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1

Aerobic mesophilic and psychrotrophic sporeforming bacteria in buffalo milk.  

PubMed

Seasonal variation of the population of aerobic sporeformers in raw milk was higher in summer than in other seasons. Least variation was in fall, but variation in winter and spring was similar. Aerobic mesophilic sporeformers in raw milk consisted mainly of Bacillus subtilis (42.5%) and Bacillus megaterium (34.8%), followed by Bacillus circulans (4.9%), Bacillus cereus (4.6%), Bacillus pumilus (2.9%), Bacillus polymyxa (2.8%), Bacillus licheniformis (1.9%), Bacillus badius (1.5%), Bacillus brevis (1.3%), Bacillus pulvifaciens (1.2%), Bacillus coagulans (1.1%), and Bacillus firmus (.5%). Comparing these findings with those previously obtained for the same area reveal noticeable variations. The psychrotrophic Bacillus strains were cereus (42.6%), pumilus (31.9%), badius (12.8%), licheniformis (10.6%), and firmus (2.1%). PMID:6886164

Shehata, A E; Magdoub, M N; Sultan, N E; El-Samragy, Y A

1983-06-01

2

Effect of hot water spray on broiler carcasses for reduction of loosely attached, intermediately attached, and tightly attached pathogenic (Salmonella and Campylobacter) and mesophilic aerobic bacteria.  

PubMed

Chickens are known to harbor many bacteria, including pathogenic microorganisms such as Salmonella and Campylobacter. The objective of this study was to evaluate the efficacy of hot water spray (HWS, 71°C for 1 min) in reducing bacterial contamination of prechilled broiler carcasses. For each of 4 replications, skin samples from 5 broilers were collected at 3 processing stages: after bleeding (feathers removed manually), after evisceration (with/without HWS), and after water chilling. Broiler skin was quantitatively assessed for loosely attached (by rinsing the skin), intermediately attached (by stomaching the rinsed skin), and tightly attached (by grinding the rinsed/stomached skin) mesophilic aerobic bacteria (MAB) and Campylobacter as well as for the prevalence of Salmonella and Campylobacter. Broiler skins possessed 6.4 to 6.6 log cfu/g, 3.8 to 4.1 log cfu/g, and 2.8 to 3.5 log cfu/g of MAB populations after bleeding, evisceration, and chilling, respectively. The HWS resulted in more than 1 log unit of reduction in MAB immediately after evisceration and immediately after chilling regardless of microbial sampling method. Compared with MAB, the contamination of Campylobacter was low (1.7 to 2.6 log cfu/g) after bleeding, but the level was not reduced throughout the processing steps regardless of HWS. The application of HWS reduced the prevalence of Salmonella after chilling, but not for Campylobacter except for loosely attached cells. After hot water exposure, a partially cooked appearance was seen on both broiler skin and skinless breast surface. More research is required to effectively eliminate pathogenic organisms during processing and suppress any recovery of bacteria regardless of attachment type after chilling. PMID:23436532

Zhang, L; Singh, P; Lee, H C; Kang, I

2013-03-01

3

Effect of inoculation of mesophilic lactic acid bacteria on microbial and sensory changes of minced goat meat during storage under vacuum and subsequent aerobic storage  

Microsoft Academic Search

Minced goat meat inoculated with cell suspensions of Lactococcus lactis ssp lactis (Lc. lactis) or Lactobacillus plantarum was stored under vacuum in PETPE film at 4°C and transferred to aerobic storage for 7 days in LDPE bags. During storage under vacuum, the lactic counts of the inoculated samples dropped followed by the development of spontaneous lactic flora. The pH of

Y. Babji; T. R. K. Murthy

2000-01-01

4

Technical note: enumeration of mesophilic aerobes in milk: evaluation of standard official protocols and petrifilm aerobic count plates  

Microsoft Academic Search

Enumeration of mesophilic aerobes (MA) is the main quality and hygiene parameter for raw and pasteur- ized milk. High levels of these microorganisms indicate poor conditions in production, storage, and processing of milk, and also the presence of pathogens. Fifteen raw and 15 pasteurized milk samples were submitted for MA enumeration by a conventional plating method (using plate count agar)

F. Carvalho

5

The correlation between aerobic mesophilic microorganism counts and Dornic acidity in expressed human breastmilk  

Microsoft Academic Search

Objective: The study was designed to test for the existence of a correlation between the total population of aerobicmesophilicmicroorganismsinprocessedrawbreastmilkfromahumanmilkbankandtheDornicacidityofthat milk. Methods: Two hundred consecutive samples of thawed expressed human breastmilk obtained from human milk bank, prior to pasteurization. Dornic acidity was titrated in triplicate for each sample. aerobic mesophilic microorganisms were then plate counted. Data were analyzed to detect correlations

Franz R. Novak; Dea M. B. Cordeiro

2007-01-01

6

Evaluation of conditioning responses of thermophilic-mesophilic anaerobically and mesophilic aerobically digested biosolids using rheological properties.  

PubMed

One of the most crucial processes in biosolids management is stabilisation, which is typically accomplished using either anaerobic or aerobic digestion processes. Although there are many advantages to both of these methods--such as reduction of volatile organic matter, pathogen content, and offensive odours--one common disadvantage is that digested biosolids exhibit poor dewaterability characteristics. The deterioration in dewaterability of digested biosolids leads to increases in polymer requirements, connoting higher conditioning costs. Many studies have examined this phenomenon based on conventional filterability tests such as capillary suction time and specific resistance to filtration. However, these test methods are limited in their ability to predict full-scale dewatering behaviour (particularly in centrifugation), and do not regard handling properties as being important for sludge transport. For this purpose, new rheometric methods may assist in predicting sludge behaviour, potentially allowing optimisation of stabilisation and conditioning processes relative to the desired sludge properties. This paper investigates the possible utility of these methods. Classical methods for characterising biosolids, such as filtration tests, are compared with yield stress values and other rheological properties as determined using the steady-shear rate sweep test. The rheological behaviours are compared for different sludge types, including raw and polymer conditioned thermophilic anaerobically, mesophilic anaerobically, and mesophilic aerobically digested biosolids. The paper demonstrates the determination of specific energy values associated with breakdown of the flocculated matrix. Robust modelling approaches are employed to optimise the conditioning of the digested samples, and to shed light on commonly used rheological models such as Bingham, Herschel-Bulkley, and Ostwald equations. PMID:17087366

Ayol, A; Filibeli, A; Dentel, S K

2006-01-01

7

Conversion of Cellulose to Ethanol by Mesophilic Bacteria. Progress Report, July 15, 1983-February 15, 1985.  

National Technical Information Service (NTIS)

Highlights of accomplishments during the period from July 1983 to February 1985 are summarized. Research has dealt primarily with strains of obligately anaerobic, mesophilic cellulolytic bacteria that we isolated from various natural environments. Eight s...

E. Canale-Parola

1985-01-01

8

Aerobic Succinate Production in Bacteria.  

National Technical Information Service (NTIS)

Methods of increasing yields of succinate using aerobic culture methods and a multi-mutant E. coli strain are provided. Also provided is a mutant strain of E. coli that produces high amounts of succinic acid.

G. N. Bennett H. Lin K. Y. San

2004-01-01

9

Conversion of cellulose to ethanol by mesophilic bacteria. Progress report and third year budget  

Microsoft Academic Search

Much of our research has dealt with eight strains of obligately anaerobic bacteria that we isolated from various natural environments as described in last year's progress report. These eight strains (referred to as C strains) are strains of mesophilic, spore-forming, rod-shaped bacteria that ferment cellulose with production of ethanol. We determined quantitatively the fermentation products formed by C strains from

Canale-Parola

1982-01-01

10

Microbial community structure in a thermophilic aerobic digester used as a sludge pretreatment process for the mesophilic anaerobic digestion and the enhancement of methane production.  

PubMed

An effective two-stage sewage sludge digestion process, consisting of thermophilic aerobic digestion (TAD) followed by mesophilic anaerobic digestion (MAD), was developed for efficient sludge reduction and methane production. Using TAD as a biological pretreatment, the total volatile suspended solid reduction (VSSR) and methane production rate (MPR) in the MAD reactor were significantly improved. According to denaturing gradient gel electrophoresis (DGGE) analysis, the results indicated that the dominant bacteria species such as Ureibacillus thermophiles and Bacterium thermus in TAD were major routes for enhancing soluble organic matter. TAD pretreatment using a relatively short SRT of 1day showed highly increased soluble organic products and positively affected an increment of bacteria populations which performed interrelated microbial metabolisms with methanogenic species in the MAD; consequently, a quantitative real-time PCR indicated greatly increased Methanosarcinales (acetate-utilizing methanogens) in the MAD, resulting in enhanced methane production. PMID:23419990

Jang, Hyun Min; Park, Sang Kyu; Ha, Jeong Hyub; Park, Jong Moon

2013-01-29

11

Total mesophilic counts underestimate in many cases the contamination levels of psychrotrophic lactic acid bacteria (LAB) in chilled-stored food products at the end of their shelf-life.  

PubMed

The major objective of this study was to determine the role of psychrotrophic lactic acid bacteria (LAB) in spoilage-associated phenomena at the end of the shelf-life of 86 various packaged (air, vacuum, modified-atmosphere) chilled-stored retail food products. The current microbiological standards, which are largely based on the total viable mesophilic counts lack discriminatory capacity to detect psychrotrophic LAB. A comparison between the total viable counts on plates incubated at 30 °C (representing the mesophiles) and at 22 °C (indicating the psychrotrophs) for 86 food samples covering a wide range - ready-to-eat vegetable salads, fresh raw meat, cooked meat products and composite food - showed that a consistent underestimation of the microbial load occurs when the total aerobic mesophilic counts are used as a shelf-life parameter. In 38% of the samples, the psychrotrophic counts had significantly higher values (+0.5-3 log CFU/g) than the corresponding total aerobic mesophilic counts. A total of 154 lactic acid bacteria, which were unable to proliferate at 30 °C were isolated. In addition, a further 43 with a poor recovery at this temperature were also isolated. This study highlights the potential fallacy of the total aerobic mesophilic count as a reference shelf-life parameter for chilled food products as it can often underestimate the contamination levels at the end of the shelf-life. PMID:22986212

Pothakos, Vasileios; Samapundo, Simbarashe; Devlieghere, Frank

2012-08-07

12

Biology of Moderately Halophilic Aerobic Bacteria  

PubMed Central

The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms.

Ventosa, Antonio; Nieto, Joaquin J.; Oren, Aharon

1998-01-01

13

Conversion of cellulose to ethanol by mesophilic bacteria. Progress report, July 15, 1983-February 15, 1985  

SciTech Connect

Highlights of accomplishments during the period from July 1983 to February 1985 are summarized. Research has dealt primarily with strains of obligately anaerobic, mesophilic cellulolytic bacteria that we isolated from various natural environments. Eight strains (referred to as C strains) were isolated from mud of freshwater environments. As described in the previous progress report, the C strains represented a species of Clostridium that was different from other described species. The C strains fermented cellulose with formation of ethanol. They differed from thermophilic cellulolytic clostridia (e.g. Clostridium thermocellum) not only in growth temperature range, but also because they fermented xylan and pentoses with formation of ethanol. This result indicated that these mesophilic clostridia can convert to ethanol both cellulosic and hemicellulosic components of biomass. In contrast, monocultures of Clostridium thermocellum ferment only the cellulosic component of biomass. Furthermore, cellulose was degraded by the C strains at a rate comparable to that of thermophilic cellulolytic clostridia. These observations indicated that the mesophilic cellulolytic isolates constituted potentially useful microorganisms for ethanol production from biomass.

Canale-Parola, E.

1985-03-15

14

Previously unclassified bacteria dominate during thermophilic and mesophilic anaerobic pre-treatment of primary sludge.  

PubMed

Thermophilic biological pre-treatment enables enhanced anaerobic digestion for treatment of wastewater sludges but, at present, there is limited understanding of the hydrolytic-acidogenic microbial composition and its contribution to this process. In this study, the process was assessed by comparing the microbiology of thermophilic (50-65 °C) and mesophilic (35 °C) pre-treatment reactors treating primary sludge. A full-cycle approach for the 16S rRNA genes was applied in order to monitor the diversity of bacteria and their abundance in a thermophilic pre-treatment reactor treating primary sludge. For the thermophilic pre-treatment (TP), over 90% of the sequences were previously undetected and these had less than 97% sequence similarity to cultured organisms. During the first 83 days, members of the Betaproteobacteria dominated the community sequences and a newly designed probe was used to monitor a previously unknown bacterium affiliated with the genus Brachymonas. Between days 85 and 183, three phylotypes that affiliated with the genera Comamonas, Clostridium and Lysobacter were persistently dominant in the TP community, as revealed by terminal-restriction fragment length polymorphism (T-RFLP). Hydrolytic and fermentative functions have been speculated for these bacteria. Mesophilic pre-treatment (MP) and TP communities were different but they were both relatively dynamic. Statistical correlation analysis and the function of closely allied reference organisms indicated that previously unclassified bacteria dominated the TP community and may have been functionally involved in the enhanced hydrolytic performance of thermophilic anaerobic pre-treatment. This study is the first to reveal the diversity and dynamics of bacteria during anaerobic digestion of primary sludge. PMID:23643091

Pervin, Hasina M; Batstone, Damien J; Bond, Philip L

2013-05-01

15

Conversion of cellulose to ethanol by mesophilic bacteria. Progress report and third year budget  

SciTech Connect

Much of our research has dealt with eight strains of obligately anaerobic bacteria that we isolated from various natural environments as described in last year's progress report. These eight strains (referred to as C strains) are strains of mesophilic, spore-forming, rod-shaped bacteria that ferment cellulose with production of ethanol. We determined quantitatively the fermentation products formed by C strains from cellulose and various other carbohydrates. In all cases ethanol was produced, as well as acetate, CO/sub 2/ and H/sub 2/. The C strains utilized, for ethanol production and growth, a variety of cellulosic substrates ranging from paper to alpha-cellulose. Enzymatic assays and growth studies showed that C strains possessed a celluloase system consisting of endoglucanase, exoglucanase, and cellobiase components. Studies indicated that growth substrates have a regulatory effect(s) on components of the cellulase system of the C strains. another experimental approach is aimed at cloning cellobiase, endoglucanase and exoglucanase genes from the C strains into a suitable vector plasmid and, eventually, at introducing the plasmid into cells of Zymomonas mobilis. The objective of this part of our research is to obtain a Z. mobilis strain capable of fermenting cellobiose and/or cellulose. Plasmids that contained DNA inserts were used to transform E. coli C600 recA. E. coli transformants that had acquired the cellobiase gene were obtained by this procedure. At present, we are attempting to introduce into Z. mobilis cells the vector plasmid purified from the E. coli transformants. In another series of experiments, we have used a new selective procedure to isolate four additional strains of mesophilic, obligately anaerobic, cellulolytic bacteria from natural environments.

Canale-Parola, E.

1982-11-24

16

Conversion of cellulose to ethanol by mesophilic bacteria: Final report, July 15, 1984-November 14, 1987  

SciTech Connect

The physiology and genetics of mesophilic cellulose-fermenting, ethanol-producing bacteria were investigated in order to develop strains of bacteria that can be used in the conversion of biomass materials to ethanol. Studies involved, primarily, a species of Clostridium (strain C7) isolated from the sediment of a freshwater swamp. A cellulose-fermenting bacterium from wetwood and several strains of nitrogen-fixing cellulose-fermenting bacteria from soil were also investigated. As a first step to understanding the genetic organization of the cellulase system of these bacteria, enzymes associated with the hydrolysis of cellulosic materials by strain C7 were characterized. Crystalline cellulose was solubilized by a 700,000 molecular weight complex comprised of approximately 18 polypeptides. This complex was required in its entirety to degrade crystalline cellulose, inasmuch as this activity was lost when the complex was disrupted into its constituent proteins. Studies involving a cellulase-deficient mutant supported this conclusion. Other enzymes that were investigated included ..beta..-glucosidase and cellobiose phosphorylase. Also, a strain C7 gene encoding ..beta..-xylosidase was cloned in E. coli. Enzyme purified from E. coli cells containing the cloned clostridial gene had a molecular weight of 240,000. A bacteriophage of strain C7 was isolated and characterized, and methods for forming protoplasts and regenerating cell walls of strain C7 were developed. 10 refs.

Canale-Parola, E.; Dowell, C.E.; Leschine, S.B.

1988-01-01

17

Soil and Sediment Bacteria Capable of Aerobic Nitrate Respiration  

Microsoft Academic Search

Several laboratory strains of gram-negative bacteria are known to be able to respire nitrate in the presence ofoxygen,althoughthephysiologicaladvantagegainedfromthisprocessisnotentirelyclear.Thecontribution that aerobic nitrate respiration makes to the environmental nitrogen cycle has not been studied. As afirst step in addressing this question, a strategy which allows for the isolation of organisms capable of reducing nitrate to nitrite following aerobic growth has been developed.

JON P. CARTER; YA HSIN HSIAO; STEPHEN SPIRO; ANDDAVID J. RICHARDSON

1995-01-01

18

Aerobic, Endospore-Forming Bacteria from Antarctic Geothermal Soils  

Microsoft Academic Search

The term ‘aerobic endospore-forming bacteria’ is used to embrace Bacillus species and related genera, for which the production of resistant endospores in the presence of oxygen remains the defining\\u000a feature. They are also expected to possess Gram-positive cell wall structures (but staining reactions, even in young cultures,\\u000a may be Gram-variable or frankly Gram-negative), and may be aerobic or facultatively anaerobic.

Niall A. Logan A. Logan; Raymond N. Allan N. Allan

19

Conversion of cellulose to ethanol by mesophilic bacteria. Progress report and second year budget  

SciTech Connect

Eight strains of anaerobic mesophilic cellulolytic bacteria were isolated from the mud of a freshwater pond and swamp. The isolation procedure involved serial dilution of the mud into cellulose-containing agar media. The isolates were rod-shaped and formed terminal, spherical to oval spores that swelled the sporangium. All strains fermented cellulose producing primarily ethanol, acetate, CO/sub 2/, and H/sub 2/. Growth and cellulose fermentation occurred between 22/sup 0/ and 40/sup 0/C, but not at 15/sup 0/ and 45/sup 0/C. The isolates differed from thermophilic cellulolytic clostridia not only in growth temperature range, but also because they fermented five-carbon products of plant polysaccharide hydrolysis, such as D-xylose and L-arabinose. Other fermentable substrates included xylan, D-glucose, cellobiose and, for three strains, D-galactose. None of the strains utilized maltose, sucrose, D-galacturonate, or amino acids as growth substrates. All isolates had a Gram-negative reaction and were motile by means of peritrichous flagella. The substrate utilization characteristics and the growth temperature range of the isolates indicate that these bacteria contribute to the anaerobic degradation of plant materials in the environments they inhabit. The isolates apparently represent a previously undescribed species of free-living cellulolytic clostridia.

Canale-Parola, E.

1981-11-27

20

Extracellular enzyme activity in anaerobic bacterial cultures: evidence of pullulanase activity among mesophilic marine bacteria.  

PubMed Central

The extracellular enzymatic activity of a mixed culture of anaerobic marine bacteria enriched on pullulan [alpha(1,6)-linked maltotriose units] was directly assessed with a combination of gel permeation chromatography (GPC) and nuclear magnetic resonance spectroscopy (NMR). Hydrolysis products of pullulan were separated by GPC into three fractions with molecular weights of > or = 10,000, approximately 5,000, and < or = 1,200. NMR spectra of these fractions demonstrated that pullulan was rapidly and specifically hydrolyzed at alpha(1,6) linkages by pullulanase enzymes, most likely type II pullulanase. Although isolated pullulanase enzymes have been shown to hydrolyze pullulan completely to maltotriose (S. H. Brown, H. R. Costantino, and R. M. Kelly, Appl. Environ. Microbiol. 56:1985-1991, 1990; M. Klingeberg, H. Hippe, and G. Antranikian, FEMS Microbiol. Lett. 69:145-152, 1990; R. Koch, P. Zablowski, A. Spreinat, and G. Antranikian, FEMS Microbiol. Lett. 71:21-26, 1990), the smallest carbohydrate detected in the bacterial cultures consisted of two maltotriose units linked through one alpha(1,6) linkage. Either the final hydrolysis step was closely linked to substrate uptake, or specialized porins similar to maltoporin might permit direct transport of large oligosaccharides into the bacterial cell. This is the first report of pullulanase activity among mesophilic marine bacteria. The combination of GPC and NMR could easily be used to assess other types of extracellular enzyme activity in bacterial cultures.

Arnosti, C; Repeta, D J

1994-01-01

21

AEROBIC SALIVARY BACTERIA IN WILD AND CAPTIVE KOMODO DRAGONS  

Microsoft Academic Search

During the months of November 1996, August 1997, and March 1998, saliva and plasma samples were collected for isolation of aerobic bacteria from 26 wild and 13 captive Komodo dragons (Varanus komodoensis). Twenty-eight Gram-negative and 29 Gram-positive spe- cies of bacteria were isolated from the saliva of the 39 Komodo dragons. A greater number of wild than captive dragons were

Joel M. Montgomery; Don Gillespie; Putra Sastrawan; Terry M. Fredeking; George L. Stewart

2002-01-01

22

Oxygen tolerance of strictly aerobic hydrogen-oxidizing bacteria  

Microsoft Academic Search

Growth of various bacteria, especially aerobic hydrogen-oxidizing bacteria, in the presence of 2 to 100% (v\\/v) oxygen in the gas atmosphere was evaluated. The bacterial strains included Alcaligenes eutrophus, A. paradoxus, Aquaspirillum autotrophicum, Arthrobacter spec. strain 11X, Escherichia coli, Arthrobacter globiformis, Nocardia opaca, N. autotrophica, Paracoccus denitrificans, Pseudomonas facilis, P. putida, and Xanthobacter autotrophicus. Under heterotrophic conditions with fructose or

E. Wilde; H. G. Schlegel

1982-01-01

23

Aerobic methanol-oxidizing bacteria in soil.  

PubMed

Methanol is an atmospheric compound that is primarily released from plant polymers and impacts ozone formation. The global methanol emission rate from terrestrial ecosystems is of the same order of magnitude (4.9 x 10(12) mol year(-1)) as that of methane (10 x 10(12) mol year(-1)). The major proportion of the annual plant-released methanol does not enter the atmosphere, but may be reoxidized by biological methanol oxidation, which is catalyzed by methanol-oxidizing prokaryotes. Fifty-six aerobic methanol-oxidizing species have been isolated from soils. These methylotrophs belong to the Alpha-, Beta-, and Gammaproteobacteria, Verrucomicrobia, Firmicutes, and Actinobacteria. Their ecological niches are determined by oxygen and methanol concentration, temperature, pH, the capability to utilize nitrate as an electron acceptor, and the spectrum of nitrogen sources and utilizable multicarbon substrates. Recently discovered interactions with eukaryotes indicate that their ecological niches may not solely be defined by physicochemical parameters. Nonetheless, there are still gaps in knowledge; based on global methanol budgets, methanol oxidation in soil is important, but has not been addressed adequately by biogeochemical studies. Ratios of above-ground and soil-internal methanol oxidation are not known. The contribution to methanol-oxidation by aerobic and anaerobic methylotrophs in situ also needs further research. PMID:19583792

Kolb, Steffen

2009-07-01

24

Characterization of aerobic spore-forming bacteria associated with industrial dairy processing environments and product spoilage.  

PubMed

Due to changes in the design of industrial food processing and increasing international trade, highly thermoresistant spore-forming bacteria are an emerging problem in food production. Minimally processed foods and products with extended shelf life, such as milk products, are at special risk for contamination and subsequent product damages, but information about origin and food quality related properties of highly heat-resistant spore-formers is still limited. Therefore, the aim of this study was to determine the biodiversity, heat resistance, and food quality and safety affecting characteristics of aerobic spore-formers in the dairy sector. Thus, a comprehensive panel of strains (n=467), which originated from dairy processing environments, raw materials and processed foods, was compiled. The set included isolates associated with recent food spoilage cases and product damages as well as isolates not linked to product spoilage. Identification of the isolates by means of Fourier-transform infrared spectroscopy and molecular methods revealed a large biodiversity of spore-formers, especially among the spoilage associated isolates. These could be assigned to 43 species, representing 11 genera, with Bacillus cereus s.l. and Bacillus licheniformis being predominant. A screening for isolates forming thermoresistant spores (TRS, surviving 100°C, 20min) showed that about one third of the tested spore-formers was heat-resistant, with Bacillus subtilis and Geobacillus stearothermophilus being the prevalent species. Strains producing highly thermoresistant spores (HTRS, surviving 125°C, 30min) were found among mesophilic as well as among thermophilic species. B. subtilis and Bacillus amyloliquefaciens were dominating the group of mesophilic HTRS, while Bacillus smithii and Geobacillus pallidus were dominating the group of thermophilic HTRS. Analysis of spoilage-related enzymes of the TRS isolates showed that mesophilic strains, belonging to the B. subtilis and B. cereus groups, were strongly proteolytic, whereas thermophilic strains displayed generally a low enzymatic activity and thus spoilage potential. Cytotoxicity was only detected in B. cereus, suggesting that the risk of food poisoning by aerobic, thermoresistant spore-formers outside of the B. cereus group is rather low. PMID:23973839

Lücking, Genia; Stoeckel, Marina; Atamer, Zeynep; Hinrichs, Jörg; Ehling-Schulz, Monika

2013-07-16

25

Studying Denitrification by Aerobic Endospore-forming Bacteria in Soil  

Microsoft Academic Search

\\u000a As part of the aerobic endospore-forming bacteria in soil, members of the genus Bacillus sensu stricto and related species are involved in denitrification – one of the main processes in the global nitrogen cycle. So far, only\\u000a limited information on the denitrification abilities and the distribution of the key denitrification genes in these organisms\\u000a is available. This chapter provides a

Ines Verbaendert; Paul De Vos

26

Aerobic and Anaerobic Starvation Metabolism in Methanotrophic Bacteria  

PubMed Central

The capacity for anaerobic metabolism of endogenous and selected exogenous substrates in carbon- and energy-starved methanotrophic bacteria was examined. The methanotrophic isolate strain WP 12 survived extended starvation under anoxic conditions while metabolizing 10-fold less endogenous substrate than did parallel cultures starved under oxic conditions. During aerobic starvation, the cell biomass decreased by 25% and protein and lipids were the preferred endogenous substrates. Aerobic protein degradation (24% of total protein) took place almost exclusively during the initial 24 h of starvation. Metabolized carbon was recovered mainly as CO(inf2) during aerobic starvation. In contrast, cell biomass decreased by only 2.4% during anaerobic starvation, and metabolized carbon was recovered mainly as organic solutes in the starvation medium. During anaerobic starvation, only the concentration of intracellular low-molecular-weight compounds decreased, whereas no significant changes were measured for cellular protein, lipids, polysaccharides, and nucleic acids. Strain WP 12 was also capable of a limited anaerobic glucose metabolism in the absence of added electron acceptors. Small amounts of CO(inf2) and organic acids, including acetate, were produced from exogenous glucose under anoxic conditions. Addition of potential anaerobic electron acceptors (fumarate, nitrate, nitrite, or sulfate) to starved cultures of the methanotrophs Methylobacter albus BG8, Methylosinus trichosporium OB3b, and strain WP 12 did not stimulate anaerobic survival. However, anaerobic starvation of these bacteria generally resulted in better survival than did aerobic starvation. The results suggest that methanotrophic bacteria can enter a state of anaerobic dormancy accompanied by a severe attenuation of endogenous metabolism. In this state, maintenance requirements are presumably provided for by fermentation of certain endogenous substrates. In addition, low-level catabolism of exogenous substrates may support long-term anaerobic survival of some methanotrophic bacteria.

Roslev, P.; King, G. M.

1995-01-01

27

Method for quantification of aerobic anoxygenic phototrophic bacteria  

Microsoft Academic Search

Accurate quantification of aerobic anoxygenic phototrophic bacteria (AAPB) is of crucial importance for estimation of the\\u000a role of AAPB in the carbon cycling in marine ecosystems. The normally used method “epifluorescence microscope-infrared photography\\u000a (EFM-IRP)” is, however, subject to positive errors introduced by mistaking cyanobacteria as AAPB due to the visibility of\\u000a cyanobacteria under infrared photographic conditions for AAPB. This error

Yao Zhang; Nianzhi Jiao

2004-01-01

28

Aerobic Respiration in the Gram-Positive Bacteria  

Microsoft Academic Search

The group of Gram-positive bacteria is a major phylum of prokaryotes, including several typical saprophytic aerobes. Their\\u000a respiratory chains are apparently similar to those of eukaryotic mitochondria, but in several points are different from them.\\u000a The respiratory chain of Gram-positives, like many bacteria, contains branched electron transfer pathways, usually 1-3 heme-Cu\\u000a oxidases, but SoxB-type cytochrome c oxidases (cytochrome b(a\\/o)3) are

Nobhuito Sone; Cecilia Hagerhall; Junshi Sakamoto

29

Biodegradation of Asphalt Cement-20 by Aerobic Bacteria  

PubMed Central

Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-degrading bacterium, Acinetobacter calcoaceticus NAV2, excretes an emulsifier which is capable of emulsifying the saturate and naphthene aromatic fractions of asphalt cement-20. This emulsifier is not denatured by phenol.

Pendrys, John P.

1989-01-01

30

Conversion of cellulose to ethanol by mesophilic bacteria. Proposal for continuation of DOE Contract DE-AC02-81ER10878  

Microsoft Academic Search

The project objective is to study the genetics of mesophilic anaerobic bacteria that ferment cellulose to ethanol. Bacteria used in this investigation are strains of Clostridium that (1) convert to ethanol not only cellulose, but also components of the hemicellulosic portion of biomass and (2) are relatively ethanol tolerant. Studies include plasmid analysis and fine-structure mapping of genes involved in

Canale-Parola

1986-01-01

31

High hydrostatic pressure inactivation of total aerobic bacteria, lactic acid bacteria, yeasts in sour Chinese cabbage  

Microsoft Academic Search

This study investigated the inactivation of total aerobic bacteria (TAB), lactic acid bacteria (LAB), yeasts in sour Chinese cabbage (SCC) treated by high hydrostatic pressure (HHP). The pressure level ranged from 200 to 600MPa and the treatment time were 10–30min. All samples were stored at 4, 27 and 37°C for 90days. The pressure level of 200MPa had no significant impact

Lin Li; Lun Feng; Junjie Yi; Cheng Hua; Fang Chen; Xiaojun Liao; Zhengfu Wang; Xiaosong Hu

2010-01-01

32

Evaluation of Cathra system for identifying gram negative aerobic bacteria.  

PubMed Central

The Cathra system is a commercial multipoint inoculation method for the identification of aerobic Gram negative bacteria. The system uses a replicator technique in which 21 different agar media can be inoculated simultaneously with 36 organisms. Identifications are made by use of a special computer database. The performance of this system was compared with that of the API 20E for the identification of 372 clinical isolates of Enterobacteriaceae and 133 miscellaneous Gram negative bacteria. For enterobacteria, the Cathra system was in 97% agreement with API 20E at species level and 98% at genus level. For miscellaneous Gram negative strains the two systems were in 59% agreement at species level and 77% at genus level. The Cathra system is suitable for use in diagnostic laboratories, especially those with a heavy workload and a wish to use break-point sensitivity testing. The identification database for miscellaneous Gram negative organisms, however, needs to be expanded.

Ling, J M; Zhang, L C; Hui, Y W; French, G L

1990-01-01

33

Oxygen tolerance of strictly aerobic hydrogen-oxidizing bacteria.  

PubMed

Growth of various bacteria, especially aerobic hydrogen-oxidizing bacteria, in the presence of 2 to 100% (v/v) oxygen in the gas atmosphere was evaluated. The bacterial strains included Alcaligenes eutrophus, A. paradoxus, Aquaspirillum autotrophicum, Arthrobacter spec. strain 11 X, Escherichia coli, Arthrobacter globiformis, Nocardia opaca, N. autotrophica, Paracoccus denitrificans, Pseudomonas facilis, P. putida, and Xanthobacter autotrophicus. Under heterotrophic conditions with fructose or gluconate as substrates neither colony formation on solid medium nor the growth rates in liquid media were drastically impaired by up to 100% oxygen. In contrast, autotrophic growth--with hydrogen, carbon dioxide and up to 80% oxygen in the gas atmosphere--was strongly depressed by high oxygen concentrations. However, only the growth rate, not the viability of the cells, was decreased. Growth retardation was accompanied by a decrease of hydrogenase activity. PMID:7049081

Wilde, E; Schlegel, H G

1982-05-01

34

The survival of cefazolin-resistant bacteria in mesophilic co-digestion of dairy manure and waste milk.  

PubMed

The use of cefazolin to treat mastitic cows leads to cefazolin residues in milk and manure. This is responsible for the high occurrence of cefazolin resistant bacteria (CRB) in waste and the environment. Anaerobic digestion is considered to have the potential to reduce antibiotic-resistant bacteria present in waste that results from concentrated animal feeding operations. Thus, the objective of this study was to investigate the survival of CRB and the digester performance in mesophilic co-digestion of dairy manure and waste milk. The experiment was carried out using three digester compositions: 100% slurry (slurry), 50% slurry + 50% manure (manure mixture) and 50% slurry + 45% manure + 5% waste milk (milk mixture) in batch digesters of 1 l with a working volume of 800 ml in triplicate at 37°C for 34 days. The daily biogas production in each digester, and methane (CH4) and carbon dioxide compositions in the gas were determined. The population densities of total culturable bacteria (TCB) and CRB were determined by plate counts on agar media at day 0, 10, 20 and 34 of digestion. Milk mixture produced the highest (P < 0.05) daily and cumulative total and CH4 gas. The maximum percentage reductions of TCB and CRB in manure and milk mixture was observed at day 20, the values being 96.2%, 96.0% and 99.8% and 99.8% respectively. Final volatile fatty acids (VFA) and pH values of the digesters confirmed the digester stability. Based on the findings, mesophilic anaerobic digestion can be considered a potent method to avoid the dissemination of CRB in nature. PMID:23512952

Beneragama, Nilmini; Moriya, Yusuke; Yamashiro, Takaki; Iwasaki, Masahiro; Lateef, Suraju A; Ying, Chun; Umetsu, Kazutaka

2013-03-19

35

Aerobic salivary bacteria in wild and captive Komodo dragons.  

PubMed

During the months of November 1996, August 1997, and March 1998, saliva and plasma samples were collected for isolation of aerobic bacteria from 26 wild and 13 captive Komodo dragons (Varanus komodoensis). Twenty-eight Gram-negative and 29 Gram-positive species of bacteria were isolated from the saliva of the 39 Komodo dragons. A greater number of wild than captive dragons were positive for both Gram-negative and Gram-positive bacteria. The average number of bacterial species within the saliva of wild dragons was 46% greater than for captive dragons. While Escherichia coli was the most common bacterium isolated from the saliva of wild dragons, this species was not present in captive dragons. The most common bacteria isolated from the saliva of captive dragons were Staphylococcus capitis and Staphylococcus capitis and Staphylococcus caseolyticus, neither of which were found in wild dragons. High mortality was seen among mice injected with saliva from wild dragons and the only bacterium isolated from the blood of dying mice was Pasteurella multocida. A competitive inhibition enzyme-linked immunosorbent assay revealed the presence of anti-Pasteurella antibody in the plasma of Komodo dragons. Four species of bacteria isolated from dragon saliva showed resistance to one or more of 16 antimicrobics tested. The wide variety of bacteria demonstrated in the saliva of the Komodo dragon in this study, at least one species of which was highly lethal in mice and 54 species of which are known pathogens, support the observation that wounds inflicted by this animal are often associated with sepsis and subsequent bacteremia in prey animals. PMID:12238371

Montgomery, Joel M; Gillespie, Don; Sastrawan, Putra; Fredeking, Terry M; Stewart, George L

2002-07-01

36

Mesophilic and Psychrotrophic Bacteria from Meat and Their Spoilage Potential In Vitro and in Beef ?  

PubMed Central

Mesophilic and psychrotrophic populations from refrigerated meat were identified in this study, and the spoilage potential of microbial isolates in packaged beef was evaluated by analyzing the release of volatile organic compounds (VOC) by gas chromatography-mass spectrometry (GC/MS). Fifty mesophilic and twenty-nine psychrotrophic isolates were analyzed by random amplified polymorphic DNA-PCR, and representative strains were identified by 16S rRNA gene sequencing. Carnobacterium maltaromaticum and C. divergens were the species most frequently found in both mesophilic and psychrotrophic populations. Acinetobacter baumannii, Buttiauxella spp. and Serratia spp. were identified among the mesophilic isolates, while Pseudomonas spp. were commonly identified among the psychrotrophs. The isolates were further characterized for their growth at different temperatures and their proteolytic activity in vitro on meat proteins extracts at 7°C. Selected proteolytic strains of Serratia proteamaculans, Pseudomonas fragi, and C. maltaromaticum were used to examine their spoilage potential in situ. Single strains of these species and mixtures of these strains were used to contaminate beef chops that were packed and stored at 7°C. At time intervals up to 1 month, viable counts were determined, and VOC were identified by GC/MS. Generally, the VOC concentrations went to increase during the storage of the contaminated meats, and the profiles of the analyzed meat changed dramatically depending on the contaminating microbial species. About 100 volatiles were identified in the different contaminated samples. Among the detected volatiles, some specific molecules were identified only when the meat was contaminated by a specific microbial species. Compounds such as 2-ethyl-1-hexanol, 2-buten-1-ol, 2-hexyl-1-octanol, 2-nonanone, and 2-ethylhexanal were detectable only for C. maltaromaticum, which also produced the highest number of aldehydes, lactones, and sulfur compounds. The highest number of alcohols and ketons were detected in the headspace of meat samples contaminated by P. fragi, whereas the highest concentrations of some alcohols, such as 1-octen-3-ol, and some esters, such as isoamyl acetate, were produced by S. proteamaculans. In conclusion, different microbial species can contribute to meat spoilage with release of different volatile compounds that concur to the overall quality decrease of spoiling meat.

Ercolini, Danilo; Russo, Federica; Nasi, Antonella; Ferranti, Pasquale; Villani, Francesco

2009-01-01

37

Isolation and characterization of mesophilic cellulose-degrading bacteria from flower stalks-vegetable waste co-composting system.  

PubMed

Fifteen mesophilic bacteria with high C(x) cellulase activities were isolated and purified from a mixed-culture enriched from a flower stalks-vegetable waste co-composting system. A CMCase test showed that the enzyme activity of these isolates ranged from 7.9 to 28.0 U ml(-1). Although filter paper degrading capability was low in single culture, significant synergetic cellulose degradation were detected in four groups of mixed cultures, their degradation rates were 23.5%, 26.3%, 19.4% and 24.5%, respectively. Study of morphological and physiological characters of five predominant isolates which possess high CMCase and had positive effect on synergetic cellulose degradation in mixed culture system showed that two of them were closely related to Bacillus pasteurii and Bacillus cereus, whereas the rest belong to the genus Halobacillus, Aeromicrobium and Brevibacterium, respectively. PMID:16474195

Lu, Wen-Jing; Wang, Hong-Tao; Yang, Shi-Jian; Wang, Zhi-Chao; Nie, Yong-Feng

2005-12-01

38

Improved stability of aerobic granules by selecting slow-growing nitrifying bacteria  

Microsoft Academic Search

This study investigated the feasibility of improving the stability of aerobic granules through selecting slow-growing nitrifying bacteria. For this purpose, four sequencing batch reactors were operated at different substrate N\\/COD ratios ranging from 5\\/100 to 30\\/100. Results showed that aerobic granules formed in all four reactors, and aerobic granulation was a gradual process evolving from the dispersed seed sludge to

Yu Liu; Shu-Fang Yang; Joo-Hwa Tay

2004-01-01

39

An innovative sewage sludge reduction by using a combined mesophilic anaerobic and thermophilic aerobic process with thermal-alkaline treatment and sludge recirculation.  

PubMed

Lab-scale High Efficiency Digestion (HED) systems containing a Mesophilic Anaerobic Reactor (MAR), Thermophilic Aerobic Reactor (TAR), liquid/solid separation unit, and thermal-alkaline treatment were developed to evaluate the efficiencies of sludge reduction and methane production. The HED process was divided into three phases to examine the influence of sludge pretreatment and pretreated sludge recirculation using TCOD and VSS reduction, COD solubilization, and methane production. The VSS removal with a solid/liquid separation unit, sludge recirculation, and thermal-alkaline treatment drastically increased up to 95% compared to the feed concentration. In addition, the results of COD solubilization and VSS/TSS showed that the solubilization of cells and organic matters by the thermal-alkaline treatment was highly increased, which was also consistent with the SEM images. In particular, the methane production rate increased 24-fold when the feed sludge and recirculated sludge were pretreated together. Collectively, the HED experiments performed with sludge recirculation and thermal-alkaline treatment demonstrated that the HED systems can be successfully employed for highly efficient sewage sludge reduction and methane gas production. PMID:23968913

Cho, Hyun Uk; Park, Sang Kyu; Ha, Jeong Hyub; Park, Jong Moon

2013-08-22

40

Evaluation of the petrifilm aerobic count plate for enumeration of aerobic marine bacteria from seawater and Caulerpa lentillifera.  

PubMed

The enumeration and evaluation of the activity of marine bacteria are important in the food industry. However, detection of marine bacteria in seawater or seafood has not been easy. The Petrifilm aerobic count plate (ACP) is a ready-to-use alternative to the traditional enumeration media used for bacteria associated with food. The purpose of this study was to evaluate the usefulness of a simple detection and enumeration method utilizing the Petrifilm ACP for enumeration of aerobic marine bacteria from seawater and an edible seaweed, Caulerpa lentillifera. The efficiency of enumeration of total aerobic marine bacteria on Petrifilm ACP was compared with that using the spread plate method on marine agar with 80 seawater and 64 C. lentillifera samples. With sterile seawater as the diluent, a close correlation was observed between the method utilizing Petrifilm ACP and that utilizing the conventional marine agar (r=0.98 for seawater and 0.91 for C. lentillifera). The Petrifilm ACP method was simpler and less time-consuming than the conventional method. These results indicate that Petrifilm ACP is a suitable alternative to conventional marine agar for enumeration of marine microorganisms in seawater and C. lentillifera samples. PMID:20819367

Kudaka, Jun; Horii, Toru; Tamanaha, Koji; Itokazu, Kiyomasa; Nakamura, Masaji; Taira, Katsuya; Nidaira, Minoru; Okano, Sho; Kitahara, Akio

2010-08-01

41

Acetylene degradation by new isolates of aerobic bacteria and comparison of acetylene hydratase enzymes  

Microsoft Academic Search

Aerobic acetylene-degrading bacteria were isolated from soil samples. Two isolates were assigned to the species Rhodococcus opacus, two others to Rhodococcus ruber and Gordona sp. They were compared with known strains of aerobic acetylene-, cyanide-, or nitrile-utilizing bacteria. The acetylene hydratases of R. opacus could be measured in cell-free extracts only in the presence of a strong reductant like titanium(III)

Bettina M Rosner; Frederick A Rainey; Reiner M Kroppenstedt; Bernhard Schink

1997-01-01

42

Modeling the effects of sucuk production technique on Listeria monocytogenes, aerobic bacteria and lactic acid bacteria during ripening and storage  

Microsoft Academic Search

The modeling of sucuk (Turkish dry-fermented sausage) production techniques on the survival of Listeria monocytogenes, aerobic bacteria (AB), lactic acid bacteria (LAB), and yeasts and molds (YM) during ripening and storage periods were studied. Effect of L. monocytogenes initially contaminated level (low, medium and high contaminated levels) with sucuk dough was also studied. Survival data were analyzed by non-linear regression

Osman Erkmen

2008-01-01

43

The catalytic mechanism for aerobic formation of methane by bacteria.  

PubMed

Methane is a potent greenhouse gas that is produced in significant quantities by aerobic marine organisms. These bacteria apparently catalyse the formation of methane through the cleavage of the highly unreactive carbon-phosphorus bond in methyl phosphonate (MPn), but the biological or terrestrial source of this compound is unclear. However, the ocean-dwelling bacterium Nitrosopumilus maritimus catalyses the biosynthesis of MPn from 2-hydroxyethyl phosphonate and the bacterial C-P lyase complex is known to convert MPn to methane. In addition to MPn, the bacterial C-P lyase complex catalyses C-P bond cleavage of many alkyl phosphonates when the environmental concentration of phosphate is low. PhnJ from the C-P lyase complex catalyses an unprecedented C-P bond cleavage reaction of ribose-1-phosphonate-5-phosphate to methane and ribose-1,2-cyclic-phosphate-5-phosphate. This reaction requires a redox-active [4Fe-4S]-cluster and S-adenosyl-L-methionine, which is reductively cleaved to L-methionine and 5'-deoxyadenosine. Here we show that PhnJ is a novel radical S-adenosyl-L-methionine enzyme that catalyses C-P bond cleavage through the initial formation of a 5'-deoxyadenosyl radical and two protein-based radicals localized at Gly?32 and Cys?272. During this transformation, the pro-R hydrogen from Gly?32 is transferred to the 5'-deoxyadenosyl radical to form 5'-deoxyadenosine and the pro-S hydrogen is transferred to the radical intermediate that ultimately generates methane. A comprehensive reaction mechanism is proposed for cleavage of the C-P bond by the C-P lyase complex that uses a covalent thiophosphate intermediate for methane and phosphate formation. PMID:23615610

Kamat, Siddhesh S; Williams, Howard J; Dangott, Lawrence J; Chakrabarti, Mrinmoy; Raushel, Frank M

2013-04-24

44

Conversion of cellulose to ethanol by mesophilic bacteria. Proposal for continuation of DOE Contract DE-AC02-81ER10878  

SciTech Connect

The project objective is to study the genetics of mesophilic anaerobic bacteria that ferment cellulose to ethanol. Bacteria used in this investigation are strains of Clostridium that (1) convert to ethanol not only cellulose, but also components of the hemicellulosic portion of biomass and (2) are relatively ethanol tolerant. Studies include plasmid analysis and fine-structure mapping of genes involved in the breakdown of cellulose to soluble sugars. These genes code for cellulase system enzymes such as endo-1,4-..beta..-glucanases, exo-1,4-..beta..-glucanases, ..beta..-glucosidases, and cellobiose phosphorylase. The research includes characterization of cellulase system enzymes present in ethanol-producing mesophilic clostridia as well as enzymes used by these bacteria in the breakdown of hemicellulosic components. This work will provide fundamental information on the genetics of cellulose-fermenting, ethanol-producing clostridia. This information will be valuable for understanding metabolic processes used by anaerobic bacteria to degrade cellulose, and for developing clostridial strains that can be used in the industrial conversion of biomass to ethanol. Finally, the research will elucidate basic aspects of the genetics of clostridia. At present, very little is known about the genetic systems of this large group of anaerobic bacteria. 5 refs.

Canale-Parola, E.

1986-04-15

45

Distinct distribution pattern of abundance and diversity of aerobic anoxygenic phototrophic bacteria in the global ocean  

Microsoft Academic Search

Summary Aerobic anoxygenic phototrophic bacteria (AAPB) are an important bacterial group with capability of har- vesting light energy, and appear to have a particular role in the ocean's carbon cycling. Yet the signifi- cance of AAPB relative to total bacteria (AAPB%) in different marine regimes are still controversial, and variation trend of genetic diversity of AAPB along environmental gradients remains

Nianzhi Jiao; Yao Zhang; Yonghui Zeng; Ning Hong; Rulong Liu; Feng Chen; Pinxian Wang

2007-01-01

46

Aerobic Anoxygenic Phototrophic Bacteria Attached to Particles in Turbid Waters of the Delaware and Chesapeake Estuaries  

Microsoft Academic Search

Aerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophs that, if abundant, may be biogeo- chemically important in the oceans. We used epifluorescence microscopy and quantitative PCR (qPCR) to examine the abundance of these bacteria by enumerating cells with bacteriochlorophyll a (bChl a) and the light-reaction center gene pufM, respectively. In the surface waters of the Delaware estuary, AAP bacteria were abundant,

Lisa A. Waidner; David L. Kirchman

2007-01-01

47

Interaction between human polymorphonuclear leukocytes (PMNL) and bacteria cultivated in aerobic and anaerobic conditions.  

PubMed

A study was performed on one strain of Escherichia coli (E. coli K12D22) and on one strain of Salmonella braenderup (S. braenderup S2828). The physico-chemical surface properties of the bacteria were strongly influenced by oxygen supply, viz. anaerobic growth conditions resulted in increasing of hydrophobicity. Interaction between human polymorphonuclear leukocytes and bacteria, measured as chemiluminescence, was more efficient when bacteria had been cultivated anaerobically than when cultivated aerobically. The results show the importance of the surface hydrophobicity of bacteria in interaction with PMNL, and the role of the growth conditions of bacteria in that process. PMID:3893034

Maluszynska, G M; Stendahl, O; Magnusson, K E

1985-04-01

48

Hygienic quality of commercial minced meat as indicated by aerobic micro-organisms and Coliform bacteria  

Microsoft Academic Search

The hygienic quality of commercial beef and beef-pork minced meat was examined using aerobic micro-organisms and Coliform\\u000a bacteria as indicator organisms. About 70% of the samples examined were of good quality and about 30% of tolerable quality.\\u000a Aerobic micro-organisms can be recommended as an initial means of monitoring the hygienic quality of minced meat, being better\\u000a for this purpose than

Anneli Skrökki

1997-01-01

49

Studying the Life Cycle of Aerobic Endospore-forming Bacteria in Soil  

Microsoft Academic Search

\\u000a Members of the genus Bacillus are commonly isolated from soils, with members of the Bacillus cereus group being prevalent. Our knowledge of the ecology of B. cereus and other aerobic spore-forming bacteria in soil is far from complete. We have developed an in terra approach to study soil-associated aerobes, using filter-sterilized soil extracted soluble organic matter (SESOM). B. cereus is

Volker S. Brözel; Yun Luo; Sebastien Vilain

50

Complete decomposition of biological waste sludge by thermophilic aerobic bacteria  

Microsoft Academic Search

Conventional activated sludge (AS) process is an economical and effective biooxidation process although a large amount of excess sludge is necessarily generated. We have developed a new zero- discharge AS process, in which no excess sludge is generated. It was formed by combining the conventional AS process with thermophilic aerobic sludge digester in which excess sludge is solubilized by thermophilic

Y. Sakai; T. Aoyagi; N. Shiota; A. Akashi; S. Hasegawa

2000-01-01

51

Distribution, diversity and ecology of aerobic CO-oxidizing bacteria  

Microsoft Academic Search

Numerous studies indicate that carbon monoxide (CO) participates in a broader range of processes than any other single molecule, ranging from subcellular to planetary scales. Despite its toxicity to many organisms, a diverse group of bacteria that span multiple phylogenetic lineages metabolize CO. These bacteria are globally distributed and include pathogens, plant symbionts and biogeochemically important lineages in soils and

Carolyn F. Weber; Gary M. King

2007-01-01

52

Developments in the Taxonomy of Aerobic, Endospore-forming Bacteria  

Microsoft Academic Search

\\u000a \\u000a Bacillus holds an important place in the history of bacteriology. With observations upon Bacillus subtilis and its spores Cohn discredited the theory of spontaneous generation, and with his demonstration of the life history of B. anthracis in 1876 Robert Koch proved the germ theory of disease and founded medical bacteriology. Later, Bacillus became defined as a genus of aerobic, endospore-forming

Niall A. Logan; Gillian Halket

53

Moulds, yeasts and aerobic plate counts in ginseng supplements  

Microsoft Academic Search

Forty six ginseng supplement samples including Siberian ginseng root, Chinese ginseng herb and root, and American ginseng root and extract were purchased from retail in the Washington, DC area and from Penn Herb Co. (Philadelphia, PA) and tested for mould and yeast (MY) contamination and the presence of aerobic mesophilic bacteria (APC). Results indicated that 100% of the Siberian ginseng

V. H. Tournas; Eugenia Katsoudas; E. J. Miracco

2006-01-01

54

Competition and coexistence of aerobic ammonium- and nitrite-oxidizing bacteria at low oxygen concentrations  

Microsoft Academic Search

In natural and man-made ecosystems nitrifying bacteria experience frequent exposure to oxygen-limited conditions and thus\\u000a have to compete for oxygen. In several reactor systems (retentostat, chemostat and sequencing batch reactors) it was possible\\u000a to establish co-cultures of aerobic ammonium- and nitrite-oxidizing bacteria at very low oxygen concentrations (2–8 ?M) provided\\u000a that ammonium was the limiting N compound. When ammonia was in

A. Olav Sliekers; Suzanne C. M. Haaijer; Marit H. Stafsnes; J. Gijs Kuenen; Mike S. M. Jetten

2005-01-01

55

The survival of multidrug-resistant bacteria in thermophilic and mesophilic anaerobic co-digestion of dairy manure and waste milk.  

PubMed

Anaerobic digestion is considered as a promising method to manage animal waste with antibiotic-resistant bacteria. Current research was conducted to investigate the survival of multidrug-resistant bacteria (MDRB) resistant to three groups of antibiotics: (i) cefazolin, neomycin, vancomycin, kanamycin (group 1); (ii) penicillin, oxytetracycline, ampicillin, streptomycin (group 2); and (iii) cefazolin, neomycin, vancomycin, kanamycin, penicillin, oxytetracycline, ampicillin, streptomycin (group 3), in anaerobic digestion of dairy manure and co-digestion of dairy manure and waste milk at 37°C and 55°C for 22 days, respectively. The population densities of three groups of MDRB on peptone, tryptone, yeast and glucose agar plates incubated at 30°C for 7 days before and after digestion showed 100% destruction in both digestates at thermophilic temperature. Overall reduction of more than 90% of three groups of MDRB was observed in mesophilic digestion with no significant differences (P?>?0.05) between manure and milk mixture. Co-digestion of dairy manure and waste milk always produced significantly (P?mesophilic digestion. The results demonstrate that thermophilic co-digestion of dairy manure and waste milk offers more benefits in terms of the environment and economy. PMID:23607603

Beneragama, Nilmini; Iwasaki, Masahiro; Lateef, Suraju A; Yamashiro, Takaki; Ihara, Ikko; Umetsu, Kazutaka

2012-12-17

56

Space agriculture for habitation on Mars with hyper-thermophilic aerobic composting bacteria  

Microsoft Academic Search

Manned Mars exploration, especially for extended periods of time, will require recycle of materials to support human life. Here, a conceptual design is developed for a Martian agricultural system driven by biologically regenerative functions. One of the core biotechnologies function is the use of hyper-thermophilic aerobic composting bacterial ecology. These thermophilic bacteria can play an important role in increasing the

S. Kanazawa; Y. Ishikawa; K. Tomita-Yokotani; H. Hashimoto; Y. Kitaya; M. Yamashita; M. Nagatomo; T. Oshima; H. Wada

2008-01-01

57

Aerobic biological treatment of olive mill wastewater by olive pulp bacteria  

Microsoft Academic Search

The capability of olive fruit bacteria to remove chemical oxygen demand (COD) and phenolic compounds from olive mill wastewater (OMW) using flasks and packed bed reactors was tested. Batch aerobic experiments were performed in flask reactors, with OMW at different dilutions (20%, 50%, and 100%). The maximum phenolic and dissolved COD removal reached up to 82–90% for the dilutions of

G. Tziotzios; S. Michailakis; D. V. Vayenas

2007-01-01

58

Combined heterotrophic nitrification and aerobic denitrification in Thiosphaera pantotropha and other bacteria  

Microsoft Academic Search

Reports of the simultaneous use of oxygen and denitrification by different species of bacteria have become more common over the past few years. Research with some strains (e.g. Thiosphaera pantotropha) has indicated that there might be a link between this ‘aerobic denitrification’ and a form of nitrification which requires rather than generates energy and is therefore known as heterotrophic nitrification.

Lesley A. Robertson; J. Gijs Kuenen

1990-01-01

59

A Method to Grow Obligately Aerobic Bacteria at Increased Hydrostatic Pressure.  

National Technical Information Service (NTIS)

Culture vessels made of gas-permeable silicone membranes are described in which obligately aerobic bacteria are grown under conditions where mechanical aeration is not possible. The growth of a strain of Pseudomonas putida at 1, 200, and 400 atm is used t...

L. R. Berger L. Q. Tam

1970-01-01

60

Concentrations of butyric acid bacteria spores in silage and relationships with aerobic deterioration  

Microsoft Academic Search

Germination and growth of spores of butyric acid bacteria (BAB) may cause severe defects in semihard cheeses. Silage is the main source of BAB spores in cheese milk. The objectives of the study were to deter- mine the significance of grass silages and corn silages assourcesofBABsporesandtoinvestigatetherelation- ships between high concentrations of BAB spores in corn silage and aerobic deterioration. In

M. M. M. Vissers; F. Driehuis; M. C. Te Giffel; P. De Jong; J. M. G. Lankveld

2007-01-01

61

On the natural selection and evolution of the aerobic phototrophic bacteria  

Microsoft Academic Search

This contribution gives a brief survey of the short history since the discovery of the aerobic phototrophic bacteria to focus on a general evolutionary scenario. Most of the citations are of reviews that have covered the earlier literature and to which the reader is directed at appropriate places in the following text. The data summarized in these reviews are supplemented

J. Thomas Beatty

2002-01-01

62

CHARACTERISTICS OF ALDEHYDE DEHYDROGENASES OF CERTAIN AEROBIC BACTERIA REPRESENTING HUMAN COLONIC FLORA  

Microsoft Academic Search

We have proposed the existence of a bacteriocolonic pathway for ethanol oxidation resulting in high intracolonic levels of toxic and carcinogenic acetaldehyde. This study was aimed at determining the ability of the aldehyde dehydrogenases (ALDH) of aerobic bacteria representing human colonic flora to metabolize intracolonically derived acetaldehyde. The apparent Michaelis constant (Km) values for acetaldehyde were determined in crude extracts

T. NOSOVA; K. JOKELAINEN; P. KAIHOVAARA; R. HEINE; H. JOUSIMIES-SOMER; M. SALASPURO

1998-01-01

63

Aerobic Anoxygenic Photosynthesis in Roseobacter Clade Bacteria from Diverse Marine Habitats  

Microsoft Academic Search

The marine Roseobacter clade comprises several genera of marine bacteria related to the uncultured SAR83 cluster, the second most abundant marine picoplankton lineage. Cultivated representatives of this clade are physiologically heterogeneous, and only some have the capability for aerobic anoxygenic photosynthesis, a process of potentially great ecological importance in the world's oceans. In an attempt to correlate phylogeny with ecology,

Martin Allgaier; Heike Uphoff; Andreas Felske; Irene Wagner-Dobler

2003-01-01

64

Velvet pad surface sampling of anaerobic and aerobic bacteria: an in vitro laboratory model  

Microsoft Academic Search

Velvet pads have been evaluated in an experimental, laboratory model, simulating intraoperative sampling of Staphylococcus epidermis, Escherichia coli and Bacteroides fragilis. After sampling, the pad was placed in a transport medium and kept in an anaerobic atmosphere, before being shaken and rinsed, followed by anaerobic and aerobic culture. This technique permitted quantitatively high recoveries of the test bacteria. Velvet pad

D Raahave; A Friis-Møller

1982-01-01

65

Fate of Chlortetracycline and Tylosin-Resistant Bacteria in an Aerobic Thermophilic Sequencing Batch Reactor Treating Swine Waste  

Microsoft Academic Search

Antibiotics have been added to animal feed for decades. Consequently, food animals and their wastes constitute a reservoir\\u000a of antibiotic-resistant bacteria. The objective of this work was to characterize the impact of an aerobic thermophilic biotreatment\\u000a on aerobic, antibiotic-resistant bacteria in swine waste. The proportion of tylosin- and chlortetracycline-resistant bacteria\\u000a grown at 25°C, 37°C, and 60°C decreased after treatment, but

Martin R. Chénier; Pierre Juteau

2009-01-01

66

[Resistance to chemotherapy of aerobic bacteria from nonspecific odontogenic infections].  

PubMed

Germs in patients suffering from nonspecific odontogenous infections described in a previous paper were analysed with regard to their resistance to chemotherapy (1964 to 1971). At the same time it was discovered that in the bacteria groups: staphyloccocus aureus, streptococci and pneumococci and enterobacteriaceae plus pseudomonas (344 strains) their sensitivity to penicillin, streptomycin, chloramphenicol, oxytetracyclin, erythromycin, polymyxin B and nifurantin varied in several and significant ways. Significant changes were established in the resistance of staphylococcus aureus to all the potentially effective antibiotics, while from 1969 to 1971 the strains with the least resistance appeared. In the 1970 to 1971 period strepto- and pneumococci showed insensitivity to penicillin and streptomycin more frequently than before. From 1969 to 1971 entero-bacteriaceae and pseudomonas also showed evidence of increasing loss of sensitivity to chloramphenicol and oxytetracyclin, whereas the frequency of strains resistant to polymyxin B and nifurantine diminished. The findings are being discussed. PMID:188271

Oehring, H; Schumann, D; Karl, P; Knappe, U; Gruhn, I

1976-01-01

67

Rapid High-Throughput Assessment of Aerobic Bacteria in Complex Samples by Fluorescence-Based Oxygen Respirometry  

Microsoft Academic Search

A simple method has been developed for the analysis of aerobic bacteria in complex samples such as broth and food homogenates. It employs commercial phosphorescent oxygen-sensitive probes to monitor oxygen consumption of samples containing bacteria using standard microtiter plates and fluorescence plate readers. As bacteria grow in aqueous medium, at certain points they begin to deplete dissolved oxygen, which is

Fiach C. O'Mahony; Dmitri B. Papkovsky

2006-01-01

68

[Screening and denitrification characteristics of a heterotrophic nitrification-aerobic denitrifier bacteria].  

PubMed

A heterotrophic nitrification-aerobic denitrifier bacteria CPZ24 was isolated form the livestock wastewater by way of the limiting dilution combined with the chromogenic medium screening methods. This bacterium was Gram positive, rod. The colonies of the strain were orange-red.It was identified as Rhodococuus pyridinivorans according to its morphological and physiological properties and the analysis of its 16S rDNA gene. Studied on its function of heterotrophic nitrification and aerobic denitrification,the results show that all NH4+ -N is removed and the removal rate of TN is 98.70% in heterotrophic nitrification; the removal rate of NO3- -N by this strain is 66.74% and the removal rate of TN is 64.27%. This high effective microorganisms with nitrogen removed is able to realize simultaneous nitrification and denitrification. It can perform the whole process of bacteria denitrification independently. PMID:20187396

Chen, Pei-zhen; Wang, Li-gang; Wang, Ying-chun; Li, Ji; Ding, Wei; Ren, Tian-zhi; Li, Shao-peng

2009-12-01

69

Aerobic Anoxygenic Phototrophic Bacteria in the Mid-Atlantic Bight and the North Pacific Gyre  

PubMed Central

The abundance of aerobic anoxygenic phototrophic (AAP) bacteria, cyanobacteria, and heterotrophs was examined in the Mid-Atlantic Bight and the central North Pacific Gyre using infrared fluorescence microscopy coupled with image analysis and flow cytometry. AAP bacteria comprised 5% to 16% of total prokaryotes in the Atlantic Ocean but only 5% or less in the Pacific Ocean. In the Atlantic, AAP bacterial abundance was as much as 2-fold higher than that of Prochlorococcus spp. and 10-fold higher than that of Synechococcus spp. In contrast, Prochlorococcus spp. outnumbered AAP bacteria 5- to 50-fold in the Pacific. In both oceans, subsurface abundance maxima occurred within the photic zone, and AAP bacteria were least abundant below the 1% light depth. The abundance of AAP bacteria rivaled some groups of strictly heterotrophic bacteria and was often higher than the abundance of known AAP bacterial genera (Erythrobacter and Roseobacter spp.). Concentrations of bacteriochlorophyll a (BChl a) were low (?1%) compared to those of chlorophyll a in the North Atlantic. Although the BChl a content of AAP bacteria per cell was typically 20- to 250-fold lower than the divinyl-chlorophyll a content of Prochlorococcus, the pigment content of AAP bacteria approached that of Prochlorococcus in shelf break water. Our results suggest that AAP bacteria can be quite abundant in some oceanic regimes and that their distribution in the water column is consistent with phototrophy.

Cottrell, Matthew T.; Mannino, Antonio; Kirchman, David L.

2006-01-01

70

Phylogenetic diversity and activity of aerobic heterotrophic bacteria from a hypersaline oil-polluted microbial mat  

Microsoft Academic Search

The diversity and function of aerobic heterotrophic bacteria (AHB) in cyanobacterial mats have been largely overlooked. We used culture-dependent and molecular techniques to explore the species diversity, degradative capacities and functional guilds of AHB in the photic layer (2mm) of an oil-polluted microbial mat from Saudi Arabia. Enrichment isolation was carried out at different salinities (5% and 12%) and temperatures

Raeid M. M. Abed; Burhanuddin Zein; Assad Al-Thukair; Dirk de Beer

2007-01-01

71

Aerobic anoxygenic phototrophic bacteria attached to particles in turbid waters of the Delaware and Chesapeake estuaries.  

PubMed

Aerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophs that, if abundant, may be biogeochemically important in the oceans. We used epifluorescence microscopy and quantitative PCR (qPCR) to examine the abundance of these bacteria by enumerating cells with bacteriochlorophyll a (bChl a) and the light-reaction center gene pufM, respectively. In the surface waters of the Delaware estuary, AAP bacteria were abundant, comprising up to 34% of prokaryotes, although the percentage varied greatly with location and season. On average, AAP bacteria made up 12% of the community as measured by microscopy and 17% by qPCR. In the surface waters of the Chesapeake, AAP bacteria were less abundant, averaging 6% of prokaryotes. AAP bacterial abundance was significantly correlated with light attenuation (r=0.50) and ammonium (r=0.42) and nitrate (r=0.71) concentrations. Often, bChl a-containing bacteria were mostly attached to particles (31 to 94% of total AAP bacteria), while usually 20% or less of total prokaryotes were associated with particles. Of the cells containing pufM, up to 87% were associated with particles, but the overall average of particle-attached cells was 15%. These data suggest that AAP bacteria are particularly competitive in these two estuaries, in part due to attachment to particles. PMID:17468276

Waidner, Lisa A; Kirchman, David L

2007-04-27

72

Numbers, diversity, and morphological characteristics of aerobic, chemoheterotrophic bacteria in deep subsurface sediments from a site in South Carolina  

Microsoft Academic Search

The aerobic, chemoheterotrophic bacteria indigenous to deep aquifers and other subsurface sediments (depths to 265 m) at a site in South Carolina were characterized by direct microscopy, enumeration of viable cells, analysis of colony morphologies on plates, and analysis of cell morphologies of isolated strains. Substantial numbers of viable bacteria (1010\\/g) were present in all transmissive, aquifer sediments, and their

David L. Balkwill

1989-01-01

73

Effect of radiation dose on the recovery of aerobic and anaerobic bacteria from mice  

SciTech Connect

The presence of aerobic and anaerobic bacteria in the blood, spleen, and liver was investigated in mice that were exposed to 7, 8, 9, or 10 Gy /sup 60/Co radiation. Microorganisms were detected more often in animals exposed to higher doses of radiation. The number of mice that were culture positive and the number of isolates in one site increased with increasing dose. Bacteria were recovered in mice killed at various times after radiation, in 3 of 100 mice exposed to 7 Gy, in 13 of 100 irradiated with 8 Gy, in 23 of 90 exposed to 9 Gy, and in 34 of 87 irradiated with 10 Gy. The predominant organisms recovered were Escherichia coli, anerobic Gram-positive cocci, Proteus mirabilis, Staphylococcus aureus, and Bacteroides spp. Escherichia coli and anaerobes were more often isolated in animals exposed to 10 Gy, while S. aureus was more often recovered in those irradiated with 9 Gy. These data demonstrate a relationship between the dose of radiation and the rate of infection due to entire aerobic and anaerobic bacteria. Reprints.

Brook, I.; Walker, R.I.; MacVittie, T.J.

1986-01-01

74

Phylogenetic and Kinetic Diversity of Aerobic Vinyl Chloride-Assimilating Bacteria from Contaminated Sites  

PubMed Central

Aerobic bacteria that grow on vinyl chloride (VC) have been isolated previously, but their diversity and distribution are largely unknown. It is also unclear whether such bacteria contribute to the natural attenuation of VC at chlorinated-ethene-contaminated sites. We detected aerobic VC biodegradation in 23 of 37 microcosms and enrichments inoculated with samples from various sites. Twelve different bacteria (11 Mycobacterium strains and 1 Nocardioides strain) capable of growth on VC as the sole carbon source were isolated, and 5 representative strains were examined further. All the isolates grew on ethene in addition to VC and contained VC-inducible ethene monooxygenase activity. The Mycobacterium strains (JS60, JS61, JS616, and JS617) all had similar growth yields (5.4 to 6.6 g of protein/mol), maximum specific growth rates (0.17 to 0.23 day?1), and maximum specific substrate utilization rates (9 to 16 nmol/min/mg of protein) with VC. The Nocardioides strain (JS614) had a higher growth yield (10.3 g of protein/mol), growth rate (0.71 day?1), and substrate utilization rate (43 nmol/min/mg of protein) with VC but was much more sensitive to VC starvation. Half-velocity constant (Ks) values for VC were between 0.5 and 3.2 ?M, while Ks values for oxygen ranged from 0.03 to 0.3 mg/liter. Our results indicate that aerobic VC-degrading microorganisms (predominantly Mycobacterium strains) are widely distributed at sites contaminated with chlorinated solvents and are likely to be responsible for the natural attenuation of VC.

Coleman, Nicholas V.; Mattes, Timothy E.; Gossett, James M.; Spain, Jim C.

2002-01-01

75

Quantification of Syntrophic Fatty Acid-?-Oxidizing Bacteria in a Mesophilic Biogas Reactor by Oligonucleotide Probe Hybridization  

PubMed Central

Small-subunit rRNA sequences were obtained for two saturated fatty acid-?-oxidizing syntrophic bacteria, Syntrophomonas sapovorans and Syntrophomonas wolfei LYB, and sequence analysis confirmed their classification as members of the family Syntrophomonadaceae. S. wolfei LYB was closely related to S. wolfei subsp. wolfei, but S. sapovorans did not cluster with the other members of the genus Syntrophomonas. Five oligonucleotide probes targeting the small-subunit rRNA of different groups within the family Syntrophomonadaceae, which contains all currently known saturated fatty acid-?-oxidizing syntrophic bacteria, were developed and characterized. The probes were designed to be specific at the family, genus, and species levels and were characterized by temperature-of-dissociation and specificity studies. To demonstrate the usefulness of the probes for the detection and quantification of saturated fatty acid-?-oxidizing syntrophic bacteria in methanogenic environments, the microbial community structure of a sample from a full-scale biogas plant was determined. Hybridization results with probes for syntrophic bacteria and methanogens were compared to specific methanogenic activities and microbial numbers determined with most-probable-number estimates. Most of the methanogenic rRNA was comprised of Methanomicrobiales rRNA, suggesting that members of this order served as the main hydrogen-utilizing microorganisms. Between 0.2 and 1% of the rRNA was attributed to the Syntrophomonadaceae, of which the majority was accounted for by the genus Syntrophomonas.

Hansen, Kaare H.; Ahring, Birgitte K.; Raskin, Lutgarde

1999-01-01

76

Quantification of syntrophic fatty acid-{beta}-oxidizing bacteria in a mesophilic biogas reactor by oligonucleotide probe hybridization  

SciTech Connect

Small-subunit rRNA sequences were obtained for two saturated fatty acid-{beta}-oxidizing syntrophic bacteria, Syntrophomonas sapovorans and Syntrophomonas wolfei LYB, and sequence analysis confirmed their classification as members of the family Syntrophomonadaceae. S.wolfei LYB was closely related to S.wolfei subsp. solfei, but S. sapovorans did not cluster with the other members of the genus Syntrophomonas. Five oligonucleotide probes targeting the small-subunit rRNA of different groups within the family Syntrophomonadaceae, which contains all currently known saturated fatty acid-{beta}-oxidizing syntrophic bacteria, were developed and characterized. The probes were designed to be specific at the family, genus, and species levels and were characterized by temperature-of-dissociation and specificity studies. To demonstrate the usefulness of the probes for the detection and quantification of saturated fatty acid-{beta}-oxidizing syntrophic bacteria in methanogenic environments, the microbial community structure of a sample from a full-scale biogas plant was determined. Hybridization results with probes for syntrophic bacteria and methanogens were compared to specific methanogenic activities and microbial numbers determined with most-probable-number estimates. Most of the methanogenic rRNA was comprised of Methanomicrobiales rRNA, suggesting that members of this order served as the main hydrogen-utilizing microorganisms. Between 0.2 and 1% of the rRNA was attributed to the Syntrophomonadaceae, or which the majority was accounted for by the genus Syntrophomonas.

Hansen, K.H.; Ahring, B.K.; Raskin, L.

1999-11-01

77

Population of aerobic heterotrophic nitrogen-fixing bacteria associated with wetland and dryland rice  

SciTech Connect

Nitrogen-fixing activity and populations of nitrogen-fixing bacteria associated with two varieties of rice grown in dryland and wetland conditions were measured at various growth stages during the dry season. Acetylene reduction activities were measured both in the field and for the hydroponically grown rice, which was transferred from the field to water culture 1 day before assay. The activities measured by both methods were higher in wetland than in dryland rice. The population of nitrogen-fixing heterotrophic bacteria associated with rhizosphere soil, root, and basal shoots was determined by the most probable number method with semisolid glucose-yeast extract and semisolid malate-yeast extract media. The number of nitrogen-fixing bacteria was higher in wetland conditions than in dryland conditions. The difference between two conditions was most pronounced in the population associated with the basal shoot. The glucose medium gave higher counts than did the malate medium. Colonies were picked from tryptic soy agar plates, and their nitrogen-fixing activity was tested on a semisolid glucose-yeast extract medium. The incidence of nitrogen-fixing bacteria among aerobic heterotrophic bacteria in association with rhizosphere soil, root, and basal shoots was much lower in dryland rice than in wetland rice. (Refs. 11).

Barraquio, W.L.; De Guzman, M.R.; Barrion, M.; Watanahe, I.

1982-01-01

78

Diversity of aerobic and anaerobic ammonia-oxidizing bacteria in marine sponges.  

PubMed

Aerobic ammonia-oxidizing bacteria (AAOB) are known to have an important function in the marine nitrogen cycle. Anaerobic ammonium oxidation (anammox) carried out by some members of Planctomycetales is also an important process in marine ecosystems. Ammonia-monooxygenase gene (amoA) fragments were amplified to investigate the potential for nitrification and the diversity of the AAOB in two marine sponges Ircinia strobilina and Mycale laxissima. All of the AmoA sequences obtained from the two sponges clustered with the AmoA sequences of the Betaproteobacteria Nitrosospira spp. To investigate the anaerobic ammonia-oxidizing bacteria (AnAOB) in sponges, 16S rRNA gene fragments of Planctomycetales and anammox bacteria were also amplified with specific primers, and clone libraries were constructed. The Planctomycetales diversity detected in the two sponges was different. The Planctomycetales community in M. laxissima was affiliated with Pirellula, Planctomyces and anammox bacteria, while all of the I. strobilina Planctomycetales clones were solely affiliated with the candidate phylum 'Poribacteria'. Interestingly, sequences related to anammox genera were recovered only from M. laxissima. This is the first report of anammox bacteria in marine sponges. It is intriguing to find AAOB and AnAOB in M. laxissima, but the nature of their interaction with the sponge host and with each other remains unclear. This work further supports the potential of sponge-associated microorganisms for nitrification and sheds light on anammox as a new aspect of the nitrogen cycle in marine sponges. PMID:19617876

Mohamed, Naglaa M; Saito, Keiko; Tal, Yossi; Hill, Russell T

2009-07-16

79

Purple Sulfur Bacteria Control the Growth of Aerobic Heterotrophic Bacterioplankton in a Meromictic Salt Lake  

PubMed Central

In meromictic Mahoney Lake, British Columbia, Canada, the heterotrophic bacterial production in the mixolimnion exceeded concomitant primary production by a factor of 7. Bacterial growth rates were correlated neither to primary production nor to the amount of chlorophyll a. Both results indicate an uncoupling of bacteria and phytoplankton. In the chemocline of the lake, an extremely dense population of the purple sulfur bacterium Amoebobacter purpureus is present year round. We investigated whether anoxygenic phototrophs are significant for the growth of aerobic bacterioplankton in the overlaying water. Bacterial growth rates in the mixolimnion were limited by inorganic phosphorus or nitrogen most of the time, and the biomass of heterotrophic bacteria did not increase until, in autumn, 86% of the cells of A. purpureus appeared in the mixolimnion because of their reduced buoyant density. The increase in heterotrophic bacterial biomass, soluble phosphorus concentrations below the detection limit, and an extraordinarily high activity of alkaline phosphatase in the mixolimnion indicate a rapid liberation of organically bound phosphorus from A. purpureus cells accompanied by a simultaneous incorporation into heterotrophic bacterioplankton. High concentrations of allochthonously derived dissolved organic carbon (mean, 60 mg of C(middot)liter(sup-1)) were measured in the lake water. In Mahoney Lake, liberation of phosphorus from upwelling purple sulfur bacteria and degradation of allochthonous dissolved organic carbon as an additional carbon source render heterotrophic bacterial production largely independent of the photosynthesis of phytoplankton. A recycling of inorganic nutrients via phototrophic bacteria also appears to be relevant in other lakes with anoxic bottom waters.

Overmann, J.; Beatty, J. T.; Hall, K. J.

1996-01-01

80

[Bioaugmentation for shortcut nitrification in SBR treating for sewage containing sea water by nitrification-aerobic denitrification bacteria].  

PubMed

The feasibility of heterotrophic nitrification-aerobic denitrification bacteria applied in shortcut nitrification system was studied. Four heterotrophic nitrification-aerobic denitrification strains mixed with halotolerant activated sludge was added into SBR in order to test their bioaugmentation ability for shortcut nitrification system, which was treating for sewage containing sea water, and the difference between bioaugmentation system and original system was compared. The results showed that the maximum accumulation of NO2(-) -N in bioaugmentation system was 34.92% lower than that in original system, and the time of maximum accumulation of NO2(-) -N was 2 hours earlier than that in original system. The TN and COD was continuously decreasing in the later phase of nitrification in bioaugmentation system, and finally the removal rate of TN and COD were 15.24% and 5.39% higher than that in original system respectively, as well as the removal rate of NH4(+) -N and the nitrosation rate were 6.85% and 14.47% higher than that in original system. And the pH was 0.46 higher than that in original system, whereas the ORP was 25.84 mV lower. It was considered that the function of heterotrophic nitrification-aerobic denitrification bacteria should strengthen the performance of bioaugmentation system. When the seawater content raised to 70%, the stability of bioaugmentation system was better than that in original system, and the current that transforming shortcut nitrification to complete nitrification was restrained by heterotrophic nitrification-aerobic denitrification bacteria effectively. The number of heterotrophic nitrification-aerobic denitrification bacteria was changed when bioaugmentation system and original system ran in different phase and the bacteria had a great loss with the discharge of activated sludge. These results may provide a theoretical reference about the feasibility that the heterotrophic nitrification-aerobic denitrification bacteria applied in shortcut nitrification system. PMID:21229749

Qu, Yang; Zhang, Pei-Yu; Yu, De-Shuang; Guo, Sha-Sha; Yang, Rui-Xia

2010-10-01

81

EVALUATION OF THE BIOSYS OPTICAL METHOD FOR RAPIDLY ENUMERATING POPULATIONS OF AEROBIC BACTERIA, COLIFORMS, AND ESCHERICHIA COLI FROM BROILER CHICKEN CARCASSES  

Microsoft Academic Search

SUMMARY A study was conducted to determine if a rapid optical method could be used to enumerate total aerobic bacteria, coliforms, and Escherichia coli from broiler chicken carcasses. The BioSys optical method was compared with standard methods for enumerating bacteria. For chicken carcasses, the correlation coefficients for the regression lines comparing aerobic plate counts, coliform counts, and E. coli most

S. M. RUSSELL

82

Analyses of spatial distributions of sulfate-reducing bacteria and their activity in aerobic wastewater biofilms  

SciTech Connect

The vertical distribution of sulfate-reducing bacteria (SRB) in aerobic wastewater biofilms grown on rotating disk reactors was investigated by fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes. To correlate the vertical distribution of SRB populations with their activity, the microprofiles of O{sub 2}, H{sub 2}S, NO{sub 2}{minus}, NH{sub 2}{sup +}, and pH were measured with microelectrodes. In addition, a cross-evaluation of the FISH and microelectrode analyses was performed by comparing them with culture-based approaches and biogeochemical measurements. In situ hybridization revealed that a relatively high abundance of the probe SRB385-stained cells were evenly distributed throughout the biofilm, even in the toxic surface. The probe SRB660-stained Desulfobulbus spp. were found to be numerically important members of SRB populations. The result of microelectrode measurements showed that a high sulfate-reducing activity was found in a narrow anaerobic zone located about 150 to 300 {micro}m below the biofilm surface and above which an intensive sulfide oxidation zone was found. The biogeochemical measurements showed that elemental sulfur (S{degree}) was an important intermediate of the sulfide reoxidation in such thin wastewater biofilms, which accounted for about 75% of the total S pool in the biofilm. The contribution of an internal Fe-sulfur cycle to the overall sulfur cycle in aerobic wastewater biofilms was insignificant (less than 1%) due to the relatively high sulfate reduction rate.

Okabe, Satoshi; Itoh, Tsukasa; Satoh, Hisashi; Watanabe, Yoshimasa

1999-11-01

83

Diversity and phylogeny of the ectoine biosynthesis genes in aerobic, moderately halophilic methylotrophic bacteria.  

PubMed

The genes of ectoine biosynthesis pathway were identified in six species of aerobic, slightly halophilic bacteria utilizing methane, methanol or methylamine. Two types of ectoine gene cluster organization were revealed in the methylotrophs. The gene cluster ectABC coding for diaminobutyric acid (DABA) acetyltransferase (EctA), DABA aminotransferase (EctB) and ectoine synthase (EctC) was found in methanotrophs Methylobacter marinus 7C and Methylomicrobium kenyense AMO1(T). In methanotroph Methylomicrobium alcaliphilum ML1, methanol-utilizers Methylophaga thalassica 33146(T) , Methylophaga alcalica M8 and methylamine-utilizer Methylarcula marina h1(T), the genes forming the ectABC-ask operon are preceded by ectR, encoding a putative transcriptional regulatory protein EctR. Phylogenetic relationships of the Ect proteins do not correlate with phylogenetic affiliation of the strains, thus implying that the ability of methylotrophs to produce ectoine is most likely the result of a horizontal transfer event. PMID:21971967

Reshetnikov, Alexander S; Khmelenina, Valentina N; Mustakhimov, Ildar I; Kalyuzhnaya, Marina; Lidstrom, Mary; Trotsenko, Yuri A

2011-10-05

84

Effect of linear alkylbenzene sulfonates on the growth of aerobic heterotrophic cultivable bacteria isolated from an agricultural soil  

Microsoft Academic Search

An enrichment culture technique was used to isolate soil bacteria capable of growing in the presence of two different concentrations\\u000a of linear alkylbenzene sulfonates (LAS) (10 and 500 ?g ml?1). Nine bacterial strains, representatives of the major colony types of aerobic heterotrophic cultivable bacteria in the enriched\\u000a samples, were isolated and subsequently identified by PCR-amplification and partial sequencing of the 16S rRNA

María del Mar Sánchez-Peinado; Jesús González-López; Belén Rodelas; Vanesa Galera; Clementina Pozo; María Victoria Martínez-Toledo

2008-01-01

85

Exploring Diversity of Cultivable Aerobic Endospore-forming Bacteria: From Pasteurization to Procedures Without Heat-Shock Selection  

Microsoft Academic Search

\\u000a The assessment of the diversity of populations with low abundances in soil, as are most of the aerobic endospore-forming bacteria,\\u000a is a real challenge in modern studies of microbial ecology. Besides the culture-independent approaches reported in De Vos,\\u000a Studying the bacterial diversity of the soil by culture-independent approaches. In: Logan NA (ed) Endospore forming soil bacteria\\u000a (Soil Biology 27). Springer,

O. Berge; P. Mavingui; T. Heulin

86

Discrimination of Aerobic Endospore-forming Bacteria via Electrospray-Ionization Mass Spectrometry of Whole Cell Suspensions  

Microsoft Academic Search

Direct injection electrospray ionization mass spectrometry (ESI-MS) without prior analyte separation was investigated for the analysis of whole cell suspensions of bacteria. Thirty-six strains of aerobic endospore-forming bacteria, consisting of six Bacillus species and one Brevibacillus species, were studied. ESI was performed in the positive ion mode on the bacterial suspensions. Several peaks in the range of 250-1500 m\\/z were

Seetharaman Vaidyanathan; Jem J. Rowland; Douglas B. Kell; Royston Goodacre

2001-01-01

87

Impact of an Aerobic Thermophilic Sequencing Batch Reactor on Antibiotic-Resistant Anaerobic Bacteria in Swine Waste  

Microsoft Academic Search

The introduction of antibiotics to animal feed has contributed to the selection of antibiotic-resistant bacteria in concentrated\\u000a animal feeding operations. The aim of this work was to characterize the impact of an aerobic thermophilic biotreatment on\\u000a anaerobic antibiotic-resistant bacteria in swine waste. Despite 162- to 6,166-fold reduction in antibiotic-resistant populations\\u000a enumerated in the swine waste at 25°C and 37°C, resistant

Martin R. Chénier; Pierre Juteau

2009-01-01

88

Numerical Taxonomy of Aerobic, Gram-negative Bacteria associated with Oysters and Surrounding Seawater of the Mediterranean Coast  

Microsoft Academic Search

A numerical taxonomic study was performed on 245 strains of heterotrophic, aerobic, marine bacteria, plus 26 reference strains. The isolates were obtained from oysters and seawater sampled monthly over one year, by direct plating on Marine Agar. The strains were characterised by 93 morphological, biochemical, physiological and nutritional tests. Clustering yielded 46 phena at 0.60 S level (SJ coefficient). Some

Margarita Ortigosa; Esperanza Garay; María-Jesús Pujalte

1995-01-01

89

Comparison between rinse and crush-and-rub sampling for aerobic bacteria recovery from broiler hatching eggs after sanitization  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study compared surface and deep eggshell aerobic bacteria recovered by rinse and crush-and-rub sampling methods for commercial hatching eggs after treatment with sanitizers. Eggs were arranged into 5 treatments consisting of No-treatment, Water, and three sanitizers. Sanitizers were Hydrogen ...

90

Comparison between Rinse and Crush-and-Rub Sampling for Aerobic Bacteria Recovery from Hatching Eggs after Sanitization  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study compared surface and deep eggshell aerobic bacteria recovered by rinse and crush-and-rub sampling methods for commercial hatching eggs after treatments with sanitizers. Eggs were arranged into 5 treatments consisting of three sanitizers, Water, and No-treatment. Sanitizers were Hydrogen...

91

Plutonium Oxidation State Distribution under Aerobic and Anaerobic Subsurface Conditions for Metal-Reducing Bacteria  

NASA Astrophysics Data System (ADS)

The fate and potential mobility of plutonium in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium is the near-surface contaminant of concern at several DOE sites and continues to be the contaminant of concern for the permanent disposal of nuclear waste. The mobility of plutonium is highly dependent on its redox distribution at its contamination source and along its potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity. The redox distribution of plutonium in the presence of facultative metal reducing bacteria (specifically Shewanella and Geobacter species) was established in a concurrent experimental and modeling study under aerobic and anaerobic conditions. Pu(VI), although relatively soluble under oxidizing conditions at near-neutral pH, does not persist under a wide range of the oxic and anoxic conditions investigated in microbiologically active systems. Pu(V) complexes, which exhibit high chemical toxicity towards microorganisms, are relatively stable under oxic conditions but are reduced by metal reducing bacteria under anaerobic conditions. These facultative metal-reducing bacteria led to the rapid reduction of higher valent plutonium to form Pu(III/IV) species depending on nature of the starting plutonium species and chelating agents present in solution. Redox cycling of these lower oxidation states is likely a critical step in the formation of pseudo colloids that may lead to long-range subsurface transport. The CCBATCH biogeochemical model is used to explain the redox mechanisms and final speciation of the plutonium oxidation state distributions observed. These results for microbiologically active systems are interpreted in the context of their importance in defining the overall migration of plutonium in the subsurface.

Reed, D. T.; Swanson, J.; Khaing, H.; Deo, R.; Rittmann, B.

2009-12-01

92

Space agriculture for habitation on Mars with hyper-thermophilic aerobic composting bacteria  

NASA Astrophysics Data System (ADS)

Manned Mars exploration, especially for extended periods of time, will require recycle of materials to support human life. Here, a conceptual design is developed for a Martian agricultural system driven by biologically regenerative functions. One of the core biotechnologies function is the use of hyper-thermophilic aerobic composting bacterial ecology. These thermophilic bacteria can play an important role in increasing the effectiveness of the processing of human metabolic waste and inedible biomass and of converting them to fertilizer for the cultivation of plants. This microbial technology has been already well established for the purpose of processing sewage and waste materials for small local communities in Japan. One of the characteristics of the technology is that the metabolic heat release that occurs during bacterial fermentation raises the processing temperature sufficiently high at 80 100 °C to support hyper-thermophilic bacteria. Such a hyper-thermophilic system is found to have great capability of decomposing wastes including even their normally recalcitrant components, in a reasonably short period of time and of providing a better quality of fertilizer as an end-product. High quality compost has been shown to be a key element in creating a healthy regenerative food production system. In ground-based studies, the soil microbial ecology after the addition of high quality compost was shown to improve plant growth and promote a healthy symbiosis of arbuscular mycorrhizal fungi. Another advantage of such high processing temperature is the ability to sterilize the pathogenic organisms through the fermentation process and thus to secure the hygienic safety of the system. Plant cultivation is one of the other major systems. It should fully utilize solar energy received on the Martian surface for supplying energy for photosynthesis. Subsurface water and atmospheric carbon dioxide mined on Mars should be also used in the plant cultivation system. Oxygen and food production for human thus rely on local Martian resources. A tree growing subsystem will also give an interesting feature to Martian agriculture. In addition to producing excess oxygen, trees’ rigid body will provide structural material, which can be used for habitat construction. The combination of hyper-thermophilic aerobic composting, plant cultivation, and tree growing with utilizing in-situ natural local resources available on Mars can provide important elements which can enable space agriculture on Mars.

Space Agriculture Task Force; Ishikawa, Y.; Tomita-Yokotani, K.; Hashimoto, H.; Kitaya, Y.; Yamashita, M.; Nagatomo, M.; Oshima, T.; Wada, H.

93

Production of Wax Esters during Aerobic Growth of Marine Bacteria on Isoprenoid Compounds  

PubMed Central

This paper describes the production of isoprenoid wax esters during the aerobic degradation of 6,10,14-trimethylpentadecan-2-one and phytol by four bacteria (Acinetobacter sp. strain PHY9, Pseudomonas nautica [IP85/617], Marinobacter sp. strain CAB [DSMZ 11874], and Marinobacter hydrocarbonoclasticus [ATCC 49840]) isolated from the marine environment. Different pathways are proposed to explain the formation of these compounds. In the case of 6,10,14-trimethylpentadecan-2-one, these esters result from the condensation of some acidic and alcoholic metabolites produced during the biodegradation, while phytol constitutes the alcohol moiety of most of the esters produced during growth on this isoprenoid alcohol. The amount of these esters formed increased considerably in N-limited cultures, in which the ammonium concentration corresponds to conditions often found in marine sediments. This suggests that the bacterial formation of isoprenoid wax esters might be favored in such environments. Although conflicting evidence exists regarding the stability of these esters in sediments, it seems likely that, under some conditions, bacterial esterification can enhance the preservation potential of labile compounds such as phytol.

Rontani, Jean-Francois; Bonin, Patricia C.; Volkman, John K.

1999-01-01

94

Effects of Inoculants Containing Propionic Acid Bacteria on Fermentation and Aerobic Stability of Corn Silage[1] and [2  

Microsoft Academic Search

The effects of microbial inoculants containing propionic acid bacteria on fermentation and aerobic stability of corn silage were examined. Whole-plant corn was ensiled for 3, 21, and 90 d in 5- to 7-kg capacity polyethylene bags, and six treatments were compared: no additive, Pediococcus cerevisiae at 3 × 105 cfu\\/g of fresh forage plus Lactobacillus planta- rum at 1.5 ×

G. E. Higginbotham; S. C. Mueller; K. K. Bolsen; E. J. DePeters

1998-01-01

95

Detection and Quantification of Bacteria Involved in Aerobic and Anaerobic Ammonium Oxidation in an Ammonium-Contaminated Aquifer  

Microsoft Academic Search

The aerobic and anaerobic ammonium-oxidizing bacterial guilds were studied from two multilevel samplers in an ammonium-contaminated aquifer in the UK. By end point polymerase chain reaction (PCR), the presence of betaproteobacterial ammonium-oxidizing bacteria and anaerobic ammonium-oxidizing (anammox) planctomycetes was demonstrated. The sequences of cloned anammox-specific PCR fragments had close relationships with known anammox strains. Real-time PCR was subsequently used to

Theo H. M. Smits; Arne Hüttmann; David N. Lerner; Christof Holliger

2009-01-01

96

Survival of Staphylococcus aureus and aerobic bacteria in sucuks made from starter culture and Thymbra spicata during manufacturing and storage  

Microsoft Academic Search

Sucuk (a kind of dry-fermented Turkish sausage) dough was inoculated with Staphylococcus aureus at a level of 3.74 log colony forming unit (cfu) g?1 and manufactured in the presence of spices and addition of lactic acid bacteria (LAB) and with and without essential oil of Thymbra spicata. All samples were analyzed for S. aureus, aerobic plate count (APC), LAB and

Osman Erkmen

2009-01-01

97

Effects of combining Lactobacillus buchneri 40788 with various lactic acid bacteria on the fermentation and aerobic stability of corn silage  

Microsoft Academic Search

The objective was to compare the effectiveness of combining Lactobacillus buchneri 40788 with three lactic acid bacteria on the fermentation, aerobic stability and nutritive value of corn silage. Freshly chopped whole plant corn was untreated or treated with L. buchneri 40788 paired with Lactobacillus plantarum, Pediococcus acidilactici, or Pediococcus pentosaceus. L. buchneri was added to achieve 4×105CFU\\/g of fresh forage

Lindsey J. Reich; Limin Kung Jr.

2010-01-01

98

Natural Transformation in Mesophilic and Thermophilic Bacteria: Identification and Characterization of Novel, Closely Related Competence Genes in Acinetobacter sp. Strain BD413 and Thermus thermophilus HB27  

Microsoft Academic Search

The mesophile Acinetobacter sp. strain BD413 and the extreme thermophile Thermus thermophilus HB27 display high frequencies of natural transformation. In this study we identified and characterized a novel competence gene in Acinetobacter sp. strain BD413, comA, whose product displays significant similarities to the competence proteins ComA and ComEC in Neisseria and Bacillus species. Transcription of comA correlated with growth phase-dependent

ALEXANDRA FRIEDRICH; THOMAS HARTSCH; BEATE AVERHOFF

2001-01-01

99

Induction of bphA, Encoding Biphenyl Dioxygenase, in Two Polychlorinated Biphenyl-Degrading Bacteria, Psychrotolerant Pseudomonas Strain Cam1 and Mesophilic Burkholderia Strain LB400  

Microsoft Academic Search

We investigated induction of biphenyl dioxygenase in the psychrotolerant polychlorinated biphenyl (PCB) degrader Pseudomonas strain Cam-1 and in the mesophilic PCB degrader Burkholderia strain LB400. Using a counterselectable gene replacement vector, we inserted a lacZ-Gmr fusion cassette between chromosomal genes encoding the large subunit (bphA) and small subunit (bphE) of biphenyl dioxygenase in Cam-1 and LB400, generating Cam-10 and LB400-1,

EMMA R. MASTER; WILLIAM W. MOHN

2001-01-01

100

Comparison between rinse and crush-and-rub sampling for aerobic bacteria recovery from broiler hatching eggs after sanitization.  

PubMed

This study compared surface and deep eggshell aerobic bacteria recovered by the rinse and crush-and-rub sampling methods for commercial hatching eggs after treatment with sanitizers. Eggs were arranged into 5 treatments consisting of no treatment, water, and 3 sanitizers. The sanitizers were H(2)O(2), phenol, and Q(4)B (a compound chemical containing 4 quaternary ammoniums and 1 biguanide moiety). Eggs were sprayed according to treatment and allowed to dry for 1 h before sampling. To collect samples for the eggshell rinse, each egg was massaged in a plastic bag with 20 mL of saline. Eggshells were then aseptically opened and their contents were discarded before being individually crushed into 50-mL centrifuge tubes containing 20 mL of saline. Aerobic bacteria were enumerated on Petrifilm after 48 h of incubation at 37°C. Aerobic bacteria recovered (log(10) cfu/mL) from the eggshell rinse were highest and similar for the no-treatment (4.0) and water (3.7) groups, lower for the phenol (3.2) and H(2)O(2) (3.1) groups, and lowest for the Q(4)B (2.4) group. Aerobic bacteria levels with the crush-and-rub method were similar for the no-treatment (2.5) and water (2.3) groups, lower for the phenol (1.6) group, intermediate for the H(2)O(2) (1.2) group, and lowest for the Q(4)B (0.9) group. The overall correlation between the rinse and crush-and-rub sampling methods for individual egg aerobic bacteria counts was r = 0.71. The correlation within each treatment revealed the following r values: no treatment, 0.55; water, 0.72; H(2)O(2), 0.67; phenol, 0.73; and Q(4)B, 0.38. A second experiment was designed to further examine the lower aerobic bacterial levels recovered by the crush-and-rub method (for previously rinsed eggs) than the levels recovered in the initial eggshell rinse sample. Eggs were either rinsed and then crushed and rubbed, or they were only crushed and rubbed without a prior rinse. Results confirmed a significant decrease (1.5 log(10) cfu/mL) in bacteria levels between the initial rinse (4.4) and the subsequent crush and rub (2.9) for the same eggshell. For the crush-and-rub eggs with no previous rinsing, the bacteria recovery level (3.9) was not significantly different from levels for the rinse method. Therefore, either the rinse or crush-and-rub sampling methods can be used to recover similar levels of eggshell aerobic bacteria. PMID:21673179

Spickler, J L; Buhr, R J; Cox, N A; Bourassa, D V; Rigsby, L L

2011-07-01

101

Phylogenetic diversity and activity of aerobic heterotrophic bacteria from a hypersaline oil-polluted microbial mat.  

PubMed

The diversity and function of aerobic heterotrophic bacteria (AHB) in cyanobacterial mats have been largely overlooked. We used culture-dependent and molecular techniques to explore the species diversity, degradative capacities and functional guilds of AHB in the photic layer (2mm) of an oil-polluted microbial mat from Saudi Arabia. Enrichment isolation was carried out at different salinities (5% and 12%) and temperatures (28 and 45 degrees C) and on various substrates (acetate, glycolate, Spirulina extract and crude oils). Counts of most probable number showed a numerical abundance of AHB in the range of 1.15-8.13x10(6) cellsg(-1) and suggested the presence of halotolerant and thermotolerant populations. Most of the 16S rRNA sequences of the obtained clones and isolates were phylogenetically affiliated to the groups Gammaproteobacteria, Bacteriodetes and Alphaproteobacteria. Groups like Deltaproteobacteria, Verrucomicrobia, Planctomycetes, Spirochaetes, Acidobacteria and Deinococcus-Thermus were only detected by cloning. The strains isolated on acetate and glycolate belonged to the genera Marinobacter, Halomonas, Roseobacter and Rhodobacter whereas the strains enriched on crude oil belonged to Marinobacter and Alcanivorax. Members of the Bacteriodetes group were only enriched on Spirulina extract indicating their specialization in the degradation of cyanobacterial dead cells. The substrate spectra of representative strains showed the ability of all AHB to metabolize cyanobacterial photosynthetic and fermentation products. However, the unique in situ conditions of the mat apparently favored the enrichment of versatile strains that grew on both the cyanobacterial exudates and the hydrocarbons. We conclude that AHB in cyanobacterial mats represent a diverse community that plays an important role in carbon-cycling within microbial mats. PMID:17056222

Abed, Raeid M M; Zein, Burhanuddin; Al-Thukair, Assad; de Beer, Dirk

2006-10-23

102

Functional Relationship Between Phytoplankton and Aerobic Anoxygenic Photosynthetic Bacteria: Modes of Coexistence  

NASA Astrophysics Data System (ADS)

Aerobic Anoxygenic Photosynthetic Bacteria (AAPs) are ubiquitously distributed in the upper ocean. Although they contain bacteriochlorophyll a (BChla), the main absorption bands in the near UV (370 nm) and infrared (800-850 nm) make this pigment impractical in light harvesting below the first few meters of the water column. Instead, they utilize carotenoids as major light harvesting pigments. Since these carotenoids absorb in the 430-550 nm range, phytoplankton and AAPs utilize a similar portion of the available light spectrum. As AAPs cannot utilize water as the electron donor, they transfer electrons between a range of organic/inorganic electron donors and electron acceptors, thus significantly participating in the redox cycle in the upper ocean. We have measured the vertical distribution and photosynthetic properties of both phytoplankton and AAPs in a highly oligotrophic region 800 km SW of Monterey Bay (34N, 129W), and we have consistently observed the presence of a BChla maximum about 30 to 40 meters above the chlorophyll maximum, indicating that phytoplankton and AAPs occupy different ecological niches in the water column. However, the abundance of AAPs generally displayed a maximum at dawn and a minimum at the dusk, indicating a high level of mortality. This diel cycle was observed in 5 micron and 3 micron size fractions, indicating active grazing by small protists. Incubation experiments with natural, mixed population of AAPs and phytoplankton results in an unusually high accumulation of AAPs in DCMU-treated samples, indicating that pigmented protists do contribute significantly to AAP grazing in a tightly-controlled microbial loop. On the other hand, AAP incubations in pure cultures indicate that they biomineralize sulfur, thus affecting the sulfur cycle. All of these observations indicate that the role of AAPs in the upper ocean ecology is defined by their relationship with phototrophic and heterotrophic communities, rather than by their relative contribution to the carbon and energy cycles.

Kolber, Z. S.; Haffa, A.; Klimov, D.

2006-12-01

103

[Antimicrobial susceptibility of clinical isolates of aerobic gram-positive cocci and anaerobic bacteria in 2008].  

PubMed

The activity of antibacterial agents against aerobic Gram-positive cocci (25 genus or species, 1029 strains) and anaerobic bacteria (21 genus or species, 187 strains) isolated from clinical specimens in 2008 at 16 clinical facilities in Japan were studied using either broth microdilution or agar dilution method. The ratio of methicillin-resistant strains among Staphylococcus aureus and Staphylococcus epidermidis was 59.6% and 81.2%, suggesting that resistant strains were isolated at high frequency. Vancomycin (VCM), linezolid (LZD) and quinupristin/dalfopristin (QPR/DPR) had good antibacterial activity against methicillin-resistant S. aureus and methicillin-resistant S. epidermidis, with MIC90s of < or = 2 microg/mL. The ratio of penicillin (PC) intermediate and resistant strains classified by mutations of PC-binding proteins among Streptococcus pneumoniae was 92.0% that was highest among our previous reports. Cefpirome, carbapenems, VCM, teicoplanin (TEIC), LZD and QPR/DPR had MIC90s of < or = 1 microg/mL against PC-intermediate and resistant S. pneumoniae strains. Against all strains of Enterococcus faecalis and Enterococcus faecium, the MICs of VCM and TEIC were under 2 microg/mL, and no resistant strain was detected, suggesting that these agents had excellent activities against these species. 15.9% of E. faecalis strains and 1.2% of E. faecium strains showed intermediate to LZD. 17.1% of E. faecium strains showed intermediate or resistant to QPR/DPR. Against all strains of Clostridium difficile, the MIC of VCM was under 1 microg/mL, suggesting that VCM had excellent activity. Carbapenems showed good activity against Clostridiales, Bacteroides spp., and Prevotella spp., but one strain of Bacteroides fragilis showed resistant to carbapenems. And so, the susceptibility of this species should be well-focused in the future at detecting continuously. PMID:22808693

Yoshida, Isamu; Yamaguchi, Takahiro; Kudo, Reiko; Fuji, Rieko; Takahashi, Choichiro; Oota, Reiko; Kaku, Mitsuo; Kunishima, Hiroyuki; Okada, Masahiko; Horikawa, Yoshinori; Shiotani, Joji; Kino, Hiroyoshi; Ono, Yuka; Fujita, Shinichi; Matsuo, Shuji; Kono, Hisashi; Asari, Seishi; Toyokawa, Masahiro; Kusano, Nobuchika; Nose, Motoko; Horii, Toshinobu; Tanimoto, Ayako; Miyamoto, Hitoshi; Saikawa, Tetsunori; Hiramatsu, Kazufumi; Kohno, Shigeru; Yanagihara, Katsunori; Yamane, Nobuhisa; Nakasone, Isamu; Maki, Hideki; Yamano, Yoshinori

2012-02-01

104

[Antimicrobial susceptibility of clinical isolates of aerobic Gram-positive cocci and anaerobic bacteria in 2006].  

PubMed

The activity of antibacterial agents against aerobic Gram-positive cocci (26 species, 1022 strains) and anaerobic bacteria (23 species, 184 strains) isolated from clinical specimens in 2006 at 16 clinical facilities in Japan were studied using either broth microdilution or agar dilution method. The ratio of methicillin-resistant strains among Staphylococcus aureus and Staphylococcus epidermidis was 53.0% and 65.8%, suggesting that resistant strains were isolated at high frequency. Vancomycin (VCM) and quinupristin/dalfopristin (QPR/DPR) had good antibacterial activity against methicillin-resistant S. aureus and methicillin-resistant S. epidermidis, with MIC90s of < or = 2 micrcog/mL. The ratio of penicillin (PC) intermediate and resistant strains classified by mutations of PC-binding proteins among Streptococcus pneumoniae was 87.6%. Ceftriaxone, cefpirome, cefepime, carbapenem antibiotics, VCM, teicoplanin, linezolid(LZD) and QPR/DPR had MIC90s of < or = 1 microg/mL against PC-intermediate and resistant S. pneumoniae strains. Against all strains of Enterococcus faecalis and Enterococcus faecium, the MICs of VCM and TEIC were under 2 microg/mL, and no resistant strain was detected, suggesting that these agents had excellent activities against these species. 10.9% of E. faecalis strains or 3.5% of E. faecium strains showed intermediate or resistant to LZD. 24.4% of E. faecium strains showed intermediate or resistant to QPR/DPR. Against all strains of Clostridium difficile, the MIC of VCM were under 1 microg/mL, suggesting that VCM had excellent activity against C. difficile. Carbapenems showed good activity against Peptococcaceae, Bacteroides spp., and Prevotella spp. However since several strains of Bacteroides fragilis showed resistant to carbapenems and the susceptibility of this species should be well-focused in the future. PMID:21425596

Yamaguchi, Takahiro; Yoshida, Isamu; Itoh, Yoshihisa; Tachibana, Mineji; Takahashi, Choichiro; Kaku, Mitsuo; Kanemitsu, Keiji; Okada, Masahiko; Horikawa, Yoshinori; Shiotani, Joji; Kino, Hiroyoshi; Ono, Yuka; Baba, Hisashi; Matsuo, Shuji; Asari, Seishi; Toyokawa, Masahiro; Matsuoka, Kimiko; Kusano, Nobuchika; Nose, Motoko; Murase, Mitsuharu; Miyamoto, Hitoshi; Saikawa, Tetsunori; Hiramatsu, Kazufumi; Kohno, Shigeru; Yanagihara, Katsunori; Yamane, Nobuhisa; Nakasone, Isamu; Maki, Hideki; Yamano, Yoshinori

2010-12-01

105

Prevalence of Anaerobic and Aerobic Bacteria in Early Onset Neonatal Sepsis  

Microsoft Academic Search

Background: To determine prospectively the prevalence of anaerobic and aerobic infection in early onset (during 72 hours of age) neonatal sepsis, in Tehran Vali-e-Asr Hospital. Methods: Among all the live birth, neonates suspecting of having septicemia were investigated for isolation of micro- organisms. Culture bottle containing enriched tryptic soy broth was used for standard blood culture system to detect aerobes

F Nili; E Amini; F Nayeri; M Aligholi; M Emaneini

106

Polyphosphate-accumulating and denitrifying bacteria isolated from anaerobic-anoxic and anaerobic-aerobic sequencing batch reactors  

PubMed

In this study, phosphate-accumulating bacteria achieved complete phosphate removal in two different systems: an anaerobic-anoxic sequencing batch reactor and an anaerobic-aerobic sequencing batch reactor. This result shows that phosphate-accumulating bacteria in the A2 SBR can use nitrate as terminal electron acceptor instead of oxygen. Phosphate-accumulating bacteria accumulated phosphate with a rates between 30 and 70 mg P/L/h in the A/O SBR and between 15 and 32 mg P/L/h in the A2 SBR. Twenty denitrifying isolates were screened from A2 SBR and nine from A/O SBR. Identification of these isolates by the Biolog system and the API 20 NE identification kit revealed that the most active denitrifiers in both SBRs reactors were species of Ochrobactrum, Pseudomonas, Corynebacterium, Agrobacterium, Aquaspirillum, Haemophilus, Xanthomonas, Aeromonas, and Shewanella. The most active phosphate accumulating and denitrifying bacteria were identified as Agrobacterium tumefaciens B, Aquaspirillum dispar, and Agrobacterium radiobacter. This study showed that the active phosphate accumulating-bacteria were also the most efficient denitrifying bacteria in both reactors. PMID:9841775

Merzouki; Delgenes; Bernet; Moletta; Benlemlih

1999-01-01

107

Characteristics of aerobic and anaerobic ammonium-oxidizing bacteria in the hyporheic zone of a contaminated river.  

PubMed

Both ?-proteobacterial aerobic ammonium-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing (ANAMMOX) bacteria were investigated in the hyporheic zone of a contaminated river in China containing high ammonium levels and low chemical oxygen demand. Fluorescence in-situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE) and cloning-sequencing were employed in this study. FISH analysis illustrated that AOB (average population of 3.5 %) coexisted with ANAMMOX bacteria (0.7 %). The DGGE profile revealed a high abundance and diversity of bacteria at the water-air-soil interface rather than at the water-soil interface. The redundancy analysis correlated analysis showed that the diversity of ANAMMOX bacteria was positively related to the redox potential. The newly detected sequences of ANAMMOX organisms principally belonged to the genus Candidatus "Brocadia", while most ammonia monooxygenase subunit-A gene amoA sequences were affiliated with Nitrosospira and Nitrosomonas. These results suggest that the water-air-soil interface performs an important function in the nitrogen removal process and that the bioresources of AOB and ANAMMOX bacteria can potentially be utilized for the eutrophication of rivers. PMID:22806720

Wang, Ziyuan; Qi, Yun; Wang, Jun; Pei, Yuansheng

2012-06-07

108

Aerobic organic carbon mineralization by sulfate-reducing bacteria in the oxygen-saturated photic zone of a hypersaline microbial mat.  

PubMed

The sulfate-reducing bacterium strain SRB D2 isolated from the photic zone of a hypersaline microbial mat, from Lake Chiprana, NE Spain, respired pyruvate, alanine, and alpha-ketoglutarate but not formate, lactate, malate, succinate, and serine at significant rates under fully oxic conditions. Dehydrogenase enzymes of only the former substrates are likely oxygen-tolerant as all substrates supported anaerobic sulfate reduction. No indications were found, however, that aerobic respiration supported growth. Although strain SRB D2 appeared phylogenetically closely related to the oxygen-tolerant sulfate-reducing bacterium Desulfovibrio oxyclinae, substrate spectra were markedly different. Most-probable-number (MPN) estimates of sulfate-reducing bacteria and aerobic heterotrophic bacteria indicated that the latter were numerically dominant in both the photic and aphotic zones of the mat. Moreover, substrate spectra of representative isolates showed that the aerobic heterotrophic bacteria are metabolically more diverse. These findings indicate that sulfate-reducing bacteria in the fully oxic photic zone of mats have to compete with aerobic heterotrophic bacteria for organic substrates. Porewater analysis revealed that total carbohydrates and low-molecular-weight carbon compounds (LMWC) made up substantial fractions of the total dissolved organic carbon (DOC) pool and that nighttime degradation of the former was concomitant with increased concentration of the latter. Our findings indicate that aerobic respiration by sulfate-reducing bacteria contributes to organic carbon mineralization in the oxic zone of microbial mats as daytime porewater LMWC concentrations are above typical half-saturation constants. PMID:15965719

Jonkers, H M; Koh, I-O; Behrend, P; Muyzer, G; de Beer, D

2005-06-17

109

Comparative antimicrobial susceptibility of aerobic and facultative bacteria from community-acquired bacteremia to ertapenem in Taiwan  

PubMed Central

Background Ertapenem is a once-a-day carbapenem and has excellent activity against many gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria. The susceptibility of isolates of community-acquired bacteremia to ertapenem has not been reported yet. The present study assesses the in vitro activity of ertapenem against aerobic and facultative bacterial pathogens isolated from patients with community-acquired bacteremia by determining and comparing the MICs of cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin. The prevalence of extended broad spectrum ?-lactamases (ESBL) producing strains of community-acquired bacteremia and their susceptibility to these antibiotics are investigated. Methods Aerobic and facultative bacteria isolated from blood obtained from hospitalized patients with community-acquired bacteremia within 48 hours of admission between August 1, 2004 and September 30, 2004 in Chang Gung Memorial Hospital at Keelung, Taiwan, were identified using standard procedures. Antimicrobial susceptibility was evaluated by Etest according to the standard guidelines provided by the manufacturer and document M100-S16 Performance Standards of the Clinical Laboratory of Standard Institute. Antimicrobial agents including cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin were used against the bacterial isolates to test their MICs as determined by Etest. For Staphylococcus aureus isolates, MICs of oxacillin were also tested by Etest to differentiate oxacillin-sensitive and oxacillin-resistant S. aureus. Results Ertapenem was highly active in vitro against many aerobic and facultative bacterial pathogens commonly recovered from patients with community-acquired bacteremia (128/159, 80.5 %). Ertapenem had more potent activity than ceftriaxone, piperacillin-tazobactam, or ciprofloxacin against oxacillin-susceptible S. aureus (17/17, 100%)and was more active than any of these agents against enterobacteriaceae (82/82, 100%). Conclusion Based on the microbiology pattern of community-acquired bacteremia, initial empiric treatment that requires coverage of a broad spectrum of both gram-negative and gram-positive aerobic bacteria, such as ertapenem, may be justified in moderately severe cases of community-acquired bacteremia in non-immunocompromised hosts.

Lee, Sai-Cheong; Huang, Shie-Shian; Lee, Chao-Wei; Fung, Chang-Phone; Lee, Ning; Shieh, Wen-Bin; Siu, LK

2007-01-01

110

Aerobic bacterial flora of oral and nasal fluids of canines with reference to bacteria associated with bites.  

PubMed Central

Oral and nasal fluids of 50 dogs were examined to determine the prevalence of aerobic bacteria frequently associated with animal bite wounds. The most frequently isolated microorganisms included: IIj, EF-4, Pasteurella multocida, Staphylococcus aureus, Staphylococcus epidermidis, group D streptococci, Corynebacterium sp., Enterobacteria, Neisseria sp., Moraxella sp., and Bacillus sp. Other species and genera were infrequently recovered and may represent transient flora. The high incidence of IIj, EF-4, P. multocida, and S. aureus, all known human pathogens, suggests that they should be considered as probably contaminants in bite wounds. Images

Bailie, W E; Stowe, E C; Schmitt, A M

1978-01-01

111

Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea  

NASA Astrophysics Data System (ADS)

Aerobic anoxygenic phototrophic (AAP) bacteria play significant roles in the bacterioplankton productivity and biogeochemical cycles of the surface ocean. In this study, we applied both cultivation and mRNA-based molecular methods to explore the diversity of AAP bacteria along an oligotrophic gradient in the Mediterranean Sea in early summer 2008. Colony-forming units obtained on three different agar media were screened for the production of bacteriochlorophyll-a (BChl-a), the light-harvesting pigment of AAP bacteria. BChl-a-containing colonies represented a low part of the cultivable fraction. In total, 54 AAP strains were isolated and the phylogenetic analyses based on their 16S rRNA and pufM genes showed that they were all affiliated to the Alphaproteobacteria. The most frequently isolated strains belonged to Citromicrobium bathyomarinum, and Erythrobacter and Roseovarius species. Most other isolates were related to species not reported to produce BChl-a and/or may represent novel taxa. Direct extraction of RNA from seawater samples enabled the analysis of the expression of pufM, the gene coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis. Clone libraries of pufM gene transcripts revealed that most phylotypes were highly similar to sequences previously recovered from the Mediterranean Sea and a large majority (~94 %) was affiliated to the Gammaproteobacteria. The most abundantly detected phylotypes occurred in the western and eastern Mediterranean basins. However, some were exclusively detected in the eastern basin, reflecting the highest diversity of pufM transcripts observed in this ultra-oligotrophic region. To our knowledge, this is the first study to document extensively the diversity of AAP isolates and to unveil the active AAP community in an oligotrophic marine environment. By pointing out the discrepancies between culture-based and molecular methods, this study highlights the existing gaps in the understanding of the AAP bacteria ecology, especially in the Mediterranean Sea and likely globally.

Jeanthon, C.; Boeuf, D.; Dahan, O.; Le Gall, F.; Garczarek, L.; Bendif, E. M.; Lehours, A.-C.

2011-07-01

112

Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea  

NASA Astrophysics Data System (ADS)

Aerobic anoxygenic phototrophic (AAP) bacteria play significant roles in the bacterioplankton productivity and biogeochemical cycles of the surface ocean. In this study, we applied both cultivation and mRNA-based molecular methods to explore the diversity of AAP bacteria along an oligotrophic gradient in the Mediterranean Sea in early summer 2008. Colony-forming units obtained on three different agar media were screened for the production of bacteriochlorophyll-a (BChl-a), the light-harvesting pigment of AAP bacteria. BChl-a-containing colonies represented a low part of the cultivable fraction. In total, 52 AAP strains were isolated and the phylogenetic analyses based on their 16S rRNA and pufM genes showed that they were all affiliated to the Alphaproteobacteria. The most frequently isolated strains belonged to Citromicrobium bathyomarinum, and Erythrobacter and Roseovarius species. Most other isolates were related to species not reported to produce BChl-a and/or may represent novel taxa. Direct extraction of RNA from seawater samples enabled the analysis of the expression of pufM, the gene coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis. Clone libraries of pufM gene transcripts revealed that most phylotypes were highly similar to sequences previously recovered from the Mediterranean Sea and a large majority (~94%) was affiliated with the Gammaproteobacteria. The most abundantly detected phylotypes occurred in the western and eastern Mediterranean basins. However, some were exclusively detected in the eastern basin, reflecting the highest diversity of pufM transcripts observed in this ultra-oligotrophic region. To our knowledge, this is the first study to document extensively the diversity of AAP isolates and to unveil the active AAP community in an oligotrophic marine environment. By pointing out the discrepancies between culture-based and molecular methods, this study highlights the existing gaps in the understanding of the AAP bacteria ecology, especially in the Mediterranean Sea and likely globally.

Jeanthon, C.; Boeuf, D.; Dahan, O.; Le Gall, F.; Garczarek, L.; Bendif, E. M.; Lehours, A.-C.

2011-05-01

113

Aerobic endospore-forming bacteria from geothermal environments in northern Victoria Land, Antarctica, and Candlemas Island, South Sandwich archipelago, with the proposal of Bacillus fumarioli sp. nov  

Microsoft Academic Search

Aerobic endospore-forming bacteria were isolated from soils taken from active fumaroles on Mount Rittmann and Mount Melbourne in northern Victoria Land, Antarctica, and from active and inactive fumaroles on Candlemas Island, South Sandwich archipelago. The Mt Rittmann and Mt Melbourne soils yielded a dominant, moderately thermophilic and acidophilic, aerobic endospore- former growing at pH 5<5 and 50SC, and further strains

N. A. Logan; L. Lebbe; B. Hoste; J. Goris; G. Forsyth; M. Heyndrickx; B. L. Murray; N. Syme; D. D. Wynn-Williams; P. De Vos

114

Dynamic and distribution of ammonia-oxidizing bacteria communities during sludge granulation in an anaerobic-aerobic sequencing batch reactor.  

PubMed

The structure dynamic of ammonia-oxidizing bacteria (AOB) community and the distribution of AOB and nitrite-oxidizing bacteria (NOB) in granular sludge from an anaerobic-aerobic sequencing batch reactor (SBR) were investigated. A combination of process studies, molecular biotechniques and microscale techniques were employed to identify and characterize these organisms. The AOB community structure in granules was substantially different from that of the initial pattern of the inoculants sludge. Along with granules formation, the AOB diversity declined due to the selection pressure imposed by process conditions. Denaturing gradient gel electrophoresis (DGGE) and sequencing results demonstrated that most of Nitrosomonas in the inoculating sludge were remained because of their ability to rapidly adapt to the settling-washing out action. Furthermore, DGGE analysis revealed that larger granules benefit more AOB species surviving in the reactor. In the SBR were various size granules coexisted, granule diameter affected the distribution range of AOB and NOB. Small and medium granules (d<0.6 mm) cannot restrict oxygen mass transfer in all spaces of the sludge. Larger granules (d>0.9 mm) can result in smaller aerobic volume fraction and inhibition of NOB growth. All these observations provide support to future studies on the mechanisms responsible for the AOB in granules systems. PMID:21955984

Bin, Zhang; Zhe, Chen; Zhigang, Qiu; Min, Jin; Zhiqiang, Chen; Zhaoli, Chen; Junwen, Li; Xuan, Wang; Jingfeng, Wang

2011-09-17

115

Space agriculture for habitation on Mars with hyper-thermophilic aerobic composting bacteria  

Microsoft Academic Search

Manned Mars exploration requires recycle of materials to support human life A conceptual design is developed for space agriculture which is driven by the biologically regenerative function Hyper-thermophilic aerobic composting bacterial ecology is the core of materials recycling system to process human metabolic waste and inedible biomass and convert them to fertilizer for plants cultivation A photosynthetic reaction of plants

S. Kanazawa; Y. Ishikawa; K. Tomita-Yokotani; H. Hashimoto; Y. Kitaya; M. Yamashita; M. Nagatomo; T. Oshima; H. Wada

2006-01-01

116

Multilocus enzyme analysis in aerobic and anaerobic bacteria using gel electrophoresis–nitrocellulose blotting  

Microsoft Academic Search

An optimized multilocus enzyme electrophoresis method, which involves polyacrylamide–agarose gel electrophoresis followed by electrophoretic transfers on nitrocellulose sheets, was developed for the analysis of enzyme polymorphism in several aerobic and anaerobic bacterial species including Staphylococcus aureus, Streptococcus pneumoniae, S. agalactiae, Klebsiella pneumoniae and K. oxytoca, Clostridium bifermentans and C. sordellii, and Prevotella bivia. Serial electrophoretic transfers (during 5–15 min each)

Marie-Laure Combe; Jean-François Lemeland; Martine Pestel-Caron; Jean-Louis Pons

2000-01-01

117

Characteristics of the bacteriocin produced by Lactococcus lactis subsp. cremoris CTC 204 and the effect of this compound on the mesophilic bacteria associated with raw beef  

Microsoft Academic Search

Summary >Screening for the bacteriocin production of strains of lactic acid bacteria from various meat and meat products resulted in the detection of a bacteriocin-producing Lactococcus lactis subsp. cremoris CTC 204, isolated from chicken. The bacteriocin inhibited not only closely related lactic acid bacteria (Lactobacillus helveticus), but also pathogenic microorganisms (Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, and Clostridium perfringens). It

R. Bromberg; I. Moreno; R. R. Delboni; H. C. Cintra; P. T. V Oliveira

2005-01-01

118

Biotransformation Patterns of 2,4,6Trinitrotoluene by Aerobic Bacteria  

Microsoft Academic Search

.   2,4,6-Trinitrotoluene (TNT), a toxic nitroaromatic explosive, accumulates in the environment, making necessary the remediation\\u000a of contaminated areas and unused materials. Although bioremediation has been utilized to detoxify TNT, the metabolic processes\\u000a involved in the metabolism of TNT have proven to be complex. The three aerobic bacterial strains reported here (Pseudomonas aeruginosa, Bacillus sp., and Staphylococcus sp.) differ in their

Tim Kalafut; Melinda E. Wales; Vipin K. Rastogi; Rimma P. Naumova; Soniya K. Zaripova; James R. Wild

1998-01-01

119

Dispersal of Aerobic Endospore-forming Bacteria from Soil and Agricultural Activities to Food and Feed  

Microsoft Academic Search

\\u000a For specific aerobic endospore-formers, the soil route of contamination or dispersal is the start of what is sometimes a long\\u000a series of events or processes in the agro-food chain that eventually leads to important problems or concerns for food safety\\u000a and\\/or quality. In the dairy sector, Bacillus cereus is the most important pathogen or spoilage organism that, through the faecal

Marc Heyndrickx

120

Aerobic metabolism of vitamin E by marine bacteria: Interaction with free radical oxidation (autoxidation) processes  

Microsoft Academic Search

The degradation of vitamin E by aerobic bacterial communities, isolated from marine sediment and microbial mat samples, was investigated. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles and cloning\\/sequencing experiments revealed that biodegradation of vitamin E in sediments is mainly carried out by strains belonging to the genera Idiomarina and Bacillus, for which the DGGE pattern matched the pattern obtained

Jean-François Rontani; Mina Nassiry; Sophie Guasco; Abdelkrim Mouzdahir; Patricia Bonin

2008-01-01

121

Roseobacter-Like Bacteria in Red and Mediterranean Sea Aerobic Anoxygenic Photosynthetic Populations  

Microsoft Academic Search

Bacteriochlorophyll a-containing aerobic anoxygenic phototrophs (AAnP) have been proposed to account for up to 11% of the total surface water microbial community and to potentially have great ecological importance in the world's oceans. Recently, environmental and genomic data based on analysis of the pufM gene identified the existence of -proteobacteria as well as possible -like proteobacteria among AAnP in the

Aia Oz; Gazalah Sabehi; M. Koblizek; Ramon Massana

2005-01-01

122

Radioassay for Hydrogenase Activity in Viable Cells and Documentation of Aerobic Hydrogen-Consuming Bacteria Living in Extreme Environments  

PubMed Central

An isotopic tracer assay based on the hydrogenase-dependent formation of tritiated water from tritium gas was developed for in life analysis of microbial hydrogen transformation. This method allowed detection of bacterial hydrogen metabolism in pure cultures or in natural samples obtained from aquatic ecosystems. A differentiation between chemical-biological and aerobic-anaerobic hydrogen metabolism was established by variation of the experimental incubation temperature or by addition of selective inhibitors. Hydrogenase activity was shown to be proportional to the consumption or production of hydrogen by cultures of Desulfovibrio vulgaris, Clostridium pasteurianum, and Methanosarcina barkeri. This method was applied, in connection with measurements of free hydrogen and most-probable-number enumerations, in aerobic natural source waters to establish the activity and document the ecology of hydrogen-consuming bacteria in extreme acid, thermal, or saline environments. The utility of the assay is based in part on the ability to quantify bacterial hydrogen transformation at natural hydrogen partial pressures, without the use of artificial electron acceptors.

Schink, Bernhard; Lupton, F. S.; Zeikus, J. G.

1983-01-01

123

Radioassay for hydrogenase activity in viable cells and documentation of aerobic hydrogen-consuming bacteria living in extreme environments  

SciTech Connect

An isotopic tracer assay based on the hydrogenase-dependent formation of tritiated water from tritium gas was developed for in life analysis of microbial hydrogen transformation. This method allowed detection of bacterial hydrogen metabolism in pure cultures or in natural samples obtained from aquatic ecosystems. A differentiation between chemical-biological and aerobic-anaerobic hydrogen metabolism was established by variation of the experimental incubation temperature or by addition of selective inhibitors. Hydrogenase activity was shown to be proportional to the consumption or production of hydrogen by cultures of Desulfovibrio vulgaris, Clostridium pasteurianum, and Methanosarcina barkeri. This method was applied, in connection with measurements of free hydrogen and most-probable-number enumerations, in aerobic natural source waters to establish the activity and document the ecology of hydrogen-consuming bacteria in extreme acid, thermal, or saline environments. The utility of the assay is based in part on the ability to quantify bacterial hydrogen transformation at natural hydrogen partial pressures, without the use of artificial electron acceptors.

Schink, B.; Lupton, F.S.; Zeikus, J.G.

1983-05-01

124

Abundance, depth distribution, and composition of aerobic bacteriochlorophyll a-producing bacteria in four basins of the central Baltic Sea.  

PubMed

The abundance, vertical distribution, and diversity of aerobic anoxygenic phototrophic bacteria (AAP) were studied at four basins of the Baltic Sea. AAP were enumerated by infrared epifluorescence microscopy, and their diversity was analyzed by using pufM gene clone libraries. In addition, numbers of CFU containing the pufM gene were determined, and representative strains were isolated. Both approaches indicated that AAP reached maximal abundance in the euphotic zone. Maximal AAP abundance was 2.5 x 10(5) cells ml(-1) (11% of total prokaryotes) or 1.0 x 10(3) CFU ml(-1) (9 to 10% of total CFU). Environmental pufM clone sequences were grouped into 11 operational taxonomic units phylogenetically related to cultivated members of the Alpha-, Beta-, and Gammaproteobacteria. In spite of varying pufM compositions, five clones were present in all libraries. Of these, Jannaschia-related clones were always found in relative abundances representing 25 to 30% of the total AAP clones. The abundances of the other clones varied. Clones potentially affiliated with typical freshwater Betaproteobacteria sequences were present at three Baltic Sea stations, whereas clones grouping with Loktanella represented 40% of the total cell numbers in the Gotland Basin. For three alphaproteobacterial clones, probable pufM phylogenetic relationships were supported by 16S rRNA gene analyses of Baltic AAP isolates, which showed nearly identical pufM sequences. Our data indicate that the studied AAP assemblages represented a mixture of marine and freshwater taxa, thus characterizing the Baltic Sea as a "melting pot" of abundant, polyphyletic aerobic photoheterotrophic bacteria. PMID:18502937

Salka, Ivette; Moulisová, Vladimíra; Koblízek, Michal; Jost, Günter; Jürgens, Klaus; Labrenz, Matthias

2008-05-23

125

Survival of Aerobic and Anaerobic Bacteria in Purulent Clinical Specimens Maintained in the Copan Venturi Transystem and Becton Dickinson Port-a-Cul Transport Systems  

PubMed Central

Recovery of aerobic and anaerobic bacteria from clinical specimens maintained in the Copan Venturi Transystem and the Becton Dickinson Port-a-Cul transport was assessed. Of 54 anaerobes, 53 were recovered after 4 h, and 52 were recovered after 24 h, from both systems. After 48 h, 45 and 50 were recovered from the two systems, respectively.

Citron, Diane M.; Warren, Yumi A.; Hudspeth, Marie K.; Goldstein, Ellie J. C.

2000-01-01

126

Comparison of media and diluents for enumeration of aerobic bacteria from Bermuda grass golf course putting greens 1 Florida Agricultural Experiment Station Journal Series no. R-06427. 1  

Microsoft Academic Search

To increase our knowledge of soil and rhizosphere bacteria associated with bermuda grass grown on golf courses, a standardized procedure has been developed. Seven aerobic bacterial groups were selected for enumeration. For each group selected, appropriate media were compared to determine which one was best for enumeration of that group. Six diluents were evaluated across all media for the seven

M. L Elliott; E. A Des Jardin

1999-01-01

127

The Effect of Bacteria+Enzyme Mixture Silage Inoculant on the Fermentation Characteristic, Cell Wall Contents and Aerobic Stabilities of Maize Silage  

Microsoft Academic Search

This research was carried out to determine the effects of Bacteria+Enzyme mixture inoculant using as silage additives on the fermentation characteristics, cell wall contents and aerobic stabilities of maiz e silages. Maize silage was harvested at milk blood stage. Maize-All (Alltech, UK) was used as additive which contains Lactobacillus plantarum, Pediococcus acidilactici and amylase in its biological composition. Maize was

Fisun Koc; Levent Coskuntuna; M. Levent Ozduven

2008-01-01

128

Comparative analysis of the diversity of aerobic spore-forming bacteria in raw milk from organic and conventional dairy farms.  

PubMed

Bacterial contamination of raw milk can originate from different sources: air, milking equipment, feed, soil, faeces and grass. It is hypothesized that differences in feeding and housing strategies of cows may influence the microbial quality of milk. This assumption was investigated through comparison of the aerobic spore-forming flora in milk from organic and conventional dairy farms. Laboratory pasteurized milk samples from five conventional and five organic dairy farms, sampled in late summer/autumn and in winter, were plated on a standard medium and two differential media, one screening for phospholipolytic and the other for proteolytic activity of bacteria. Almost 930 isolates were obtained of which 898 could be screened via fatty acid methyl ester analysis. Representative isolates were further analysed using 16S rRNA gene sequencing and (GTG)(5)-PCR. The majority of aerobic spore-formers in milk belonged to the genus Bacillus and showed at least 97% 16S rRNA gene sequence similarity with type strains of Bacillus licheniformis, Bacillus pumilus, Bacillus circulans, Bacillus subtilis and with type strains of species belonging to the Bacillus cereus group. About 7% of all isolates may belong to possibly new spore-forming taxa. Although the overall diversity of aerobic spore-forming bacteria in milk from organic vs. conventional dairy farms was highly similar, some differences between both were observed: (i) a relatively higher number of thermotolerant organisms in milk from conventional dairy farms compared to organic farms (41.2% vs. 25.9%), and (ii) a relatively higher number of B. cereus group organisms in milk from organic (81.3%) and Ureibacillus thermosphaericus in milk from conventional (85.7%) dairy farms. One of these differences, the higher occurrence of B. cereus group organisms in milk from organic dairy farms, may be linked to differences in housing strategy between the two types of dairy farming. However, no plausible clarification was found for the relatively higher number of thermotolerant organisms and the higher occurrence of U. thermosphaericus in milk from conventional dairy farms. Possibly this is due to differences in feeding strategy but no decisive indications were found to support this assumption. PMID:18406093

Coorevits, An; De Jonghe, Valerie; Vandroemme, Joachim; Reekmans, Rieka; Heyrman, Jeroen; Messens, Winy; De Vos, Paul; Heyndrickx, Marc

2008-04-10

129

Diversity and activity of cultivable aerobic planktonic bacteria of a saline Lake located in Sovata, Romania.  

PubMed

Aerobic bacterial strains from the salt water of Lake Red (Sovata, Romania) were cultivated. More than half of the 80 strains were G(-) and formed motile straight rods. Only a few strains produced acid from D-glucose and reduced nitrate to nitrite. Optimum NaCl concentration for growth varied between 5 and 15 % in the majority of the strains, so the isolates were regarded moderately halophilic. On the basis of the 16S rRNA gene sequence similarity almost half of the strains were identified as members of genus Halomonas. Other strains belonged to genera Marinobacter, Psychrobacter, Serratia, Morganella (?-Proteobacteria), Bacillus, Exiguobacterium, Planococcus (Firmicutes), and Arthrobacter, Micrococcus, Microbacterium, and Nesterenkonia (Actinobacteria). PMID:20941581

Borsodi, A K; Kiss, R I; Cech, G; Vajna, B; Tóth, E M; Márialigeti, K

2010-10-13

130

Biotransformation patterns of 2,4,6-trinitrotoluene by aerobic bacteria.  

PubMed

2,4,6-Trinitrotoluene (TNT), a toxic nitroaromatic explosive, accumulates in the environment, making necessary the remediation of contaminated areas and unused materials. Although bioremediation has been utilized to detoxify TNT, the metabolic processes involved in the metabolism of TNT have proven to be complex. The three aerobic bacterial strains reported here (Pseudomonas aeruginosa, Bacillus sp. , and Staphylococcus sp.) differ in their ability to biotransform TNT and in their growth characteristics in the presence of TNT. In addition, enzymatic activities have been identified that differ in the reduction of nitro groups, cofactor preferences, and the ability to eliminate-NO2 from the ring. The Bacillus sp. has the most diverse bioremediation potential owing to its growth in the presence of TNT, high level of reductive ability, and capability of removing-NO2 from the nitroaromatic ring. PMID:9405746

Kalafut, T; Wales, M E; Rastogi, V K; Naumova, R P; Zaripova, S K; Wild, J R

1998-01-01

131

A survey of the aerobic bacteria in the feces of captive raptors.  

PubMed

Feces of 47 captive raptors belonging to the order Falconiformes or Strigiformes were cultured for bacteria. Gram-negative bacteria, which were cultured from the feces of 45 of the 47 raptors, were the most common isolates. A wide variety of species were identified, including a newly described genus (Moellerella wisconsensis), two newly described species (Escherichia fergusonii and Proteus penneri), and a member of a newly described enteric group (CDC Enteric group 41). Additional organisms identified that have not been reported in previous bacteriological surveys of raptors were Salmonella heidelberg, Salmonella braenderup, Morganella morganii, Yersinia ruckeri, Serratia spp., and Kluyvera sp. Escherichia coli, isolated from the feces of 42 of the 47 raptors, was the most frequently recovered. Streptococcus faecalis, the second most common isolate, was cultured from 30 birds. Several differences were observed between fecal bacteria isolated from raptors fed commercially prepared chicken and those isolated from raptors not fed chicken. The most obvious difference was that birds fed chicken had more varied gram-negative bacterial species and in greater numbers per fecal sample. The potential for the isolated bacteria from raptors as pathogens in humans and avian species is discussed. PMID:3382380

Bangert, R L; Ward, A C; Stauber, E H; Cho, B R; Widders, P R

132

Contribution of Aerobic Photoheterotrophic Bacteria to the Carbon Cycle in the Ocean  

Microsoft Academic Search

The vertical distribution of bacteriochlorophyll a, the numbers of infrared fluorescent cells, and the variable fluorescence signal at 880 nanometers wave- length, all indicate that photosynthetically competent anoxygenic phototrophic bacteria are abundant in the upper open ocean and comprise at least 11% of the total microbial community. These organisms are facultative photohetero- trophs, metabolizing organic carbon when available, but are

Zbigniew S. Kolber; F. Gerald Plumley; Andrew S. Lang; J. Thomas Beatty; Robert E. Blankenship; Cindy L. VanDover; Costantino Vetriani; Michal Koblizek; Christopher Rathgeber; Paul G. Falkowski

2001-01-01

133

Denaturing gradient gel electrophoresis used to monitor the enrichment culture of aerobic chemoorganotrophic bacteria from a hot spring cyanobacterial mat.  

PubMed Central

Previous studies investigating microbial diversity in the Octopus Spring cyanobacterial mat community (Yellowstone National Park) have shown a discrepancy between bacterial populations observed by molecular retrieval and cultivation techniques. To investigate how selective enrichment culture techniques affect species composition, we used denaturing gradient gel electrophoresis (DGGE) separation of PCR-amplified 16S rRNA gene fragments to monitor the populations contained within enrichment cultures of aerobic chemoorganotrophic bacteria from the ca. 50 degrees C region of the mat community. By varying the degree of dilution of the inoculum, medium composition, and enrichment conditions and duration and by analyzing the cultures by DGGE, we detected 14 unique 16S rRNA sequence types. These corresponded to alpha-, beta-, gamma-, and delta-proteobacteria, Thermus relatives, and gram-positive bacteria with high G + C ratio and, at the highest inoculum dilutions, Chloroflexus aurantiacus relatives, which were estimated to still be approximately 300 times less abundant than cells of the mat primary producer, Synechococcus spp. Only three of these populations were previously cultivated on solidified medium after similar enrichment. Only two of these population have 16S rRNA sequences which were previously cloned directly from the mat. These results reveal a diversity of bacterial populations in enrichment culture which were not detected by either molecular retrieval or strain purification techniques.

Santegoeds, C M; Nold, S C; Ward, D M

1996-01-01

134

Cook\\/chill foodservice system with a microwave oven: Injured aerobic bacteria during food product flow  

Microsoft Academic Search

Summary  This study determined how processing in cook\\/chill foodservice systems affected the quantity of sublethally injured bacteria\\u000a in food. Beef loaf and frozen green beans were each prepared three times in a laboratory simulation following time-temperature\\u000a recommendations of the Hazard Analysis Critical Control Point model. Beef loaf (15 kg) was initially cooked (1 kg\\/loaf) to\\u000a a mean and temperature of 66C;

C. A. Dahl; M. E. Matthews; E. H. Marth

1981-01-01

135

Aerobic degradation of di- and trichlorobenzenes by two bacteria isolated from polluted tropical soils  

Microsoft Academic Search

Two polychlorinated biphenyl (PCBs)-degrading bacteria were isolated by traditional enrichment technique from electrical transformer fluid (Askarel)-contaminated soils in Lagos, Nigeria. They were classified and identified as Enterobacter sp. SA-2 and Pseudomonas sp. SA-6 on the basis of 16S rRNA gene analysis, in addition to standard cultural and biochemical techniques. The strains were able to grow extensively on dichloro- and trichlorobenzenes.

Sunday A. Adebusoye; Flynn W. Picardal; Matthew O. Ilori; Olukayode O. Amund; Clay Fuqua; Nathan Grindle

2007-01-01

136

Distribution and persistence of Staphylococcus and Micrococcus species and other aerobic bacteria on human skin.  

PubMed

The districution of Staphylococcus and Micrococcus species and associated coryneform bacteria, Acinetobacter, Klebsiella, Enterobacter, Bacillus, and Streptomyces on skin was determined during October 1971 from samples collected on persons living in North Carolina and New Jersey. Persistence of these organisms on skin was estimated in temporal studies conducted during the period from June 1971 to June 1972 on persons living in North Carolina. Staphylococci and coryneforms were the most predominant and persistent bacteria isolated from the nares and axillae. Staphylococci, coryneforms, micrococci, and Bacillus were the most predominant and persistent bacteria isolated from the head, legs, and arms. Acinetobacters were most frequently isolated during the warmer months of the years. Staphylococcus aureus and S. epidermidis were the most predominant and persistent staphylococci isolated from the nares, whereas S. epidermidis and S. hominis were the most predominant and persistent staphylocicci isolated from the axillae, head, legs, and arms. S. capitis was often isolated from the head and arms and S. haemolyticus was often isolated from the head, legs, and arms. S. simulans, S. xylosus, S. cohnii, S. saprophyticus, S. warneri, and an unclassified coagulase-positive species were only occasionally isolated from skin. Micrococcus luteus was the most predominant and persistent Micrococcus isolated from skin and preferred regions of the head, legs, and arms. M. varians was the second most frequent Micrococcus isolated. M. lylae, M. sedentarius, M. roseus, M. kristinae, and M. nishinomiyaensis were only occasionally isolated from skin. M. lylae was most frequently isolated during the colder months of the years. PMID:810086

Kloos, W E; Musselwhite, M S

1975-09-01

137

Distribution and Persistence of Staphylococcus and Micrococcus Species and Other Aerobic Bacteria on Human Skin1  

PubMed Central

The distribution of Staphylococcus and Micrococcus species and associated coryneform bacteria, Acinetobacter, Klebsiella, Enterobacter, Bacillus, and Streptomyces on skin was determined during October 1971 from samples collected on persons living in North Carolina and New Jersey. Persistence of these organisms on skin was estimated in temporal studies conducted during the period from June 1971 to June 1972 on persons living in North Carolina. Staphylococci and coryneforms were the most predominant and persistent bacteria isolated from the nares and axillae. Staphylococci, coryneforms, micrococci, and Bacillus were the most predominant and persistent bacteria isolated from the head, legs, and arms. Acinetobacters were most frequently isolated during the warmer months of the years. Staphylococcus aureus and S. epidermidis were the most predominant and persistent staphylococci isolated from the nares, whereas S. epidermidis and S. hominis were the most predominant and persistent staphylococci isolated from the axillae, head, legs, and arms. S. capitis was often isolated from the head and arms and S. haemolyticus was often isolated from the head, legs, and arms. S. simulans, S. xylosus, S. cohnii, S. saprophyticus, S. warneri, and an unclassified coagulase-positive species were only occasionally isolated from skin. Micrococcus luteus was the most predominant and persistent Micrococcus isolated from skin and preferred regions of the head, legs, and arms. M. varians was the second most frequent Micrococcus isolated. M. lylae, M. sedentarius, M. roseus, M. kristinae, and M. nishinomiyaensis were only occasionally isolated from skin. M. lylae was most frequently isolated during the colder months of the years.

Kloos, Wesley E.; Musselwhite, Margaret S.

1975-01-01

138

Evaluation of an optical microbiological method for rapidly estimating populations of aerobic bacteria, coliforms, and Escherichia coli from ground pork.  

PubMed

The BioSys optical methods for estimating populations of aerobic bacteria, coliforms, and Escherichia coli from ground pork were evaluated. Ground pork samples were analyzed immediately, after temperature abuse at 25 degrees C for various periods of time, or after temperature abuse and dilution by mixing with pork that was prepared by grinding whole muscles that had the outer portion excised using a sterile scalpel. Each ground pork sample was tested using standard methods such as aerobic plate counts (APC), violet red bile (VRB) agar plate counts (coliforms), and three-tube most probable numbers (MPN--E. coli). Each sample was tested using the BioSys for total viable counts (TVC) by placing 2 ml of ground pork homogenate (25 g into 225 ml of sterile 1% buffered peptone water) into 8 ml of nutrient medium containing brom-cresol purple in a test vial and monitoring at 35 degrees C. Coliforms were enumerated by placing 5 ml of ground pork homogenate into 5 ml of coliform medium (CM) in a test vial and monitoring at 35 degrees C. E. coli were enumerated by placing 5 ml of ground pork homogenate into 5 ml of double-strength CM with 2% dextrose in a test vial and monitoring at 42 degrees C. The correlation coefficients for the regression lines comparing APC to BioSys TVC detection times (DT), VRB to BioSys coliform DT, and MPN to BioSys E. coli DT were -0.95, -0.94, and -0.93, and the line equations were logl0 CFU/ml = 8.94 - 0.40(DT), log10 CFU/ml = 8.77 - 0.43(DT), and log10 CFU/ml = 8.96 - 0.81(DT), respectively. These methods may allow pork producers to monitor equipment surfaces and products in less than 16 h and obtain microbiological results prior to shipment. PMID:11347998

Russell, S M

2001-05-01

139

Distribution of epiphytic bacteria on olive leaves and the influence of leaf age and sampling time  

Microsoft Academic Search

Mesophilic heterotrophic, aerobic or facultatively anaerobic bacteria that grow on yeast tryptone glucose extract agar were\\u000a isolated from the surface of olive leaves of 3 or 4 different ages in January, April, July, and October from 1984 to 1989.\\u000a Unweighted average linkage cluster analysis on either the Jaccard coefficient or the simple matching coefficient recovered\\u000a 1,701 representative strains in 32

G. L. Ercolani

1991-01-01

140

Spore-forming bacteria in commercial cooked, pasteurised and chilled vegetable purées  

Microsoft Academic Search

In commercial purées of broccoli, carrot, courgette, leek, potato and split pea, pasteurized in their final packaging and analysed at two periods, Bacillus spp. were the dominant aerobic mesophilic bacteria (AMB). Initial numbers were generally lower than 2 log cfu g?1. They increased up to 6–8 log cfu g?1after about 20 days of storage at 10°C. At 4°C, numbers of

Frédéric Carlin; Marie-Hélène Guinebretiere; Caroline Choma; Roselyne Pasqualini; Agnès Braconnier; Christophe Nguyen-the

2000-01-01

141

Complete Genome Sequence of the Aerobic Marine Methanotroph Methylomonas methanica MC09  

SciTech Connect

Methylomonas methanica MC09 is a mesophilic, halotolerant, aerobic, methanotrophic member of the Gammaproteobacteria, isolated from coastal seawater. Here we present the complete genome sequence of this strain, the first available from an aerobic marine methanotroph.

Boden, Rich [University of Warwick, UK; Cunliffe, Michael [University of Warwick, UK; Scanlan, Julie [University of Warwick, UK; Moussard, Helene [University of Warwick, UK; Kits, K. Dimitri [University of Alberta, Edmondton, Canada; Klotz, Martin G [University of Louisville, Louisville; Jetten, MSM [Radboud University Nijmegen, The Netherlands; Vuilleumier, Stephane [University of Strasbourg; Han, James [U.S. Department of Energy, Joint Genome Institute; Peters, Lin [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Teshima, Hazuki [Los Alamos National Laboratory (LANL); Tapia, Roxanne [Los Alamos National Laboratory (LANL); Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Stein, Lisa Y. [University of Alberta, Edmondton, Canada; Murrell, Collin [University of Warwick, UK

2011-01-01

142

Aerobic respiration metabolism in lactic acid bacteria and uses in biotechnology.  

PubMed

The lactic acid bacteria (LAB) are essential for food fermentations and their impact on gut physiology and health is under active exploration. In addition to their well-studied fermentation metabolism, many species belonging to this heterogeneous group are genetically equipped for respiration metabolism. In LAB, respiration is activated by exogenous heme, and for some species, heme and menaquinone. Respiration metabolism increases growth yield and improves fitness. In this review, we aim to present the basics of respiration metabolism in LAB, its genetic requirements, and the dramatic physiological changes it engenders. We address the question of how LAB acquired the genetic equipment for respiration. We present at length how respiration can be used advantageously in an industrial setting, both in the context of food-related technologies and in novel potential applications. PMID:22385163

Pedersen, Martin B; Gaudu, Philippe; Lechardeur, Delphine; Petit, Marie-Agnès; Gruss, Alexandra

2011-11-07

143

Hexavalent chromium reduction by aerobic heterotrophic bacteria indigenous to chromite mine overburden  

PubMed Central

Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gram-negative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2–8 mM) when tested in peptone yeast extract glucose agar medium. Isolates (92) tolerating 2 mM chromium exhibited different degrees of Cr+6 reducing activity in chemically defined Vogel Bonner (VB) broth and complex KSC medium. Three potent isolates, two belonging to Arthrobacter spp. and one to Pseudomonas sp. were able to reduce more than 50 and 80% of 2 mM chromium in defined and complex media respectively. Along with Cr+6 (MIC 8.6–17.8 mM), the isolates showed tolerance to Ni+2, Fe+3, Cu+2 and Co+2 but were extremely sensitive to Hg+2 followed by Cd+2, Mn+2 and Zn+2. In addition, they were resistant to antibiotics like penicillin, methicillin, ampicillin, neomycin and polymyxin B. During growth under shake-flask conditions, Arthrobacter SUK 1201 and SUK 1205 showed 100% reduction of 2 mM Cr+6 in KSC medium with simultaneous formation of insoluble precipitates of chromium salts. Both the isolates were also equally capable of completely reducing the Cr+6 present in mine seepage when grown in mine seepage supplemented with VB concentrate.

Dey, Satarupa; Paul, A.K.

2013-01-01

144

Hexavalent chromium reduction by aerobic heterotrophic bacteria indigenous to chromite mine overburden.  

PubMed

Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gram-negative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2-8 mM) when tested in peptone yeast extract glucose agar medium. Isolates (92) tolerating 2 mM chromium exhibited different degrees of Cr(+6) reducing activity in chemically defined Vogel Bonner (VB) broth and complex KSC medium. Three potent isolates, two belonging to Arthrobacter spp. and one to Pseudomonas sp. were able to reduce more than 50 and 80% of 2 mM chromium in defined and complex media respectively. Along with Cr(+6) (MIC 8.6-17.8 mM), the isolates showed tolerance to Ni(+2), Fe(+3), Cu(+2) and Co(+2) but were extremely sensitive to Hg(+2) followed by Cd(+2), Mn(+2) and Zn(+2). In addition, they were resistant to antibiotics like penicillin, methicillin, ampicillin, neomycin and polymyxin B. During growth under shake-flask conditions, Arthrobacter SUK 1201 and SUK 1205 showed 100% reduction of 2 mM Cr(+6) in KSC medium with simultaneous formation of insoluble precipitates of chromium salts. Both the isolates were also equally capable of completely reducing the Cr(+6) present in mine seepage when grown in mine seepage supplemented with VB concentrate. PMID:24159321

Dey, Satarupa; Paul, A K

2013-05-31

145

Isolation and characterization of potential aerobic bacteria capable for pyridine degradation in presence of picoline, phenol and formaldehyde as co-pollutants  

Microsoft Academic Search

Pyridine, heterocyclic aromatic compound is known to be toxic, carcinogenic and teratogenic to several living organisms. In\\u000a this study, two aerobic bacteria ITRCEM1 and ITRCEM2 capable for pyridine degradation were isolated and characterized as Bacillus cereus (DQ435020) and Alcaligenes faecalis (DQ435021), respectively. For pyridine degradation, mixed bacterial culture was found more effective compared to axenic culture\\u000a ITRCEM1 and ITRCEM2 degrading

Ram Chandra; Ram Naresh Bharagava; Atya Kapley; Hemant J. Purohit

2009-01-01

146

Aerobic degradation of di- and trichlorobenzenes by two bacteria isolated from polluted tropical soils.  

PubMed

Two polychlorinated biphenyl (PCBs)-degrading bacteria were isolated by traditional enrichment technique from electrical transformer fluid (Askarel)-contaminated soils in Lagos, Nigeria. They were classified and identified as Enterobacter sp. SA-2 and Pseudomonas sp. SA-6 on the basis of 16S rRNA gene analysis, in addition to standard cultural and biochemical techniques. The strains were able to grow extensively on dichloro- and trichlorobenzenes. Although they failed to grow on tetrachlorobenzenes, monochloro- and dichlorobenzoic acids, they were able to utilize all monochlorobiphenyls, and some dichlorobiphenyls as sole sources of carbon and energy. The effect of incubation with axenic cultures on the degradation of 0.9 mM 1,4-dichlorobenzene, 0.44 mM 1,2,3- and 0.43 mM 1,3,5-trichlorobenzene in mineral salts medium was studied. Approximately, 80-90% of these xenobiotics were degraded in 200 h, concomitant with cell increase of up to three orders of magnitude, while generation times ranged significantly (P<0.05) from 17-32 h. Catechol 1,2-dioxygenase and catechol 2,3-dioxygenase activities were detected in crude cell-free extracts of cultures pre-grown with benzoate, with the latter enzyme exhibiting a slightly higher activity (0.15-0.17 micromolmin(-1) mg of protein(-1)) with catechol, suggesting that the meta-cleavage pathway is the most readily available catabolic route in the SA strains. The wider substrate specificity of these tropical isolates may help in assessing natural detoxification processes and in designing bioremediation and bioaugmentation methods. PMID:16962633

Adebusoye, Sunday A; Picardal, Flynn W; Ilori, Matthew O; Amund, Olukayode O; Fuqua, Clay; Grindle, Nathan

2006-09-08

147

Aerobic Hetrotrophic Bacterial Populations of Sewage and Activated Sludge. II. Method of Characterization of Activated Sludge Bacteria.  

National Technical Information Service (NTIS)

The replica-plating technique and Lochhead's nutritional method were combined in exploratory experiments to test their feasibility as useful means for characterizing the aerobic heterotrophic flora of activated sludge and to minimize the burdensome proces...

T. B. S. Prakasam N. C. Dondero

1967-01-01

148

Alkalimonas amylolytica gen. nov., sp. nov., and Alkalimonas delamerensis gen. nov., sp. nov., novel alkaliphilic bacteria from soda lakes in China and East Africa  

Microsoft Academic Search

Two related novel alkaliphilic and slightly halophilic bacteria are described. They are strain N10 from Lake Chahannor in China and strain 1E1 from Lake Elmenteita in East Africa. Both strains are strictly aerobic, heterotrophic, alkaliphilic, mesophilic, and require NaCl for growth. The optimal conditions for growth were at pH 10–10.5 and 2–3% (w\\/v) NaCl. Cells of both strains were Gram-negative,

Yanhe Ma; Yanfen Xue; William D. Grant; Nadine C. Collins; Andrew W. Duckworth; Robert P. van Steenbergen; Brian E. Jones

2004-01-01

149

Mesophilic cellulolytic clostridia from freshwater environments.  

PubMed

Eight strains of obligately anaerobic, mesophilic, cellulolytic bacteria were isolated from mud of freshwater environments. The isolates (C strains) were rod-shaped, gram negative, and formed terminal spherical to oval spores that swelled the sporangium. The guanine plus cytosine content of the DNA of the C strains ranged from 30.7 to 33.2 mol% (midpoint of thermal denaturation). The C strains fermented cellulose with formation primarily of acetate, ethanol, CO(2), and H(2). Reducing sugars accumulated in the supernatant fluid of cultures which initially contained >/=0.4% (wt/vol) cellulose. The C strains resembled Clostridium cellobioparum in some phenotypic characteristics and Clostridium papyrosolvens in others, but they were not identical to either of these species. The C strains differed from thermophilic cellulolytic clostridia (e.g., Clostridium thermocellum) not only in growth temperature range but also because they fermented xylan and five-carbon products of plant polysaccharide hydrolysis such as d-xylose and l-arabinose. At 40 degrees C, cellulose was degraded by cellulolytic mesophilic cells (strain C7) at a rate comparable to that at which C. thermocellum degrades cellulose at 60 degrees C. Substrate utilization and growth temperature data indicated that the C strains contribute to the anaerobic breakdown of plant polymers in the environments they inhabit. PMID:16346388

Leschine, S B; Canale-Parola, E

1983-09-01

150

Interphase Between Bacterial Mesophilism and Thermophilism.  

National Technical Information Service (NTIS)

The temperature interphase between bacterial mesophilism and thermophilism has been identified as 46 C to 48 C. Facultative thermophiles growing in the mesophilic range require a brief period of adaptation at interphase temperatures before gaining the cap...

H. T. Bausum T. S. Matney

1964-01-01

151

Kinetic evaluation and performance of a mesophilic anaerobic contact reactor treating medium-strength food-processing wastewater  

Microsoft Academic Search

High rate mesophilic anaerobic contact reactors (MACR) represent a proven sustainable technology for a wide range of different industrial effluents. These reactors demonstrate quite similar features to their aerobic counterparts, activated sludge systems. A lab-scale high rate mesophilic anaerobic contact reactor was operated with wastewater originated from a potato-processing plant, at six different loading rates of 1.1–5g COD\\/L per day.

E. ?entürk; M. ?nce; G. Onkal Engin

2010-01-01

152

Comparative analysis of the diversity of aerobic spore-forming bacteria in raw milk from organic and conventional dairy farms  

Microsoft Academic Search

Bacterial contamination of raw milk can originate from different sources: air, milking equipment, feed, soil, faeces and grass. It is hypothesized that differences in feeding and housing strategies of cows may influence the microbial quality of milk. This assumption was investigated through comparison of the aerobic spore-forming flora in milk from organic and conventional dairy farms. Laboratory pasteurized milk samples

An Coorevits; Valerie De Jonghe; Joachim Vandroemme; Rieka Reekmans; Jeroen Heyrman; Winy Messens; Paul De Vos; Marc Heyndrickx

2008-01-01

153

Mesophilic lactobacilli in Fiore Sardo cheese: PCR-identification and evolution during cheese ripening  

Microsoft Academic Search

The mesophilic lactobacilli colonizing Fiore Sardo ewe's milk cheese were characterized. They seemed to be the dominant non-starter lactic acid bacteria composing its natural microflora, with a viable cell number varying from 105CFUg?1 (1-day-old cheese) to 108CFUg?1 (30-day-old cheese) and then slowly decreasing up to 104CFUg?1 after 7 months’ ripening. Considering the relevance of mesophilic lactobacilli in affecting the cheese

Luisa Mannu; Roberta Comunian; Maria Francesca Scintu

2000-01-01

154

Isolation and characterization of aerobic culturable arsenic-resistant bacteria from surfacewater and groundwater of Rautahat District, Nepal  

Microsoft Academic Search

Arsenic (As) contamination of groundwater is a serious Environmental Health Management issue of drinking water sources especially in Terai region of Nepal. Many studies have reported that due to natural abundance of arsenic in the environment, various bacteria have developed different resistance mechanisms for arsenic compound. In this study, the culturable arsenic-resistant bacteria indigenous to surfacewater as well as groundwater

S. Shakya; B. Pradhan; L. Smith; J. Shrestha; S. Tuladhar

155

Iodide Accumulation by Aerobic Bacteria Isolated from Subsurface Sediments of a 129I-Contaminated Aquifer at the Savannah River Site, South Carolina ?  

PubMed Central

129I is of major concern because of its mobility in the environment, excessive inventory, toxicity (it accumulates in the thyroid), and long half-life (?16 million years). The aim of this study was to determine if bacteria from a 129I-contaminated oxic aquifer at the F area of the U.S. Department of Energy's Savannah River Site, SC, could accumulate iodide at environmentally relevant concentrations (0.1 ?M I?). Iodide accumulation capability was found in 3 out of 136 aerobic bacterial strains isolated from the F area that were closely related to Streptomyces/Kitasatospora spp., Bacillus mycoides, and Ralstonia/Cupriavidus spp. Two previously described iodide-accumulating marine strains, a Flexibacter aggregans strain and an Arenibacter troitsensis strain, accumulated 2 to 50% total iodide (0.1 ?M), whereas the F-area strains accumulated just 0.2 to 2.0%. Iodide accumulation by FA-30 was stimulated by the addition of H2O2, was not inhibited by chloride ions (27 mM), did not exhibit substrate saturation kinetics with regard to I? concentration (up to 10 ?M I?), and increased at pH values of <6. Overall, the data indicate that I? accumulation likely results from electrophilic substitution of cellular organic molecules. This study demonstrates that readily culturable, aerobic bacteria of the F-area aquifer do not accumulate significant amounts of iodide; however, this mechanism may contribute to the long-term fate and transport of 129I and to the biogeochemical cycling of iodine over geologic time.

Li, Hsiu-Ping; Brinkmeyer, Robin; Jones, Whitney L.; Zhang, Saijin; Xu, Chen; Schwehr, Kathy A.; Santschi, Peter H.; Kaplan, Daniel I.; Yeager, Chris M.

2011-01-01

156

Multicenter evaluation of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of Gram-positive aerobic bacteria.  

PubMed

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) is gaining momentum as a tool for bacterial identification in the clinical microbiology laboratory. Compared with conventional methods, this technology can more readily and conveniently identify a wide range of organisms. Here, we report the findings from a multicenter study to evaluate the Vitek MS v2.0 system (bioMérieux, Inc.) for the identification of aerobic Gram-positive bacteria. A total of 1,146 unique isolates, representing 13 genera and 42 species, were analyzed, and results were compared to those obtained by nucleic acid sequence-based identification as the reference method. For 1,063 of 1,146 isolates (92.8%), the Vitek MS provided a single identification that was accurate to the species level. For an additional 31 isolates (2.7%), multiple possible identifications were provided, all correct at the genus level. Mixed-genus or single-choice incorrect identifications were provided for 18 isolates (1.6%). Although no identification was obtained for 33 isolates (2.9%), there was no specific bacterial species for which the Vitek MS consistently failed to provide identification. In a subset of 463 isolates representing commonly encountered important pathogens, 95% were accurately identified to the species level and there were no misidentifications. Also, in all but one instance, the Vitek MS correctly differentiated Streptococcus pneumoniae from other viridans group streptococci. The findings demonstrate that the Vitek MS system is highly accurate for the identification of Gram-positive aerobic bacteria in the clinical laboratory setting. PMID:23658261

Rychert, Jenna; Burnham, Carey-Ann D; Bythrow, Maureen; Garner, Omai B; Ginocchio, Christine C; Jennemann, Rebecca; Lewinski, Michael A; Manji, Ryhana; Mochon, A Brian; Procop, Gary W; Richter, Sandra S; Sercia, Linda; Westblade, Lars F; Ferraro, Mary Jane; Branda, John A

2013-05-08

157

Evaluation of the Effects of Storage in Two Different Swab Fabrics and under Three Different Transport Conditions on Recovery of Aerobic and Anaerobic Bacteria  

Microsoft Academic Search

Recovery of six anaerobic and five aerobic pathogens from viscose swabs and polyurethane swabs (Culturette EZ) was evaluated quantitatively, and transport in aerobic dry tubes, aerobic Amies transport medium (Transwab), and anaerobic universal transport medium (Port-a-Cul) was compared. The Culturette EZ in aerobic dry tubes gave the highest recovery levels. Data obtained with clinical specimens confirmed these results.

E. Roelofsen; M. van Leeuwen; G. J. Meijer-Severs; M. H. F. Wilkinson; J. E. Degener

1999-01-01

158

Evaluation of the effects of storage in two different swab fabrics and under three different transport conditions on recovery of aerobic and anaerobic bacteria.  

PubMed

Recovery of six anaerobic and five aerobic pathogens from viscose swabs and polyurethane swabs (Culturette EZ) was evaluated quantitatively, and transport in aerobic dry tubes, aerobic Amies transport medium (Transwab), and anaerobic universal transport medium (Port-a-Cul) was compared. The Culturette EZ in aerobic dry tubes gave the highest recovery levels. Data obtained with clinical specimens confirmed these results. PMID:10449502

Roelofsen, E; van Leeuwen, M; Meijer-Severs, G J; Wilkinson, M H; Degener, J E

1999-09-01

159

Aerobic Heterotrophic Bacteria Indigenous to pH 2.8 Acid Mine Water: Microscopic Examination of Acid Streamers  

PubMed Central

“Acid streamers” found in acid coal mine drainage consist of bacteria trapped within an extracellular fibrillar polymer network. Inorganic compounds also precipitate within the polymer network. Several bacteria which appear to be different and are presumed to be different species are associated in the slimy mass of the “acid streamers.” The “streamers” contain individual microcolonies or microcosms that can be recognized by a selective polysaccharide stain, which suggests that the slime streamer is a conglomeration of polymers produced by more than one species. Images

Dugan, Patrick R.; MacMillan, Carol B.; Pfister, Robert M.

1970-01-01

160

Isolations of aerobic bacteria from wild desert bighorn sheep (Ovis canadensis nelsoni and O. c. mexicana) in Arizona.  

PubMed

Nasal, pharyngeal, cervical and vaginal swab specimens were obtained from 74 desert bighorn sheep for the purpose of investigating the normal aerobic bacterial flora of wild sheep. A total of 281 isolates was obtained and identified by standard microbiologic tests. One hundred seven of these isolates were gram positive and included Bacillus sp. (36%), Staphylococcus epidermidis (8%), S. aureus (4%), Corynebacterium sp. (diphtheroids, 4%), and Streptococcus sp. (48%). gram negative isolates totaled 174 and included Neisseria sp. (18%), Citrobacter sp. (3%), Enterobacter sp. (2%), Escherichia coli (2%), Proteus sp. (2%) and non-fermentative bacilli (NFB) (73%). Of the NFB isolates, Pseudomonas sp. (25%), Acinetobacter sp. (18%), Moraxella sp. (15%) were identified. PMID:6887449

Marshall, M M; Songer, J G; Chilelli, C J; deVos, J C

1983-04-01

161

Effect of Time and Sand Abrasion on Recovery of Aerobic Bacteria, Escherichia coli, and Coliforms from Broiler Carcasses  

Technology Transfer Automated Retrieval System (TEKTRAN)

An experiment was conducted to determine the effect of rinse time and a sand abrasion on bacteria from whole broiler carcass rinses (WCR). Twelve eviscerated broiler carcasses were obtained from a commercial processing plant prior to chilling. Six carcasses were rinsed in 400 mL of 2.0% buffered pe...

162

Inactivation of Enteric Pathogens during Aerobic Digestion of Wastewater Sludge.  

National Technical Information Service (NTIS)

The effects of aerobic and anaerobic digestion on enteric viruses, enteric bacteria, total aerobic bacteria, and intestinal parasites were studied under laboratory and field conditions. Under laboratory conditions, the temperature of the sludge digestion ...

S. R. Farrah G. Bitton S. G. Zam

1986-01-01

163

INACTIVATION OF ENTERIC PATHOGENS DURING AEROBIC DIGESTION OF WASTEWATER SLUDGE  

EPA Science Inventory

The effects of aerobic and anaerobic digestion on enteric viruses, enteric bacteria, total aerobic bacteria, and intestinal parasites were studied under laboratory and field conditions. Under laboratory conditions, the temperature of the sludge digestion was the major factor infl...

164

Novel cellulose-binding domains, NodB homologues and conserved modular architecture in xylanases from the aerobic soil bacteria Pseudomonas fluorescens subsp. cellulosa and Cellvibrio mixtus.  

PubMed Central

To test the hypothesis that selective pressure has led to the retention of cellulose-binding domains (CBDs) by hemicellulase enzymes from aerobic bacteria, four new xylanase (xyn) genes from two cellulolytic soil bacteria, Pseudomonas fluorescens subsp. cellulosa and Cellvibrio mixtus, have been isolated and sequenced. Pseudomonas genes xynE and xynF encoded modular xylanases (XYLE and XYLF) with predicted M(r) values of 68,600 and 65000 respectively. XYLE contained a glycosyl hydrolase family 11 catalytic domain at its N-terminus, followed by three other domains; the second of these exhibited sequence identity with NodB from rhizobia. The C-terminal domain (40 residues) exhibited significant sequence identity with a non-catalytic domain of previously unknown function, conserved in all the cellulases and one of the hemicellulases previously characterized from the pseudomonad, and was shown to function as a CBD when fused to the reporter protein glutathione-S-transferase. XYLF contained a C-terminal glycosyl hydrolase family 10 catalytic domain and a novel CBD at its N-terminus. C. mixtus genes xynA and xynB exhibited substantial sequence identity with xynE and xynF respectively, and encoded modular xylanases with the same molecular architecture and, by inference, the same functional properties. In the absence of extensive cross-hybridization between other multiple cel (cellulase) and xyn genes from P. fluorescens subsp. cellulosa and genomic DNA from C. mixtus, similarity between the two pairs of xylanases may indicate a recent transfer of genes between the two bacteria. Images Figure 1 Figure 4

Millward-Sadler, S J; Davidson, K; Hazlewood, G P; Black, G W; Gilbert, H J; Clarke, J H

1995-01-01

165

Diversity and Function of Chloroflexus-Like Bacteria in a Hypersaline Microbial Mat: Phylogenetic Characterization and Impact on Aerobic Respiration  

Microsoft Academic Search

Received 31 October 2006\\/Accepted 11 April 2007 We studied the diversity of Chloroflexus-like bacteria (CLB) in a hypersaline phototrophic microbial mat and assayed their near-infrared (NIR) light-dependent oxygen respiration rates. PCR with primers that were reported to specifically target the 16S rRNA gene from members of the phylum Chloroflexi resulted in the recovery of 49 sequences and 16 phylotypes (sequences

Ami Bachar; Enoma Omoregie; Rutger de Wit; Henk M. Jonkers

2007-01-01

166

Anaerobically grown Thauera aromatica , Desulfococcus multivorans , Geobacter sulfurreducens are more sensitive towards organic solvents than aerobic bacteria  

Microsoft Academic Search

The effect of seven important pollutants and three representative organic solvents on growth of Thauera aromatica K172, as reference strain for nitrate-reducing anaerobic bacteria, was investigated. Toxicity in form of the effective concentrations\\u000a (EC50) that led to 50% growth inhibition of potential organic pollutants such as BTEX (benzene, toluene, ethylbenzene, and\\u000a xylene), chlorinated phenols and aliphatic alcohols on cells was

Ilka Duldhardt; Ivonne Nijenhuis; Frieder Schauer; Hermann J. Heipieper

2007-01-01

167

Isolation and characterization of aerobic culturable arsenic-resistant bacteria from surfacewater and groundwater of Rautahat District, Nepal.  

PubMed

Arsenic (As) contamination of groundwater is a serious Environmental Health Management issue of drinking water sources especially in Terai region of Nepal. Many studies have reported that due to natural abundance of arsenic in the environment, various bacteria have developed different resistance mechanisms for arsenic compound. In this study, the culturable arsenic-resistant bacteria indigenous to surfacewater as well as groundwater from Rautahat District of Nepal were randomly isolated by standard plate count method on the basis of viable growth on plate count agar amended with arsenate ranging from 0, 0.5, 10, 40, 80 to 160 milligram per liter (mg/l). With respect to the morphological and biochemical tests, nine morphologically distinct potent arsenate tolerant bacteria showed relatedness with Micrococcus varians, Micrococcus roseus, Micrococcus luteus, Pseudomonas maltophilia, Pseudomonas sp., Vibrio parahaemolyticus, Bacillus cereus, Bacillus smithii 1 and Bacillus smithii 2. The isolates were capable of tolerating more than 1000 mg/l of arsenate and 749 mg/l of arsenite. Likewise, bioaccumulation capability was highest with M. roseus (85.61%) and the least with B. smithii (47.88%) indicating the potential of the organisms in arsenic resistance and most probably in bioremediation. PMID:21868146

Shakya, S; Pradhan, B; Smith, L; Shrestha, J; Tuladhar, S

2011-08-24

168

Prevalence of aerobic and anaerobic uterine bacteria during peripartum period in normal and dystocia-affected buffaloes.  

PubMed

Parturition complications predispose establishment of uterine infections, which in turn affect subsequent fertility. The aim of present study was to characterize and compare the type of bacterial flora prevalent within the uterine lumen of dystocia-affected buffaloes and compare them with the normally calving buffaloes. The study was conducted on 40 buffaloes; of which 10 calved normally (Group I) and 30 were treated for dystocia (Group II). Bacteriological examination was performed using uterine swabs, which were collected before delivery, immediately after delivery and day's 24-60 postpartum. A total of 30 uterine swabs from Group I and 79 swabs from Group II were collected, of which 19 (63.3%) and 71 (89.9%) yielded significant bacterial growth, respectively. A total of 205 isolates belonging to 10 different genera of bacteria were identified, 8 facultative anaerobes and 2 obligate anaerobes. In Group II, 91.6% of the bacteria positive swabs (n = 71) yielded mixed cultures, whereas the remainder being pure cultures. In contrast, 89.5% of the bacteria positive swabs of Group I (n = 19) yielded pure cultures. Mixed infections comprised mostly Arcanobacter (Actinomyces) pyogenes together with obligate anaerobes, Fusobacterium spp. and Bacteroides spp. In Group II, the frequency of incidental and coliform group bacteria was highest at the time of parturition, i.e., before and immediately after delivery, and decreased to nil during the 24-60-day postpartum period. However, in Group I, the incidental and coliform group of bacteria present at the time of parturition apparently persisted beyond the period when uterine involution is complete. The frequency of obligate anaerobes and A. pyogenes at the time of parturition was nil in the Group I while they predominated in dystocia-affected buffaloes (Group II). During the postpartum period of 24-60 days, the frequency of both obligate anaerobes and A. pyogenes increased significantly in Group II, whereas in Group I, only occasional isolates were obtained. To conclude, at the time of calving the prevalence of obligate anaerobes and A. pyogenes occurring in combination was highest in dystocia-affected buffaloes, and further increased in the postpartum period suggesting that these infections act synergistically. PMID:16143213

Jadon, R S; Dhaliwal, G S; Jand, S K

2005-09-01

169

Central Role of Dynamic Tidal Biofilms Dominated by Aerobic Hydrocarbonoclastic Bacteria and Diatoms in the Biodegradation of Hydrocarbons in Coastal Mudflats  

PubMed Central

Mudflats and salt marshes are habitats at the interface of aquatic and terrestrial systems that provide valuable services to ecosystems. Therefore, it is important to determine how catastrophic incidents, such as oil spills, influence the microbial communities in sediment that are pivotal to the function of the ecosystem and to identify the oil-degrading microbes that mitigate damage to the ecosystem. In this study, an oil spill was simulated by use of a tidal chamber containing intact diatom-dominated sediment cores from a temperate mudflat. Changes in the composition of bacteria and diatoms from both the sediment and tidal biofilms that had detached from the sediment surface were monitored as a function of hydrocarbon removal. The hydrocarbon concentration in the upper 1.5 cm of sediments decreased by 78% over 21 days, with at least 60% being attributed to biodegradation. Most phylotypes were minimally perturbed by the addition of oil, but at day 21, there was a 10-fold increase in the amount of cyanobacteria in the oiled sediment. Throughout the experiment, phylotypes associated with the aerobic degradation of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs) (Cycloclasticus) and alkanes (Alcanivorax, Oleibacter, and Oceanospirillales strain ME113), substantively increased in oiled mesocosms, collectively representing 2% of the pyrosequences in the oiled sediments at day 21. Tidal biofilms from oiled cores at day 22, however, consisted mostly of phylotypes related to Alcanivorax borkumensis (49% of clones), Oceanospirillales strain ME113 (11% of clones), and diatoms (14% of clones). Thus, aerobic hydrocarbon biodegradation is most likely to be the main mechanism of attenuation of crude oil in the early weeks of an oil spill, with tidal biofilms representing zones of high hydrocarbon-degrading activity.

Coulon, Frederic; Chronopoulou, Panagiota-Myrsini; Fahy, Anne; Paisse, Sandrine; Goni-Urriza, Marisol; Peperzak, Louis; Acuna Alvarez, Laura; McKew, Boyd A.; Brussaard, Corina P. D.; Underwood, Graham J. C.; Timmis, Kenneth N.; Duran, Robert

2012-01-01

170

Evaluation of the Removal of Indicator Bacteria from Domestic Sludge Processed by Autothermal Thermophilic Aerobic Digestion (ATAD)  

PubMed Central

The degradation of sludge solids in an insulated reactor during Autothermal Thermophilic Aerobic Digestion (ATAD) processing results in auto-heating, thermal treatment and total solids reduction, however, the ability to eliminate pathogenic organisms has not been analysed under large scale process conditions. We evaluated the ATAD process over a period of one year in a two stage, full scale Irish ATAD plant established in Killarney and treating mixed primary and secondary sludge, by examining the sludge microbiologically at various stages during and following ATAD processing to determine its ability to eliminate indicator organisms. Salmonella spp. (pathogen) and fecal-coliform (indicator) densities were well below the limits used to validate class A biosolids in the final product. Enteric pathogens present at inlet were deactivated during the ATAD process and were not detected in the final product using both traditional microbial culture and molecular phylogenetic techniques. A high DNase activity was detected in the bulk sludge during the thermophilic digestion stage which may be responsible for the rapid turn over of DNA from lysed cells and the removal of mobile DNA. These results offer assurance for the safe use of ATAD sludge as a soil supplement following processing.

Piterina, Anna V.; Bartlett, John; Pembroke, Tony J.

2010-01-01

171

Aerobic biodegradation of methyl tert-butyl ether by aquifer bacteria from leaking underground storage tank sites.  

PubMed

The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observed for sediments from the other sites after 75 days. For sediments in which MTBE was consumed, 43 to 54% of added [U-(14)C]MTBE was mineralized to (14)CO(2). Molecular phylogenetic analyses of these sediments indicated the enrichment of species closely related to a known MTBE-degrading bacterium, strain PM1. At only one site, the presence of water-soluble gasoline components significantly inhibited MTBE degradation and led to a more pronounced accumulation of the metabolite tert-butyl alcohol. Overall, these results suggest that the effects of oxygen and water-soluble gasoline components on in situ MTBE degradation will vary from site to site and that phylogenetic analysis may be a promising predictor of MTBE biodegradation potential. PMID:11722940

Kane, S R; Beller, H R; Legler, T C; Koester, C J; Pinkart, H C; Halden, R U; Happel, A M

2001-12-01

172

Aerobic Biodegradation of Methyl tert-Butyl Ether by Aquifer Bacteria from Leaking Underground Storage Tank Sites  

PubMed Central

The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observed for sediments from the other sites after 75 days. For sediments in which MTBE was consumed, 43 to 54% of added [U-14C]MTBE was mineralized to 14CO2. Molecular phylogenetic analyses of these sediments indicated the enrichment of species closely related to a known MTBE-degrading bacterium, strain PM1. At only one site, the presence of water-soluble gasoline components significantly inhibited MTBE degradation and led to a more pronounced accumulation of the metabolite tert-butyl alcohol. Overall, these results suggest that the effects of oxygen and water-soluble gasoline components on in situ MTBE degradation will vary from site to site and that phylogenetic analysis may be a promising predictor of MTBE biodegradation potential.

Kane, S. R.; Beller, H. R.; Legler, T. C.; Koester, C. J.; Pinkart, H. C.; Halden, R. U.; Happel, A. M.

2001-01-01

173

DNA topology and the thermal stress response, a tale from mesophiles and hyperthermophiles  

Microsoft Academic Search

Summary During heat shock and cold shock, plasmid DNA super- coiling changes transiently both in mesophilic bacteria and in hyperthermophilic archaea, despite a different overall topology (negative supercoiling versus relaxa- tion to positive supercoiling). Transient changes in DNA supercoiling might be essential to generate the stress response, but they could also be a consequence of the physical effects of temperature

Patrick Forterre

2000-01-01

174

Combined thermophilic aerobic process and conventional anaerobic digestion: effect on sludge biodegradation and methane production.  

PubMed

The efficiency of hyper-thermophilic (65 degrees Celsius) aerobic process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency. PMID:19959355

Dumas, C; Perez, S; Paul, E; Lefebvre, X

2009-12-02

175

Susceptibility to antibiotics of aerobic bacteria isolated from community acquired secondary peritonitis in children: therapeutic guidelines might not always fit with and everyday experience.  

PubMed

Appendicitis is a frequent clinical condition in normal children that may be complicated by community-acquired secondary peritonitis (CASP). We evaluated the potential efficacy of different drugs for initial treatment of this condition, as recommended by recent Consensus Conference and Guidelines for paediatric patients. Susceptibility to ampicillin-sulbactam, ertapenem, gentamycin, piperacillin, piperacillin-tazobactam, vancomycin, and teicoplanin was evaluated according to EUCST 2012 recommendations in aerobic bacteria isolated from peritoneal fluid in CASP diagnosed from 2005 to 2011 at 'Istituto Giannina Gaslini', Genoa, Italy. A total of 114 strains were analysed: 83 E. coli, 15 P. aeruginosa, 6 Enterococci, and 10 other Gram-negatives. Resistance to ampicillin-sulbactam was detected in 37% of strains, while ertapenem showed a potential resistance of 13% (all P. aeruginosa strains). However, the combination of these drugs with gentamicin would have been increased the efficacy of the treatment to 99 and 100%, respectively. Resistance to piperacillin-tazobactam was 3%, while no strain was resistant to meropenem. Our data suggest that monotherapy with ampicillin-sulbactam or ertapenem for community-acquired secondary peritonitis would present a non-negligible rate of failure, but the addition of gentamycin to these drugs could reset to zero this risk. On the contrary, monotherapy with piperacillin-tazobactam or meropenem is highly effective. PMID:23906074

Castagnola, Elio; Bandettini, Roberto; Ginocchio, Francesca; Perotti, Maddalena; Masa, Daniela La; Ciucci, Antonella; Loy, Anna; Caviglia, Ilaria; Haupt, Riccardo; Guida, Edoardo; Pini Prato, Alessio; Mattioli, Girolamo; Buffa, Piero

2013-08-01

176

Dry matter and nutritional losses during aerobic deterioration of corn and sorghum silages as influenced by different lactic acid bacteria inocula.  

PubMed

The economic damage that results from aerobic deterioration of silage is a significant problem for farm profitability and feed quality. This paper quantifies the dry matter (DM) and nutritional losses that occur during the exposure of corn and sorghum silages to air over 14 d and assesses the possibility of enhancing the aerobic stability of silages through inoculation with lactic acid bacteria (LAB). The trial was carried out in Northern Italy on corn (50% milk line) and grain sorghum (early dough stage) silages. The crops were ensiled in 30-L jars, without a LAB inoculant (C), with a Lactobacillus plantarum inoculum (LP), and with a Lactobacillus buchneri inoculum (LB; theoretical rate of 1 × 10(6) cfu/g of fresh forage). The pre-ensiled material, the silage at silo opening, and the aerobically exposed silage were analyzed for DM content, fermentative profiles, yeast and mold count, starch, crude protein, ash, fiber components, 24-h and 48-h DM digestibility and neutral detergent fiber (NDF) degradability. The yield and nutrient analysis data of the corn and sorghum silages were used as input for Milk2006 to estimate the total digestible nutrients, net energy of lactation, and milk production per Mg of DM. The DM fermentation and respiration losses were also calculated. The inocula influenced the in vitro NDF digestibility at 24h, the net energy for lactation (NE(L)), and the predicted milk yield per megagram of DM, whereas the length of time of air exposure influenced DM digestibility at 24 and 48 h, the NE(L), and the predicted milk yield per megagram of DM in the corn silages. The inocula only influenced the milk yield per megagram of DM and the air exposure affected the DM digestibility at 24h, the NE(L), and the milk yield per megagram of DM in the sorghum silages. The milk yield, after 14 d of air exposure, decreased to 1,442, 1,418, and 1,277 kg/Mg of DM for C, LB, and LP corn silages, respectively, compared with an average value of 1,568 kg of silage at opening. In the sorghum silages, the milk yield, after 14 d of air exposure, decreased to 1,226, 1,278, and 1,250 kg/Mg of DM for C, LB, and LP, respectively. When the estimated milk yield per megagram of harvested DM of corn and sorghum silage were related to mold count, it was shown that the loss of potential milk production occurred when the mold count exceeded 4 log cfu/g of silage, and it was almost halved when the mold count reached values greater than 8 log cfu/g of silage. Inoculation with L. buchneri, at a rate of 1 × 10(6) cfu/g of fresh forage, enhanced the stability of the silage after exposure to air, and, consequently, contributed to maintaining the nutritional value of the harvested forage over time, for air exposure up to 7 d. PMID:21338806

Tabacco, E; Righi, F; Quarantelli, A; Borreani, G

2011-03-01

177

The Quantitative Swab Culture and Smear: A Quick, Simple Method for Determining the Number of Viable Aerobic Bacteria on Open Wounds.  

National Technical Information Service (NTIS)

The quantitative swab culture is a reliable method for quantifying the number of viable bacteria colonizing open wounds. For open wounds in burn patients, the swab bacterial count is linearly related to biopsy quantification of viable bacteria in the unde...

N. S. Levine R. B. Lindberg A. D. Mason B. A. Pruitt

1975-01-01

178

Phylogenetic Analysis of Bacterial Communities in Mesophilic and Thermophilic Bioreactors Treating Pharmaceutical Wastewater  

Microsoft Academic Search

The phylogenetic diversity of the bacterial communities supported by a seven-stage, full-scale biological wastewater treatment plant was studied. These reactors were operated at both mesophilic (28 to 32°C) and thermophilic (50 to 58°C) temperatures. Community fingerprint analysis by denaturing gradient gel electro- phoresis (DGGE) of the PCR-amplified V3 region of the 16S rRNA gene from the domain Bacteria revealed that

TIMOTHY M. LAPARA; CINDY H. NAKATSU; LISA PANTEA; JAMES E. ALLEMAN

2000-01-01

179

Aerobic granulation in a sequencing batch reactor  

Microsoft Academic Search

In a sequencing batch reactor (SBR) granules of aerobic heterotrophic microorganisms were cultured. The effect of different operational conditions on the formation of these aerobic granules were studied. The time allowed for settling was the main parameter to select for growth of bacteria in well settling granules. Both a short HRT and a relative high shear were found favorable for

J. J Beun; A Hendriks; M. C. M van Loosdrecht; E Morgenroth; P. A Wilderer; J. J Heijnen

1999-01-01

180

Searching for Mesophilic Thermotogales Bacteria: "Mesotogas" in the Wild? †  

PubMed Central

All cultivated Thermotogales are thermophiles or hyperthermophiles. However, optimized 16S rRNA primers successfully amplified Thermotogales sequences from temperate hydrocarbon-impacted sites, mesothermic oil reservoirs, and enrichment cultures incubated at <46°C. We conclude that distinct Thermotogales lineages commonly inhabit low-temperature environments but may be underreported, likely due to “universal” 16S rRNA gene primer bias.

Nesb?, Camilla L.; Kumaraswamy, Rajkumari; Dlutek, Marlena; Doolittle, W. Ford; Foght, Julia

2010-01-01

181

Lab scale experiments using a submerged MBR under thermophilic aerobic conditions for the treatment of paper mill deinking wastewater.  

PubMed

This paper describes the results of laboratory experiments using a thermophilic aerobic MBR (TMBR) at 50 °C. An innovative use of submerged flat-sheet MBR modules to treat circuit wastewater from the paper industry was studied. Two experiments were conducted with a flux of 8-13 L/m(2)/h without chemical membrane cleaning. COD and BOD(5) elimination rates were 83% and 99%, respectively. Calcium was reduced from 110 to 180 mg/L in the inflow to 35-60 mg/L in the permeate. However, only negligible membrane scaling occurred. The observed sludge yield was very low and amounted to 0.07-0.29 g MLSS/g COD(eliminated). Consequently, the nutrient supply of ammonia and phosphate can be lower compared to a mesophilic process. Molecular-biological FISH analysis revealed a likewise high diversity of microorganisms in the TMBR compared to the mesophilic sludge used for start-up. Furthermore, ammonia-oxidising bacteria were detected at thermophilic operation. PMID:22595101

Simstich, Benjamin; Beimfohr, Claudia; Horn, Harald

2012-04-20

182

Aerobic Gram-Positive and Gram-Negative Bacteria Exhibit Differential Sensitivity to and Transformation of 2,4,6Trinitrotoluene (TNT)  

Microsoft Academic Search

.   A systematic evaluation of the ability of different bacterial genera to transform 2,4,6-trinitrotoluene (TNT), and grow in\\u000a its presence, was conducted. Aerobic Gram-negative organisms degraded TNT and evidenced net consumption of reduced metabolites\\u000a when cultured in molasses medium. Some Gram-negative isolates transformed all the initial TNT to undetectable metabolites,\\u000a with no adsorption of TNT or metabolites to cells. Growth

Mark E. Fuller

1997-01-01

183

Comparative in vitro activity of ceftaroline, ceftaroline-avibactam, and other antimicrobial agents against aerobic and anaerobic bacteria cultured from infected diabetic foot wounds.  

PubMed

Foot infections are the most common infectious complication of diabetes. Moderate to severe diabetic foot infections (DFI) are typically polymicrobial with both aerobic and anaerobic organisms. The role of MRSA in these wounds has become an increasing concern. To determine if the addition of avibactam, a novel non-beta-lactam beta-lactamase inhibitor, to ceftaroline would be more active than ceftaroline alone, we tested 316 aerobic pathogens and 154 anaerobic recovered from patients with moderate to severe DFI, and compared ceftaroline with and without avibactam to other agents. Testing on aerobes was done by broth microdilution and by agar dilution for anaerobes, according to CLSI M11-A8, and M7-A8 standards. Ceftaroline-avibactam MIC90 for all Staphylococcus spp. including MRSA was 0.5 ?g/mL, and for enterococci was 1 ?g/mL. The MIC90s for enteric Gram-negative rods was 0.125 ?g/mL. The addition of avibactam to ceftaroline reduced the ceftaroline MICs for 2 strains of resistant Enterobacter spp. and for 1 strain of Morganella. Against anaerobic Gram-positive cocci ceftaroline-avibactam had an MIC90 0.125 ?g/mL and for clostridia 1 ?g/mL. Avibactam improved ceftaroline's MIC90s for Bacteroides fragilis from >32 to 2 ?g/mL and for Prevotella spp. from >32 to 1 ?g/mL. Ceftaroline alone demonstrates excellent in vitro activity against most of the aerobes found in moderate to severe DFI. The addition of avibactam provides an increased spectrum of activity including the beta-lactamase producing Prevotella, Bacteroides fragilis and ceftaroline resistant gram-negative enteric organisms. PMID:23623385

Goldstein, Ellie J C; Citron, Diane M; Merriam, C Vreni; Tyrrell, Kerin L

2013-04-24

184

Evaluation of the Use of PCR and Reverse Transcriptase PCR for Detection of Pathogenic Bacteria in Biosolids from Anaerobic Digestors and Aerobic Composters  

Microsoft Academic Search

A PCR-based method and a reverse transcriptase PCR (RT-PCR)-based method were developed for the detection of pathogenic bacteria in organic waste, using Salmonella spp., Listeria monocytogenes, Yersinia enterocolitica, and Staphylococcus aureus as model organisms. In seeded organic waste samples, detection limits of less than 10 cells per g of organic waste were achieved after one-step enrichment of bacteria, isolation, and

Carola Burtscher; Stefan Wuertz

2003-01-01

185

Biodegradation of agricultural herbicides in sequencing batch reactors under aerobic or anaerobic conditions  

Microsoft Academic Search

This study investigated the biodegradability of the herbicides isoproturon and 2,4-dichlorophenoxyacetic acid (2,4-D) in sequencing batch reactors (SBRs). Two laboratory-scale (2L liquid volume) SBRs were employed: one reactor performing under aerobic and the other under anaerobic conditions. The aerobic SBR was operated at an ambient temperature (22±2°C), while the anaerobic SBR was run in the lower mesophilic range (30±2°C). Each

E. Celis; P. Elefsiniotis; N. Singhal

2008-01-01

186

Comparative in vitro activities of trovafloxacin (CP-99,219) against 221 aerobic and 217 anaerobic bacteria isolated from patients with intra-abdominal infections.  

PubMed Central

Four hundred thirty-eight bacteria cultured from specimens of patients with serious intra-abdominal infections were tested by agar dilution against trovafloxacin and other quinolones and antimicrobial agents. Trovafloxacin inhibited 435 strains (99.3%) at < or =2 microg/ml. All the quinolones had similar activities against Enterobacteriaceae and Pseudomonas sp., but trovafloxacin showed superior activities against streptococci, enterococci, and anaerobic organisms. Because of its excellent in vitro activities against diverse bacteria, trovafloxacin has potential use as a single agent for polymicrobial infections.

Citron, D M; Appleman, M D

1997-01-01

187

Aerobic moving bed biofilm reactor treating thermomechanical pulping whitewater under thermophilic conditions  

Microsoft Academic Search

The continuously operated laboratory scale Kaldnes moving bed biofilm reactor (MBBR) was used for thermophilic (55°C) aerobic treatment of TMP whitewater. In the MBBR, the biomass is grown on carrier elements that move along with the water in the reactor. Inoculation with mesophilic activated sludge gave 60–65% SCOD removal from the first day onwards. During the 107 days of experiment,

Sigrun J Jahren; Jukka A Rintala; Hallvard Ødegaard

2002-01-01

188

Exposure of water consumers to mesophilic actinomycetes.  

PubMed

In autumn 1978 an epidemic of respiratory disease resembling allergic alveolitis occurred in a small Finnish community. The disease was caused by repeated exposures to tap water aerosol. The raw water of the community and the sand filters of the purification system were heavily contaminated with mesophilic actinomycetes. Fourteen different strains of actinomycetes were isolated. Exposed persons with and without symptoms as well as unexposed control persons were tested for antibodies against five of these actinomycetes and against Enterobacter agglomerans. Both the exposed and the control persons had antibodies to actinomycetes but the exposed persons had antibodies against more actinomycete strains than the control persons. Precipitating antibodies against E. agglomerans were also found in control persons as well as in patients. There was a significant difference between the patients and the exposed healthy persons in bacterial agglutination tests with flagellar antigen of one E. agglomerans strain. However, the role of mesophilic actinomycetes and E. agglomerans in the aetiology of the disease could not be firmly established. PMID:6663066

Ojanen, T H; Katila, M L; Mäntyjärvi, R; Seppänen, H; Muittari, A; Kuusisto, P; Virtanen, P

1983-12-01

189

Microbial ecology of solid cellulosic materials during aerobic digestion and anaerobic fermentation  

Microsoft Academic Search

A process for anaerobic digestion of cotton willow dust, pressmud and baggase after a preliminary alkaline aerobic digestion had been developed. The microbial ecologies during the aerobic digestion and anaerobic fermentation of these substrates were investigated, with respect to the isolation, identification and characterization of aerobic microorganisms. The study produced information on the survival of aerobic and facultative bacteria, actinomycetes

Charlene P D'Souza; R. H Balasubramanya

1999-01-01

190

Effect of sand and shaking duration on the recovery of aerobic bacteria, coliforms, and Escherichia coli from prechill broiler whole carcass rinsates.  

Technology Transfer Automated Retrieval System (TEKTRAN)

An experiment was conducted to determine the effect of added sand and shaking duration on the recovery of bacteria from broiler carcasses using the whole carcass rinse (WCR) method. In each of 4 replications, 12 eviscerated broiler carcasses were obtained from a commercial processing plant prior to ...

191

Isolation and characterization of heterotrophic bacteria able to grow aerobically with quaternary ammonium alcohols as sole source of carbon and nitrogen  

Microsoft Academic Search

The quaternary ammonium alcohols (QAAs) 2,3-dihydroxypropyl-trimethyl-ammonium (TM), dimethyl-diethanol-ammonium (DM) and methyl-triethanol-ammonium (MM) are hydrolysis products of their parent esterquat surfactants, which are widely used as softeners in fabric care. We isolated several bacteria growing with QAAs as the sole source of carbon and nitrogen. The strains were compared with a previously isolated TM-degrading bacterium, which was identified as a representative

Andres Kaech; Nathalie Vallotton; Thomas Egli

2005-01-01

192

Removal of polychlorinated dioxins by semi-aerobic fed-batch composting with biostimulation of "Dehalococcoides".  

PubMed

A semi-aerobic, mesophilic, fed-batch composting (FBC) reactor loaded with household garbage was used to remove polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs). The reactor was packed with woodchips as the solid matrix and PCDD/F-contaminated soil or flyash and then operated at a waste-loading rate of 0.5 kg (wet wt) day(-1). All congeners of PCDD/Fs (initial concentration, 200-830 pmol g(-1) [dry wt]) were totally reduced during the over period of operation, with a half reduction time of 4 months. Direct cell counting and respiratory quinone profiling showed that the reactors at the fully acclimated stage harbored a high population density of bacteria (10(11) g(-1) [dry wt]) with members of the Actinobacteria predominating. Real-time quantitative PCR showed that the population of "Dehalococcoides" and its phylogenetic relatives of Chloroflexi as the possible dechlorinators varied between at the order of 10(7) to 10(8) g(-1) (dry wt). A "Dehalococcoides"-containing dechlorinating culture from the soil-treating reactor was successfully enriched with a model PCDD/F compound, fthalide. 16S rRNA gene-targeted PCR-denaturated gradient gel electrophoresis and clone library analyses showed that this culture comprised at least three major phylogenetic groups of bacteria, Acidaminobacter, "Dehalococcoides," and Rhizobium. These results suggest that the semi-aerobic FBC process is applicable for the bioremediation of PCDD/Fs and possibly other haloorganic compounds with the biostimulation of "Dehalococcoides" and its relatives as the potent dechlorinators. PMID:20159573

Narihiro, Takashi; Kaiya, Shinichi; Futamata, Hiroyuki; Hiraishi, Akira

2009-09-19

193

Combined anaerobic and aerobic digestion for increased solids reduction and nitrogen removal.  

PubMed

A unique sludge digestion system consisting of anaerobic digestion followed by aerobic digestion and then a recycle step where thickened sludge from the aerobic digester was recirculated back to the anaerobic unit was studied to determine the impact on volatile solids (VS) reduction and nitrogen removal. It was found that the combined anaerobic/aerobic/anaerobic (ANA/AER/ANA) system provided 70% VS reduction compared to 50% for conventional mesophilic anaerobic digestion with a 20 day SRT and 62% for combined anaerobic/aerobic (ANA/AER) digestion with a 15 day anaerobic and a 5 day aerobic SRT. Total Kjeldahl nitrogen (TKN) removal for the ANA/AER/ANA system was 70% for sludge wasted from the aerobic unit and 43.7% when wasted from the anaerobic unit. TKN removal was 64.5% for the ANA/AER system. PMID:20801476

Novak, John T; Banjade, Sarita; Murthy, Sudhir N

2010-08-17

194

Genotypic identification of some lactic acid bacteria by amplified fragment length polymorphism analysis and investigation of their potential usage as starter culture combinations in Beyaz cheese manufacture.  

PubMed

In this study, 2 different starter culture combinations were prepared for cheesemaking. Starter culture combinations were formed from 8 strains of lactic acid bacteria. They were identified as Lactococcus lactis ssp. lactis (2 strains), Lactobacillus plantarum (5 strains), and Lactobacillus paraplantarum (1 strain) by amplified fragment length polymorphism analysis. The effects of these combinations on the physicochemical and microbiological properties of Beyaz cheeses were investigated. These cheeses were compared with Beyaz cheeses that were produced with a commercial starter culture containing Lc. lactis ssp. lactis and Lc. lactis ssp. cremoris as control. All cheeses were ripened in brine at 4 degrees C for 90 d. Dry matter, fat in dry matter, titratable acidity, pH, salt in dry matter, total N, water-soluble N, and ripening index were determined. Sodium dodecyl sulfate-PAGE patterns of cheeses showed that alpha(S)-casein and beta-casein degraded slightly during the ripening period. Lactic acid bacteria, total mesophilic aerobic bacteria, yeast, molds, and coliforms were also counted. All analyses were repeated twice during d 7, 30, 60, and 90. The starter culture combinations were found to be significantly different from the control group in pH, salt content, and lactobacilli, lactococci, and total mesophilic aerobic bacteria counts, whereas the cheeses were similar in fat, dry matter content, and coliform, yeast, and mold counts. The sensory analysis of cheeses indicated that textural properties of control cheeses presented somewhat lower scores than those of the test groups. The panelists preferred the tastes of treatment cheeses, whereas cheeses with starter culture combinations and control cheeses had similar scores for appearance and flavor. These results indicated that both starter culture combinations are suitable for Beyaz cheese production. PMID:20059897

Karahan, A G; Ba?yi?it Kiliç, G; Kart, A; Sanlidere Alo?lu, H; Oner, Z; Aydemir, S; Erku?, O; Harsa, S

2010-01-01

195

Comparative proteome analysis of psychrophilic versus mesophilic bacterial species: Insights into the molecular basis of cold adaptation of proteins  

PubMed Central

Background Cold adapted or psychrophilic organisms grow at low temperatures, where most of other organisms cannot grow. This adaptation requires a vast array of sequence, structural and physiological adjustments. To understand the molecular basis of cold adaptation of proteins, we analyzed proteomes of psychrophilic and mesophilic bacterial species and compared the differences in amino acid composition and substitution patterns to investigate their likely association with growth temperatures. Results In psychrophilic bacteria, serine, aspartic acid, threonine and alanine are overrepresented in the coil regions of secondary structures, whilst glutamic acid and leucine are underrepresented in the helical regions. Compared to mesophiles, psychrophiles comprise a significantly higher proportion of amino acids that contribute to higher protein flexibility in the coil regions of proteins, such as those with tiny/small or neutral side chains. Amino acids with aliphatic, basic, aromatic and hydrophilic side chains are underrepresented in the helical regions of proteins of psychrophiles. The patterns of amino acid substitutions between the orthologous proteins of psychrophiles versus mesophiles are significantly different for several amino acids when compared to their substitutions in orthologous proteins of within the mesophiles or psychrophiles. Conclusion Current results provide quantitative substitution preferences (or avoidance) of amino acids that lead to the adaptation of proteins to cold temperatures. These finding would help future efforts in selecting mutations for rational design of proteins with enhanced psychrophilic properties.

Metpally, Raghu Prasad Rao; Reddy, Boojala Vijay B

2009-01-01

196

Enumeration of Free-Living Aerobic N2-Fixing H2-Oxidizing Bacteria by Using a Heterotrophic Semisolid Medium and Most-Probable-Number Technique  

PubMed Central

A heterotrophic semisolid medium was used with two sensitive assay methods, C2H2 reduction and O2-dependent tritium uptake, to determine nitrogenase and hydrogenase activities, respectively. Organisms known to be positive for both activities showed hydrogenase activity in both the presence and absence of 1% C2H2, and thus, it was possible to test a single culture for both activities. Hydrogen uptake activity was detected for the first time in N2-fixing strains of Pseudomonas stutzeri. The method was then applied to the most-probable-number method of counting N2-fixing and H2-oxidizing bacteria in some natural systems. The numbers of H2-oxidizing diazotrophs were considerably higher in soil surrounding nodules of white beans than they were in the other systems tested. This observation is consistent with reports that the rhizosphere may be an important ecological niche for H2 transformation.

Barraquio, Wilfredo L.; Dumont, Ann; Knowles, Roger

1988-01-01

197

Influence of an aerobic fungus grown on solid culture on ruminal degradability and on a mixture culture of anaerobic cellulolytic bacteria.  

PubMed

In this work, the effect of a solid fungal culture of Aspergillus niger (An) grown on coffee pulp on the in situ ruminal degradability (RD) of corn stover was evaluated. In addition, the effect of its extracts on the in vitro dry matter disappearance (IVDMD) and on a mixed culture of anaerobic cellulolytic bacteria (MCACB) was also investigated. The solid ferment was a crude culture of An, grown on coffee pulp. Regarding in situ RD, a significant difference (p < 0.05) was found between treatment with 200 g/day of the solid culture and control (no solid culture added) on dry matter, crude protein and neutral detergent fibre on RD. All the water extracts (pH 4, 7 and 10) enhanced IVDMD and stimulated the cellulolytic activity on a MCACB. Ultrafiltration results showed that active compounds with a molecular weight lower than 30 kDa were responsible for the effect on MCACB. Such results suggest that the effects of the solid An culture in RD are related to the presence of water soluble compounds having a molecular weight lower than 30 kDa. PMID:19663984

Hernández-Díaz, R; Pimentel-González, D J; Figueira, A C; Viniegra-González, G; Campos-Montiel, R G

2009-08-03

198

Aerobic and Anaerobic Microbiology of Wound Infection following Spinal Fusion in Children  

Microsoft Academic Search

Objective: To study the aerobic and anaerobic microbiology of wound infections following spinal fusion in children. Methods: Retrospective review of clinical and microbiological records. Results: Aspirates of pus from 18 infection sites showed bacterial growth. Anaerobic bacteria only were recovered in 3 (17%) specimens, aerobic bacteria only in 3 (17%) and mixed aerobic and anaerobic bacteria in 12 (67%). Forty-two

Itzhak Brook; Edith H. Frazier

2000-01-01

199

Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions  

SciTech Connect

This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments.

Coyne, P.; Smith, G. [New Mexico State Univ., Las Cruces, NM (United States)

1995-08-15

200

Sequencing mesophilic and thermophilic anaerobic digesters. Final report  

SciTech Connect

This project employed two laboratory bench scale, complete-mix anaerobic sludge digesters arranged in a series configuration. The first digester was operated at 35/sup 0/C (mesophilic) and the second at 50/sup 0/C (thermophilic). A portion of the thermophilic sludge was recycled through an aeration basin. As a comparison to the mesophilic-thermophilic sequencing, a mesophilic-mesophilic digester sequence, without sludge recycle to the aeration basin, was operated in parallel to the test units and loaded at an equivalent rate. Conclusions of this study are as follows: in establishing a thermophilic anaerobic digester, a slow-start procedure, in which the temperature is increased at a rate of 0.6/sup 0/C per day with loading, appears to produce a more stable thermophilic digester in a shorter period of time than a quick-start procedure, in which the temperature is increased rapidly with no loading. Even after a year, the slow-start thermophilic digester proved to be unstable once sequencing began. A greater volatile solids, COD, BOD, and grease reduction with a higher gas production was achieved using a mesophilic-mesophilic sequence, probably, in part, due to the instability (volatile acids in the effluent) of the thermophilic digester in the mesophilic-thermophilic sequence. A greater total kjeldahl N (TKN) and total coliform destruction was achieved in the thermophilic digester, however, poor dewatering characteristics, as indicated by the capillary suction time (CST), and an obnoxious odor were also evident. Other than an increase in effluent suspended solids, the recycle of thermophilic sludge to an aeration basin produced no discernable effect. 9 figs., 3 tabs.

Not Available

1982-12-01

201

Teaching Aerobic Fitness Concepts.  

ERIC Educational Resources Information Center

|Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

Sander, Allan N.; Ratliffe, Tom

2002-01-01

202

Studies of Methanogenic Bacteria in Sludge.  

National Technical Information Service (NTIS)

Methanogenic bacteria were isolated from mesophilic anaerobic digesters. The isolates were able to utilize H2 and CO2 acetate, formate and methanol, but were not able to metabolize propionate and butyrate. It was shown the propionate and butyrate are not ...

P. H. Smith

1980-01-01

203

Megaplasmids of Aerobic Hydrogenotrophic and Carboxidotrophic Bacteria  

Microsoft Academic Search

\\u000a The hydrogen-oxidizing bacterium Ralstonia eutropha H16 and the carbon monoxide-oxidizing bacterium Oligotropha carboxidovorans OM5 carry key genetic determinants for their respective forms of lithoautotrophic metabolism on megaplasmids. In R. eutropha H16 genetic information for the H2-oxidizing system and for CO2 fixation via the Calvin—Benson—Bassham cycle is located on the 452-kb megaplasmid pHG1. In addition, pHG1 harbors clusters\\u000a of genes for

Edward Schwartz

204

Influence of Phenol-Polluted Air on the Structure and Microbial Populations of Aerobic Granuels  

Microsoft Academic Search

The phenol-polluted air was degraded by aerobic granules at a high phenol loading rate and the characteristics of aerobic granules were investigated. The morphology and structure of aerobic granule changed greatly when they degraded phenol-polluted air. The white bamboo-shaped filamentous bacteria grown were completely covered on the surface of aerobic granules at the phenol loading rate of 1.5 kg m-3

Ping Zeng; Liguo Zhao; Jijun Du; Yong-hui Song

2010-01-01

205

Aerobic and Anaerobic Microbiology of Surgical-Site Infection Following Spinal Fusion  

Microsoft Academic Search

The aerobic and anaerobic microbiology of surgical-site infections (SSI) following spinal fusion was retro- spectively studied. This was done by reviewing the clinical and microbiological records at the Naval Hospital in Bethesda, Md., from 1980 to 1992. Aspirates of pus from 25 infection sites showed bacterial growth. Aerobic bacteria only were recovered from 9 (36%) specimens, anaerobic bacteria only were

ITZHAK BROOK; EDITH H. FRAZIER

1999-01-01

206

Thiocyanate decomposition under aerobic and oxygen-free conditions by the aboriginal bacterial community isolated from the waste water of a metallurgical works  

Microsoft Academic Search

A mesophilic alkalitolerant aboriginal bacterial community capable of autotrophic thiocyanate decomposition under aerobic\\u000a and oxygen-free conditions was isolated from reused water of a metallurgical works. The growth of the aboriginal bacterial\\u000a community was optimal at pH 9.0. Ammonium and sulfate were the end products of thiocyanate decomposition under both aerobic\\u000a and oxygen-free conditions. Under oxygen-free conditions, thiocyanate decomposition occurred in

N. V. Grigor’eva; Yu. V. Smirnova; L. E. Dulov

2009-01-01

207

Comparison of mesophilic and thermophilic upflow anaerobic sludge blanket reactors treating instant coffee production wastewater  

Microsoft Academic Search

Stable anaerobic digestion of settled instant coffee wastewater was achieved for over 100 days in mesophilic (35°C) and termophilic (55°C) UASB reactors. Thermophilic upflow anaerobic sludge blankets (UASBs) were seeded with mesophilic granules and converted to thermophilic operation by raising the temperature to 55°C in one step. Successful thermophilic operation was achieved within 28 days. Both mesophilic and thermophilic UASBs

Richard M. Dinsdale; Freda R. Hawkes; Dennis L. Hawkes

1997-01-01

208

Mesophilic crenarchaeota: proposal for a third archaeal phylum, the Thaumarchaeota  

Microsoft Academic Search

The archaeal domain is currently divided into two major phyla, the Euryarchaeota and Crenarchaeota. During the past few years, diverse groups of uncultivated mesophilic archaea have been discovered and affiliated with the Crenarchaeota. It was recently recognized that these archaea have a major role in geochemical cycles. Based on the first genome sequence of a crenarchaeote, Cenarchaeum symbiosum, we show

Bastien Boussau; Simonetta Gribaldo; Patrick Forterre; Céline Brochier-Armanet

2008-01-01

209

Ryegrass straw component decomposition during mesophilic and thermophilic incubations  

Microsoft Academic Search

The decomposition of perennial ryegrass straw was examined under mesophilic and thermophilic temperatures. Thermophilic conditions were used to define the composting process. The change in lipids, sugars, soluble polysaccharides, cellulose, and lignin was determined during a 45-day incubation. C, H, O, and N steadily decreased in both temperature treatments. The lignin content, as measured by the Klason or 72% H2SO4

W. R. Horwath; Lloyd F. Elliott

1996-01-01

210

Diversity, Localization, and Physiological Properties of Filamentous Microbes Belonging to Chloroflexi Subphylum I in Mesophilic and Thermophilic Methanogenic Sludge Granules  

PubMed Central

We previously reported that the thermophilic filamentous anaerobe Anaerolinea thermophila, which is the first cultured representative of subphylum I of the bacterial phylum Chloroflexi, not only was one of the predominant constituents of thermophilic sludge granules but also was a causative agent of filamentous sludge bulking in a thermophilic (55°C) upflow anaerobic sludge blanket (UASB) reactor in which high-strength organic wastewater was treated (Y. Sekiguchi, H. Takahashi, Y. Kamagata, A. Ohashi, and H. Harada, Appl. Environ. Microbiol. 67:5740-5749, 2001). To further elucidate the ecology and function of Anaerolinea-type filamentous microbes in UASB sludge granules, we surveyed the diversity, distribution, and physiological properties of Chloroflexi subphylum I microbes residing in UASB granules. Five different types of mesophilic and thermophilic UASB sludge were used to analyze the Chloroflexi subphylum I populations. 16S rRNA gene cloning-based analyses using a 16S rRNA gene-targeted Chloroflexi-specific PCR primer set revealed that all clonal sequences were affiliated with the Chloroflexi subphylum I group and that a number of different phylotypes were present in each clone library, suggesting the ubiquity and vast genetic diversity of these populations in UASB sludge granules. Subsequent fluorescence in situ hybridization (FISH) of the three different types of mesophilic sludge granules using a Chloroflexi-specific probe suggested that all probe-reactive cells had a filamentous morphology and were widely distributed within the sludge granules. The FISH observations also indicated that the Chloroflexi subphylum I bacteria were not always the predominant populations within mesophilic sludge granules, in contrast to thermophilic sludge granules. We isolated two mesophilic strains and one thermophilic strain belonging to the Chloroflexi subphylum I group. The physiological properties of these isolates suggested that these populations may contribute to the degradation of carbohydrates and other cellular components, such as amino acids, in the bioreactors.

Yamada, Takeshi; Sekiguchi, Yuji; Imachi, Hiroyuki; Kamagata, Yoichi; Ohashi, Akiyoshi; Harada, Hideki

2005-01-01

211

Modified-atmosphere packaging of hen table eggs: effects on pathogen and spoilage bacteria.  

PubMed

As part of a more comprehensive research activity on the use of modified-atmosphere packaging for the improvement of quality and functional properties of table eggs, the effects of air, 100% CO(2), and 100% O(2) packaging were also evaluated on the survival of experimentally inoculated pathogen bacteria (Salmonella Enteritidis, Escherichia coli, and Listeria monocytogenes) as well as on spoilage bacteria (total aerobic mesophilic bacteria) on table eggs during 30 d of storage at 4, 25, and 37°C by colony count method. In general, temperatures played a major role, rather than gasses, in influencing the bacterial survival. In particular, the lowest microbial loads were registered at 4°C on E. coli and spoilage bacteria, whereas 37°C was the best storage temperature to avoid the psychrotropic microorganism L. monocytogenes development regardless of the gas used. One hundred percent CO(2) packaging, in association with a low storage temperature (4°C), had a significant positive effect in reducing Salmonella loads. On eggs inoculated with L. monocytogenes and stored at 4°C as well as on eggs containing only spoilage bacteria and stored at 25°C, 100% CO(2) resulted the best gas in comparison with air and O(2). One hundred percent CO(2) packaging showed no negative effect on pathogen survival compared with air. Although further improvements are required to control RH within packaging to limit bacteria growth/survival, in view of the positive effects of CO(2) packaging on quality traits of table eggs, 100% CO(2) packaging might represent a promising innovative technique for the maintenance of egg characteristics during transport, retail, and domestic storage. PMID:23155038

Pasquali, F; Manfreda, G; Olivi, P; Rocculi, P; Sirri, F; Meluzzi, A

2012-12-01

212

Aerobic Dance and Cheerleading  

Microsoft Academic Search

\\u000a For over 30 years, aerobic dance has been one of the most popular forms of cardiovascular exercise in America. Step\\/bench\\u000a aerobics has evolved from a high-impact aerobic “exercise dance” form with a high degree of lower extremity injuries to a\\u000a safer form of low-impact dance. The reduction of impact shock to the lower extremities has aided in the reduction of

Jeffrey A. Ross

213

Correlation of 16S Ribosomal DNA Signature Sequences with Temperature-Dependent Growth Rates of Mesophilic and Psychrotolerant Strains of the Bacillus cereus Group  

Microsoft Academic Search

Sequences of the 16S ribosomal DNA (rDNA) from psychrotolerant and mesophilic strains of the Bacillus cereus group revealed signatures which were specific for these two thermal groups of bacteria. Further analysis of the genomic DNA from a wide range of food and soil isolates showed that B. cereus group strains have between 6 and 10 copies of 16S rDNA. Moreover,

BIRGIT M. PRU; KEVIN P. FRANCIS; FELIX VON STETTEN; SIEGFRIED SCHERER

1999-01-01

214

The role of atypical bacteria in chronic rhinosinusitis  

Microsoft Academic Search

Problem: Conflicting studies exist on the microbiology of chronic rhinosinusitis (CRS), but none identify atypical bacteria, owing to these bacteria’s fastidious nature. Atypical bacteria are common causes of pneumonia. However, their role in upper respiratory disease is less clear. Recently the polymerase chain reaction has been valuable in detecting aerobic and anaerobic bacteria, fungi, and viruses implicated in chronic rhinosinusitis.

Raymond E. Lee; Sarita Kaza; Gregory V. Plano; Roy R. Casiano

2004-01-01

215

A survey of bacteria and fungi occurring during composting and self-heating processes  

Microsoft Academic Search

Composting is a controlled self-heating, aerobic solid phase biodegradative process of organic materials. The process comprises mesophilic and thermophilic phases involving numerous microorganisms. In several successive steps, microbial communities degrade organic substrates into more stable, humified forms and inorganic products, gener- ating heat as a metabolic waste product. Due to the complexity of substrates and intermedi- ate products, microbial diversity

J. RYCKEBOER; J. MERGAERT; K. VAES; S. KLAMMER; D. DE CLERCQ; J. COOSEMANS; H. INSAM; J. SWINGS

2003-01-01

216

[Sensitivity of urogenital aerobic microflora to antibiotics].  

PubMed

The following aerobic opportunistic bacteria have been isolated in women with different inflammatory processes of the reproductive system: staphylococci--62%, enterobacteria--30%, streptococci--11%, pseudomonads--7%. Gram-positive cocci (staphylococci and streptococci, except for Streptococcus faecium) manifested the highest sensitivity to amoxycillin/clavulanic acid. Clinical isolates of enterobacteria were characterized by high percentage of strains sensitive to cyprofloxacine and cephalosporines of the third generation. The highest number of sensitive strains was registered in fluoroquinolon for Pseudomonas aeruginosa. PMID:11785424

Sirokvasha, E A; Krysenko, A V; Skliar, T V; Vinnikov, A I

217

The aerobic decomposition of choline by microorganisms  

Microsoft Academic Search

1.The ability to decompose choline is widespread among aerobic microorganisms since representatives of the genera Agrobacterium, Arthrobacter, Micrococcus, Pseudomonas, Rhizobium, and Streptomyces and a large number of coryneform bacteria were found to grow with choline as the sole C- and N-source.2.Almost all the coryneforms isolated from soil and dairy waste activated sludge displayed this ability in contrast to those isolated

G. J. J. Kortstee

1970-01-01

218

Structural basis for altering the stability of homologous RNAs from a mesophilic and a thermophilic bacterium  

PubMed Central

Tertiary RNA structures from thermophilic bacteria generally are more stable than their mesophilic homologs. To understand the structural basis of the increase in stability, we investigated equilibrium folding of the specificity domain (S-domain) of RNase P RNA from a mesophilic (Escherichia coli) and a thermophilic (Thermus thermophilus) bacterium. Equilibrium folding of both S-domains is described by a minimal, three-state folding scheme, U-to-I-to-N. In the I-to-N transition of the thermophilic S-domain, more structure forms and protections are stronger against T1 nuclease and hydroxyl radical reactions. Phylogenetic comparison in the context of the native structure reveals that among 39 nucleotide differences between these S-domains, 12 likely contribute to higher stability. These residues participate in extensive networks of hydrogen bonding, stacking, and metal ion coordination throughout the molecule. The thermophilic S-domain achieves higher stability by mutating strategic base pairs to G-C, decreasing surface accessibility of the native state, and increasing the amount of structure formation in the native folding transition. An E. coli S-domain mutant containing these 12 nt has the same stability and folding cooperativity as the T. thermophilus S-domain. E. coli S-domain mutants containing a subset of 4 or 6 nt have the same stability as the T. thermophilus S-domain but the same folding cooperativity as the E. coli S-domain. These results show that increasing stability can be accomplished by mutations within a local structure, but increasing folding cooperativity needs concerted changes among multiple structural units.

BAIRD, NATHAN J.; SRIVIDYA, NARAYANAN; KRASILNIKOV, ANDREY S.; MONDRAGON, ALFONSO; SOSNICK, TOBIN R.; PAN, TAO

2006-01-01

219

Treatment of organic synthesis wastewater using anaerobic packed bed and aerobic suspended growth bioreactors.  

PubMed

The performance of an anaerobic mesophilic packed bed reactor, with a mixture of GAC and tezontle, followed by an aerobic suspended growth system was studied for the treatment of organic chemical wastewater with a high COD concentration (22-29 g/L). The testing of the anaerobic-aerobic system was conducted in an experimental set-up for almost 2.5 years. Different operational conditions were evaluated. The anaerobic reactor showed performance stability and COD removals higher than 80% were obtained with loads up to 16.6 kg x m(-3) x d(-1). The acclimation of the aerobic biomass to the substrate in the anaerobic effluent was very quick and COD removals higher than 94% were obtained even at high organic loads. The combined anaerobic-aerobic system allowed total COD removals higher than 99.5% and the accomplishment of the discharge requirements of 200 mgCOD/L when the anaerobic reactor was operated with loads of 8-11 kg x m(-3)x d(-1) and the aerobic reactor with 0.33 kg x kg(-1) x d(-1), being the total HRT of 4.4. The average TKN removal in the anaerobic-aerobic system was 97%, the average for the anaerobic reactor being 52% and that one for the aerobic system being 94%. PMID:17506443

Mijaylova-Nacheva, P; Ramírez-Camperos, E; Cuevas-Velasco, S

2007-01-01

220

Aerobic Production of Ethanol.  

National Technical Information Service (NTIS)

A computer-controlled continuous culture of yeast converted glucose to ethanol at excellent rates on a per-cell basis. This highly unconventional aerobic bioprocess makes use of oxidoreductive metabolism induced by concentrations of glucose that overload ...

L. S. Clesceri H. R. Bungay

1990-01-01

221

Bryobacter aggregatus gen. nov., sp. nov., a peat-inhabiting, aerobic chemo-organotroph from subdivision 3 of the Acidobacteria.  

PubMed

Bryobacter aggregatus gen. nov., sp. nov. is proposed to accommodate three strains of slowly growing, chemo-organotrophic bacteria isolated from acidic Sphagnum peat bogs. These bacteria were strictly aerobic, Gram-negative, colourless, non-motile coccoids or short rods that multiplied by normal cell division and formed irregularly shaped cell aggregates. Strains MPL3(T), MPL1011 and MOB76 were acidotolerant, mesophilic organisms capable of growth at pH 4.5-7.2 and between 4 and 33 degrees C (optimum growth at pH 5.5-6.5 and 22-28 degrees C). The preferred growth substrates were sugars, some heteropolysaccharides and galacturonic and glucuronic acids, which are released during decomposition of Sphagnum moss. The major fatty acids were iso-C(15 : 0), C(16 : 0) and summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c); the major quinones were MK-9 and MK-10. The DNA G+C content was 55.5-56.5 mol%. Strains MPL3(T), MPL1011 and MOB76 possessed nearly identical 16S rRNA gene sequences and belonged to the phylum Acidobacteria. They represent the first taxonomically characterized members of acidobacterial subdivision 3 and display only 81.7-86.7 % 16S rRNA gene sequence similarity to other members of the Acidobacteria with validly published names. Therefore, strains MPL3(T), MPL1011 and MOB76 are classified as representatives of a novel species in a new genus, for which the name Bryobacter aggregatus gen. nov., sp. nov. is proposed; strain MPL3(T) (=ATCC BAA-1390(T) =DSM 18758(T)) is the type strain of Bryobacter aggregatus. PMID:19651730

Kulichevskaya, Irina S; Suzina, Natalia E; Liesack, Werner; Dedysh, Svetlana N

2009-08-03

222

Microbiological quality of ready-to-eat salads: An underestimated vehicle of bacteria and clinically relevant antibiotic resistance genes.  

PubMed

The increase demand for fresh vegetables is causing an expansion of the market for minimally processed vegetables along with new recognized food safety problems. To gain further insight on this topic we analyzed the microbiological quality of Portuguese ready-to-eat salads (RTS) and their role in the spread of bacteria carrying acquired antibiotic resistance genes, food products scarcely considered in surveillance studies. A total of 50 RTS (7 brands; split or mixed leaves, carrot, corn) were collected in 5 national supermarket chains in Porto region (2010). They were tested for aerobic mesophilic counts, coliforms and Escherichia coli counts as well as for the presence of Salmonella and Listeria monocytogenes. Samples were also plated in different selective media with/without antibiotics before and after enrichment. The E. coli, other coliforms and Enterococcus recovered were characterized for antibiotic resistance profiles and clonality with phenotypic and genetic approaches. A high number of RTS presented poor microbiological quality (86%-aerobic mesophilic counts, 74%-coliforms, 4%-E. coli), despite the absence of screened pathogens. In addition, a high diversity of bacteria (species and clones) and antibiotic resistance backgrounds (phenotypes and genotypes) were observed, mostly with enrichment and antibiotic selective media. E. coli was detected in 13 samples (n=78; all types and 4 brands; phylogenetic groups A, B1 and D; none STEC) with resistance to tetracycline [72%; tet(A) and/or tet(B)], streptomycin (58%; aadA and/or strA-strB), sulfamethoxazole (50%; sul1 and/or sul2), trimethoprim (50%; dfrA1 or dfrA12), ampicillin (49%; blaTEM), nalidixic acid (36%), ciprofloxacin (5%) or chloramphenicol (3%; catA). E. coli clones, including the widespread group D/ST69, were detected in different samples from the same brand or different brands pointing out to a potential cross-contamination. Other clinically relevant resistance genes were detected in 2 Raoultella terrigena carrying a blaSHV-2 and 1 Citrobacter freundii isolate with a qnrB9 gene. Among Enterococcus (n=108; 35 samples; Enterococcus casseliflavus-40, Enterococcus faecalis-20, Enterococcus faecium-18, Enterococcus hirae-9, Enterococcus gallinarum-5, and Enterococcus spp.-16) resistance was detected for tetracyclines [6%; tet(M) and/or tet(L)], erythromycin [3%; erm(B)], nitrofurantoin (1%) or ciprofloxacin (1%). The present study places ready-to-eat salads within the spectrum of ecological niches that may be vehicles for antibiotic resistance bacteria/genes with clinical interest (e.g. E. coli-D-ST69; blaSHV-2) and these findings are worthy of attention as their spread to humans by ingestion cannot be dismissed. PMID:24036261

Campos, Joana; Mourão, Joana; Pestana, Nazaré; Peixe, Luísa; Novais, Carla; Antunes, Patrícia

2013-08-17

223

Isolation and Characterization of Polymeric Galloyl-Ester-Degrading Bacteria from a Tannery Discharge Place  

Microsoft Academic Search

The culturable bacteria colonizing the rhizosphere of plants growing in the area of discharge of a tannery effluent were characterized. Relative proportions of aerobic, denitrifying, and sulfate-reducing bacteria were determined in the rhizosphere of Typha latifolia, Canna indica, and Phragmites australis. Aerobic bacteria were observed to be the most abundant group in the rhizosphere, and plant type did not seem

A. R. Franco; C. S. C. Calheiros; C. C. Pacheco; P. De Marco; C. M. Manaia; P. M. L. Castro

2005-01-01

224

Electrostatic strengths of salt bridges in thermophilic and mesophilic glutamate dehydrogenase monomers  

Microsoft Academic Search

Here we seek to understand the higher frequency of occurrence of salt bridges in proteins from thermophiles as compared to their mesophile homologs. We focus on glutamate dehy- drogenase, owing to the availability of high resolu- tion thermophilic (from Pyrococcus furiosus) and mesophilic (from Clostridium symbiosum) protein structures, the large protein size and the large difference in melting temperatures. We

Sandeep Kumar; Buyong Ma; Chung-Jung Tsai; Ruth Nussinov

2000-01-01

225

Double Mutation in Photosystem II Reaction Centers and Elevated CO2 Grant Thermotolerance to Mesophilic Cyanobacterium  

Microsoft Academic Search

Photosynthetic biomass production rapidly declines in mesophilic cyanobacteria grown above their physiological temperatures largely due to the imbalance between degradation and repair of the D1 protein subunit of the heat susceptible Photosystem II reaction centers (PSIIRC). Here we show that simultaneous replacement of two conserved residues in the D1 protein of the mesophilic Synechocystis sp. PCC 6803, by the analogue

Jorge Dinamarca; Oksana Shlyk-Kerner; David Kaftan; Eran Goldberg; Alexander Dulebo; Manuel Gidekel; Ana Gutierrez; Avigdor Scherz

2011-01-01

226

Hydrogen production from food waste in anaerobic mesophilic and thermophilic acidogenesis  

Microsoft Academic Search

Hydrogen production from food waste by the mesophilic and thermophilic acidogenic culture acclimated with food waste at 5 days HRT for the effect of pH and volatile solid (VS) concentrations was evaluated. The biogas produced from the thermophilic acidogenic culture was free of methane at all tested pH and VS concentrations, but methane was detected from the mesophilic acidogenic culture

Hang-Sik Shin; Jong-Ho Youn; Sang-Hyoun Kim

2004-01-01

227

Functional organization of a single nif cluster in the mesophilic archaeon Methanosarcina mazei strain Gö1.  

PubMed

The mesophilic methanogenic archaeon Methanosarcina mazei strain Gö1 is able to utilize molecular nitrogen (N2) as its sole nitrogen source. We have identified and characterized a single nitrogen fixation (nif) gene cluster in M. mazei Gö1 with an approximate length of 9 kbp. Sequence analysis revealed seven genes with sequence similarities to nifH, nifI1, nifI2, nifD, nifK, nifE and nifN, similar to other diazotrophic methanogens and certain bacteria such as Clostridium acetobutylicum, with the two glnB-like genes (nifI1 and nifI2) located between nifH and nifD. Phylogenetic analysis of deduced amino acid sequences for the nitrogenase structural genes of M. mazei Gö1 showed that they are most closely related to Methanosarcina barkeri nif2 genes, and also closely resemble those for the corresponding nif products of the gram-positive bacterium C. acetobutylicum. Northern blot analysis and reverse transcription PCR analysis demonstrated that the M. mazei nif genes constitute an operon transcribed only under nitrogen starvation as a single 8 kb transcript. Sequence analysis revealed a palindromic sequence at the transcriptional start site in front of the M. mazei nifH gene, which may have a function in transcriptional regulation of the nif operon. PMID:15803652

Ehlers, Claudia; Veit, Katharina; Gottschalk, Gerhard; Schmitz, Ruth A

2002-09-01

228

Impact of microparticles on UV disinfection of indigenous aerobic spores  

Microsoft Academic Search

Numerous studies have shown that the efficacy of ultraviolet (UV) disinfection can be hindered by the presence of particles that can shield microorganisms. The main objective of this study was to determine to what extent natural particulate matter can shield indigenous spores of aerobic spore-forming bacteria (ASFB) from UV rays. The extent of the protective shielding was assessed by comparing

Eric Caron; Gabriel Chevrefils Jr.; Benoit Barbeau; Pierre Payment; Michèle Prévost

2007-01-01

229

Implementation of Aerobic Programs.  

ERIC Educational Resources Information Center

|This information is intended for health professionals interested in implementing aerobic exercise programs in public schools, institutions of higher learning, and business and industry workplaces. The papers are divided into three general sections. The introductory section presents a basis for adhering to a health fitness lifestyle, using…

American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD).

230

Managing for Improved Aerobic Stability  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aerobic deterioration or spoilage of silage is the result of aerobic microorganisms metabolizing components of the silage using oxygen. In the almost 40 years over which these silage conferences have been held, we have come to recognize the typical pattern of aerobic microbial development by which s...

231

Comparative conformational properties of thermophilic and mesophilic 6-phosphogluconate dehydrogenase.  

PubMed

The structural properties of 6-phosphogluconate dehydrogenase from the mesophilic bacterium E. coli and the thermophilic B. stearothermophilus are compared using circular dichroism and fluorescence emission spectroscopy. The enzymes appear to possess a similar structure which does not change on heating up to the respective temperature of stability of the enzyme. The thermostability of the two 6-phosphogluconate dehydrogenases as determined by activity measurements parallels that determined by CD with the melting profile method, indicating that the loss of biological activity in the enzymes is directly related to the unfolding of the protein molecule. The pattern of unfolding of the proteins by the action of 8 M urea suggests that a core of enhanced conformational stability exists in the B. stearothermophilus enzyme. PMID:780123

Veronese, F M; Grandi, C; Boccù, E; Fontana, A

1976-01-01

232

Control of ribosomal protein L1 synthesis in mesophilic and thermophilic archaea.  

PubMed Central

The mechanisms for the control of ribosomal protein synthesis have been characterized in detail in Eukarya and in Bacteria. In Archaea, only the regulation of the MvaL1 operon (encoding ribosomal proteins MvaL1, MvaL10, and MvaL12) of the mesophilic Methanococcus vannielii has been extensively investigated. As in Bacteria, regulation takes place at the level of translation. The regulator protein MvaL1 binds preferentially to its binding site on the 23S rRNA, and, when in excess, binds to the regulatory target site on its mRNA and thus inhibits translation of all three cistrons of the operon. The regulatory binding site on the mRNA, a structural mimic of the respective binding site on the 23S rRNA, is located within the structural gene about 30 nucleotides downstream of the ATG start codon. MvaL1 blocks a step before or at the formation of the first peptide bond of MvaL1. Here we demonstrate that a similar regulatory mechanism exists in the thermophilic M. thermolithotrophicus and M. jannaschii. The L1 gene is cotranscribed together with the L10 and L11 gene, in all genera of the Euryarchaeota branch of the Archaea studied so far. A potential regulatory L1 binding site located within the structural gene, as in Methanococcus, was found in Methanobacterium thermoautotrophicum and in Pyrococcus horikoshii. In contrast, in Archaeoglobus fulgidus a typical L1 binding site is located in the untranslated leader of the L1 gene as described for the halophilic Archaea. In Sulfolobus, a member of the Crenarchaeota, the L1 gene is part of a long transcript (encoding SecE, NusG, L11, L1, L10, L12). A previously suggested regulatory L1 target site located within the L11 structural gene could not be confirmed as an L1 binding site.

Kraft, A; Lutz, C; Lingenhel, A; Grobner, P; Piendl, W

1999-01-01

233

Experimental Evolution of a Facultative Thermophile from a Mesophilic Ancestor  

PubMed Central

Experimental evolution via continuous culture is a powerful approach to the alteration of complex phenotypes, such as optimal/maximal growth temperatures. The benefit of this approach is that phenotypic selection is tied to growth rate, allowing the production of optimized strains. Herein, we demonstrate the use of a recently described long-term culture apparatus called the Evolugator for the generation of a thermophilic descendant from a mesophilic ancestor (Escherichia coli MG1655). In addition, we used whole-genome sequencing of sequentially isolated strains throughout the thermal adaptation process to characterize the evolutionary history of the resultant genotype, identifying 31 genetic alterations that may contribute to thermotolerance, although some of these mutations may be adaptive for off-target environmental parameters, such as rich medium. We undertook preliminary phenotypic analysis of mutations identified in the glpF and fabA genes. Deletion of glpF in a mesophilic wild-type background conferred significantly improved growth rates in the 43-to-48°C temperature range and altered optimal growth temperature from 37°C to 43°C. In addition, transforming our evolved thermotolerant strain (EVG1064) with a wild-type allele of glpF reduced fitness at high temperatures. On the other hand, the mutation in fabA predictably increased the degree of saturation in membrane lipids, which is a known adaptation to elevated temperature. However, transforming EVG1064 with a wild-type fabA allele had only modest effects on fitness at intermediate temperatures. The Evolugator is fully automated and demonstrates the potential to accelerate the selection for complex traits by experimental evolution and significantly decrease development time for new industrial strains.

Blaby, Ian K.; Lyons, Benjamin J.; Wroclawska-Hughes, Ewa; Phillips, Grier C. F.; Pyle, Tyler P.; Chamberlin, Stephen G.; Benner, Steven A.; Lyons, Thomas J.

2012-01-01

234

[Evaluation of normal aerobic skin flora (author's transl)].  

PubMed

This work attempts the quantitative and qualitative evaluation of the bacterial population from two different areas: elbow and groin. Bacteria are recovered using the method of Williamson and Kligman modified by Fleurette and Transy. Aerobic flora is determined from bacterial counts on various media. Results show a density of 475 to 630 bacteria/cm2 for elbow, and 1.9 to 2.4 X 10(5) bacteria/cm2 for groin (geometric and arithmetic mean, respectively). Percentages of different species and types are calculated, and skin population is represented by a circular diagram. PMID:7458112

Crémieux, A; Cazac, J L

235

Experimental aerobic-anaerobic thoracic empyema in the guinea pig.  

PubMed

The clinical and pathological features of experimental aerobic-anaerobic thoracic empyema in the Duncan-Harley guinea pig are described. Thoracic empyema development and early death (less than 14 days after bacterial inoculation) were noted after various concentrations and species were inoculated into the pleural space with a piece of umbilical tape, which was used as a cofactor. The effect of concomitant hemothorax was also tested. Gram-negative infection was found to have a more virulent course than Gram-positive infection in the thoracic cavity. Moreover, these findings support the thesis that intrathoracic inoculation of anaerobic bacteria, even in combination with other anaerobic species, fails to produce clinical empyemas. However, anaerobic bacteria appear to enhance synergistically the virulence of sublethal and subempyema-forming concentrations of aerobic bacteria such as Staphylococcus aureus and Escherichia coli. PMID:3548615

Mavroudis, C; Ganzel, B L; Cox, S K; Polk, H C

1987-03-01

236

New Routes for Aerobic Biodegradation of Dimethylsulfoniopropionate  

PubMed Central

Dimethylsulfoniopropionate (DMSP), an osmolyte in marine plants, is biodegraded by cleavage of dimethyl sulfide (DMS) or by demethylation to 3-methiolpropionate (MMPA) and 3-mercaptopropionate (MPA). Sequential demethylation has been observed only with anoxic slurries of coastal sediments. Bacteria that grew aerobically on MMPA and DMSP were isolated from marine environments and phytoplankton cultures. Enrichments with DMSP selected for bacteria that generated DMS, whereas MMPA enrichments selected organisms that produced methanethiol (CH3SH) from either DMSP or MMPA. A bacterium isolated on MMPA grew on MMPA and DMSP, but rapid production of CH3SH from DMSP occurred only with DMSP-grown cells. Low levels of MPA accumulated during growth on MMPA, indicating demethylation as well as demethiolation of MMPA. The alternative routes for DMSP biodegradation via MMPA probably impact on net DMS fluxes to the marine atmosphere.

Taylor, Barrie F.; Gilchrist, Darrin C.

1991-01-01

237

Molecular identification of mesophilic and psychrotrophic bacteria from raw cow's milk.  

PubMed

The aim of this study was to use molecular techniques to assess the microbiota of eight raw cow's milk samples at biotype and species level. Sixty-six isolates from raw milk samples were screened by Randomly amplified polymorphic DNA-PCR (RAPD-PCR) biotyping and representative strains of RAPD-PCR profiles were identified by 16S rRNA gene sequencing. Pseudomonas spp. were the most commonly occurring contaminants along with Enterobacteriaceae such as Hafnia alvei, Serratia marcescens and Citrobacter freundii. Moreover, Gram-positive isolates belonging to the genera Staphylococcus and Lactococcus were also found. Experiments of growth at different temperatures showed that more than 50% of the Gram-negative isolates could grow at chill temperatures and that 65% of the Pseudomonas spp. strains grew at 7 degrees C within 5 days. Only 13 Gram-negative isolates displayed proteolytic activity on milk agar, suggesting that not all the biotypes of milk contaminating species are able to perform this spoilage-associated activity. Among the Gram negative, the proteolytic strains were mainly Peudomonas spp. that displayed the activity at both 7 degrees C and 20 degrees C. A reliable molecular identification of raw milk microbiota is important for the study of the microbiological quality of raw milks and for the assessment of the ecology at species level in order to develop improved systems, preventing contamination and having the best conditions for the storage of milk. PMID:19171267

Ercolini, Danilo; Russo, Federica; Ferrocino, Ilario; Villani, Francesco

2008-10-11

238

Lactic acid bacteria of meat and meat products  

Microsoft Academic Search

When the growth of aerobic spoilage bacteria is inhibited, lactic acid bacteria may become the dominant component of the microbial flora of meats. This occurs with cured meats and with meats packaged in films of low gas permeability. The presence of a flora of psychrotrophic lactic acid bacteria on vacuum-packaged fresh chilled meats usually ensures that shelf-life is maximal. When

Aubrey F. Egan

1983-01-01

239

Aerobic landfill bioreactor  

SciTech Connect

The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120 F and 140 F in steady state.

Hudgins, M.P.; Bessette, B.J.; March, J.; McComb, S.T.

2000-02-15

240

Low-Impact Aerobics: Better than Traditional Aerobic Dance?  

ERIC Educational Resources Information Center

|A form of dance exercise called low-impact aerobics is being touted as a misery-free form of aerobic dance. Because this activity is relatively new, the exact kinds and frequencies of injuries are not known and the fitness benefits have not been examined. (MT)|

Koszuta, Laurie Einstein

1986-01-01

241

The role of anaerobic bacteria in chronic suppurative otitis media in children: Implications for medical therapy  

Microsoft Academic Search

This review describes the microbiology, diagnosis and medical management of chronic suppurative otitis media (CSOM) in children highlighting the role of anaerobic bacteria. In studies that employed adequate method for recovery of anaerobic bacteria polymicrobial aerobic and anaerobic flora was isolated from over half of the children with CSOM. The predominant aerobic isolates were Staphylococcus aureus and Pseudomonas aeruginosa and

Itzhak Brook

2008-01-01

242

Exercise, Animal Aerobics, and Interpretation?  

ERIC Educational Resources Information Center

|Describes an aerobic activity set to music for children that mimics animal movements. Example exercises include walking like a penguin or jumping like a cricket. Stresses basic aerobic principles and designing the program at the level of children's motor skills. Benefits include reaching people who normally don't visit nature centers, and…

Oliver, Valerie

1996-01-01

243

Aerobic glycolysis during lymphocyte proliferation  

Microsoft Academic Search

GLYCOLYSIS, for most mammalian cells, is only a prelude to the complete respiratory oxidation of glucose. Lactate production is usually barely, if at all, detectable in aerobic conditions1. Consequently, when Warburg2,3 observed that various tumours showed active aerobic glycolysis, he postulated that defective tumour cell respiration was the reason and was, moreover, the basic difference between normal and cancer cells.

Tingchung Wang; Cathleen Marquardt; John Foker

1976-01-01

244

Interconversion of Functional Motions between Mesophilic and Thermophilic Adenylate Kinases  

PubMed Central

Dynamic properties are functionally important in many proteins, including the enzyme adenylate kinase (AK), for which the open/closed transition limits the rate of catalytic turnover. Here, we compare our previously published coarse-grained (double-well G?) simulation of mesophilic AK from E. coli (AKmeso) to simulations of thermophilic AK from Aquifex aeolicus (AKthermo). In AKthermo, as with AKmeso, the LID domain prefers to close before the NMP domain in the presence of ligand, but LID rigid-body flexibility in the open (O) ensemble decreases significantly. Backbone foldedness in O and/or transition state (TS) ensembles increases significantly relative to AKmeso in some interdomain backbone hinges and within LID. In contact space, the TS of AKthermo has fewer contacts at the CORE-LID interface but a stronger contact network surrounding the CORE-NMP interface than the TS of AKmeso. A “heated” simulation of AKthermo at 375K slightly increases LID rigid-body flexibility in accordance with the “corresponding states” hypothesis. Furthermore, while computational mutation of 7 prolines in AKthermo to their AKmeso counterparts produces similar small perturbations, mutation of these sites, especially positions 8 and 155, to glycine is required to achieve LID rigid-body flexibility and hinge flexibilities comparable to AKmeso. Mutating the 7 sites to proline in AKmeso reduces some hinges' flexibilities, especially hinge 2, but does not reduce LID rigid-body flexibility, suggesting that these two types of motion are decoupled in AKmeso. In conclusion, our results suggest that hinge flexibility and global functional motions alike are correlated with but not exclusively determined by the hinge residues. This mutational framework can inform the rational design of functionally important flexibility and allostery in other proteins toward engineering novel biochemical pathways.

Daily, Michael D.; Phillips, George N.; Cui, Qiang

2011-01-01

245

Comparison of laboratory-scale thermophilic biofilm and activated sludge processes integrated with a mesophilic activated sludge process  

Microsoft Academic Search

A combined thermophilic–mesophilic wastewater treatment was studied using a laboratory-scale thermophilic activated sludge process (ASP) followed by mesophilic ASP or a thermophilic suspended carrier biofilm process (SCBP) followed by mesophilic ASP, both systems treating diluted molasses (dilution factor 1:500 corresponding GF\\/A-filtered COD (CODfilt) of 1900±190 mgl?1). With hydraulic retention times (HRTs) of 12–18 h the thermophilic ASP and thermophilic SCBP

J. Suvilampi; A. Lehtomäki; J. Rintala

2003-01-01

246

The detrital food chain based on seaweeds. I. Bacteria associated with the surface of Laminaria fronds  

Microsoft Academic Search

The bacteria associated with the surface of fronds of the sublittoral brown alga Laminaria longicruris were investigated over a 13-month period on the coast of Nova Scotia (Canada). A psychrophilic population was found to be associated with the frond during the winter and a mesophilic population with the decaying frond during the summer. Numbers of psychrophiles varied inversely with ambient

R. A. Laycock

1974-01-01

247

Changes in microbial populations on fresh cut spinach  

Microsoft Academic Search

The microbial populations found on fresh-cut spinach leaves that were stored in gas permeable bags at 10 °C for 12 days were examined and identified. The microorganisms consisted of mesophilic aerobic bacteria, psychrotrophic bacteria, Pseudomonadaceae, Enterobacteriaceae, Micrococcaceae, lactic acid bacteria and yeasts. Populations of mesophiles, psychrotrophs, Pseudomonadaceae and Enterobacteriaceae increased sharply during the storage period. The initial populations were 107,

I. Babic; S. Roy; A. E. Watada; W. P. Wergin

1996-01-01

248

Biological Control of Phytopathogenic Fungi by Aerobic Endospore-Formers  

Microsoft Academic Search

\\u000a Biological control is an environmentally friendly alternative to using fungicides for the control of phytopathogenic fungi,\\u000a and it is likely to gain wider use in the future. The use of aerobic endospore-forming bacteria as biocontrol agents for fungal\\u000a plant diseases is increasing throughout the world, as this control strategy gradually gains acceptance. Various free-living\\u000a and endophytic Bacillus species have been

Alejandro Pérez-García; Diego Romero; Houda Zeriouh; Antonio de Vicente

249

Aerobic methanotrophs from the coastal thermal springs of Lake Baikal  

Microsoft Academic Search

The number, activity, and diversity of aerobic methanotrophic bacteria in the sediments of three coastal thermal springs of\\u000a Lake Baikal were analyzed. The average number of methanotrophs was 103–104 cells per 1 cm3 of sediment. The highest number of methanotrophs (108 cells\\/cm3 of silt) and the highest potential rate of methane uptake [7.7 nmol CH4\\/(cm3 day)] were revealed in sediments

T. S. Zelenkina; B. Ts. Eshinimayev; O. P. Dagurova; N. E. Suzina; B. B. Namsarayev; Yu. A. Trotsenko

2009-01-01

250

Plant Growth and Morphogenesis in vitroIs Promoted by Associative Methylotrophic Bacteria  

Microsoft Academic Search

The effects of aerobic methylotrophic bacteria Methylovorus mayson growth and morphogenesis were studied in in vitropropagated tobacco, potato, and flax. Colonization of plant explants with the methylo-trophic bacteria led to the stable association of bacteria and plants and enhanced the growth and the capacity of the latter for regeneration and root formation. When colonized by the methylotrophic bacteria, the rootless

M. A. Kalyaeva; N. S. Zacharchenko; N. V. Doronina; E. B. Rukavtsova; E. G. Ivanova; V. V. Alekseeva; Yu. A. Trotsenko; Ya. I. Bur'yanov

2001-01-01

251

BIOFILMS AND ADHESION PROTEIN IN ANAEROBE BACTERIA ISOLATED FROM MEXICAN GAS PIPELINES  

Microsoft Academic Search

The pipelines plugging, souring oil and corrosion by microorganisms are a big problem in the oil industry. The pipelines plugging is produced by bacterial consortium that can produce biofilms. In these attached microbial populations, aerobes bacteria growth in the superficial layers, and, anaerobes bacteria (fermenters, sulfate-reducing bacteria, tiosulfate-reducing bacteria, methanogen growth adhered to metal. In industrial areas, surfactants, emulsifiers and

252

Competitive Oxidation of Volatile Fatty Acids by Sulfate and Nitrate-Reducing Bacteria from an Oil Field in Argentina  

Microsoft Academic Search

Acetate, propionate, and butyrate, collectively referred to as volatile fatty acids (VFA), are considered among the most important electron donors for sulfate-reducing bacteria (SRB) and heterotrophic nitrate-reducing bacteria (hNRB) in oil fields. Samples obtained from a field in the Neuquen Basin, western Argentina, had significant activity of mesophilic SRB, hNRB, and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). In microcosms, containing VFA (3

Aleksandr A. Grigoryan; Sabrina L. Cornish; Brenton Buziak; Shiping Lin; Adriana Cavallaro; Joseph J. Arensdorf; Gerrit Voordouw

2008-01-01

253

Aerobic granular sludge: recent advances.  

PubMed

Aerobic granulation, a novel environmental biotechnological process, was increasingly drawing interest of researchers engaging in work in the area of biological wastewater treatment. Developed about one decade ago, it was exciting research work that explored beyond the limits of aerobic wastewater treatment such as treatment of high strength organic wastewaters, bioremediation of toxic aromatic pollutants including phenol, toluene, pyridine and textile dyes, removal of nitrogen, phosphate, sulphate and nuclear waste and adsorption of heavy metals. Despite this intensive research the mechanisms responsible for aerobic granulation and the strategy to expedite the formation of granular sludge, and effects of different operational and environmental factors have not yet been clearly described. This paper provides an up-to-date review on recent research development in aerobic biogranulation technology and applications in treating toxic industrial and municipal wastewaters. Factors affecting granulation, granule characterization, granulation hypotheses, effects of different operational parameters on aerobic granulation, response of aerobic granules to different environmental conditions, their applications in bioremediations, and possible future trends were delineated. The review attempts to shed light on the fundamental understanding in aerobic granulation by newly employed confocal laser scanning microscopic techniques and microscopic observations of granules. PMID:18573633

Adav, Sunil S; Lee, Duu-Jong; Show, Kuan-Yeow; Tay, Joo-Hwa

2008-05-19

254

Cultivation of aerobic granular sludge in sequencing batch reactor with short cycle  

Microsoft Academic Search

In a sequencing batch reactor (SBR) with 2.5h operation cycle, aerobic granular sludge (AGS) was developed successfully. The main diameter and sludge volume index (SVI) of AGS cultivated were 1~3 mm and 33 ml g-1. There were significant effects of pH value on aerobic granulation. The dosage of 300 mgNaHCO3 l-1 to influent could avoid the overgrowth of filamentous bacteria

Huaji Ma; Shuting Zhang

2010-01-01

255

Dynamics of nitrification and denitrification in root- oxygenated sediments and adaptation of ammonia-oxidizing bacteria to low-oxygen or anoxic habitats  

Microsoft Academic Search

Oxygen-releasing plants may provide aerobic niches in anoxic sediments and soils for ammonia-oxidizing bacteria, The oxygen- releasing, aerenchymatous emergent macrophyte Glycerin maxima had a strong positive effect on numbers and activities of the nitrifying bacteria in its root zone in spring and early summer, The stimulation of the aerobic nitrifying bacteria in the freshwater sediment, ascribed to oxygen release by

PAUL L. E. BODELIER; JACOBUS A. LIBOCHANT; CEES W. P. M. BLOM; H. J. Laanbroek

1996-01-01

256

Effect of high temperature on bacterial community dynamics in anaerobic acidogenesis using mesophilic sludge inoculum.  

PubMed

In this study, we investigated the microbial community dynamics in thermal acidogenesis using mesophilic sludge. From the result of optimization with a response surface methodology, the acidogenic optimum conditions predicted were a hydraulic retention time of 2.0 days and 51 degrees C. Denaturing gradient gel electrophoresis (DGGE) profiles shows that the monitored bacterial community present consists of Pseudomonas mendocina, Bacillus halodurans, Clostridium hastiforme, Gracilibacter thermotolerans, and Thermomonas haemolytica. Among these, B. halodurans, G. thermotolerans, and T. haemolytica are reported to ferment carbohydrates thermotolerantly. In contrast, P. mendocina disappeared in the acidogenesis process because of its mesophilicity. In addition, C. hastiforme, G. thermotolerans originating from mesophilic anaerobic sludge were detected in the thermal acidogenesis. Based on this finding, we inferred that most thermophiles detected as DGGE bands could grow catalyzing carbohydrates metabolism in swine wastewater to produce volatile fatty acids thermotolerantly. PMID:19362824

Kim, Woong; Hwang, Kwanghyun; Shin, Seung Gu; Lee, Seungyong; Hwang, Seokhwan

2009-04-11

257

Differentiation of Methanosaeta concilii and Methanosarcina barkeri in Anaerobic Mesophilic Granular Sludge by Fluorescent In Situ Hybridization and Confocal Scanning Laser Microscopy†  

PubMed Central

Oligonucleotide probes, designed from genes coding for 16S rRNA, were developed to differentiate Methanosaeta concilii, Methanosarcina barkeri, and mesophilic methanogens. All M. concilii oligonucleotide probes (designated MS1, MS2, and MS5) hybridized specifically with the target DNA, but MS5 was the most specific M. concilii oligonucleotide probe. Methanosarcina barkeri oligonucleotide probes (designated MB1, MB3, and MB4) hybridized with different Methanosarcina species. The MB4 probe specifically detected Methanosarcina barkeri, and the MB3 probe detected the presence of all mesophilic Methanosarcina species. These new oligonucleotide probes facilitated the identification, localization, and quantification of the specific relative abundance of M. concilii and Methanosarcina barkeri, which play important roles in methanogenesis. The combined use of fluorescent in situ hybridization with confocal scanning laser microscopy demonstrated that anaerobic granule topography depends on granule origin and feeding. Protein-fed granules showed no layered structure with a random distribution of M. concilii. In contrast, a layered structure developed in methanol-enriched granules, where M. barkeri growth was induced in an outer layer. This outer layer was followed by a layer composed of M. concilii, with an inner core of M. concilii and other bacteria.

Rocheleau, Sylvie; Greer, Charles W.; Lawrence, John R.; Cantin, Christiane; Laramee, Louise; Guiot, Serge R.

1999-01-01

258

Differentiation of Methanosaeta concilii and Methanocarcina barkeri in anaerobic mesophilic granular sludge by fluorescent in situ hybridization and confocal scanning laser microscopy  

SciTech Connect

Oligonucleotide probes, designed from genes coding for 16S rRNA, were developed to differentiate Methanosaeta concilii, Methanosarcina barkeri, and mesophilic methanogens. All M. concilii oligonucleotide probes (designated MS1, MS2, and MS5) hybridized specifically with the target DNA, but MS5 was the most specific M. concilii oligonucleotide probe. Methanosarcina barkeri oligonucleotide probes (designated MB1, MB3, and MB4) hybridized with different Methanosarcina species. The MB4 probe specifically detected Methanosarcina barkeri, and the MB3 probe detected the presence of al mesophilic Methanosarcina species. These new oligonucleotide probes facilitated the identification, localization, and quantification of the specific relative abundance of M. concilii and Methanosarcina barkeri, which play important roles in methanogenesis. The combined use of fluorescent in situ hybridization with confocal scanning laser microscopy demonstrated that anaerobic granule topography depends on granule origin and feeding. Protein-fed granules showed no layered structure with a random distribution of M. concilii. In contrast, a layered structure developed in methanol-enriched granules, where M. barkeri growth was induced in an outer layer. This outer layer was followed by a layer composed of M. concilii, with an inner core of M. concilii and other bacteria.

Rocheleau, S.; Greer, C.W.; Cantin, C.; Laramee, L.; Guiot, S.R. [National Research Council Canada, Montreal, Quebec (Canada). Biotechnology Research Inst.; Lawrence, J.R. [National Water Research Inst., Saskatoon, Saskatchewan (Canada)

1999-05-01

259

The carotenoids of photosynthetic bacteria  

Microsoft Academic Search

1.Three strains ofR. palustris synthesize lycopene,P 481, spirilloxanthin, lycoxanthin, hydroxy-P 481 and “demethylated” spirilloxanthin under both aerobic and anaerobic conditions. One strain (8289) is characterized by a high relative concentration of lycoxanthin.2.R. capsulatus andR. gelatinosa synthesize lycopene,Y, R, hydroxy-Y and hydroxy-R; the latter produces in addition spirilloxanthin and a new pigment,P 512. In both bacteriaY and hydroxy-Y predominate in anaerobic

T. W. Goodwin

1956-01-01

260

Community Size and Metabolic Rates of Psychrophilic Sulfate-Reducing Bacteria in Arctic Marine Sediments  

PubMed Central

The numbers of sulfate reducers in two Arctic sediments with in situ temperatures of 2.6 and ?1.7°C were determined. Most-probable-number counts were higher at 10°C than at 20°C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than their mesophilic counterparts at similarly low temperatures.

Knoblauch, Christian; J?rgensen, Bo Barker; Harder, Jens

1999-01-01

261

MOTILE MARINE BACTERIA I.  

PubMed Central

Leifson, Einar (Loyola University, Chicago, Ill.), B. J. Cosenza, R. Murchelano, and R. C. Cleverdon. Motile marine bacteria. I. Techniques, ecology, and general characteristics. J. Bacteriol. 87:652–666. 1964.—Aerobic, heterotrophic bacteria were isolated from the waters of the Long Island Sound, Narragansett Bay, Atlantic Ocean, and from the intestine of a variety of marine animals found along the shore of the Long Island Sound. A total of about 600 cultures of motile bacteria were studied morphologically and physiologically, with special emphasis on flagellar characteristics. The great majority of the bacteria isolated from the water were polar flagellate, nonfermentative, nonpigmented, and gramnegative. Most of these were straight, capsulated rods, but a considerable number were curved like vibrios. Yellow-pigmented isolates were often nonmotile, and the motile forms were most frequently subpolar flagellate. Several rosette-forming bacteria, including Caulobacter species, were isolated. Two typical spirilla and one flagellated coccus were found. Peritrichous flagellate bacteria, both gram-positive and gram-negative, were rare except in bottom mud. The normal intestinal flora of marine animals, such as fish and shellfish, consisted of polar flagellate, fermentative, non-pigmented, gram-negative, straight rods. Curved forms, like vibrios, were less common. Polar multitrichous flagellate forms were not uncommon and included all the luminescent types isolated. A considerable proportion of the polar monotrichous flagellate rods swarmed over the surface of agar media. When grown on solid media, all of these showed mixed polar and lateral flagellation; in liquid media, mainly polar flagellation was found. The ecology and general taxonomy of marine bacteria are discussed. Images

Leifson, Einar; Cosenza, B. J.; Murchelano, R.; Cleverdon, R. C.

1964-01-01

262

Effect of ammonia on the anaerobic degradation of protein by a mesophilic and thermophilic biowaste population  

Microsoft Academic Search

The influence of ammonia on the anaerobic degradation of peptone by mesophilic and thermophilic populations of biowaste was\\u000a investigated. For peptone concentrations from 5?g?l?1 to 20?g?l?1 the mesophilic population revealed a higher rate of deamination than the thermophilic population, e.g. 552?mg?l?1?day?1 compared to 320?mg?l?1?day?1 at 10?g?l?1 peptone. The final degree of deamination of the thermophilic population was, however, higher: 102

C. Gallert; S. Bauer; J. Winter

1998-01-01

263

Mesophilic microorganisms and endotoxin levels on developing cotton plants.  

PubMed

Healthy cotton leaf, bract, fiber and soil were collected twice each week during growing season. These samples were studied to determine the epiphytic total and gram-negative bacterial (GNB) populations and endotoxin levels from seedling development to harvest. Since bract is a significant trash component of raw cotton, a study of the epiphytic bract fungi was performed also. Bract and soil had the highest total bacterial count (TBC) until senescence, when the bract count increased significantly over that of the soil. Leaf TBC was usually third while fiber had the least TBC. Leaf senescence did not result in an increase in TBC as with bract. GNB counts paralleled, but were approximately 10-fold lower than that of the TBC. Enterobacter agglomerans was the most predominant bacterium on leaf and bract. Gram-positive rods were the most common bacteria on fiber with E. agglomerans second. Gram-positive rods were by far the predominant species in soil. Senescence affected the population levels of the various genera on leaf and bract. Endotoxin varied greatly for all sample types. Soil usually gave the highest amounts, followed by bract, fiber leaf surface. Statistical analysis showed some minor correlations between the presence of certain bacteria with other bacteria. No correlations were found between weather data and bacterial types present or endotoxin levels. The epiphytic fungal population on bract was studied through the growing season. Though different genera appeared, the predominant genus throughout the study was Cladosporium. PMID:3751893

DeLucca, A J; Palmgren, M S

1986-08-01

264

Aerobic and anaerobic microorganisms in tubercles of the Columbus, Ohio, water distribution system.  

PubMed Central

Aerobic and anaerobic microorganisms were enumerated in tubercles collected from sections of the water distribution pipeline in the Columbus, Ohio, metropolitan area. Coliform bacteria were not detected in the tubercles examined. Sulfate-reducing bacteria were detected in 80% of the samples. Nitrate-reducing heterotrophs were present in all samples. The results, including plate counts of aerobic heterotrophs, indicated variation in bacterial densities depending on the tubercle sample and fraction examined. The associations among the viable counts obtained by the different culture methods were analyzed statistically, using three methods (Pearson, Spearman, and Kendall).

Tuovinen, O H; Hsu, J C

1982-01-01

265

Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken  

NASA Astrophysics Data System (ADS)

Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 °C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

Fallah, Aziz A.; Siavash Saei-Dehkordi, S.; Rahnama, Mohammad

2010-10-01

266

Antibacterial effect of plantaricin LP84 on foodborne pathogenic bacteria occurring as contaminants during idli batter fermentation  

Microsoft Academic Search

Idli, a traditional cereal\\/legume-based naturally fermented steamed product with soft and spongy texture is highly popular and widely consumed in India. The inherent viable bacterial populations of mesophilic aerobes and lactics in idli batter increased in their numbers with time at 35 °C, reaching numbers in the range of 13 to 15 log10 CFU g-1. Simultaneously, the pH level decreased

Yusuf Hasan Jama; M. C. Varadaraj

1999-01-01

267

Interaction and nanotoxic effect of ZnO and Ag nanoparticles on mesophilic and halophilic bacterial cells.  

PubMed

The toxicity of two commonly used nanoparticles, silver and zinc oxide on mesophilic and halophilic bacterial cells has been investigated. Enterobacter sp., Marinobacter sp., Bacillus subtilis, halophilic bacterium sp. EMB4, were taken as model systems. The nanotoxicity was more pronounced on Gram negative bacteria. ZnO nanoparticles reduced the growth of Enterobacter sp. by 50%, while 80% reduction was observed in halophilic Marinobacter sp. In case of halophiles, this may be attributed to higher content of negatively charged cardiolipins on their cell surface. Interestingly, bulk ZnO exerted minimal reduction in growth. Ag nanoparticles were similarly cytotoxic. Nanotoxicity towards Gram positive cells was significantly less, possibly due to presence of thicker peptidoglycan layer. The bacterium nanoparticle interactions were probed by electron microscopy and energy dispersive X-ray analysis. The results indicated electrostatic interactions between nanoparticles and cell surface as the primary step towards nanotoxicity, followed by cell morphological changes, increase in membrane permeability and their accumulation in the cytoplasm. PMID:20797851

Sinha, Rajeshwari; Karan, Ram; Sinha, Arvind; Khare, S K

2010-08-04

268

The effect of digestion and dewatering on sudden increases and regrowth of indicator bacteria after dewatering.  

PubMed

Several investigators have reported higher densities of indicator bacteria after dewatering of anaerobically digested biosolids. The increases appear to occur at two points in the biosolids process: the first, referred to as "sudden increase", occurs immediately after dewatering; the second, "regrowth", occurs during storage over longer periods. The objectives of this study were to examine the effect of digestion and dewatering processes on sudden increase and regrowth of fecal coliform and E. coli. Samples were collected from five thermophilic and five mesophilic digestion processes, with either centrifuge or belt filter press dewatering. Sudden increase typically was observed in the thermophilic processes with centrifuge dewatering and was not observed in the mesophilic processes with either centrifuge or belt filter press dewatering. Regrowth was observed in both thermophilic and mesophilic processes with centrifuge dewatering but not belt filter press dewatering. PMID:22073724

Chen, Yen-Chih; Murthy, Sudhir N; Hendrickson, Donald; Araujo, Gordon; Higgins, Matthew J

2011-09-01

269

The mesophilic and thermophilic anaerobic digestion of coffee waste containing coffee grounds  

Microsoft Academic Search

The anaerobic digestion of waste water containing significant levels of coffee grounds was assessed in mesophilic and thermophilic batch studies and CSTRs fed daily. A 58% reduction in VS was seen in both batch studies. Proximate compositional analysis showed that the waste had a high lipid component (26–33%). Levels of lipid, hemicellulose, ?-cellulose and lignin were determined before and after

Richard M. Dinsdale; Freda R. Hawkes; Dennis L. Hawkes

1996-01-01

270

Effect of high temperature on bacterial community dynamics in anaerobic acidogenesis using mesophilic sludge inoculum  

Microsoft Academic Search

In this study, we investigated the microbial community dynamics in thermal acidogenesis using mesophilic sludge. From the result of optimization with a response surface methodology, the acidogenic optimum conditions predicted were a hydraulic retention time of 2.0 days and 51°C. Denaturing gradient gel electrophoresis (DGGE) profiles shows that the monitored bacterial community present consists of Pseudomonas mendocina, Bacillus halodurans, Clostridium

Woong Kim; Kwanghyun Hwang; Seung Gu Shin; Seungyong Lee; Seokhwan Hwang

2010-01-01

271

PHYLOGENETIC DIVERSITY AND GROWTH DYNAMICS OF MESOPHILIC SOIL CRENARCHAEOTA IN ENRICHMENT CULTURE STUDIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous studies have established the widespread distribution of mesophilic members of the division Crenarchaeota (domain Archaea). Currently, the metabolic properties of these ubiquitous microorganisms are unknown, in part due to the fact that attempts to isolate and grow them in laboratory culture...

272

Draft Genome Sequence of the Cellulolytic, Mesophilic, Anaerobic Bacterium Clostridium termitidis Strain CT1112 (DSM 5398)  

PubMed Central

Here, we report the draft genome sequence of Clostridium termitidis strain CT1112 (DSM 5398), a mesophilic, cellulolytic bacterium that can utilize a variety of sugars, as well as pure cellulose, as a sole carbon source; it also synthesizes fermentation end products with potential industrial applications.

Lal, Sadhana; Ramachandran, Umesh; Zhang, Xiangli; Munir, Riffat; Sparling, Richard

2013-01-01

273

Genome sequence of the cellulosome-producing mesophilic organism Clostridium cellulovorans 743B.  

PubMed

Clostridium cellulovorans 743B was isolated from a wood chip pile and is an anaerobic and mesophilic spore-forming bacterium. This organism degrades native substrates in soft biomass such as corn fiber and rice straw efficiently by producing an extracellular enzyme complex called the cellulosome. Here we report the genome sequence of C. cellulovorans 743B. PMID:19948806

Tamaru, Yutaka; Miyake, Hideo; Kuroda, Kouichi; Nakanishi, Akihito; Kawade, Yujiro; Yamamoto, Kousuke; Uemura, Masaaki; Fujita, Yasuhiro; Doi, Roy H; Ueda, Mitsuyoshi

2009-11-30

274

Single step conversion of cellulose to ethanol by a mesophilic coculture  

Microsoft Academic Search

A coculture consisting of two mesophilic anaerobes, produced about 0.8 mole of ethanol per mole of cellulose from a variety of cellulosic materials. The non-cellulolytic member of this coculture, Clostridium saccharolyticum sp. nov. converted glucose and xylose to ethanol and acetic acid in ratios over 4 to 1.

A. W. Khan; William D. Murray

1982-01-01

275

Continuous dark fermentative hydrogen production by mesophilic microflora: Principles and progress  

Microsoft Academic Search

Continuous, dark fermentative hydrogen production technology using mixed microflora at mesophilic temperatures may be suitable for commercial development. Clostridial-based cultures from natural sources have been widely used, but more information on the need for heat treatment of inocula and conditions leading to germination and sporulation are required. The amount of nutrients given in the literature vary widely. Hydrogen production is

Freda R. Hawkes; Ines Hussy; Godfrey Kyazze; Richard Dinsdale; Dennis L. Hawkes

2007-01-01

276

Draft Genome Sequence of the Cellulolytic, Mesophilic, Anaerobic Bacterium Clostridium termitidis Strain CT1112 (DSM 5398).  

PubMed

Here, we report the draft genome sequence of Clostridium termitidis strain CT1112 (DSM 5398), a mesophilic, cellulolytic bacterium that can utilize a variety of sugars, as well as pure cellulose, as a sole carbon source; it also synthesizes fermentation end products with potential industrial applications. PMID:23704187

Lal, Sadhana; Ramachandran, Umesh; Zhang, Xiangli; Munir, Riffat; Sparling, Richard; Levin, David B

2013-05-23

277

COMPARATIVE EVALUATION OF MESOPHILIC AND THERMOPHILIC DIGESTION - PHASE I. TEMPERATURE TRANSITION STUDIES  

EPA Science Inventory

As part of a larger study on the comparison between mesophilic and thermophilic anaerobic digestion, a study of the operation of anaerobic systems under temperature transition was conducted. Systems seeded with domestic sewage sludge, but subsequently fed a chemically defined com...

278

COMPARATIVE EVALUATION OF MESOPHILIC AND THERMOPHILIC DIGESTION - PHASE II. STEADY STATE STUDIES  

EPA Science Inventory

A study of the relative performance of anaerobic digestion systems under mesophilic and thermophilic conditions was conducted. Fifty liter laboratory scale digesters were fed primary sludge from the Allentown, PA Waste Water Treatment Plant. Long-term, steady-state performance da...

279

COMPARATIVE EVALUATION OF MESOPHILIC AND THERMOPHILIC ANAEROBIC DIGESTION. PHASE 2. STEADY STATE STUDIES  

EPA Science Inventory

A study was conducted of the relative performance of anaerobic digestion systems under mesophilic and thermophilic conditions. Fifty liter laboratory scale digesters were fed primary sludge from the Allentown, PA Waste Water Treatment Plant. Long-term, steady-state performance da...

280

Complete Genome Sequence of the Piezophilic, Mesophilic, Sulfate-Reducing Bacterium Desulfovibrio hydrothermalis AM13(T.).  

PubMed

Desulfovibrio hydrothermalis AM13(T) is a piezophilic, mesophilic, hydrogenotrophic sulfate-reducing bacterium collected from a deep-sea hydrothermal chimney on the East Pacific Rise (2,600 m depth, 13°N). We report the genome sequence of this bacterium, which includes a 3,702,934-bp chromosome and a circular plasmid of 5,328 bp. PMID:23469349

Ji, Boyang; Gimenez, Gregory; Barbe, Valérie; Vacherie, Benoît; Rouy, Zoé; Amrani, Amira; Fardeau, Marie-Laure; Bertin, Philippe; Alazard, Didier; Leroy, Sabine; Talla, Emmanuel; Ollivier, Bernard; Dolla, Alain; Pradel, Nathalie

2013-02-21

281

Alternatives for energy production in aerobic wastewater treatment facilities.  

PubMed

Using technologies such as anaerobic digestion for energy generation from wastewater demands a change in infrastructure that several treatment works are not prepared to immediately implement. This works explores the use of energy production technologies to increase the sustainability of conventional aerobic wastewater treatment plants. The first option considered sludge (a by-product from wastewater treatment) as raw material for biodiesel production as Fatty Acid Methyl Esters (FAME). The second option consisted of the addition of microalgae during aerobic wastewater treatment and subsequent harvesting of combined microalgae-sludge to produce biodiesel. Results showed that microalgae were able to grow in aerobic wastewater treatment reactors, reaching maximum growth after 6 days. The use of microalgae did not statistically affect chemical oxygen demand removal but provided benefits on ammonia removal (100% removal vs 68 ± 9% when microalgae were not added). Activated sludge contained fewer lipids (13 ± 3%, by dry weight) than the microalgae-sludge mixture (20.8 ± 4.5%). Hence, FAME production when using microalgae-sludge was higher (51.12 ± 12 mg of FAME/g of dry microalgae-sludge) than when using activated sludge (25.6 ± 7 mg of FAME/g of dry activated sludge). This work showed that producing biodiesel from microalgae grown in conjunction with bacteria during aerobic wastewater treatment can reduce energy use and carbon emissions produced by 18.6 and 26.5%, respectively. PMID:23787329

Velasquez-Orta, Sharon B

2013-01-01

282

Methylophilus: a New Genus of Methanol-Utilizing Bacteria  

Microsoft Academic Search

A new genus, Methyluphilus, and species of restricted facultative methanol-utilizing bacteria are described. These bacteria are aerobic gram-negative rods that occur singly and in pairs. In addition to methanol and glucose, a limited range of other carbon compounds including fructose and methylamines may be used as the sole carbon and energy source. The fatty acid composition is primarily of the

OWEN JENKINS; DAVID BYROM; DOROTHY JONES

283

[Antibiotic sensitivity of the main opportunistic pathogenic aerobic bacteria].  

PubMed

Antibiotic sensitivity of 1421 strains of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa and Klebsiella spp. was studied. Gentamicin, levomycetin (chloramphenicol) and ristomycin proved to be the antibiotics of choice in treatment of purulent inflammatory diseases caused by S. epidermidis and S. aureus. For antibiotic therapy of infections caused by gram-negative organisms gentamicin and polymixin might be recommended. PMID:2113800

Minukhin, V V; Tsyganenko, A Ia; Kravtsova, V I; Arkushenko, L L; Stepanenko, T V

1990-03-01

284

Control of urease formation in certain aerobic bacteria  

Microsoft Academic Search

During nitrogen starvation, a 20- to 250-fold increase in specific urease activity was observed in extracts of P. aeruginosa, P. fluorescens, Hydrogenomonas, M. denitrificans, M. cerificans and B. megaterium. In contrast to these species, high levels of urease were observed in P. vulgaris strains and in S. ureae under all growth conditions. No urease was detectable in strains of E.

H. Kaltwasser; J. Krämer; W. R. Conger

1972-01-01

285

Method and Apparatus for Plating and Counting Aerobic Bacteria.  

National Technical Information Service (NTIS)

The patent application describes a method for determining the concentration of an unknown bacterial solution using only a single bacterial growth plate for the determination. The method comprises depositing a varying amount of bacterial solution on the su...

C. Gilchrist

1974-01-01

286

Cellulase system of a free-living, mesophilic clostridium (strain C7).  

PubMed Central

The enzymatic activity responsible for crystalline cellulose degradation (Avicelase activity) by a mesophilic clostridium (strain C7) was present in culture supernatant fluid but was not detected in significant amounts in association with whole cells or in disrupted cells. Cells of the mesophilic clostridium lacked cellulosome clusters on their surface and did not adhere to cellulose fibers. The extracellular cellulase system of the mesophilic clostridium was fractionated by Sephracryl S-300 gel filtration, and the fractions were assayed for Avicelase and carboxymethylcellulase activities. The Avicelase activity coincided with an A280 peak that eluted in the 700,000-Mr region. Nondenaturing polyacrylamide gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the 700,000-Mr fractions showed that Avicelase was present as a multiprotein aggregate that lost the ability to hydrolyze crystalline cellulose when partially dissociated by sodium dodecyl sulfate treatment. Proteins resulting from the partial dissociation of the aggregate retained carboxymethylcellulase activity. An Avicelase-deficient mutant of strain C7 (strain LS), which was not capable of degrading crystalline cellulose, lacked the Avicelase-active 700,000-Mr peak. The results indicated that an extracellular 700,000-Mr multiprotein complex, consisting of at least 15 proteins, is utilized by the mesophilic clostridium for the hydrolysis of crystalline cellulose. At least six different endo-1,4-beta-glucanases may be part of the cellulase system of strain C7. Sephacryl S-300 column fractions, corresponding to an A280 peak in the 130,000-Mr region, contained carboxymethylcellulase-active proteins that may serve as precursors for the assembly of the Avicelase-active complex by the mesophilic clostridium. Images

Cavedon, K; Leschine, S B; Canale-Parola, E

1990-01-01

287

Occurrence and antibiotic resistance of mesophilic Aeromonas in three riverine freshwaters of Marrakech, Morocco.  

PubMed

In order to evaluate the impact of pollution and sewage on the occurrence and antibiotic resistance of mesophilic aeromonads in riverine freshwaters of Marrakech, samples were collected from three rivers (Oukaimeden, Ourika, and Tensift) upstream and downstream from the principal bordering villages. During a 2-year study, indicators of pollution increased dramatically in the downstream waters. Bacterial indicators (faecal coliforms and faecal streptococci) correlated with mesophilic aeromonads only in heavily polluted waters. In low and moderately polluted sources, densities of mesophilic aeromonads were independent of water quality indicators and did not correlate statistically with faecal indicators. Average counts of Aeromonas in low and heavily polluted waters were 2.5 x 10(3) and 2.1 x 10(6) colony forming units per 100 ml, respectively. The biochemical identification of 841 isolates indicated a predominance of A. caviae in heavily and moderately polluted water and sediment. A. hydrophila was dominant only in low polluted waters and when the temperature was below 12 degrees C. High densities of A. sobria were found in low, moderately polluted, or cleaned waters and when the water temperature was above 18 degrees C. All selected isolates (total = 841) were tested for antibiotic susceptibility against 21 antibiotics. Antibiotic resistance frequencies recorded were: ampicillin and amoxicillin, 100%; novobiocin, 96%; cefalotin, 81%; colistin, 72%; sulfamethoxazole, 40%; cefamandole, 37%; polymyxin B, 23%; trimethoprim, 17%; erythromycin, 15%; streptomycin, 8%; amoxicillin-clavulanate, 5%. Resistance to cefotaxime, kanamycin, gentamycin, chloramphenicol, tetracycline, oxytetracycline, nalidixic acid, rifampicin, or trimethoprim-sulfameth-oxazole was found to be <5%. Antibiotic resistance rates did vary according to the source of a strain"s isolation, and high numbers of antibiotic resistant strains were recorded in polluted samples. Since no correlation between mesophilic aeromonads and conventional faecal pollution indicators was observed in low or moderately polluted waters, and since these freshwaters are used for domestic supply, we propose the use of mesophilic aeromonads as complementary water pollution indicators to ensure the safety of water. PMID:12805714

Imziln, B

2001-12-01

288

Lactic acid bacteria and yeasts associated with spontaneous fermentations during the production of sour cassava starch in Brazil  

Microsoft Academic Search

Sour cassava starch is a traditional fermented food used in the preparation of fried foods and baked goods such as traditional cheese breads in Brazil. Thirty samples of sour cassava starch were collected from two factories in the state of Minas Gerais. The samples were examined for the presence of lactic acid bacteria, yeasts, mesophilic microorganisms, Bacillus cereus and faecal

Inayara C. A. Lacerda; Rose L. Miranda; Beatriz M. Borelli; Álvaro C. Nunes; Regina M. D. Nardi; Marc-André Lachance; Carlos A. Rosa

2005-01-01

289

Inactivation kinetics of selected aerobic and anaerobic bacterial spores by pressure-assisted thermal processing  

Microsoft Academic Search

The combined pressure–thermal inactivation kinetics of spores from three strains of anaerobic (Clostridium sporogenes, C. tyrobutylicum, and Thermoanaerobacterium thermosaccharolyticum), and six strains of aerobic (Bacillus amyloliquefaciens and B. sphaericus) bacteria were studied. Spores of these bacteria were prepared in deionized water and treated in a custom-made kinetic tester over various pressure (0.1 and 700 MPa) and thermal (105 and 121 °C) combinations.

J. Ahn; V. M. Balasubramaniam; A. E. Yousef

2007-01-01

290

Characterization of nitrifying granules produced in an aerobic upflow fluidized bed reactor  

Microsoft Academic Search

Since nitrification is the rate-determining step in the biological nitrogen removal from wastewater, many research studies have been conducted on the immobilization of nitrifying bacteria. In this research, granulation of nitrifying bacteria in an aerobic upflow fluidized bed (AUFB) reactor in a nitrification process for inorganic wastewater containing 500g\\/m3 of NH4+-N was investigated. It was observed that spherical, pseudocubic and

Satoshi Tsuneda; Tatsuo Nagano; Tatsuhiko Hoshino; Yoshihiro Ejiri; Naohiro Noda; Akira Hirata

2003-01-01

291

Complete degradation of tetrachloroethene by combining anaerobic dechlorinating and aerobic methanotrophic enrichment cultures  

Microsoft Academic Search

Degradation of tetrachloroethene (perchloroethylene, PCE) was investigated by combining the metabolic abilities of anaerobic\\u000a bacteria, capable of reductive dechlorination of PCE, with those of aerobic methanotrophic bacteria, capable of co-metabolic\\u000a degradation of the less-chlorinated ethenes formed by reductive dechlorination of PCE. Anaerobic communities reductively dechlorinating\\u000a PCE, trichloroethene (TCE) and dichloroethenes were enriched from various sources. The maximum rates of dechlorination

J. Gerritse; V. Renard; J. C. Gottschal; J. Visser

1995-01-01

292

Comparative investigation on microbial community and electricity generation in aerobic and anaerobic enriched MFCs.  

PubMed

This study compared the difference in microbial community and power generation capacity of air-cathode MFCs enriched under anode aerobic and anaerobic conditions. Results showed that MFCs successfully started with continuous air inputting to anode chamber. The aerobic enriched MFC produced comparable and even more electricity with the fuels of acetate, glucose and ethanol compared to the anaerobic MFC when returning to anaerobic condition. The two MFCs showed a slightly different microbial community for anode biofilms (a similarity of 77%), but a highly similar microbial community (a similarity of 97%) for anolyte microbes. The anode biofilm of aerobic enriched MFC showed the presence of some specific bacteria closely related to Clostridium sticklandii, Leucobacter komagatae and Microbacterium laevaniformans. The anaerobic enriched MFC found the presence of a large number of yeast Trichosporon sp. This research demonstrates that it is possible to enrich oxygen-tolerant anode respiring bacteria through purposely aeration in anode chamber. PMID:23196248

Quan, Xiang-chun; Quan, Yan-ping; Tao, Kun; Jiang, Xiao-man

2012-10-23

293

The use of solid peroxides to stimulate growth of aerobic microbes in tundra  

Microsoft Academic Search

Solid peroxides and peroxyhydrates degrade into a basic salt, water, and molecular oxygen when in contact with biologically active soils. Column reactors were used to quantify the extent to which three solid peroxides would stimulate growth of aerobic, heterotrophic bacteria and fungi in contaminated tundra soil. Soils in contact with a peroxide compound were incubated in column reactors at field

Daniel M. White; Robert L. Irvine; Craig R. Woolard

1998-01-01

294

Hospital Wastewater Treatment Using an Integrated Anaerobic Aerobic Fixed Film Bioreactor  

Microsoft Academic Search

The design and operation of wastewater treatment systems for hospital is a challenge for wastewater engineers. In this study, a pilot-scale system integrated anaerobic-aerobic fixed film reactor for hospital wastewater treatment was constructed and its performance was evaluated. The aim of the study was the elimination of organic compounds and a significant reduction of bacteria. The system had been operated

A. Rezaee; M. Ansari; A. Khavanin; A. Sabzali; M. M. Aryan

295

A computer study of the evolution of aerobic heterotrophic bacterial populations in sewage and river waters  

Microsoft Academic Search

The biodegradation of six surface active agents tested. The biochemical characteristics of the aerobic heterotrophic bacteria present in Montpellier waste waters and in Rhône water, before and after degradation, were studied by a standardized microbiological method. Four hundred strains isolated from these populations were compared to 29 reference strains by computer analysis. The reference strains were first grouped in classes

Bernard Baleux

1977-01-01

296

Polyphasic taxonomy of acetic acid bacteria: An overview of the currently applied methodology  

Microsoft Academic Search

Acetic acid bacteria are Gram-negative, obligate aerobic bacteria that have the ability to incompletely oxidize alcohols or sugars to organic acids as end products. They are widespread in nature and most of them are capable to oxidize ethanol as substrate to acetic acid. This characteristic makes that acetic acid bacteria are often involved in foods and beverages, either in a

Ilse Cleenwerck; Paul De Vos

2008-01-01

297

Cellulose fermentation by a coculture of a mesophilic cellulolytic Clostridium and Clostridium acetobutylicum  

SciTech Connect

A coculture of a mesophilic cellulolytic Clostridium with Clostridium acetobutylicum can yield a direct conversion of cellulose into chemicals. In 13 days 30 g/l Solka Floc is degraded and fermented into 14 g/l butyric acid, 4 g/l acetic acid, 3 g/l ethanol, and 1 g/l butanol. A four times higher rate of cellulose hydrolysis than in pure culture of the cellulolytic Clostridium is thus obtained. Fed-batch fermentations of C. acetobutylicum at different glucose feeding rate show that solvents are only produced at a sufficient high rate of glucose supply to the medium. Acids are thus the main products of the coculture because of the limited rate of cellulolysis by the mesophilic strain. 7 references, 5 figures.

Fond, O.; Petitdemange, E.; Petitdemange, H.; Engasser, J.M.

1983-01-01

298

A comparison of mesophilic and thermophilic anaerobic upflow filters treating paper–pulp–liquors  

Microsoft Academic Search

Paper–pulp–liquors and corrugated-paper–pulp–liquors were used as the bases for simulated papermill wastewater and were treated in anaerobic upflow filters which were operated at mesophilic (35°C) and thermophilic (55°C) temperatures. The hydraulic retention time (HRT) ranged from 11.7 to 26.2 h with organic loading rates (OLR) of 1.70–3.87 g\\/l per day. With the paper–pulp–liquors, the thermophilic digester showed significant increases in

J.-H Ahn; C. F Forster

2002-01-01

299

Cellulose fermentation by a coculture of a mesophilic cellulolytic Clostridium and Clostridium acetobutylicum  

Microsoft Academic Search

A coculture of a mesophilic cellulolytic Clostridium with Clostridium acetobutylicum can yield a direct conversion of cellulose into chemicals. In 13 days 30 g\\/l Solka Floc is degraded and fermented into 14 g\\/l butyric acid, 4 g\\/l acetic acid, 3 g\\/l ethanol, and 1 g\\/l butanol. A four times higher rate of cellulose hydrolysis than in pure culture of the

O. Fond; E. Petitdemange; H. Petitdemange; J. M. Engasser

1983-01-01

300

Characterization of the cellulolytic and hydrogen-producing activities of six mesophilic Clostridium species  

Microsoft Academic Search

Aims: To characterize cellulolytic, hydrogen-producing clostridia on a compar- able basis. Methods and Results: H2 production from cellulose by six mesophilic clostridia was characterized in standardized batch experiments using MN301 cellulose, Avicel and cellobiose. Daily H2 production, substrate degradation, biomass pro- duction and the end-point distribution of soluble fermentation products varied with species and substrates. All species produced a significant

Z. Ren; T. E. Ward; B. E. Logan; J. M. Regan

2007-01-01

301

Differences in amino acids composition and coupling patterns between mesophilic and thermophilic proteins  

Microsoft Academic Search

Summary.  Thermophilic proteins show substantially higher intrinsic thermal stability than their mesophilic counterparts. Amino acid\\u000a composition is believed to alter the intrinsic stability of proteins. Several investigations and mutagenesis experiment have\\u000a been carried out to understand the amino acid composition for the thermostability of proteins. This review presents some generalized\\u000a features of amino acid composition found in thermophilic proteins, including an

X.-X. Zhou; Y.-B. Wang; Y.-J. Pan; W.-F. Li

2008-01-01

302

Enhancement of transglycosylation activity by construction of chimeras between mesophilic and thermophilic ?-glucosidase  

Microsoft Academic Search

The family 3 ?-glucosidase from Thermotoga maritima is a highly thermostable enzyme (85°C) that displays transglycosylation activity. In contrast, the ?-glucosidase from Cellvibrio gilvus is mesophilic (35°C) and displays no such transglycosylation activity. Both enzymes consist of two domains, an N-terminal and a C-terminal domain, and the amino acid identities between the two enzymes in these domains are 32.4 and

Kshamata Goyal; Bong Jo Kim; Jong-Deog Kim; Yeon-Kye Kim; Motomitsu Kitaoka; Kiyoshi Hayashi

2002-01-01

303

Dynamics and unfolding pathways of a hyperthermophilic and a mesophilic rubredoxin.  

PubMed Central

Molecular dynamics simulations in solution are performed for a rubredoxin from the hyperthermophilic archaeon Pyrococcus furiosus (RdPf) and one from the mesophilic organism Desulfovibrio vulgaris (RdDv). The two proteins are simulated at four temperatures: 300 K, 373 K, 473 K (two sets), and 500 K; the various simulations extended from 200 ps to 1,020 ps. At room temperature, the two proteins are stable, remain close to the crystal structure, and exhibit similar dynamic behavior; the RMS residue fluctuations are slightly smaller in the hyperthermophilic protein. An analysis of the average energy contributions in the two proteins is made; the results suggest that the intraprotein energy stabilizes RdPf relative to RdDv. At 373 K, the mesophilic protein unfolds rapidly (it begins to unfold at 300 ps), whereas the hyperthermophilic does not unfold over the simulation of 600 ps. This is in accord with the expected stability of the two proteins. At 473 K, where both proteins are expected to be unstable, unfolding behavior is observed within 200 ps and the mesophilic protein unfolds faster than the hyperthermophilic one. At 500 K, both proteins unfold; the hyperthermophilic protein does so faster than the mesophilic protein. The unfolding behavior for the two proteins is found to be very similar. Although the exact order of events differs from one trajectory to another, both proteins unfold first by opening of the loop region to expose the hydrophobic core. This is followed by unzipping of the beta-sheet. The results obtained in the simulation are discussed in terms of the factors involved in flexibility and thermostability.

Lazaridis, T.; Lee, I.; Karplus, M.

1997-01-01

304

Mesophilic anaerobic treatment of sludge from saline fish farm effluents with biogas production  

Microsoft Academic Search

The mesophilic anaerobic treatment of sludge from saline fish farm effluents (total solids (TS): 8.2–10.2 wt%, chemical oxygen demand (COD): 60–74 g\\/l, sodium (Na): 10–10.5 g\\/l) was carried out in continuously stirred tank reactors (CSTRs) at 35 °C. COD stabilization between 36% and 55% and methane yields between 0.114 and 0.184 l\\/g COD added were achieved. However, the process was

Ruth Gebauer

2004-01-01

305

Isolation and Characterization of Methanobacterium espanolae sp. nov. , a Mesophilic, Moderately Acidiphilic Methanogen?  

Microsoft Academic Search

Bacterial strain GnT (T = type strain), a nonmotile, nonsporeforming, mesophilic, methanogenic bacterium, was isolated from the primary sludge obtained from the waste treatment facility of a major kraft pulp mill in Canada. Single cells were 6.0 by 0.8 pm and stained gram positive. Growth and methane production occurred only with H,-CO, as the substrate. Acetate, formate, propionate, butyrate, pyruvate,

G. B. PATEL; G. D. SPROTT; J. E. FEIN

306

Strategies for changing temperature from mesophilic to thermophilic conditions in anaerobic CSTR reactors treating sewage sludge  

Microsoft Academic Search

Thermophilic anaerobic digestion presents an advantageous way for stabilization of sludge from wastewater treatment plants. Two different strategies for changing operational process temperature from mesophilic (37°C) to thermophilic (55°C) were tested using two continuous flow stirred tank reactors operated at constant organic loading rate of 1.38g VS\\/l reactor\\/day and hydraulic retention time of 20 days. In reactor A, the temperature

A. Boušková; M. Dohányos; J. E. Schmidt; I. Angelidaki

2005-01-01

307

Comparative study of laboratory-scale thermophilic and mesophilic activated sludge processes  

Microsoft Academic Search

Laboratory-scale mesophilic (20–35°C) and thermophilic (55°C) activated sludge processes (ASPs) treating diluted molasses wastewater were compared in effluent quality, removal of different COD fractions, sludge yield, floc size, and sludge settleability. The effect of polyaluminium chloride (PAC) with high cationic charge on sludge settleability and effluent quality was also studied. In the ASPs, the hydraulic retention time was 12h in

J. Suvilampi; A. Lehtomäki; J. Rintala

2005-01-01

308

Effect of chitosan on UASB treating POME during a transition from mesophilic to thermophilic conditions  

Microsoft Academic Search

The effects of chitosan addition on treatment of palm oil mill effluent were investigated using two lab-scale upflow anaerobic sludge bed (UASB) reactors: (1) with chitosan addition at the dosage of 2mg chitosan per g volatile suspended solids on the first day of the operation (R1), (2) without chitosan addition (the control, R2). The reactors were inoculated with mesophilic anaerobic

Maneerat Khemkhao; Boonyarit Nuntakumjorn; Somkiet Techkarnjanaruk; Chantaraporn Phalakornkule

2011-01-01

309

A study of two-stage anaerobic digestion of solid potato waste using reactors under mesophilic and thermophilic conditions.  

PubMed

A two-stage anaerobic digestion process operated under mesophilic and thermophilic conditions was investigated for the treatment of solid potato waste to determine optimal methane yield, efficiency of operation and process stability. A solid-bed reactor was used for hydrolysis/acidification stage while an upflow anaerobic sludge blanket (UASB) reactor was used in the second stage, for methanogenesis. Three sets of conditions were investigated: (1) mesophilic + mesophilic, (II) mesophilic + thermophilic and (III) thermophilic + thermophilic in the hydrolysis/acidification and methanogenesis reactors, respectively. The methane yield was higher under mesophilic conditions (0.49 l CH4 g COD(-1)degraded) than thermophilic conditions (0.41 l CH4 g COD(-1)degraded) with reference to the methanogenic reactors. (COD)--chemical oxygen demand. However, the digestion period was shorter in systems II and III than in system I. Also, in system III the UASB reactor (thermophilic conditions) could handle a higher organic loading rate (OLR) (36 g COD 1(-1)d(-1)) than in system I (11 g COD 1(-1)d(-1)) (mesophilic conditions) with stable operation. Higher OLRs in the methanogenic reactors resulted in reactor failure due to increasing total volatile fatty acid levels. In all systems, the concentration of propionate was one of the highest, higher than acetic acid, among the volatile fatty acids in the effluent. The results show the feasibility of using a two-stage system to treat solid potato waste under both mesophilic and thermophilic conditions. If the aim is to treat solid potato waste completely within a short period of time thermophilic conditions are to be preferred, but to obtain higher methane yield mesophilic conditions are preferable and therefore there is a need to balance methane yield and complete digestion period when dealing with large quantities of solid potato waste. PMID:18290530

Parawira, W; Murto, M; Read, J S; Mattiasson, B

2007-11-01

310

In VivoCharacteristics and Localisation of Carotenoid Pigments in Psychrotrophic and Mesophilic Micrococcus roseusUsing Photoacoustic Spectroscopy  

Microsoft Academic Search

Photoacoustic spectra of cells ofM.roseuswere recorded to study thein vivocharacteristics and localisation of the carotenoid pigments in these cells. The PA spectra indicated that both the psychrotrophic and mesophilic strains had similar chromophores. Theciscarotenoids were prominent in the psychrotrophicM.roseuswhereas shorter polyenes were more prominent in mesophilicM.roseus.Further, depth profiling photoacoustic studies revealed that in both the strains ofM.roseusthe bulk of the

M. V. Jagannadham; K. Narayanan; Ch. Mohan Rao; S. Shivaji

1996-01-01

311

Comparative Evaluation of Bio-Hydrogen Production From Cheese Whey Wastewater Under Thermophilic and Mesophilic Anaerobic Conditions  

Microsoft Academic Search

Hydrogen production from cheese whey wastewater via dark fermentation was conducted using mixed culture under mesophilic (36°C ± 1) and thermophilic (55°C ± 1) conditions, respectively. The hydrogen yields and specific hydrogen production rates were found as follows: mesophilic: 9.2 mmol H2 \\/g COD (chemical oxygen demand) and 5.1 mL H2 \\/g VSS h; thermophilic: 8.1 mmol H2 \\/ g

N. Azbar; F. T. Dokgöz; T. Keskin; R. Eltem; K. S. Korkmaz; Y. Gezgin; Z. Akbal; S. Öncel; M. C. Dalay; Ç. Gönen; F. Tutuk

2009-01-01

312

Comparison of the treatment of a synthetic meat waste by mesophilic and thermophilic anaerobic fluidized bed reactors  

Microsoft Academic Search

Thermophilic anaerobic fluidised bed reactors (AFBRs) were shown to achieve inferior COD removal efficiencies in comparison to mesophilic AFBRs treating a synthetic meat waste. Organic removal efficiencies of 45.6–83.7% were observed for mesophilic reactors over a range of COD loadings between 0.5 ? 32 kg m d, while removal efficiencies of the thermophilic reactors were between 33.1–62% over the same

Thomasine Rudd; Stephen J. Hicks; John N. Lester

1985-01-01

313

Performance and energy economics of mesophilic and thermophilic digestion in anaerobic hybrid reactor treating coal wastewater.  

PubMed

Two anaerobic hybrid AHRs (AHR), mesophilic (35 °C) and thermophilic (55 °C) were operated with coal wastewater at different hydraulic retention times (HRT) ranging from 3-0.5 to 3.12-0.6d with organic loading rates (OLR) of 1.12-6.72 g L(-1) d(-1). Synthetic coal wastewater with an average chemical oxygen demand (COD) of 2240 mg L(-1) and phenolics concentration of 752 mg L(-1) was used as substrate. At each HRT, the thermophilic AHR gave a better performance, measured in terms of phenolics/COD removal and gas production. The specific methane yield was also higher for thermophilic AHR at each HRT compared to mesophilic one. The volatile fatty acid concentration in the effluent increased with the lowering of HRT. The Stover-Kincannon model was applicable at both temperatures and showed higher substrate utilization in thermophilic AHR. Energy economic study of the AHRs revealed that 11,938 MJ d(-1) more energy can be generated using thermophilic AHR than mesophilic. PMID:23138053

Ramakrishnan, Anushuya; Surampalli, Rao Y

2012-09-29

314

Aerobic degradation of aromatic compounds.  

PubMed

Our view on the bacterial responses to the aerobic degradation of aromatic compounds has been enriched considerably by the current omic methodologies and systems biology approaches, revealing the participation of intricate metabolic and regulatory networks. New enzymes, transporters, and specific/global regulatory systems have been recently characterized, and reveal that the widespread biodegradation capabilities extend to unexpected substrates such as lignin. A completely different biochemical strategy based on the formation of aryl-CoA epoxide intermediates has been unraveled for aerobic hybrid pathways, such as those involved in benzoate and phenylacetate degradation. Aromatic degradation pathways are also an important source of metabolic exchange factors and, therefore, they play a previously unrecognized biological role in cell-to-cell communication. Beyond the native bacterial biodegradation capabilities, pathway evolution as well as computational and synthetic biology approaches are emerging as powerful tools to design novel strain-specific pathways for degradation of xenobiotic compounds. PMID:23122741

Díaz, Eduardo; Jiménez, José Ignacio; Nogales, Juan

2012-11-01

315

Aerobic respiration in the Archaean?  

Microsoft Academic Search

THE Earth's atmosphere during the Archaean era (3,800-2,500 Myr ago) is generally thought to have been anoxic, with the partial pressure of atmospheric oxygen about 10-12 times the present value1. In the absence of aerobic consumption of oxygen produced by photosynthesis in the ocean, the major sink for this oxygen would have been oxidation of dissolved Fe(II). Atmospheric oxygen would

Kenneth M. Towe

1990-01-01

316

Anaerobic and aerobic degradation of pyridine by a newly isolated denitrifying bacterium.  

PubMed Central

New denitrifying bacteria that could degrade pyridine under both aerobic and anaerobic conditions were isolated from industrial wastewater. The successful enrichment and isolation of these strains required selenite as a trace element. These isolates appeared to be closely related to Azoarcus species according to the results of 16S rRNA sequence analysis. An isolated strain, pF6, metabolized pyridine through the same pathway under both aerobic and anaerobic conditions. Since pyridine induced NAD-linked glutarate-dialdehyde dehydrogenase and isocitratase activities, it is likely that the mechanism of pyridine degradation in strain pF6 involves N-C-2 ring cleavage. Strain pF6 could degrade pyridine in the presence of nitrate, nitrite, and nitrous oxide as electron acceptors. In a batch culture with 6 mM nitrate, degradation of pyridine and denitrification were not sensitively affected by the redox potential, which gradually decreased from 150 to -200 mV. In a batch culture with the nitrate concentration higher than 6 mM, nitrite transiently accumulated during denitrification significantly inhibited cell growth and pyridine degradation. Growth yield on pyridine decreased slightly under denitrifying conditions from that under aerobic conditions. Furthermore, when the pyridine concentration used was above 12 mM, the specific growth rate under denitrifying conditions was higher than that under aerobic conditions. Considering these characteristics, a newly isolated denitrifying bacterium, strain pF6, has advantages over strictly aerobic bacteria in field applications.

Rhee, S K; Lee, G M; Yoon, J H; Park, Y H; Bae, H S; Lee, S T

1997-01-01

317

Physiological and phylogenetic diversity of thermophilic spore-forming hydrocarbon-oxidizing bacteria from oil fields  

Microsoft Academic Search

The distribution and population density of aerobic hydrocarbon-oxidizing bacteria in the high-temperature oil fields of Western\\u000a Siberia, Kazakhstan, and China were studied. Seven strains of aerobic thermophilic spore-forming bacteria were isolated from\\u000a the oil fields and studied by microbiological and molecular biological methods. Based on the 16S rRNA gene sequences, phenotypic\\u000a characteristics, and the results of DNA-DNA hybridization, the taxonomic

T. N. Nazina; T. P. Tourova; A. B. Poltaraus; E. V. Novikova; A. E. Ivanova; A. A. Grigoryan; A. M. Lysenko; S. S. Belyaev

2000-01-01

318

Development of microorganisms in the chernozem under aerobic and anaerobic conditions  

NASA Astrophysics Data System (ADS)

A microbial succession was studied under aerobic and anaerobic conditions by means of experiments with microcosms in different horizons of a chernozem. It was revealed that, under aerobic conditions, all the microorganisms grow irrespective of the soil horizon; fungi and bacteria grow at the first succession stages, and actinomycetes grow at the last stages. It was shown that, in the case of a simulated anaerobiosis commonly used to study anaerobic populations of bacteria, the mycelium of micromycetes grows in the upper part of the chernozem’s A horizon. Under anaerobic conditions, the peak of the mycelium development is shifted from the 3rd to 7th days (typical for aerobic conditions) to the 7th to 15th days of incubation. The level of mycelium length’s stabilization under aerobic and anaerobic conditions also differs: it is higher or lower than the initial one, respectively. Under anaerobic conditions, the growth of fungal mycelium, bacteria, and actinomycetes in the lower part of the A horizon and in the B horizon is extremely weak. There was not any observed growth of actinomycetes in all the chernozem’s horizons under anaerobic conditions.

Polyanskaya, L. M.; Gorbacheva, M. A.; Milanovskii, E. Yu.; Zvyagintsev, D. G.

2010-03-01

319

Isolation, Characterization, and Ecology of Cold-Active, Chemolithotrophic, Sulfur-Oxidizing Bacteria from Perennially Ice-Covered Lake Fryxell, Antarctica  

Microsoft Academic Search

Novel strains of obligately chemolithoautotrophic, sulfur-oxidizing bacteria have been isolated from various depths of Lake Fryxell, Antarctica. Physiological, morphological, and phylogenetic analyses showed these strains to be related to mesophilic Thiobacillus species, such as T. thioparus. However, the psychrotolerant Antarctic isolates showed an adaptation to cold temperatures and thus should be active in the nearly freezing waters of the lake.

W. Matthew Sattley; Michael T. Madigan

2006-01-01

320

Anaerobic degradation and carbon isotopic fractionation of alkylbenzenes in crude oil by sulphate-reducing bacteria  

Microsoft Academic Search

A mesophilic enrichment culture of sulphate-reducing bacteria isolated from the water phase of a North Sea oil tank using oil from the same tank as sole source of carbon and energy specifically depletes certain C1–C5 alkylbenzenes in crude oil during growth. The enrichment culture grows on oils of different origin and composition resulting in similar patterns of alkylbenzene depletion. Two

Heinz Wilkes; Chris Boreham; Gerda Harms; Karsten Zengler; Ralf Rabus

2000-01-01

321

Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.  

PubMed

Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if "endogenous" bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain). The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP) analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil. PMID:23028421

Gong, Xiao-Cui; Liu, Ze-Shen; Guo, Peng; Chi, Chang-Qiao; Chen, Jian; Wang, Xing-Biao; Tang, Yue-Qin; Wu, Xiao-Lei; Liu, Chun-Zhong

2012-09-17

322

Isolation and characterization of quinoline-degrading bacteria from subsurface sediments.  

PubMed Central

Two gram-negative, motile bacteria isolated from deep subsurface sediments mineralized the nitrogen-containing polyaromatic hydrocarbon quinoline under aerobic conditions and transformed quinoline to soluble intermediates under anaerobic conditions. Many aromatic compounds were also able to serve as the sole source of carbon and energy under aerobic conditions. Rapid aerobic mineralization of quinoline at concentrations as low as 0.002 microgram ml-1 indicates that these organisms possess a high-affinity uptake and utilization system, which may reflect the oligotrophic nature of deep subsurface environments. Both bacteria harbored four plasmids of identical size, ranging from 50 to 440 kilobases. Images

Brockman, F J; Denovan, B A; Hicks, R J; Fredrickson, J K

1989-01-01

323

Lower limb loading in step aerobic dance.  

PubMed

Participation in aerobic dance is associated with a number of lower extremity injuries, and abnormal joint loading seems to be a factor in these. However, information on joint loading is limited. The purpose of this study was to investigate the kinetics of the lower extremity in step aerobic dance and to compare the differences of high-impact and low-impact step aerobic dance in 4 aerobic movements (mambo, kick, L step and leg curl). 18 subjects were recruited for this study. High-impact aerobic dance requires a significantly greater range of motion, joint force and joint moment than low-impact step aerobic dance. The peak joint forces and moments in high-impact step aerobic dance were found to be 1.4 times higher than in low-impact step aerobic dance. Understanding the nature of joint loading may help choreographers develop dance combinations that are less injury-prone. Furthermore, increased knowledge about joint loading may be helpful in lowering the risk of injuries in aerobic dance instructors and students. PMID:22706950

Wu, H-W; Hsieh, H-M; Chang, Y-W; Wang, L-H

2012-06-15

324

Regional aerobic glycolysis in the human brain  

PubMed Central

Aerobic glycolysis is defined as glucose utilization in excess of that used for oxidative phosphorylation despite sufficient oxygen to completely metabolize glucose to carbon dioxide and water. Aerobic glycolysis is present in the normal human brain at rest and increases locally during increased neuronal activity; yet its many biological functions have received scant attention because of a prevailing energy-centric focus on the role of glucose as substrate for oxidative phosphorylation. As an initial step in redressing this neglect, we measured the regional distribution of aerobic glycolysis with positron emission tomography in 33 neurologically normal young adults at rest. We show that the distribution of aerobic glycolysis in the brain is differentially present in previously well-described functional areas. In particular, aerobic glycolysis is significantly elevated in medial and lateral parietal and prefrontal cortices. In contrast, the cerebellum and medial temporal lobes have levels of aerobic glycolysis significantly below the brain mean. The levels of aerobic glycolysis are not strictly related to the levels of brain energy metabolism. For example, sensory cortices exhibit high metabolic rates for glucose and oxygen consumption but low rates of aerobic glycolysis. These striking regional variations in aerobic glycolysis in the normal human brain provide an opportunity to explore how brain systems differentially use the diverse cell biology of glucose in support of their functional specializations in health and disease.

Vaishnavi, S. Neil; Vlassenko, Andrei G.; Rundle, Melissa M.; Snyder, Abraham Z.; Mintun, Mark A.; Raichle, Marcus E.

2010-01-01

325

Swimming bacteria power microscopic gears.  

SciTech Connect

Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be 'rectified' under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms.

Sokolov, A.; Apodaca, M. M.; Grzybowski, B. A.; Aranson, I. S.; Materials Science Division; Princeton Univ.; Northwestern Univ.

2010-01-19

326

Swimming bacteria power microscopic gears  

NASA Astrophysics Data System (ADS)

While the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in systems at equilibrium, under non-equlibrium conditions their motions can be ``rectified'', for example, in the presence of asymmetric geometrical obstacles. We describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears' angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganism.

Sokolov, Andrey; Aronson, Igor; Apodaca, Mario; Grzybowski, Bartosz

2010-03-01

327

Swimming bacteria power microscopic gears  

SciTech Connect

Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be “rectified” under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears’ angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms.

Sokolov, Andrey; Apodaca, Mario M.; Grzybowski, Bartosz A.; Aranson, Igor S.

2010-01-01

328

Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1  

NASA Astrophysics Data System (ADS)

Magnetotactic bacteria have become a hot spot of research in microbiology attracting intensive interest of researchers in multiple disciplinary fields. However, the studies were limited in few fastidious bacteria. The objective of this study aims at isolating new marine magnetic bacteria and better comprehension of magnetotactic bacteria. In this study, an aerobic magnetotactic bacterium YSC-1 was isolated from sediments in the Yellow Sea Cold Water Mass (YSCWM). In TEM, magnetic cells have one or several circular magnetosomes in diameter of 100nm, and consist of Fe and Co shown on energy dispersive X-ray spectrum. The biological and physiological characteristics of this bacterium were also described. The colour of YSC-1 colony is white in small rod. The gram stain is negative. Results showed that Strain YSC-1 differs from microaerophile magnetotactic bacteria MS-1 and WD-1 in biology.

Gao, Jun; Pan, Hongmiao; Yue, Haidong; Song, Tao; Zhao, Yong; Chen, Guanjun; Wu, Longfei; Xiao, Tian

2006-12-01

329

BIOMECHANICAL ANALYSIS OF HIGH-LOW IMPACT AEROBIC DANCE AND STEP AEROBICS  

Microsoft Academic Search

The purpose of this study was to compare the kinematics and kinetics both in high-Iow impact aerobic dance and step aerobics. Six female subjects performed front knee lift movements under high-Iow impact aerobics and two-step heights (10, 20 cm) in step aerobics. One Peak high-speed camera (120 Hz) and one Kistler force plate (600 Hz) were synchronized to collect the

Shi-Yi Wang; Chenfu Huang; Chung Hsien Yang

2002-01-01

330

Trichloroethylene biodegradation by mesophilic and psychrophilic ammonia oxidizers and methanotrophs in groundwater microcosms.  

PubMed Central

This study investigated the efficiency of methane and ammonium for stimulating trichloroethylene (TCE) biodegradation in groundwater microcosms (flasks and batch exchange columns) at a psychrophilic temperature (12 degrees C) typical of shallow aquifers in the northern United States or a mesophilic temperature (24 degrees C) representative of most laboratory experiments. After 140 days, TCE biodegradation rates by ammonia oxidizers and methanotrophs in mesophilic flask microcosms were similar (8 to 10 nmol day-1), but [14C]TCE mineralization (biodegradation to 14CO2) by ammonia oxidizers was significantly greater than that by methanotrophs (63 versus 53%). Under psychrophilic conditions, [14C]TCE mineralization in flask systems by ammonia oxidizers and methanotrophs was reduced to 12 and 5%, respectively. In mesophilic batch exchange columns, average TCE biodegradation rates for methanotrophs (900 nmol liter-1 day-1) were not significantly different from those of ammonia oxidizers (775 nmol liter-1 day-1). Psychrophilic TCE biodegradation rates in the columns were similar with both biostimulants and averaged 145 nmol liter-1 day-1. Methanotroph biostimulation was most adversely affected by low temperatures. At 12 degrees C, the biodegradation efficiencies (TCE degradation normalized to microbial activity) of methanotrophs and ammonia oxidizers decreased by factors of 2.6 and 1.6, respectively, relative to their biodegradation efficiencies at 24 degrees C. Collectively, these experiments demonstrated that in situ bioremediation of TCE is feasible at the psychrophilic temperatures common in surficial aquifers in the northern United States and that for such applications biostimulation of ammonia oxidizers could be more effective than has been previously reported.

Moran, B N; Hickey, W J

1997-01-01

331

How “Healthful” Are Aerobics Classes? Exploring the Health and Wellness Messages in Aerobics Classes for Women  

Microsoft Academic Search

The purpose of this study was to explore the health messages communicated by aerobics instructors in aerobics classes for women. A theoretical framework influenced by adult learning theory and feminist pedagogy was used in this qualitative study. Over a 3-month period, the practices of five aerobics instructors working at one nonprofit fitness center and one wellness facility were explored. The

Michelle Lee D’abundo

2007-01-01

332

Local entropy difference upon a substrate binding of a psychrophilic ?-amylase and a mesophilic homologue  

NASA Astrophysics Data System (ADS)

Psychrophilic ?-amylase from the antarctic bacterium pseudoalteromonashaloplanktis (AHA) and its mesophilic homologue, porcine pancreatic ?-amylase (PPA) are theoretically investigated with molecular dynamics (MD) simulations. We carried out 240-ns MD simulations for four systems, AHA and PPA with/without the bound substrate, and examined protein conformational entropy changes upon the substrate binding. We developed an analysis that decomposes the entropy changes into contributions of individual amino acids, and successfully identified protein regions responsible for the entropy changes. The results provide a molecular insight into the structural flexibilities of those enzymes related to the temperature dependences of the enzymatic activity.

Kosugi, Takahiro; Hayashi, Shigehiko

2011-01-01

333

Scouring Potential of Mesophile Acidic Proteases of Pseudomonas aeruginosa for Grey Cotton Fabrics  

NASA Astrophysics Data System (ADS)

Mesophile, acidic proteases were produced using the microbial source, Pseudomonas aeruginosa, with wider thermal tolerances. Process conditions of scouring treatment were optimized using Taguchi method for optimum temperature, time, pH and concentration of protease. Treatment with the protease lower weight loss values compared to the alkali scouring, however, significant improvement in the absorbency compared to the grey samples was observed. Large amounts of pectin left out in the samples resulted in higher extractable impurities, substantiated by the FTIR results. Relatively, lower reduction in the tear strengths was observed in both warp and weft directions after protease treatment of the cotton fabrics.

Saravanan, D.

2013-04-01

334

Metal recovery from mine tailings using bacteria  

Microsoft Academic Search

Zinc metal and zinc sulfide were recovered by oxidative dissolution using Thiobacillus ferrooxidans, which is aerobic, autotrophic, and acidophilic bacteria. Thiobacillus ferrooxidans derive energy from oxidation of ferrous iron and elemental sulfur using molecular oxygen as an electron acceptor. From the 10,000 mg\\/L of initial zinc concentration, 97% solubilization of zinc metal was obtained from coarse FeSâ due to microbial

S KANG

1994-01-01

335

Sediment bacteria in the deep Norwegian Sea  

Microsoft Academic Search

During a joint French-Swedish expedition (NORBI) in July-August, 1975, in the deep Norwegian Sea, the density of aerobic, heterotrophic sediment bacteria was determined by viable counts at 9 stations. The numbers rarely exceeded 103 ml-1 wet sediment. ATP measurements, with a limit of detectability of 5 ng ml-1 wet sediment, gave constantly negative results. One third of the strains isolated

B. Norkrans; B. O. Stehn

1978-01-01

336

Soccer specific aerobic endurance training  

PubMed Central

Background: In professional soccer, a significant amount of training time is used to improve players' aerobic capacity. However, it is not known whether soccer specific training fulfils the criterion of effective endurance training to improve maximal oxygen uptake, namely an exercise intensity of 90–95% of maximal heart rate in periods of three to eight minutes. Objective: To determine whether ball dribbling and small group play are appropriate activities for interval training, and whether heart rate in soccer specific training is a valid measure of actual work intensity. Methods: Six well trained first division soccer players took part in the study. To test whether soccer specific training was effective interval training, players ran in a specially designed dribbling track, as well as participating in small group play (five a side). Laboratory tests were carried out to establish the relation between heart rate and oxygen uptake while running on a treadmill. Corresponding measurements were made on the soccer field using a portable system for measuring oxygen uptake. Results: Exercise intensity during small group play was 91.3% of maximal heart rate or 84.5% of maximal oxygen uptake. Corresponding values using a dribbling track were 93.5% and 91.7%. No higher heart rate was observed during soccer training. Conclusions: Soccer specific exercise using ball dribbling or small group play may be performed as aerobic interval training. Heart rate monitoring during soccer specific exercise is a valid indicator of actual exercise intensity.

Hoff, J; Wisloff, U; Engen, L; Kemi, O; Helgerud, J

2002-01-01

337

Aerobic and anaerobic bioprocessing of activated sludge: floc disintegration by enzymes.  

PubMed

Hydrolytic enzymes such as glucosidases, lipases, and proteases have an imperative function at the hydrolysis stage of complex organic structures in the degradation of biodegradable particulate organic matter. As a key factor, extracellular polymeric substances (EPS) control the extracellular hydrolytic enzymes in this degradation mechanism. A flocculated matrix of EPS bridging with bacteria holds back the dewaterability properties of the bioprocessed sludges. Disruption of the flocculated matrix leads to improved solubilization of sludge solids by attacking the hydrolytic enzymes to polymeric substances forming enzyme-substrate complexes. To determine the floc disintegration mechanisms by enzymes during aerobic and anaerobic bioprocessing of sludges, experimental data obtained from three aerobic digesters and three anaerobic digesters were evaluated. As part of a broader project examining the overall fate and effects of hydrolytic enzymes in biological sludge stabilization, this paper compares the performances of aerobic and anaerobic reactors used in this study and reports significant improvements in enzymatic treatment of activated sludge. PMID:18821239

Ayol, Azize; Filibeli, Ayse; Sir, Diclehan; Kuzyaka, Ersan

2008-11-01

338

Acidophilic, heterotrophic bacteria of acidic mine waters  

SciTech Connect

Obligately acidophilic, heterotrophic bacteria were isolated both from enrichment cultures developed with acidic mine water and from natural mine drainage. The bacteria were grouped by the ability to utilize a number of organic acids as sole carbon sources. None of the strains were capable of chemolithotrophic growth on inorganic reduced iron and sulfur compounds. All bacteria were rod shaped, gram negative, nonencapsulated, motile, capable of growth at pH 2.6 but not at pH 6.0, catalase and oxidase positive, strictly aerobic, and capable of growth on citric acid. The bacteria were cultivatable on solid nutrient media only if agarose was employed as the hardening agent. Bacterial densities in natural mine waters ranged from approximately 20 to 250 cells per ml, depending upon source and culture medium.

Wichlacz, P.L.; Unz, R.F.

1981-05-01

339

Aerobic Exercise: Top 10 Reasons to Get Physical  

MedlinePLUS

... only. Aerobic exercise: Top 10 reasons to get physical By Mayo Clinic staff Original Article: http://www. ... up Aerobic exercise: Top 10 reasons to get physical Regardless of age, weight or athletic ability, aerobic ...

340

Aerobic Fitness: What Are We Measuring?  

Microsoft Academic Search

Aerobic fitness depends upon the components of oxygen delivery and the oxidative mechanisms of the exercising muscle. Peak oxygen uptake is recognised as the best single criterion of aerobic fitness but it is strongly correlated with body size. Methods of controlling for body size are discussed and it is demonstrated how inappropriate use of ratio scaling has clouded our understanding

N. Armstrong; J. Welsman

2007-01-01

341

Pelotomaculum propionicicum sp. nov., an anaerobic, mesophilic, obligately syntrophic, propionate-oxidizing bacterium.  

PubMed

An anaerobic, mesophilic, syntrophic, propionate-oxidizing bacterium, strain MGP(T), was isolated as a defined co-culture with Methanospirillum hungatei from the methanogenic sludge of a mesophilic upflow anaerobic sludge blanket (UASB) reactor. The strain grew in the presence of propionate, but only in co-culture with methanogens, suggesting that it is an obligately syntrophic bacterium. The optimum temperature for growth was 37 degrees C, and the optimum pH was between 6.5 and 7.2. Based on comparative 16S rRNA gene sequence analysis, strain MGP(T) was affiliated with subcluster Ih of 'Desulfotomaculum cluster I', in which it was found to be moderately related to known species of the genera Pelotomaculum and Cryptanaerobacter. Similar to known species of the genus Pelotomaculum, strain MGP(T) could degrade propionate in syntrophy, but had no ability to reduce sulfate, sulfite and thiosulfate. Further phenotypic and genetic studies supported the affiliation of the strain as a novel species in this genus, for which the name Pelotomaculum propionicicum sp. nov. is proposed. The type strain is MGP(T) (=DSM 15578(T)=JCM 11929(T)). The strain has been deposited in the DSM and JCM culture collections as a defined co-culture with Methanospirillum hungatei. PMID:17625181

Imachi, Hiroyuki; Sakai, Sanae; Ohashi, Akiyoshi; Harada, Hideki; Hanada, Satoshi; Kamagata, Yoichi; Sekiguchi, Yuji

2007-07-01

342

Diversity of a mesophilic lignocellulolytic microbial consortium which is useful for enhancement of biogas production.  

PubMed

A mesophilic lignocellulolytic microbial consortium BYND-5, established by successive subcultivation, was applied to enhance the biogas production. The degradation efficiency of BYND-5 for rice straw was more than 49.0 ± 1.8% after 7 days of cultivation at 30°C. Various organic compounds, including acetic acid, propionic acid, butyric acid and glycerin were detected during biodegradation. The diversity analysis of BYND-5 was conducted by ARDRA (Amplified ribosomal DNA restriction analysis) of the 16S rDNA clone library. Results indicated that bacterial groups represented in the clone library were the Firmicutes (5.96%), the Bacteroidetes (40.0%), Deferribacteres (8.94%), Proteobacteria (16.17%), Lentisphaerae (2.13%), Fibrobacteraceae (1.7%), and uncultured bacterium (25.1%). Additionally, the enhancement of biogas yield and methane content was directly related to the pretreatment with BYND-5. The microbial community identified herein is potential candidate consortium for the degradation of waste lignocellulose and enhancement of biogas production under the mesophilic temperature conditions. PMID:22365718

Yan, Lei; Gao, Yamei; Wang, Yanjie; Liu, Quan; Sun, Zhiyuan; Fu, Borui; Wen, Xue; Cui, Zongjun; Wang, Weidong

2012-02-08

343

Temperature Adaptation at Homologous Sites in Proteins from Nine Thermophile-Mesophile Species Pairs  

PubMed Central

Whether particular amino acids are favored by selection at high temperatures over others has long been an open question in protein evolution. One way to approach this question is to compare homologous sites in proteins from one thermophile and a closely related mesophile; asymmetrical substitution patterns have been taken as evidence for selection favoring certain amino acids over others. However, most pairs of prokaryotic species that differ in optimum temperature also differ in genome-wide GC content, and amino acid content is known to be associated with GC content. Here, I compare homologous sites in nine thermophilic prokaryotes and their mesophilic relatives, all with complete published genome sequences. After adjusting for the effects of differing GC content with logistic regression, 139 of the 190 pairs of amino acids show significant substitutional asymmetry, evidence of widespread adaptive amino acid substitution. The patterns are fairly consistent across the nine pairs of species (after taking the effects of differing GC content into account), suggesting that much of the asymmetry results from adaptation to temperature. Some amino acids in some species pairs deviate from the overall pattern in ways indicating that adaptation to other environmental or physiological differences between the species may also play a role. The property that is best correlated with the patterns of substitutional asymmetry is transfer free energy, a measure of hydrophobicity, with more hydrophobic amino acids favored at higher temperatures. The correlation of asymmetry and hydrophobicity is fairly weak, suggesting that other properties may also be important.

McDonald, John H.

2010-01-01

344

The utilization of RAPD-PCR for identifying thermophilic and mesophilic Bacillus species.  

PubMed

A random amplified polymorphic DNA fingerprinting assay has been optimized that is able to discriminate between numerous thermophilic and mesophilic bacillus species and strains. Included in the analyses are thermophilic (able to grow at 55 degrees C) strains of Bacillus stearothermophilus, B. kaustophilus, B. coagulans, B. sphaericus, B. thermodenitrificans, B. thermocatenulatus, B. thermoleovorans, B. licheniformis, B. brevis, B. thermoglucosidasius, B. caldolyticus, B. caldotenax, B. caldovelox, B. thermocloacae and B. smithii. Mesophilic strains of B. pumilus, B. subtilis, B. megaterium, B. circulans, B. cereus and B. mycoides can also be used for fingerprinting with the assay. Increasing the concentration of primer from 0.2 to 2.0 microM is shown to have a significant effect on increasing the number of amplification products that can be used for the discrimination or identification of individual strains or species. It is suggested that this may be a general way of improving the resolution of a RAPD protocol. The optimized conditions have been used successfully to trace B. stearothermophilus, B. licheniformis and other bacillus species and strains in an industrial setting. PMID:9037767

Ronimus, R S; Parker, L E; Morgan, H W

1997-02-01

345

Mesophilic and thermophilic anaerobic biodegradability of water hyacinth pre-treated at 80 degrees C.  

PubMed

Water hyacinth (Eichornia crassipes) is a fast growing aquatic plant which causes environmental problems in continental water bodies. Harvesting and handling this plant becomes an issue, and focus has been put on the research of treatment alternatives. Amongst others, energy production through biomethanation has been proposed. The aim of this study was to assess the anaerobic biodegradability of water hyacinth under mesophilic and thermophilic conditions. The effect of a thermal sludge pre-treatment at 80 degrees C was also evaluated. To this end, anaerobic biodegradability tests were carried out at 35 degrees C and 55 degrees C, with raw and pre-treated water hyacinth. According to the results, the thermal pre-treatment enhanced the solubilisation of water hyacinth (i.e. increase in the soluble to total chemical oxygen demand (COD)) from 4% to 12% after 30 min. However, no significant effect was observed on the methane yields (150-190 L CH(4)/kg volatile solids). Initial methane production rates for thermophilic treatments were two fold those of mesophilic ones (6-6.5L vs. 3-3.5 L CH(4)/kg COD x day). Thus, higher methane production rates might be expected from thermophilic reactors working at short retention times. The study of longer low temperature pre-treatments or pre-treatments at elevated temperatures coupled to thermophilic reactors should be considered in the future. PMID:19837577

Ferrer, Ivet; Palatsi, Jordi; Campos, Elena; Flotats, Xavier

2009-10-17

346

Comparative performance of mesophilic and thermophilic anaerobic digestion for high-solid sewage sludge.  

PubMed

In local cities, many small sewage and waste treatment facilities are operated independently. To encourage processing by anaerobic digestion at a centralized sewage treatment plant (STP), high-solid sewage sludge is helpful because it reduces the energy and cost required for transporting the sludge from other STPs. Mesophilic and thermophilic anaerobic digestion of sewage sludge at total solids concentrations (TS) of 7.5% and 10% were evaluated using laboratory-scale continuous reactors. Under the mesophilic condition, sewage sludge of 10% TS was successfully treated. Under the thermophilic condition, sewage sludge of 7.5% TS was not successfully treated when the total ammonia concentration was over 2000mgN/L. Batch experiments showed that it takes a few weeks for the methane fermentation activity to recover after being inhibited. The effectiveness of adding easily biodegradable organic matter was confirmed. These results show that high-solid sewage sludge is suitable for small facilities by controlling the operating conditions. PMID:24096284

Hidaka, Taira; Wang, Feng; Togari, Taketo; Uchida, Tsutomu; Suzuki, Yutaka

2013-09-17

347

Effect of sodium chloride on growth of heterotrophic marine bacteria  

Microsoft Academic Search

The effect of NaCl on the growth rates and yields of 31 gram-negative, heterotrophic, marine bacteria was determined. The strains used were representative of aerobic genera (Alteromonas, Pseudomonas, Alcaligenes, Bdellovibrio) as well as genera comprised of facultative anaerobes (Beneckea, Photobacterium). Two media were used-the first, a medium designed for the cultivation of marine bacteria and, the second, a medium used

John L. Reichelt; Paul Baumann

1974-01-01

348

Application of antimicrobial-producing lactic acid bacteria to control pathogens in ready-to-use vegetables.  

PubMed

Five psychrotrophic strains of lactic acid bacteria (Lactobacillus casei, Lact. plantarum and Pediococcus spp.) were isolated from 22 samples of commercial salads. These strains were shown to inhibit Aeromonas hydrophila, Listeria monocytogenes, Salmonella typhimurium and Staphylococcus aureus on MRS agar, in salads and in juice prepared from vegetable salads. Lactobacillus casei IMPCLC34 was most effective in reducing total mesophilic bacteria and the coliform group; Aer. hydrophila, Salm. typhimurium and Staph. aureus disappeared after 6 d of storage, while the counts for L. monocytogenes remained constant. The potential application of antimicrobial-producing lactic acid bacteria as biopreservatives of ready-to-use vegetables is suggested. PMID:8760320

Vescovo, M; Torriani, S; Orsi, C; Macchiarolo, F; Scolari, G

1996-08-01

349

In vivo characteristics and localisation of carotenoid pigments in psychrotrophic and mesophilic Micrococcus roseus using photoacoustic spectroscopy.  

PubMed

Photoacoustic spectra of cells of M. roseus were recorded to study the in vivo characteristics and localisation of the carotenoid pigments in these cells. The PA spectra indicated that both the psychrotrophic and mesophilic strains had similar chromophores. The cis carotenoids were prominent in the psychrotrophic M.roseus whereas shorter polyenes were more prominent in mesophilic M.roseus. Further, depth profiling photoacoustic studies revealed that in both the strains of M.roseus the bulk of the chromophore was associated with the cell membrane. PMID:8858129

Jagannadham, M V; Narayanan, K; Rao, C M; Shivaji, S

1996-10-01

350

Comparison of the Survival and Metabolic Activity of Psychrophilic and Mesophilic Yeasts Subjected to Freeze-Thaw Stress  

PubMed Central

A mesophilic yeast, Candida utilis, and a psychrophilic yeast, Leucosporidium stokesii, were subjected to freeze-thaw cycling over the range 25 to -60 C. Viability after freeze-thaw stress was directly correlated with the rate of cooling and the physiological age of the cultures. Rates of glucose fermentation and oxidation could be directly correlated with viability. The optimal cooling rate for both yeast strains was 4.5 to 6.5 C/min; however, their levels of survival obtained at this optimal cooling rate varied considerably. In addition, the psychrophile was less resistant to freeze-thaw stress than was the mesophile.

Meyer, Edward D.; Sinclair, Norval A.; Nagy, Bartholomew

1975-01-01

351

Unravelling the reasons for disproportion in the ratio of AOB and NOB in aerobic granular sludge.  

PubMed

In this study, we analysed the nitrifying microbial community (ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB)) within three different aerobic granular sludge treatment systems as well as within one flocculent sludge system. Granular samples were taken from one pilot plant run on municipal wastewater as well as from two lab-scale reactors. Fluorescent in situ hybridization (FISH) and quantitative PCR (qPCR) showed that Nitrobacter was the dominant NOB in acetate-fed aerobic granules. In the conventional system, both Nitrospira and Nitrobacter were present in similar amounts. Remarkably, the NOB/AOB ratio in aerobic granular sludge was elevated but not in the conventional treatment plant suggesting that the growth of Nitrobacter within aerobic granular sludge, in particular, was partly uncoupled from the lithotrophic nitrite supply from AOB. This was supported by activity measurements which showed an approximately threefold higher nitrite oxidizing capacity than ammonium oxidizing capacity. Based on these findings, two hypotheses were considered: either Nitrobacter grew mixotrophically by acetate-dependent dissimilatory nitrate reduction (ping-pong effect) or a nitrite oxidation/nitrate reduction loop (nitrite loop) occurred in which denitrifiers reduced nitrate to nitrite supplying additional nitrite for the NOB apart from the AOB. PMID:22573276

Winkler, Mari K H; Bassin, João P; Kleerebezem, Robbert; Sorokin, Dimitry Y; van Loosdrecht, Mark C M

2012-05-11

352

Degradation of Phthalic Acids by Denitrifying, Mixed Cultures of Bacteria  

PubMed Central

Mixed cultures of bacteria, enriched from aquatic sediments, grew anaerobically on all three isomers of phthalic acid. Each culture grew anaerobically on only one isomer and also grew aerobically on the same isomer. Pure cultures were isolated from the phthalic acid (o-phthalic acid) and isophthalic acid (m-phthalic acid) enrichments that grew aerobically on phthalic and isophthalic acids. Cell suspension experiments indicated that protocatechuate is an intermediate of aerobic catabolism. Pure cultures which grew aerobically on terephthalic acid (p-phthalic acid) could not be isolated from the enrichments, and neither could pure cultures that grew anaerobically on any of the isomers. Cell suspension experiments suggested that separate pathways exist for the aerobic and anaerobic oxidation of phthalic acids. Each enrichment culture used only one phthalic acid isomer under anaerobic conditions, but all isomers were simultaneously adapted for the anaerobic catabolism of benzoate. Cells grown anaerobically on a phthalic acid immediately attacked the isomer under anaerobic conditions, whereas there was a lag before aerobic breakdown occurred, and, for phthalic and terephthalic acids, chloramphenicol stopped aerobic adaptation but had no effect on anaerobic catabolism. This work suggests that phthalic acids are biodegradable in anaerobic environments.

Aftring, R. Paul; Chalker, Bruce E.; Taylor, Barrie F.

1981-01-01

353

A STUDY ON AEROBIC BACTERIAL FLORA DURING INCUBATION OF RAINBOW TROUT (Oncorhynchus mykiss, Walbaum 1792) EGGS IN HATCHERY  

Microsoft Academic Search

Aerobic bacterial flora in rainbow trout egg, Oncorhynchus mykiss, Walbaum 1792, and the hatchery water were analyzed. It was determined that the number of bacteria varied between 10 3 -10 4 cfu g -1 in disinfected eggs and 10 6 -10 7 cfu g -1 in undisinfected eggs. The total bacterial count was 5.7x 102 cfu ml-1 in the spring

Soner Altun

354

Comparative In Vitro Activities of GAR936 against Aerobic and Anaerobic Animal and Human Bite Wound Pathogens  

Microsoft Academic Search

GAR-936 is a new semisynthetic glycylcycline with a broad antibacterial spectrum, including tetracycline- resistant strains. The in vitro activities of GAR-936, minocycline, doxycycline, tetracycline, moxifloxacin, penicillin G, and erythromycin were determined by agar dilution methods against 268 aerobic and 148 anaerobic strains of bacteria (including Pasteurella, Eikenella, Moraxella, Bergeyella, Neisseria, EF-4, Bacteroides, Prevotella, Porphyromonas, Fusobacterium, Staphylococcus, Streptococcus, Enterococcus, Corynebacterium, Propi-

ELLIE J. C. GOLDSTEIN; DIANE M. CITRON; C. VRENI MERRIAM; YUMI WARREN; KERIN TYRRELL

2000-01-01

355

Metagenomics of hydrocarbon resource environments indicates aerobic taxa and genes to be unexpectedly common.  

PubMed

Oil in subsurface reservoirs is biodegraded by resident microbial communities. Water-mediated, anaerobic conversion of hydrocarbons to methane and CO2, catalyzed by syntrophic bacteria and methanogenic archaea, is thought to be one of the dominant processes. We compared 160 microbial community compositions in ten hydrocarbon resource environments (HREs) and sequenced twelve metagenomes to characterize their metabolic potential. Although anaerobic communities were common, cores from oil sands and coal beds had unexpectedly high proportions of aerobic hydrocarbon-degrading bacteria. Likewise, most metagenomes had high proportions of genes for enzymes involved in aerobic hydrocarbon metabolism. Hence, although HREs may have been strictly anaerobic and typically methanogenic for much of their history, this may not hold today for coal beds and for the Alberta oil sands, one of the largest remaining oil reservoirs in the world. This finding may influence strategies to recover energy or chemicals from these HREs by in situ microbial processes. PMID:23889694

An, Dongshan; Caffrey, Sean M; Soh, Jung; Agrawal, Akhil; Brown, Damon; Budwill, Karen; Dong, Xiaoli; Dunfield, Peter F; Foght, Julia; Gieg, Lisa M; Hallam, Steven J; Hanson, Niels W; He, Zhiguo; Jack, Thomas R; Klassen, Jonathan; Konwar, Kishori M; Kuatsjah, Eugene; Li, Carmen; Larter, Steve; Leopatra, Verlyn; Nesbø, Camilla L; Oldenburg, Thomas; Pagé, Antoine P; Ramos-Padron, Esther; Rochman, Fauziah F; Saidi-Mehrabad, Alireeza; Sensen, Christoph W; Sipahimalani, Payal; Song, Young C; Wilson, Sandra; Wolbring, Gregor; Wong, Man-Ling; Voordouw, Gerrit

2013-08-26

356

Tetracycline as a selector for resistant bacteria in activated sludge  

Microsoft Academic Search

Tetracycline, one of the most widely used antibiotics, is excreted into wastewater after consumption by humans and animals. The focus of this research was to evaluate the fate of tetracycline resistant bacteria in the activated sludge process as a function of tetracycline loading. The studies were conducted with aerobic biological sequencing batch reactors (SBRs). When comparing 250?gl?1 tetracycline fed SBRs

Sungpyo Kim; James N. Jensen; Diana S. Aga; A. Scott Weber

2007-01-01

357

Effect of carbon starvation on toluene degradation activity by toluene monooxygenase-expressing bacteria  

Microsoft Academic Search

Subsurface bacteria commonly exist in a starvation state with only periodic exposure to utilizable sources of carbon and energy. In this study, the effect of carbon starvation on aerobic toluene degradation was quantitatively evaluated with a selection of bacteria representing all the known toluene oxygenase enzyme pathways. For all the investigated strains, the rate of toluene biodegradation decreased exponentially with

David R. Johnson; Jerome J. Kukor; Linda M. Abriola

2006-01-01

358

High rate aerobic treatment of brewery wastewater using the jet loop reactor  

Microsoft Academic Search

An aerobic Jet Loop Reactor (JLR) activated sludge process of 541. volume was used to investigate its suitability for the treatment of industrial wastewaters, specifically brewery wastewater. A loading rate of 50 kg COD\\/m3·d was achieved with 97% COD removal for a period of 5 weeks and although the settleability was found to be acceptable non-flocculating motile bacteria caused the

James C. Bloor; G. K. Anderson; A. R. Willey

1995-01-01

359

Effectiveness of Resins in Neutralizing Antibiotic Activities in Bactec Plus Aerobic/F Culture Medium  

PubMed Central

Incorporating resins in blood culture media can effectively reduce the activities of several antibiotics. It was shown that the activities of some generally used antibiotics decreased by 80 to 90% within 2 h in Bactec Plus Aerobic/F resin-containing culture medium. Bactec vials containing resins were still found to be positive for bacteria when antibiotics were present. The addition of ?-lactamase shortened the detection time irrespective of the presence of resins.

Spaargaren, J.; van Boven, C. P. A.; Voorn, G. P.

1998-01-01

360

In Vitro Activity of Ceftobiprole against Aerobic and Anaerobic Strains Isolated from Diabetic Foot Infections  

Microsoft Academic Search

Against 443 aerobic and anaerobic bacteria isolated from diabetic foot infections, ceftobiprole MICs (g\\/ml) at which 90% of the isolates tested were inhibited were as follows: methicillin-resistant Staphylococcus aureus, 1; methicillin-susceptible S. aureus and Staphylococcus lugdunensis, 0.5; Anaerococcus prevotii, 0.125; Finegoldia magna, 0.5; Peptoniphilus asaccharolyticus ,1 ;Peptostreptococcus anaerobius ,4 ;Escherichia coli and Enterobacter species, 0.125; Klebsiella species, 2; and Pseudomonas

Ellie J. C. Goldstein; Diane M. Citron; C. Vreni Merriam; Yumi A. Warren; Kerin L. Tyrrell; Helen T. Fernandez

2006-01-01

361

In Vitro Activity of Ceftobiprole against Aerobic and Anaerobic Strains Isolated from Diabetic Foot Infections?  

PubMed Central

Against 443 aerobic and anaerobic bacteria isolated from diabetic foot infections, ceftobiprole MICs (?g/ml) at which 90% of the isolates tested were inhibited were as follows: methicillin-resistant Staphylococcus aureus, 1; methicillin-susceptible S. aureus and Staphylococcus lugdunensis, 0.5; Anaerococcus prevotii, 0.125; Finegoldia magna, 0.5; Peptoniphilus asaccharolyticus, 1; Peptostreptococcus anaerobius, 4; Escherichia coli and Enterobacter species, 0.125; Klebsiella species, 2; and Pseudomonas aeruginosa, 8.

Goldstein, Ellie J. C.; Citron, Diane M.; Merriam, C. Vreni; Warren, Yumi A.; Tyrrell, Kerin L.; Fernandez, Helen T.

2006-01-01

362

Biodegradation of azo dyes in a sequential anaerobic–aerobic system  

Microsoft Academic Search

A sequential anaerobic–aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent-contaminated\\u000a soil was used to degrade sulfonated azo dyes Orange G (OG), Amido black 10B (AB), Direct red 4BS (DR) and Congo red (CR).\\u000a Under anaerobic conditions in a fixed-bed column using glucose as co-substrate, the azo dyes were reduced and amines were\\u000a released by

P. Rajaguru; K. Kalaiselvi; M. Palanivel; V. Subburam

2000-01-01

363

Genome Sequence of the Mesophilic Thermotogales Bacterium Mesotoga prima MesG1.Ag.4.2 Reveals the Largest Thermotogales Genome To Date  

SciTech Connect

Here we describe the genome of Mesotoga prima MesG1.Ag4.2, the first genome of a mesophilic Thermotogales bacterium. Mesotoga prima was isolated from a polychlorinated biphenyl (PCB)-dechlorinating enrichment culture from Baltimore Harbor sediments. Its 2.97 Mb genome is considerably larger than any previously sequenced Thermotogales genomes, which range between 1.86 and 2.30 Mb. This larger size is due to both higher numbers of protein-coding genes and larger intergenic regions. In particular, the M. prima genome contains more genes for proteins involved in regulatory functions, for instance those involved in regulation of transcription. Together with its closest relative, Kosmotoga olearia, it also encodes different types of proteins involved in environmental and cell-cell interactions as compared with other Thermotogales bacteria. Amino acid composition analysis of M. prima proteins implies that this lineage has inhabited low-temperature environments for a long time. A large fraction of the M. prima genome has been acquired by lateral gene transfer (LGT): a DarkHorse analysis suggests that 766 (32%) of predicted protein-coding genes have been involved in LGT after Mesotoga diverged from the other Thermotogales lineages. A notable example of a lineage-specific LGT event is a reductive dehalogenase gene - a key enzyme in dehalorespiration, indicating M. prima may have a more active role in PCB dechlorination than was previously assumed.

Zhaxybayeva, Olga [Dartmouth College; Swithers, Kristen S [University of Connecticut, Storrs; Foght, Julia [University of Alberta, Edmondton, Canada; Green, Anna G. [University of Connecticut; Bruce, David [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Teshima, Hazuki [Los Alamos National Laboratory (LANL); Han, James [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Dlutek, Marlena [Dalhousie University, Halifax, Nova Scotia, CANADA; Doolittle, W. Ford [Dalhousie University, Halifax, Nova Scotia, CANADA; Noll, Kenneth M [University of Connecticut, Storrs; Nesbo, Camilla [University of Oslo, Norway

2012-01-01

364

Aerobic and anaerobic PCB biodegradation in the environment.  

PubMed Central

Studies have identified two distinct biological processes capable of biotransforming polychlorinated biphenyls (PCBs): aerobic oxidative processes and anaerobic reductive processes. It is now known that these two complementary activities are occurring naturally in the environment. Anaerobic PCB dechlorination, responsible for the conversion of highly chlorinated PCBs to lightly chlorinated ortho-enriched congeners, has been documented extensively in the Hudson River and has been observed at many other sites throughout the world. The products from this anaerobic process are readily degradable by a wide range of aerobic bacteria, and it has now been shown that this process is occurring in surficial sediments in the Hudson River. The widespread anaerobic dechlorination of PCBs that has been observed in many river and marine sediments results in reduction of both the potential risk from and potential exposure to PCBs. The reductions in potential risk include reduced dioxinlike toxicity and reduced carcinogenicity. The reduced PCB exposure realized upon dechlorination is manifested by reduced bioaccumulation in the food chain and by the increased anaerobic degradability of these products.

Abramowicz, D A

1995-01-01

365

Adaptation of aerobic respiration to low O2 environments.  

PubMed

Aerobic respiration in bacteria, Archaea, and mitochondria is performed by oxygen reductase members of the heme-copper oxidoreductase superfamily. These enzymes are redox-driven proton pumps which conserve part of the free energy released from oxygen reduction to generate a proton motive force. The oxygen reductases can be divided into three main families based on evolutionary and structural analyses (A-, B- and C-families), with the B- and C-families evolving after the A-family. The A-family utilizes two proton input channels to transfer protons for pumping and chemistry, whereas the B- and C-families require only one. Generally, the B- and C-families also have higher apparent oxygen affinities than the A-family. Here we use whole cell proton pumping measurements to demonstrate differential proton pumping efficiencies between representatives of the A-, B-, and C-oxygen reductase families. The A-family has a coupling stoichiometry of 1 H(+)/e(-), whereas the B- and C-families have coupling stoichiometries of 0.5 H(+)/e(-). The differential proton pumping stoichiometries, along with differences in the structures of the proton-conducting channels, place critical constraints on models of the mechanism of proton pumping. Most significantly, it is proposed that the adaptation of aerobic respiration to low oxygen environments resulted in a concomitant reduction in energy conservation efficiency, with important physiological and ecological consequences. PMID:21844375

Han, Huazhi; Hemp, James; Pace, Laura A; Ouyang, Hanlin; Ganesan, Krithika; Roh, Jung Hyeob; Daldal, Fevzi; Blanke, Steven R; Gennis, Robert B

2011-08-15

366

Adaptation of aerobic respiration to low O2 environments  

PubMed Central

Aerobic respiration in bacteria, Archaea, and mitochondria is performed by oxygen reductase members of the heme-copper oxidoreductase superfamily. These enzymes are redox-driven proton pumps which conserve part of the free energy released from oxygen reduction to generate a proton motive force. The oxygen reductases can be divided into three main families based on evolutionary and structural analyses (A-, B- and C-families), with the B- and C-families evolving after the A-family. The A-family utilizes two proton input channels to transfer protons for pumping and chemistry, whereas the B- and C-families require only one. Generally, the B- and C-families also have higher apparent oxygen affinities than the A-family. Here we use whole cell proton pumping measurements to demonstrate differential proton pumping efficiencies between representatives of the A-, B-, and C-oxygen reductase families. The A-family has a coupling stoichiometry of 1 H+/e-, whereas the B- and C-families have coupling stoichiometries of 0.5 H+/e-. The differential proton pumping stoichiometries, along with differences in the structures of the proton-conducting channels, place critical constraints on models of the mechanism of proton pumping. Most significantly, it is proposed that the adaptation of aerobic respiration to low oxygen environments resulted in a concomitant reduction in energy conservation efficiency, with important physiological and ecological consequences.

Han, Huazhi; Hemp, James; Pace, Laura A.; Ouyang, Hanlin; Ganesan, Krithika; Roh, Jung Hyeob; Daldal, Fevzi; Blanke, Steven R.; Gennis, Robert B.

2011-01-01

367

Fixed-bed fermentation of rice straw and chicken manure using a mixed culture of marine mesophilic microorganisms  

Microsoft Academic Search

A mixture of rice straw (80%) and chicken manure (20%) was pretreated and fermented to carboxylic acids by using a mixed culture of marine mesophilic microorganisms. Two sets of four fermentors, built from PVC pipes, were used for both biomass pretreatment and fermentation. Four 1L fermentors (F1–F4) were arranged in series, where liquid fermentation products were transferred from one fermentor

Frank K. Agbogbo; Mark T. Holtzapple

2007-01-01

368

Mesophilic and Thermophilic Conditions Select for Unique but Highly Parallel Microbial Communities to Perform Carboxylate Platform Biomass Conversion  

Microsoft Academic Search

The carboxylate platform is a flexible, cost-effective means of converting lignocellulosic materials into chemicals and liquid fuels. Although the platform's chemistry and engineering are well studied, relatively little is known about the mixed microbial communities underlying its conversion processes. In this study, we examined the metagenomes of two actively fermenting platform communities incubated under contrasting temperature conditions (mesophilic 40°C; thermophilic

Emily B. Hollister; Andrea K. Forrest; Heather H. Wilkinson; Daniel J. Ebbole; Susannah G. Tringe; Stephanie A. Malfatti; Mark T. Holtzapple; Terry J. Gentry

2012-01-01

369

Comparative genomics of the mesophilic cellulosome?producing Clostridium cellulovorans and its application to biofuel production via consolidated bioprocessing  

Microsoft Academic Search

Clostridium cellulovorans is an anaerobic, mesophilic bacterium that efficiently degrades native substrates in soft biomass such as corn fibre and rice straw by producing an extracellular enzyme complex called the cellulosomes. By examining genome sequences from multiple Clostridium species, comparative genomics offers new insight into genome evolution and the way natural selection moulds functional DNA sequence evolution. Recently, we reported

Yutaka Tamaru; Hideo Miyake; Kouichi Kuroda; Mitsuyoshi Ueda; Roy H. Doi

2010-01-01

370

Discrimination of Psychrotrophic and Mesophilic Strains of the Bacillus cereus Group by PCR Targeting of Major Cold Shock Protein Genes  

Microsoft Academic Search

Detection of psychrotrophic strains (those able to grow at or below 7°C) of the Bacillus cereus group (Bacillus cereus, Bacillus thuringiensis, and Bacillus mycoides) in food products is at present extremely slow with conven- tional microbiology. This is due to an inability to discriminate these cold-adapted strains from their mesophilic counterparts (those able to grow only above 7°C) by means

KEVIN P. FRANCIS; RALF MAYR; FELIX VON STETTEN; GORDON S. A. B. STEWART; SIEGFRIED SCHERER

1998-01-01

371

Effect of ultrasound pretreatment in mesophilic and thermophilic anaerobic digestion with emphasis on naphthalene and pyrene removal  

Microsoft Academic Search

In many anaerobic digestion processes for the treatment of the sludge produced in wastewater treatment plants, the hydrolysis of the organic matter has been identified as the rate limiting step. This study is focused on the effect of ultrasonic pretreatment of raw sewage sludge before being fed to the mesophilic and the thermophilic anaerobic digestion. From particle size reduction, COD

T. Benabdallah El-Hadj; J. Dosta; R. Márquez-Serrano; J. Mata-Álvarez

2007-01-01

372

Hydrolysis and acidification of dewatered sludge under mesophilic, thermophilic and extreme thermophilic conditions: Effect of pH.  

PubMed

This study investigated the effect of pH (uncontrolled, 8.0, 10.0 and 12.0) and temperature (mesophilic, thermophilic and extreme thermophilic) on hydrolysis and acidification of dewatered sludge in 7-day batch fermentation experiment. Solublization of COD, protein and carbohydrates as well as concentration and composition of VFAs were investigated. Sludge hydrolysis was enhanced with higher pH and temperature. The maximum SCOD, soluble protein and carbohydrates was observed at pH 12.0 at extreme thermophilic condition. The maximum VFAs yield was obtained at thermophilic and was 2.15 times that at mesophilic condition, but it took more time to reach the maximum. The VFAs consisted of acetic, propionic, iso-butyric, n-butyric, iso-valeric, and n-valeric acids, and acetic acid was the prevalent product in most cases except for uncontrolled pH and pH 8.0 at mesophilic condition. The methane production was as follows: pH 8.0>pH 10.0>uncontrolled (0.015)>pH 12.0; mesophilic>thermophilic>extreme thermophilic. PMID:24077155

Liu, Xiaoguang; Dong, Bin; Dai, Xiaohu

2013-08-27

373

Presence of beta-lactamase-producing bacteria and beta-lactamase activity in abscesses.  

PubMed

The presence of beta-lactamase-producing bacteria (BLPB) in abscesses was investigated in 109 abscesses. Single isolates were recovered in 23 (21%) instances and were predominantly Staphylococcus aureus. The other abscesses yielded growth of two or more aerobic and/or anaerobic organisms. Aerobic bacteria were recovered in 28 (26%) of the aspirates, anaerobic bacteria in 41 (38%), and mixed aerobic and anaerobic bacteria in 40 (36%). A total of 362 isolates (247 anaerobes and 115 aerobes) were recovered, accounting for 3.3 isolates per specimen (2.2 anaerobes and 1.1 aerobes). One hundred beta-lactamase-producing organisms were recovered in 88 (77%) specimens. These included all 28 isolates of Bacteroides fragilis, 18 of 30 Bacteroides melaninogenicus, 42 of 43 S. aureus, and 11 of 14 Escherichia coli. Beta-lactamase activity was detected in 40 (55%) of the purulent specimens when using the chromogenic cephalosporin nitrocefin method. These data demonstrate the presence of aerobic and anaerobic BLPB in abscesses. PMID:3487973

Brook, I

1986-07-01

374

Enzymes and genes involved in aerobic alkane degradation.  

PubMed

Alkanes are major constituents of crude oil. They are also present at low concentrations in diverse non-contaminated because many living organisms produce them as chemo-attractants or as protecting agents against water loss. Alkane degradation is a widespread phenomenon in nature. The numerous microorganisms, both prokaryotic and eukaryotic, capable of utilizing alkanes as a carbon and energy source, have been isolated and characterized. This review summarizes the current knowledge of how bacteria metabolize alkanes aerobically, with a particular emphasis on the oxidation of long-chain alkanes, including factors that are responsible for chemotaxis to alkanes, transport across cell membrane of alkanes, the regulation of alkane degradation gene and initial oxidation. PMID:23755043

Wang, Wanpeng; Shao, Zongze

2013-05-28

375

Prevalence of toxicogenic bacteria in some foods and detection of Bacillus cereus and Staphylococcus aureus enterotoxin genes using multiplex PCR  

Microsoft Academic Search

Thirty-three food samples representing seven different food products were collected from the market in Sharkia Governorate\\u000a (Egypt) and analyzed for their bacterial burden, including total mesophilic bacteria, spore formers, Staphylococcus aureus, and Bacillus cereus, using specific and selective nutrient media. The identified strains were screened for their virulence factors using the\\u000a agar diffusion method. B. cereus strains CH, GT1, LB3,

Mohamed A. Abdou; Nadia Mohammed Awny; Azza Abl-Elaziz M. Abozeid

376

Biodegradability and mesophilic co-digestion of municipal sludge and scum.  

PubMed

The objective of this study is to investigate and optimize the co-digestion of scum with thickened waste activated sludge (TWAS) and primary sludge (PS) undergoing mesophilic anaerobic digestion. The effect of scum loading on the co-digestion of PS, TWAS and scum has shown to have a significant impact on the ultimate cumulative biogas production and on the specific biogas production between 20 and 40 days of digestion, while the effects of the scum holding time within the scum concentrator and temperature of the scum concentrator did not demonstrate a significant effect on the ultimate or specific biogas production. The study demonstrates that care must be taken to avoid inhibitory effects and potential souring of digesters due to scum overloading and specifically scum overloading in combination with long holding times of scum within the scum concentrator at elevated temperatures. PMID:23553004

Young, Bradley; Delatolla, Robert; Kennedy, Kevin

2013-04-04

377

Column bioleaching of uranium embedded in granite porphyry by a mesophilic acidophilic consortium.  

PubMed

A mesophilic acidophilic consortium was enriched from acid mine drainage samples collected from several uranium mines in China. The performance of the consortium in column bioleaching of low-grade uranium embedded in granite porphyry was investigated. The influences of several chemical parameters on uranium extraction in column reactor were also investigated. A uranium recovery of 96.82% was achieved in 97 days column leaching process including 33 days acid pre-leaching stage and 64 days bioleaching stage. It was reflected that indirect leaching mechanism took precedence over direct. Furthermore, the bacterial community structure was analyzed by using Amplified Ribosomal DNA Restriction Analysis. The results showed that microorganisms on the residual surface were more diverse than that in the solution. Acidithiobacillus ferrooxidans was the dominant species in the solution and Leptospirillum ferriphilum on the residual surface. PMID:21316943

Qiu, Guanzhou; Li, Qian; Yu, Runlan; Sun, Zhanxue; Liu, Yajie; Chen, Miao; Yin, Huaqun; Zhang, Yage; Liang, Yili; Xu, Lingling; Sun, Limin; Liu, Xueduan

2011-01-22

378

Methane production in an UASB reactor operated under periodic mesophilic-thermophilic conditions.  

PubMed

Methane production was studied in a laboratory-scale 10 L anaerobic upflow sludge bed (UASB) reactor with periodic variations of the reactor temperature. On a daily basis the temperature was varied between 35 and 45 degrees C or 35 and 55 degrees C with a heating period of 6 h. Each temperature increase was accompanied by an increase in methane production and a decrease in the concentration of soluble organic matter in the effluent. In comparison to a reactor operated at 35 degrees C, a net increase in methane production of up to 22% was observed. Batch activity tests demonstrated a tolerance of mesophilic methanogenic populations to short-term, 2-6 h, temperature increases, although activity of acetoclastic methanogens decreased after 6 h exposure to a temperature of 55 degrees C. 16S sequencing of DGGE bands revealed proliferation of temperature-tolerant Methanospirillum hungatii sp. in the reactor. PMID:18383125

Bourque, J-S; Guiot, S R; Tartakovsky, B

2008-08-15

379

Biodegradation of PAH and DEHP micro-pollutants in mesophilic and thermophilic anaerobic sewage sludge digestion.  

PubMed

Anaerobic digestion for the treatment of sludge in wastewater treatment plants has been reported to produce a low organic loaded effluent with an acceptable economic cost. But in the last years, new regulations and the increasing sludge production invite us to find an alternative and/or to improve the process efficiency. Moreover, the use of the effluent as fertilizer in agriculture imposes more restrictions on digestion process product and its micropollutant contents to protect the environment. In this study, a performance of the anaerobic digestion under mesophilic and thermophilic conditions at different hydraulic retention times (HRT) is assessed and the removal efficiencies of two important compounds or family compounds (Polycyclic Aromatic Hydrocarbons, PAH, and Di-2-(Ethyl-Hexyl)-Phthalate, DEHP) are evaluated. A positive effect of thermophilic temperature was observed on both micropollutants' biodegradation. However, HRT effect also had an important role for DEHP and low molecular weighted PAH removal. PMID:16784194

Benabdallah El-Hadj, T; Dosta, J; Mata-Alvarez, J

2006-01-01

380

Mutational Analysis of Differences in Thermostability between Histones from Mesophilic and Hyperthermophilic Archaea  

PubMed Central

Amino acid residues responsible for the large difference in thermostability between HMfB and HFoB, archaeal histones from the hyperthermophile Methanothermus fervidus and the mesophile Methanobacterium formicicum, respectively, have been identified by site-specific mutagenesis. The thermal denaturation of ?70 archaeal histone variants has been monitored by circular dichroism, and the data generated were fit to a two-state unfolding model (dimer?two random coil monomers) to obtain a standard-state (1M) melting temperature for each variant dimer. The results of single-, double-, and triple-residue substitutions reveal that the much higher stability of rHMfB dimers, relative to rHFoB dimers, is conferred predominantly by improved intermolecular hydrophobic interactions near the center of the histone dimer core and by additional favorable ion pairs on the dimer surface.

Li, Wen-Tyng; Shriver, John W.; Reeve, John N.

2000-01-01

381

Dry anaerobic digestion of food waste under mesophilic conditions: performance and methanogenic community analysis.  

PubMed

The performance of dry anaerobic digestion (AD) of food waste was investigated under mesophilic conditions and the methanogenic community was investigated using 454 pyrosequencing. Stable dry AD was achieved by hydraulic retention time (HRT) control without the addition of alkali agents. The average CH4 production rate, CH4 content, and volatile solid reduction rate were 2.51±0.17m(3)/m(3)/d, 66±2.1%, and 65.8±1.22%, respectively, at an HRT of 40d. The methanogenic community of the seed sludge experienced a significant reduction in genus diversity from 18 to 4 and a dominant methanogenic shift from hydrogenotrophic to acetoclastic groups after the acclimation under dry condition. Almost all sequences of the dry anaerobic digester were closely related with those of Methanosarcina thermophila with similarity of 96.4-99.1%. The experimental results would serve as useful information to understand the dry AD system. PMID:23347929

Cho, Si-Kyung; Im, Wan-Taek; Kim, Dong-Hoon; Kim, Moon-Hwan; Shin, Hang-Sik; Oh, Sae-Eun

2012-12-29

382

Escherichia coli inactivation kinetics in anaerobic digestion of dairy manure under moderate, mesophilic and thermophilic temperatures.  

PubMed

Batch anaerobic digestion experiments using dairy manure as feedstocks were performed at moderate (25°C), mesophilic (37°C), and thermophilic (52.5°C) temperatures to understand E. coli, an indicator organism for pathogens, inactivation in dairy manure. Incubation periods at 25, 37, and 52.5°C, were 61, 41, and 28 days respectively. Results were used to develop models for predicting E. coli inactivation and survival in anaerobic digestion. For modeling we used the decay of E. coli at each temperature to calculate the first-order inactivation rate coefficients, and these rates were used to formulate the time - temperature - E. coli survival relationships. We found the inactivation rate coefficient at 52.5°C was 17 and 15 times larger than the inactivation rate coefficients at 25 and 37°C, respectively. Decimal reduction times (D10; time to achieve one log removal) at 25, 37, and 52.5°C, were 9 -10, 7 - 8 days, and < 1 day, respectively. The Arrhenius correlation between inactivation rate coefficients and temperatures over the range 25 -52.5°C was developed to understand the impacts of temperature on E. coli inactivation rate. Using this correlation, the time - temperature - E. coli survival relationships were derived. Besides E. coli inactivation, impacts of temperature on biogas production, methane content, pH change, ORP, and solid reduction were also studied. At higher temperatures, biogas production and methane content was greater than that at low temperatures. While at thermophilic temperature pH was increased, at mesophilic and moderate temperatures pH were reduced over the incubation period. These results can be used to understand pathogen inactivation during anaerobic digestion of dairy manure, and impacts of temperatures on performance of anaerobic digesters treating dairy manure. PMID:21906374

Pandey, Pramod K; Soupir, Michelle L

2011-07-15

383

Aerobic thermophilic treatment of farm slurry and food wastes  

Microsoft Academic Search

The review discusses the aerobic treatments for farm slurry and food wastes and concentrates in particular on the thermophilic aerobic treatments. Methods are discussed under the heading of chemical, physical and other treatments. From those methods considered, the most suitable physical–microbiological treatment are aerobic thermophilic treatments. The main problem faced in aerobic thermophilic treatments could be the foaming formation during

Mohammed Mohaibes; Helvi Heinonen-Tanski

2004-01-01

384

Conditioning and Aerobics for Older Americans.  

ERIC Educational Resources Information Center

|A class designed for the maintenance and gradual improvement of senior citizens' physical fitness includes relaxation training, flexibility and stretching exercises, interval training activities (designed as a link between less strenuous exercise and more strenuous activities), and aerobic exercises. (CJ)|

Hansen, Joyce

1980-01-01

385

The Energetics of Aerobic versus Anaerobic Respiration.  

ERIC Educational Resources Information Center

|Background information, laboratory procedures, and a discussion of the results of an experiment designed to investigate the difference in energy gained from the aerobic and anaerobic oxidation of glucose are presented. Sample experimental and calculated data are included. (CW)|

Champion, Timothy D.; Schwenz, Richard W.

1990-01-01

386

Aerobic Decomposition of Algae and Nutrient Regeneration.  

National Technical Information Service (NTIS)

This study presents definitive hypotheses for natural aerobic algal decomposition and nutrient regeneration. Emphasis is placed on the significance of the refractory organic fraction of algae in the decay and nutrient regeneration processes. Other variabl...

W. J. Jewell P. L. McCarty

1968-01-01

387

Effects of aerobic exercise on anxiety sensitivity  

Microsoft Academic Search

Anxiety sensitivity is a known precursor to panic attacks and panic disorder, and involves the misinterpretation of anxiety-related sensations. Aerobic exercise has been shown to reduce generalized anxiety, and may also reduce anxiety sensitivity through exposure to feared physiological sensations. Accordingly, 54 participants with elevated anxiety sensitivity scores completed six 20-min treadmill exercise sessions at either a high-intensity aerobic (n=29)

Joshua J Broman-Fulks; Mitchell E Berman; Brian A Rabian; Michael J Webster

2004-01-01

388

Aerobic endurance training improves soccer performance  

Microsoft Academic Search

HELGERUD, J., L. C. ENGEN, U. WISLØFF, and J. HOFF. Aerobic endurance training improves soccer performance.Med. Sci. Sports Exerc., Vol. 33, No. 11, 2001, pp. 1925-1931. Purpose: The aim of the present study was to study the effects of aerobic training on performance during soccer match and soccer specific tests. Methods: Nineteen male elite junior soccer players, age 18.1 0.8

JAN HELGERUD; LARS CHRISTIAN ENGEN; JAN HOFF

2001-01-01

389

Bacteria in food packaging paper and board.  

PubMed

The bacteria of food packaging paper and board were studied. Most of the aerobic strains were spore-formers; members of the genus Bacillus with B. cereus group (B. cereus, B. mycoides, B. thuringiensis), B. polymyxa group (B. polymyxa, B. circulans, B. macerans, B. pabuli), B. brevis and B. licheniformis predominated. The main source of spore-forming bacteria in paper and board was the broke (rejected paper or board, which is repulped and recycled into the process). Gram-negative bacteria were rare in paper and board in spite of their abundance in the stock. A strain of B. pumilus forming clumping, hairy spores may be of significance in aseptic packaging. PMID:1917722

Väisänen, O M; Mentu, J; Salkinoja-Salonen, M S

1991-08-01

390

Survey of petroleum-degrading bacteria in coastal waters of Sunderban Biosphere Reserve  

Microsoft Academic Search

A survey of petroleum-degrading bacteria was carried out in the Indian part of deltaic Sunderbans to evaluate the distribution of the naturally occurring petroleum-degrading aerobic bacteria. Bacteriological analysis of surface water samples collected from five different locations in the Hooghly–Matla river mouth showed that, depending on the location, 0.08–2.0% of the heterotrophic bacteria culturable in marine agar medium could degrade

Subarna Roy; Dipak Hens; Debabrata Biswas; Dipa Biswas; Ranajit Kumar

2002-01-01

391

Size-dependent antibacterial activities of silver nanoparticles against oral anaerobic pathogenic bacteria.  

PubMed

Dental caries and periodontal disease are widespread diseases for which microorganism infections have been identified as the main etiology. Silver nanoparticles (Ag Nps) were considered as potential control oral bacteria infection agent due to its excellent antimicrobial activity and non acute toxic effects on human cells. In this work, stable Ag Nps with different sizes (~5, 15 and 55 nm mean values) were synthesized by using a simple reduction method or hydrothermal method. The Nps were characterized by powder X-ray diffraction, transmission electron microscopy and UV-vis absorption spectroscopy. The antibacterial activities were evaluated by colony counting assay and growth inhibition curve method, and corresponding minimum inhibitory concentration (MIC) against five anaerobic oral pathogenic bacteria and aerobic bacteria E. coli were determined. The results showed that Ag Nps had apparent antibacterial effects against the anaerobic oral pathogenic bacteria and aerobic bacteria. The MIC values of 5-nm Ag against anaerobic oral pathogenic bacteria A. actinomycetemcomitans, F. nuceatum, S. mitis, S. mutans and S. sanguis were 25, 25, 25, 50 and 50 ?g/mL, respectively. The aerobic bacteria were more susceptible to Ag NPs than the anaerobic oral pathogenic bacteria. In the mean time, Ag NPs displayed an obvious size-dependent antibacterial activity against the anaerobic bacteria. The 5-nm Ag presents the highest antibacterial activity. The results of this work indicated a potential application of Ag Nps in the inhibition of oral microorganism infections. PMID:23440430

Lu, Zhong; Rong, Kaifeng; Li, Ju; Yang, Hao; Chen, Rong

2013-02-26

392

Submerged filter biotreatment of hazardous leachate in aerobic, anaerobic, and anaerobic/aerobic systems  

SciTech Connect

Aerobic, anaerobic and anaerobic/aerobic biotreatment of an industrial hazardous waste landfill leachate was evaluated in bench scale biofilm reactor systems operated under steady-and non-steady-state conditions. The leachate contained volatile and semi-volatile organics that exceeded the best-demonstrated-available-technology (BDAT) standard established for multi-source leachate wastewater under the Resources Conservation and Recovery Act (RCRA). The influent leachate stream was continuously applied to three parallel systems: (1) an upflow anaerobic filter followed by a submerged aerobic filter, both plastic packing, (2) an anaerobic granular activated carbon column, and (3) an upflow, plastic packed aerobic filter. All systems achieved steady-state COD removals of 66-82 percent. The sequential anaerobic/aerobic filter system was most resistant to hydraulic and organic shock loading, whereas the aerobic filter performance deteriorated significantly. Though transformations of specific chemical compounds were achieved in both anaerobic and aerobic treatment, the sequential anaerobic/aerobic system was cost effective for meeting BDAT standards for hazardous organics. 25 refs., 6 figs., 15 tabs.

Smith, D.P. [Utah State Univ., Logan, UT (United States)

1995-12-31

393

Aerobic Excercise and Research Opportunities to Benefit Impaired Children. (Project AEROBIC). Final Report.  

ERIC Educational Resources Information Center

The final report summarizes accomplishments of Project AEROBIC (Aerobic Exercise and Research Opportunities to Benefit Impaired Children), which provided a physical education exercise program for severely, profoundly, and multiply handicapped children aged 10-21. Activities are outlined for the 3 year period and include modification of exercise…

Idaho Univ., Moscow.

394

Four weeks of training with different aerobic workload distributions – Effect on aerobic performance  

Microsoft Academic Search

Although numerous authors have studied the effect of different training procedures on athlete's resistance performance, there are no studies on how the improvement of aerobic resistance is affected by the distribution of training loads. This research sets out to analyse the effectiveness on aerobic activity of distributions with a constant load (CON) and with increments in intensity (INC) over a

Vicente Javier Clemente Suárez; Jose M. González-Ravé

2011-01-01

395

Detection and distribution of food-borne bacteria in ready-to-eat foods in Korea  

Microsoft Academic Search

In this study, the contamination levels of total aerobic plate counts, Escherichia coli and various pathogenic bacteria in ready-to-eat (RTE) foods were investigated in Korea. A total of 634 samples were purchased\\u000a randomly from 47 stores located in 3 different provinces. The aerobic plate count levels of RTE occurred in a relatively wide\\u000a range, of 1.0–7.9 log CFU\\/g. E. coli

Joon Il Cho; Soon Ho Lee; Ji Su Lim; Yoon Jeoung Koh; Hyo Sun Kwak; In Gyun Hwang

2011-01-01

396

An effective way to select slow-growing nitrifying bacteria by providing a dynamic environment  

Microsoft Academic Search

In this study, two laboratory scale sequencing batch reactors (SBRs) were conducted to study the stability of aerobic granules.\\u000a The strategy was involved in stepwise increase in ammonium (NH4+-N) concentration in the influent. Results showed that the activity of nitrifying bacteria and diameter of the aerobic granules\\u000a significantly increased with gradually increasing NH4+-N, which reached persistently new balances by homeostasis.

Li-Ping Xia; Han-Min Zhang; Xin-Hua Wang

2007-01-01

397

Bosea minatitlanensis sp. nov., a strictly aerobic bacterium isolated from an anaerobic digester.  

PubMed

A strictly aerobic, mesophilic bacterium, strain AMX 51(T), was isolated from anaerobic digester sludge. Cells were Gram-negative, motile, non-sporulating, straight to curved rods with one polar flagellum. The isolate had phenotypic traits of the genus Bosea, including cellular fatty acid and substrate utilization profiles. Physiological characteristics and antibiotic susceptibility were determined. Phylogenetic analysis revealed that strain AMX 51(T) was a member of the alpha-Proteobacteria, most closely related to Bosea thiooxidans DSM 9653(T) (similarity of 98.88 %). Methylobacterium organophilum JCM 2833(T), Methylobacterium mesophilicum JCM 2829(T), Afipia clevelandensis DSM 7315(T), Afipia felis DSM 7326(T), Afipia broomeae DSM 7327(T), Blastobacter denitrificans LMG 8443(T) and Bradyrhizobium japonicum DSM 30131(T) showed significant 16S rRNA gene sequence similarities to strain AMX 51(T). The DNA G+C composition of strain AMX 51(T) was 68.5 mol%. DNA-DNA hybridization analysis revealed 44.2 and 15.1 % relatedness between strain AMX 51(T) and the respective type strains of Bosea thiooxidans and A. felis. Overall results suggest that strain AMX 51(T) (=DSM 13099(T)=ATCC 700918(T)=CIP 106457(T)) represents a novel species of the genus Bosea; the name Bosea minatitlanensis sp. nov. is proposed. PMID:13130002

Ouattara, Aboubakar S; Assih, Essokazi A; Thierry, Sébastien; Cayol, Jean-Luc; Labat, Marc; Monroy, Oscar; Macarie, Hervé

2003-09-01

398

Strength characteristics of aerobic granular sludge.  

PubMed

Aerobic granular sludge has a number of advantages over conventional activated sludge flocs, such as cohesive and strong matrix, fast settling characteristic, high biomass retention and ability to withstand high organic loadings, all aspects leading towards a compact reactor system. Still there are very few studies on the strength of aerobic granules. A procedure that has been used previously for anaerobic granular sludge strength analysis was adapted and used in this study. A new coefficient was introduced, called a stability coefficient (S), to quantify the strength of the aerobic granules. Indicators were also developed based on the strength analysis results, in order to categorize aerobic granules into three levels of strength, i.e. very strong (very stable), strong (stable) and not strong (not stable). The results indicated that aerobic granules grown on acetate were stronger (high density: >150 g T SSL(-1) and low S value: 5%) than granules developed on sewage as influent. A lower value of S indicates a higher stability of the granules. PMID:22233910

Nor-Anuar, A; Ujang, Z; van Loosdrecht, M C M; de Kreuk, M K; Olsson, G

2012-01-01

399

Bacterial degradation of benzoate: cross-regulation between aerobic and anaerobic pathways.  

PubMed

We have studied for the first time the transcriptional regulatory circuit that controls the expression of the box genes encoding the aerobic hybrid pathway used to assimilate benzoate via coenzyme A (CoA) derivatives in bacteria. The promoters responsible for the expression of the box cluster in the ?-proteobacterium Azoarcus sp., their cognate transcriptional repressor, the BoxR protein, and the inducer molecule (benzoyl-CoA) have been characterized. The BoxR protein shows a significant sequence identity to the BzdR transcriptional repressor that controls the bzd genes involved in the anaerobic degradation of benzoate. Because the boxR gene is present in all box clusters so far identified in bacteria, the BoxR/benzoyl-CoA regulatory system appears to be a widespread strategy to control this aerobic hybrid pathway. Interestingly, the paralogous BoxR and BzdR regulators act synergistically to control the expression of the box and bzd genes. This cross-regulation between anaerobic and aerobic pathways for the catabolism of aromatic compounds has never been shown before, and it may reflect a biological strategy to increase the cell fitness in organisms that survive in environments subject to changing oxygen concentrations. PMID:22303008

Valderrama, J Andrés; Durante-Rodríguez, Gonzalo; Blázquez, Blas; García, José Luis; Carmona, Manuel; Díaz, Eduardo

2012-02-02

400

The multiple evolutionary histories of dioxygen reductases: Implications for the origin and evolution of aerobic respiration.  

PubMed

Understanding the origin and evolution of cellular processes is fundamental to understand how biological activity has shaped the history of our planet. Among these, aerobic respiration is probably one of the most debated. We have applied a phylogenomics approach to investigate the origin and evolution of dioxygen reductases (O(2)Red), the key enzymes of aerobic respiratory chains. The distribution and phylogenetic analysis of the four types of O(2)Red (Cyt-bd and the A, B, and C families of heme-copper O(2)Red) from 673 complete bacterial and archaeal genomes show that these enzymes have very different evolutionary histories: Cyt-bd are of bacterial origin and were transferred to a few archaea; C-O(2)Red are of proteobacterial origin and were transferred to a few other bacteria; B-O(2)Red are of archaeal origin and were transferred to a few bacteria; and A-O(2)Red are the most ancient O(2)Red and were already present prior to the divergence of major present-day bacterial and archaeal phyla, thus before the emergence of Cyanobacteria and oxygenic photosynthesis. Implications for the origin and the evolution of aerobic respiration are discussed. PMID:18974088

Brochier-Armanet, Celine; Talla, Emmanuel; Gribaldo, Simonetta

2008-10-29

401

Carbon isotopic fractionation in lipids from methanotrophic bacteria: Relevance for interpretation of the geochemical record of biomarkers  

Microsoft Academic Search

Experiments with cultured aerobic methane oxidising bacteria confirm that their biomarker lipids will be significantly depleted in 13 C compared to the substrate. The methanotrophic bacteria Methylococcus capsulatus and Methylomonas methanica , grown on methane and using the RuMP cycle for carbon assimilation, show maximum 13 C fractionation of approximately 30%. in the resultant biomass. In M . capsulatus ,

Roger E. Summons; Linda L. Jahnke; Zarko Roksandic

1994-01-01

402

Effect of extracellular enzyme activity on digestion performance of mesophilic UASB reactor treating high-strength municipal wastewater  

Microsoft Academic Search

Effect of extracellular enzyme activity on digestion performance of up-flow anaerobic sludge blanket (UASB) reactor was investigated\\u000a for enhancement of anaerobic treatability of municipal wastewater. Two identical UASB reactors (9 L), namely Reactor-A (without\\u000a enzyme addition) and Reactor-B (with enzyme addition), were simultaneously operated at mesophilic conditions (32 ± 2 °C) with\\u000a a hydraulic retention time of 24 h. Preliminary test results showed that the

F. Ilter Turkdogan-Aydinol; Kaan Yetilmezsoy; Sezen Comez

2011-01-01

403

Profile of hydrolases and biogas production during two-stage mesophilic anaerobic digestion of solid potato waste  

Microsoft Academic Search

Two two-stage systems, one consisting of a solid-bed reactor for hydrolysis\\/acidification connected to an upflow anaerobic sludge blanket methanogenic reactor, and the other consisting of a solid-bed reactor connected to a methanogenic reactor packed with wheat straw biofilm carriers, were investigated with regard to hydrolytic enzymes and methane production during mesophilic anaerobic digestion of solid potato waste. Some of the

W. Parawira; M. Murto; J. S. Read; B. Mattiasson

2005-01-01

404

Novel genes for nitrite reductase and Amo-related proteins indicate a role of uncultivated mesophilic crenarchaeota in nitrogen cycling  

Microsoft Academic Search

Summary Mesophilic crenarchaeota are frequently found in ter- restrial and marine habitats worldwide, but despite their considerable abundance the physiology of these as yet uncultivated archaea has remained unknown. From a 1.2 Gb large-insert environmental fosmid library of a calcareous grassland soil, a 43 kb genomic fragment was isolated with a ribosomal RNA that shows its affiliation to group 1.1b

Alexander H. Treusch; Sven Leininger; Arnulf Kletzin; Stephan C. Schuster; Christa Schleper

2005-01-01

405

Genome Sequence of a Mesophilic Hydrogenotrophic Methanogen Methanocella paludicola, the First Cultivated Representative of the Order Methanocellales  

Microsoft Academic Search

We report complete genome sequence of a mesophilic hydrogenotrophic methanogen Methanocella paludicola, the first cultured representative of the order Methanocellales once recognized as an uncultured key archaeal group for methane emission in rice fields. The genome sequence of M. paludicola consists of a single circular chromosome of 2,957,635 bp containing 3004 protein-coding sequences (CDS). Genes for most of the functions

Sanae Sakai; Yoshihiro Takaki; Shigeru Shimamura; Mitsuo Sekine; Takahisa Tajima; Hiroki Kosugi; Natsuko Ichikawa; Eiji Tasumi; Aiko T. Hiraki; Ai Shimizu; Yumiko Kato; Rika Nishiko; Koji Mori; Nobuyuki Fujita; Hiroyuki Imachi; Ken Takai

2011-01-01

406

Waste activated sludge hydrolysis and short-chain fatty acids accumulation under mesophilic and thermophilic conditions: Effect of pH  

Microsoft Academic Search

The effect of pH (4.0–11.0) on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation under mesophilic and thermophilic conditions were investigated. The WAS hydrolysis increased markedly in thermophilic fermentation compared to mesophilic fermentation at any pH investigated. The hydrolysis at alkaline pHs (8.0–11.0) was greater than that at acidic pHs, but both of the acidic and alkaline

Peng Zhang; Yinguang Chen; Qi Zhou

2009-01-01

407

Comparative performance between temperature-phased and conventional mesophilic two-phased processes in terms of anaerobically produced bioenergy from food waste.  

PubMed

Comparative evaluation of bioenergy production from food waste was carried out with both a temperature-phased and a conventional mesophilic two-phased process at different organic loading rates (OLRs). No methane was detected in the temperature-phased thermophilic-acidogenic fermenter at all the OLRs tested. However, a significant amount of methane content was detected in the conventional two-phased mesophilic-acidogenic fermenter, with increments depending on the organic loading rate [from 17% at 3 g VS L(-1) day(-1) to 25% at 8 g VS L(-1) day(-1) (VS, volatile solid)]. Acetate and butyrate were the main volatile fatty acids (VFAs) in the temperature-phased thermophilic-acidogenic fermenter; conversely propionate was a major VFA in the conventional two-phased mesophilic-acidogenic fermenter. Through the chemical oxygen demand (COD) balance of both temperature-phased and conventional mesophilic two-phased processes, the fraction of the feed-COD converted to the hydrogen-COD in the thermophilic-acidogenic fermenter within the former process was estimated from 7.9 to 9.3%, with a peak at ORL of 6 g VS L(-1) day(-1), whereas it was quantified from 0.3 to 0.9% in the mesophilic-acidogenic fermenter within the latter one. Moreover, the fraction of the feed-COD converted to the methane-COD in the mesophilic-acidogenic fermenter within the conventional two-phased process ranged from 5.4 to 7.9%. On the other hand, conversion of the feed-COD to the methane-COD in the mesophilic-methanogenic fermenter of both temperature-phased and conventional mesophilic two-phased processes ranged from 66.2 to 72.3% and from 63.5 to 70.5%, respectively, with decrements related to the increase of organic loading rate. PMID:15751393

Youn, Jong-Ho; Shin, Hang-Sik

2005-02-01

408

Different Subsets of Enteric Bacteria Induce and Perpetuate Experimental Colitis in Rats and Mice  

PubMed Central

Resident bacteria are incriminated in the pathogenesis of experimental colitis and inflammatory bowel diseases. We investigated the relative roles of various enteric bacteria populations in the induction and perpetuation of experimental colitis. HLA-B27 transgenic rats received antibiotics (ciprofloxacin, metronidazole, or vancomycin-imipenem) in drinking water or water alone in either prevention or treatment protocols. Mice were treated similarly with metronidazole or vancomycin-imipenem before or after receiving 5% dextran sodium sulfate (DSS). Germfree transgenic rats were colonized with specific-pathogen-free enteric bacteria grown overnight either in anaerobic or aerobic atmospheres. Nontransgenic rats colonized with anaerobic bacteria served as negative controls. Although preventive metronidazole significantly attenuated colitis in transgenic rats and DSS-treated mice, it had no therapeutic benefit once colitis was established. Ciprofloxacin also partially prevented but did not treat colitis in B27 transgenic rats. In both animal models vancomycin-imipenem most effectively prevented and treated colitis. Germfree transgenic rats reconstituted with enteric bacteria grown under anaerobic conditions had more aggressive colitis than those associated with aerobic bacteria. These results suggest that a subset of resident luminal bacteria induces colitis, but that a complex interaction of commensal aerobic and anaerobic bacteria provides the constant antigenic drive for chronic immune-mediated colonic inflammation.

Rath, Heiko C.; Schultz, Michael; Freitag, Rene; Dieleman, Levinus A.; Li, Fengling; Linde, Hans-Jorg; Scholmerich, Jurgen; Sartor, R. Balfour

2001-01-01

409

Microbiological quality of freshwater prawns during storage  

Microsoft Academic Search

Microbiological quality analysis of freshwater prawns from three sampling sites in Peninsular Malaysia viz: Site 1- Kg. Jumbang, Negri Sembilan; Site 2- Kg. Cangkat Tin, Perak and Site 3- Kg. Cenderiang, Perak for total mesophilic and psychrophilic aerobic counts, proteolytic bacterial counts, histamine producing bacteria, cadaverine producing bacteria and putrescine producing bacteria in the prawns and pond water for the

Abu Bakar; M. Basri

2008-01-01

410

Mesophilic and Thermophilic Conditions Select for Unique but Highly Parallel Microbial Communities to Perform Carboxylate Platform Biomass Conversion  

PubMed Central

The carboxylate platform is a flexible, cost-effective means of converting lignocellulosic materials into chemicals and liquid fuels. Although the platform's chemistry and engineering are well studied, relatively little is known about the mixed microbial communities underlying its conversion processes. In this study, we examined the metagenomes of two actively fermenting platform communities incubated under contrasting temperature conditions (mesophilic 40°C; thermophilic 55°C), but utilizing the same inoculum and lignocellulosic feedstock. Community composition segregated by temperature. The thermophilic community harbored genes affiliated with Clostridia, Bacilli, and a Thermoanaerobacterium sp, whereas the mesophilic community metagenome was composed of genes affiliated with other Clostridia and Bacilli, Bacteriodia, ?-Proteobacteria, and Actinobacteria. Although both communities were able to metabolize cellulosic materials and shared many core functions, significant differences were detected with respect to the abundances of multiple Pfams, COGs, and enzyme families. The mesophilic metagenome was enriched in genes related to the degradation of arabinose and other hemicellulose-derived oligosaccharides, and the production of valerate and caproate. In contrast, the thermophilic community was enriched in genes related to the uptake of cellobiose and the transfer of genetic material. Functions assigned to taxonomic bins indicated that multiple community members at either temperature had the potential to degrade cellulose, cellobiose, or xylose and produce acetate, ethanol, and propionate. The results of this study suggest that both metabolic flexibility and functional redundancy contribute to the platform's ability to process lignocellulosic substrates and are likely to provide a degree of stability to the platform's fermentation processes.

Hollister, Emily B.; Forrest, Andrea K.; Wilkinson, Heather H.; Ebbole, Daniel J.; Tringe, Susannah G.; Malfatti, Stephanie A.; Holtzapple, Mark T.; Gentry, Terry J.

2012-01-01

411

Mesophilic and thermophilic conditions select for unique but highly parallel microbial communities to perform carboxylate platform biomass conversion.  

PubMed

The carboxylate platform is a flexible, cost-effective means of converting lignocellulosic materials into chemicals and liquid fuels. Although the platform's chemistry and engineering are well studied, relatively little is known about the mixed microbial communities underlying its conversion processes. In this study, we examined the metagenomes of two actively fermenting platform communities incubated under contrasting temperature conditions (mesophilic 40°C; thermophilic 55 °C), but utilizing the same inoculum and lignocellulosic feedstock. Community composition segregated by temperature. The thermophilic community harbored genes affiliated with Clostridia, Bacilli, and a Thermoanaerobacterium sp, whereas the mesophilic community metagenome was composed of genes affiliated with other Clostridia and Bacilli, Bacteriodia, ?-Proteobacteria, and Actinobacteria. Although both communities were able to metabolize cellulosic materials and shared many core functions, significant differences were detected with respect to the abundances of multiple Pfams, COGs, and enzyme families. The mesophilic metagenome was enriched in genes related to the degradation of arabinose and other hemicellulose-derived oligosaccharides, and the production of valerate and caproate. In contrast, the thermophilic community was enriched in genes related to the uptake of cellobiose and the transfer of genetic material. Functions assigned to taxonomic bins indicated that multiple community members at either temperature had the potential to degrade cellulose, cellobiose, or xylose and produce acetate, ethanol, and propionate. The results of this study suggest that both metabolic flexibility and functional redundancy contribute to the platform's ability to process lignocellulosic substrates and are likely to provide a degree of stability to the platform's fermentation processes. PMID:22761870

Hollister, Emily B; Forrest, Andrea K; Wilkinson, Heather H; Ebbole, Daniel J; Tringe, Susannah G; Malfatti, Stephanie A; Holtzapple, Mark T; Gentry, Terry J

2012-06-22

412

Anaerobic digestion of whole stillage from dry-grind corn ethanol plant under mesophilic and thermophilic conditions.  

PubMed

Anaerobic digestion of whole stillage from a dry-grind corn-based ethanol plant was evaluated by batch and continuous-flow digesters under thermophilic and mesophilic conditions. At whole corn stillage concentrations of 6348 to 50,786 mg total chemical oxygen demand (TCOD)/L, at standard temperature (0 °C) and pressure (1 atm), preliminary biochemical methane potential assays produced 88±8 L (49±5 L CH4) and 96±19 L (65±14 L CH4) biogas per L stillage from mesophilic and thermophilic digesters, respectively. Continuous-flow studies for the full-strength stillage (TCOD=254 g/L) at organic loadings of 4.25, 6.30 and 9.05 g TCOD/L days indicated unstable performance for the thermophilic digester. Among the sludge retention times (SRTs) of 60, 45 and 30 days tested, the mesophilic digestion was successful only at 60 days-SRT which does not represent a practical operation time for a large scale bioethanol plant. Future laboratory studies will focus on different reactor configurations to reduce the SRT needed in the digesters. PMID:20843681

Eskicioglu, Cigdem; Kennedy, Kevin J; Marin, Juan; Strehler, Benjamin

2010-08-24

413

The UDP N-Acetylgalactosamine 4-Epimerase Gene Is Essential for Mesophilic Aeromonas hydrophila Serotype O34 Virulence  

PubMed Central

Mesophilic Aeromonas hydrophila strains of serotype O34 typically express smooth lipopolysaccharide (LPS) on their surface. A single mutation in the gene that codes for UDP N-acetylgalactosamine 4-epimerase (gne) confers the O? phenotype (LPS without O-antigen molecules) on a strain in serotypes O18 and O34, but not in serotypes O1 and O2. The gne gene is present in all the mesophilic Aeromonas strains tested. No changes were observed for the LPS core in a gne mutant from A. hydrophila strain AH-3 (serotype O34). O34 antigen LPS contains N-acetylgalactosamine, while no such sugar residue forms part of the LPS core from A. hydrophila AH-3. Some of the pathogenic features of A. hydrophila AH-3 gne mutants are drastically reduced (serum resistance or adhesion to Hep-2 cells), and the gne mutants are less virulent for fish and mice compared to the wild-type strain. Strain AH-3, like other mesophilic Aeromonas strains, possess two kinds of flagella, and the absence of O34 antigen molecules by gne mutation in this strain reduced motility without any effect on the biogenesis of both polar and lateral flagella. The reintroduction of the single wild-type gne gene in the corresponding mutants completely restored the wild-type phenotype (presence of smooth LPS) independently of the O wild-type serotype, restored the virulence of the wild-type strain, and restored motility (either swimming or swarming).

Canals, Rocio; Jimenez, Natalia; Vilches, Silvia; Regue, Miguel; Merino, Susana; Tomas, Juan M.

2006-01-01

414

Without Salt, the 'Thermophilic' Protein Mth10b Is Just Mesophilic  

PubMed Central

Most proteins from thermophiles or hyperthermophiles are intrinsically thermostable. However, though Methanobacterium thermoautotrophicum ?H is a thermophilic archaeon with an optimal growth temperature of 65°C, Mth10b, an atypical member the Sac10b protein family from M. thermoautotrophicum ?H, seems not intrinsically thermostable. In this work, to clarify the molecular mechanism of Mth10b remaining stable under its physiological conditions, the thermodynamic properties of Mth10b were studied through equilibrium unfolding experiments performed at pH 7.0 monitored by circular dichroism (CD) spectra in detail. Our work demonstrated that Mth10b is not intrinsically thermostable and that due to the masking effect upon the large numbers of destabilizing electrostatic repulsions resulting from the extremely uneven distribution of charged residues over the surface of Mth10b, salt can contribute to the thermostability of Mth10b greatly. Considering that the intracellular salt concentration is high to 0.7 M, we concluded that salt is the key extrinsic factor to Mth10b remaining stable under its physiological conditions. In other word, without salt, ‘thermophilic’ protein Mth10b is just a mesophilic one.

Zhang, Nan; Pan, Xian-Ming; Ge, Meng

2012-01-01

415

Application of mechanical shear in an internal-recycle for the enhancement of mesophilic anaerobic digestion.  

PubMed

A combination of bench- and full-scale studies were conducted to determine the effectiveness of high-intensity mechanical shear in an internal recycle loop to enhance mesophilic anaerobic digestion and the implications of this process for routine operations of a digestion system. During short-term batch digestion (56 hours), a 46% increase in biogas production was observed. However, it was found that the degree of digestion enhancement was sludge-specific, with increases in volatile solids destruction ranging from 16.6 to 110%. A full-scale demonstration showed increased total and volatile solids destruction of 22 and 21% for the primary digester and 17.2 and 11% for the secondary digester, respectively. The data also suggest that increased protein degradation is one of the major mechanisms associated with the observed increases in volatile solids destruction. The full-scale demonstration also determined that shear enhanced digestion can be operated without process upset, based on volatile fatty acid profile and headspace biogas composition (methane and carbon dioxide). Dewatering properties, as measured by polymer demand, deteriorated in the primary digester, but there was improvement in the secondary digester. High-intensity shear does not appear to enhance pathogen reduction based on total and fecal coliform bacterial enumeration. PMID:17469661

Muller, Christopher D; Abu-Orf, Mohammad; Novak, John T

2007-03-01

416

Complex between the subtilisin from a mesophilic bacterium and the leech inhibitor eglin-C.  

PubMed

The alkaline proteinase from the mesophilic bacterium Bacillus mesentericus has been crystallized in a 1:1 complex with the inhibitor eglin-C from the medical leech. The crystals have cell dimensions of a = 43.0, b = 71.9, c = 48.3 A and beta = 110.0 degrees and are in the space group P2(1). Three-dimensional data to 2.0 A have been recorded on film from a single crystal. The orientation and position of the complex in the unit cell have been established using the refined coordinates of subtilisin Carlsberg and of eglin-C as independent models. The structure of the complex has been refined by restrained least-squares minimization. The crystallographic R factor (= sigma[magnitude of Fo - magnitude of Fc[/sigma magnitude of Fo) is 15.1% including two Ca2+ ions and 312 water molecules. The structure is discussed in terms of its physicochemical properties in solution and its relation to other Bacillus subtilisins. PMID:1793542

Dauter, Z; Betzel, C; Genov, N; Pipon, N; Wilson, K S

1991-10-01

417

Evaluation of single vs. staged mesophilic anaerobic digestion of kitchen waste with and without microwave pretreatment.  

PubMed

Effects of single and dual stage (acidogenic-methanogenic) mesophilic anaerobic digestion (AD) of kitchen waste (KW) was evaluated at hydraulic retention times (HRTs) of 20, 15, 12 and 9 d with and without thermal microwave (MW) pretreatment (145 °C). Anaerobic acidification in terms of acid accumulation was superior compared to microaerophilic acidification. Maximum anaerobic acidification of KW was determined to occur with an HRT of 2 d which was then selected for the acidification stage. The dual stage AD system fed with untreated KW produced the maximum biogas and volatile solids (VS) stabilization efficiencies at the shortest HRT of 9 d. Conversely, for free liquid resulting from MW pretreatment of KW the two stage reactor at 20 d HRT produced three fold more methane compared with the untreated free liquid control. However, MW pretreatment and AD of the free liquid fraction only, was not a sustainable treatment option. For KW, staging of the AD process had a greater positive impact on waste stabilization and methane yield compared to single stage reactors or MW pretreatment. KW can be characterized as being a readily biodegradable solid waste; concomitantly it is recommended that digester staging without MW pretreatment be employed to maximize methane yield and production. PMID:23648266

Shahriari, Haleh; Warith, Mostafa; Hamoda, Mohamed; Kennedy, Kevin

2013-05-04

418

Financial appraisal of wet mesophilic AD technology as a renewable energy and waste management technology.  

PubMed

Anaerobic digestion (AD) has the potential to support diversion of organic waste from landfill and increase renewable energy production. However, diffusion of this technology has been uneven, with countries such as Germany and Sweden taking the lead, but limited diffusion in other countries such as the UK. In this context, this study explores the financial viability of AD in the UK to offer reasons why it has not been more widely used. This paper presents a model that calculates the Internal Rate of Return (IRR) on a twenty year investment in a 30,000 tonnes per annum wet mesophilic AD plant in the UK for the treatment of source separated organic waste, which is judged to be a suitable technology for the UK climate. The model evaluates the financial significance of the different alternative energy outputs from this AD plant and the resulting economic subsidies paid for renewable energy. Results show that renewable electricity and renewable heat sales supported by renewable electricity and renewable heat tariffs generates the greatest IRR (31.26%). All other uses of biogas generate an IRR in excess of 15%, and are judged to be a financially viable investment. Sensitivity analysis highlights the financial significance of: economic incentive payments and a waste management gate fee; and demonstrates that the fate of the digestate by-product is a source of financial uncertainty for AD investors. PMID:21481437

Dolan, T; Cook, M B; Angus, A J

2011-04-09

419

Anaerobic Degradation of Propionate by a Mesophilic Acetogenic Bacterium in Coculture and Triculture with Different Methanogens  

PubMed Central

A mesophilic acetogenic bacterium (MPOB) oxidized propionate to acetate and CO2 in cocultures with the formate- and hydrogen-utilizing methanogens Methanospirillum hungatei and Methanobacterium formicicum. Propionate oxidation did not occur in cocultures with two Methanobrevibacter strains, which grew only with hydrogen. Tricultures consisting of MPOB, one of the Methanobrevibacter strains, and organisms which are able to convert formate into H2 plus CO2 (Desulfovibrio strain G11 or the homoacetogenic bacterium EE121) also degraded propionate. The MPOB, in the absence of methanogens, was able to couple propionate conversion to fumarate reduction. This propionate conversion was inhibited by hydrogen and by formate. Formate and hydrogen blocked the energetically unfavorable succinate oxidation to fumarate involved in propionate catabolism. Low formate and hydrogen concentrations are required for the syntrophic degradation of propionate by MPOB. In triculture with Methanospirillum hungatei and the aceticlastic Methanothrix soehngenii, propionate was degraded faster than in biculture with Methanospirillum hungatei, indicating that low acetate concentrations are favorable for propionate oxidation as well.

Dong, Xiuzhu; Plugge, Caroline M.; Stams, Alfons J. M.

1994-01-01

420

The Sulfur Oxygenase Reductase from the Mesophilic Bacterium Halothiobacillus neapolitanus Is a Highly Active Thermozyme  

PubMed Central

A biochemical, biophysical, and phylogenetic study of the sulfur oxygenase reductase (SOR) from the mesophilic gammaproteobacterium Halothiobacillus neapolitanus (HnSOR) was performed in order to determine the structural and biochemical properties of the enzyme. SOR proteins from 14 predominantly chemolithoautotrophic bacterial and archaeal species are currently available in public databases. Sequence alignment and phylogenetic analysis showed that they form a coherent protein family. The HnSOR purified from Escherichia coli after heterologous gene expression had a temperature range of activity of 10 to 99°C with an optimum at 80°C (42 U/mg protein). Sulfite, thiosulfate, and hydrogen sulfide were formed at various stoichiometries in a range between pH 5.4 and 11 (optimum pH 8.4). Circular dichroism (CD) spectroscopy and dynamic light scattering showed that the HnSOR adopts secondary and quaternary structures similar to those of the 24-subunit enzyme from the hyperthermophile Acidianus ambivalens (AaSOR). The melting point of the HnSOR was ?20°C lower than that of the AaSOR, when analyzed with CD-monitored thermal unfolding. Homology modeling showed that the secondary structure elements of single subunits are conserved. Subtle changes in the pores of the outer shell and increased flexibility might contribute to activity at low temperature. We concluded that the thermostability was the result of a rigid protein core together with the stabilizing effect of the 24-subunit hollow sphere.

Veith, Andreas; Botelho, Hugo M.; Kindinger, Florian; Gomes, Claudio M.

2012-01-01

421

Methanosarcina as the dominant aceticlastic methanogens during mesophilic anaerobic digestion of putrescible waste.  

PubMed

Taking into account isotope (13)C value a mathematical model was developed to describe the dynamics of methanogenic population during mesophilic anaerobic digestion of putrescible solid waste and waste imitating Chinese municipal solid waste. Three groups of methanogens were considered in the model including unified hydrogenotrophic methanogens and two aceticlastic methanogens Methanosaeta sp. and Methanosarcina sp. It was assumed that Methanosaeta sp. and Methanosarcina sp. are inhibited by high volatile fatty acids concentration. The total organic and inorganic carbon concentrations, methane production, methane and carbon dioxide partial pressures as well as the isotope (13)C incorporation in PSW and CMSW were used for the model calibration and validation. The model showed that in spite of the high initial biomass concentration of Methanosaeta sp. Methanosarcina sp. became the dominant aceticlastic methanogens in the system. This prediction was confirmed by FISH. It is concluded that Methanosarcina sp. forming multicellular aggregates may resist to inhibition by volatile fatty acids (VFAs) because a slow diffusion rate of the acids limits the VFA concentrations inside the Methanosarcina sp. aggregates. PMID:18791805

Vavilin, Vasily A; Qu, Xian; Mazéas, Laurent; Lemunier, Melanie; Duquennoi, Christian; He, Pinjing; Bouchez, Theodore

2008-09-13

422

Denitrification and nitric oxide reduction in an aerobic toluene-treating biofilter  

SciTech Connect

The presence of significant denitrification activity in an aerobic toluene-treating biofilter was demonstrated under batch and flow-through conditions. N{sub 2}O concentrations of 9.2 ppm{sub v} were produced by denitrifying bacteria in the presence of 15% acetylene, in a flow-through system with a bulk gas phase O{sub 2} concentration of >17%. The carbon source for denitrification was not toluene but a byproduct or metabolite of toluene catabolism. Denitrification conditions were successfully used for the reduction of 60 ppm{sub v} nitric oxide to 15 ppm{sub v} at a flow rate of 3 L/min (EBRT of 3 min) in a fully aerated, 17%/v/v O{sub 2} (superficially aerobic) biofilter. Higher NO removal efficiency (97%) was obtained by increasing the toluene supply to the biofilter.

Plessis, C.A. du; Kinney, K.A.; Schroeder, E.D.; Chang, D.P.Y.; Scow, K.M. [Univ. of California, Davis, CA (United States)

1998-05-20

423

Tetrathiobacter kashmirensis gen. nov., sp. nov., a novel mesophilic, neutrophilic, tetrathionate-oxidizing, facultatively chemolithotrophic betaproteobacterium isolated from soil from a temperate orchard in Jammu and Kashmir, India.  

PubMed

Twelve chemolithotrophic strains were isolated from temperate orchard soil on reduced sulfur compounds as energy and electron sources and characterized on the basis of their physiological properties and ability to oxidize various reduced sulfur compounds. The new isolates could oxidize tetrathionate as well as thiosulfate, and oxidation of the latter involved conversion of thiosulfate to tetrathionate followed by its accumulation and eventual oxidation to sulfate, manifested in the production of acid. The mesophilic, neutrophilic, Gram-negative and coccoid bacteria had a respiratory metabolism. Physiologically and biochemically, all the strains were more or less similar, differing only in their growth rates and ability to utilize a few carbon compounds as single heterotrophic substrates. 16S rRNA gene sequence analysis was performed with five representative strains, which revealed a high degree of similarity (> or =99%) among them and placed the cluster in the 'Betaproteobacteria'. The strains showed low levels (93.5-95.3 %) of 16S rRNA gene sequence similarity to Pigmentiphaga kullae, Achromobacter xylosoxidans, Pelistega europaea and species belonging to the genera Alcaligenes, Taylorella and Bordetella. The taxonomic coherence of the new isolates was confirmed by DNA-DNA hybridization. On the basis of their uniformly low 16S rRNA gene sequence similarities to species of all the closest genera, unique fatty acid profile, distinct G+C content (54-55.2 mol%) and phenotypic characteristics that include efficient chemolithotrophic utilization of tetrathionate, the organisms were classified in a new genus, Tetrathiobacter gen. nov. In the absence of any significant discriminatory phenotypic or genotypic characteristics, all the new isolates are considered to constitute a single species, for which the name Tetrathiobacter kashmirensis sp. nov. (type strain WT001(T)=LMG 22695(T)=MTCC 7002(T)) is proposed. PMID:16166666

Ghosh, Wriddhiman; Bagchi, Angshuman; Mandal, Sukhendu; Dam, Bomba; Roy, Pradosh

2005-09-01

424

Methanotrophic Bacteria: Use in Bioremediation  

SciTech Connect

The methanotrophs are aerobic bacteria that oxidize methane as an energy source and carbon source through the enzyme methane monooxygenase (MMO). This MMO can cometabolize or transform nongrowth substrates by either growing or resting cells. Cometabolism is a result of nonspecific MMO activity towards organic compounds that do not serve as carbon or energy sources. While many cometabolizing bacterial species have been identified, the best studied are the methanotrophs. The reason for this is that methanotrophs are ubiquitous and can cometabolize many aliphatic compounds, alkanes, and aromatic compounds. Methanotrophs have been intensely studied for use in degrading chlorinated solvents, most notably trichloroethylene, to environmentally acceptable concentrations in soils, sediment, and groundwater. Stimulation of methanotrophic bacteria is accomplished through the addition of methane and other gaseous nutrients resulting in an increase in contaminant biodegradation and biotransformation. The composition of gaseous nutrients used with methane is dependent on the characteristics of the site geochemistry and microbiology. This biostimulation may be applied in situ within the contaminated aquifer or soil. If necessary, the contaminated soil or groundwater can be moved and treated ex situ based on the site-specific needs.

Brigmon, R.L.

2001-02-15

425

Temperature dependence of nitrate reductase in the psychrophilic unicellular alga Koliella antarctica and the mesophilic alga Chlorella sorokiniana.  

PubMed

Temperature responses of nitrate reductase (NR) were studied in the psychrophilic unicellular alga, Koliella antarctica, and in the mesophilic species, Chlorella sorokiniana. Enzymes from both species were purified to near homogeneity by Blue Sepharose (Pharmacia, Uppsala, Sweden) affinity chromatography and high-resolution anion-exchange chromatography (MonoQ; Pharmacia; Uppsala, Sweden). Both enzymes have a subunit molecular mass of 100 kDa, and K. antarctica NR has a native molecular mass of 367 kDa. NR from K. antarctica used both NADPH and NADH, whereas NR from C. sorokiniana used NADH only. Both NRs used reduced methyl viologen (MVH) or benzyl viologen (BVH). In crude extracts, maximal NADH and MVH-dependent activities of cryophilic NR were found at 15 and 35 degrees C, respectively, and retained 77 and 62% of maximal activity, respectively, at 10 degrees C. Maximal NADH and MVH-dependent activities of mesophilic NR, however, were found at 25 and 45 degrees C, respectively, with only 33 and 23% of maximal activities being retained at 10 degrees C. In presence of 2 microM flavin adenine dinucleotide (FAD), activities of cryophilic NADH:NR and mesophilic NADH:NR were stable up to 25 and 35 degrees C, respectively. Arrhenius plots constructed with cryophilic and mesophilic MVH:NR rate constants, in both presence or absence of FAD, showed break points at 15 and 25 degrees C, respectively. Essentially, similar results were obtained for purified enzymes and for activities measured in crude extracts. Factors by which the rate increases by raising temperature 10 degrees C (Q10) and apparent activation energy (E(a)) values for NADH and MVH activities measured in enzyme preparations without added FAD differed slightly from those measured with FAD. Overall thermal features of the NADH and MVH activities of the cryophilic NR, including optimal temperatures, heat inactivation (with/without added FAD) and break-point temperature in Arrhenius plots, are all shifted by about 10 degrees C towards lower temperatures than those of the mesophilic enzyme. Transfer of electrons from NADH to nitrate occurs via all three redox centres within NR molecule, whereas transfer from MVH requires Mo-pterin prosthetic group only; therefore, our results strongly suggest that structural modification(s) for cold adaptation affect thermodynamic properties of each of the functional domains within NR holoenzyme in equal measure. PMID:17080961

di Rigano, Vittoria Martino; Vona, Vincenza; Lobosco, Ornella; Carillo, Petronia; Lunn, John E; Carfagna, Simona; Esposito, Sergio; Caiazzo, Marianna; Rigano, Carmelo

2006-07-01

426

Growth, natural relationships, cellular fatty acids and metabolic adaptation of sulfate-reducing bacteria that utilize long-chain alkanes under anoxic conditions  

Microsoft Academic Search

Natural relationships, improvement of anaerobic growth on hydrocarbons, and properties that may provide clues to an understanding\\u000a of oxygen-independent alkane metabolism were studied with two mesophilic sulfate-reducing bacteria, strains Hxd3 and Pnd3.\\u000a Strain Hxd3 had been formerly isolated from an oil tank; strain Pnd3 was isolated from marine sediment. Strains Hxd3 and Pnd3\\u000a grew under strictly anoxic conditions on n-alkanes

Frank Aeckersberg; Fred A. Rainey; Friedrich Widdel

1998-01-01

427

Clostridium saccharogumia sp. nov. and Lactonifactor longoviformis gen. nov., sp. nov., two novel human faecal bacteria involved in the conversion of the dietary phytoestrogen secoisolariciresinol diglucoside  

Microsoft Academic Search

Two anaerobic bacteria involved in the conversion of the plant lignan secoisolariciresinol diglucoside were isolated from faeces of a healthy male adult. The first isolate, strain SDG-Mt85-3Db, was a mesophilic strictly anaerobic Gram-positive helically coiled rod. Based on 16S r RNA gene sequence analysis, its nearest relatives were Clostridium cocleatum (96.7% similarity) and Clostridium ramosum (96.6%). In contrast to these

Thomas Clavel; Ramona Lippman; Françoise Gavini; Joël Doré; Michael Blaut

2007-01-01

428

On the Role of Basic Residues in Adapting the Reaction Centre–LH1 Complex for Growth at Elevated Temperatures in Purple Bacteria  

Microsoft Academic Search

The purple photosynthetic bacterium Thermochromatium tepidum is a moderate thermophile, with a growth optimum of 48–50 °C. The X-ray crystal structure of the reaction centre from this organism has been determined, and compared with that from mesophilic bacteria such as Blastochloris viridis and Rhodobacter sphaeroides (Nogi T et al. (2000) Proc Natl Acad Sci USA 97: 13561–13566). Structural features that could

Ashley J. Watson; Arwel V. Hughes; Paul K. Fyfe; Marion C. Wakeham; Kate Holden-Dye; Peter Heathcote; Michael R. Jones

2005-01-01

429

Effects of Cu2+ on morphological structure, functional groups, and elemental composition of aerobic granular sludge.  

PubMed

Aerobic granular sludge (AGS) is shaped by the self-immobilization of microorganisms. In this study, AGS was cultivated successively in a column sequencing batch reactor (SBR) with glucose and sodium acetate as the carbon sources. The shock-loading effects of varying the Cu2+ concentration (0.0, 1.0, 3.0, 5.0, or 10.0 mg/L) on the characteristics of aerobic granules were studied. The results show that Cu2+ has a toxic effect on the aerobic granules. Although the aerobic granules became increasingly loose as the Cu2+ concentration increased from 1.0 to 5.0 mg/L, their structural integrity was largely maintained. However, the aerobic granules disintegrated and their skeletons consisting of internal filamentous bacteria were exposed at the Cu2+ concentration of 10.0mg/L. The functional groups -NH2, -OH, -COOH, and C-N reacted with Cu2+. Ca, Fe, and P were the major trace elements observed in the AGS. With an increase in the Cu2+ concentration from 0.0 to 10.0 mg/L, the weight percentages of the essential elements Fe, Ca, Na, and K in the granules decreased from 23.98%, 24.64%, 3.86%, and 3.87% to 14.90%, 13.93%, 0%, and 0%, respectively, whereas the weight percentage of copper increased correspondingly from 0% to 35.43%. Cu2+ was exchanged with the essential metals and chelated by the nitrogen-containing functional groups (-NH2 or C-N) of the protein. These effects influenced the structural stability of the sludge. PMID:23530333

Zheng, Xiao-Ying; Wang, Xing-Nan; Huang, Xi; Chen, Qing; Chen, Wei; He, Yu-Jie

430

Comparison of the effects of different salts on aerobic ammonia oxidizers for treating ammonium-rich organic wastewater by free and sodium alginate immobilized biomass system  

Microsoft Academic Search

Partial nitrification to nitrite by aerobic ammonium oxidizing bacteria (AOB) is an important pre-treatment step for subsequent denitrification and anammox. Ammonium-rich wastewater may contain different amounts of organic matter and salts, which can influent the growth and activity of AOB significantly. In this study we investigated the influence of various salts on the performance of a partial nitrification process with

Jia Yan; Mike Jetten; Jinlong Rang; Yongyou Hu

2010-01-01

431

Aerobic degradation of phthalic acid by Comamonas acidovoran Fy1 and dimethyl phthalate ester by two reconstituted consortia from sewage sludge at high concentrations  

Microsoft Academic Search

Microbial degradation of phthalic acid (PA) and dimethyl phthalate ester (DMPE) under aerobic conditions was investigated using a pure species of bacteria and two consortia from sewage sludge. Five morphologically distinct microorganisms were obtained in pure culture and identified, and tested for the capability of degrading phthalate and DMPE. Comamonas acidovorans strain Fy-1 showed the highest ability to degrade high

Yingying Wang; Yanzhen Fan; Ji-Dong Gu

2003-01-01

432

Aerobic biological treatment of thermophilically digested sludge.  

PubMed

Aerobic biological treatment of digested sludge was studied in a continuously operated laboratory set-up. An aerated reactor was filled with thermophilically digested sludge from the Moscow wastewater treatment plant and inoculated with special activated sludge. It was then operated at the chemostat mode at different flow rates. Processes of nitrification and denitrification, as well as dephosphatation, occurred simultaneously during biological aerobic treatment of thermophilically digested sludge. Under optimal conditions, organic matter degradation was 9.6%, the concentrations of ammonium nitrogen and phosphate decreased by 89 and 83%, respectively, while COD decreased by 12%. Dewaterability of digested sludge improved significantly. The processes were found to depend on hydraulic retention time, oxygen regime, and temperature. The optimal conditions were as follows: hydraulic retention time 3-4 days, temperature 30-35 degrees C, dissolved oxygen levels 0.2-0.5 mg/L at continuous aeration or 0.7-1 mg/L at intermittent aeration. Based on these findings, we propose a new combined technology of wastewater sludge treatment. The technology combines two stages: anaerobic digestion followed by aerobic biological treatment of digested sludge. The proposed technology makes it possible to degrade the sludge with conversion of approximately 45% volatile suspended solids to biogas, to improve nitrogen and phosphorus removal in reject water from sludge treatment units, and to achieve removal of malodorous substances after 8-9 days of anaerobic-aerobic sludge treatment. PMID:21977658

Kevbrina, M V; Nikolaev, Y A; Danilovich, D A; Vanyushina, A Ya

2011-01-01

433

Aerobic training in brain-injured patients  

Microsoft Academic Search

A pilot study was performed to assess the value of aerobic training as part of the rehabilitation programme for patients with a single incident brain injury requiring admission to an inpatient neurological rehabilitation unit.The cohort consisted of six patients with a combination of impairments including weakness, spasticity, taxia and cognitive problems. Each patient performed an exercise test at the beginning

Roger L Wolman; Catherine Cornall; Kathy Fulcher; Richard Greenwood

1994-01-01

434

Aerobic respiration in pelagic marine sediments  

Microsoft Academic Search

Analyses for dissolved oxygen, nitrate and total CO 2 in the interstitial water have been combined with solid phase sediment analyses of carbon and nitrogen to calculate the rates of reaction and stoichiometry of decomposing organic matter in central Equatorial Pacific pelagic sediments. The diagenesis is dominated by aerobic respiration and nitrification. Organic carbon and total nitrogen decrease exponentially with

Varis Grundmanis; James W. Murray

1982-01-01

435

Aerobic Exercise Prescription for Rheumatoid Arthritics.  

ERIC Educational Resources Information Center

The use of exercise as a general treatment for rheumatoid arthritics (RA) has included range of motion, muscular strength, water exercise and rest therapy while virtually ignoring possible benefits of aerobic exercise. The purposes of this project were to examine the guidelines for exercise prescription in relation to this special population and…

Evans, Blanche W.; Williams, Hilda L.

436

AEROBIC DENITRIFICATION: IMPLICATIONS FOR NITROGEN FATE MODELING  

EPA Science Inventory

In the Mississippi, as well as most nitrogen-degraded rivers and streams, NO3- is the dominant N species and therefore understanding its biogeochemical behavior is critical for accurate nitrogen fate modeling. To our knowledge this is the first work to report aerobic denitrificat...

437

Reflections on Psychotherapy and Aerobic Exercise.  

ERIC Educational Resources Information Center

This document provides a series of reflections by a practicing psychologist on the uses of aerobic workouts in psychotherapy. Two case histories are cited to illustrate the contention that the mode of exercise, rather than simply its presence or absence, is the significant indicator of a patient's emotional well-being or psychopathology. The first…

Silverman, Wade

438

p53, Aerobic Metabolism, and Cancer  

PubMed Central

Abstract p53 regulates the cell cycle and deoxyribonucleic acid (DNA) repair pathways as part of its unequivocally important function to maintain genomic stability. Intriguingly, recent studies show that p53 can also transactivate genes involved in coordinating the two major pathways of energy generation to promote aerobic metabolism, but how this serves to maintain genomic stability is less clear. In an attempt to understand the biology, this review presents human epidemiologic data on the inverse relationship between aerobic capacity and cancer incidence that appears to be mirrored by the impact of p53 on aerobic capacity in mouse models. The review summarizes mechanisms by which p53 regulates mitochondrial respiration and proposes how this might contribute to maintaining genomic stability. Although disparate in nature, the data taken together suggest that the promotion of aerobic metabolism by p53 serves as an important tumor suppressor activity and may provide insights for cancer prevention strategies in the future. Antioxid. Redox Signal. 15, 1739–1748.

Lago, Cory U.; Sung, Ho Joong; Ma, Wenzhe; Wang, Ping-yuan

2011-01-01

439

Aerobic denitrification in various heterotrophic nitrifiers  

Microsoft Academic Search

Various heterotrophic nitrifiers have been tested and found to also be aerobic denitrifiers. The simultaneous use of two electron acceptors (oxygen and nitrate) permits these organisms to grow more rapidly than on either single electron acceptor, but generally results in a lower yield than is obtained on oxygen, alone. One strain, formerly known as “Pseudomonas denitrificans”, was grown in the

L. A. Robertson; R. Cornelisse; P. De Vos; R. Hadioetomo; J. G. Kuenen

1989-01-01

440

The epidemiology of aerobic dance injuries  

Microsoft Academic Search

Aerobic dance is currently the largest organized fitness activity primarily for women in the United States. In an attempt to identify and characterize the health problems associated with it, 351 students and 60 instructors from six facilities were followed for 16 weeks with weekly telephone calls. Of the 327 medical complaints reported during 29,924 hours of documented activity, only 84

James G. Garrick; Donna M. Gillien; Patrice Whiteside

1986-01-01

441

Aerobic Dance Injuries among Instructors and Students.  

ERIC Educational Resources Information Center

|Results of a study of aerobic dance injuries among 800 students and 161 instructors in Japan indicate that most injuries seem to be caused by overuse. Lower leg injuries were most common among instructors, while foot injuries were most common among students. (IAH)|

Mutoh, Yoshiteru; And Others

1988-01-01

442

RBC characteristics for nejayote aerobic treatment  

Microsoft Academic Search

Corn processing effluents, known as nejáyote , were aerobically treated in a lab scale rotating biological contactor. Effluents organic compounds removal was monitored, evaluating them as chemical oxygen demand and reducing sugars. Results showed selective elimination of organic compounds along the cascade by microorganisms, corroborating previous hypothesis on staged removal of maize wastes pollutants by adapted biocommunities.

R. Pedroza de Brenes; C. Durán de Bazúa

1987-01-01

443

Bacterial aerobic synthesis of nanocrystalline magnetite.  

PubMed

The synthesis of iron oxide nanoparticles of the predominantly magnetite phase by the reaction of aqueous iron complexes with the bacterium, Actinobacter spp., is described. This reaction occurs at room temperature and under aerobic conditions, resulting in the formation of superparamagnetic magnetite. PMID:15984833

Bharde, Atul; Wani, Aijaz; Shouche, Yogesh; Joy, Pattayil A; Prasad, Bhagavatula L V; Sastry, Murali

2005-07-01

444

Aerobic treatment of wine-distillery wastewaters  

Microsoft Academic Search

Waste from food-processing and allied industries is largely made up of organic compounds which can be metabolised by aerobic or anaerobic means (Lora and Mir6 1978). However, these wastes present a series of problems to biological deputation plants, such as the need for prior treatment to establish conditions suitable for the development of the microorganisms responsible for the process; and

D. Sales; M. J. Valcárcel; L. Pérez; E. Martinez de la Ossa

1987-01-01

445

Back To Bacteria.  

ERIC Educational Resources Information Center

|Explores new research about bacteria. Discusses bacterial genomes, archaea, unusual environments, evolution, pathogens, bacterial movement, biofilms, bacteria in the body, and a bacterial obsession. Contains 29 references. (JRH)|

Flannery, Maura C.

1997-01-01

446

Monitoring of growth and physiological activities of biofilm during succession on polystyrene from activated sludge under aerobic and anaerobic conditions.  

PubMed

The present research work monitored the successive biofilm development and its catabolic role in the degradation of polystyrene (PS). PS material was artificially colonized with biofilm by incubating it with activated sludge under aerobic and anaerobic conditions. Biofilm formation was monitored by gravimetric weight analysis, spectrophotometric absorbance technique, heterotrophic plate count, and scanning electron microscopy under aerobic and anaerobic conditions. The wet weight (1.59 and 1.17 g) and dry weight (0.41 and 0.08 g) of a biofilm showed a significant constant increase under aerobic and anaerobic conditions, respectively, from first till 9 weeks of incubation. Plate count of the selected bacteria (Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Pseudomonas aeruginosa) considerably declined (90-99 %) in the biofilm after seventh and fifth weeks of incubation under aerobic and anaerobic conditions, respectively, in