injection

    DTIC Science & Technology

    2012-05-24

    carbon is consumed, O2 is depleted until the system becomes anaerobic ►After O2 is consumed, anaerobic fermentation begins and H2 is released into...Degradation and TNT Biodegradation Pathway 10 Carbon source water Lactic acid propionic and pyruvic acids acetic acid fermentation methane TNT...A total of 32,791 lbs of SRS was mixed with potable water to provide 20,000 gallons of solution for injection ► 197 lbs of yeast extract was added

  17. Microwave-assisted rapid synthesis of methyl 2,4,5-trimethoxyphenylpropionate, a metabolite of Cordia alliodora.

    PubMed

    Sinha, A K; Joshi, B P; Sharma, A; Kumar, J K; Kaul, V K

    2003-12-01

    Microwave assisted condensation of asaronaldehyde (2) with malonic acid in piperidine-AcOH provides 2,4,5-trimethoxycinnamic acid (3) in 87% yield within 4 min, which upon further reduction with PdCl2- HCOOH-aq. NaOH gives 3-(2,4,5-trimethoxy)phenyl propionic acid (4) in 88% yield within 3 min. Esterification of 4 with MeOH-H+ gives methyl 2,4,5-trimethoxyphenylpropionate (1), a metabolite of Cordia alliodora, in 94% yield within 3 min (overall 69% yield).

  18. Insights on Alterations to the Rumen Ecosystem by Nitrate and Nitrocompounds

    PubMed Central

    Latham, Elizabeth A.; Anderson, Robin C.; Pinchak, William E.; Nisbet, David J.

    2016-01-01

    Nitrate and certain short chain nitrocompounds and nitro-oxy compounds are being investigated as dietary supplements to reduce economic and environmental costs associated with ruminal methane emissions. Thermodynamically, nitrate is a preferred electron acceptor in the rumen that consumes electrons at the expense of methanogenesis during dissimilatory reduction to an intermediate, nitrite, which is primarily reduced to ammonia although small quantities of nitrous oxide may also be produced. Short chain nitrocompounds act as direct inhibitors of methanogenic bacteria although certain of these compounds may also consume electrons at the expense of methanogenesis and are effective inhibitors of important foodborne pathogens. Microbial and nutritional consequences of incorporating nitrate into ruminant diets typically results in increased acetate production. Unlike most other methane-inhibiting supplements, nitrate decreases or has no effect on propionate production. The type of nitrate salt added influences rates of nitrate reduction, rates of nitrite accumulation and efficacy of methane reduction, with sodium and potassium salts being more potent than calcium nitrate salts. Digestive consequences of adding nitrocompounds to ruminant diets are more variable and may in some cases increase propionate production. Concerns about the toxicity of nitrate's intermediate product, nitrite, to ruminants necessitate management, as animal poisoning may occur via methemoglobinemia. Certain of the naturally occurring nitrocompounds, such as 3-nitro-1-propionate or 3-nitro-1-propanol also cause poisoning but via inhibition of succinate dehydrogenase. Typical risk management procedures to avoid nitrite toxicity involve gradually adapting the animals to higher concentrations of nitrate and nitrite, which could possibly be used with the nitrocompounds as well. A number of organisms responsible for nitrate metabolism in the rumen have been characterized. To date a single rumen bacterium is identified as contributing appreciably to nitrocompound metabolism. Appropriate doses of the nitrocompounds and nitrate, singly or in combination with probiotic bacteria selected for nitrite and nitrocompound detoxification activity promise to alleviate risks of toxicity. Further studies are needed to more clearly define benefits and risk of these technologies to make them saleable for livestock producers. PMID:26973609

  19. Microbiological, chemical, and sensory characteristics of Swiss cheese manufactured with adjunct Lactobacillus strains using a low cooking temperature.

    PubMed

    Kocaoglu-Vurma, N A; Harper, W J; Drake, M A; Courtney, P D

    2008-08-01

    The effect of nonstarter Lactobacillus adjunct cultures on the microbial, chemical, and sensory characteristics of Swiss cheese manufactured using the "kosher make procedure" was investigated. The kosher make procedure, which uses a lower cooking temperature than traditional Swiss cheese making, is used by many American cheese manufacturers to allow for kosher-certified whey. Cheeses were manufactured using a commercial starter culture combination and 1 of 3 non-starter Lactobacillus strains previously isolated from Swiss cheeses, Lactobacillus casei A26, L. casei B21, and Lactobacillus rhamnosus H2, as an adjunct. Control cheeses lacked the adjunct culture. Cheeses were analyzed during ripening for microbial and chemical composition. Adjunct strain L. casei A26, which utilized citrate most readily in laboratory medium, dominated the Lactobacillus population within 30 d, faster than the other adjunct cultures. There were no significant differences in Propionibacterium counts, Streptococcus thermophilus counts, protein, fat, moisture, salt, and pH among the cheeses. Free amino acid concentration ranged from 5 to 7 mmol/100 g of cheese at 90 d of ripening and was adjunct strain dependent. Lactic, acetic, and propionic acid concentrations were not significantly different among the cheeses after a 90-d ripening period; however differences in propionic acid concentrations were apparent at 60 d, with the cheeses made with L. casei adjuncts containing less propionic acid. Citric acid was depleted by the end of warm room ripening in cheeses manufactured with adjunct L. casei strains, but not with adjunct L. rhamnosus. Cheeses made with L. casei A26 were most similar to the control cheeses in diacetyl and butyric/isobutyric acid abundance as evaluated by electronic nose during the first 3 mo of ripening. The 4 cheese types differed in their descriptive sensory profiles at 8 mo of age, indicating an adjunct strain-dependent effect on particular flavor attributes. Adjunct Lactobacillus spp. affected the flavor profile and concentration of some flavor compounds in Swiss cheeses produced with the kosher make procedure. Use of adjunct Lactobacillus cultures provides Swiss cheese makers using a low cooking temperature with a means to control the dominant Lactobacillus strain during ripening, reduce citrate concentration, and modify cheese flavor.

  20. Shewanella halifaxensis sp. nov., a novel obligately respiratory and denitrifying psychrophile.

    PubMed

    Zhao, Jian-Shen; Manno, Dominic; Leggiadro, Cindy; O'Neil, David; Hawari, Jalal

    2006-01-01

    Indigenous bacteria found in the sediment of the Emerald Basin (depth of 215 m, Atlantic Ocean) located offshore of Halifax Harbour (Nova Scotia, Canada) were previously found to be able to degrade the explosive compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). In the present study, a novel obligately respiratory, denitrifying and RDX-mineralizing bacterium, designated strain HAW-EB4(T), was isolated from the marine sediment. This bacterium utilized peptone, yeast extract, Casamino acids, esters (Tweens 20, 40 and 80), sugars (N-acetyl-D-glucosamine, ribose), several C2 and C3 acids (acetate, pyruvate, lactate, propionate) and amino acids (serine, proline) as sole carbon and energy sources. Aerobically grown cells (in marine broth 2216 at 10 degrees C) contained C(14 : 0) (6 %), iso-C(15 : 0) (12 %), C(16 : 0) (20 %), C(16 : 1)omega7 (37 %), C(18 : 1)omega7 (7 %) and C(20 : 5)omega3 (7 %) as major membrane fatty acids, and Q7 (28.1 %) and MK-7 (60.9 %) as dominant respiratory quinones, consistent with deep-sea species of Shewanella. The novel bacterium had a DNA G+C content of 45 mol% and showed similarity to Shewanella species in terms of 16S rRNA and gyrB gene sequences (93-99 and 67.3-88.4 % similarity, respectively), with Shewanella pealeana being the most closely related species. Genomic DNA-DNA hybridization between strain HAW-EB4T and S. pealeana revealed a level of relatedness of 17.9 %, lower than the 70 % species cut-off value, indicating that strain HAW-EB4T (= NCIMB 14093T = DSM 17350T) is the type strain of a novel species of Shewanella, for which the name Shewanella halifaxensis sp. nov. is proposed.

  1. Survival of Acetate in Biodegraded Stream Water DOM: New Insights Based on NMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Whitty, S.; Waggoner, D. C.; Bowen, J. C.; Cory, R. M.; Kaplan, L.; Hatcher, P.

    2017-12-01

    DOM is a complex chemical mixture of high- (HMW) and low-molecular-weight (LMW) organic molecules that serve as the primary energy sources for heterotrophic bacteria in freshwater environments. However, there are still large uncertainties on the composition of DOM that is labile and thus rapidly metabolized. The current thinking is that labile DOM is primarily composed of monosaccharides, amino acids, and other LMW organic acids such as formic, acetic, or propionic among others, although some humic substances also are biologically labile. To test the contribution of LMW organic acids to the labile fraction of DOM, freshwater samples were collected from five streams within the Rio Tempisquito watershed in Costa Rica and subjected to differing degrees of biodegradation using a series of plug-flow bioreactors with residence times ranging from 0.5-150 min. Varying the residence times of bioreactors allows for separation and identification of labile from less labile to more recalcitrant DOM. The stream water fed into the bioreactors had DOC concentrations that ranged from 0.7-1.2 ppm C and the GF/F-filtered stream water as well as the bioreactor effluents were analyzed directly without pre-treatment using proton nuclear magnetic resonance spectroscopy (1H NMR). Small molecules dominated the 1H NMR spectra with the greatest changes, as a function of bioreactor residence time, in the carbohydrate, terminal methyl, and long-chain methylene structures. In contrast, acetate remained relatively constant after 150 min of bioreactor residence time, thus raising the question of why this inherently labile volatile fatty acid was not consumed by stream microbes colonizing bioreactors that otherwise metabolized approximately 35% of the total dissolved organic carbon present in the stream water. We suggest that acetate may resist biodegradation because it is complexed strongly with inorganic cations.

  2. Fermentation of cucumbers brined with calcium chloride instead of sodium chloride.

    PubMed

    McFeeters, Roger F; Pérez-Díaz, Ilenys

    2010-04-01

    Waste water containing high levels of NaCl from cucumber fermentation tank yards is a continuing problem for the pickled vegetable industry. A major reduction in waste salt could be achieved if NaCl were eliminated from the cucumber fermentation process. The objectives of this project were to ferment cucumbers in brine containing CaCl(2) as the only salt, to determine the course of fermentation metabolism in the absence of NaCl, and to compare firmness retention of cucumbers fermented in CaCl(2) brine during subsequent storage compared to cucumbers fermented in brines containing both NaCl and CaCl(2) at concentrations typically used in commercial fermentations. The major metabolite changes during fermentation without NaCl were conversion of sugars in the fresh cucumbers primarily to lactic acid which caused pH to decrease to less than 3.5. This is the same pattern that occurs when cucumbers are fermented with NaCl as the major brining salt. Lactic acid concentration and pH were stable during storage and there was no detectable production of propionic acid or butyric acid that would indicate growth of spoilage bacteria. Firmness retention in cucumbers fermented with 100 to 300 mM CaCl(2) during storage at a high temperature (45 degrees C) was not significantly different from that obtained in fermented cucumbers with 1.03 M NaCl and 40 mM CaCl(2). In closed jars, cucumber fermentations with and without NaCl in the fermentation brine were similar both in the chemical changes caused by the fermentative microorganisms and in the retention of firmness in the fermented cucumbers.

  3. 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

  4. Signal enhancement for gradient reverse-phase high-performance liquid chromatography-electrospray ionization mass spectrometry analysis with trifluoroacetic and other strong acid modifiers by postcolumn addition of propionic acid and isopropanol.

    PubMed

    Kuhlmann, F E; Apffel, A; Fischer, S M; Goldberg, G; Goodley, P C

    1995-12-01

    Trifluoroacetic acid (TFA) and other volatile strong acids, used as modifiers in reverse-phase high-performance liquid chromatography, cause signal suppression for basic compounds when analyzed by electrospray ionization mass spectrometry (ESI-MS). Evidence is presented that signal suppression is caused by strong ion pairing between the TFA anion and the protonated sample cation of basic sample molecules. The ion-pairing process "masks" the protonated sample cations from the ESI-MS electric fields by rendering them "neutral. " Weakly basic molecules are not suppressed by this process. The TFA signal suppression effect is independent from the well-known spray problem that electrospray has with highly aqueous solutions that contain TFA. This previously reported spray problem is caused by the high conductivity and surface tension of aqueous TFA solutions. A practical method to enhance the signal for most basic analytes in the presence of signal-suppressing volatile strong acids has been developed. The method employs postcolumn addition of a solution of 75% propionic acid and 25% isopropanol in a ratio 1:2 to the column flow. Signal enhancement is typically 10-50 times for peptides and other small basic molecules. Thus, peptide maps that use ESI-MS for detection can be performed at lower levels, with conventional columns, without the need to use capillary chromatography or reduced mass spectral resolution to achieve satisfactory sensitivity. The method may be used with similar results for heptafluorobutyric acid and hydrochloric acid. A mechanism for TFA signal suppression and signal enhancement by the foregoing method, is proposed.

  5. Animal fibre: the forgotten nutrient in strict carnivores? First insights in the cheetah.

    PubMed

    Depauw, S; Hesta, M; Whitehouse-Tedd, K; Vanhaecke, L; Verbrugghe, A; Janssens, G P J

    2013-02-01

    As wild felids are obligate carnivores, it is likely that poorly enzymatically digestible animal tissues determine hindgut fermentation, instead of plant fibre. Therefore, faecal concentrations of short-chain fatty acids (SCFA, including branched-chain fatty acids, BCFA), indole and phenol were evaluated in 14 captive cheetahs, fed two different diets differing in proportion of poorly enzymatically digestible animal tissue. Using a cross-over design, the cheetahs were fed exclusively whole rabbit or supplemented beef for 1 month each. Feeding whole rabbit decreased faecal propionic (p < 0.001) and butyric (p = 0.013) acid concentrations, yet total SCFA was unaltered (p = 0.146). Also, a remarkably higher acetic acid to propionic acid ratio (p = 0.013) was present when fed whole rabbit. Total BCFA (p = 0.011) and putrefactive indole (p = 0.004) and phenol (p = 0.002) were lower when fed whole rabbit. Additionally, serum indoxyl sulphate, a toxic metabolite of indole, was analysed and showed a quadratic decrease (p = 0.050) when fed whole rabbit. The divergent SCFA ratios and the decrease in putrefaction when fed whole rabbit could be caused by the presence of undigested tissue, such as skin, bone and cartilage, that might have fibre-like functions. The concept of animal fibre is an unexplored area of interest relevant to gastrointestinal health of captive cheetahs and likely other felids. © 2011 Blackwell Verlag GmbH.

  6. Transition metal ion-assisted photochemical generation of alkyl halides and hydrocarbons from carboxylic acids.

    PubMed

    Carraher, Jack M; Pestovsky, Oleg; Bakac, Andreja

    2012-05-21

    Near-UV photolysis of aqueous solutions of propionic acid and aqueous Fe(3+) in the absence of oxygen generates a mixture of hydrocarbons (ethane, ethylene and butane), carbon dioxide, and Fe(2+). The reaction becomes mildly catalytic (about five turnovers) in the presence of oxygen which converts a portion of alkyl radicals to oxidizing intermediates that reoxidize Fe(2+). The photochemistry in the presence of halide ions (X(-) = Cl(-), Br(-)) generates ethyl halides via halogen atom abstraction from FeX(n)(3-n) by ethyl radicals. Near-quantitative yields of C(2)H(5)X are obtained at ≥0.05 M X(-). Competition experiments with Co(NH(3))(5)Br(2+) provided kinetic data for the reaction of ethyl radicals with FeCl(2+) (k = (4.0 ± 0.5) × 10(6) M(-1) s(-1)) and with FeBr(2+) (k = (3.0 ± 0.5) × 10(7) M(-1) s(-1)). Photochemical decarboxylation of propionic acid in the presence of Cu(2+) generates ethylene and Cu(+). Longer-chain acids also yield alpha olefins as exclusive products. These reactions become catalytic under constant purge with oxygen which plays a dual role. It reoxidizes Cu(+) to Cu(2+), and removes gaseous olefins to prevent accumulation of Cu(+)(olefin) complexes and depletion of Cu(2+). The results underscore the profound effect that the choice of metal ions, the medium, and reaction conditions exert on the photochemistry of carboxylic acids.

  7. Urinary excretion of Citrus flavanones and their major catabolites after consumption of fresh oranges and pasteurized orange juice: A randomized cross-over study.

    PubMed

    Aschoff, Julian K; Riedl, Ken M; Cooperstone, Jessica L; Högel, Josef; Bosy-Westphal, Anja; Schwartz, Steven J; Carle, Reinhold; Schweiggert, Ralf M

    2016-12-01

    Orange juice contains flavanones including hesperidin and narirutin, albeit at lower concentrations as compared to orange fruit. Therefore, we compared bioavailability and colonic catabolism of flavanones from orange juice to a 2.4-fold higher dose from fresh oranges. Following a randomized two-way cross-over design, 12 healthy subjects consumed a test meal comprising either fresh oranges or pasteurized orange juice, delivering 1774 and 751 μmol of total Citrus flavanones, respectively. Deglucuronidated and desulfated hesperetin, naringenin, and the flavanone catabolites 3-(3'-hydroxy-4'-methoxyphenyl)propionic acid, 3-(3'-hydroxyphenyl)hydracrylic acid, 4-hydroxyhippuric acid, and hippuric acid were quantitated in 24-h urine by UHPLC-MS/MS. Differences in urinary hesperetin excretion were found to be nonsignificant (p = 0.5209) both after consumption of orange fruit (21.6 ± 8.0 μmol) and juice (18.3 ± 7.2 μmol). By analogy, postprandial flavanone catabolite excretions were highly similar between treatments. Excretion of 3-(3'-hydroxy-4'-methoxyphenyl)propionic acid was inversely related to that of hesperetin, illustrating the catabolite/precursor relationship. Despite 2.4-fold higher doses, excretion of flavanones from ingested fresh orange fruit did not differ from that following orange juice consumption, possibly due to a saturation of absorption or their entrapment in the fiber-rich matrix of the fruit. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Predicting the combinatorial effects of water activity, pH and organic acids on Listeria growth in media and complex food matrices.

    PubMed

    Nyhan, L; Begley, M; Mutel, A; Qu, Y; Johnson, N; Callanan, M

    2018-09-01

    The aim of this study was to develop a model to predict growth of Listeria in complex food matrices as a function of pH, water activity and undissociated acetic and propionic acid concentration i.e. common food hurdles. Experimental growth curves of Listeria in food products and broth media were collected from ComBase, the literature and industry sources from which a bespoke secondary gamma model was constructed. Model performance was evaluated by comparing predictions to measured growth rates in growth media (BHI broth) and two adjusted food matrices (zucchini purée and béarnaise sauce). In general, observed growth rates were higher in broth than in the food matrices which resulted in the model over-estimating growth in the adjusted food matrices. In addition, model outputs were more accurate for conditions without acids, indicating that the organic acid component of the model was a source of inaccuracy. In summary, a new predictive growth model for innovating or renovating food products that rely on multi-hurdle technology was created. This study is the first to report on modelling of propionic acid as an inhibitor of Listeria in combination with other hurdles. Our findings provide valuable insights into predictive model design and performance and highlight the importance of experimental validation of models in real food matrices rather than laboratory media alone. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Rumen volatile fatty acids and milk composition from cows fed hay, haylage, or urea-treated corn silage.

    PubMed

    Schingoethe, D J; Voelker, H H; Beardsley, G L; Parsons, J G

    1976-05-01

    Alfalfa-brome hay, haylage, .5% urea-treated corn silage, or .5% urea plus 1% dried whey-treated corn silage was fed as the only forage to one of four groups of 10 lactating cows per group for a lactation trial of 10 wk. Rumen samples were collected via stomach tube 3 to 4 h after the morning feeding. The pH of the rumen samples from cows fed hay was higher than for cows fed haylage, urea-treated corn silage, and urea-whey corn silage, 6.69 versus 6.36, 6.40, and 6.50. Total volatile fatty acids and propionate were highest from cows fed urea-whey corn silage and were higher on all three fermented forages than cows fed hay. Acetate/propionate ratio was highest from cows fed hay and lowest from cows fed corn silages. Butyrate was highest from cows fed haylage or hay. Milk protein composition was not affected by ration although nonprotein nitrogen of milk was highest from cows fed the urea-treated corn silages. Oleic acid and total unsaturated fatty acids were lowest in milk fat from cows fed hay while palmitic acid was highest from cows fed hay and haylage. These results suggest that type of forage fed may cause small changes in rumen fermentation and in milk composition. The importance of these changes is unknown but may affect properties of dairy products produced from this milk.

  10. Short chain aliphatic acid anions in oil field waters and their contribution to the measured alkalinity

    USGS Publications Warehouse

    Willey, L.M.; Kharaka, Y.K.; Presser, T.S.; Rapp, J.B.; Barnes, I.

    1975-01-01

    High alkalinity values found in some formation waters from Kettleman North Dome oil field are due chiefly to acetate and propionate ions, with some contribution from higher molecular weight organic acid ions. Some of these waters contain no detectable bicarbonate alkalinity. For waters such as these, high supersaturation with respect to calcite will be incorrectly indicated by thermodynamic calculations based upon carbonate concentrations inferred from traditional alkalinity measurements. ?? 1975.

  11. Effect of volatile fatty acids in anaerobic conditions on viability of helminth ova (Ascaris suum) in sanitization of municipal sludge.

    PubMed

    Rojas-Oropeza, Marcelo; Hernández-Uresti, Alejandro S; Ortega-Charleston, Luis S; Cabirol, Nathalie

    2017-09-01

    The present work aimed at evaluating the effect of four different mixtures of diverse volatile fatty acids (VFAs) on the viability of helminth ova (Ascaris suum), under mesophilic (35°C) anaerobic conditions and at different incubation times, in order to reproduce the process of two-phase anaerobic digestion. The mixtures of VFAs contained acetic, propionic, butyric, valeric, and isovaleric acids, used at concentrations normally found in acidogenic anaerobic digesters. The four treatments all showed a reduction in Ascaris suum ova viability, among which Treatment III (4.2 g-acetic acid L -1  +  2.2 g-propionic acid L -1  + 0.6 g-valeric acid L -1  + 0.6 g-isovaleric acid L -1 ) resulted the most efficient. We found that the full effect of VFAs on the viability loss of Ascaris suum ova in mesophilic conditions requires a minimum incubation time of 3 days. The highest efficiency in the loss of viability was observed with Treatment III and 4-day incubation. Interestingly, the proportion of acetic acid was three times as much in this treatment than in the other ones and resulted in an effect in a minimum time of 3 days. The mesophilic condition, however, was not sufficient to induce a complete loss of viability.

  12. Aminiphilus circumscriptus gen. nov., sp. nov., an anaerobic amino-acid-degrading bacterium from an upflow anaerobic sludge reactor.

    PubMed

    Díaz, C; Baena, S; Fardeau, M-L; Patel, B K C

    2007-08-01

    Strain ILE-2(T) was isolated from an upflow anaerobic sludge bed reactor treating brewery wastewater. The motile, non-sporulating, slightly curved cells (2-4 x 0.1 microm) stained Gram-negative and grew optimally at 42 degrees C and pH 7.1 with 0.5 % NaCl. The strain required yeast extract for growth and fermented Casamino acids, peptone, isoleucine, arginine, lysine, alanine, valine, glutamate, histidine, glutamine, methionine, malate, fumarate, glycerol and pyruvate to acetate, propionate and minor amounts of branched-chain fatty acids. Carbohydrates, formate, acetate, propionate, butyrate, isovalerate, methanol, ethanol, 1-propanol, butanol, lactate, succinate, starch, casein, gelatin, xylan and a number of other amino acids were not utilized. The DNA G+C content of strain ILE-2(T) was 52.7 mol%. 16S rRNA gene sequence analysis revealed that ILE-2(T) was distantly related to members of the genera Aminobacterium (83 % similarity) and Aminomonas (85 % similarity) in the family Syntrophomonadaceae, order Clostridiales, phylum Firmicutes. On the basis of the results of our polyphasic analysis, strain ILE-2(T) represents a novel species and genus within the family Syntrophomonadaceae, for which the name Aminiphilus circumscriptus gen. nov., sp. nov. is proposed. The type strain of Aminiphilus circumscriptus is ILE-2(T) (=DSM 16581(T) =JCM 14039(T)).

  13. Potential of biohydrogen production from effluents of citrus processing industry using anaerobic bacteria from sewage sludge.

    PubMed

    Torquato, Lilian D M; Pachiega, Renan; Crespi, Marisa S; Nespeca, Maurílio Gustavo; de Oliveira, José Eduardo; Maintinguer, Sandra I

    2017-01-01

    Citrus crops are among the most abundant crops in the world, which processing is mainly based on juice extraction, generating large amounts of effluents with properties that turn them into potential pollution sources if they are improperly discarded. This study evaluated the potential for bioconversion of effluents from citrus-processing industry (wastewater and vinasse) into hydrogen through the dark fermentation process, by applying anaerobic sewage sludge as inoculum. The inoculum was previously heat treated to eliminate H 2 -consumers microorganisms and improve its activity. Anaerobic batch reactors were operated in triplicate with increasing proportions (50, 80 and 100%) of each effluent as substrate at 37°C, pH 5.5. Citrus effluents had different effects on inoculum growth and H 2 yields, demonstrated by profiles of acetic acid, butyric acid, propionic acid and ethanol, the main by-products generated. It was verified that there was an increase in the production of biogas with the additions of either wastewater (7.3, 33.4 and 85.3mmolL -1 ) or vinasse (8.8, 12.7 and 13.4mmolL -1 ) in substrate. These effluents demonstrated remarkable energetic reuse perspectives: 24.0MJm -3 and 4.0MJm -3 , respectively. Besides promoting the integrated management and mitigation of anaerobic sludge and effluents from citrus industry, the biohydrogen production may be an alternative for the local energy supply, reducing the operational costs in their own facilities, while enabling a better utilization of the biological potential contained in sewage sludges. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Characterization of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time.

    PubMed

    Nath, Caroline Daiane; Neres, Marcela Abbado; Scheidt, Kácia Carine; Bersot, Luciano Dos Santos; Sunahara, Samantha Mariana Monteiro; Sarto, Jaqueline Rocha Wobeto; Stangarlin, José Renato; Gomes, Simone Damasceno; Sereno, Mallu Jagnow; Perin, Ana Paula

    2018-03-02

    The objective was to characterize the fermentative and microbiological profile of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time. The experimental design consisted of a randomized block design with four and six wrapping layers (100 and 150 microns in total. respectively) allocated in the main plots, through repeated measures analysis (30, 60, and 90 days of storage) with four replicates. The storage time and number of wrapping layers did not show changes in the population of Clostridium and lactic acid bacteria. A decrease was observed in the enterobacteria population with an increase in the storage period in the two wrapping layers studied. Upon opening of the haylage at 30 days, the population of Bacillus was lower in haylages made with six layers of wrapping (3.63 log colony forming units (CFU) g-1). No growth of Listeria sp. or Salmonella sp. was observed during the experimental period. The fungal genera with greater occurrence were Penicillium sp. and Fusarium sp. The following mycotoxins were not detected: ochratoxin A, fumonisins, and zearalenone. Relative to the organic butyric, propionic, and acetic acids, the haylages presented a low concentration of lactic acid; this may have prevented a drop in the pH, which was high when the silos were opened (5.4). The levels of ammoniacal nitrogen and soluble carbohydrates presented no variation among the number of wrapping layers, with an overall average of 35.55 and 38.04 g kg-1. Tifton 85 bermudagrass haylage wrapped with four and six layers presented adequate fermentation and microbiological characteristics in the evaluated periods.

  15. Contribution of acidic components to the total acid number (TAN) of bio-oil

    DOE PAGES

    Park, Lydia K-E.; Liu, Jiaojun; Yiacoumi, Sotira; ...

    2017-03-28

    Bio-oil or pyrolysis oil — a product of thermochemical decomposition of biomass under oxygen-limited conditions — holds great potential to be a substitute for nonrenewable fossil fuels. But, its high acidity, which is primarily due to the degradation of hemicelluloses, limits its applications. For the evaluation of bio-oil production and treatment, it is essential to accurately measure the acidity of bio-oil. The total acid number (TAN), which is defined as the amount of potassium hydroxide needed to titrate one gram of a sample and has been established as an ASTM method to measure the acidity of petroleum products, has beenmore » employed to investigate the acidity of bio-oil. The TAN values of different concentrations of bio-oil components such as standard solutions of acetic acid, propionic acid, vanillic acid, hydroxybenzoic acid, syringic acid, hydroxymethylfurfural, and phenol were analyzed according to the ASTM D664 standard method. Our method showed the same linear relationship between the TAN values and the molar concentrations of acetic, propionic, and hydroxybenzoic acids. A different linear relationship was found for vanillic acid, due to the presence of multiple functional groups that can contribute to the TAN value. Furthermore, the influence of the titration solvent on the TAN values has been determined by comparing the TAN values and titration curves obtained from the standard method with results from the TAN analysis in aqueous environment and with equilibrium modeling results. Aqueous bio-oil samples with a known amount of acetic acid added were also analyzed. The additional acetic acid in bio-oil samples caused a proportional increase in the TAN values. These results of this research indicate that the TAN value of a sample with acids acting as monoprotic acids in the titration solvent can be converted to the molar concentration of total acids. For a sample containing acids that act as diprotic and polyprotic acids, however, its TAN value cannot be simply converted to the molar concentration of total acids because these acids have a stronger contribution to the TAN values than the contribution of monoprotic acids.« less

  16. Contribution of acidic components to the total acid number (TAN) of bio-oil

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

    Park, Lydia K-E.; Liu, Jiaojun; Yiacoumi, Sotira

    Bio-oil or pyrolysis oil — a product of thermochemical decomposition of biomass under oxygen-limited conditions — holds great potential to be a substitute for nonrenewable fossil fuels. But, its high acidity, which is primarily due to the degradation of hemicelluloses, limits its applications. For the evaluation of bio-oil production and treatment, it is essential to accurately measure the acidity of bio-oil. The total acid number (TAN), which is defined as the amount of potassium hydroxide needed to titrate one gram of a sample and has been established as an ASTM method to measure the acidity of petroleum products, has beenmore » employed to investigate the acidity of bio-oil. The TAN values of different concentrations of bio-oil components such as standard solutions of acetic acid, propionic acid, vanillic acid, hydroxybenzoic acid, syringic acid, hydroxymethylfurfural, and phenol were analyzed according to the ASTM D664 standard method. Our method showed the same linear relationship between the TAN values and the molar concentrations of acetic, propionic, and hydroxybenzoic acids. A different linear relationship was found for vanillic acid, due to the presence of multiple functional groups that can contribute to the TAN value. Furthermore, the influence of the titration solvent on the TAN values has been determined by comparing the TAN values and titration curves obtained from the standard method with results from the TAN analysis in aqueous environment and with equilibrium modeling results. Aqueous bio-oil samples with a known amount of acetic acid added were also analyzed. The additional acetic acid in bio-oil samples caused a proportional increase in the TAN values. These results of this research indicate that the TAN value of a sample with acids acting as monoprotic acids in the titration solvent can be converted to the molar concentration of total acids. For a sample containing acids that act as diprotic and polyprotic acids, however, its TAN value cannot be simply converted to the molar concentration of total acids because these acids have a stronger contribution to the TAN values than the contribution of monoprotic acids.« less

  17. Indole-3-acetic acid UDP-glucosyltransferase from immature seeds of pea is involved in modification of glycoproteins.

    PubMed

    Ostrowski, Maciej; Hetmann, Anna; Jakubowska, Anna

    2015-09-01

    The glycosylation of auxin is one of mechanisms contributing to hormonal homeostasis. The enzyme UDPG: indole-3-ylacetyl-β-D-glucosyltransferase (IAA glucosyltransferase, IAGlc synthase) catalyzes the reversible reaction: IAA+UDPG↔1-O-IA-glucose+UDP, which is the first step in the biosynthesis of IAA-ester conjugates in monocotyledonous plants. In this study, we report IAA-glucosyltransferase isolated using a biochemical approach from immature seed of pea (Pisum sativum). The enzyme was purified by PEG fractionation, DEAE-Sephacel anion-exchange chromatography and preparative PAGE. LC-MS/MS analysis of tryptic peptides of the enzyme revealed the high identity with maize IAGlc synthase, but lack of homology with other IAA-glucosyltransferases from dicots. Biochemical characterization showed that of several acyl acceptors tested, the enzyme had the highest activity on IAA as the glucosyl acceptor (Km=0.52 mM, Vmax=161 nmol min(-1), kcat/Km=4.36 mM s(-1)) and lower activity on indole-3-propionic acid and 1-naphthalene acetic acid. Whereas indole-3-butyric acid and indole-3-propionic acid were competitive inhibitors of IAGlc synthase, D-gluconic acid lactone, an inhibitor of β-glucosidase activity, potentiated the enzyme activity at the optimal concentration of 0.3mM. Moreover, we demonstrated that the 1-O-IA-glucose synthesized by IAGlc synthase is the substrate for IAA labeling of glycoproteins from pea seeds indicating a possible role of this enzyme in the covalent modification of a class of proteins by a plant hormone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Systemic exposure and urinary cortisol effects of fluticasone propionate formulated with hydrofluoroalkane in 4- to 11-year-olds with asthma.

    PubMed

    Kim, Kenneth T; Milgrom, Henry; Yoon, Y Kellie; Levy, Arden L; Matz, Paul; Welch, Michael J; Cahn, Anthony; Collins, David A; Kathman, Steven; Mehta, Rashmi; Su, Sheng-Fang; Kunka, Robert L

    2008-01-01

    The systemic exposure of fluticasone propionate with hydrofluoroalkane propellant compared with chlorofluoro-carbon propellant and the effect of fluticasone propionate hydrofluoroalkane on 24-hour urinary cortisol in children aged 4 to 11 years with asthma were evaluated. Study 1 was an open-label, 2-way crossover study in which 16 subjects were randomized to 7.5 days each of fluticasone propionate hydrofluoroalkane 88 mug twice a day or fluticasone propionate chlorofluorocarbon 88 mug twice a day. In study 2, 63 subjects received 13.5 days of placebo followed by 27.5 days of fluticasone propionate hydrofluoroalkane 88 mug twice a day. The main outcome measure for study 1 was the difference between fluticasone propionate hydrofluoroalkane and fluticasone propionate chlorofluorocarbon in fluticasone propionate AUC(last) (area under the plasma fluticasone propionate concentration-time curve from zero up to the last quantifiable plasma concentration), and for study 2, 24-hour overnight urinary cortisol excretion. In study 1, fluticasone propionate systemic exposure was significantly lower (55%) with hydrofluoroalkane metered dose inhaler compared with chlorofluorocarbon metered dose inhaler. Study 2 showed no statistically significant changes in 24-hour overnight urinary cortisol excretion and no relationship to fluticasone propionate systemic exposure at this dose. The results of these 2 studies showed that in children aged 4 to 11 years with asthma, fluticasone propionate hydrofluoroalkane has lower systemic exposure compared with chlorofluorocarbon and no hypothalamic-pituitary-adrenal axis effects as measured by 24-hour urinary cortisol excretion.

  19. Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure

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

    Ye, Jingqing; School of Environmental Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275; Li, Dong

    Highlights: • Biogas production was enhanced by co-digestion of rice straw with other materials. • The optimal ratio of kitchen waste, pig manure and rice straw is 0.4:1.6:1. • The maximum biogas yield of 674.4 L/kg VS was obtained. • VFA inhibition occurred when kitchen waste content was more than 26%. • The dominant VFA were propionate and acetate in successful reactors. - Abstract: In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37 ± 1 °C)more » anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others.« less

  20. Ruminal fermentation of anti-methanogenic nitrate- and nitro-containing forages in vitro

    USDA-ARS?s Scientific Manuscript database

    Nitrate, 3-nitro-1-propionic acid (NPA), and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if fed at high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied li...

  1. Effect of sole or combined administration of nitrate and 3-nitro-1-propionic acid on fermentation and Salmonella survivability in alfalfa-fed rumen cultures in vitro.

    PubMed

    Correa, Alejandro Castañeda; Trachsel, Julian; Allen, Heather K; Corral-Luna, Agustin; Gutierrez-Bañuelos, Hector; Ochoa-Garcia, Pedro Antonia; Ruiz-Barrera, Oscar; Hume, Michael E; Callaway, Todd R; Harvey, Roger B; Beier, Ross C; Anderson, Robin C; Nisbet, David J

    2017-04-01

    Ruminal methanogenesis is a digestive inefficiency resulting in the loss of dietary energy consumed by the host and contributing to environmental methane emission. Nitrate is being investigated as a feed supplement to reduce rumen methane emissions but safety and efficacy concerns persist. To assess potential synergies of co-administering sub-toxic amounts of nitrate and 3-nitro-1-propionate (NPA) on fermentation and Salmonella survivability with an alfalfa-based diet, ruminal microbes were cultured with additions of 8 or 16mM nitrate, 4 or 12mM NPA or their combinations. All treatments decreased methanogenesis compared to untreated controls but volatile fatty acid production and fermentation of hexose were also decreased. Nitrate was converted to nitrite, which accumulated to levels inhibitory to digestion. Salmonella populations were enriched in nitrate only-treated cultures but not in cultures co- or solely treated with NPA. These results reveal a need for dose optimization to safely reduce methane production with forage-based diets. Published by Elsevier Ltd.

  2. Modeling the dynamic volatile fatty acids profiles with pH and hydraulic retention time in an anaerobic baffled reactor during the startup period.

    PubMed

    Shi, En; Li, Jianzheng; Leu, Shao-Yuan; Antwi, Philip

    2016-12-01

    To predict the dynamic profiles in volatile fatty acids (VFAs) with pH and hydraulic retention time (HRT) during the startup of a 4-compartment ABR, a mathematical model was constructed by introducing pH and thermodynamic inhibition functions into the biochemical processes derived from the ADM1. The calibration of inhibition parameter for propionate uptake effectively improved the prediction accuracy of VFAs. The developed model could simulate the VFAs profiles very well no matter the observable change of pH or/and HRT. The simulation results indicated that both H 2 -producing acetogenesis and methanogenesis in the ABR would be inhibited with a pH less than 4.61, and the propionate oxidation could be thermodynamically restricted even with a neutral pH. A decreased HRT would enhanced the acidogenesis and H 2 -producing acetogenesis in the first 3 compartments, but no observable increase in effluent VFAs could be found due to the synchronously enhanced methanogenesis in the last compartment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Full-scale and laboratory-scale anaerobic treatment of citric acid production wastewater.

    PubMed

    Colleran, E; Pender, S; Philpott, U; O'Flaherty, V; Leahy, B

    1998-01-01

    This paper reviews the operation of a full-scale, fixed-bed digester treating a citric acid production wastewater with a COD:sulphate ratio of 3-4:1. Support matrix pieces were removed from the digester at intervals during the first 5 years of operation in order to quantify the vertical distribution of biomass within the digester. Detailed analysis of the digester biomass after 5 years of operation indicated that H2 and propionate-utilising SRB had outcompeted hydrogenophilic methanogens and propionate syntrophs. Acetoclastic methanogens were shown to play the dominant role in acetate conversion. Butyrate and ethanol-degrading syntrophs also remained active in the digester after 5 years of operation. Laboratory-scale hybrid reactor treatment at 55 degrees C of a diluted molasses influent, with and without sulphate supplementation, showed that the reactors could be operated with high stability at volumetric loading rates of 24 kgCOD.m-3.d-1 (12 h HRT). In the presence of sulphate (2 g/l-1; COD/sulphate ratio of 6:1), acetate conversion was severely inhibited, resulting in effluent acetate concentrations of up to 4000 mg.l-1.

  4. Feed supplementation with red seaweeds, Chondrus crispus and Sarcodiotheca gaudichaudii, affects performance, egg quality, and gut microbiota of layer hens.

    PubMed

    Kulshreshtha, Garima; Rathgeber, Bruce; Stratton, Glenn; Thomas, Nikhil; Evans, Franklin; Critchley, Alan; Hafting, Jeff; Prithiviraj, Balakrishnan

    2014-12-01

    The aim of this study was to evaluate the effect of the inclusion of red seaweed supplementation to standard poultry diets on production performance, egg quality, intestinal histology, and cecal short-chain fatty acids in Lohmann Brown Classic laying hens. A total of 160 birds were randomly assigned to 8 treatment groups. Control hens were fed a basal layer diet; positive control hens were fed a diet containing 2% inulin; and 6 treatment groups were fed a diet containing one of the following; 0.5, 1, or 2% Chondrus crispus (CC0.5, CC1, and CC2, respectively) and one of the same 3 levels of Sarcodiotheca gaudichaudii (SG0.5, SG1, and SG2, respectively). Dietary supplementation had no significant effect on the feed intake, BW, egg production, fecal moisture content, and blood serum profile of the birds. The feed conversion ratio per gram of egg was significantly more efficient (P = 0.001) for CC2 and SG2 treatments. Moreover, SG1 supplementation increased egg yolk weight (P = 0.0035) and birds with CC1 supplementation had higher egg weight (P = 0.0006). The SG2 and CC2 groups had greater (P < 0.05) villus height and villus surface area compared with the control birds. Seaweed supplementation increased the abundance of beneficial bacteria [e.g., Bifidobacterium longum (4- to 14-fold), Streptococcus salivarius (4- to 15-fold)] and importantly reduced the prevalence of Clostridium perfringens in the gut of the chicken. Additionally, the concentrations of short-chain fatty acids, including acetic acid, propionic acid, n-butyric acid, and i-butyric acid, were significantly higher (P < 0.05) in CC and SG treatments than in the control. In conclusion, dietary supplementation using red seaweed inclusions can act as a potential prebiotic to improve performance, egg quality, and overall gut health in layer hens. ©2014 Poultry Science Association Inc.

  5. 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

  6. 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

  7. Alternative energy production pathways in Taenia crassiceps cysticerci in vitro exposed to a benzimidazole derivative (RCB20).

    PubMed

    Fraga, Carolina Miguel; Da Costa, Tatiane Luiza; De Castro, Ana Maria; Reynoso-Ducoing, Olivia; Ambrosio, Javier; Hernández-Campos, Alicia; Castillo, Rafael; Vinaud, Marina Clare

    2016-04-01

    Biochemical studies of benzimidazole derivatives are important to determine their mode of action and activity against parasites. The lack of antihelminthic alternatives to treat parasitic infections and albendazole resistance cases make the search for new antiparasitary drugs of utmost importance. The 6-chloro-5-(1-naphthyloxy)-2-(trifluoromethyl)-1H-benzimidazole (RCB20) is a benzimidazole derivative with promising effect. This study evaluated the effect of different concentrations of RCB20 in the alternative energetic pathway of in vitro Taenia crassiceps cysticerci. The parasites were in vitro exposed to 6.5 and 13 µM of RCB20 and albendazole sulfoxide (ABZSO). The quantification of acetate, acetoacetate, β-hydroxybutyrate, fumarate and propionate was performed by high-performance liquid chromatography. The quantification of urea, creatinine and total proteins was performed by spectrophotometry. The increase in β-hydroxybutyrate reflects the enhancement of the fatty acid oxidation in the treated groups. Volatile fatty acids secretion, acetate and propionate, was increased in the treated groups. The secretion mechanisms of the treated parasites were impaired due to organic acids increased concentrations in the cysticerci. It is possible to conclude that the metabolic effect on alternative energetic pathways is slightly increased in the parasites treated with RCB20 than the ones treated with ABZSO.

  8. Rett Syndrome: A Focus on Gut Microbiota

    PubMed Central

    Borghi, Elisa; Borgo, Francesca; Severgnini, Marco; Savini, Miriam Nella; Casiraghi, Maria Cristina; Vignoli, Aglaia

    2017-01-01

    Rett syndrome (RTT) is an X-linked neurodevelopmental disorder affecting 1 in 10,000 live female births. Changes in microbiota composition, as observed in other neurological disorders such as autism spectrum disorders, may account for several symptoms typically associated with RTT. We studied the relationship between disease phenotypes and microbiome by analyzing diet, gut microbiota, and short-chain fatty acid (SCFA) production. We enrolled eight RTT patients and 10 age- and sex-matched healthy women, all without dietary restrictions. The microbiota was characterized by 16S rRNA gene sequencing, and SCFAs concentration was determined by gas chromatographic analysis. The RTT microbiota showed a lower α diversity, an enrichment in Bacteroidaceae, Clostridium spp., and Sutterella spp., and a slight depletion in Ruminococcaceae. Fecal SCFA concentrations were similar, but RTT samples showed slightly higher concentrations of butyrate and propionate, and significant higher levels in branched-chain fatty acids. Daily caloric intake was similar in the two groups, but macronutrient analysis showed a higher protein content in RTT diets. Microbial function prediction suggested in RTT subjects an increased number of microbial genes encoding for propionate and butyrate, and amino acid metabolism. A full understanding of these critical features could offer new, specific strategies for managing RTT-associated symptoms, such as dietary intervention or pre/probiotic supplementation. PMID:28178201

  9. Effects of Aspergillus Oryzae Culture and 2-Hydroxy-4-(Methylthio)-Butanoic Acid on In vitro Rumen Fermentation and Microbial Populations between Different Roughage Sources.

    PubMed

    Sun, H; Wu, Y M; Wang, Y M; Liu, J X; Myung, K H

    2014-09-01

    An in vitro experiment was conducted to evaluate the effects of Aspergillus oryzae culture (AOC) and 2-hydroxy-4-(methylthio)-butanoic acid (HMB) on rumen fermentation and microbial populations between different roughage sources. Two roughage sources (Chinese wild rye [CWR] vs corn silage [CS]) were assigned in a 2×3 factorial arrangement with HMB (0 or 15 mg) and AOC (0, 3, or 6 mg). Gas production (GP), microbial protein (MCP) and total volatile fatty acid (VFA) were increased in response to addition of HMB and AOC (p<0.01) for the two roughages. The HMB and AOC showed inconsistent effects on ammonia-N with different substrates. For CWR, neither HMB nor AOC had significant effect on molar proportion of individual VFA. For CS, acetate was increased (p = 0.02) and butyrate was decreased (p<0.01) by adding HMB and AOC. Increase of propionate was only occurred with AOC (p<0.01). Populations of protozoa (p≤0.03) and fungi (p≤0.02) of CWR were differently influenced by HMB and AOC. Percentages of F. succinogenes, R. albus, and R. flavefaciens (p<0.01) increased when AOC was added to CWR. For CS, HMB decreased the protozoa population (p = 0.01) and increased the populations of F. succinogenes and R. albus (p≤0.03). Populations of fungi, F. succinogenes (p = 0.02) and R. flavefacien (p = 0.03) were increased by adding AOC. The HMB×AOC interactions were noted in MCP, fungi and R. flavefacien for CWR and GP, ammonia-N, MCP, total VFA, propionate, acetate/propionate (A/P) and R. albus for CS. It is inferred that addition of HMB and AOC could influence rumen fermentation of forages by increasing the number of rumen microbes.

  10. 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.

  11. Responses of microbial community and acidogenic intermediates to different water regimes in a hybrid solid anaerobic digestion system treating food waste.

    PubMed

    Xu, Suyun; Selvam, Ammaiyappan; Karthikeyan, Obuli P; Wong, Jonathan W C

    2014-09-01

    This study investigated the effects of different water regimes in an acidogenic leach bed reactor (LBR) during 16-day batch mode food waste digestion. LBRs were operated under five water replacement ratios (WRRs) (100%, 75%, 50%, 25% and 5% in LBRs R1, R2, R3, R4 and R5, respectively) and methanogenic effluent (ME) addition with two leachate recirculation frequencies (once in 24 h and 12 h in LBRs R6 and R7, respectively). Results showed that 50-100% WRRs accelerated the hydrolysis and acidogenesis with butyrate as the dominant product (∼35% of COD); whereas 5-25% WRRs promoted propionate production. The ME recirculation enhanced protein decomposition and reduced ethanol production. Lactobacillus dominated in LBRs with water addition (R1-R5), while Clostridium and hetero-fermenting lactic acid bacteria dominated in LBR with ME addition (R7). The highest volatile solid degradation (82.9%) and methane yield (0.29 L-CH4/g VS) were obtained with ME addition at 0.7 d hydraulic retention time. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Effects of replacing dietary starch with neutral detergent-soluble fibre on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria using the rumen simulation technique (RUSITEC).

    PubMed

    Zhao, X H; Liu, C J; Liu, Y; Li, C Y; Yao, J H

    2013-12-01

    A rumen simulation technique (RUSITEC) apparatus with eight 800 ml fermenters was used to investigate the effects of replacing dietary starch with neutral detergent-soluble fibre (NDSF) by inclusion of sugar beet pulp in diets on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria. Experimental diets contained 12.7, 16.4, 20.1 or 23.8% NDSF substituted for starch on a dry matter basis. The experiment was conducted over two independent 15-day incubation periods with the last 8 days used for data collection. There was a tendency that 16.4% NDSF in the diet increased the apparent disappearance of organic matter (OM) and neutral detergent fibre (NDF). Increasing dietary NDSF level increased carboxymethylcellulase and xylanase activity in the solid fraction and apparent disappearance of acid detergent fibre (ADF) but reduced the 16S rDNA copy numbers of Ruminococcus albus in both liquid and solid fractions and R. flavefaciens in the solid fraction. The apparent disappearance of dietary nitrogen (N) was reduced by 29.6% with increased dietary NDSF. Substituting NDSF for starch appeared to increase the ratios of acetate/propionate and methane/volatile fatty acids (VFA) (mol/mol). Replacing dietary starch with NDSF reduced the daily production of ammonia-N and increased the growth of the solid-associated microbial pellets (SAM). Total microbial N flow and efficiency of microbial synthesis (EMS), expressed as g microbial N/kg OM fermented, tended to increase with increased dietary NDSF, but the numerical increase did not continue as dietary NDSF exceeded 20.1% of diet DM. Results suggested that substituting NDSF for starch up to 16.4% of diet DM increased digestion of nutrients (except for N) and microbial synthesis, and further increases (from 16.4% to 23.8%) in dietary NDSF did not repress microbial synthesis but did significantly reduce digestion of dietary N. © 2012 Blackwell Verlag GmbH.

  13. Optimization of odd chain fatty acid production by Yarrowia lipolytica.

    PubMed

    Park, Young-Kyoung; Dulermo, Thierry; Ledesma-Amaro, Rodrigo; Nicaud, Jean-Marc

    2018-01-01

    Odd chain fatty acids (odd FAs) have a wide range of applications in therapeutic and nutritional industries, as well as in chemical industries including biofuel. Yarrowia lipolytica is an oleaginous yeast considered a preferred microorganism for the production of lipid-derived biofuels and chemicals. However, it naturally produces negligible amounts of odd chain fatty acids. The possibility of producing odd FAs using Y. lipolytica was investigated. Y. lipolytica wild-type strain was shown able to grow on weak acids; acetate, lactate, and propionate. Maximal growth rate on propionate reached 0.24 ± 0.01 h -1 at 2 g/L, and growth inhibition occurred at concentration above 10 g/L. Wild-type strain accumulated lipids ranging from 7.39 to 8.14% (w/w DCW) depending on the carbon source composition, and odd FAs represented only 0.01-0.12 g/L. We here proved that the deletion of the PHD1 gene improved odd FAs production, which reached a ratio of 46.82% to total lipids. When this modification was transferred to an obese strain, engineered for improving lipid accumulation, further increase odd FAs production reaching a total of 0.57 g/L was shown. Finally, a fed-batch co-feeding strategy was optimized for further increase odd FAs production, which generated 0.75 g/L, the best production described so far in Y. lipolytica . A Y. lipolytica strain able to accumulate high level of odd chain fatty acids, mainly heptadecenoic acid, has been successfully developed. In addition, a fed-batch co-feeding strategy was optimized to further improve lipid accumulation and odd chain fatty acid content. These lipids enriched in odd chain fatty acid can (1) improve the properties of the biodiesel generated from Y. lipolytica lipids and (2) be used as renewable source of odd chain fatty acid for industrial applications. This work paves the way for further improvements in odd chain fatty acids and fatty acid-derived compound production.

  14. The effect of lactic acid bacteria on cocoa bean fermentation.

    PubMed

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2015-07-16

    Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. Yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. However, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully understood. Using controlled laboratory fermentations, this study investigated the contribution of lactic acid bacteria to cocoa bean fermentation. Cocoa beans were fermented under conditions where the growth of lactic acid bacteria was restricted by the use of nisin and lysozyme. The resultant microbial ecology, chemistry and chocolate quality of beans from these fermentations were compared with those of indigenous (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae, the lactic acid bacteria Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in control fermentations. In fermentations with the presence of nisin and lysozyme, the same species of yeasts and acetic acid bacteria grew but the growth of lactic acid bacteria was prevented or restricted. These beans underwent characteristic alcoholic fermentation where the utilization of sugars and the production of ethanol, organic acids and volatile compounds in the bean pulp and nibs were similar for beans fermented in the presence of lactic acid bacteria. Lactic acid was produced during both fermentations but more so when lactic acid bacteria grew. Beans fermented in the presence or absence of lactic acid bacteria were fully fermented, had similar shell weights and gave acceptable chocolates with no differences in sensory rankings. It was concluded that lactic acid bacteria may not be necessary for successful cocoa fermentation. Copyright © 2015. Published by Elsevier B.V.

  15. Longicalycinin A, a new cytotoxic cyclic peptide from Dianthus superbus var. longicalycinus (MAXIM.) WILL.

    PubMed

    Hsieh, Pei-Wen; Chang, Fang-Rong; Wu, Ching-Chung; Li, Chien-Ming; Wu, Kuen-Yuh; Chen, Su-Li; Yen, Hsin-Fu; Wu, Yang-Chang

    2005-03-01

    A new cyclic peptide, longicalycinin A (1), and six known compounds, vaccaroside A, dianoside A, dianoside G, 3-(4-hydroxy-3-methoxy-phenyl)propionic acid methyl ester, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde were isolated from the MeOH extract of Dianthus superbus var. longicalycinus. The amino acid sequences of 1 was elucidated as cyclo(Gly(1)-Phe(2)-Tyr(3)-Pro(4)-Phe(5)-) on the basis of ESI tandem mass fragmentation analysis, chemical evidence, and extensive 2D NMR methods. Furthermore, compound 1 showed cytotoxicity to Hep G2 cancer cell line.

  16. Nicotinic Acid Metabolism, V. A Cobamide Coenzyme-Dependent Conversion of α-Methyleneglutaric Acid to Dimethylmaleic Acid

    PubMed Central

    Kung, H. F.; Cederbaum, S.; Tsai, L.; Stadtman, T. C.

    1970-01-01

    A new B12-coenzyme-dependent isomerization, catalyzed by extracts of a nicotinate-fermenting clostridium, results in the conversion of α-methyleneglutaric acid to dimethylmaleic acid. These two acids are intermediates in the multistep anaerobic process wherein nicotinate is converted, ultimately, to one mole each of propionate, acetate, carbon dioxide, and ammonia. Dimethylmaleic acid reacts in its anhydride form with 2,4-dinitrophenylhydrazine to form N-2′,4′-dinitrophenyl-anilino-3,4-dimethylmaleimide. The characteristic reddish color exhibited by the latter derivative in alkaline solution serves as a convenient quantitative assay for dimethylmaleic acid. Comparison of the 2,4-dinitrophenylhydrazine derivatives of the product of the enzymic reaction and of synthetic dimethylmaleic anhydride showed them to be identical in every respect. PMID:5266166

  17. Contribution of propionate to glucose synthesis in sheep

    PubMed Central

    Leng, R. A.; Steel, J. W.; Luick, J. R.

    1967-01-01

    1. The production rate of propionate in the rumen and the entry rate of glucose into the body pool of glucose in sheep were measured by isotope-dilution methods. Propionate production rates were measured by using a continuous infusion of specifically labelled [14C]propionate. Glucose entry rates were estimated by using either a primed infusion or a continuous infusion of [U-14C]glucose. 2. The specific radioactivity of plasma glucose was constant between 4 and 9hr. after the commencement of intravenous infusion of [U-14C]glucose and between 1 and 3hr. when a primed infusion was used. 3. Infusion of [14C]propionate intraruminally resulted in a fairly constant specific radioactivity of rumen propionate between about 4 and 9hr. and of plasma glucose between 6 and 9hr. after the commencement of the infusion. Comparison of the mean specific radioactivities of glucose and propionate during these periods allowed estimates to be made of the contribution of propionate to glucose synthesis. 4. Comparisons of the specific radioactivities of plasma glucose and rumen propionate during intraruminal infusions of one of [1-14C]-, [2-14C]-, [3-14C]- and [U-14C]-propionate indicated considerable exchange of C-1 of propionate on conversion into glucose. The incorporation of C-2 and C-3 of propionate into glucose and lactate indicated that 54% of both the glucose and lactate synthesized arose from propionate carbon. 5. No differences were found for glucose entry rates measured either by a primed infusion or by a continuous infusion. The mean entry rate (±s.e.m.) of glucose estimated by using a continuous infusion into sheep was 0·33±0·03 (4) m-mole/min. and by using a primed infusion was 0·32±0·01 (4) m-mole/min. The mean propionate production rate was 1·24±0·03 (8) m-moles/min. The conversion of propionate into glucose was 0·36 m-mole/min., indicating that 32% of the propionate produced in the rumen is used for glucose synthesis. 6. It was indicated that a considerable amount of the propionate converted into glucose was first converted into lactate. PMID:4860545

  18. Survival and reproduction of some nematodes as affected by muck and organic acids.

    PubMed

    Elmiligy, I A; Norton, D C

    1973-01-01

    Fulvic, humic, acetic, N-bulyric, formic, lactic, and propionic acids were inhibitory to the survival or reproduction of Aphelenchus avenae, Aphelenchoides goodeyi, Helicotylenchus pseudorobustus, Meloidogyne hapla or Xiphinema americanum. Reproduction of H. pseudorobustus and M. hapla significantly increased with increasing amounts of muck added to sand, and with the initial amount of nematode inoculum. All acids except humic and fulvic were lethal, in vitro, to all nematode species tested. When A. goodeyi was treated with fulvic acid, reproduction was reduced significantly when compared with sodium humate or water treatments. Treatment of H. pseudorobustus with fulvic acid (pH 3.5) resulted in a greater reduction in reproduction in soil than did treatment with humic acid (pH 3.5).

  19. In vitro determination of the mechanical and chemical properties of a fibre orthodontic retainer.

    PubMed

    Silvestrini-Biavati, Armando; Angiero, Francesca; Gibelli, Francesca; Signore, Antonio; Benedicenti, Stefano

    2012-12-01

    The aim of this study was to analyse, in vitro, the chemical and mechanical properties of a new fibre retainer, Everstick, comparing its characteristics with the requirements for an orthodontic retainer. Chemical analysis was used to examine seven fibre bundles exposed to a photocuring lamp and then to different acids and resistance to corrosion by artificial saliva fortified with plaque acids. The mechanical properties examined were tensile strength and resistance to flexural force. Ten fibre samples were tested for each mechanical analysis and the mean value and standard deviation were calculated. Wilcoxon signed rank test was used to evaluate change in weight after treatment in each group. To determine changes over time between the groups for each acid considered separately, both repeated measures analysis of variance (ANOVA) on original data and on rank transformed data were used. If the results were different, ANOVA on rank-transformed data was considered. Acetic acid was found to be the most corrosive and caused the most substance loss: both pure and at the salivary pH value. Hydrofluoric acid was the most damaging. For all acids analysed in both groups (lactic, formic, acetic, propionic), changes after treatment were statistically different between two groups (P < 0.001 for lactic, acetic, propionic; P = 0.004 for formic acid).The mean Young's modulus value was 68 510 MPa. Deformation before the fibre separated into its constituent elements (glass fibre and composite) was 3.9 per cent, stress to rupture was 1546 MPa, and resistance to bending was 534 MPa. The deflection produced over a length of 12 mm was 1.4 mm. The fibre bundle was attacked by acids potentially present in the oral cavity; the degree of aggressiveness depending on the acid concentration. To preserve fibre bundles long term, careful plaque control is necessary, especially in the interproximal spaces, to avoid acid formation. The tested product was found to be sufficiently strong to oppose flexural and occlusal forces.

  20. Enzyme effects on extruded diets for dogs with soybean meal as a substitute for poultry by-product meal.

    PubMed

    Tortola, L; Souza, N G; Zaine, L; Gomes, M O S; Matheus, L F O; Vasconcellos, R S; Pereira, G T; Carciofi, A C

    2013-05-01

    The effects of exogenous enzymes supplementation on kibble diets for dogs formulated with soybean meal (SBM) as a substitute for poultry by-product meal (PM) was investigated on nutrient digestibility, fermentation products formation, post-prandial urea response and selected faecal bacteria counts. Two kibble diets with similar compositions were used in two trials: PM-based diet (28.9% of PM; soybean hulls as a fibre source) and SBM-based diet (29.9% of SBM). In experiment 1, the SBM diet was divided into three diets: SBM-0, without enzyme addition; SBM-1, covered after extrusion with 7500 U protease/kg and 45 U cellulase/kg; and SBM-2, covered with 15,000 U protease/kg and 90 U cellulase/kg. In experiment 2, the SBM diet was divided into three diets: SBM-0; SBM-1, covered with 140 U protease/kg; 8 U cellulase/kg, 800 U pectinase/kg, 60 U phytase/kg, 40 U betaglucanase/kg and 20 U xylanase/kg; and SMB-2, covered with 700 U protease/kg, 40 U cellulase/kg, 4000 U pectinase/kg, 300 U phytase/kg, 200 U betaglucanase/kg and 100 U xylanase/kg. Each experiment followed a block design with six dogs per diet. Data were submitted to analysis of variance and means compared by orthogonal and polynomial contrasts (p < 0.05). In both experiments, nutrients and energy digestibility did not differ between diets (p > 0.05). SBM consumption resulted in increased faecal moisture and production (p < 0.05), without effect on faecal score. Higher concentration of propionate, acetate and lactate, and lower ammonia and pH were found in the faeces of dogs fed SBM (p < 0.05). Higher post-prandial urea was verified in dogs fed SBM (p < 0.05). In experiment 2, the addition of enzymes increased faecal concentration of propionate, acetate and total short-chain fatty acid (p < 0.05) and tended to reduce post-prandial urea concentration (p = 0.06). Although with similar digestibility, SBM shows a worse utilization of absorbed amino acids than the PM. Soybean oligosaccharides can beneficially change gut fermentation product formation. Enzymes can increase the gut fermentation activity and improve the SBM proteic value. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

  1. Structural implications of the C-terminal tail in the catalytic and stability properties of manganese peroxidases from ligninolytic fungi

    DOE PAGES

    Fernández-Fueyo, Elena; Acebes, Sandra; Ruiz-Dueñas, Francisco J.; ...

    2014-11-22

    The genome ofCeriporiopsis subvermisporaincludes 13 manganese peroxidase (MnP) genes representative of the three subfamilies described in ligninolytic fungi, which share an Mn 2+-oxidation site and have varying lengths of the C-terminal tail. We expressed short, long and extralong MnPs heterologously and biochemically characterized, and the first structure of an extralong MnP was solved. Its C-terminal tail surrounds the haem-propionate access channel, contributing to Mn 2+oxidation by the internal propionate, but prevents the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), which is only oxidized by short MnPs and by shortened-tail variants from site-directed mutagenesis. Furthermore, the tail, which is anchored by numerous contacts, notmore » only affects the catalytic properties of long/extralong MnPs but is also associated with their high acidic stability. Cd 2+binds at the Mn 2+-oxidation site and competitively inhibits oxidation of both Mn 2+and ABTS. Moreover, mutations blocking the haem-propionate channel prevent substrate oxidation. This agrees with molecular simulations that position ABTS at an electron-transfer distance from the haem propionates of anin silicoshortened-tail form, while it cannot reach this position in the extralong MnP crystal structure. Small differences exist between the long and the extralong MnPs, which do not justify their classification as two different subfamilies, but they significantly differ from the short MnPs, with the presence/absence of the C-terminal tail extension being implicated in these differences.« less

  2. Impact of Novel Prebiotic Galacto-Oligosaccharides on Various Biomarkers of Colorectal Cancer in Wister Rats.

    PubMed

    Qamar, Tahir Rasool; Iqbal, Sanaullah; Syed, Fatima; Nasir, Muhammad; Rehman, Habib; Iqbal, Muhammad Aamir; Liu, Rui Hai

    2017-08-31

    Colorectal cancer (CRC) is one of the leading causes of cancer deaths around the globe. Bioactive food ingredients such as prebiotics have protective potential in colon cancer. Data on galacto-oligosaccharides (GalOS) against CRC are very limited and GalOS used in this study have β-1,6 and β-1,3 as major glycosidic linkages and, to our best knowledge, were never used before against any cancer treatment. This study aims to investigate the protective role of novel GalOS against various biomarkers of CRC including aberrant crypt foci (ACF), bacterial enzymes and short chain fatty acids (SCFA) in a rodent model induced with 1,2-dimethylhydrazine dihydrochloride (DMH). Inulin group was taken as positive control in present study to compare novel GalOS protective effects. GalOS doses of 76-151 mg and inulin doses of 114 mg were given to different groups treated with DMH. Results showed that ACF formation was significantly ( p ≤ 0.05) less in high dose GalOS group (27.3%). GalOS also had protective effects against DMH-induced body weight loss and showed higher level of cecal and fecal SCFA (acetate, propionate and butyrate). High doses of GalOS also resulted in significant ( p ≤ 0.05) reduction of bacterial enzymatic activities. Increased populations of beneficial bacteria (bifidobacteria and lactobacilli) and decreased concentrations of harmful bacteria were observed in all prebiotics treatment groups. It can be concluded that novel GalOS exhibit robust protective activity against ACF formation in vivo.

  3. 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...

  4. Short communication: Effects of diets containing supplemental fats on ruminal fermentation and milk odd- and branched-chain fatty acids in dairy cows.

    PubMed

    Vazirigohar, M; Dehghan-Banadaky, M; Rezayazdi, K; Nejati-Javaremi, A; Mirzaei-Alamouti, H; Patra, A K

    2018-07-01

    There is a growing interest in odd- and branched-chain fatty acids (OBCFA) in milk following reports that several branched-chain fatty acids (FA) have health promoting effects, and certain milk OBCFA could serve as a biomarker to assess ruminal function. Twenty-four Holstein cows were fed 3 low-forage diets containing 30 g/kg of dry matter of prilled palm fat (PPF), sunflower oil (SO), or an equal mixture of both fats (experiment 1) or 3 diets containing 30 g/kg of dry matter of SO with a forage-to-concentrate ratio of 39:61, 44:56, or 48:52 (Experiment 2); diets were fed to investigate milk OBCFA composition and to explore the relationships between ruminal VFA and milk OBCFA using principal component analysis. Including SO in diets decreased yields of milk 13:0 anteiso, 15:0 anteiso, 15:0, 17:0, cis-9 15:1, and cis-9 17:1 compared with PPF. The molar proportion of ruminal propionate was the lowest and the yields of milk 14:0 iso and 16:0 iso were the greatest with the diet containing both fat supplements. Replacing concentrate with forages linearly increased ruminal acetate and yields of milk 13:0 iso, 14:0 iso, 15:0 iso, 16:0 iso, 17:0 iso, 13:0 anteiso, 15:0 anteiso, 15:0, 17:0, cis-9 15:1, and cis-9 17:1. The principal component analysis revealed that ruminal molar proportion of acetate related to concentrations of milk iso FA containing <17-carbon, whereas ruminal propionate related to milk 15:0, 17:0, cis-9 15:1, and cis-9 17:1, with the stronger correlations between milk OBCFA and ruminal acetate than propionate. No associations were found between ruminal molar proportion of butyrate and milk OBCFA concentrations. The results suggest that complete replacement of PPF with SO at 30 g/kg of dry matter in low-forage diets is not an effective strategy to enhance bioactive branched-chain FA in milk, rather this feeding practice lowers anteiso FA in milk; however, increasing forage proportion in diets containing SO enhances several iso and anteiso FA in milk. The milk OBCFA concentrations have stronger correlations with ruminal acetate molar proportion than with propionate or butyrate in cows fed diets containing supplemental fats. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Effects of two whole-grain barley varieties on caecal SCFA, gut microbiota and plasma inflammatory markers in rats consuming low- and high-fat diets.

    PubMed

    Zhong, Yadong; Marungruang, Nittaya; Fåk, Frida; Nyman, Margareta

    2015-05-28

    Mixed-linkage β-glucans are fermented by the colon microbiota that give rise to SCFA. Propionic and butyric acids have been found to play an important role in colonic health, as well as they may have extraintestinal metabolic effects. The aim of the present study was to investigate how two whole-grain barley varieties differing in dietary fibre and β-glucan content affected caecal SCFA, gut microbiota and some plasma inflammatory markers in rats consuming low-fat (LF) or high-fat (HF) diets. Barley increased the caecal pool of SCFA in rats fed the LF and HF diets compared with those fed the control diet, and the effect was generally dependent on fibre content, an exception was butyric acid in the LF setting. Furthermore, whole-grain barley reduced plasma lipopolysaccharide-binding protein and monocyte chemoattractant protein-1, increased the caecal abundance of Lactobacillus and decreased the Bacteroides fragilis group, but increased the number of Bifidobacterium only when dietary fat was consumed at a low level. Fat content influenced the effects of barley: rats fed the HF diets had a higher caecal pool of acetic and propionic acids, higher concentrations of amino acids and higher amounts of lipids in the portal plasma and liver than rats fed the LF diets; however, less amounts of butyric acid were generally formed. Interestingly, there was an increase in the caecal abundance of Akkermansia and the caecal pool of succinic acid, and a decrease in the proportion of Bifidobacterium and the Clostridium leptum group. In summary, whole-grain barley decreased HF diet-induced inflammation, which was possibly related to the formation of SCFA and changes in microbiota composition. High β-glucan content in the diet was associated with reduced plasma cholesterol levels.

  6. A novel LCMSMS method for quantitative measurement of short-chain fatty acids in human stool derivatized with 12C- and 13C-labelled aniline.

    PubMed

    Chan, James Chun Yip; Kioh, Dorinda Yan Qin; Yap, Gaik Chin; Lee, Bee Wah; Chan, Eric Chun Yong

    2017-05-10

    A novel liquid chromatography tandem mass spectrometry (LCMSMS) method for the quantitative measurement of gut microbial-derived short-chain fatty acids (SCFAs) in human infant stool has been developed and validated. Baseline chromatographic resolution was achieved for 12 SCFAs (acetic, butyric, caproic, 2,2-dimethylbutyric, 2-ethylbutyric, isobutyric, isovaleric, 2-methylbutyric, 4-methylvaleric, propionic, pivalic and valeric acids) within an analysis time of 15min. A novel sequential derivatization of endogenous and spiked SCFAs in stool via 12 C- and 13 C-aniline respectively, facilitated the accurate quantitation of 12 C-aniline derivatized endogenous SCFAs based on calibration of exogenously 13 C-derivatized SCFAs. Optimized quenching of derivatization agents prior to LCMSMS analysis further reduced to negligible levels the confounding chromatographic peak due to in-line derivatization of unquenched aniline with residual acetic acid present within the LCMS system. The effect of residual acetic acid, a common LCMS modifier, in analysis of SCFAs has not been addressed in previous SCFA assays. For the first time, a total of 9 SCFAs (acetic, butyric, caproic, isobutyric, isovaleric, 2-methylbutyric, 4-methylvaleric, propionic and valeric acids) were detected and quantitated in 107 healthy infant stool samples. The abundance and diversity of SCFAs in infant stool vary temporally from 3 weeks onwards and stabilize towards the end of 12 months. This in turn reflects the maturation of infant SCFA-producing gut microbiota community. In summary, this novel method is applicable to future studies that investigate the biological roles of SCFAs in paediatric health and diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Fermentation properties of isomaltooligosaccharides are affected by human fecal enterotypes.

    PubMed

    Wu, Qinqin; Pi, Xiong'e; Liu, Wei; Chen, Huahai; Yin, Yeshi; Yu, Hongwei D; Wang, Xin; Zhu, Liying

    2017-12-01

    Isomaltooligosaccharides (IMOs) are enzymatically synthesized oligosaccharides that have potential prebiotic effects. Five IMO substrates with 2-16° of polymerization (DP) were studied for their fermentation capacities using human microbiomes in an in vitro batch fermentation model. Eleven fecal slurries belonging to three enterotypes, including the Bacteroides-, Prevotella- and Mixed-type, exhibited different degradation rates for long chain IMOs (DP 7 to 16). In contrast, the degradation rates for short chain IMOs (DP 2 to 6) were not affected by enterotypes. Both 16S rRNA gene sequencing and quantitative PCR demonstrated that, after fermentation, the Bifidobacterium growth with IMOs was primarily detected in the Bacteroides- and Mixed-type (non-Prevotella-type), and to a lesser degree in the Prevotella-type. Interestingly, the Prevotella-type microbiome had higher levels of propionic acid and butyric acid production than non-Prevotella-type microbiome after IMOs fermentation. Moreover, principal coordinate analysis (PCoA) of both denaturing gradient gel electrophoresis (DGGE) profiling and 16S rRNA sequencing data demonstrated that the microbiome community compositions were separately clustered based on IMO chain length, suggesting significant impact of DP on the bacterial community structure. The current results clearly demonstrated that the IMO chain length could modulate the structure and composition of the human colonic microbiome. Different responses to short and long chain IMOs were observed from three human enterotypes, indicating that IMOs may be used as therapeutic substrates for directly altering human colonic bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Effect of prebiotics on the fecal microbiota of elderly volunteers after dietary supplementation of Bacillus coagulans GBI-30, 6086.

    PubMed

    Nyangale, Edna P; Farmer, Sean; Keller, David; Chernoff, David; Gibson, Glenn R

    2014-12-01

    In advancing age, gut populations of beneficial microbes, notably Bifidobacterium spp., show a marked decline. This contributes to an environment less capable of maintaining homoeostasis. This in vitro investigation studied the possible synergistic effects of probiotic supplementation in modulating the gut microbiota enabling prebiotic therapy to in elderly persons. Single stage batch culture anaerobic fermenters were used and inoculated with fecal microbiota obtained from volunteers after taking a 28 day treatment of Bacillus coagulans GBI-30, 6086 (GanedenBC30 (BC30)) or a placebo. The response to prebiotic supplements fructooligosaccharides (FOS) and galactooligosaccharides (GOS) in the fermenters was assessed. Bacterial enumeration was carried out using fluorescent in situ hybridisation and organic acids measured by gas chromatography. Baseline populations of Faecalibacterium prausnitzii, Clostridium lituseburense and Bacillus spp. were significantly higher in those having consumed BC30 compared to the placebo. Both prebiotics increased populations of several purportedly beneficial bacterial groups in both sets of volunteers. Samples from volunteers having ingested the BC30 also increased populations of C. lituseburense, Eubacterium rectale and F. prausnitzii more so than in persons who had consumed the placebo, this also resulted in significantly higher concentrations of butyrate, acetate and propionate. This shows that consumption of BC30 and subsequent use of prebiotics resulted in elevated populations of beneficial genres of bacteria as well as organic acid production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Effects of cinnamaldehyde and garlic oil on rumen microbial fermentation in a dual flow continuous culture.

    PubMed

    Busquet, M; Calsamiglia, S; Ferret, A; Cardozo, P W; Kamel, C

    2005-07-01

    Eight continuous culture fermentors inoculated with ruminal liquor from heifers fed a 50:50 alfalfa hay:concentrate diet (17.6% crude protein, 28.0% neutral detergent fiber) were used in 3 replicated periods to study the effects of cinnamaldehyde (CIN) and garlic oil (GAR) on rumen microbial fermentation. Treatments were no additive (negative control); 1.25 mg/L (MON) and 12.5 mg/L (MON10) of the ionophore antibiotic monensin (positive control); 31.2 mg/L CIN (CIN) and 312 mg/L (CIN10) of CIN; and 31.2 mg/L GAR (GAR) and 312 mg/L (GAR10) of GAR (Allium sativa). The MON10 caused expected changes in microbial fermentation patterns (a decrease in fiber digestion, ammonia N concentration, and proportions of acetate and butyrate; an increase in the proportion of propionate; and a trend to increase small peptide plus AA N concentration). The CIN decreased the proportion of acetate and branch-chained volatile fatty acids (VFA) and increased the proportion of propionate; CIN10 decreased the proportion of acetate and increased the proportion of butyrate compared with the control. The GAR10 increased the proportion of propionate and butyrate and decreased the proportion of acetate and branch-chained VFA compared with the control. The GAR10 also increased the small peptide plus amino acid N concentration, although no effects were observed on large peptides or ammonia N concentrations. The CIN and GAR10 resulted in similar effects as monensin, with the exception of the effects on the molar proportion of butyrate, which suggests that they might have a different mode of action in affecting in vitro microbial fermentation.

  10. Purification and Characterization of Novel Antifungal Compounds from the Sourdough Lactobacillus plantarum Strain 21B

    PubMed Central

    Lavermicocca, Paola; Valerio, Francesca; Evidente, Antonio; Lazzaroni, Silvia; Corsetti, Aldo; Gobbetti, Marco

    2000-01-01

    Sourdough lactic acid bacteria were selected for antifungal activity by a conidial germination assay. The 10-fold-concentrated culture filtrate of Lactobacillus plantarum 21B grown in wheat flour hydrolysate almost completely inhibited Eurotium repens IBT18000, Eurotium rubrum FTDC3228, Penicillium corylophilum IBT6978, Penicillium roqueforti IBT18687, Penicillium expansum IDM/FS2, Endomyces fibuliger IBT605 and IDM3812, Aspergillus niger FTDC3227 and IDM1, Aspergillus flavus FTDC3226, Monilia sitophila IDM/FS5, and Fusarium graminearum IDM623. The nonconcentrated culture filtrate of L. plantarum 21B grown in whole wheat flour hydrolysate had similar inhibitory activity. The activity was fungicidal. Calcium propionate at 3 mg ml−1 was not effective under the same assay conditions, while sodium benzoate caused inhibition similar to L. plantarum 21B. After extraction with ethyl acetate, preparative silica gel thin-layer chromatography, and chromatographic and spectroscopic analyses, novel antifungal compounds such as phenyllactic and 4-hydroxy-phenyllactic acids were identified in the culture filtrate of L. plantarum 21B. Phenyllactic acid was contained at the highest concentration in the bacterial culture filtrate and had the highest activity. It inhibited all the fungi tested at a concentration of 50 mg ml−1 except for P. roqueforti IBT18687 and P. corylophilum IBT6978 (inhibitory concentration, 166 mg ml−1). L. plantarum 20B, which showed high antimold activity, was also selected. Preliminary studies showed that phenyllactic and 4-hydroxy-phenyllactic acids were also contained in the bacterial culture filtrate of strain 20B. Growth of A. niger FTDC3227 occurred after 2 days in breads started with Saccharomyces cerevisiae 141 alone or with S. cerevisiae and Lactobacillus brevis 1D, an unselected but acidifying lactic acid bacterium, while the onset of fungal growth was delayed for 7 days in bread started with S. cerevisiae and selected L. plantarum 21B. PMID:10966432

  11. Purification and characterization of novel antifungal compounds from the sourdough Lactobacillus plantarum strain 21B.

    PubMed

    Lavermicocca, P; Valerio, F; Evidente, A; Lazzaroni, S; Corsetti, A; Gobbetti, M

    2000-09-01

    Sourdough lactic acid bacteria were selected for antifungal activity by a conidial germination assay. The 10-fold-concentrated culture filtrate of Lactobacillus plantarum 21B grown in wheat flour hydrolysate almost completely inhibited Eurotium repens IBT18000, Eurotium rubrum FTDC3228, Penicillium corylophilum IBT6978, Penicillium roqueforti IBT18687, Penicillium expansum IDM/FS2, Endomyces fibuliger IBT605 and IDM3812, Aspergillus niger FTDC3227 and IDM1, Aspergillus flavus FTDC3226, Monilia sitophila IDM/FS5, and Fusarium graminearum IDM623. The nonconcentrated culture filtrate of L. plantarum 21B grown in whole wheat flour hydrolysate had similar inhibitory activity. The activity was fungicidal. Calcium propionate at 3 mg ml(-1) was not effective under the same assay conditions, while sodium benzoate caused inhibition similar to L. plantarum 21B. After extraction with ethyl acetate, preparative silica gel thin-layer chromatography, and chromatographic and spectroscopic analyses, novel antifungal compounds such as phenyllactic and 4-hydroxy-phenyllactic acids were identified in the culture filtrate of L. plantarum 21B. Phenyllactic acid was contained at the highest concentration in the bacterial culture filtrate and had the highest activity. It inhibited all the fungi tested at a concentration of 50 mg ml(-1) except for P. roqueforti IBT18687 and P. corylophilum IBT6978 (inhibitory concentration, 166 mg ml(-1)). L. plantarum 20B, which showed high antimold activity, was also selected. Preliminary studies showed that phenyllactic and 4-hydroxy-phenyllactic acids were also contained in the bacterial culture filtrate of strain 20B. Growth of A. niger FTDC3227 occurred after 2 days in breads started with Saccharomyces cerevisiae 141 alone or with S. cerevisiae and Lactobacillus brevis 1D, an unselected but acidifying lactic acid bacterium, while the onset of fungal growth was delayed for 7 days in bread started with S. cerevisiae and selected L. plantarum 21B.

  12. A mathematical model for the interactive behavior of sulfate-reducing bacteria and methanogens during anaerobic digestion.

    PubMed

    Ahammad, S Ziauddin; Gomes, James; Sreekrishnan, T R

    2011-09-01

    Anaerobic degradation of waste involves different classes of microorganisms, and there are different types of interactions among them for substrates, terminal electron acceptors, and so on. A mathematical model is developed based on the mass balance of different substrates, products, and microbes present in the system to study the interaction between methanogens and sulfate-reducing bacteria (SRB). The performance of major microbial consortia present in the system, such as propionate-utilizing acetogens, butyrate-utilizing acetogens, acetoclastic methanogens, hydrogen-utilizing methanogens, and SRB were considered and analyzed in the model. Different substrates consumed and products formed during the process also were considered in the model. The experimental observations and model predictions showed very good prediction capabilities of the model. Model prediction was validated statistically. It was observed that the model-predicted values matched the experimental data very closely, with an average error of 3.9%.

  13. Evaluation of Adsorption Characteristics of a Fibrous Adsorbent Containing Zwitter-Ionic Functional Group, Targeting Organic Acids.

    PubMed

    Nakazawa, Akira; Tang, Ning; Inoue, Yoshinori; Kamichatani, Waka; Katoh, Toshifumi; Saito, Mitsuru; Obara, Kenji; Toriba, Akira; Hayakawa, Kazuichi

    2017-01-01

    Diallylamine-maleic acid copolymer (DAM)-nonwoven fabric (DAM-f), a fibrous adsorbent, contains DAM with zwitter-ionic functional groups and forms a hydration layer on the surface. The aim of this report was to evaluate the adsorption selectivity of DAM-f to semi-volatile organic acid (C1-C5). In the aqueous phase, formic acid dissolved in the hydration layer bound to the imino group of DAM-f due to anion exchange interaction. In the gas phase, the adsorption amounts of organic acids increased with the exposure time. Moreover, the adsorption rate constants correlated with the air/water partition coefficients (log K aw ) for formic acid, propionic acid, butyric acid, valeric acid and isovaleric acid, except for acetic acid. These results indicate that DAM-f is highly selective to hydrophilic compounds which easily move from the air to the hydration layer of DAM-f.

  14. Ruminal and intermediary metabolism of propylene glycol in lactating Holstein cows.

    PubMed

    Kristensen, N B; Raun, B M L

    2007-10-01

    Four lactating Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the mesenteric artery, mesenteric vein, hepatic portal vein, and hepatic vein were used in a cross-over design to study the metabolism of propylene glycol (PG). Each cow received 2 treatments: control (no infusion) and infusion of 650 g of PG into the rumen at the time of the morning feeding. Propylene glycol was infused on the day of sampling only. Samples of arterial, portal, and hepatic blood as well as ruminal fluid were obtained at 0.5 h before feeding and at 0.5, 1.5, 2.5, 3.5, 5, 7, 9, and 11 h after feeding. Infusion of PG did not affect ruminal pH or the total concentration of ruminal volatile fatty acids, but did decrease the molar proportion of ruminal acetate. The ruminal concentrations of PG, propanol, and propanal as well as the molar proportion of propionate increased with PG infusion. The plasma concentrations of PG, ethanol, propanol, propanal, glucose, L-lactate, propionate, and insulin increased with PG and the plasma concentrations of acetate and beta-hydroxybutyrate decreased. The net portal flux of PG, propanol, and propanal increased with PG. The hepatic uptake of PG was equivalent to 19% of the intraruminal dose. When cows were dosed with PG, the hepatic extraction of PG was between 0 and 10% depending on the plasma concentration of PG, explaining the slow decrease in arterial PG. The increased net hepatic flux of L-lactate with PG could account for the entire hepatic uptake of PG, which suggests that the primary hepatic pathway for PG is oxidation to l-lactate. The hepatic uptake of propanol increased with PG, but no effects of PG on the net hepatic and net splanchnic flux of glucose were observed. Despite no effect of PG on net portal flux and net hepatic flux of propionate, the net splanchnic flux of propionate increased and the data suggest that propionate produced from hepatic metabolism of propanol is partly released to the blood. The data suggest that PG affects metabolism of the cows by 2 modes of action: 1) increased supply of l-lactate and propionate to gluconeogenesis and 2) insulin resistance of peripheral tissues induced by increased concentrations of PG and propanol as well as a decreased ratio of ketogenic to glucogenic metabolites in arterial blood plasma.

  15. Synergism of Cattle and Bison Inoculum on Ruminal Fermentation and Select Bacterial Communities in an Artificial Rumen (Rusitec) Fed a Barley Straw Based Diet.

    PubMed

    Oss, Daniela B; Ribeiro, Gabriel O; Marcondes, Marcos I; Yang, WenZhu; Beauchemin, Karen A; Forster, Robert J; McAllister, Tim A

    2016-01-01

    This study evaluated the effect of increasing the proportion of bison relative to cattle inoculum on fermentation and microbial populations within an artificial rumen (Rusitec). The experiment was a completely randomized design with a factorial treatment structure (proportion cattle:bison inoculum; 0:100, 33:67, 67:33, and 100:0) replicated in two Rusitec apparatuses ( n = 8 fermenters). The experiment was 15 d with 8 d of adaptation and 7 d of sampling. Fermenters were fed a diet of 70:30 barley straw:concentrate (DM basis). True digestibility of DM was determined after 48 h of incubation from d 13 to 15, and daily ammonia (NH 3 ) and volatile fatty acid (VFA) production were measured on d 9-12. Protozoa counts were determined at d 9, 11, 13, and 15 and particle-associated bacteria (PAB) from d 13 to 15. Select bacterial populations in the PAB were measured using RT-qPCR. Fermenter was considered the experimental unit and day of sampling as a repeated measure. Increasing the proportion of bison inoculum resulted in a quadratic effect ( P < 0.05) on straw, concentrate and total true DM disappearance and on straw and total neutral detergent fiber (aNDF) disappearance, with greater disappearances observed with mixed inoculum. There were no effect of source or proportion of inoculum on ADF disappearance ( P > 0.05). Increasing bison inoculum linearly increased ( P < 0.05) concentrate aNDF disappearance, total and concentrate N disappearance as well as total daily VFA and acetate production. A positive quadratic response ( P < 0.05) was observed for daily NH 3 -N, propionate, butyrate, valerate, isovalerate and isobutyrate production, as well as the acetate:propionate ratio. Increasing the proportion of bison inoculum linearly increased ( P < 0.05) total protozoa numbers. No effects were observed on pH, total gas and methane production, microbial N synthesis, or copies of 16S rRNA associated with total bacteria, Selenomonas ruminantium or Prevotella bryantii . Increasing bison inoculum had a quadratic effect ( P < 0.05) on Fibrobacter succinogenes , and tended to linearly ( P < 0.10) increase Ruminococcus flavefaciens and decrease ( P < 0.05) Ruminococcus albus copy numbers. In conclusion, bison inoculum increased the degradation of feed protein and fiber. A mixture of cattle and bison rumen inoculum acted synergistically, increasing the DM and aNDF disappearance of barley straw.

  16. Synergism of Cattle and Bison Inoculum on Ruminal Fermentation and Select Bacterial Communities in an Artificial Rumen (Rusitec) Fed a Barley Straw Based Diet

    PubMed Central

    Oss, Daniela B.; Ribeiro, Gabriel O.; Marcondes, Marcos I.; Yang, WenZhu; Beauchemin, Karen A.; Forster, Robert J.; McAllister, Tim A.

    2016-01-01

    This study evaluated the effect of increasing the proportion of bison relative to cattle inoculum on fermentation and microbial populations within an artificial rumen (Rusitec). The experiment was a completely randomized design with a factorial treatment structure (proportion cattle:bison inoculum; 0:100, 33:67, 67:33, and 100:0) replicated in two Rusitec apparatuses (n = 8 fermenters). The experiment was 15 d with 8 d of adaptation and 7 d of sampling. Fermenters were fed a diet of 70:30 barley straw:concentrate (DM basis). True digestibility of DM was determined after 48 h of incubation from d 13 to 15, and daily ammonia (NH3) and volatile fatty acid (VFA) production were measured on d 9–12. Protozoa counts were determined at d 9, 11, 13, and 15 and particle-associated bacteria (PAB) from d 13 to 15. Select bacterial populations in the PAB were measured using RT-qPCR. Fermenter was considered the experimental unit and day of sampling as a repeated measure. Increasing the proportion of bison inoculum resulted in a quadratic effect (P < 0.05) on straw, concentrate and total true DM disappearance and on straw and total neutral detergent fiber (aNDF) disappearance, with greater disappearances observed with mixed inoculum. There were no effect of source or proportion of inoculum on ADF disappearance (P > 0.05). Increasing bison inoculum linearly increased (P < 0.05) concentrate aNDF disappearance, total and concentrate N disappearance as well as total daily VFA and acetate production. A positive quadratic response (P < 0.05) was observed for daily NH3-N, propionate, butyrate, valerate, isovalerate and isobutyrate production, as well as the acetate:propionate ratio. Increasing the proportion of bison inoculum linearly increased (P < 0.05) total protozoa numbers. No effects were observed on pH, total gas and methane production, microbial N synthesis, or copies of 16S rRNA associated with total bacteria, Selenomonas ruminantium or Prevotella bryantii. Increasing bison inoculum had a quadratic effect (P < 0.05) on Fibrobacter succinogenes, and tended to linearly (P < 0.10) increase Ruminococcus flavefaciens and decrease (P < 0.05) Ruminococcus albus copy numbers. In conclusion, bison inoculum increased the degradation of feed protein and fiber. A mixture of cattle and bison rumen inoculum acted synergistically, increasing the DM and aNDF disappearance of barley straw. PMID:28018336

  17. IDENTITY OF THE PINK-PIGMENTED METHANOL-OXIDIZING BACTERIA AS VIBRIO EXTORQUENS

    PubMed Central

    Stocks, Peter K.; McCleskey, C. S.

    1964-01-01

    Stocks, Peter K. (Louisiana State University, Baton Rouge), and C. S. McCleskey. Identity of the pink-pigmented methanol-oxidizing bacteria as Vibrio extorquens. J. Bacteriol. 88:1065–1070. 1964.—Pink-pigmented bacteria isolated from enrichment cultures of methane oxidizers were found to possess similar morphological, cultural, and physiological characteristics. All the strains utilized methanol, formate, oxalate, succinate, glycerol, and benzene as sole carbon sources; methanol, formate, and glycerol afforded best growth. Most strains utilized fructose and ribose; other carbohydrates tested were not available as carbon and energy sources. There was strain variation in the use of hexane, heptane, n-propanol, n-butanol, acetate, and propionate. Methane, ethane, n-propane, and n-butane were not utilized. Our isolates, and Pseudomonas methanica of Harrington and Kallio (not the methane-dependent P. methanica of Dworkin and Foster), Pseudomonas AM1 of Peele and Quayle, Pseudomonas PRL-W4 of Kaneda and Roxburgh, and Protaminobacter ruber den Dooren de Jong are nearly identical with Vibrio extorquens (Bassalik) Bhat and Barker, and should be considered the same species. Images PMID:14219020

  18. IDENTITY OF THE PINK-PIGMENTED METHANOL-OXIDIZING BACTERIA AS VIBRIO EXTORQUENS.

    PubMed

    STOCKS, P K; MCCLESKEY, C S

    1964-10-01

    Stocks, Peter K. (Louisiana State University, Baton Rouge), and C. S. McCleskey. Identity of the pink-pigmented methanol-oxidizing bacteria as Vibrio extorquens. J. Bacteriol. 88:1065-1070. 1964.-Pink-pigmented bacteria isolated from enrichment cultures of methane oxidizers were found to possess similar morphological, cultural, and physiological characteristics. All the strains utilized methanol, formate, oxalate, succinate, glycerol, and benzene as sole carbon sources; methanol, formate, and glycerol afforded best growth. Most strains utilized fructose and ribose; other carbohydrates tested were not available as carbon and energy sources. There was strain variation in the use of hexane, heptane, n-propanol, n-butanol, acetate, and propionate. Methane, ethane, n-propane, and n-butane were not utilized. Our isolates, and Pseudomonas methanica of Harrington and Kallio (not the methane-dependent P. methanica of Dworkin and Foster), Pseudomonas AM1 of Peele and Quayle, Pseudomonas PRL-W4 of Kaneda and Roxburgh, and Protaminobacter ruber den Dooren de Jong are nearly identical with Vibrio extorquens (Bassalik) Bhat and Barker, and should be considered the same species.

  19. 21 CFR 582.3221 - Calcium propionate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium propionate. 582.3221 Section 582.3221 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3221 Calcium propionate. (a) Product. Calcium propionate. (b) Conditions of use. This substance is...

  20. 21 CFR 582.3221 - Calcium propionate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium propionate. 582.3221 Section 582.3221 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3221 Calcium propionate. (a) Product. Calcium propionate. (b) Conditions of use. This substance is...

  1. 21 CFR 582.3784 - Sodium propionate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium propionate. 582.3784 Section 582.3784 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3784 Sodium propionate. (a) Product. Sodium propionate. (b) Conditions of use. This substance is...

  2. 21 CFR 582.3784 - Sodium propionate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium propionate. 582.3784 Section 582.3784 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3784 Sodium propionate. (a) Product. Sodium propionate. (b) Conditions of use. This substance is...

  3. 21 CFR 582.3784 - Sodium propionate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium propionate. 582.3784 Section 582.3784 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3784 Sodium propionate. (a) Product. Sodium propionate. (b) Conditions of use. This substance is...

  4. 21 CFR 582.3784 - Sodium propionate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium propionate. 582.3784 Section 582.3784 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3784 Sodium propionate. (a) Product. Sodium propionate. (b) Conditions of use. This substance is...

  5. 21 CFR 582.3784 - Sodium propionate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium propionate. 582.3784 Section 582.3784 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3784 Sodium propionate. (a) Product. Sodium propionate. (b) Conditions of use. This substance is...

  6. 21 CFR 582.3221 - Calcium propionate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium propionate. 582.3221 Section 582.3221 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3221 Calcium propionate. (a) Product. Calcium propionate. (b) Conditions of use. This substance is...

  7. 21 CFR 582.3221 - Calcium propionate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium propionate. 582.3221 Section 582.3221 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3221 Calcium propionate. (a) Product. Calcium propionate. (b) Conditions of use. This substance is...

  8. 21 CFR 582.3221 - Calcium propionate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium propionate. 582.3221 Section 582.3221 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3221 Calcium propionate. (a) Product. Calcium propionate. (b) Conditions of use. This substance is...

  9. Organic acid-tolerant microorganisms and uses thereof for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-05-06

    Organic acid-tolerant microorganisms and methods of using same. The organic acid-tolerant microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid (3HP), acrylic acid, and propionic acid. Further modifications to the microorganisms such as increasing expression of malonyl-CoA reductase and/or acetyl-CoA carboxylase provide or increase the ability of the microorganisms to produce 3HP. Methods of generating an organic acid with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers include replacing acsA or homologs thereof in cells with genes of interest and selecting for the cells comprising the genes of interest with amounts of organic acids effective to inhibit growth of cells harboring acsA or the homologs.

  10. Removal and recovery of inhibitory volatile fatty acids from mixed acid fermentations by conventional electrodialysis.

    PubMed

    Jones, Rhys Jon; Massanet-Nicolau, Jaime; Guwy, Alan; Premier, Giuliano C; Dinsdale, Richard M; Reilly, Matthew

    2015-08-01

    Hydrogen production during dark fermentation is inhibited by the co-production of volatile fatty acids (VFAs) such as acetic and n-butyric acid. In this study, the effectiveness of conventional electrodialysis (CED) in reducing VFA concentrations in model solutions and hydrogen fermentation broths is evaluated. This is the first time CED has been reported to remove VFAs from hydrogen fermentation broths. During 60 min of operation CED removed up to 99% of VFAs from model solutions, sucrose-fed and grass-fed hydrogen fermentation broths, containing up to 1200 mg l(-1) each of acetic acid, propionic acid, i-butyric acid, n-butyric acid, i-valeric acid, and n-valeric acid. CED's ability to remove VFAs from hydrogen fermentation broths suggests that this technology is capable of improving hydrogen yields from dark fermentation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Yarrowia lipolytica NCIM 3589, a tropical marine yeast, degrades bromoalkanes by an initial hydrolytic dehalogenation step.

    PubMed

    Vatsal, Aakanksha; Zinjarde, Smita S; Kumar, Ameeta Ravi

    2015-04-01

    The widespread industrial use of organobromines which are known persistent organic pollutants has led to their accumulation in sediments and water bodies causing harm to animals and humans. While degradation of organochlorines by bacteria is well documented, information regarding degradation pathways of these recalcitrant organobromines is scarce. Hence, their fates and effects on the environment are of concern. The present study shows that a tropical marine yeast, Yarrowia lipolytica NCIM 3589 aerobically degrades bromoalkanes differing in carbon chain length and position of halogen substitution viz., 2-bromopropane (2-BP), 1-bromobutane (1-BB), 1,5 dibromopentane (1,5-DBP) and 1-bromodecane (1-BD) as seen by an increase in cell mass, release of bromide and concomitant decrease in concentration of brominated compound. The amount of bromoalkane degraded was 27.3, 21.9, 18.0 and 38.3 % with degradation rates of 0.076, 0.058, 0.046 and 0.117/day for 2-BP, 1-BB, 1,5-DBP and 1-BD, respectively. The initial product formed respectively were alcohols viz., 2-propanol, 1-butanol, 1-bromo, 5-pentanol and 1-decanol as detected by GC-MS. These were further metabolized to fatty acids viz., 2-propionic, 1-butyric and 1-decanoic acid eventually leading to carbon dioxide formation. Neither higher chain nor brominated fatty acids were detected. An inducible extracellular dehalogenase responsible for removal of bromide was detected with activities of 21.07, 18.82, 18.96 and 26.67 U/ml for 2-BP, 1-BB, 1,5-DBP and 1-BD, respectively. We report here for the first time the proposed aerobic pathway of bromoalkane degradation by an eukaryotic microbe Y. lipolytica 3589, involving an initial hydrolytic dehalogenation step.

  12. Effect of sodium, potassium, magnesium, and calcium salt cations on pH, proteolysis, organic acids, and microbial populations during storage of full-fat Cheddar cheese.

    PubMed

    McMahon, D J; Oberg, C J; Drake, M A; Farkye, N; Moyes, L V; Arnold, M R; Ganesan, B; Steele, J; Broadbent, J R

    2014-01-01

    Sodium reduction in cheese can assist in reducing overall dietary Na intake, yet saltiness is an important aspect of cheese flavor. Our objective was to evaluate the effect of partial substitution of Na with K on survival of lactic acid bacteria (LAB) and nonstarter LAB (NSLAB), pH, organic acid production, and extent of proteolysis as water-soluble nitrogen (WSN) and protein profiles using urea-PAGE, in Cheddar cheese during 9mo of storage. Seven Cheddar cheeses with molar salt contents equivalent to 1.7% salt but with different ratios of Na, K, Ca, and Mg cations were manufactured as well as a low-salt cheese with 0.7% salt. The 1.7% salt cheeses had a mean composition of 352g of moisture/kg, 259g of protein/kg and 50% fat-on-dry-basis, and 17.5g of salt/kg (measured as Cl(-)). After salting, a faster initial decrease in cheese pH occurred with low salt or K substitution and it remained lower throughout storage. No difference in intact casein levels or percentage WSN levels between the various cheeses was observed, with the percentage WSN increasing from 5% at d 1 to 25% at 9mo. A greater decrease in intact αs1-casein than β-casein was detected, and the ratio of αs1-casein (f121-199) to αs1-casein could be used as an index of ripening. Typical changes in bacteria microflora occurred during storage, with lactococci decreasing gradually and NSLAB increasing. Lowering the Na content, even with K replacement, extended the crossover time when NSLAB became dominant. The crossover time was 4.5mo for the control cheese and was delayed to 5.2, 6.0, 6.1, and 6.2mo for cheeses with 10, 25, 50, and 75% K substitution. Including 10% Mg or Ca, along with 40% K, further increased crossover time, whereas the longest crossover time (7.3mo) was for low-salt cheese. By 9mo, NSLAB levels in all cheeses had increased from initial levels of ≤10(2) to approximately 10(6)cfu/g. Lactococci remained at 10(6) cfu/g in the low-salt cheese even after 9mo of storage. The propionic acid concentration in the cheese increased when NSLAB numbers were high. Few other trends in organic acid concentration were observed as a function of Na content. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Effect of cold water and inverse lighting on growth performance of broiler chickens under extreme heat stress.

    PubMed

    Park, Sang-oh; Park, Byung-sung; Hwangbo, Jong

    2015-07-01

    The present study was carried out to investigate the effect of provision of extreme heat stress diet (EHD), inverse lighting, cold water on growth performance of broiler chickens exposed to extreme heat stress. The chickens were divided into four treatment groups, (T1, T2, T3, T4) as given below: Ti (EHD 1, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T2 (EHD 2, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T3 (EHD 1, 09:00-18:00 dark, 18:00-09:00 light, cool water 141C); T4 (EHD 2, 09:00-18:00 dark, 18:00-09:00 light, cool water 14 degrees C. EHD 1 contained soybean oil, molasses, methionine and lysine; EHD 2 contained the same ingredients as EHD 1 with addition of vitamin C. Groups T1 and T2 were given cooler water than the othertwo groups, and displayed higher body weight increase and diet intake as compared to T3 and T4 (p<0.05). The weights of their liver and gizzard were similar but the weights of the thymus and bursa of fabricius (F) were higher in groups T1 and T2 (p<0.05). It was observed that groups T1 and T2 displayed higher concentrations of blood triglyceride, total cholesterol, HDL-cholesterol and blood sugar as compared to T3 and T4; however LDL-cholesterol level was higher in groups T3 and T4 (p<0.05). T1 and T2 displayed higher levels of immunity substances such as IgG, IgAand IgM as compared to T3 and T4, but the blood level of corticosterone was lower in groups T1 and T2 (p<0.05). Ti and T2 contained higher amount of fecal Lactobacill as compared to T3 and T4; howeverT3 and T4 contained higher amount of fecal E. coli, total aerobic bacteria and coliform bacteria (p<0.05). Groups T1 and T2 displayed higher concentrations of cecal total short chain fatty acids, acetic acid and propionic acid but groups T3 and T4 displayed higher concentrations of butyric acid, isobutyric acid, valeric acid and isovaleric acid (p<0.05). The present study reports novel results such that the supply of extreme heat stress diet, inverse lighting (10:00-19:00 dark, 19:00-10:00 light) with cold water at 9 degrees C under extreme heat stress could enhance growth performance of broiler chickens.

  14. Use of Lactobacillus plantarum fermentation products in bread-making to prevent Bacillus subtilis ropy spoilage.

    PubMed

    Valerio, Francesca; De Bellis, Palmira; Lonigro, Stella L; Visconti, Angelo; Lavermicocca, Paola

    2008-03-20

    Four fermentation products (FPs) of the lactic acid bacterium Lactobacillus plantarum ITM21B were screened for their anti-Bacillus activity in vitro and in bread-making trials. Results of the storage tests performed with loaves prepared with an FP or calcium propionate demonstrated that after 3 days at 30 degrees C, gross spoilage was evident in only the control loaves, which contained Bacillus subtilis at numbers of about 10(9) cfu/g. The highest inhibitory activity was shown by DM-FP obtained by growing L. plantarum in a defined medium (DM). Significantly, this medium contained an amino acceptor of the aminoacid transamination, namely alpha-ketoglutaric acid, and an aminoacid pool. With loaves prepared using the DM-acid mixture which simulated the DM-FP composition, the same reduction of ropy spoilage as with DM-FP was obtained after 3 days, while the efficacy of the mixture decreased after 7 days. This result suggests the potential involvement of some unknown metabolites in the inhibitory activity of DM-FP. In baked products made with flour based media (M1-FP, M2-FP, M3-FP), no ropy symptoms were noticeable after 3 days storage although a considerable Bacillus count was detected. DM-FP was as effective as calcium propionate (0.3% w/w, based on flour mass) in prolonging the Bacillus free-shelf life of yeast-leavened bread for 7 days.

  15. In situ degradability and selected ruminal constituents of sheep fed with peanut forage hay.

    PubMed

    Fernandes, Gisele Machado; Possenti, Rosana Aparecida; Teixeira de Mattos, Waldssimiler; Schammass, Eliana Aparecida; Junior, Evaldo Ferrari

    2013-01-01

    Because legumes are a very important feed source for ruminants, the aim of this study was to evaluate the ideal inclusion level of hay Arachis pintoi cv. Belmonte in sheep diets by measuring the dry matter intake (DMI), concentration of volatile fatty acids, ammonia-nitrogen concentration, ruminal pH and the in situ degradability of dry matter (DM) and crude protein (CP). In the experiment with four sheep, a 4 × 4 Latin Square design was used with four periods and four treatments (0%, 30%, 60% and 100% Arachis replacing grass hay). Significant interactions were observed between treatments and sampling times for ammonia-nitrogen and acetate, propionate and butyrate concentration and the acetate:propionate ratio. The ruminal pH and total volatile fatty acids concentration were not affected by interaction between treatments and sampling time. The degradation of DM and CP was similar, rising with the increasing content of Arachis, showing a linear effect. The treatment containing 60% of Arachis showed best results, with good levels of daily weight gain and higher ruminal concentrations of volatile fatty acids. The legume showed high levels of CP, high digestibility and appropriate levels of fibre, with excellent standards of degradation and ruminal characteristics. The use of the legume  Arachis for ruminants is a promising option of nutrient supply to meet production demands of these animals.

  16. Effect of Microbial and Chemical Combo Additives on Nutritive Value and Fermentation Characteristic of Whole Crop Barley Silage

    PubMed Central

    Kim, Dong Hyeon; Amanullah, Sardar M.; Lee, Hyuk Jun; Joo, Young Ho; Kim, Sam Churl

    2015-01-01

    This study was conducted to assess the effects of microbial and chemical combo additives on nutritive values, fermentation indices and aerobic stability of whole crop barley silage. Barley forage (Youngyang) was harvested at about 30% dry matter (DM) by treatments, chopped to 5 cm length and treated with distilled water only (CON), Lactobacillus plantarum (INO), propionic acid (PRO) or an equal mixture of INO and PRO (MIX). Barley forages were ensiled in 4 replications for 0, 2, 7, and 100 days. On 100 days of ensiling, MIX silage had higher (p<0.05) in vitro DM digestibility than CON silage, but lower (p<0.05) acid detergent fiber concentration. The pH in all treated silages was lower (p<0.05) than CON silage. The MIX silage had higher (p<0.05) lactate concentration and lactate to acetate ratio than in CON, but lower (p<0.05) yeast count. Aerobic stability in CON, PRO, and MIX silages were higher (p<0.05) than in INO silage. It is concluded that microbial and chemical combo additives using L. plantarum and propionic acid could efficiently improve nutritive values of barley silage in terms of increased in vitro DM digestibility compared to other treatments. In addition, all treatments except CON reduced yeast count which is the initiate microorganism of aerobic spoilage. PMID:26323517

  17. Genome-wide ChIP-seq mapping and analysis of butyrate-induced H3K9 and H3K27 acetylation and epigenomic landscapes alteration in bovine cells

    USDA-ARS?s Scientific Manuscript database

    Volatile short-chain fatty acids (VFAs, acetate, propionate, and butyrate) are nutrients especially critical to ruminants. Beyond their nutritional impact, clear evidence is beginning to link modifications in chromatin structure induced by butyrate to cell cycle progression, DNA replication and over...

  18. Storage characteristics, nutritive value, energy content, and in-vivo digestibility of moist large-rectangular bales of alfalfa-orchardgrass hay treated with a propionic-acid-based preservative

    USDA-ARS?s Scientific Manuscript database

    Unstable weather, poor drying conditions, and unpredictable rainfall events often place valuable hay crops at risk. Recent research with large-round bales comprised of alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) has shown that these large-bale packages are particularly sens...

  19. Functionalization of 6-nitrobenzo[1,3]dioxole with carbonyl compounds via TDAE methodology.

    PubMed

    Amiri-Attou, Ouassila; Terme, Thierry; Vanelle, Patrice

    2005-05-13

    We report herein the synthesis of substituted 2-(6-nitrobenzo[1,3]dioxol-5-yl)-1- aryl ethanols and 2-(6-nitrobenzo[1,3]dioxol-5-yl)-propionic acid ethyl esters from the reaction of 5-chloromethyl-6-nitrobenzo[1,3]dioxole with various aromatic carbonyl and alpha- carbonyl ester derivatives using the tetrakis(dimethylamino)ethylene (TDAE) methodology.

  20. Effect of sole or combined administration of nitrate and 3-nitro-1-propionic acid on fermentation and Salmonella survivability in alfalfa-fed rumen cultures in vitro

    USDA-ARS?s Scientific Manuscript database

    Ruminal methanogenesis is a digestive inefficiency resulting in the loss of dietary energy consumed by the host and contributing to environmental methane emission. Nitrate is being investigated as a feed supplement to reduce rumen methane emissions, but safety and efficacy concerns persist. To ass...

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