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1

Oxygen regulated gene expression in facultatively anaerobic bacteria.  

PubMed

In facultatively anaerobic bacteria such as Escherichia coli, oxygen and other electron acceptors fundamentally influence catabolic and anabolic pathways. E. coli is able to grow aerobically by respiration and in the absence of O2 by anaerobic respiration with nitrate, nitrite, fumarate, dimethylsulfoxide and trimethylamine N-oxide as acceptors or by fermentation. The expression of the various catabolic pathways occurs according to a hierarchy with 3 or 4 levels. Aerobic respiration at the highest level is followed by nitrate respiration (level 2), anaerobic respiration with the other acceptors (level 3) and fermentation. In other bacteria, different regulatory cascades with other underlying principles can be observed. Regulation of anabolism in response to O2 availability is important, too. It is caused by different requirements of cofactors or coenzymes in aerobic and anaerobic metabolism and by the requirement for different O2-independent biosynthetic routes under anoxia. The regulation mainly occurs at the transcriptional level. In E. coli, 4 global regulatory systems are known to be essential for the aerobic/anaerobic switch and the described hierarchy. A two-component sensor/regulator system comprising ArcB (sensor) and ArcA (transcriptional regulator) is responsible for regulation of aerobic metabolism. The FNR protein is a transcriptional sensor-regulator protein which regulates anaerobic respiratory genes in response to O2 availability. The gene activator FhlA regulates fermentative formate and hydrogen metabolism with formate as the inductor. ArcA/B and FNR directly respond to O2, FhlA indirectly by decreased levels of formate in the presence of O2. Regulation of nitrate/nitrite catabolism is effected by two 2-component sensor/regulator systems NarX(Q)/NarL(P) in response to nitrate/nitrite. Co-operation of the different regulatory systems at the target promoters which are in part under dual (or manifold) transcriptional control causes the expression according to the hierarchy. The sensing of the environmental signals by the sensor proteins or domains is not well understood so far. FNR, which acts presumably as a cytoplasmic 'one component' sensor-regulator, is suggested to sense directly cytoplasmic O2-levels corresponding to the environmental O2-levels. PMID:7747938

Unden, G; Becker, S; Bongaerts, J; Schirawski, J; Six, S

1994-01-01

2

Cultivation of Anaerobic and Facultatively Anaerobic Bacteria from Spacecraft-Associated Clean Rooms?  

PubMed Central

In the course of this biodiversity study, the cultivable microbial community of European spacecraft-associated clean rooms and the Herschel Space Observatory located therein were analyzed during routine assembly operations. Here, we focused on microorganisms capable of growing without oxygen. Anaerobes play a significant role in planetary protection considerations since extraterrestrial environments like Mars probably do not provide enough oxygen for fully aerobic microbial growth. A broad assortment of anaerobic media was used in our cultivation strategies, which focused on microorganisms with special metabolic skills. The majority of the isolated strains grew on anaerobic, complex, nutrient-rich media. Autotrophic microorganisms or microbes capable of fixing nitrogen were also cultivated. A broad range of facultatively anaerobic bacteria was detected during this study and also, for the first time, some strictly anaerobic bacteria (Clostridium and Propionibacterium) were isolated from spacecraft-associated clean rooms. The multiassay cultivation approach was the basis for the detection of several bacteria that had not been cultivated from these special environments before and also led to the discovery of two novel microbial species of Pseudomonas and Paenibacillus. PMID:19363082

Stieglmeier, Michaela; Wirth, Reinhard; Kminek, Gerhard; Moissl-Eichinger, Christine

2009-01-01

3

Metabolism of tannin-protein complex by facultatively anaerobic bacteria isolated from koala feces  

Microsoft Academic Search

The metabolic pathways involved in degradation of tannin-protein complex (T-PC) were investigated in various facultatively anaerobic bacteria, with specific reference to fecal isolates from the koala including T-PC-degrading enterobacteria (T-PCDE),Streptococcus bovis, Klebsiella pneumoniae, andK. oxytoca. It was demonstrated that T-PCDE andS. bovis biotype I were capable of degrading protein complexed with gallotannin (a hydrolyzable tannin), but not that complexed with

Ro Osawa; Terry P. Walsh; Steven J. Cork

1993-01-01

4

Characterization of the biochemical-pathway of uranium (VI) reduction in facultative anaerobic bacteria.  

PubMed

Cultures of U(VI) reducing bacteria sourced from abandoned uranium mine tailing dam were evaluated for their ability to reduce U(VI) to U(IV). The species in the cultures reduced U(VI) in solutions with initial U(VI) concentration up to 400mgL(-)(1) under a near neutral pH of 6.5. The electron flow pathway and fate of reduced species was also analysed in the individual species in order to evaluate the potential for control and optimisation of the reduction potential at the biochemical level. The results showed that U(VI) reduction in live cells was completely blocked by the NADH-dehydrogenase inhibitor, rotenone (C23H22O6), and thioredoxin inhibitor, cadmium chloride (CdCl2), showing that U(VI) reduction involves the electron flow through NADH-dehydrogenase, a primary electron donor to the electron transport respiratory (ETR) system. Mass balance analysis of uranium species aided by visual and electron microscopy suggest that most U(VI) reduction occurred on the cell surface of the isolated species. This finding indicates the possibility of easy uranium recovery for beneficial use through biological remediation. Should the U(VI) be reduced inside the cell, recovery would require complete disruption of the cells and therefore would be difficult. The study contributes new knowledge on the underlying mechanisms in the U(VI) reduction in facultative anaerobes. PMID:25065785

Mtimunye, Phalazane J; Chirwa, Evans M N

2014-10-01

5

[Identification of aerobic and facultatively anaerobic sporulating bacteria isolated during the primary milk collection].  

PubMed

Aerobic and/or facultatively anaerobic sporulating Gram-positive bacteria of the genus Bacillus influence nutritive and sensory properties of pasteurized milk by their proteolytic and lipolytic activity. Since particularly raw milk is a source of pasteurized milk contamination by spore-producing bacteria, our investigations were focused on identification of bacilli from operations of milk agricultural primary production. The species B. licheniformis and B. cereus (Crielly et al., 1994) are the most frequently isolated ones in the process of milk production. While B. licheniformis as well as B. subtilis and B. pumilus are mesophilic species, B. cereus is rather psychrotrophic, and as to their health impacts they cause diseases from foods (Griffiths, 1990; Christiansson, 1992; Becker et al., 1994). Sixty-six strains were isolated and identified from operations of milk agricultural primary production (Tab. I). B. licheniformis occurrence (58 strains) was most frequent in the set of samples, followed by B. subtilis (5 strains), B. pumilus (one strain) and B. cereus (one strain), i.e. these are species classified to morphological group I (oval, cell-nonswelling spores). Only one strain Paenibacillus amylolyticus (formerly Bacillus amylolyticus) was isolated from morphological group II (oval, cell-swelling spores). Species representation of isolated strains is in agreement with literacy data (Phillips and Griffiths, 1986; Sutherland and Murdock, 1994; Crielly et al., 1994;). Our results did not confirm the seasonal occurrence (winter-summer) of mesophilic and psychrotrophic bacilli species as reported in literature (McKinnon and Pettipher, 1983; Sutherland and Murdock, 1994; Crielly et al., 1994). Biochemical and physiological characteristics of 66 isolates (Tab. I) are in agreement with literary data (Gordon et al., 1973; Parry et al., 1983; Priest et al., Ash et al., 1993). Strong proteolytic, amylolytic or lipolytic activities of the tested strains could influence the nutritive value of milk as a raw material. Taking into account the dominant representation of bacilli of morphological group I in raw and pasteurized milk (Sutherland and Murdock, 1994; Crielly et al., 1994) their review with basic phenotypic characteristics is shown in Tab. II. As follows from our results mesophilic species from so called "B. subtilis group" (96.9%) were isolated from agricultural primary production of milk most frequently. This is the reason why in addition to B. cereus it is also necessary to identify these species: seven tests shown in Tab III are recommended for their rapid differentiation. PMID:8619278

Pácová, Z; Vyhnálková; Lukásová, J; Holec, J

1996-01-01

6

Aerobic and facultatively anaerobic bacteria associated with the gut of Canada geese (Branta canadensis) and whistling swans (Cygnus columbianus columbianus).  

PubMed

Aerobic and facultatively anaerobic bacteria from the intestinal tracts of swans and geese were isolated and characterized as part of a larger study of the microbiological effects of migratory waterfowl on water quality. A total of 356 isolates were identified by using rapid identification methods and classified by using numerical taxonomy. A diverse population of bacteria was recovered from the waterfowl, and representative strains could be classified into 21 phena. The majority of the aerobic, heterotrophic bacteria found in the gut of the waterfowl were species of Enterobacteriaceae. Streptococcus. Lactobacillus, and Bacillus. Unfortunately, the birds that were examined did not harbor significant numbers of any waterfowl-specific bacterial species. Thus, it may not be possible to assess microbiological impact of migratory waterfowl by using and "indicator" species since avian fecal pollution could not be distinguished from animal and human fecal pollution. PMID:518085

Damaré, J M; Hussong, D; Weiner, R M; Colwell, R R

1979-08-01

7

Aerobic and facultatively anaerobic bacteria associated with the gut of Canada geese (Branta canadensis) and whistling swans (Cygnus columbianus columbianus).  

PubMed Central

Aerobic and facultatively anaerobic bacteria from the intestinal tracts of swans and geese were isolated and characterized as part of a larger study of the microbiological effects of migratory waterfowl on water quality. A total of 356 isolates were identified by using rapid identification methods and classified by using numerical taxonomy. A diverse population of bacteria was recovered from the waterfowl, and representative strains could be classified into 21 phena. The majority of the aerobic, heterotrophic bacteria found in the gut of the waterfowl were species of Enterobacteriaceae. Streptococcus. Lactobacillus, and Bacillus. Unfortunately, the birds that were examined did not harbor significant numbers of any waterfowl-specific bacterial species. Thus, it may not be possible to assess microbiological impact of migratory waterfowl by using and "indicator" species since avian fecal pollution could not be distinguished from animal and human fecal pollution. PMID:518085

Damaré, J M; Hussong, D; Weiner, R M; Colwell, R R

1979-01-01

8

The Paenibacillus polymyxa species is abundant among hydrogen-producing facultative anaerobic bacteria in Lake Averno sediment.  

PubMed

Lake Averno sediment was used to isolate the facultative anaerobic bacteria having the potential for H(2) production. Twenty-five out of 35 isolates recovered from the sediment sample produced hydrogen under anaerobic conditions from glucose with yields ranging from 0.1 to 0.49 mol H(2)/mol glucose. Identification based on 16S rRNA gene sequence analysis revealed that most of them belong to the Firmicutes group, with a prevalence of the Paenibacillus polymyxa species. Seven distinct genomic fingerprints among the 11 P. polymyxa isolates were obtained using the random amplified polymorphic DNA (RAPD) technique. Glucose fermentation by P. polymyxa isolates was investigated. Glucose was totally consumed after 3 days of fermentation. The fermentation products were hydrogen (0.18-0.47 mol H(2)/mol glucose), ethanol (0.1-0.5 mol ethanol/mol glucose), and 2,3-butanediol (0.1 mol 2,3-butanediol/mol glucose). Lower amounts of acetic, butyric, formic, lactic, and propionic acids were detected. All metabolic data concerning P. polymyxa isolates were analyzed by cluster analysis to reveal similarities and/or differences with clustering based on RAPD profiles. Despite the high metabolic similarity among almost all P. paenibacillus isolates, results of cluster analyses of metabolic and genetic data do not match completely. PMID:22038026

Lal, Sadhana; Romano, Stefano; Chiarini, Luigi; Signorini, Antonella; Tabacchioni, Silvia

2012-05-01

9

Isolation and characterization of two novel ethanol-tolerant facultative-anaerobic thermophilic bacteria strains from waste compost.  

PubMed

In a search for potential ethanologens, waste compost was screened for ethanol-tolerant thermophilic microorganisms. Two thermophilic bacterial strains, M5EXG and M10EXG, with tolerance of 5 and 10% (v/v) ethanol, respectively, were isolated. Both isolates are facultative anaerobic, non-spore forming, non-motile, catalase-positive, oxidase-negative, Gram-negative rods that are capable of utilizing a range of carbon sources including arabinose, galactose, mannose, glucose and xylose and produce low amounts of ethanol, acetate and lactate. Growth of both isolates was observed in fully defined minimal media within the temperature range 50-80 degrees C and pH 6.0-8.0. Phylogenetic analysis of the 16S rDNA sequences revealed that both isolates clustered with members of subgroup 5 of the genus Bacillus. G+C contents and DNA-DNA relatedness of M5EXG and M10EXG revealed that they are strains belonging to Geobacillus thermoglucosidasius. However, physiological and biochemical differences were evident when isolates M5EXG and M10EXG were compared with G. thermoglucosidasius type strain (DSM 2542(T)). The new thermophilic, ethanol-tolerant strains of G. thermoglucosidasius may be candidates for ethanol production at elevated temperatures. PMID:16532362

Fong, Jiunn C N; Svenson, Charles J; Nakasugi, Kenlee; Leong, Caine T C; Bowman, John P; Chen, Betty; Glenn, Dianne R; Neilan, Brett A; Rogers, Peter L

2006-10-01

10

Carotenoid pigments of facultatively anaerobic spirochetes.  

PubMed

Carotenoid pigments were purified from a previously undescribed, red, halophilic spirochete (spirochete RS1), and from Spirochaeta aurantia strain J1. Both spirochetes are facultative anaerobes and produce pigments when growing aerobically. The major pigments of the two spirochetes were identified by means of chromatographic analysis, absorption spectroscopy, hydride reduction, acetylation and silylation experiments, and mass spectrometry. It was concluded that the major pigment from spirochete RS1 was 4-keto-1',2'-dihydro-1'-hydroxytorulene. This conclusion was further supported by infrared spectroscopy and additional analytical data. The evidence showed that the major pigment from S. aurantia was 1',2'-dihydro-1'-hydroxytorulene. Chromatographic and spectrophotometric evidence indicated that this pigment was also present, as a minor carotenoid component, in spirochete RS1. These pigments have been previously detected almost exclusively in gliding bacteria, such as species of Flexibacter, Stigmatella, and Myxococcus. The occurrence of 4-keto-1',2'-dihydro-1'-hydroxytorulene and 1',2'-dihydro-1'-hydroxytorulene in both spirochetes and gliding bacteria may have significance with respect to the evolutionary development of these organisms. PMID:1158846

Greenberg, E P; Canale-Parola, E

1975-09-01

11

Aerobic andFacultatively Anaerobic Bacteria Associated with theGutofCanadaGeese(Branta canadensis) andWhistling Swans(Cygnus columbianus columbianus)  

Microsoft Academic Search

Aerobic andfacultatively anaerobic bacteria fromtheintestinal tracts ofswans andgeesewereisolated andcharacterized aspartofa larger studyofthe microbiological effects ofmigratory waterfowl onwaterquality. A total of356 isolates wereidentified byusing rapididentification methodsandclassified by using numerical taxonomy. A diverse population ofbacteria wasrecovered from thewaterfowl, andrepresentative strains couldbeclassified into21phena. The majority oftheaerobic, heterotrophic bacteria foundinthegutofthewaterfowl werespecies ofEnterobacteriaceae, Streptococcus, Lactobacillus, andBacillus. Unfortunately, thebirds thatwereexamined didnotharborsignificant numbers ofanywaterfowl-specific bacterial species. Thus,itmaynotbepossible

J. M. DAMARE; R. M. WEINER; R. R. COLWELL

1979-01-01

12

Assessment of antimicrobial effect of Biosilicate® against anaerobic, microaerophilic and facultative anaerobic microorganisms.  

PubMed

This study assessed the antimicrobial activity of a new bioactive glass-ceramic (Biosilicate®) against anaerobic, microaerophilic, and facultative anaerobic microorganisms. Evaluation of the antimicrobial activity was carried out by three methods, namely agar diffusion, direct contact, and minimal inhibitory concentration (MIC). For the agar diffusion technique, bio glass-ceramic activity was observed against various microorganisms, with inhibition haloes ranging from 9.0 ± 1.0 to 22.3 ± 2.1 mm. For the direct contact technique, Biosilicate® displayed activity against all the microorganisms, except for S. aureus. In the first 10 min of contact between the microorganisms and Biosilicate®, there was a drastic reduction in the number of viable cells. Confirming the latter results, MIC showed that the Biosilicate® inhibited the growth of microorganisms, with variations between ? 2.5 and 20 mg/ml. The lowest MIC values (7.5 to ? 2.5 mg/ml) were obtained for oral microorganisms. In conclusion, Biosilicate® exhibits a wide spectrum of antimicrobial properties, including anaerobic bacteria. PMID:21556979

Martins, Carlos Henrique Gomes; Carvalho, Tatiane Cruz; Souza, Maria Gorete Mendes; Ravagnani, Christian; Peitl, Oscar; Zanotto, Edgar Dutra; Panzeri, Heitor; Casemiro, Luciana Assirati

2011-06-01

13

Pathogenicity of Propionibacterium acnes in mixed infections with facultative bacteria  

Microsoft Academic Search

Summary. Single and mixed infections with 11 clinical isolates of Propionibacterium acnes and three facultative bacteria (Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae) were studied in a subcutaneous abscess model in mice. Abscesses were induced by pure cultures of six of 11 strains of P. acnes and by the three facultative bacteria. The abscesses produced by each of the six

I. Brook

1991-01-01

14

Spirochaeta aurantia, a pigmented, facultatively anaerobic spirochete.  

PubMed

A strain of Spirochaeta aurantia was isolated from mud by a procedure involving migration of the organisms through cellulose ester filter discs (0.3-mum pore diameter) onto the surface of culture plates. The helical cells measured 0.3 by 10 to 20 mum during exponential growth. Electron microscopy showed the presence of two subterminally inserted axial fibrils partially overlapping in a 1-2-1 arrangement. An outer envelope, exhibiting a polygonal substructure, was observed. The spirochete grew either aerobically or anaerobically, with aerobic yields of 9.8 x 10(8) cells per ml and anaerobic yields of 3.0 x 10(8) cells per ml. The organism used carbohydrates, but not amino acids, as energy sources. Amino acids served as sole nitrogen sources, whereas inorganic ammonium salts did not. The presence of biotin and thiamine in the medium was required for growth. Growing cells fermented maltose mainly to carbon dioxide, hydrogen, ethyl alcohol, and acetic acid. Small amounts of formic and lactic acids, acetoin, and diacetyl were produced. Cells of S. aurantia growing aerobically produced a yellow-orange pigment. Chemical analysis indicated that the pigment was carotenoid in nature, its main component being lycopene or a similar compound. S. aurantia is not closely related to the leptospires, since it lacks both the hemolytic antigen and the hooked ends typical of the latter organisms. Furthermore, the guanine plus cytosine content in the deoxyribonucleic acid of S. aurantia (66.8 moles%) differs drastically from that of leptospires. PMID:5764339

Breznak, J A; Canale-Parola, E

1969-01-01

15

Acidithiobacillus ferrivorans , sp. nov.; facultatively anaerobic, psychrotolerant iron-, and sulfur-oxidizing acidophiles isolated from metal mine-impacted environments  

Microsoft Academic Search

Phenotypic and genotypic analysis was carried out on four iron- and sulfur-oxidizing acidophilic bacteria (the “NO-37 group”)\\u000a isolated from different parts of the world. 16S rRNA phylogeny showed that they are highly related to each other, but are\\u000a less related to the type strain of Acidithiobacillus ferrooxidans. The NO-37 group isolates are obligate chemolithoautotrophs, facultative anaerobes, diazotrophic, and psychrotolerant. They

Kevin B. Hallberg; Elena González-Toril; D. Barrie Johnson

2010-01-01

16

Anaerobic bacteria as producers of antibiotics.  

PubMed

Anaerobic bacteria are the oldest terrestrial creatures. They occur ubiquitously in soil and in the intestine of higher organisms and play a major role in human health, ecology, and industry. However, until lately no antibiotic or any other secondary metabolite has been known from anaerobes. Mining the genome sequences of Clostridium spp. has revealed a high prevalence of putative biosynthesis genes (PKS and NRPS), and only recently the first antibiotic from the anaerobic world, closthioamide, has been isolated from the cellulose degrading bacterium Clostridium cellulolyticum. The successful genetic induction of antibiotic biosynthesis in an anaerobe encourages further investigations of obligate anaerobes to tap their hidden biosynthetic potential. PMID:22854892

Behnken, Swantje; Hertweck, Christian

2012-10-01

17

D/H fractionation in lipids of facultative and obligate denitrifying and sulfate reducing bacteria  

NASA Astrophysics Data System (ADS)

The hydrogen isotopic composition of lipids has been shown to vary broadly in both cultured bacteria and in environmental samples. Culturing studies have indicated that this variability may primarily reflect metabolism; however, the limited number of organisms studied thus far prevents application of these trends to interpretation of environmental samples. Here we report D/H fractionations in anaerobic bacteria, including both facultative and obligate anaerobic organisms with a range of electron donors, acceptors, and metabolic pathways. Experiments using the metabolically flexible alphaproteobacterium Paracoccus denitrificans probe particular central metabolic pathways using a range of terminal electron acceptors. While a large range of ?D values has been observed during aerobic metabolism, denitrifying cultures produce a more limited range in ?D values that are more similar to each other than the corresponding aerobic culture. Data from the sulfate reducing bacteria Desulfobacterium autotrophicum and Desulfobacter hydrogenophilus indicate that chemolithoautotrophy and anaerobic heterotrophy can produce similar ?D values, and are similar between bacteria despite differing metabolic pathways. These results suggest that the fractionation of D/H depends both on the specific metabolic pathway and the electron acceptor. While this is not inconsistent with previous studies, it suggests the simple correspondence between ?D and metabolism previously understood from aerobic bacteria is not universally applicable.

Osburn, M. R.; Sessions, A. L.

2012-12-01

18

Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan  

PubMed Central

Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

2014-01-01

19

Culturable aerobic and facultative bacteria from the gut of the polyphagic dung beetle Thorectes lusitanicus.  

PubMed

Unlike other dung beetles, the Iberian geotrupid, Thorectes lusitanicus, exhibits polyphagous behavior; for example, it is able to eat acorns, fungi, fruits, and carrion in addition to the dung of different mammals. This adaptation to digest a wider diet has physiological and developmental advantages and requires key changes in the composition and diversity of the beetle's gut microbiota. In this study, we isolated aerobic, facultative anaerobic, and aerotolerant microbiota amenable to grow in culture from the gut contents of T. lusitanicus and resolved isolate identity to the species level by sequencing 16S rRNA gene fragments. Using BLAST similarity searches and maximum likelihood phylogenetic analyses, we were able to reveal that the analyzed fraction (culturable, aerobic, facultative anaerobic, and aerotolerant) of beetle gut microbiota is dominated by the phyla Proteobacteria, Firmicutes, and Actinobacteria. Among Proteobacteria, members of the order Enterobacteriales (Gammaproteobacteria) were the most abundant. The main functions associated with the bacteria found in the gut of T. lusitanicus would likely include nitrogen fixation, denitrification, detoxification, and diverse defensive roles against pathogens. PMID:24339348

Hernández, Noemi; Escudero, José A; Millán, Álvaro San; González-Zorn, Bruno; Lobo, Jorge M; Verdú, José R; Suárez, Mónica

2015-04-01

20

The Aerobic and Anaerobic Microbiology of Pustular Acne Lesions  

Microsoft Academic Search

Specimens from 32 pustular acne lesions that were inoculated on media supportive for the growth of aerobic and anaerobic bacteria showed bacterial growth. Only aerobic or facultative bacteria were recovered in 15 (47%) specimens, only anaerobic bacteria in 11 (34%) specimens, and mixed aerobic and anaerobic bacteria in 6 (18%) specimens. A total of 57 isolates, 31 anaerobes (1.0 per

Itzhak Brook; Edith H. Frazier; Michael E. Cox; Josef K. Yeager

1995-01-01

21

Growth of the facultative anaerobe Shewanella putrefaciens by elemental sulfur reduction  

NASA Technical Reports Server (NTRS)

The growth of bacteria by dissimilatory elemental sulfur reduction is generally associated with obligate anaerobes and thermophiles in particular. Here we describe the sulfur-dependent growth of the facultatively anaerobic mesophile Shewanella putrefaciens. Six of nine representative S. putrefaciens isolates from a variety of environments proved able to grow by sulfur reduction, and strain MR-1 was chosen for further study. Growth was monitored in a minimal medium (usually with 0.05% Casamino Acids added as a growth stimulant) containing 30 mM lactate and limiting concentrations of elemental sulfur. When mechanisms were provided for the removal of the metabolic end product, H2S, measurable growth was obtained at sulfur concentrations of from 2 to 30 mM. Initial doubling times were ca. 1.5 h and substrate independent over the range of sulfur concentrations tested. In the cultures with the highest sulfur concentrations, cell numbers increased by greater than 400-fold after 48 h, reaching a maximum density of 6.8 x 10(8) cells ml-1. Yields were determined as total cell carbon and ranged from 1.7 to 5.9 g of C mol of S(0) consumed-1 in the presence of the amino acid supplement and from 0.9 to 3.4 g of C mol of S(0-1) in its absence. Several lines of evidence indicate that cell-to-sulfur contact is not required for growth. Approaches for the culture of sulfur-metabolizing bacteria and potential ecological implications of sulfur reduction in Shewanella-like heterotrophs are discussed.

Moser, D. P.; Nealson, K. H.

1996-01-01

22

Growth of the facultative anaerobe Shewanella putrefaciens by elemental sulfur reduction.  

PubMed Central

The growth of bacteria by dissimilatory elemental sulfur reduction is generally associated with obligate anaerobes and thermophiles in particular. Here we describe the sulfur-dependent growth of the facultatively anaerobic mesophile Shewanella putrefaciens. Six of nine representative S. putrefaciens isolates from a variety of environments proved able to grow by sulfur reduction, and strain MR-1 was chosen for further study. Growth was monitored in a minimal medium (usually with 0.05% Casamino Acids added as a growth stimulant) containing 30 mM lactate and limiting concentrations of elemental sulfur. When mechanisms were provided for the removal of the metabolic end product, H2S, measurable growth was obtained at sulfur concentrations of from 2 to 30 mM. Initial doubling times were ca. 1.5 h and substrate independent over the range of sulfur concentrations tested. In the cultures with the highest sulfur concentrations, cell numbers increased by greater than 400-fold after 48 h, reaching a maximum density of 6.8 x 10(8) cells ml-1. Yields were determined as total cell carbon and ranged from 1.7 to 5.9 g of C mol of S(0) consumed-1 in the presence of the amino acid supplement and from 0.9 to 3.4 g of C mol of S(0-1) in its absence. Several lines of evidence indicate that cell-to-sulfur contact is not required for growth. Approaches for the culture of sulfur-metabolizing bacteria and potential ecological implications of sulfur reduction in Shewanella-like heterotrophs are discussed. PMID:11536738

Moser, D P; Nealson, K H

1996-01-01

23

Genome Sequence of a Promising Hydrogen-Producing Facultative Anaerobic Bacterium, Brevundimonas naejangsanensis Strain B1  

PubMed Central

Brevundimonas naejangsanensis strain B1 is a newly isolated, facultative anaerobic bacterium capable of producing hydrogen with high efficiency. Here, we present a 2.94-Mb assembly of the genome sequence of strain B1, which may provide further insights into the molecular mechanism of hydrogen production from bioresource. PMID:24903872

Zhang, Ting; Bao, Meidan; Jiang, Yixin; Wang, Yu; Tan, Tianwei

2014-01-01

24

Differential Susceptibility of Bacteria to Mouse Paneth Cell ?-Defensins under Anaerobic Conditions.  

PubMed

Small intestinal Paneth cells secrete ?-defensin peptides, termed cryptdins (Crps) in mice, into the intestinal lumen, where they confer immunity to oral infections and define the composition of the ileal microbiota. In these studies, facultative bacteria maintained under aerobic or anaerobic conditions displayed differential sensitivities to mouse ?-defensins under in vitro assay conditions. Regardless of oxygenation, Crps 2 and 3 had robust and similar bactericidal activities against S. Typhimurium and S. flexneri, but Crp4 activity against S. flexneri was attenuated in the absence of oxygen. Anaerobic bacteria varied in their susceptibility to Crps 2-4, with Crp4 showing less activity than Crps 2 and 3 against Enterococcus faecalis, and Bacteroides fragilis in anaerobic assays, but Fusobacterium necrophorum was killed only by Crp4 and not by Crps 2 and 3. The influence of anaerobiosis in modulating Crp bactericidal activities in vitro suggests that ?-defensin effects on the enteric microbiota may be subject to regulation by local oxygen tension. PMID:25383215

Mastroianni, Jennifer R; Lu, Wuyuan; Selsted, Michael E; Ouellette, André J

2014-01-01

25

Differential Susceptibility of Bacteria to Mouse Paneth Cell ?-Defensins under Anaerobic Conditions  

PubMed Central

Small intestinal Paneth cells secrete ?-defensin peptides, termed cryptdins (Crps) in mice, into the intestinal lumen, where they confer immunity to oral infections and define the composition of the ileal microbiota. In these studies, facultative bacteria maintained under aerobic or anaerobic conditions displayed differential sensitivities to mouse ?-defensins under in vitro assay conditions. Regardless of oxygenation, Crps 2 and 3 had robust and similar bactericidal activities against S. Typhimurium and S. flexneri, but Crp4 activity against S. flexneri was attenuated in the absence of oxygen. Anaerobic bacteria varied in their susceptibility to Crps 2–4, with Crp4 showing less activity than Crps 2 and 3 against Enterococcus faecalis, and Bacteroides fragilis in anaerobic assays, but Fusobacterium necrophorum was killed only by Crp4 and not by Crps 2 and 3. The influence of anaerobiosis in modulating Crp bactericidal activities in vitro suggests that ?-defensin effects on the enteric microbiota may be subject to regulation by local oxygen tension. PMID:25383215

Mastroianni, Jennifer R.; Lu, Wuyuan; Selsted, Michael E.; Ouellette, André J.

2014-01-01

26

The place of molecular genetic methods in the diagnostics of human pathogenic anaerobic bacteria. A minireview.  

PubMed

Anaerobic infections are common and can cause diseases associated with severe morbidity, but are easily overlooked in clinical settings. Both the relatively small number of infections due to exogenous anaerobes and the much larger number of infections involving anaerobic species that are originally members of the normal flora, may lead to a life-threatening situation unless appropriate treatment is instituted. Special laboratory procedures are needed for the isolation, identification and susceptibility testing of this diverse group of bacteria. Since many anaerobes grow more slowly than the facultative or aerobic bacteria, and particularly since clinical specimens yielding anaerobic bacteria commonly contain several organisms and often very complex mixtures of aerobic and anaerobic bacteria, considerable time may elapse before the laboratory is able to provide a final report. Species definition based on phenotypic features is often time-consuming and is not always easy to carry out. Molecular genetic methods may help in the everyday clinical microbiological practice in laboratories dealing with the diagnostics of anaerobic infections. Methods have been introduced for species diagnostics, such as 16S rRNA PCR-RFLP profile determination, which can help to distinguish species of Bacteroides, Prevotella, Actinomyces, etc. that are otherwise difficult to differentiate. The use of DNA-DNA hybridization and the sequencing of special regions of the 16S rRNA have revealed fundamental taxonomic changes among anaerobic bacteria. Some anaerobic bacteria are extremely slow growing or not cultivatable at all. To detect them in special infections involving flora changes due to oral malignancy or periodontitis, for instance, a PCR-based hybridization technique is used. Molecular methods have demonstrated the spread of specific resistance genes among the most important anaerobic bacteria, the members of the Bacteroides genus. Their detection and investigation of the IS elements involved in their expression may facilitate following of the spread of antibiotic resistance among anaerobic bacteria involved in infections and in the normal flora members. Molecular methods (a search for toxin genes and ribotyping) may promote a better understanding of the pathogenic features of some anaerobic infections, such as the nosocomial diarrhoea caused by C. difficile and its spread in the hospital environment and the community. The investigation of toxin production at a molecular level helps in the detection of new toxin types. This mini-review surveys some of the results obtained by our group and others using molecular genetic methods in anaerobic diagnostics. PMID:16956128

Nagy, Elisabeth; Urbán, Edit; Sóki, J; Terhes, Gabriella; Nagy, Katalin

2006-06-01

27

Dissimilatory Metal Reduction by the Facultative Anaerobe Pantoea agglomerans SP1  

PubMed Central

Anaerobic enrichments with acetate as the electron donor and Fe(III) as the terminal electron acceptor were obtained from sediments of Salt Pond, a coastal marine basin near Woods Hole, Mass. A pure culture of a facultatively anaerobic Fe(III) reducer was isolated, and 16S rRNA analysis demonstrated that this organism was most closely related to Pantoea (formerly Enterobacter) agglomerans, a member of the family Enterobacteriaceae within the gamma subdivision of the Proteobacteria. This organism, designated strain SP1, can grow by coupling the oxidation of acetate or H2 to the reduction of a variety of electron acceptors, including Fe(III), Mn(IV), Cr(VI), and the humic substance analog 2,6-anthraquinone disulfonate, but not sulfate. To our knowledge, this is the first mesophilic facultative anaerobe reported to couple acetate oxidation to dissimilatory metal reduction. PMID:10653716

Francis, Chris A.; Obraztsova, Anna Y.; Tebo, Bradley M.

2000-01-01

28

Tolerance of Anaerobic Bacteria to Chlorinated Solvents  

PubMed Central

The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation. PMID:24441515

Koenig, Joanna C.; Groissmeier, Kathrin D.; Manefield, Mike J.

2014-01-01

29

Antimicrobial activity of metronidazole in anaerobic bacteria.  

PubMed

The antimicrobial activity of metronidazole was investigated in anaerobic bacteria by use of time-viability studies. This antimicrobial agent has a rapid onset of bactericidal activity under proper reducing conditions. The bactericidal rates were not affected by inoculum size or nutritional requirements, nor by inhibition of growth and protein synthesis by chloramphenicol. Using supernatant fractions of actively growing cultures of susceptible organisms, we observed a disappearance of metronidazole and a loss of biological activity, but there was no significant change in preparations from resistant bacteria. The decrease in drug concentration with susceptible cells occurred during the time that its bactericidal action was being exerted. Extracts from susceptible organisms rapidly reduced the concentration of metronidazole, confirming previous observations which suggest that the drug acts as a terminal electron acceptor. Radioisotope experiments with [14C]metronidazole revealed that the compound was taken up by both resistant and susceptible bacteria, although there was a difference in rate and extent of accumulation. These studies demonstrate that metronidazole's antimicrobial activity against anaerobic bacteria is bactericidal and independent of growth rate, and that it involves the uptake and metabolism of the compound. PMID:233729

Tally, F P; Goldin, B R; Sullivan, N; Johnston, J; Gorbach, S L

1978-03-01

30

Draft Genome Sequence of Amphibacillus jilinensis Y1T, a Facultatively Anaerobic, Alkaliphilic and Halotolerant Bacterium  

PubMed Central

The genus Amphibacillus was established in 1990, and seven additional species were described in the past two decades. Amphibacillus jilinensis Y1T is a facultatively anaerobic and alkaliphilic bacterium isolated from a soda lake in China. Here we describe the structural and genetic features of the draft genome about the type strain Y1T (3,831,075 bp, with a G+C content of 37.27%). This is the first genome report of the Amphibacillus genus. PMID:24501633

Cheng, Hong; Fang, Ming-Xu; Jiang, Xia-Wei; Wu, Min; Zhu, Xu-Fen; Zheng, Gang; Yang, Zhi-Jian

2013-01-01

31

Anaerobic utilization of aromatic carboxylates by bacteria  

SciTech Connect

Very large quantities of compounds containing aromatic nuclei are produced annually from natural and industrial sources. A substantial portion of these materials accumulates in anaerobic environments, and since some of these are known or potential carcinogens, there has been growing interest in understanding how aromatics are degraded in the absence of molecular oxygen, an essential substrate in the aerobic catabolism of benzene rings. The microbiology and biochemistry involved in the degradation of natural products, mostly those derived from lignin, is considered in this chapter, with special emphasis on the role and contribution of studies with phototrophic bacteria to current understanding of these processes.

Gibson, J.; Harwood, C.S.

1996-03-25

32

Toxicity of organic extraction reagents to anaerobic bacteria  

SciTech Connect

Thirty organic chemicals were examined by means of a small scale (60 mL) batch fermentation bioassay procedure for their toxicity to a commercial inoculum (Methanobac, W.B.E. Ltd.), which was a mixed culture of facultatively anaerobic, acid-producing bacteria. Gas production, pH change of medium, and the concentrations of ethanol, VFA, and lactic acid were measured after 75 h growth. The optimum experimental conditions for toxicity testing were alfalfa as substrate (2 g), a buffered nutrient medium (pH 6.8), ''Methanobac'' inoculum (10 mL), and test chemicals at levels between 10 and 100 ..mu..L/mL. Thirteen chemicals were nontoxic, and included the paraffins (C/sub 6/-C/sub 12/), phthalates, organophosphorus compounds, Freon 113 (1,1,2-trichloro-1,2,2-trifluoro ethane), Aliquat 336 (tricaprylylmethyl ammonium chloride), di-isoamyl ether, and trioctylamine. Other amine extractants were partially toxic. Alcohols (C/sub 5/-C/sub 12/), ketones (C/sub 5/-C/sub 8/), benzene derivatives, isoamyl acetate, and di-isopropyl ether were toxic. Generally, the chemicals were not toxic unless present at levels in excess of that expected to be required to saturate the aqueous phase. Total gas production was a good indicator of toxicity even within 24 h, but the presence of homofermentative (nongas producing) lactic acid bacteria complicated interpretation. ''Methanobac'' inoculum was compared with an inoculum derived from a rumen culture for four test chemicals. The results were essentially the same. However, the toxicity of a chemical to bacteria is likely to vary considerably between bacterial species.

Playne, M.J.; Smith, B.R.

1983-05-01

33

Genomic Analysis of Melioribacter roseus, Facultatively Anaerobic Organotrophic Bacterium Representing a Novel Deep Lineage within Bacteriodetes/Chlorobi Group  

PubMed Central

Melioribacter roseus is a moderately thermophilic facultatively anaerobic organotrophic bacterium representing a novel deep branch within Bacteriodetes/Chlorobi group. To better understand the metabolic capabilities and possible ecological functions of M. roseus and get insights into the evolutionary history of this bacterial lineage, we sequenced the genome of the type strain P3M-2T. A total of 2838 open reading frames was predicted from its 3.30 Mb genome. The whole proteome analysis supported phylum-level classification of M. roseus since most of the predicted proteins had closest matches in Bacteriodetes, Proteobacteria, Chlorobi, Firmicutes and deeply-branching bacterium Caldithrix abyssi, rather than in one particular phylum. Consistent with the ability of the bacterium to grow on complex carbohydrates, the genome analysis revealed more than one hundred glycoside hydrolases, glycoside transferases, polysaccharide lyases and carbohydrate esterases. The reconstructed central metabolism revealed pathways enabling the fermentation of complex organic substrates, as well as their complete oxidation through aerobic and anaerobic respiration. Genes encoding the photosynthetic and nitrogen-fixation machinery of green sulfur bacteria, as well as key enzymes of autotrophic carbon fixation pathways, were not identified. The M. roseus genome supports its affiliation to a novel phylum Ignavibateriae, representing the first step on the evolutionary pathway from heterotrophic ancestors of Bacteriodetes/Chlorobi group towards anaerobic photoautotrophic Chlorobi. PMID:23301019

Kadnikov, Vitaly V.; Mardanov, Andrey V.; Podosokorskaya, Olga A.; Gavrilov, Sergey N.; Kublanov, Ilya V.; Beletsky, Alexey V.; Bonch-Osmolovskaya, Elizaveta A.; Ravin, Nikolai V.

2013-01-01

34

Susceptibility of strict and facultative anaerobes Isolated from endodontic infections to metronidazole and beta-lactams.  

PubMed

Endodontic infections are mixed aerobic-anaerobic infections and several microbial groups associated to these pathologies are also involved in orofacial infections. The goal of this study was to evaluate the susceptibility of microorganisms isolated from endodontic infections to beta-lactams and metronidazole and verify the production of beta-lactamases. Clinical specimens were collected from 58 endodontic infections of 52 patients. The microorganisms were isolated in selective and non-selective culture media, under anaerobiosis and aerobiosis, and identified using biochemical methods. In the susceptibility tests, it was used an agar dilution method, and Wilkins-Chalgren agar enriched with blood, hemin and menadione for the anaerobes, while Mueller-Hinton agar was employed for the facultative anaerobes. The production of beta-lactamases was evaluated through the biological and chromogenic cephalosporin methods. All tested isolates were sensitive to imipenem and 99.3% to amoxicillin/clavulanate association, while 16.1% showed resistance to amoxicillin and penicillin G, and 4.89% to cefoxitin. Resistance to metronidazole was just found in facultative anaerobes. Production of beta-lactamases was detected in 18.2% of the isolates and presented a correlation with resistance to beta-lactams. PMID:19089195

Gaetti-Jardim Júnior, Elerson; Landucci, Luís Fernando; Lins, Samira Ambar; Vieira, Evanice Menezes Marçal; de Oliveira, Sérgio Ricardo

2007-12-01

35

SUSCEPTIBILITY OF STRICT AND FACULTATIVE ANAEROBES ISOLATED FROM ENDODONTIC INFECTIONS TO METRONIDAZOLE AND ?-LACTAMS  

PubMed Central

Endodontic infections are mixed aerobic-anaerobic infections and several microbial groups associated to these pathologies are also involved in orofacial infections. The goal of this study was to evaluate the susceptibility of microorganisms isolated from endodontic infections to ?-lactams and metronidazole and verify the production of ?-lactamases. Clinical specimens were collected from 58 endodontic infections of 52 patients. The microorganisms were isolated in selective and non-selective culture media, under anaerobiosis and aerobiosis, and identified using biochemical methods. In the susceptibility tests, it was used an agar dilution method, and Wilkins-Chalgren agar enriched with blood, hemin and menadione for the anaerobes, while Mueller- Hinton agar was employed for the facultative anaerobes. The production of ?-lactamases was evaluated through the biological and chromogenic cephalosporin methods. All tested isolates were sensitive to imipenem and 99.3% to amoxicillin/clavulanate association, while 16.1% showed resistance to amoxicillin and penicillin G, and 4.89% to cefoxitin. Resistance to metronidazole was just found in facultative anaerobes. Production of ?-lactamases was detected in 18.2% of the isolates and presented a correlation with resistance to ?-lactams. PMID:19089195

Gaetti-Jardim, Elerson; Landucci, Luís Fernando; Lins, Samira Âmbar; Vieira, Evanice Menezes Marçal; de Oliveira, Sérgio Ricardo

2007-01-01

36

Fermentative and oxidative transformation of ferulate by a facultatively anaerobic bacterium isolated from sewage sludge.  

PubMed Central

A facultatively anaerobic, gram-negative, non-sporeforming, motile rod-shaped bacterium was isolated from methanogenic consortia degrading 3-methoxy-4-hydroxycinnamate (ferulate). Consortia were originally enriched from a laboratory anaerobic digester fed sewage sludge. In the absence of exogenous electron acceptors and with the addition of 0.1% yeast extract, the isolated bacterium transformed ferulate under strictly anaerobic conditions (N2-CO2 gas phase). Ferulate (1.55 mM) was demethoxylated and dehydroxylated with subsequent reduction of the side chain, resulting in production of phenylpropinate and phenylacetate. Under aerobic conditions, the substrate was completely degraded, with transient appearance of caffeate as the first aromatic intermediate and beta-ketoadipate as an aliphatic intermediate. The pure culture has been tentatively assigned to the genus Enterobacter with the type strain DG-6 (ATCC 35929). Tentative pathways for both fermentative and oxidative degradation of ferulate are now proposed. Images PMID:4083873

Grbi?-Gali?, D

1985-01-01

37

Dispersal of non-sporeforming anaerobic bacteria from the skin.  

PubMed

Dispersal of non-sporeforming anaerobic bacteria was studied. Skin samples were taken from the subjects, and dispersed from different parts of the body was examined. The number of anaerobic bacteria dispersed was not correlated to their density on the surface of skin area exposed. The highest density of anaerobic bacteria on the skin was found in the face and upper trunk, but the highest yield of anaerobic bacteria dispersed came from the lower trunk. The dominant anaerobic bacteria dispersed were Propionibacterium acnes, but Propionibacterium avidum, Propionibacterium granulosum and Gram-positive cocci were also isolated from the dispersal samples. Peptococcus magnus was the most common coccus isolated. For the less frequently isolated bacteria, the best correlation was found between the perineal flora and airborne bacteria. A comparison was also made of bacterial dispersal by naked and dressed subjects. The dispersal of both aerobic and anaerobic bacteria was higher when the subjects were dressed in conventional operating theatre cotton clothing than when they were naked. The increased dispersal of anaerobic bacteria when the subjects were dressed was mainly due to increased dispersal of Propionibacterium sp. PMID:6806353

Benediktsdóttir, E; Hambraeus, A

1982-06-01

38

[Identification of anaerobic bacteria isolated from various clinical specimens and determination of antibiotic susceptibilities].  

PubMed

Routine isolation, identification and susceptibility testing of anaerobic bacteria present several difficulties leading to defects in the determination of local susceptibility patterns which will guide empirical treatment protocols. This study was carried out to identify the anaerobic bacteria isolated from various clinical materials obtained from the suspected patients with anaerobic infection and to determine the antibiotic susceptibilities against several antibiotics. One hundred clinical specimens (36 blood, 31 abscess, 12 peritoneal fluid, 7 joint fluid, 7 pleural fluid, 3 biopsies, 3 cerebrospinal fluids and 1 surgical wound) that were examined in our laboratory during March 20-October 30 2007, were included in the study. The specimens were collected and transported under anaerobic conditions and inoculated to conventional aerobic media and to Wilkins Chalgren agar, Schaedler agar and chopped-meat broth for anaerobic isolation. Isolated anaerobic bacteria were identified with API 20A panels (Bio-Merieux, France) via conventional methods and by the help of AN-IDENT Discs (Oxoid, England). Penicillin G, clindamycin, cefoxitin, metronidazole, piperacillin/tazobactam and imipenem susceptibility tests were performed with E- test method. Twenty two anaerobic bacteria were isolated from 14 clinical specimens; 7 of the specimens yielding the growth of more than one type of anaerobic bacteria and 8 specimens yielding both anaerobic and facultative anaerobic bacterial (4 Escherichia coli and 4 Enterococcus spp.) growth. Anaerobic bacteria were isolated in 89 abscess and in 6 peritoneal fluid specimens. The distribution of the anaerobic bacteria identified among these specimens were as follows: Bacteroides fragilis (n = 6), Bacteroides spp. other than B.fragilis (n = 4), Clostridium spp. (n = 2), Fusobacterium necrophorum/nucleatum (n = 1), Prevotella intermedia/disiens (n = 1), Peptococcus niger (n = 2), Peptostreptococcus spp. (n = 5), and Lactobacillus acidophilus/lenseii (n = 1). Beta-lactamase activity was detected only in 2 of the 6 B. fragilis isolates. All of the isolates were susceptible to imipenem and piperacillin/tazobactam. The highest rate of resistance was detected against penicillin G (9/22; 41%). While anaerobic gram-positive cocci (n = 7) were found to be sensitive to all antibiotics, the rate of resistance among anaerobic gram-negative bacilli were 75% (9/12) to penicillin, 33.3% (4/12) to clindamycin, 8.3% (1/12) to metronidazole. Among anaerobic gram-positive bacilli (n = 3), 2 were resistant to metronidazole, one to clindamycin and one to cefoxitin. The results of this first anaerobic antimicrobial susceptibility testing study performed at Konya area in Turkey revealed that penicillin was not appropriate in empirical treatment of anaerobic infections, clindamycin susceptibility should be tested before use, metronidazole and cefoxitin could be used in empirical treatment and imipenem and piperacillin/tazobactam should be saved for the treatment of complicated infections and infections caused by resistant bacteria. PMID:20549955

Do?an, Metin; Baysal, Bülent

2010-04-01

39

Oxygen Effect on the Low Temperature Tolerance of Facultative Anaerobes from Antarctica, Alaska, and Patagonia  

NASA Technical Reports Server (NTRS)

Psychrotolerance as an adaptation to survival in extreme environments is widespread among many of the mesophilic microorganisms. Red-ox potential, pH and salinity could significantly alter the features of ecosystems by providing liquid water at subzero temperatures. Furthermore, organisms can respond to temperature changes by several known mechanisms, including changing the conformation capacities of constitutional proteins or by the synthesis of mucopolysaccharides around the cell wall and membrane. Such protective mechanisms make it possible for cells to not only passively survive low-temperature in a state of anabiosis, but also to be capable of actively metabolizing substrates and reproducing normally. The physiological and biochemical characteristics of species as well as genetics could be remarkably changed due to -on and surviving m extreme environments. The cold shock genes for some of the studied strains of psychrotolerant facultative anaerobes already were published In this paper we present experimental data for psychrotolerant facultative anaerobes isolated from geographically different cold regions of our planet. We show the growth response on the changing of anaerobic conditions to aerobic with cultivation at subzero temperatures.

Pikuta, Elena V.; Hoover, Richard B.

2004-01-01

40

Growth of the Facultative Anaerobes from Antarctica, Alaska, and Patagonia at Low Temperatures  

NASA Technical Reports Server (NTRS)

Psychotolerance, as an adaptation for surviving in extreme environments, is widespread among mesophilic microorganisms. Physico-chemical factors such as pressure, red-ox potential, pH and salinity could significantly alter the features of ecosystems by providing liquid water at subzero temperatures. Furthermore, organisms can respond to temperature changes by several known mechanisms, including changing the conformation capacities of constitutional proteins or by the synthesis of mucopolysaccharides around the cell wall and membrane. Such protective mechanisms make it possible for cells to not only passively survive low temperatures in a state of anabiosis, but also to be capable of actively metabolizing substrates and reproducing normally. The physiological and biochemical characteristics of the species, as well as genetics, could be remarkably changed due to adaptation and surviving in extreme environments. The cold shock genes of some of the studied strains of psychotolerant facultative anaerobes were reported previously. In this paper we present experimental data for psychotolerant, non spore-forming, facultative anaerobes isolated from geographically different cold regions of our planet. We show the growth response on changing from anaerobic conditions to aerobic with cultivation at low temperatures.

Pikuta, Elena V.; Hoover, Richard B.

2004-01-01

41

Clostridium thermoalcaliphilum sp. nov., an anaerobic and thermotolerant facultative alkaliphile  

SciTech Connect

An anaerobic and thermophilic alkaliphile, strain JW/YL23-2{sub T} (T = type strain), was isolated from sewage sludge obtained from a sewage plant in Atlanta, Ga. at pH 10.1 and 50{degrees}C, the doubling time of this strain was 19 min. Strain JW/YL23-2{sub T}, a motile rod-shaped bacterium with 2 to 12 peritrichous flagella, exhibited a negative Gram stain reaction but was gram-type positive as judged by the polymyxin B test. No heat-stable (85{degrees}C, 15 min) endospores were detected. At 50{degrees}C, growth occurred at pH values ranging from 7.0 to 11.0; the optimum pH was 9.6 to 10.1. The temperature range for growth ranged from 27 to 57.5{degrees}C; the optimum temperature was 48 to 51{degrees}C (pH 10.1). Dissimilatory sulfate reduction was not detected. The organism utilized glucose, fructose, sucrose, maltose, cellobiose, and Casamino Acids. The DNA G+C content was 32 mol% (as determined by chemical analysis). A 16S rRNA sequence analysis revealed a 2% inferred evolutionary distance to Clostridium paradoxum. However, the cell wall type of strain JW/YL23-2{sup T} was A4{beta} (L-Orn-D-Asp), while that of C. paradoxum was Al{sub {tau}} (m-diaminopimelic acid direct). On the basis of the alkaline pH values and high temperatures for optimal growth, the inability to form spores, and other characteristics different from C. paradoxum characteristics, strain JW/YL-23-2 was placed in a new species, Clostridium thermoalcaliphilum; JW/YL23-2 (= DSM 7309) is the type strain of this new species.

Youhong Li; Engle, M.; Wiegel, J. [Univ. of Georgia, Athens, GA (United States)] [and others

1994-01-01

42

Two Cases of Diskitis Attributable to Anaerobic Bacteria in Children  

Microsoft Academic Search

Diskitis, an inflammation of the interver- tebral disk, is generally attributable to Staphylococcus aureus and rarely Staphylococcus epidermidis, Kingella kingae, Enterobacteriaciae, and Streptococcus pneu- moniae. In many cases, no bacterial growth is obtained from infected intervertebral discs. Although anaerobic bacteria were recovered from adults with spondylodisci- tis, these organisms were not reported before from chil- dren. The recovery of anaerobic

Itzhak Brook

43

Isolation of halotolerant, thermotolerant, facultative polymer-producing bacteria and characterization of the exopolymer  

Microsoft Academic Search

Over 200 bacterial strains were selected for anaerobic growth at 50°C and extracellular polysaccharide production in a sucrose-mineral salts medium with NaNOâ and up to 10% NaCl. The predominant cell type was an encapsulated gram-positive, motile, facultative spore-forming rod similar to Bacillus species. Strain SP018 grew and produced the polysaccharide on a variety of substrates at salinities up to 12%

S. M. Pfiffner; M. J. McInerney; G. E. Jenneman; R. M. Knapp

1986-01-01

44

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. PMID:16535004

Roslev, P.; King, G. M.

1995-01-01

45

Effects of substrate concentrations on the growth of heterotrophic bacteria and algae in secondary facultative ponds  

Microsoft Academic Search

This paper presents the effect of substrate concentration on the growth of a mixed culture of algae and heterotrophic bacteria in secondary facultative ponds (SFPs) utilizing settled domestic sewage as a sole source of organic carbon. The growth of the mixed culture was studied at the concentrations ranging between 200 and 800mg COD\\/l in a series of batch chemostat reactors.

S. Kayombo; T. S. A. Mbwette; J. H. Y. Katima; S. E Jorgensen

2003-01-01

46

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

47

Isolation of thermotolerant, halotolerant, facultative biosurfactant-producing bacteria  

Microsoft Academic Search

Several facultative bacterial strains tolerant to high temperature and salinity were isolated from the oil reservoir brines\\u000a of an Iranian oil field (Masjed-I Soleyman). Some of these isolates were able to grow up to 60°C and at high concentration\\u000a of NaCl (15% w\\/v). One of the isolates grew at 40°C, while it was able to grow at 15% w\\/v NaCl.

H. Ghojavand; F. Vahabzadeh; M. Mehranian; M. Radmehr; Kh. A. Shahraki; F. Zolfagharian; M. A. Emadi; E. Roayaei

2008-01-01

48

Serum Antibodies to Oral Anaerobic Bacteria in Patients With Rheumatoid Arthritis  

PubMed Central

Abstract and Introduction Abstract Background This study was conducted to determine the component that causes the disease in rheumatoid arthritis (RA), which shows great resemblance to periodontitis in a pathologic context. Materials and Methods Within this study, the pathogen-specific IgG levels formed against Porphyromonas gingivalis FDC 381, Prevotella melaninogenica ATCC 25845, Actinobacillus actinomycetemcomitans Y4, Bacteroides forsythus ATCC 43047, and Prevotella intermedia 25611 oral bacteria were researched from the blood serum samples of 30 RA patients and 20 healthy controls with the enzyme-linked immunosorbent assay (ELISA) method. Results The IgG levels of P gingivalis, P intermedia, P melaninogenica, and B forsythus were found to be significantly higher in RA patients when compared with those of the controls. Of the other bacteria antibodies, A actinomycetemcomitans was not found at greater levels in RA serum samples in comparison with the healthy samples. Conclusion The antibodies formed against P gingivalis, P intermedia, P melaninogenica, and B forsythus could be important to the etiopathogenesis of RA. Introduction Rheumatoid arthritis (RA) is a polyarticular, chronic, inflammatory, and systemic disease.[1] In many previous studies, this rheumatic disease was found at high ratios for individuals with periodontitis and RA shows resemblance to periodontitis in many aspects pathologically.[2,3] HLA-DR4 tissue antigens are found at high frequencies in both patients with periodontitis and with RA. HLA-DR4 tissue antigens and their subtypes are directly associated with each disease.[4,5] Porphyromonas gingivalis, Prevotella intermedia, Prevotella melaninogenica, and Bacteroides forsythus are gram-negative small basil quality obligate anaerobic bacteria and are held directly responsible for the formation of periodontitis (Periodontopathic bacteria). These bacteria usually secrete brown-black pigments and form colonies when they reproduce in blood agar plates used for their cultivation.[6] These bacteria were classified in the Bacteroides genus until 1988 and 1990, when they were reclassified to the Porphyromonas and Prevotella genera, respectively, in accordance with new classification strategies made by Shah and Collins.[7,8] These bacteria are members of the normal human mouth flora, where they cause endodontitis, odontogenic inflammation, gingivitis, and mainly periodontitis. They are also found commensally in the body flora, where they cause chronic sinusitis, chronic recurrent tonsillitis, bronchitis, pneumonia, chronic otitis media, parotitis, intra-abdominal infection, genitourinary infection, and wound infections in immune-suppressed individuals as well as when in conjunction with facultative anaerobic bacteria (ie, Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, Klebsiella pneumonia, Proteus mirabilis, and Escherichia coli).[9] A significant point here is that, although these bacteria are obligate anaerobic bacteria, when in conjunction with the facultative anaerobic bacteria mentioned above, they lead to mixed types of infections. In this study, we investigated the oral Bacteroides, Porphyromonas, and Prevotella bacteria antibodies usually found in periodontitis etiopathogenesis but from serum samples of RA patients. PMID:16369381

Ogrendik, Mesut; Kokino, Siranus; Ozdemir, Ferda; Bird, Philip S.; Hamlet, Stephen

2005-01-01

49

Biochemistry and physiology of anaerobic bacteria  

SciTech Connect

We welcome you to The Power of Anaerobes. This conference serves two purposes. One is to celebrate the life of Harry D. Peck, Jr.,who was born May 18, 1927 and would have celebrated his 73rd birthday at this conference. He died November 20, 1998. The second is to gather investigators to exchange views within the realm of anaerobic microbiology, an area in which tremendous progress has been seen during recent years. It is sufficient to mention discoveries of a new form of life (the archaea), hyper or extreme thermophiles, thermophilic alkaliphiles and anaerobic fungi. With these discoveries has come a new realization about physiological and metabolic properties of microorganisms, and this in turn has demonstrated their importance for the development, maintenance and sustenance of life on Earth.

NONE

2000-05-18

50

Recovery of anaerobic bacteria from small inocula: a model for blood culture studies  

Microsoft Academic Search

The recovery of anaerobic, facultative anaerobic, and aerobic pathogens from very small inocula was studied under conditions that could be related to routine blood culture procedures. Results with Brain Heart Infusion broth were unsatisfactory. Freshly prepared Brewer thioglycollate medium gave apparently good results, but there are disadvantages when this medium is used for blood culture. Results with Difco Thiol broth

J G Collee; B I Duerden; R Brown

1977-01-01

51

In vitro sensitivity of oral, gram-negative, facultative bacteria to the bactericidal activity of human neutrophil defensins.  

PubMed Central

Neutrophils play a major role in defending the periodontium against infection by oral, gram-negative, facultative bacteria, such as Actinobacillus actinomycetemcomitans, Eikenella corrodens, and Capnocytophaga spp. We examined the sensitivity of these bacteria to a mixture of low-molecular-weight peptides and highly purified individual defensin peptides (HNP-1, HNP-2, and HNP-3) isolated from human neutrophils. Whereas the Capnocytophaga spp. strains were killed significantly by the mixed human neutrophil peptides, the A. actinomycetemcomitans and E. corrodens strains were resistant. Killing was attributable to the defensins. The bactericidal activities of purified defensins HNP-1 and HNP-2 were equal, and both of these activities were greater than HNP-3 activity against strains of Capnocytophaga sputigena and Capnocytophaga gingivalis. The strain of Capnocytophaga ochracea was more sensitive to defensin-mediated bactericidal activity than either C. sputigena or C. gingivalis was. The three human defensins were equipotent in killing C. ochracea. C. ochracea was killed under aerobic and anaerobic conditions and over a broad pH range. Killing was most effective under hypotonic conditions but also occurred at physiologic salt concentrations. We concluded that Capnocytophaga spp. are sensitive to oxygen-independent killing by human defensins. Additional studies will be required to identify other components that may equip human neutrophils to kill A. actinomycetemcomitans, E. corrodens, and other oral gram-negative bacteria. Images PMID:2254020

Miyasaki, K T; Bodeau, A L; Ganz, T; Selsted, M E; Lehrer, R I

1990-01-01

52

Material and method for promoting the growth of anaerobic bacteria  

DOEpatents

A material and method is disclosed for promoting the growth of anaerobic bacteria which includes a nutrient media containing a hydrogen donor and sterile membrane fragments of bacteria having an electron transfer system which reduces oxygen to water. Dissolved oxygen in the medium is removed by adding the sterile membrane fragments to the nutrient medium and holding the medium at a temperature of about 10 to about 60 C until the dissolved oxygen is removed. No Drawings

Adler, H.I.

1984-10-09

53

Material and method for promoting the growth of anaerobic bacteria  

DOEpatents

A material and method for promoting the growth of anaerobic bacteria which includes a nutrient media containing a hydrogen donor and sterile membrane fragments of bacteria having an electron transfer system which reduces oxygen to water. Dissolved oxygen in the medium is removed by adding the sterile membrane fragments to the nutrient medium and holding the medium at a temperature of about 10.degree. to about 60.degree. C. until the dissolved oxygen is removed.

Adler, Howard I. (128 Indian La., Oak Ridge, TN 37830)

1984-01-01

54

[Amphibacillus fermentum sp. nov., Amphibacillus tropicus sp. nov.--new alkaliphilic, facultatively anaerobic, saccharolytic Bacilli from Lake Magadi].  

PubMed

New alkaliphilic, saccharolytic, rod-shaped, gram-positive bacteria resistant to heating and drying and phylogenetically affiliated to the Bacillus lineage were isolated under strictly anaerobic conditions from sediments of the alkaline and highly mineralized Lake Magadi. Strain Z-7792 forms endospores; in strain Z-7984, endospore formation was not revealed. The strains are capable of both anaerobic growth (at the expense of fermentation of glucose and certain mono- and disaccharides with the formation of formate, ethanol, and acetate) and aerobic growth. Among polysaccharides, the strains hydrolyze starch, glycogen, and xylan. Yeast extract or methionine are required for growth. The strains are strict alkaliphiles exhibiting obligate requirement for Na+ and carbonate ions but not for Cl- ion. Growth occurs at a total mineralization as high as 3.3-3.6 M Na+, with an optimum at 1-1.7 M Na+. Strain Z-7792 is an obligate alkaliphile with a pH growth range of 8.5-11.5 and an optimum of 9.5-9.7. Strain Z-7984 grows in a pH range of 7.0-10.5 with an optimum at 8.0-9.5. Both strains are mesophiles having a growth optimum at 37-38 degrees C. They belong to bacilli with a low G + C content. The G + C contents of the DNA of strains Z-7792 and Z-7984 are 39.2 and 41.5 mol%, respectively. These isolates of facultatively anaerobic, strictly alkaliphilic, Na(+)-dependent bacilli can be considered representatives of the ecological group adapted to the life at drying-up shoars of soda lakes. Because of their independence of NaCl and lack of obligate dependence on sodium carbonates, the isolates are to be assigned to athalassophilic organisms. According to their physiological and phylogenetic characteristics, they taxonomically belong to group 1 of the species of bacilli, occupying a position intermediate between the genera Amphibacillus and Gracilibacillus. The isolates are described as new species of Amphibacillus: A. fermentum (type strain, Z-7984T) and A. tropicus (type strain, Z-7792T). PMID:11785140

Zhilina, T N; Garnova, E S; Turova, T P; Kostrikina, N A; Zavarzin, G A

2001-01-01

55

Anaerobic degradation of pimelate by newly isolated denitrifying bacteria  

Microsoft Academic Search

A C, dicarboxylic (pimelic) acid derivative is postulated as an intermediate in anaerobic degradation of benzoate. Four strains of Gram-negative, nitrate- reducing bacteria capable of growth with both pimelate and benzoate as sole carbon and energy source were isolated. The metabolism of strain LP-1, which was enriched from activated sludge with pimelate as substrate, was studied in detail. This strain

Corinna Gallus; Bernhard Schink

1994-01-01

56

Killing of anaerobic pathogens by predatory bacteria.  

PubMed

Recently, the predation of Bdellovibrio bacteriovorus on a periodontal pathogen has been described. The current study explores the potential antimicrobial activity of a range of predatory bacteria against key periodontal pathogens. A number of representatives from the Bdellovibrio, Bacteriovorax and Peredibacter lineages (called 'BALOs') were tested for their activity towards a group of key periodontal pathogens and an optimal multiplicity of infection was established. As the oral cavity contains a wide variety of bacteria that are not preyed upon, it was investigated if they can have an effect on the predation efficiency of BALOs. It was concluded that a number of important variables involved in bacterial predation are found to be compatible with the composition of the oral microbiota. This finding makes the case for continued study of the potential for BALOs to combat periodontal pathogens. PMID:21214872

Van Essche, M; Quirynen, M; Sliepen, I; Loozen, G; Boon, N; Van Eldere, J; Teughels, W

2011-02-01

57

[Anaerobic bacteria 150 years after their discovery by Pasteur].  

PubMed

In 2011 we celebrated the 150th anniversary of the discovery of anaerobic bacteria by Louis Pasteur. The interest of the biomedical community on such bacteria is still maintained, and is particularly focused on Clostridium difficile. In the past few years important advances in taxonomy have been made due to the genetic, technological and computing developments. Thus, a significant number of new species related to human infections have been characterised, and some already known have been reclassified. At pathogenic level some specimens of anaerobic microflora, that had not been isolated from human infections, have been now isolated in some clinical conditions. There was emergence (or re-emergence) of some species and clinical conditions. Certain anaerobic bacteria have been associated with established infectious syndromes. The virulence of certain strains has increased, and some hypotheses on their participation in certain diseases have been given. In terms of diagnosis, the routine use of MALDI-TOF has led to a shortening of time and a cost reduction in the identification, with an improvement directly related to the improvement of data bases. The application of real-time PCR has been another major progress, and the sequencing of 16srRNA gene and others is currently a reality for several laboratories. Anaerobes have increased their resistance to antimicrobial agents, and the emergence of resistance to carbapenems and metronidazole, and multi-resistance is a current reality. In this situation, linezolid could be an effective alternative for Bacteroides. Fidaxomicin is the only anti-anaerobic agent introduced in the recent years, specifically for the diarrhoea caused by C.difficile. Moreover, some mathematical models have also been proposed in relation with this species. PMID:23648369

García-Sánchez, José Elías; García-Sánchez, Enrique; Martín-Del-Rey, Ángel; García-Merino, Enrique

2015-02-01

58

Anaerobic degradation of hydroaromatic compounds by newly isolated fermenting bacteria  

Microsoft Academic Search

Aerobic organisms degrade hydroaromatic compounds via the hydroaromatic pathway yielding protocatechuic acid which is further metabolized by oxygenase-mediated ring fission in the 3-oxoadipate pathway. No information exists on anaerobic degradation of hydroaromatics so far. We enriched and isolated from various sources of anoxic sediments several strains of rapidly growing gram-negative bacteria fermenting quinic (1,3,4,5-tetrahydroxy-cyclohexane-1-carboxylic acid) and shikimic acid (3,4,5-trihydroxy-1-cyclohexene-1-carboxylic acid)

Andreas Brune; Berhard Schink

1992-01-01

59

Iron biomineralization by anaerobic neutrophilic iron-oxidizing bacteria  

Microsoft Academic Search

Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate-dependent iron-oxidizing bacterium Acidovorax sp. strain BoFeN1 in the presence of dissolved Fe(II) using electron microscopy and Scanning Transmission X-ray Microscopy (STXM).

Jennyfer Miot; Karim Benzerara; Guillaume Morin; Andreas Kappler; Sylvain Bernard; Martin Obst; Céline Férard; Fériel Skouri-Panet; Jean-Michel Guigner; Nicole Posth; Matthieu Galvez; Gordon E. Brown; François Guyot

2009-01-01

60

Use of Presumpto Plates to identify anaerobic bacteria.  

PubMed Central

Identification of anaerobic bacteria requires special media and growth conditions that contribute to a higher cost per identification than that for aerobic isolates. Newer rapid methods streamline the identification process, but confirmation to the species level is often difficult. The Presumpto Plate method for the identification of commonly encountered anaerobes consists of three quadrant plates, each containing four conventional media, that result in the generation of 21 test parameters: growth on Lombard-Dowell medium; production of indole, indole derivative, catalase, lecithinase, and lipase; proteolysis of milk, H2S, and esculin; growth on 20% bile; precipitate on bile; DNase, glucose, casein, starch, and gelatin hydrolysis; and fermentation of lactose, mannitol, and rhamnose. Identification charts were developed by using the results from 2,300 anaerobic isolates. Because conventional media were used, there was a high degree of agreement between the Presumpto Plate method and the reference method when testing commonly encountered anaerobes. The Presumpto Plate method is as accurate as commercially available enzyme systems for the identification of many anaerobic species but is less expensive to perform. PMID:7615728

Whaley, D N; Wiggs, L S; Miller, P H; Srivastava, P U; Miller, J M

1995-01-01

61

Oxidation and methylation of dissolved elemental mercury by anaerobic bacteria  

NASA Astrophysics Data System (ADS)

Methylmercury is a neurotoxin that poses significant health risks to humans. Some anaerobic sulphate- and iron-reducing bacteria can methylate oxidized forms of mercury, generating methylmercury. One strain of sulphate-reducing bacteria (Desulfovibrio desulphuricans ND132) can also methylate elemental mercury. The prevalence of this trait among different bacterial strains and species remains unclear, however. Here, we compare the ability of two strains of the sulphate-reducing bacterium Desulfovibrio and one strain of the iron-reducing bacterium Geobacter to oxidize and methylate elemental mercury in a series of laboratory incubations. Experiments were carried out under dark, anaerobic conditions, in the presence of environmentally relevant concentrations of elemental mercury. We report differences in the ability of these organisms to oxidize and methylate elemental mercury. In line with recent findings, we show that D.desulphuricans ND132 can both oxidize and methylate elemental mercury. We find that the rate of methylation of elemental mercury is about one-third the rate of methylation of oxidized mercury. We also show that Desulfovibrio alaskensis G20 can oxidize, but not methylate, elemental mercury. Geobacter sulphurreducens PCA is able to oxidize and methylate elemental mercury in the presence of cysteine. We suggest that the activity of methylating and non-methylating bacteria may together enhance the formation of methylmercury in anaerobic environments.

Hu, Haiyan; Lin, Hui; Zheng, Wang; Tomanicek, Stephen J.; Johs, Alexander; Feng, Xinbin; Elias, Dwayne A.; Liang, Liyuan; Gu, Baohua

2013-09-01

62

Oxidation and methylation of dissolved elemental mercury by anaerobic bacteria  

SciTech Connect

Methylmercury is a neurotoxin that poses significant health risks to humans. Some anaerobic sulphate- and iron-reducing bacteria can methylate oxidized forms of mercury, generating methylmercury1-4. One strain of sulphate-reducing bacteria (Desulfovibrio desulfuricans ND132) can also methylate elemental mercury5. The prevalence of this trait among different bacterial strains and species remains unclear, however. Here, we compare the ability of two strains of the sulphate-reducing bacterium Desulfovibrio and one strain of the iron-reducing bacterium Geobacter to oxidise and methylate elemental mercury in a series of laboratory incubations. Experiments were carried out under dark, anaerobic conditions, in the presence of environmentally-relevant concentrations of elemental mercury. We report differences in the ability of these organisms to oxidise and methylate elemental mercury. In line with recent findings5, we show that Desulfovibrio desulfuricans ND132 can both oxidise and methylate elemental mercury. However, the rate of methylation of elemental mercury is only about one third the rate of methylation of oxidized mercury. We also show that Desulfovibrio alaskensis G20 can oxidise, but not methylate, elemental mercury. Geobacter sulfurreducens PCA is able to oxidise and methylate elemental mercury in the presence of cysteine. We suggest that the activity of methylating and non-methylating bacteria may together enhance the formation of methylmercury in anaerobic environments.

Hu, Haiyan [ORNL] [ORNL; Lin, Hui [ORNL] [ORNL; Zheng, Wang [ORNL] [ORNL; Tomanicek, Stephen J [ORNL] [ORNL; Johs, Alexander [ORNL] [ORNL; Feng, Xinbin [ORNL] [ORNL; Elias, Dwayne A [ORNL] [ORNL; Liang, Liyuan [ORNL] [ORNL; Liang, Liyuan [ORNL] [ORNL; Gu, Baohua [ORNL] [ORNL

2013-01-01

63

Biogeography of anaerobic ammonia-oxidizing (anammox) bacteria.  

PubMed

Anaerobic ammonia-oxidizing (anammox) bacteria are able to oxidize ammonia and reduce nitrite to produce N2 gas. After being discovered in a wastewater treatment plant (WWTP), anammox bacteria were subsequently characterized in natural environments, including marine, estuary, freshwater, and terrestrial habitats. Although anammox bacteria play an important role in removing fixed N from both engineered and natural ecosystems, broad scale anammox bacterial distributions have not yet been summarized. The objectives of this study were to explore global distributions and diversity of anammox bacteria and to identify factors that influence their biogeography. Over 6000 anammox 16S rRNA gene sequences from the public database were analyzed in this current study. Data ordinations indicated that salinity was an important factor governing anammox bacterial distributions, with distinct populations inhabiting natural and engineered ecosystems. Gene phylogenies and rarefaction analysis demonstrated that freshwater environments and the marine water column harbored the highest and the lowest diversity of anammox bacteria, respectively. Co-occurrence network analysis indicated that Ca. Scalindua strongly connected with other Ca. Scalindua taxa, whereas Ca. Brocadia co-occurred with taxa from both known and unknown anammox genera. Our survey provides a better understanding of ecological factors affecting anammox bacterial distributions and provides a comprehensive baseline for understanding the relationships among anammox communities in global environments. PMID:25147546

Sonthiphand, Puntipar; Hall, Michael W; Neufeld, Josh D

2014-01-01

64

Biogeography of anaerobic ammonia-oxidizing (anammox) bacteria  

PubMed Central

Anaerobic ammonia-oxidizing (anammox) bacteria are able to oxidize ammonia and reduce nitrite to produce N2 gas. After being discovered in a wastewater treatment plant (WWTP), anammox bacteria were subsequently characterized in natural environments, including marine, estuary, freshwater, and terrestrial habitats. Although anammox bacteria play an important role in removing fixed N from both engineered and natural ecosystems, broad scale anammox bacterial distributions have not yet been summarized. The objectives of this study were to explore global distributions and diversity of anammox bacteria and to identify factors that influence their biogeography. Over 6000 anammox 16S rRNA gene sequences from the public database were analyzed in this current study. Data ordinations indicated that salinity was an important factor governing anammox bacterial distributions, with distinct populations inhabiting natural and engineered ecosystems. Gene phylogenies and rarefaction analysis demonstrated that freshwater environments and the marine water column harbored the highest and the lowest diversity of anammox bacteria, respectively. Co-occurrence network analysis indicated that Ca. Scalindua strongly connected with other Ca. Scalindua taxa, whereas Ca. Brocadia co-occurred with taxa from both known and unknown anammox genera. Our survey provides a better understanding of ecological factors affecting anammox bacterial distributions and provides a comprehensive baseline for understanding the relationships among anammox communities in global environments. PMID:25147546

Sonthiphand, Puntipar; Hall, Michael W.; Neufeld, Josh D.

2014-01-01

65

Anaerobic Ammonium-Oxidizing Bacteria: Unique Microorganisms with Exceptional Properties  

PubMed Central

Summary: Anaerobic ammonium-oxidizing (anammox) bacteria defy many microbiological concepts and share numerous properties with both eukaryotes and archaea. Among their most intriguing characteristics are their compartmentalized cell plan and archaeon-like cell wall. Here we review our current knowledge about anammox cell biology. The anammox cell is divided into three separate compartments by bilayer membranes. The anammox cell consists of (from outside to inside) the cell wall, paryphoplasm, riboplasm, and anammoxosome. Not much is known about the composition or function of both the anammox cell wall and the paryphoplasm compartment. The cell wall is proposed to be proteinaceous and to lack both peptidoglycan and an outer membrane typical of Gram-negative bacteria. The function of the paryphoplasm is unknown, but it contains the cell division ring. The riboplasm resembles the standard cytoplasmic compartment of other bacteria; it contains ribosomes and the nucleoid. The anammoxosome occupies most of the cell volume and is a so-called “prokaryotic organelle” analogous to the eukaryotic mitochondrion. This is the site where the anammox reaction takes place, coupled over the curved anammoxosome membrane, possibly giving rise to a proton motive force and subsequent ATP synthesis. With these unique properties, anammox bacteria are food for thought concerning the early evolution of the domains Bacteria, Archaea, and Eukarya. PMID:22933561

Jetten, Mike S. M.

2012-01-01

66

Draft Genome Sequence of Paenibacillus Strain P1XP2, a Polysaccharide-Degrading, Thermophilic, Facultative Anaerobic Bacterium Isolated from a Commercial Bioreactor Degrading Food Waste  

PubMed Central

The analysis of the ~5.8-Mb draft genome sequence of a moderately thermophilic, heterotrophic, facultative anaerobic bacterium, Paenibacillus strain P1XP2, identified genes for enzymes with the potential for degrading complex food wastes, a property consistent with the ecological habitat of the isolate. PMID:25635015

Adelskov, Joseph

2015-01-01

67

Overcoming the hypoxic barrier to radiation therapy with anaerobic bacteria.  

PubMed

The low level of oxygenation within tumors is a major cause of radiation treatment failures. We theorized that anaerobic bacteria that can selectively destroy the hypoxic regions of tumors would enhance the effects of radiation. To test this hypothesis, we used spores of Clostridium novyi-NT to treat transplanted tumors in mice. The bacteria were found to markedly improve the efficacy of radiotherapy in several of the mouse models tested. Enhancement was noted with external beam radiation derived from a Cs-137 source, systemic radioimmunotherapy with an I-131-conjugated monoclonal antibody, and a previously undescribed form of experimental brachytherapy using plaques loaded with I-125 seeds. C. novyi-NT spores added little toxicity to the radiotherapeutic regimens, and the combination resulted in long-term remissions in a significant fraction of animals. PMID:14657371

Bettegowda, Chetan; Dang, Long H; Abrams, Ross; Huso, David L; Dillehay, Larry; Cheong, Ian; Agrawal, Nishant; Borzillary, Scott; McCaffery, J Michael; Watson, E Latice; Lin, Kuo-Shyan; Bunz, Fred; Baidoo, Kwamena; Pomper, Martin G; Kinzler, Kenneth W; Vogelstein, Bert; Zhou, Shibin

2003-12-01

68

Fourth Belgian multicentre survey of antibiotic susceptibility of anaerobic bacteria  

PubMed Central

Objectives To collect recent data on the susceptibility of anaerobes to antimicrobial agents with known activity against anaerobes, and to compare them with results from previous Belgian multicentre studies. Methods Four hundred and three strict anaerobic clinical isolates were prospectively collected from February 2011 to April 2012 in eight Belgian university hospitals. MICs were determined by one central laboratory for 11 antimicrobial agents using Etest methodology. Results According to EUCAST breakpoints, >90% of isolates were susceptible to amoxicillin/clavulanate (94%), piperacillin/tazobactam (91%), meropenem (96%), metronidazole (92%) and chloramphenicol (98%), but only 70% and 40% to clindamycin and penicillin, respectively. At CLSI recommended breakpoints, only 71% were susceptible to moxifloxacin and 79% to cefoxitin. MIC50/MIC90 values for linezolid and for tigecycline were 1/4 and 0.5/4 mg/L, respectively. When compared with survey data from 2004, no major differences in susceptibility profiles were noticed. However, the susceptibility of Prevotella spp. and other Gram-negative bacilli to clindamycin decreased from 91% in 1993–94 and 82% in 2004 to 69% in this survey. Furthermore, the susceptibility of clostridia to moxifloxacin decreased from 88% in 2004 to 66% in 2011–12 and that of fusobacteria from 90% to 71%. Conclusions Compared with previous surveys, little evolution was seen in susceptibility, except a decline in activity of clindamycin against Prevotella spp. and other Gram-negative bacteria, and of moxifloxacin against clostridia. Since resistance was detected to all antibiotics, susceptibility testing of anaerobic isolates is indicated in severe infections to confirm appropriateness of antimicrobial therapy. PMID:24008826

Wybo, Ingrid; Van den Bossche, Dorien; Soetens, Oriane; Vekens, Evilien; Vandoorslaer, Kristof; Claeys, Geert; Glupczynski, Youri; Ieven, Margareta; Melin, Pierrette; Nonhoff, Claire; Rodriguez-Villalobos, Hector; Verhaegen, Jan; Piérard, Denis

2014-01-01

69

Complete Genome of Ignavibacterium album, a Metabolically Versatile, Flagellated, Facultative Anaerobe from the Phylum Chlorobi  

PubMed Central

Prior to the recent discovery of Ignavibacterium album (I. album), anaerobic photoautotrophic green sulfur bacteria (GSB) were the only members of the bacterial phylum Chlorobi that had been grown axenically. In contrast to GSB, sequence analysis of the 3.7-Mbp genome of I. album shows that this recently described member of the phylum Chlorobi is a chemoheterotroph with a versatile metabolism. I. album lacks genes for photosynthesis and sulfur oxidation but has a full set of genes for flagella and chemotaxis. The occurrence of genes for multiple electron transfer complexes suggests that I. album is capable of organoheterotrophy under both oxic and anoxic conditions. The occurrence of genes encoding enzymes for CO2 fixation as well as other enzymes of the reductive TCA cycle suggests that mixotrophy may be possible under certain growth conditions. However, known biosynthetic pathways for several amino acids are incomplete; this suggests that I. album is dependent upon on exogenous sources of these metabolites or employs novel biosynthetic pathways. Comparisons of I. album and other members of the phylum Chlorobi suggest that the physiology of the ancestors of this phylum might have been quite different from that of modern GSB. PMID:22661972

Liu, Zhenfeng; Frigaard, Niels-Ulrik; Vogl, Kajetan; Iino, Takao; Ohkuma, Moriya; Overmann, Jörg; Bryant, Donald A.

2012-01-01

70

Fuel from Bacteria: Bioconversion of Carbon Dioxide to Biofuels by Facultatively Autotrophic Hydrogen Bacteria  

SciTech Connect

Electrofuels Project: Ohio State is genetically modifying bacteria to efficiently convert carbon dioxide directly into butanol, an alcohol that can be used directly as a fuel blend or converted to a hydrocarbon, which closely resembles a gasoline. Bacteria are typically capable of producing a certain amount of butanol before it becomes too toxic for the bacteria to survive. Ohio State is engineering a new strain of the bacteria that could produce up to 50% more butanol before it becomes too toxic for the bacteria to survive. Finding a way to produce more butanol more efficiently would significantly cut down on biofuel production costs and help make butanol cost competitive with gasoline. Ohio State is also engineering large tanks, or bioreactors, to grow the biofuel-producing bacteria in, and they are developing ways to efficiently recover biofuel from the tanks.

None

2010-07-01

71

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

72

Production of Value-added Products by Lactic Acid Bacteria  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lactic acid bacteria (LAB) are a group of facultative anaerobic, catalase negative, nonmotile and nonsporeforming–Gram positive bacteria. Most LAB utilize high energy C sources including monomer sugars to produce energy to maintain cellular structure and function. This anaerobic fermentation proce...

73

The Genome Sequences of Cellulomonas fimi and “Cellvibrio gilvus” Reveal the Cellulolytic Strategies of Two Facultative Anaerobes, Transfer of “Cellvibrio gilvus” to the Genus Cellulomonas, and Proposal of Cellulomonas gilvus sp. nov  

PubMed Central

Actinobacteria in the genus Cellulomonas are the only known and reported cellulolytic facultative anaerobes. To better understand the cellulolytic strategy employed by these bacteria, we sequenced the genome of the Cellulomonas fimi ATCC 484T. For comparative purposes, we also sequenced the genome of the aerobic cellulolytic “Cellvibrio gilvus” ATCC 13127T. An initial analysis of these genomes using phylogenetic and whole-genome comparison revealed that “Cellvibrio gilvus” belongs to the genus Cellulomonas. We thus propose to assign “Cellvibrio gilvus” to the genus Cellulomonas. A comparative genomics analysis between these two Cellulomonas genome sequences and the recently completed genome for Cellulomonas flavigena ATCC 482T showed that these cellulomonads do not encode cellulosomes but appear to degrade cellulose by secreting multi-domain glycoside hydrolases. Despite the minimal number of carbohydrate-active enzymes encoded by these genomes, as compared to other known cellulolytic organisms, these bacteria were found to be proficient at degrading and utilizing a diverse set of carbohydrates, including crystalline cellulose. Moreover, they also encode for proteins required for the fermentation of hexose and xylose sugars into products such as ethanol. Finally, we found relatively few significant differences between the predicted carbohydrate-active enzymes encoded by these Cellulomonas genomes, in contrast to previous studies reporting differences in physiological approaches for carbohydrate degradation. Our sequencing and analysis of these genomes sheds light onto the mechanism through which these facultative anaerobes degrade cellulose, suggesting that the sequenced cellulomonads use secreted, multidomain enzymes to degrade cellulose in a way that is distinct from known anaerobic cellulolytic strategies. PMID:23342046

Bramhacharya, Shanti; Jewell, Kelsea A.; Aylward, Frank O.; Mead, David; Brumm, Phillip J.

2013-01-01

74

Impact of an aerobic thermophilic sequencing batch reactor on antibiotic-resistant anaerobic bacteria in swine waste.  

PubMed

The introduction of antibiotics to animal feed has contributed to the selection of antibiotic-resistant bacteria in concentrated animal feeding operations. The aim of this work was to characterize the impact of an aerobic thermophilic biotreatment on anaerobic antibiotic-resistant bacteria in swine waste. Despite 162- to 6,166-fold reduction in antibiotic-resistant populations enumerated in the swine waste at 25 degrees C and 37 degrees C, resistant populations remained significant (10(4) to 10(5) most probable number per milliliter) in the treated swine waste. Five resistance genes were detected before [tet(LMOS) erm(B)], and six resistance genes were detected after [tet(LMOSY) erm(B)] biotreatment. However, the biotreatment decreased the frequency of detection of resistance genes by 57%. Analysis by denaturing gradient gel electrophoresis of polymerase chain reaction-amplified 16 S ribosomal DNA (rDNA) fragments showed that the biotreatment reduced the bacterial diversity of resistant populations enumerated at 37 degrees C. Cloning and sequencing of the 16 S rDNA of these populations revealed that most clones in the treated swine waste were closely similar to some of the clones retrieved from the untreated swine waste. This study revealed that the aerobic thermophilic biotreatment developed in our laboratory does not prevent the introduction of facultatively anaerobic antibiotic-resistant bacteria and their resistance genes into agricultural ecosystems. Horizontal transfer of ecologically advantageous genes within microbial communities are likely to prevent thermophilic biotreatments from completely eliminating antibiotic-resistant bacteria and their resistance genes in animal wastes. PMID:19562247

Chénier, Martin R; Juteau, Pierre

2009-11-01

75

Synthesis and function of polyhydroxyalkanoates in anaerobic syntrophic bacteria  

SciTech Connect

Anaerobic syntrophic bacteria degrade fatty acids and some aromatic compounds which are important intermediates in the degradation of organic matter to CO{sub 2} and CH{sub 4} in methanogenic environments. Several of the described syntrophic species produce poly-{beta}-hydroxyalkanoate (PHA) suggesting that the synthesis and use of PHA is important in their physiology. In the fatty acid-degrading, syntrophic bacterium, Syntrophomonas wolfei, PHA is made during exponential phase of growth and used after growth has stopped and substrate levels are low. Altering the carbon to nitrogen ratio of the medium does not affect the amount of PHA made or its monomeric composition. It is hypothesized that PHA serves as an endogenous energy source for syntrophic bacteria when the concentrations of hydrogen or acetate are too high for the degradation of the growth substrate to be thermodynamically favorable. In S. wolfei, PHA is synthesized by two routes, the direct incorporation of 3-ketoacyl-coenzyme A (CoA) generated in {beta}-oxidation without cleavage of a C-C bond, and by the condensation and subsequent reduction of two acetyl-CoA molecules. Genes that encode for the synthesis of PHA in S. wolfei have been cloned into Escherichia coli in order to understand the molecular mechanisms that regulate PHA synthesis. 61 refs., 1 fig., 4 tabs.

McInerney, M.J.; Amos, D.A.; Kealy, K.S. [Univ. of Oklahoma, Norman, OK (United States). Dept. of Botany and Microbiology] [Univ. of Oklahoma, Norman, OK (United States). Dept. of Botany and Microbiology; Palmer, J.A. [Univ. of Oklahoma Health Sciences Center, Oklahoma City, OK (United States). Dept. of Biochemistry and Molecular Biology] [Univ. of Oklahoma Health Sciences Center, Oklahoma City, OK (United States). Dept. of Biochemistry and Molecular Biology

1992-12-31

76

Intermediary Metabolism in Protists: a Sequence-based View of Facultative Anaerobic Metabolism in Evolutionarily Diverse Eukaryotes  

PubMed Central

Protists account for the bulk of eukaryotic diversity. Through studies of gene and especially genome sequences the molecular basis for this diversity can be determined. Evident from genome sequencing are examples of versatile metabolism that go far beyond the canonical pathways described for eukaryotes in textbooks. In the last 2–3 years, genome sequencing and transcript profiling has unveiled several examples of heterotrophic and phototrophic protists that are unexpectedly well-equipped for ATP production using a facultative anaerobic metabolism, including some protists that can (Chlamydomonas reinhardtii) or are predicted (Naegleria gruberi, Acanthamoeba castellanii, Amoebidium parasiticum) to produce H2 in their metabolism. It is possible that some enzymes of anaerobic metabolism were acquired and distributed among eukaryotes by lateral transfer, but it is also likely that the common ancestor of eukaryotes already had far more metabolic versatility than was widely thought a few years ago. The discussion of core energy metabolism in unicellular eukaryotes is the subject of this review. Since genomic sequencing has so far only touched the surface of protist diversity, it is anticipated that sequences of additional protists may reveal an even wider range of metabolic capabilities, while simultaneously enriching our understanding of the early evolution of eukaryotes. PMID:21036663

Ginger, Michael L.; Fritz-Laylin, Lillian K.; Fulton, Chandler; Cande, W. Zacheus; Dawson, Scott C.

2011-01-01

77

Anaerobic degradation of benzene by marine sulfate-reducing bacteria  

NASA Astrophysics Data System (ADS)

Benzene, the archetypal aromatic hydrocarbon is a common constituent of crude oil and oil-refined products. As such, it can enter the biosphere through natural oil seeps or as a consequence of exploitation of fossil fuel reservoirs. Benzene is chemically very stable, due to the stabilizing aromatic electron system and to the lack of functional groups. Although the anaerobic degradation of benzene has been reported under denitrifying, sulfate-reducing and methanogenic conditions, the microorganisms involved and the initial biochemical steps of degradation remain insufficiently understood. Using marine sediment from a Mediterranean lagoon a sulfate-reducing enrichment culture with benzene as the sole organic substrate was obtained. Application of 16S rRNA gene-based methods showed that the enrichment was dominated (more than 85% of total cells) by a distinct phylotype affiliated with a clade of Deltaproteobacteria that include degraders of other aromatic hydrocarbons, such as naphthalene, ethylbenzene and m-xylene. Using benzoate as a soluble substrate in agar dilution series, several pure cultures closely related to Desulfotignum spp. and Desulfosarcina spp. were isolated. None of these strains was able to utilize benzene as a substrate and hybridizations with specific oligonucleotide probes showed that they accounted for as much as 6% of the total cells. Incubations with 13C-labeled benzene followed by Halogen in situ Hybridization - Secondary Ion Mass Spectroscopy (HISH-SIMS) analysis showed that cells of the dominant phylotype were highly enriched in 13C, while the accompanying bacteria had little or no 13C incorporation. These results demonstrate that the dominant phylotype was indeed the apparent benzene degrader. Dense-cell suspensions of the enrichment culture did not show metabolic activity toward added phenol or toluene, suggesting that benzene degradation did not proceed through anaerobic hydroxylation or methylation. Instead, benzoate was identified in analyses of metabolites with benzene-grown cultures, suggesting an activation of benzene via carboxylation.

Musat, Florin; Wilkes, Heinz; Musat, Niculina; Kuypers, Marcel; Widdel, Friedrich

2010-05-01

78

A dynamic estimation scheme of specific growth rates of bacteria for an anaerobic wastewater treatment process  

E-print Network

A dynamic estimation scheme of specific growth rates of bacteria for an anaerobic wastewater anal- ysis and estimation schemes for specific growth rates for an anaerobic wastewater treatment the organic and inorganic materials) of municipal or industrial wastewater often needs to be highly reduced

Paris-Sud XI, Université de

79

DESTRUCTION BY ANAEROBIC MESOPHILIC AND THERMOPHILIC DIGESTION OF VIRUSES AND INDICATOR BACTERIA INDIGENOUS TO DOMESTIC SLUDGES  

EPA Science Inventory

In raw sludges and in mesophilically and thermophilically digested anaerobic sludges, large variations in numbers of viruses occurred over narrow ranges of numbers of fecal coliforms, total coliforms, and fecal streptococci, demonstrating that the bacteria are poor quantitative r...

80

Comparative In Vitro Activities of Gemifloxacin, Other Quinolones, and Nonquinolone Antimicrobials against Obligately Anaerobic Bacteria  

Microsoft Academic Search

Gemifloxacin mesylate (SB 265805) is a fluoroquinolone with a novel oxime-derivatized pyrrolidine substituent at posi- tion C7 which is thought to confer the enhanced activity against gram-positive bacteria (11). A limited number of stud- ies have focused on its potential activity against anaerobic bacteria, demonstrating variable susceptibility patterns of the different anaerobic genera (3, 4, 7-10, 12). To further evaluate

NIELS KLEINKAUF; GRIT ACKERMANN; REINER SCHAUMANN; ARNE C. RODLOFF

2001-01-01

81

Isolation and Characterization of a Novel Facultative Anaerobic Filamentous Fungus from Japanese Rice Field Soil  

PubMed Central

A novel filamentous fungus strain designated RB-1 was isolated into pure culture from Japanese rice field soil through an anaerobic role tube technique. The strain is a mitosporic fungus that grows in both aerobic and strict anaerobic conditions using various mono-, di-, tri-, and polysaccharides with acetate and ethanol productions. The amount of acetate produced was higher than that of ethanol in both aerobic and anaerobic cultures. The characteristic verrucose or punctuate conidia of RB-1 closely resembled those of some strains of the genus Thermomyces, a thermophilic or mesophilic anamorphic ascomycete. However, based on phylogenetic analysis with the small subunit (SSU) and large subunit (LSU) rDNA sequences, RB-1 was characterized as a member of the class Lecanoromycetes of the phylum Ascomycota. Currently, RB-1 is designated as an anamorphic ascomycete and is phylogenetically considered an incertae sedis within the class Lecanoromycetes. PMID:20148171

Tonouchi, Akio

2009-01-01

82

Evaluation of the AnaeroPack system for growth of anaerobic bacteria.  

PubMed Central

Growth of anaerobic bacteria in the AnaeroPack (Mitsubishi Gas Chemical America, Inc., New York, N.Y.) anaerobic atmosphere generation systems, both the AnaeroPack jar and pouch and the AnaeroPack in a GasPak jar were considered equivalent to or better than growth obtained in the corresponding GasPak jar or pouch system (Becton Dickinson Microbiology Systems, Cockeysville, Md.) for 89 (86%) of the 103 anaerobes tested. There were a total of 26 discrepancies after 48 h of incubation, with 16 discrepancies unresolved after 96 h of incubation. The AnaeroPack jar and pouch never failed to reduce the anaerobic indicator. The AnaeroPack systems are easy to use and performed at least as well as or better than the BBL GasPak systems for growth of anaerobic bacteria. PMID:9230409

Van Horn, K G; Warren, K; Baccaglini, E J

1997-01-01

83

Carnobacterium pleistocenium sp. nov., a novel psychrotolerant, facultative anaerobe isolated from permafrost of the Fox Tunnel in Alaska  

NASA Technical Reports Server (NTRS)

A novel, psychrotolerant, facultative anaerobe, strain FTRl, was isolated from Pleistocene ice from the permafrost tunnel in Fox, Alaska. Gram-positive, motile, rod-shaped cells were observed with sizes 0(raised dot)6-0(raised dot)7 x 0(raised dot)9-1(raised dot)5 microns. Growth occurred within the pH range 6(raised dot)5-9(raised dot)5 with optimum growth at pH 7(raised dot)3-7(raised dot)5. The temperature range for growth of the novel isolate was 0-28 C and optimum growth occurred at 24 C. The novel isolate does not require NaCl; growth was observed between 0 and 5% NaCl with optimum growth at 0(raised dot)5% (w/v). The novel isolate was a catalase-negative chemoorganoheterotroph that used as substrates sugars and some products of proteolysis. The metabolic end products were acetate, ethanol and CO2. Strain FTRl was sensitive to ampicillin, tetracycline, chloramphenicol, rifampicin, kanamycin and gentamicin. 16s rRNA gene sequence analysis showed 99(raised dot)8% similarity between strain FTR1 and Carnobacterium alterfunditum, but DNA-DNA hybridization between them demonstrated 39 plus or minus 1(raised dot)5% relatedness. On the basis of genotypic and phenotypic characteristics, it is proposed that strain FTRl (= ATCC BAA-754T= JCM 12174T=CIP 108033) be assigned to the novel species Carnobacterium pleistocenium sp. nov.

Pilkuta, Elena V.; Marsic, Damien; Bej, Asim; Tang, Jane; Krader, Paul; Hoover, Richard B.

2005-01-01

84

Anaerobic oxidation of arsenite in Mono Lake water and by a facultative, arsenite-oxidizing chemoautotroph, strain MLHE-1  

USGS Publications Warehouse

Arsenite [As(III)]-enriched anoxic bottom water from Mono Lake, California, produced arsenate [As(V)] during incubation with either nitrate or nitrite. No such oxidation occurred in killed controls or in live samples incubated without added nitrate or nitrite. A small amount of biological As(III) oxidation was observed in samples amended with Fe(III) chelated with nitrolotriacetic acid, although some chemical oxidation was also evident in killed controls. A pure culture, strain MLHE-1, that was capable of growth with As(III) as its electron donor and nitrate as its electron acceptor was isolated in a defined mineral salts medium. Cells were also able to grow in nitrate-mineral salts medium by using H2 or sulfide as their electron donor in lieu of As(III). Arsenite-grown cells demonstrated dark 14CO2 fixation, and PCR was used to indicate the presence of a gene encoding ribulose-1,5-biphosphate carboxylase/oxygenase. Strain MLHE-1 is a facultative chemoautotroph, able to grow with these inorganic electron donors and nitrate as its electron acceptor, but heterotrophic growth on acetate was also observed under both aerobic and anaerobic (nitrate) conditions. Phylogenetic analysis of its 16S ribosomal DNA sequence placed strain MLHE-1 within the haloalkaliphilic Ectothiorhodospira of the ??-Proteobacteria. Arsenite oxidation has never been reported for any members of this subgroup of the Proteobacteria.

Oremland, R.S.; Hoeft, S.E.; Santini, J.M.; Bano, N.; Hollibaugh, R.A.; Hollibaugh, J.T.

2002-01-01

85

Use of Enzyme Tests in Characterization and Identification of Aerobic and Facultatively Anaerobic Gram-Positive Cocci  

PubMed Central

The contribution of enzyme tests to the accurate and rapid routine identification of gram-positive cocci is introduced. The current taxonomy of the genera of aerobic and facultatively anaerobic cocci based on genotypic and phenotypic characterization is reviewed. The clinical and economic importance of members of these taxa is briefly summarized. Tables summarizing test schemes and kits available for the identification of staphylococci, enterococci, and streptococci on the basis of general requirements, number of tests, number of taxa, test classes, and completion times are discussed. Enzyme tests included in each scheme are compared on the basis of their synthetic moiety. The current understanding of the activity of enzymes important for classification and identification of the major groups, methods of testing, and relevance to the ease and speed of identification are reviewed. Publications describing the use of different identification kits are listed, and overall identification successes and problems are discussed. The relationships between the results of conventional biochemical and rapid enzyme tests are described and considered. The use of synthetic substrates for the detection of glycosidases and peptidases is reviewed, and the advantages of fluorogenic synthetic moieties are discussed. The relevance of enzyme tests to accurate and meaningful rapid routine identification is discussed. PMID:9564566

Bascomb, Shoshana; Manafi, Mammad

1998-01-01

86

Behavior of plutonium interacting with bentonite and sulfate-reducing anaerobic bacteria  

SciTech Connect

The interactions between sulfate reducing anaerobic bacteria and plutonium, with or without bentonite present, were investigated using distribution coefficients [Kd (ml/g)] as an index of the radionuclide behavior. Plutonium Kds for living bacteria varied within a large range, from 1,804 to 112,952, depending on the pH, while the Kds ranged from 1,180 to 5,931 for dead bacteria. In general, living bacteria had higher plutonium Kds than dead bacteria. Furthermore, the higher Kd values of 39,677 to 106,915 for living bacteria were obtained for a pH range between 6.83 and 8.25, while no visible pH effect was observed for dead bacteria. These Kd values were obtained using tracers for both {sup 236}Pu and {sup 239}Pu, which can check the experimental procedures and mass balance. Another comparison was conducted for plutonium Kd values of mixtures of living bacteria with bentonite and sterilized bacteria with bentonite. The range of Kd values for the non-sterilized bacteria with bentonite were 1,194 to 83,648 while Kd values for the sterilized bacteria with bentonite were from 624 to 17,236. Again, the Kd values for the living bacteria with bentonite were higher than those of sterilized bacteria with bentonite. In other words, the presence of living anaerobic bacteria with bentonite increased, by roughly 50 times, the Kd values of {sup 239}Pu when compared to the mixture of dead bacteria with bentonite. The results indicate that the effects of anaerobic bacteria within the engineered barrier system (in this case bentonite) will play a significant role in the behavior of plutonium in geologic repositories.

Kudo, A.; Zheng, J.; Cayer, I. [National Research Council of Canada, Ottawa, Ontario (Canada); Fujikawa, Y. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Asano, H.; Arai, K. [Ishikawajima-Harima Heavy Industries Co. Ltd., Isogo, Yokohama (Japan); Yoshikawa, H.; Ito, M. [Power Reactor and Nuclear Fuel Development Co., Tokai, Ibaraki (Japan)

1997-12-31

87

Antimicrobial susceptibility of clinically isolated anaerobic bacteria in a University Hospital Centre Split, Croatia in 2013.  

PubMed

Anaerobic bacteria play a significant role in many endogenous polymicrobial infections. Since antimicrobial resistance among anaerobes has increased worldwide, it is useful to provide local susceptibility data to guide empirical therapy. The present study reports recent data on the susceptibility of clinically relevant anaerobes in a University Hospital Centre (UHC) Split, Croatia. A total of 63 Gram-negative and 59 Gram-positive anaerobic clinical isolates from various body sites were consecutively collected from January to December 2013. Antimicrobial susceptibility testing was performed using standardized methods and interpreted using EUCAST criteria. Patient's clinical and demographic data were recorded by clinical microbiologist. Among 35 isolates of Bacteroides spp., 97.1% were resistant to penicillin (PCN), 5.7% to amoxicillin/clavulanic acid (AMC), 8.6% to piperacillin/tazobactam (TZP), 29.0% to clindamycin (CLI) and 2.9% to metronidazole (MZ). Percentages of susceptible strains to imipenem (IPM), meropenem (MEM) and ertapenem (ETP) were 94.3. Resistance of other Gram-negative bacilli was 76.0% to PCN, 8.0% to AMC, 12.0% to TZP, 28.0% to CLI and 8% to MZ. All other Gram-negative strains were fully susceptible to MEM and ETP, while 96.0% were susceptible to IPM. Clostridium spp. isolates were 100% susceptible to all tested antibiotics except to CLI (two of four tested isolates were resistant). Propionibacterium spp. showed resistance to CLI in 4.3%, while 100% were resistant to MZ. Among other Gram-positive bacilli, 18.2% were resistant to PCN, 9.1% to CLI and 54.5% to MZ, while 81.8% of isolates were susceptible to carbapenems. Gram-positive cocci were 100% susceptible to all tested antimicrobials except to MZ, where 28.6% of resistant strains were recorded. Abdomen was the most common source of isolates (82.5%). The most prevalent types of infection were abscess (22.1%), sepsis (14.8%), appendicitis (13.9%) and peritonitis (6.6%). Twenty four patients (19.7%) received empiric antimicrobial therapy. One hundred and one patients (82.8%) had polymicrobial aerobic/anaerobic isolates cultivated from the same specimens. Almost all aerobic bacteria were of endogenous origin and showed fully susceptible antimicrobial profile; only 8.7% (9/104) were multiresistant and considered as hospital acquired. Based on our findings, ?-lactam/?-lactamase inhibitor combinations and metronidazole remain useful antimicrobials for empiric treatment of anaerobic infections, while carbapenems should be reserved for situations were multidrug resistant, aerobic or facultative Gram-negative bacteria are expected. However, a certain percentage of resistant isolates were observed for each of these agents. Therefore, periodic resistance surveillance in anaerobes is highly recommended in order to guide empirical therapy. PMID:25479237

Novak, Anita; Rubic, Zana; Dogas, Varja; Goic-Barisic, Ivana; Radic, Marina; Tonkic, Marija

2015-02-01

88

Population Genomics of the Facultatively Mutualistic Bacteria Sinorhizobium meliloti and S. medicae  

PubMed Central

The symbiosis between rhizobial bacteria and legume plants has served as a model for investigating the genetics of nitrogen fixation and the evolution of facultative mutualism. We used deep sequence coverage (>100×) to characterize genomic diversity at the nucleotide level among 12 Sinorhizobium medicae and 32 S. meliloti strains. Although these species are closely related and share host plants, based on the ratio of shared polymorphisms to fixed differences we found that horizontal gene transfer (HGT) between these species was confined almost exclusively to plasmid genes. Three multi-genic regions that show the strongest evidence of HGT harbor genes directly involved in establishing or maintaining the mutualism with host plants. In both species, nucleotide diversity is 1.5–2.5 times greater on the plasmids than chromosomes. Interestingly, nucleotide diversity in S. meliloti but not S. medicae is highly structured along the chromosome – with mean diversity (??) on one half of the chromosome five times greater than mean diversity on the other half. Based on the ratio of plasmid to chromosome diversity, this appears to be due to severely reduced diversity on the chromosome half with less diversity, which is consistent with extensive hitchhiking along with a selective sweep. Frequency-spectrum based tests identified 82 genes with a signature of adaptive evolution in one species or another but none of the genes were identified in both species. Based upon available functional information, several genes identified as targets of selection are likely to alter the symbiosis with the host plant, making them attractive targets for further functional characterization. PMID:22876202

Epstein, Brendan; Branca, Antoine; Mudge, Joann; Bharti, Arvind K.; Briskine, Roman; Farmer, Andrew D.; Sugawara, Masayuki; Young, Nevin D.; Sadowsky, Michael J.; Tiffin, Peter

2012-01-01

89

Population genomics of the facultatively mutualistic bacteria Sinorhizobium meliloti and S. medicae.  

PubMed

The symbiosis between rhizobial bacteria and legume plants has served as a model for investigating the genetics of nitrogen fixation and the evolution of facultative mutualism. We used deep sequence coverage (>100×) to characterize genomic diversity at the nucleotide level among 12 Sinorhizobium medicae and 32 S. meliloti strains. Although these species are closely related and share host plants, based on the ratio of shared polymorphisms to fixed differences we found that horizontal gene transfer (HGT) between these species was confined almost exclusively to plasmid genes. Three multi-genic regions that show the strongest evidence of HGT harbor genes directly involved in establishing or maintaining the mutualism with host plants. In both species, nucleotide diversity is 1.5-2.5 times greater on the plasmids than chromosomes. Interestingly, nucleotide diversity in S. meliloti but not S. medicae is highly structured along the chromosome - with mean diversity (?(?)) on one half of the chromosome five times greater than mean diversity on the other half. Based on the ratio of plasmid to chromosome diversity, this appears to be due to severely reduced diversity on the chromosome half with less diversity, which is consistent with extensive hitchhiking along with a selective sweep. Frequency-spectrum based tests identified 82 genes with a signature of adaptive evolution in one species or another but none of the genes were identified in both species. Based upon available functional information, several genes identified as targets of selection are likely to alter the symbiosis with the host plant, making them attractive targets for further functional characterization. PMID:22876202

Epstein, Brendan; Branca, Antoine; Mudge, Joann; Bharti, Arvind K; Briskine, Roman; Farmer, Andrew D; Sugawara, Masayuki; Young, Nevin D; Sadowsky, Michael J; Tiffin, Peter

2012-01-01

90

The Genome Sequence of the Obligately Chemolithoautotrophic, Facultatively Anaerobic Bacterium Thiobacillus denitrificans  

PubMed Central

The complete genome sequence of Thiobacillus denitrificans ATCC 25259 is the first to become available for an obligately chemolithoautotrophic, sulfur-compound-oxidizing, ?-proteobacterium. Analysis of the 2,909,809-bp genome will facilitate our molecular and biochemical understanding of the unusual metabolic repertoire of this bacterium, including its ability to couple denitrification to sulfur-compound oxidation, to catalyze anaerobic, nitrate-dependent oxidation of Fe(II) and U(IV), and to oxidize mineral electron donors. Notable genomic features include (i) genes encoding c-type cytochromes totaling 1 to 2 percent of the genome, which is a proportion greater than for almost all bacterial and archaeal species sequenced to date, (ii) genes encoding two [NiFe]hydrogenases, which is particularly significant because no information on hydrogenases has previously been reported for T. denitrificans and hydrogen oxidation appears to be critical for anaerobic U(IV) oxidation by this species, (iii) a diverse complement of more than 50 genes associated with sulfur-compound oxidation (including sox genes, dsr genes, and genes associated with the AMP-dependent oxidation of sulfite to sulfate), some of which occur in multiple (up to eight) copies, (iv) a relatively large number of genes associated with inorganic ion transport and heavy metal resistance, and (v) a paucity of genes encoding organic-compound transporters, commensurate with obligate chemolithoautotrophy. Ultimately, the genome sequence of T. denitrificans will enable elucidation of the mechanisms of aerobic and anaerobic sulfur-compound oxidation by ?-proteobacteria and will help reveal the molecular basis of this organism's role in major biogeochemical cycles (i.e., those involving sulfur, nitrogen, and carbon) and groundwater restoration. PMID:16452431

Beller, Harry R.; Chain, Patrick S. G.; Letain, Tracy E.; Chakicherla, Anu; Larimer, Frank W.; Richardson, Paul M.; Coleman, Matthew A.; Wood, Ann P.; Kelly, Donovan P.

2006-01-01

91

Phylogenetic and functional diversity of propionate-oxidizing bacteria in an anaerobic digester sludge  

Microsoft Academic Search

The phylogenetic and functional diversity of syntrophic propionate-oxidizing bacteria (POB) present in an anaerobic digester\\u000a was investigated by microautoradiography combined with fluorescent in situ hybridization (MAR–FISH) that can directly link\\u000a 16S rRNA phylogeny with in situ metabolic function. The syntrophic POB community in the anaerobic digester sludge consisted\\u000a of at least four phylogenetic groups: Syntrophobacter, uncultured short rod Smithella (Smithella

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

2007-01-01

92

Anaerobic oxidation of hydrocarbons in crude oil by new types of sulphate-reducing bacteria  

Microsoft Academic Search

MANY crude oil constituents are biodegradable in the presence of oxygen; however, a substantial anaerobic degradation has never been demonstrated1,2. An unusually low content of n-alkanes in oils of certain deposits is commonly attributed to selective utilization of these hydrocarbons by aerobic microorganisms3,4. On the other hand, oil wells and production fluids were shown to harbour anaerobic sulphate-reducing bacteria5-8, but

Petra Rueter; Ralf Rabus; Heinz Wilkest; Frank Aeckersberg; Fred A. Rainey; Holger W. Jannasch; Friedrich Widdel

1994-01-01

93

Trichococcus Patagoniensis sp. nov., a Facultative Anaerobe that grows at -5 C, Isolated from Penguin Guano in Chilean Patagonia  

NASA Technical Reports Server (NTRS)

A novel, extremely psychrotolerant, facultative anaerobe, strain PmagGl(sup T), was isolated from guano of Magellanic penguins (Spheniscus magellanicus) collected in Chilean Patagonia. Gram-variable, motile cocci with a diameter of 1.3-2.0 micrometers were observed singularly or in pairs, short chains and irregular conglomerates. Growth occurred within the pH range 6.0-10.0, with optimum growth at pH 8.5. The temperature range for growth of the novel isolate was from -5 to 35 C, with optimum growth at 28-30 C. Strain PmagG1(sup T) did not require NaCl, as growth was observed in the presence of 0-6.5% NaCl with optimum growth at 0.5% (w/v). Strain PmagGl(sup T) was a catalase-negative chemo-organoheterotroph that used sugars and some organic acids as substrates. The metabolic end products were lactate, formate, acetate, ethanol and Con. Strain PmagG1(sup T) was sensitive to ampicillin, tetracycline, chloramphenicol, rifampicin, kanamycin and gentamicin. The G+C content of its genomic DNA was 45.8 mol%. 16S rRNA gene sequence analysis showed 100 % similarity of strain PmagG1(sup T) with Trichococcus collinsii ATCC BAA-296(sup T), but DNA-DNA hybridization between them demonstrated relatedness values of less than 45 plus or minus 1%. Another phylogenetically closely related species, Trichococcus pasteurii, showed 99.85 % similarity by 16s rRNA sequencing and DNA-DNA hybridization showed relatedness values of 47 plus or minus 1.5%. Based on genotypic and phenotypic characteristics, the novel species Trichococcus patagoniensis sp. nov. is proposed, with strain PmagG1(sup T) (=ATCC BAA-756(sup T)=JCM 12176(sup T)=CIP 108035(sup T)) as the type strain.

Pikuta, Elena V.; Hoover, Richard B.; Bej, Asim K.; Marsic, Damien; Whitman, William B.; Krader, Paul E.; Tang, Jane

2006-01-01

94

Complete genome sequence of the facultatively anaerobic, appendaged bacterium Muricauda ruestringensis type strain (B1T)  

SciTech Connect

Muricauda ruestringensis Bruns et al. 2001 is the type species of the genus Muricauda, which belongs to the family Flavobacteriaceae in the phylum Bacteroidetes. The species is of interest because of its isolated position in the genomically unexplored genus Muricauda, which is located in a part of the tree of life containing not many organisms with sequenced genomes. The genome, which consists of a circular chromosome of 3,842,422 bp length with a total of 3,478 protein-coding and 47 RNA genes, is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Teshima, Hazuki [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Pan, Chongle [ORNL; Brambilla, Evelyne-Marie [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute

2012-01-01

95

Bacteria associated with deep, alkaline, anaerobic groundwaters in Southeast Washington  

Microsoft Academic Search

The microbial diversity in two deep, confined aquifers, the Grande Ronde (1270 m) and the Priest Rapids (316 m), Hanford Reservation, Washington, USA, was investigated by sampling from artesian wells. These basaltic aquifers were alkaline (pH 8.5 to 10.5) and anaerobic (Eh -200 to -450 mV). The wells were allowed to free-flow until pH and Eh stabilized, then the microflora

T. O. Stevens; J. P. McKinley; J. K. Fredrickson

1993-01-01

96

Thermophilic biodegradation of BTEX by two consortia of anaerobic bacteria  

Microsoft Academic Search

Two thermophilic anaerobic bacterial consortia (ALK-1 and LLNL-1), capable of degrading the aromatic fuel hydrocarbons, benzene,\\u000a toluene, ethylbenzene, and the xylenes (BTEX compounds), were developed at 60?C from the produced water of ARCO'S Kuparuk\\u000a oil field at Alaska and the subsurface water at the Lawrence Livermore National Laboratory gasoline-spill site, respectively.\\u000a Both consortia were found to grow at 45–75?C on

C.-I. Chen; R. T. Taylor

1997-01-01

97

Degradation of BTEX by anaerobic bacteria: physiology and application  

Microsoft Academic Search

Pollution of the environment with aromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX)\\u000a is often observed. The cleanup of these toxic compounds has gained much attention in the last decades. In situ bioremediation\\u000a of aromatic hydrocarbons contaminated soils and groundwater by naturally occurring microorganisms or microorganisms that are\\u000a introduced is possible. Anaerobic bioremediation is an attractive technology

Sander A. B. Weelink; Miriam H. A. van Eekert; Alfons J. M. Stams

2010-01-01

98

Understanding how commensal obligate anaerobic bacteria regulate immune functions in the large intestine.  

PubMed

The human gastrointestinal tract is colonised by trillions of commensal bacteria, most of which are obligate anaerobes residing in the large intestine. Appropriate bacterial colonisation is generally known to be critical for human health. In particular, the development and function of the immune system depends on microbial colonisation, and a regulated cross-talk between commensal bacteria, intestinal epithelial cells and immune cells is required to maintain mucosal immune homeostasis. This homeostasis is disturbed in various inflammatory disorders, such as inflammatory bowel diseases. Several in vitro and in vivo studies indicate a role for Faecalibacterium prausnitzii, Bacteroides thetaiotaomicron, Bacteroides fragilis, Akkermansia muciniphila and segmented filamentous bacteria in maintaining intestinal immune homeostasis. These obligate anaerobes are abundant in the healthy intestine but reduced in several inflammatory diseases, suggesting an association with protective effects on human health. However, knowledge of the mechanisms underlying the effects of obligate anaerobic intestinal bacteria remains limited, in part due to the difficulty of co-culturing obligate anaerobes together with oxygen-requiring human epithelial cells. By using novel dual-environment co-culture models, it will be possible to investigate the effects of the unstudied majority of intestinal microorganisms on the human epithelia. This knowledge will provide opportunities for improving human health and reducing the risk of inflammatory diseases. PMID:25545102

Maier, Eva; Anderson, Rachel C; Roy, Nicole C

2015-01-01

99

Anaerobic oxidation of thiosulfate to tetrathionate by obligately heterotrophic bacteria, belonging to the Pseudomonas stutzeri group  

Microsoft Academic Search

A number of strains of heterotrophic bacteria were isolated from various environments on the basis of their potential to oxidize inorganic sulfur compounds to tetrathionate. The isolates were screened for the ability to oxidize thiosulfate under denitrifying conditions. Many of them could grow anaerobically with acetate and nitrate, and eight strains could oxidize thiosulfate to tetrathionate under the same conditions.

Dimitry Yu. Sorokin; Andreas Teske; Lesley A. Robertson; J. Gijs Kuenen

1999-01-01

100

Population dynamics of propionate-oxidizing bacteria under methanogenic and sulfidogenic conditions in anaerobic granular sludge.  

PubMed Central

Laboratory-scale upflow anaerobic sludge-bed reactors were inoculated with industrial granular sludge and fed with either propionate or propionate and sulfate. The population dynamics of the propionate-oxidizing bacteria Desulfobulbus sp. and the syntrophically growing strain SYN7 were studied in reactors by dot blot and in situ hybridization with 16S rRNA-based oligonucleotide probes. PMID:8787413

Harmsen, H J; Akkermans, A D; Stams, A J; de Vos, W M

1996-01-01

101

Understanding How Commensal Obligate Anaerobic Bacteria Regulate Immune Functions in the Large Intestine  

PubMed Central

The human gastrointestinal tract is colonised by trillions of commensal bacteria, most of which are obligate anaerobes residing in the large intestine. Appropriate bacterial colonisation is generally known to be critical for human health. In particular, the development and function of the immune system depends on microbial colonisation, and a regulated cross-talk between commensal bacteria, intestinal epithelial cells and immune cells is required to maintain mucosal immune homeostasis. This homeostasis is disturbed in various inflammatory disorders, such as inflammatory bowel diseases. Several in vitro and in vivo studies indicate a role for Faecalibacterium prausnitzii, Bacteroides thetaiotaomicron, Bacteroides fragilis, Akkermansia muciniphila and segmented filamentous bacteria in maintaining intestinal immune homeostasis. These obligate anaerobes are abundant in the healthy intestine but reduced in several inflammatory diseases, suggesting an association with protective effects on human health. However, knowledge of the mechanisms underlying the effects of obligate anaerobic intestinal bacteria remains limited, in part due to the difficulty of co-culturing obligate anaerobes together with oxygen-requiring human epithelial cells. By using novel dual-environment co-culture models, it will be possible to investigate the effects of the unstudied majority of intestinal microorganisms on the human epithelia. This knowledge will provide opportunities for improving human health and reducing the risk of inflammatory diseases. PMID:25545102

Maier, Eva; Anderson, Rachel C.; Roy, Nicole C.

2014-01-01

102

Role of anaerobic bacteria in the metabolic welfare of the colonic mucosa in man  

Microsoft Academic Search

Suspensions of isolated epithelial cells (colonocytes) from the human colon were used to assess utilisation of respiratory fuels which are normally available to the colonic mucosa in vivo. Cells were prepared from operative specimens of the ascending colon (seven) and descending colon (seven). The fuels that were used were the short chain fatty acid n-butyrate, produced only by anaerobic bacteria

W E Roediger

1980-01-01

103

Evaluation of AnaeroGen system for growth of anaerobic bacteria.  

PubMed Central

The Oxoid AnaeroGen system was compared with the BBL GasPak for the production of an anaerobic atmosphere and was evaluated for its ability to support the growth of 135 clinically significant anaerobic bacteria. An anaerobe chamber was used as the "gold standard" for supporting the growth of anaerobes. The AnaeroGen requires no catalyst, produces no hydrogen, requires no water, and reduces preparation time to a minimum. The water-activated BBL GasPak generates hydrogen. For 132 of the 135 strains tested, better initial growth at 48 h was noted for the jar methods than for the anaerobe chamber. At 72 h, 113 of the 135 strains showed equal growth, and at 7 days, only marginal differences in growth patterns were noted. The AnaeroGen never failed to reduce the anaerobic indicator, while the BBL GasPak occasionally failed to do so. The AnaeroGen performed at least as well as, and sometimes better than, the established methods. The AnaeroGen is a good alternative for use in anaerobic jars. PMID:7494033

Miller, P H; Wiggs, L S; Miller, J M

1995-01-01

104

Decrease of U(VI) Immobilization Capability of the Facultative Anaerobic Strain Paenibacillus sp. JG-TB8 under Anoxic Conditions Due to Strongly Reduced Phosphatase Activity  

PubMed Central

Interactions of a facultative anaerobic bacterial isolate named Paenibacillus sp. JG-TB8 with U(VI) were studied under oxic and anoxic conditions in order to assess the influence of the oxygen-dependent cell metabolism on microbial uranium mobilization and immobilization. We demonstrated that aerobically and anaerobically grown cells of Paenibacillus sp. JG-TB8 accumulate uranium from aqueous solutions under acidic conditions (pH 2 to 6), under oxic and anoxic conditions. A combination of spectroscopic and microscopic methods revealed that the speciation of U(VI) associated with the cells of the strain depend on the pH as well as on the aeration conditions. At pH 2 and pH 3, uranium was exclusively bound by organic phosphate groups provided by cellular components, independently on the aeration conditions. At higher pH values, a part (pH 4.5) or the total amount (pH 6) of the dissolved uranium was precipitated under oxic conditions in a meta-autunite-like uranyl phosphate mineral phase without supplying an additional organic phosphate substrate. In contrast to that, under anoxic conditions no mineral formation was observed at pH 4.5 and pH 6, which was clearly assigned to decreased orthophosphate release by the cells. This in turn was caused by a suppression of the indigenous phosphatase activity of the strain. The results demonstrate that changes in the metabolism of facultative anaerobic microorganisms caused by the presence or absence of oxygen can decisively influence U(VI) biomineralization. PMID:25157416

Reitz, Thomas; Rossberg, Andre; Barkleit, Astrid; Selenska-Pobell, Sonja; Merroun, Mohamed L.

2014-01-01

105

In Vitro Activities of OPT-80 and Comparator Drugs against Intestinal Bacteria  

PubMed Central

The activities of OPT-80 against 453 intestinal bacteria were compared with those of seven other drugs. OPT-80 showed good activity against most clostridia, staphylococci, and enterococci, but streptococci, aerobic and facultative gram-negative rods, anaerobic gram-negative rods, and Clostridium ramosum were resistant. Poor activity against anaerobic gram-negative rods may maintain colonization resistance. PMID:15561877

Finegold, Sydney M.; Molitoris, Denise; Vaisanen, Marja-Liisa; Song, Yuli; Liu, Chengxu; Bolaños, Mauricio

2004-01-01

106

Frequency of resistance in obligate anaerobic bacteria isolated from dogs, cats, and horses to antimicrobial agents.  

PubMed

Clinical specimens from dogs, cats, and horses were examined for the presence of obligate anaerobic bacteria. Of 4,018 specimens cultured, 368 yielded 606 isolates of obligate anaerobic bacteria (248 from dogs, 50 from cats, and 308 from horses). There were 100 specimens from 94 animals from which only anaerobes were isolated (25 dogs, 8 cats, and 61 horses). The most common sites tested were abdominal fluid (dogs and cats) and intestinal contents (horses). The most common microorganism isolated from dogs, cats, and horses was Clostridium perfringens (75, 13, and101 isolates, respectively). The MICs of amoxicillin with clavulanate, ampicillin, chloramphenicol, metronidazole, and penicillin were determined using a gradient endpoint method for anaerobes. Isolates collected at necropsy were not tested for antimicrobial susceptibility unless so requested by the clinician. There were 1/145 isolates tested that were resistant to amoxicillin-clavulanate (resistance breakpoint ? 16/8 ?g/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ? 2 ?g/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ? 32 ?g/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ? 8 ?g/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ? 32 ?g/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ? 2 ?g/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugs in vitro. PMID:24025899

Lawhon, S D; Taylor, A; Fajt, V R

2013-11-01

107

Frequency of Resistance in Obligate Anaerobic Bacteria Isolated from Dogs, Cats, and Horses to Antimicrobial Agents  

PubMed Central

Clinical specimens from dogs, cats, and horses were examined for the presence of obligate anaerobic bacteria. Of 4,018 specimens cultured, 368 yielded 606 isolates of obligate anaerobic bacteria (248 from dogs, 50 from cats, and 308 from horses). There were 100 specimens from 94 animals from which only anaerobes were isolated (25 dogs, 8 cats, and 61 horses). The most common sites tested were abdominal fluid (dogs and cats) and intestinal contents (horses). The most common microorganism isolated from dogs, cats, and horses was Clostridium perfringens (75, 13, and101 isolates, respectively). The MICs of amoxicillin with clavulanate, ampicillin, chloramphenicol, metronidazole, and penicillin were determined using a gradient endpoint method for anaerobes. Isolates collected at necropsy were not tested for antimicrobial susceptibility unless so requested by the clinician. There were 1/145 isolates tested that were resistant to amoxicillin-clavulanate (resistance breakpoint ? 16/8 ?g/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ? 2 ?g/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ? 32 ?g/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ? 8 ?g/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ? 32 ?g/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ? 2 ?g/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugs in vitro. PMID:24025899

Taylor, A.; Fajt, V. R.

2013-01-01

108

Multi-centre evaluation of mass spectrometric identification of anaerobic bacteria using the VITEK® MS system.  

PubMed

Accurate and timely identification of anaerobic bacteria is critical to successful treatment. Classic phenotypic methods for identification require long turnaround times and can exhibit poor species level identification. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an identification method that can provide rapid identification of anaerobes. We present a multi-centre study assessing the clinical performance of the VITEK(®) MS in the identification of anaerobic bacteria. Five different test sites analysed a collection of 651 unique anaerobic isolates comprising 11 different genera. Multiple species were included for several of the genera. Briefly, anaerobic isolates were applied directly to a well of a target plate. Matrix solution (?-cyano-4-hydroxycinnamic acid) was added and allowed to dry. Mass spectra results were generated with the VITEK(®) MS, and the comparative spectral analysis and organism identification were determined using the VITEK(®) MS database 2.0. Results were confirmed by 16S rRNA gene sequencing. Of the 651 isolates analysed, 91.2% (594/651) exhibited the correct species identification. An additional eight isolates were correctly identified to genus level, raising the rate of identification to 92.5%. Genus-level identification consisted of Actinomyces, Bacteroides and Prevotella species. Fusobacterium nucleatum, Actinomyces neuii and Bacteroides uniformis were notable for an increased percentage of no-identification results compared with the other anaerobes tested. VITEK(®) MS identification of clinically relevant anaerobes is highly accurate and represents a dramatic improvement over other phenotypic methods in accuracy and turnaround time. PMID:23927597

Garner, O; Mochon, A; Branda, J; Burnham, C-A; Bythrow, M; Ferraro, M; Ginocchio, C; Jennemann, R; Manji, R; Procop, G W; Richter, S; Rychert, J; Sercia, L; Westblade, L; Lewinski, M

2014-04-01

109

In Vitro Activity of Ceftaroline against 623 Diverse Strains of Anaerobic Bacteria ?  

PubMed Central

The in vitro activities of ceftaroline, a novel, parenteral, broad-spectrum cephalosporin, and four comparator antimicrobials were determined against anaerobic bacteria. Against Gram-positive strains, the activity of ceftaroline was similar to that of amoxicillin-clavulanate and four to eight times greater than that of ceftriaxone. Against Gram-negative organisms, ceftaroline showed good activity against ?-lactamase-negative strains but not against the members of the Bacteroides fragilis group. Ceftaroline showed potent activity against a broad spectrum of anaerobes encountered in respiratory, skin, and soft tissue infections. PMID:20100877

Citron, D. M.; Tyrrell, K. L.; Merriam, C. V.; Goldstein, E. J. C.

2010-01-01

110

Removal Of Heavy Metals From Electroplating Wastewater By Anaerobic Bacteria  

NASA Astrophysics Data System (ADS)

Biosorption of heavy metals from simulated wastewater and the raw electroplating wastewater with "BM (Biosorption of Metals) bacteria" were investigated in this study. The influence of initial pH, biosorbents dose, concentration of ions, contact time and temperature on biosorption capacity of Cr(VI) and Ni(II) were studied. The optimum pH for biosorption of Cr(VI) was found to be low, and the removal efficiency of Cr(VI) was 98.60% with "BM bacteria" at pH 2. The removal efficiency of Ni(II) was increased with increasing the pH, and was enhanced up to 115% compared with the wastewater without BM bacteria. In this experiment, the "BM bacteria" efficiently removed Cu(II), Ni(II), Cr(VI), Zn(II) and COD from the raw electroplating wastewater, and the removal efficiencies were 98.92%, 99.92%, 99.86%, 99.93% and 45.20% respectively.

Ma, Wanggang; Sun, Peide; Song, Yingqi; Zhang, Yi; Yin, Jun

2010-11-01

111

Routine Testing for Anaerobic Bacteria in Cerebrospinal Fluid Cultures Improves Recovery of Clinically Significant Pathogens  

PubMed Central

In North America, the widespread use of vaccines targeting Haemophilus influenzae type b and Streptococcus pneumoniae have dramatically altered the epidemiology of bacterial meningitis, while the methodology for culturing cerebrospinal fluid (CSF) specimens has remained largely unchanged. The aims of this study were 2-fold: to document the current epidemiology of bacterial meningitis at a tertiary care medical center and to assess the clinical utility of routinely querying for anaerobes in CSF cultures. To that end, we assessed CSF cultures submitted over a 2-year period. A brucella blood agar (BBA) plate, incubated anaerobically for 5 days, was included in the culture procedure for all CSF specimens during the second year of evaluation. In the pre- and postimplementation years, 2,353 and 2,302 CSF specimens were cultured, with 49 and 99 patients having positive culture results, respectively. The clinical and laboratory data for patients with positive cultures were reviewed. Anaerobic bacteria were isolated in the CSF samples from 33 patients post-BBA compared to two patients pre-BBA (P = 0.01). The anaerobic isolates included Bacteroides thetaiotaomicron (n = 1), Propionibacterium species (n = 15), and Propionibacterium acnes (n = 19) isolates; all of these isolates were recovered on the BBA. Eight of the 35 patients from whom anaerobic organisms were isolated received antimicrobial therapy. Although six of these patients had central nervous system hardware, two patients did not have a history of a neurosurgical procedure and had community-acquired anaerobic bacterial meningitis. This study demonstrates that the simple addition of an anaerobically incubated BBA to the culture of CSF specimens enhances the recovery of clinically significant anaerobic pathogens. PMID:24622102

Pittman, Meredith E.; Thomas, Benjamin S.; Wallace, Meghan A.; Weber, Carol J.

2014-01-01

112

Propionate Oxidation by and Methanol Inhibition of Anaerobic Ammonium-Oxidizing Bacteria  

PubMed Central

Anaerobic ammonium oxidation (anammox) is a recently discovered microbial pathway and a cost-effective way to remove ammonium from wastewater. Anammox bacteria have been described as obligate chemolithoautotrophs. However, many chemolithoautotrophs (i.e., nitrifiers) can use organic compounds as a supplementary carbon source. In this study, the effect of organic compounds on anammox bacteria was investigated. It was shown that alcohols inhibited anammox bacteria, while organic acids were converted by them. Methanol was the most potent inhibitor, leading to complete and irreversible loss of activity at concentrations as low as 0.5 mM. Of the organic acids acetate and propionate, propionate was consumed at a higher rate (0.8 nmol min?1 mg of protein?1) by Percoll-purified anammox cells. Glucose, formate, and alanine had no effect on the anammox process. It was shown that propionate was oxidized mainly to CO2, with nitrate and/or nitrite as the electron acceptor. The anammox bacteria carried out propionate oxidation simultaneously with anaerobic ammonium oxidation. In an anammox enrichment culture fed with propionate for 150 days, the relative amounts of anammox cells and denitrifiers did not change significantly over time, indicating that anammox bacteria could compete successfully with heterotrophic denitrifiers for propionate. In conclusion, this study shows that anammox bacteria have a more versatile metabolism than previously assumed. PMID:15691967

Güven, Didem; Dapena, Ana; Kartal, Boran; Schmid, Markus C.; Maas, Bart; van de Pas-Schoonen, Katinka; Sozen, Seval; Mendez, Ramon; Op den Camp, Huub J. M.; Jetten, Mike S. M.; Strous, Marc; Schmidt, Ingo

2005-01-01

113

Isolation and Partial Characterization of Bacteria in an Anaerobic Consortium That Mineralizes 3-Chlorobenzoic Acid †  

PubMed Central

A methanogenic consortium able to use 3-chlorobenzoic acid as its sole energy and carbon source was enriched from anaerobic sewage sludge. Seven bacteria were isolated from the consortium in mono- or coculture. They included: one dechlorinating bacterium (strain DCB-1), one benzoate-oxidizing bacterium (strain BZ-2), two butyrate-oxidizing bacteria (strains SF-1 and NSF-2), two H2-consuming methanogens (Methanospirillum hungatei PM-1 and Methanobacterium sp. strain PM-2), and a sulfate-reducing bacterium (Desulfovibrio sp. strain PS-1). The dechlorinating bacterium (DCB-1) was a gram-negative, obligate anaerobe with a unique “collar” surrounding the cell. A medium containing rumen fluid supported minimal growth; pyruvate was the only substrate found to increase growth. The bacterium had a generation time of 4 to 5 days. 3-Chlorobenzoate was dechlorinated stoichiometrically to benzoate, which accumulated in the medium; the rate of dechlorination was ca. 0.1 pmol bacterium?1 day?1. The benzoate-oxidizing bacterium (BZ-2) was a gram-negative, obligate anaerobe and could only be grown as a syntroph. Benzoate was the only substrate observed to support growth, and, when grown in coculture with M. hungatei, it was fermented to acetate and CH4. One butyrate-oxidizing bacterium (NSF-2) was a gram-negative, non-sporeforming, obligate anaerobe; the other (SF-1) was a gram-positive, sporeforming, obligate anaerobe. Both could only be grown as syntrophs. The substrates observed to support growth of both bacteria were butyrate, 2-dl-methylbutyrate, valerate, and caproate; isobutyrate supported growth of only the sporeforming bacterium (SF-1). Fermentation products were acetate and CH4 (from butyrate, isobutyrate, or caproate) or acetate, propionate, and CH4 (from 2-dl-methylbutyrate or valerate) when grown in coculture with M. hungatei. A mutualism among at least the dechlorinating, benzoate-oxidizing, and methane-forming members was apparently required for utilization of the 3-chlorobenzoate substrate. Images PMID:16346648

Shelton, Daniel R.; Tiedje, James M.

1984-01-01

114

Isolation and partial characterization of bacteria in an anaerobic consortium that mineralizes 3-chlorobenzoic acid  

SciTech Connect

A methanogenic consortium able to use 3-chlorobenzoic acid as its sole energy and carbon source was enriched from anaerobic sewage sludge. Seven bacteria were isolated from the consortium in mono- or coculture. They included: one dechlorinating bacterium, one benzoate-oxidizing bacterium, two butyrate-oxidizing bacteria, two H/sub 2/-consuming methanogens (methanospirillum hungatei PM-1 and Methanobacterium sp. strain PM-2), and a sulfate-reducing bacterium (Desulfovibrio sp.). The dechlorinating bacterium was a gram-negative, obligate anaerobe with a unique collar surrounding the cell. A medium containing rumen fluid supported minimal growth; pyruvate was the only substrate found to increase growth. The bacterium had a generation time of 4 to 5 days. 3-Chlorobenzoate was dechlorinated stoichiometrically to benzoate, which accumulated in the medium; the rate of dechlorination was ca. 0.1 pmol bacterium/sup -1/ day/sup -1/. The benzoate-oxidizing bacterium was a gram-negative, obligate anaerobe and could only be grown as a syntroph. Benzoate was the only substrate observed to support growth, and, when grown in coculture with M. hungatei, it was fermented to acetate and CH/sub 4/. One butyrate-oxidizing bacterium was a gram-negative, non-sporeforming, obligate anaerobe; the other was a gram-positive, sporeforming, obligate anaerobe. Both could only be grown as syntrophs. The substrates observed to support growth of both bacteria were butyrate, 2-DL-methylbutyrate, valerate, and caproate; isobutyrate supported growth of only the sporeforming bacterium. Fermentation products were acetate and CH/sub 4/ or acetate, propionate, and CH/sub 4/ when grown in coculture with M. hungatei. A mutualism among at least the dechlorinating, benzoate-oxidizing, and methane-forming members was apparently required for utilization of the 3-chlorobenzoate substrate. 21 references, 8 figures, 2 tables.

Shelton, D.R.; Tiedje, J.M.

1984-10-01

115

The effect of statherin and its shortened analogues on anaerobic bacteria isolated from the oral cavity.  

PubMed

The susceptibility (MIC) of 44 strains of anaerobic bacteria isolated from the oral cavity and 3 standard strains to statherin and its C-terminal fragments with sequences QYQQYTF, YQQYTF, QQYTF, QYTF and YTF was determined by means of plate dilution technique in Brucella agar with 5% content of defibrinated sheep's blood, menadione and hemin. The culture was anaerobic. As shown, at concentrations from 12.5 to 100 microg/ml statherin and its C-terminal fragments inhibited the growth of anaerobic bacteria isolated from the oral cavity. Peptostreptococcus strains were the most susceptible to statherin and YTF (MIC < or = 12.5 mg/ml), whereas the most susceptible to the peptides investigated were Fusobacterium necrogenes and Fusobacterium necrophorum strains: QYQQYTF, YQQYTF, QQYTF, QYTF (MIC < or = 12.5 microg/ml). Prevotella oralis, Bacteroides forsythus and Bacteroides ureolyticus strains exhibited the lowest susceptibility (MIC > 100 microg/ml). When analysing the bacteriostatic activity of statherin it should be pointed out that the concentrations of this peptide used in microbiological investigations are within the range of physiological concentrations determined for whole saliva when at rest and stimulated in healthy donors of 19-25 years of age. Since the anaerobes investigated may be involved in the diseases of periodontum, the results presented seem to have also a practical aspect, i.e. a possibility to apply the C-terminal fragments of statherin as a novel therapeutic agent, affecting favourably the oral cavity. PMID:11293657

Kocha?ska, B; Kedzia, A; Kamysz, W; Ma?kiewicz, Z; Kupryszewski, G

2000-01-01

116

34S/32S fractionation in sulfur cycles catalyzed by anaerobic bacteria  

NASA Technical Reports Server (NTRS)

Stable isotopic distributions in the sulfur cycle were studied with pure and mixed cultures of the anaerobic bacteria, Chlorobium vibrioforme and Desulfovibrio vulgaris. D. vulgaris and C. vibrioforme can catalyze three reactions constituting a complete anaerobic sulfur cycle: reduction of sulfate to sulfide (D. vulgaris), oxidation of sulfide to elemental sulfur (C. vibrioforme), and oxidation of sulfur to sulfate (C. vibrioforme). In all experiments, the first and last reactions favored concentration of the light 32S isotope in products (isotopic fractionation factor epsilon = -7.2 and -1.7%, respectively), whereas oxidation of sulfide favored concentration of the heavy 34S isotope in products (epsilon = +1.7%). Experimental results and model calculations suggest that elemental sulfur enriched in 34S versus sulfide may be a biogeochemical marker for the presence of sulfide-oxidizing bacteria in modern and ancient environments.

Fry, B.; Gest, H.; Hayes, J. M.

1988-01-01

117

Formation of dimethylsulfide and methanethiol from methoxylated aromatic compounds and inorganic sulfide by newly isolated anaerobic bacteria  

Microsoft Academic Search

Formation of gas and of methylated sulfur compounds was observed in anaerobic enrichment cultures with methoxylated aromatic compounds as substrates. Via direct dilution of mud samples in defined reduced media supplemented with trimethoxybenzoate or syringate two new strains of anaerobic homoacetogenic bacteria (strain TMBS4 and strain SA2) were obtained in pure culture. Both strains produced dimethylsulfide and methanethiol during growth

Friedhelm Bak; Kai Finster; Franz Rothfuß

1992-01-01

118

FINAL REPORT. REDUCTION AND IMMOBILIZATION OF RADIONUCLIDES AND TOXIC METAL IONS USING COMBINED ZERO VALENT IRON AND ANAEROBIC BACTERIA  

EPA Science Inventory

The use of zero valent iron, permeable reactive barriers (PRBs) for groundwater remediation continues to increase. An exciting variation of this technology involves introducing anaerobic bacteria into these barriers so that both biological and abiotic pollutant removal processes ...

119

Enumeration and Detection of Anaerobic Ferrous Iron Oxidizing, Nitrate-Reducing Bacteria from Diverse European Sediments  

Microsoft Academic Search

Anaerobic, nitrate-dependent microbial oxidation of ferrous iron was recently recognized as a new type of metabolism. In order to study the occurrence of three novel groups of ferrous iron-oxidizing, nitrate-reducing bacteria (represented by strains BrG1, BrG2, and BrG3), 16S rRNA-targeted oligonucleotide probes were developed. In pure-culture experiments, these probes were shown to be suitable for fluorescent in situ hybrid- ization,

KRISTINA L. STRAUB; BERIT E. E. BUCHHOLZ-CLEVEN

1998-01-01

120

Evaluation of the in vitro activity of levornidazole, its metabolites and comparators against clinical anaerobic bacteria.  

PubMed

This study evaluated the in vitro anti-anaerobic activity and spectrum of levornidazole, its metabolites and comparators against 375 clinical isolates of anaerobic bacteria, including Gram-negative bacilli (181 strains), Gram-negative cocci (11 strains), Gram-positive bacilli (139 strains) and Gram-positive cocci (44 strains), covering 34 species. Minimum inhibitory concentrations (MICs) of levornidazole, its five metabolites and three comparators against these anaerobic isolates were determined by the agar dilution method. Minimum bactericidal concentrations (MBCs) of levornidazole and metronidazole were measured against 22 strains of Bacteroides fragilis. Levornidazole showed good activity against B. fragilis, other Bacteroides spp., Clostridium difficile, Clostridium perfringens and Peptostreptococcus magnus, evidenced by MIC90 values of 0.5, 1, 0.25, 2 and 1mg/L, respectively. The activity of levornidazole and the comparators was poor for Veillonella spp. Generally, levornidazole displayed activity similar to or slightly higher than that of metronidazole, ornidazole and dextrornidazole against anaerobic Gram-negative bacilli, Gram-positive bacilli and Gram-positive cocci, especially B. fragilis. Favourable anti-anaerobic activity was also seen with levornidazole metabolites M1 and M4 but not M2, M3 or M5. For the 22 clinical B. fragilis strains, MBC50 and MBC90 values of levornidazole were 2mg/L and 4mg/L, respectively. Both MBC50/MIC50 and MBC90/MIC90 ratios of levornidazole were 4, similar to those of metronidazole. Levornidazole is an important anti-anaerobic option in clinical settings in terms of its potent and broad-spectrum in vitro activity, bactericidal property, and the anti-anaerobic activity of its metabolites M1 and M4. PMID:25301712

Hu, Jiali; Zhang, Jing; Wu, Shi; Zhu, Demei; Huang, Haihui; Chen, Yuancheng; Yang, Yang; Zhang, Yingyuan

2014-12-01

121

Thermophilic, anaerobic bacteria isolated from a deep borehole in granite in Sweden.  

PubMed Central

A borehole drilled to a total depth of 6779 m in granitic rock in Gravberg, Sweden, was sampled and examined for the presence of anaerobic, thermophilic, fermenting bacteria and sulfate-reducing bacteria. Growth in enrichment cultures was obtained only from water samples collected from a specific sampling depth in the borehole (3500 m). The hole was cased down to a depth of 5278 m and open to the formation below that level. All the water below 2000 m in depth standing in the borehole at the time of sampling must have entered at the 5278-m level or below, during a prior pumping operation. A strong salinity stratification certifies that no major amount of vertical mixing had taken place. The depth from which bacteria could be enriched was that of a pronounced local minimum of salinity. Pure cultures of thermophilic, anaerobic, fermenting bacteria were obtained with the following substrates: glucose, starch, xylan, ethanol, and lactate. The morphology and physiology of the glucose- and starch-degrading strains indicate a relationship to Thermoanaerobacter and Thermoanaerobium species. All but one of the newly isolated strains differ however from those by lacking acetate as a fermentation product. The glucose-degrading strain Gluc1 is phylogenetically related to Clostridium thermohydrosulfuricum, with an evolutionary distance based upon rRNA sequence comparisons of 3%. No sulfate-reducing or methanogenic bacteria were found. PMID:11607462

Szewzyk, U; Szewzyk, R; Stenström, T A

1994-01-01

122

Biogeographical distribution of denitrifying anaerobic methane oxidizing bacteria in Chinese wetland ecosystems.  

PubMed

The discovery of denitrifying anaerobic methane oxidation with nitrite as electron acceptor mediated by 'Candidatus?Methylomirabilis oxyfera' connected the biogeochemical carbon and nitrogen cycle in a new way. However, it is important to have a comprehensive understanding about the distribution of M.?oxyfera-like bacteria in the terrestrial realm, especially the wetland ecosystems that are known as the largest natural source of atmospheric methane. Here, our molecular evidence demonstrated that a wide geographical distribution of M.?oxyfera-like bacteria at oxic/anoxic interfaces of various wetlands (n?=?91) over the Chinese territory. Intriguingly, the M.?oxyfera-like bacteria were detected in some extreme environments, indicating that M.?oxyfera-like bacteria occupied a wide range of habitats. Quantitative polymerase chain reaction estimated that the abundance of M.?oxyfera-like bacteria ranged from 2.2?×?10(3) to 2.3?×?10(7) copies?g(-1) dry soil, and up to around 0.62% of the total number of bacteria. Moreover, the M.?oxyfera-like bacteria showed high biodiversity in wetland ecosystems based on the analysis of 462 pmoA and 287 16S rRNA gene sequences. The current study revealed the widespread distribution and biogeography of M.?oxyfera-like bacteria in the terrestrial system. PMID:25223900

Zhu, Guibing; Zhou, Leiliu; Wang, Yu; Wang, Shanyun; Guo, Jianhua; Long, Xi-En; Sun, Xingbin; Jiang, Bo; Hou, Qiaoyun; Jetten, Mike S M; Yin, Chengqing

2015-02-01

123

Bioremediation of acid mine water using facultatively methylotrophic metal-tolerant sulfate-reducing bacteria  

Microsoft Academic Search

A microbial process is proposed for the decontamination of acid uranium mine water high in sulfates and metals. Sulfate reducers are suitable for such a process. Anaerobic reduction of sulfate results in the formation of H2S which leads to an increase in pH and the precipitation of the metals. As cheap an readily available carbon and energy source methanol was

Barbara C. Hard; S. Friedrich; W. Babel

1997-01-01

124

Genome sequence of Phaeobacter daeponensis type strain (DSM 23529T), a facultatively anaerobic bacterium isolated from marine sediment, and emendation of Phaeobacter daeponensis  

PubMed Central

TF-218T is the type strain of the species Phaeobacter daeponensis Yoon et al. 2007, a facultatively anaerobic Phaeobacter species isolated from tidal flats. Here we describe the draft genome sequence and annotation of this bacterium together with previously unreported aspects of its phenotype. We analyzed the genome for genes involved in secondary metabolite production and its anaerobic lifestyle, which have also been described for its closest relative Phaeobacter caeruleus. The 4,642,596 bp long genome of strain TF-218T contains 4,310 protein-coding genes and 78 RNA genes including four rRNA operons and consists of five replicons: one chromosome and four extrachromosomal elements with sizes of 276 kb, 174 kb, 117 kb and 90 kb. Genome analysis showed that TF-218T possesses all of the genes for indigoidine biosynthesis, and on specific media the strain showed a blue pigmentation. We also found genes for dissimilatory nitrate reduction, gene-transfer agents, NRPS/ PKS genes and signaling systems homologous to the LuxR/I system. PMID:24501652

Dogs, Marco; Teshima, Hazuki; Petersen, Jörn; Fiebig, Anne; Chertkov, Olga; Dalingault, Hajnalka; Chen, Amy; Pati, Amrita; Goodwin, Lynne A.; Chain, Patrick; Detter, John C.; Ivanova, Natalia; Lapidus, Alla; Rohde, Manfred; Gronow, Sabine; Kyrpides, Nikos C.; Woyke, Tanja; Simon, Meinhard; Göker, Markus; Klenk, Hans-Peter; Brinkhoff, Thorsten

2013-01-01

125

Diverse Gene Cassettes in Class 1 Integrons of Facultative Oligotrophic Bacteria of River Mahananda, West Bengal, India  

PubMed Central

Background In this study a large random collection (n?=?2188) of facultative oligotrophic bacteria, from 90 water samples gathered in three consecutive years (2007–2009) from three different sampling sites of River Mahananda in Siliguri, West Bengal, India, were investigated for the presence of class 1 integrons and sequences of the amplification products. Methodology/Principal Findings Replica plating method was employed for determining the antibiotic resistance profile of the randomly assorted facultative oligotrophic isolates. Genomic DNA from each isolate was analyzed by PCR for the presence of class 1 integron. Amplicons were cloned and sequenced. Numerical taxonomy and 16S rRNA gene sequence analyses were done to ascertain putative genera of the class 1 integron bearing isolates. Out of 2188 isolates, 1667 (76.19%) were antibiotic-resistant comprising of both single-antibiotic resistance (SAR) and multiple-antibiotic resistant (MAR), and 521 (23.81%) were sensitive to all twelve different antibiotics used in this study. Ninety out of 2188 isolates produced amplicon(s) of varying sizes from 0.15 to 3.45 KB. Chi-square (?2) test revealed that the possession of class 1 integron in sensitive, SAR and MAR is not equally probable at the 1% level of significance. Diverse antibiotic-resistance gene cassettes, aadA1, aadA2, aadA4, aadA5, dfrA1, dfrA5, dfrA7, dfrA12, dfrA16, dfrA17, dfrA28, dfrA30, dfr-IIe, blaIMP-9, aacA4, Ac-6?-Ib, oxa1, oxa10 and arr2 were detected in 64 isolates. The novel cassettes encoding proteins unrelated to any known antibiotic resistance gene function were identified in 26 isolates. Antibiotic-sensitive isolates have a greater propensity to carry gene cassettes unrelated to known antibiotic-resistance genes. The integron-positive isolates under the class Betaproteobacteria comprised of only two genera, Comamonas and Acidovorax of family Comamonadaceae, while isolates under class Gammaproteobacteria fell under the families, Moraxellaceae, Pseudomonadaceae, Aeromonadaceae and Enterobacteriaceae. Conclusions Oligotrophic bacteria are good sources of novel genes as well as potential reservoirs of antibiotic resistance gene casettes. PMID:23951238

Chakraborty, Ranadhir; Kumar, Arvind; Bhowal, Suparna Saha; Mandal, Amit Kumar; Tiwary, Bipransh Kumar; Mukherjee, Shriparna

2013-01-01

126

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

2013-06-01

127

Anaerobic metabolism of nitroaromatic compounds by sulfate-reducing and methanogenic bacteria  

SciTech Connect

Ecological observations suggest that sulfate-reducing and methanogenic bacteria might metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment, but this ability had not been demonstrated until recently. Most studies on the microbial metabolism of nitroaromatic compounds used aerobic microorganisms. In most cases no mineralization of nitroaromatics occurs, and only superficial modifications of the structures are reported. However, under anaerobic sulfate-reducing conditions, the nitroaromatic compounds reportedly undergo a series of reductions with the formation of amino compounds. For example, trinitrotoluene under sulfate-reducing conditions is reduced to triaminotoluene by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of ammonia from triaminotoluene is achieved by reductive deamination catalyzed by the enzyme reductive deaminase, with the production of ammonia and toluene. Some sulfate reducers can metabolize toluene to CO{sub 2}. Similar metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. Many methanogenic bacteria can reduce nitroaromatic compounds to amino compounds. In this paper we review the anaerobic metabolic processes of nitroaromatic compounds under sulfate-reducing And methanogenic conditions.

Boopathy, R. [Argonne National Lab., IL (United States); Kulpa, C.F. [Notre Dame Univ., IN (United States). Dept. of Biological Sciences

1994-06-01

128

Sulfate-reducing bacteria mediate thionation of diphenylarsinic acid under anaerobic conditions.  

PubMed

Diphenylarsinic acid (DPAA) is often found as a toxic intermediate metabolite of diphenylchloroarsine or diphenylcyanoarsine that were produced as chemical warfare agents and were buried in soil after the World Wars. In our previous study Guan et al. (J Hazard Mater 241-242:355-362, 2012), after application of sulfate and carbon sources, anaerobic transformation of DPAA in soil was enhanced with the production of diphenylthioarsinic acid (DPTAA) as a main metabolite. This study aimed to isolate and characterize anaerobic soil microorganisms responsible for the metabolism of DPAA. First, we obtained four microbial consortia capable of transforming DPAA to DPTAA at a high transformation rate of more than 80% after 4 weeks of incubation. Sequencing for the bacterial 16S rRNA gene clone libraries constructed from the consortia revealed that all the positive consortia contained Desulfotomaculum acetoxidans species. In contrast, the absence of dissimilatory sulfite reductase gene (dsrAB) which is unique to sulfate-reducing bacteria was confirmed in the negative consortia showing no DPAA reduction. Finally, strain DEA14 showing transformation of DPAA to DPTAA was isolated from one of the positive consortia. The isolate was assigned to D. acetoxidans based on the partial 16S rDNA sequence analysis. Thionation of DPAA was also carried out in a pure culture of a known sulfate-reducing bacterial strain, Desulfovibrio aerotolerans JCM 12613(T). These facts indicate that sulfate-reducing bacteria are microorganisms responsible for the transformation of DPAA to DPTAA under anaerobic conditions. PMID:25228086

Guan, Ling; Shiiya, Ayaka; Hisatomi, Shihoko; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

2015-02-01

129

Metabolism of the /sup 18/O-methoxy substituent of 3-methoxybenzoic acid and other unlabeled methoxybenzoic acids by anaerobic bacteria. [Eubacterium limosum; Acetobacterium woodil; Syntrophococcus; Clostridium; Desulfotomaculum; Enterobacter  

SciTech Connect

The mechanism of the bioconversion of methoxylated benzoic acids to the hydroxylated derivatives was investigated with a model substrate and cultures of one anaerobic consortium, eight strict anaerobic bacteria, and one facultative anaerobic microorganism. We found that a haloaromatic dehalogenating consortium, a dehalogenating isolate from that consortium, Eubacterium, limosum, and a strain of Acetobacterium woodii metabolized 3-(methoxy-/sup 18/O)methoxybenzoic acid (3-anisic acid) to 3-(hydroxy-/sup 18/O)hydroxybenzoic acid stoichiometrically at rates of 1.5, 3.2, 52.4, and 36.7 nmol/min per mg of protein, respectively. A different strain of Acetobacterium and strains of Syntrophococcus, Clostridium Desulfotomaculum, Enterobacter, and an anaerobic bacterium, strain TH-001, were unable to transform this compound. The O-demethylating ability of E. limosum was induced only with appropriate methoxylated benzoates but not with D-glucose, lactate, isoleucine, or methanol. Cross-acclimation and growth experiments with E. limosum showed a rate of metabolism that was an order of magnitude slower and showed no growth with either 4-methoxysalicylic acid (2-hydroxy-4-methoxybenzoic acid) or 4-anisic acid (4-methoxybenzoic acid) when adapted to 3-anisic acid. However, A. woodii NZva-16 showed slower rates and no growth with 3- or 4-methoxysalicylic acid when adapted to 3-anisic acid in similar experiments.

DeWeerd, J.A.; Saxena, A.; Nagle, D.P. Jr.; Sulflita, J.M.

1988-05-01

130

Broad distribution of diverse anaerobic ammonium-oxidizing bacteria in chinese agricultural soils.  

PubMed

Anaerobic ammonium-oxidizing (anammox) bacteria have been detected in many marine and freshwater ecosystems. However, little is known about the distribution, diversity, and abundance of anammox bacteria in terrestrial ecosystems. In this study, anammox bacteria were found to be present in various agricultural soils collected from 32 different locations in China. Phylogenetic analysis of the 16S rRNA genes showed "Candidatus Brocadia," "Candidatus Kuenenia," "Candidatus Anammoxoglobus," and "Candidatus Jettenia" in the collected soils, with "Candidatus Brocadia" being the dominant genus. Quantitative PCR showed that the abundance of anammox bacteria ranged from 6.38 × 10(4) ± 0.42 × 10(4) to 3.69 × 10(6) ± 0.25 × 10(6) copies per gram of dry weight. Different levels of diversity, composition, and abundance of the anammox bacterial communities were observed, and redundancy analysis indicated that the soil organic content and the distribution of anammox communities were correlated in the soils examined. Furthermore, Pearson correlation analysis showed that the diversity of the anammox bacteria was positively correlated with the soil ammonium content and the organic content, while the anammox bacterial abundance was positively correlated with the soil ammonium content. These results demonstrate the broad distribution of diverse anammox bacteria and its correlation with the soil environmental conditions within an extensive range of Chinese agricultural soils. PMID:23747706

Shen, Li-Dong; Liu, Shuai; Lou, Li-Ping; Liu, Wei-Ping; Xu, Xiang-Yang; Zheng, Ping; Hu, Bao-Lan

2013-10-01

131

Broad Distribution of Diverse Anaerobic Ammonium-Oxidizing Bacteria in Chinese Agricultural Soils  

PubMed Central

Anaerobic ammonium-oxidizing (anammox) bacteria have been detected in many marine and freshwater ecosystems. However, little is known about the distribution, diversity, and abundance of anammox bacteria in terrestrial ecosystems. In this study, anammox bacteria were found to be present in various agricultural soils collected from 32 different locations in China. Phylogenetic analysis of the 16S rRNA genes showed “Candidatus Brocadia,” “Candidatus Kuenenia,” “Candidatus Anammoxoglobus,” and “Candidatus Jettenia” in the collected soils, with “Candidatus Brocadia” being the dominant genus. Quantitative PCR showed that the abundance of anammox bacteria ranged from 6.38 × 104 ± 0.42 × 104 to 3.69 × 106 ± 0.25 × 106 copies per gram of dry weight. Different levels of diversity, composition, and abundance of the anammox bacterial communities were observed, and redundancy analysis indicated that the soil organic content and the distribution of anammox communities were correlated in the soils examined. Furthermore, Pearson correlation analysis showed that the diversity of the anammox bacteria was positively correlated with the soil ammonium content and the organic content, while the anammox bacterial abundance was positively correlated with the soil ammonium content. These results demonstrate the broad distribution of diverse anammox bacteria and its correlation with the soil environmental conditions within an extensive range of Chinese agricultural soils. PMID:23747706

Shen, Li-dong; Liu, Shuai; Lou, Li-ping; Liu, Wei-ping; Xu, Xiang-yang; Zheng, Ping

2013-01-01

132

Antimicrobial susceptibility of anaerobic and capnophilic bacteria isolated from odontogenic abscesses and rapidly progressive periodontitis.  

PubMed

In dentistry antimicrobials are used in the treatment of progressive periodontitis and odontogenic abscesses, therefore the susceptibility to commonly used antibiotics of capnophilic and anaerobic species causing these diseases should be investigated. The activity of penicillin, amoxycillin, cefoxitin, clindamycin, doxycycline, metronidazole and ciprofloxacin was investigated. One hundred and sixty four isolates from subgingival plaque samples of 66 patients with progressive periodontitis and 192 bacterial strains from pus of 74 patients with odontogenic abscesses were included in this study. The majority of species tested were gram-negative anaerobes (Prevotella spp., Porphyromonas spp., Fusobacterium spp.), and were highly susceptible to clindamycin and metronidazole. Nearly 6% of the periodontal isolates and 22% of the bacteria obtained from pus samples produced beta-lactamases. With the exception of the periodontopathogenic species Actinobacillus actinomycetemcomitans and Eikenella corrodens, clindamycin seemed to be a useful antibiotic and could be recommended for empirical antimicrobial treatment. PMID:10389646

Eick, S; Pfister, W; Straube, E

1999-06-01

133

Molecular detection and isolation of facultatively methylotrophic bacteria, including Methylobacterium podarium sp. nov., from the human foot microflora.  

PubMed

This is the first study to demonstrate that diverse methylotrophic bacteria occur in the human foot microflora. Polymerase chain reaction (PCR) amplification of DNA from the soles and toe clefts of feet of five subjects indicated Methylobacterium strains to be present in all cases. Polymerase chain reaction amplification also showed the gene for the alpha-subunit of methanol dehydrogenase (mxaF) to be present in all samples. Two types of mxaF were recovered, one closest to that of Methylobacterium extorquens and the other most similar to that of Hyphomicrobium methylovorum. Numerous methylotrophic strains able to grow on methylamine were isolated with ease from the feet of nine volunteers. These were found by 16S rRNA analysis to be most closely related to Methylobacterium species, Brevibacterium casei, Pseudomonas strain NZ099 and P. migulae. Three strains from two subjects were of a novel species, Methylobacterium podarium sp. nov. This facultatively methylotrophic, obligately aerobic, pink-pigmented, non-motile rod grew with a wide range of multicarbon and one-carbon compounds including citrate, xylose, mono-, di-, and trimethylamine, dimethylsulphide, methanethiol, dimethylsulphoxide, dimethylsulphone and methanol. PMID:15250884

Anesti, Vasiliki; Vohra, Jyotsna; Goonetilleka, Shalini; McDonald, Ian R; Sträubler, Bettina; Stackebrandt, Erko; Kelly, Donovan P; Wood, Ann P

2004-08-01

134

Evaluation of the ATB 32 A system for identification of anaerobic bacteria isolated from clinical specimens.  

PubMed Central

A new miniaturized 4-h method for the identification of anaerobic bacteria, ATB 32 A (API System SA, Montalieu Vercieu, France), was evaluated against conventional methods of identification. The evaluation was done by using 260 recent clinical isolates and 21 reference strains of anaerobic bacteria. All reference strains were correctly identified and did not figure in the detailed analysis. Of the 140 gram-negative bacilli, 90.6% of Bacteroides spp. and 95.5% of Fusobacterium spp. were correctly identified to the species level, with an additional 8.4% of the Bacteroides spp. being identified to the genus level. Clostridia were correctly identified in 85.9% of cases, with an additional 9.9% being identified to the genus level. Peptostreptococci were correctly identified in 91.6% of cases. The 4 strains of Actinomyces spp. were all identified correctly, as were 10 of the 11 strains of Propionibacterium spp. A total of 3.1% of strains were not identified by ATB 32 A, while for 1.9% of strains, completely false identifications were obtained. Estimation of the individual preformed enzyme results may pose problems, although these decrease with familiarity with the system. With certain enzyme profiles, additional testing was necessary to arrive at an identification; however, there was no requirement for gas-liquid chromatography. If certain additions are made to the data base and the difficulties of determination of organisms to the species level among the non-Bacteroides fragilis (sensu stricto) members of the B. fragilis group can be reduced, this system holds promise as a reliable standardized alternative for the identification of anaerobic bacteria in clinical laboratories. PMID:2199516

Looney, W J; Gallusser, A J; Modde, H K

1990-01-01

135

Biogeographical distribution of diverse anaerobic ammonium oxidizing (anammox) bacteria in Cape Fear River Estuary.  

PubMed

Anaerobic ammonium oxidation (anammox) specific PCR method was developed to examine diversity and distribution of anammox bacteria in sediments collected from three different sites at Cape Fear River Estuary, North Carolina, where environmental parameters vary greatly over the year. Abundance and activities of anammox bacteria in these sediments were measured using the quantitative PCR (Q-PCR) method and (15)N isotope tracer incubations. Different anammox bacterial communities composed with Brocadia, Kuenenia, Jettenia or Scalindua were found among sites along the estuarine gradient. Seasonal variations of anammox community structures were observed along the estuary based on terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes. Correlation analysis suggested that salinity variation influenced the diversity and distribution of different anammox bacteria in the estuary. Q-PCR assays of anammox bacteria showed temporal and spatial variations of their abundances, which were highly correlated to salinity variation. (15)N isotope tracer incubations measured different anammox rates and its per cent contribution to total N(2) production among sites. The highest anammox rate was found at the site where Scalindua organisms dominated with the highest anammox bacterial abundance. Thus, we demonstrated a biogeographical distribution of diverse anammox bacteria influenced by salinity, and provide evidence to link anammox abundance and activities in estuarine sediments. PMID:19161435

Dale, Olivia R; Tobias, Craig R; Song, Bongkeun

2009-05-01

136

Vertical distribution of nitrite-dependent anaerobic methane-oxidising bacteria in natural freshwater wetland soils.  

PubMed

Nitrite-dependent anaerobic methane oxidation (n-damo) is a recently discovered process that is catalysed by "Candidatus Methylomirabilis oxyfera". In the present study, the vertical distribution (0-10, 20-30, 50-60 and 90-100 cm) of M. oxyfera-like bacteria was investigated in Xiazhuhu wetland, the largest natural wetland on the southern Yangtze River (China). Phylogenetic analyses showed that group A of M. oxyfera-like bacteria and pmoA genes occurred primarily at depths of 50-60 and 90-100 cm. Quantitative PCR further confirmed the presence of M. oxyfera-like bacteria in soil cores from different depths, with the highest abundance of 5.1?×?10(7) copies g(-1) dry soil at depth of 50-60 cm. Stable isotope experiments demonstrated that the n-damo process occurred primarily at depths of 50-60 and 90-100 cm, with the potential rates ranging from 0.2 to 14.5 nmol CO2?g(-1) dry soil d(-1). It was estimated that the methane flux may increase by approximately 2.7-4.3% in the examined wetland in the absence of n-damo. This study shows that the deep wetland soils (50-60 and 90-100 cm) are the preferred habitats for M. oxyfera-like bacteria. The study also highlights the potential importance of these bacteria in the methane and nitrogen cycles in deep wetland soils. PMID:25242345

Shen, Li-dong; Huang, Qian; He, Zhan-fei; Lian, Xu; Liu, Shuai; He, Yun-feng; Lou, Li-ping; Xu, Xiang-yang; Zheng, Ping; Hu, Bao-lan

2015-01-01

137

[A micromethod for studying the sensitivity of anaerobic bacteria to antibiotics].  

PubMed

The method described here allows to classify anaerobic bacteria isolated from clinical specimens in four categories of sensitivity or resistance to 8 antibiotics. Previous experiments using eight reference strains led to choose the pre-reduced Schaedler broth supplemented with hemin, vitamin K1, and 0.07 p. cent agar. For each group of three concentrations of antibiotics, a check sample could confirm the growth of the bacteria without antibiotic. Very few minor discrepancies were observed when the results of the classification in categories were compared to the MIC in Wilkins-Chalgren solid medium as reference method. These discrepancies were related to the inoculum and specially for fast-growing species as Bacteroides fragilis or Clostridium. The use of an inoculum standardized to 0.5 MF for slow-growing species and 0.5 MF diluted hundred fold for fast-growing one confirmed the good correlation between the two methods in a short delay. PMID:6881623

Nadaud, M

1983-01-01

138

Explicit hypoxia targeting with tumor suppression by creating an “obligate” anaerobic Salmonella Typhimurium strain  

PubMed Central

Using bacteria as therapeutic agents against solid tumors is emerging as an area of great potential in the treatment of cancer. Obligate and facultative anaerobic bacteria have been shown to infiltrate the hypoxic regions of solid tumors, thereby reducing their growth rate or causing regression. However, a major challenge for bacterial therapy of cancer with facultative anaerobes is avoiding damage to normal tissues. Consequently the virulence of bacteria must be adequately attenuated for therapeutic use. By placing an essential gene under a hypoxia conditioned promoter, Salmonella Typhimurium strain SL7207 was engineered to survive only in anaerobic conditions (strain YB1) without otherwise affecting its functions. In breast tumor bearing nude mice, YB1 grew within the tumor, retarding its growth, while being rapidly eliminated from normal tissues. YB1 provides a safe bacterial vector for anti-tumor therapies without compromising the other functions or tumor fitness of the bacterium as attenuation methods normally do. PMID:22666539

Yu, Bin; Yang, Mei; Shi, Lei; Yao, Yandan; Jiang, Qinqin; Li, Xuefei; Tang, Lei-Han; Zheng, Bo-Jian; Yuen, Kwok-Yung; Smith, David K.; Song, Erwei; Huang, Jian-Dong

2012-01-01

139

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

140

Anammox bacteria and the anaerobic oxidation of ammonium in the oxygen minimum zone off northern Chile  

NASA Astrophysics Data System (ADS)

Anammox is the anaerobic oxidation of ammonium by nitrite or nitrate to yield N 2. This process, along with conventional denitrification, contributes to nitrogen loss in oxygen-deficient systems. Anammox is performed by a special group of bacteria belonging to the Planctomycetes phylum. However, information about the distribution, activity, and controlling factors of these anammox bacteria is still limited. Herein, we examine the phylogenetic diversity, vertical distribution, and activity of anammox bacteria in the coastal upwelling region and oxygen minimum zone off northern Chile. The phylogeny of anammox bacteria was studied using primers designed to specifically target 16S rRNA genes from Planctomycetes in samples taken during a cruise in 2004. Anammox bacteria-like sequences affiliated with Candidatus "Scalindua spp." dominated the 16S rRNA gene clone library. However, 62% of the sequences subgrouped separately within this cluster and together with a single sequence retrieved from the suboxic zone of the freshwater Lake Tanganyika. The vertical distribution and activity of anammox bacteria were explored through CARD-FISH (fluorescence in situ hybridization with catalyzed reporter deposition) and 15N labeling incubations, respectively, at two different open-ocean stations during a second cruise in 2005. Anammox bacterial CARD-FISH counts (up to 3000 cells ml -1) and activity (up to 5.75 nmol N 2 L -1 d -1) were only detected at the station subjected directly to the upwelling influence. Anammox cell abundance and activity were highest at 50 m depth, which is the upper part of the OMZ. In this layer, a high abundance of cyanobacteria and a marked nitrogen deficit were also observed. Thus, our results show the presence of a new subcluster within the marine anammox phylogeny and indicate high vertical variability in the abundance and activity of anammox bacteria that could be related to an intensification of carbon and nitrogen cycling in the upper part of the OMZ.

Galán, Alexander; Molina, Verónica; Thamdrup, Bo; Woebken, Dagmar; Lavik, Gaute; Kuypers, Marcel M. M.; Ulloa, Osvaldo

2009-07-01

141

Chlorine isotope fractionation during reductive dechlorination of chlorinated ethenes by anaerobic bacteria.  

PubMed

Chlorine isotope fractionation during reductive dechlorination of trichloroethene (TCE) and tetrachloroethene (PCE) to cis-1,2-dichloroethene (cDCE) by anaerobic bacteria was investigated. The changes in the 37Cl/35Cl ratio observed during the one-step reaction (TCE to cDCE) can be explained by the regioselective elimination of chlorine accompanied by the Rayleigh fractionation. The fractionation factors (alpha) of the TCE dechlorination by three kinds of anaerobic cultures were approximately 0.994-0.995 at 30 degrees C. The enrichment of 37Cl in the organic chlorine during the two-step reaction (PCE to cDCE) can be explained by the random elimination of one chlorine atom in the PCE molecule followed by the regioselective elimination of one chlorine atom in the TCE molecule. The fractionation factors for the first step of the PCE dechlorination with three kinds of anaerobic cultures were estimated to be 0.987-0.991 at 30 degrees C using a mathematical model. Isotope fractionation during the first step would be the primary factor for the chlorine isotope fractionation during the PCE dechorination to cDCE. The developed models can be utilized to evaluate the fractionation factors of regioselective and multistep reactions. PMID:12387413

Numata, Masahiko; Nakamura, Noboru; Koshikawa, Hiromoto; Terashima, Yutaka

2002-10-15

142

Collaborative evaluation of a proposed reference dilution method of susceptibility testing of anaerobic bacteria.  

PubMed

An agar dilution method for susceptibility testing of anaerobic bacteria was evaluated to determine whether results obtained would be consistent enough to recommend it as a reference method. The study was conducted in 10 laboratories where the minimum inhibitory concentrations of six antibiotics (carbenicillin, cefoxitin, chloramphenicol, clindamycin, penicillin G, and tetracycline) were determined against 10 bacterial strains on Wilkins-Chalgren agar prepared by three manufacturers. Minimum inhibitory concentrations falling on the modes varied from 57 to 80% of all determinations and on the mode or within +/-1 log(2) dilution of the mode from 87 to 100% within each laboratory. When data from all laboratories were pooled, minimum inhibitory concentrations from each laboratory agreed with the overall mode 48 to 71% of the time, with an overall agreement at +/-1 log(2) dilution of 96%. This degree of reproducibility allows for recommendation of the procedure as a reference method. Results with three of the test strains were very consistent, and these strains are recommended as control strains: Clostridium perfringens ATCC 13124, Bacteroides fragilis ATCC 25285 and Bacteroides thetaiotaomicron ATCC 29741. The minimum inhibitory concentrations for these strains were on the mode or within +/-1 log(2) dilution of the mode 98, 99, and 99% of the time, respectively. The remaining anaerobic bacteria are recommended as reference strains. PMID:518079

Sutter, V L; Barry, A L; Wilkins, T D; Zabransky, R J

1979-10-01

143

Sialidase (neuraminidase) activity among gram-negative anaerobic and capnophilic bacteria.  

PubMed

A filter paper spot test with 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid as a substrate was used to study the prevalence of sialidase activity among gram-negative anaerobic and capnophilic bacteria. A total of 567 isolates representing four genera of obligate anaerobes and four genera of capnophilic organisms was tested. Sialidase activity was detected in 94% of 66 isolates from the Bacteroides fragilis group, 98% of 66 B. bivius isolates, and all isolates of the following species (number of isolates follows species name): B. capillosus, 4; B. levii, 2; B. denticola, 22; B. loescheii, 23; B. melaninogenicus, 32; B. forsythus, 44; and B. buccalis, 2. However, sialidase activity was detected in only 29% of 7 B. buccae isolates, 79% of 14 B. disiens isolates, and 55% of 11 B. oralis isolates. Sialidase activity was not detected among any of 13 isolates of B. gracilis, 12 isolates of B. ureolyticus, 61 isolates of B. intermedius, or 26 isolates of B. corporis. Porphyromonas (Bacteroides) asaccharolytica (20 isolates) and P. endodontalis (8 isolates) did not demonstrate sialidase activity, while 25 isolates of P. gingivalis were sialidase positive. Sialidase activity was found in 10 (100%) of 10 isolates of Capnocytophaga ochracea of C. sputigena but not in any of 4 C. gingivalis isolates. Other gram-negative anaerobic or capnophilic bacteria, including the following, were negative for sialidase activity: Fusobacterium nucleatum, 39 isolates; Wolinella recta, 19 isolates; Eikenella corrodens, 17 isolates; Haemophilus aphrophilus, 10 isolates; and Actinobacillus actinomycetemcomitans, 10 isolates. These data demonstrate sialidase activity in several species of the genera Bacteroides and Porphyromonas and suggest that this characteristic may be useful for identification. PMID:2108991

Moncla, B J; Braham, P; Hillier, S L

1990-03-01

144

Energetics of end product excretion in anaerobic bacteria and the metabolism of fatty acids by Syntrophomonas wolfei  

SciTech Connect

The study of anaerobic hydrogen-producing syntrophic bacteria is important for several reasons. These bacteria degrade fatty acids which are important intermediates in anaerobic degradation and methanogenesis. The rate and extent of anaerobic degradation of complex polymeric materials often depends on the activity of these organisms. The production of H{sub 2} during anaerobic fatty acid degradation is energetically favorable only when H{sub 2} is maintained at a low level by another bacterium such as a H{sub 2}- using methanogen. Thus, the fatty acid-degrading syntrophic associations serve as excellent models to study the biochemical aspects of mutualism. The fatty acid-degrading syntrophic bacteria are very slow growers since little free energy is released during fatty acid degradation. These bacteria must have very efficient energy conservation systems which are not understood at this time. Further study of these organisms will provide useful information on bioenergetics of living systems. We have chosen to study the metabolism and energetics of the anaerobic, syntrophic, fatty acid degrader, Syntrophomonas wolfei. This organism is the best characterized syntrophic bacterium and serves as an appropriate model organism.

McInerney, M.J.

1986-01-01

145

Living Without Oxygen: Oxygen Tolerance in Bacteria  

NSDL National Science Digital Library

This activity focuses on chemical processes, such as nitrogen fixation and denitrification, which are carried out by bacteria. Often the efficacy of these processes is determined by the amount of oxygen present in the environment in which the bacteria live. Much of the time, these processes are carried out by facultatively anaerobic bacteria in the suboxic region of lakes, oceans, sediments, and leaf litter. Students will discover whether facultatively anaerobic photoautotrophs share the same tolerance for oxygen, how differences in oxygen tolerance can be tested, and of what significance the tolerance for oxygen is in the nitrogen cycle. They will practice aseptic technique, monitor the growth of bacterial cultures, display their results graphically, and propose environmental problems associated with the oxygen tolerance of nitrogen fixers and denitifiers.

Sharon Harris

146

Anaerobic bacteria grow within Candida albicans biofilms and induce biofilm formation in suspension cultures.  

PubMed

The human microbiome contains diverse microorganisms, which share and compete for the same environmental niches. A major microbial growth form in the human body is the biofilm state, where tightly packed bacterial, archaeal, and fungal cells must cooperate and/or compete for resources in order to survive. We examined mixed biofilms composed of the major fungal species of the gut microbiome, Candida albicans, and each of five prevalent bacterial gastrointestinal inhabitants: Bacteroides fragilis, Clostridium perfringens, Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. We observed that biofilms formed by C. albicans provide a hypoxic microenvironment that supports the growth of two anaerobic bacteria, even when cultured in ambient oxic conditions that are normally toxic to the bacteria. We also found that coculture with bacteria in biofilms induces massive gene expression changes in C. albicans, including upregulation of WOR1, which encodes a transcription regulator that controls a phenotypic switch in C. albicans, from the "white" cell type to the "opaque" cell type. Finally, we observed that in suspension cultures, C. perfringens induces aggregation of C. albicans into "mini-biofilms," which allow C. perfringens cells to survive in a normally toxic environment. This work indicates that bacteria and C. albicans interactions modulate the local chemistry of their environment in multiple ways to create niches favorable to their growth and survival. PMID:25308076

Fox, Emily P; Cowley, Elise S; Nobile, Clarissa J; Hartooni, Nairi; Newman, Dianne K; Johnson, Alexander D

2014-10-20

147

Investigation of the relation between anaerobic bacteria genus clostridium and late-onset autism etiology in children.  

PubMed

The aim of this study was to investigate the relation between the etiology of late-onset childhood autism and anaerobic bacteria. Thirty children diagnosed with autistic disorder and control group have been included in the study. 3-(3-hydroxy phenyl)-3-hydroxypropionic acid (HPHPA) excretion rates which is a metabolic product of the genus Clostridium, were measured via mass spectrometry-gas chromatography (MS-GC) method from urine samples. When the assayed average HPHPA values compared with each group, a statistically significant difference was found (p < 0.05). Data obtained from this study support the existence of a significant correlation between autism etiology and anaerobic bacteria. PMID:24063620

Ke?li, Recep; Gökçen, Cem; Bulu?, Ufuk; Terzi, Yüksel

2014-01-01

148

Molecular Detection of Anaerobic Ammonium-Oxidizing (Anammox) Bacteria in High-Temperature Petroleum Reservoirs  

PubMed Central

Anaerobic ammonium-oxidizing (anammox) process plays an important role in the nitrogen cycle of the worldwide anoxic and mesophilic habitats. Recently, the existence and activity of anammox bacteria have been detected in some thermophilic environments, but their existence in the geothermal subterranean oil reservoirs is still not reported. This study investigated the abundance, distribution and functional diversity of anammox bacteria in nine out of 17 high-temperature oil reservoirs by molecular ecology analysis. High concentration (5.31–39.2 mg l?1) of ammonium was detected in the production water from these oilfields with temperatures between 55°C and 75°C. Both 16S rRNA and hzo molecular biomarkers indicated the occurrence of anammox bacteria in nine out of 17 samples. Most of 16S rRNA gene phylotypes are closely related to the known anammox bacterial genera Candidatus Brocadia, Candidatus Kuenenia, Candidatus Scalindua, and Candidatus Jettenia, while hzo gene phylotypes are closely related to the genera Candidatus Anammoxoglobus, Candidatus Kuenenia, Candidatus Scalindua, and Candidatus Jettenia. The total bacterial and anammox bacterial densities were 6.4?±?0.5?×?103 to 2.0?±?0.18?×?106 cells ml?1 and 6.6?±?0.51?×?102 to 4.9?±?0.36?×?104 cell ml?1, respectively. The cluster I of 16S rRNA gene sequences showed distant identity (<92%) to the known Candidatus Scalindua species, inferring this cluster of anammox bacteria to be a new species, and a tentative name Candidatus “Scalindua sinooilfield” was proposed. The results extended the existence of anammox bacteria to the high-temperature oil reservoirs. PMID:20740282

Li, Hui; Chen, Shuo; Mu, Bo-Zhong

2010-01-01

149

Interactions of Anaerobic Bacteria with Dental Stem Cells: An In Vitro Study  

PubMed Central

Background In patients with periodontitis, it is highly likely that local (progenitor) cells encounter pathogenic bacteria. The purpose of this in vitro study was to elucidate how human dental follicle stem cells (hDFSC) react towards a direct challenge with anaerobic periodontal pathogens under their natural oxygen-free atmosphere. HDFSC were compared to human bone marrow mesenchymal stem cells (hBMSC) and differentiated primary human gingival fibroblasts (hGiF), as well as permanent gingival carcinoma cells (Ca9-22). Methodology/Principal Findings The different cell types were investigated in a co-culture system with Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum). The viability of the cells and pathogens under anaerobic conditions, as well as interactions in terms of adherence and internalization, were examined. Additionally, the release of pro-inflammatory interleukin-8 (IL-8) and anti-inflammatory interleukin-10 (IL-10) was quantified via enzyme-linked immunosorbent assay. The bacteria adhered less efficiently to hDFSC compared to Ca9-22 (P. gingivalis: 0.18% adherence to hDFSC; 3.1% adherence to Ca9-22). Similar results were observed for host cell internalization (F. nucleatum: 0.002% internalization into hDFSC; 0.09% internalization into Ca9-22). Statistically significantly less IL-8 was secreted from hDFSC after stimulation with F. nucleatum and P. gingivalis in comparison with hGiF (F. nucleatum: 2080.0 pg/ml – hGiF; 19.7 pg/ml – hDFSC). The IL-10 response of the differentiated cells was found to be low in relation to their pro-inflammatory IL-8 response. Conclusions/Significance The results indicate that dental stem cells are less prone to interactions with pathogenic bacteria than differentiated cells in an anaerobic environment. Moreover, during bacterial challenge, the stem cell immune response seems to be more towards an anti-inflammatory reaction. For a potential future therapeutic use of hDFSC, these findings support the idea of a save application. PMID:25369260

Biedermann, Anne; Kriebel, Katja; Kreikemeyer, Bernd; Lang, Hermann

2014-01-01

150

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

151

Characterization and Description of Anaeromyxobacter dehalogenans gen. nov., sp. nov., an Aryl-Halorespiring Facultative Anaerobic Myxobacterium  

PubMed Central

Five strains were isolated which form a physiologically and phylogenetically coherent group of chlororespiring microorganisms and represent the first taxon in the Myxobacteria capable of anaerobic growth. The strains were enriched and isolated from various soils and sediments based on their ability to grow using acetate as an electron donor and 2-chlorophenol (2-CPh) as an electron acceptor. They are slender gram-negative rods with a bright red pigmentation that exhibit gliding motility and form spore-like structures. These unique chlororespiring myxobacteria also grow with 2,6-dichlorophenol, 2,5-dichlorophenol, 2-bromophenol, nitrate, fumarate, and oxygen as terminal electron acceptors, with optimal growth occurring at low concentrations (<1 mM) of electron acceptor. 2-CPh is reduced by all strains as an electron acceptor in preference to nitrate, which is reduced to ammonium. Acetate, H2, succinate, pyruvate, formate, and lactate were used as electron donors. None of the strains grew by fermentation. The 16S ribosomal DNA (rDNA) sequences of the five strains form a coherent cluster deeply branching within the family Myxococcaceae within the class Myxobacteria and are mostly closely associated with the Myxococcus subgroup. With the exception of anaerobic growth and lack of a characteristic fruiting body, these strains closely resemble previously characterized myxobacteria and therefore should be considered part of the Myxococcus subgroup. The anaerobic growth and 9.0% difference in 16S rDNA sequence from those of other myxobacterial genera are sufficient to place these strains in a new genus and species designated Anaeromyxobacter dehalogenans. The type strain is 2CP-1 (ATCC BAA-258). PMID:11823233

Sanford, Robert A.; Cole, James R.; Tiedje, James M.

2002-01-01

152

Co-occurrence of nitrite-dependent anaerobic methane oxidizing and anaerobic ammonia oxidizing bacteria in two Qinghai-Tibetan saline lakes  

NASA Astrophysics Data System (ADS)

Nitrite-dependent anaerobic methane-oxidizing (n-damo) bacteria and anaerobic ammonia oxidizing (anammox) bacteria are two groups of microorganisms involved in global carbon and nitrogen cycling. In order to test whether the n-damo and anammox bacteria co-occur in natural saline environments, the DNA and cDNA samples obtained from the surficial sediments of two saline lakes (with salinity of 32 and 84 g/L, respectively) on the Tibetan Plateau were PCR-amplified with the use of anammox- and n-damo-specific primer sets, followed by clone library construction and phylogenetic analysis. DNA and cDNA-based clones affiliated with n-damo and anammox bacteria were successfully retrieved from the two samples, indicating that these two groups of bacteria can co-occur in natural saline environments with salinity as high as 84 g/L. Our finding has great implications for our understanding of the global carbon and nitrogen cycle in nature.

Yang, Jian; Jiang, Hongchen; Wu, Geng; Hou, Weiguo; Sun, Yongjuan; Lai, Zhongping; Dong, Hailiang

2012-12-01

153

In vitro activities of daptomycin (LY146032) and paldimycin (U-70,138F) against anaerobic gram-positive bacteria.  

PubMed

The in vitro activities of daptomycin (LY146032), paldimycin (U-70,138F), vancomycin, and penicillin G against 344 clinical isolates of anaerobic gram-positive bacteria were determined by an agar dilution method in calcium-supplemented (50 micrograms/ml) Wilkins-Chalgren medium, using an inoculum of 10(5) CFU. Daptomycin demonstrated excellent activity against a broad range of anaerobic gram-positive cocci and bacilli, including Peptostreptococcus, Eubacterium, Bifidobacterium, Actinomyces, Propionibacterium, and Lactobacillus species and Clostridium difficile. Highly resistant strains (MIC, greater than or equal to 64 micrograms/ml) were encountered sporadically from different genera, but these accounted for only 3% of all isolates tested. Vancomycin showed similar activity but was less active against Lactobacillus species and Peptostreptococcus prevotii. Paldimycin was inactive against most genera of anaerobic gram-positive bacteria. Overall, penicillin G remained the most broadly active agent against these isolates. PMID:2840019

Chow, A W; Cheng, N

1988-05-01

154

Prefeeding-dependent anaerobic metabolization of xenobiotics by intestinal bacteria —methods for Acarbose metabolites in an artificial colon  

Microsoft Academic Search

Summary The biotransformation of Acarbose (Bay g 5421) by an artificial in vitro system with viable intestinal microorganisms was investigated. The bacteria were obtained from the colon of man or from the caecum and colon of rats and were incubated anaerobically with14C-Acarbose in a nutrient solution. The metabolites were separated and purified by Chromatographic methods and identified by nuclear magnetic

M. Pfeffer; G. Siebert

1986-01-01

155

An in Vitro Experimental Study on the Antimicrobial Activity of Silicone Oil against Anaerobic Bacteria.  

PubMed

Abstract Purpose: To investigate the in vitro antimicrobial activity of silicone oil against anaerobic agents, specifically Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium. Method: A 0.5 McFarland turbidity of Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium was prepared, and 0.1?mL was inoculated into 0.9?mL of silicone oil. Control inoculations were performed in anaerobic blood agar and fluid thioglycollate medium without silicone oil. Results: Propionibacterium acnes retained their viability on the 3rd day in the presence of silicone oil. In total, 9.7?×?10(6) colonies were enumerated from 1?mL of silicone oil. After a prolonged incubation of 7 days, the number of colonies observed was 9.2?×?10(6). The other bacteria disappeared after the 3rd day of incubation in silicone oil. Conclusions: Propionibacterium acnes, which is the most common chronic postoperative endophthalmitis agent, is thought to be resistant to silicone oil. PMID:25356916

Arici, Ceyhun; Aras, Cengiz; Tokman, Hrisi Bahar; Torun, Muzeyyen Mamal

2014-10-30

156

Evaluating Primers for Profiling Anaerobic Ammonia Oxidizing Bacteria within Freshwater Environments  

PubMed Central

Anaerobic ammonia oxidizing (anammox) bacteria play an important role in transforming ammonium to nitrogen gas and contribute to fixed nitrogen losses in freshwater environments. Understanding the diversity and abundance of anammox bacteria requires reliable molecular tools, and these are not yet well established for these important Planctomycetes. To help validate PCR primers for the detection of anammox bacteria within freshwater ecosystems, we analyzed representative positive controls and selected samples from Grand River and groundwater sites, both from Ontario, Canada. The objectives of this study were to identify a suitable anammox denaturing gradient gel electrophoresis (DGGE) fingerprint method by using GC-clamp modifications to existing primers, and to verify the specificity of anammox-specific primers used for DGGE, cloning and qPCR methods. Six primer combinations were tested from four published primer sets (i.e. A438f/A684r, Amx368f/Amx820r, An7f/An1388r, and Pla46/1392r) for both direct and nested PCR amplifications. All PCR products were run subsequently on DGGE gels to compare the resulting patterns. Two anammox-specific primer combinations were also used to generate clone libraries and quantify anammox bacterial 16S rRNA genes with qPCR. The primer set A438f/A684r was highly specific to anammox bacteria, provided reliable DGGE fingerprints and generated a high proportion of anammox-related clones. A second primer set (Amx368f/Amx820r) was anammox specific, based on clone library analysis, but PCR products from different candidate species of anammox bacteria resolved poorly using DGGE analysis. Both DGGE and cloning results revealed that Ca. Brocadia and an uncharacterized anammox bacterial cluster represented the majority of anammox bacteria found in Grand River sediment and groundwater samples, respectively. Together, our results demonstrate that although Amx368f/Amx820r was useful for anammox-specific qPCR and clone library analysis, A438f/A684r was the most suitable primer set for multiple molecular assessments of anammox bacteria in freshwater environments. PMID:23505422

Sonthiphand, Puntipar; Neufeld, Josh D.

2013-01-01

157

Novel [NiFe]- and [FeFe]-Hydrogenase Gene Transcripts Indicative of Active Facultative Aerobes and Obligate Anaerobes in Earthworm Gut Contents?†  

PubMed Central

The concomitant occurrence of molecular hydrogen (H2) and organic acids along the alimentary canal of the earthworm is indicative of ongoing fermentation during gut passage. Fermentative H2 production is catalyzed by [FeFe]-hydrogenases and group 4 [NiFe]-hydrogenases in obligate anaerobes (e.g., Clostridiales) and facultative aerobes (e.g., Enterobacteriaceae), respectively, functional groups that might respond differently to contrasting redox conditions. Thus, the objectives of this study were to assess the redox potentials of the alimentary canal of Lumbricus terrestris and analyze the hydrogenase transcript diversities of H2 producers in glucose-supplemented gut content microcosms. Although redox potentials in the core of the alimentary canal were variable on an individual worm basis, average redox potentials were similar. The lowest redox potentials occurred in the foregut and midgut regions, averaging 40 and 110 mV, respectively. Correlation plots between hydrogenase amino acid sequences and 16S rRNA gene sequences indicated that closely related hydrogenases belonged to closely related taxa, whereas distantly related hydrogenases did not necessarily belong to distantly related taxa. Of 178 [FeFe]-hydrogenase gene transcripts, 177 clustered in 12 Clostridiales-affiliated operational taxonomic units, the majority of which were indicative of heretofore unknown hydrogenases. Of 86 group 4 [NiFe]-hydrogenase gene transcripts, 79% and 21% were affiliated with organisms in the Enterobacteriaceae and Aeromonadaceae, respectively. The collective results (i) suggest that fermenters must cope with variable and moderately oxidative redox conditions along the alimentary canal, (ii) demonstrate that heretofore undetected hydrogenases are present in the earthworm gut, and (iii) corroborate previous findings implicating Clostridiaceae and Enterobacteriaceae as active fermentative taxa in earthworm gut content. PMID:21784904

Schmidt, Oliver; Wüst, Pia K.; Hellmuth, Susanne; Borst, Katharina; Horn, Marcus A.; Drake, Harold L.

2011-01-01

158

Telmatobacter bradus gen. nov., sp. nov., a cellulolytic facultative anaerobe from subdivision 1 of the Acidobacteria, and emended description of Acidobacterium capsulatum Kishimoto et al. 1991.  

PubMed

A gram-negative, facultatively anaerobic, chemo-organotrophic, non-pigmented, slow-growing bacterium was isolated from acidic Sphagnum peat and designated strain TPB6017(T). Cells of this strain were long rods that multiplied by normal cell division and were motile by means of a single flagellum. Cells grew under reduced oxygen tension and under anoxic conditions and were able to ferment sugars and several polysaccharides, including amorphous and crystalline cellulose. Strain TPB6017(T) was a psychrotolerant acidophile capable of growth between pH 3.0 and 7.5 (optimum 4.5-5.0) and at 4-35 °C (optimum 20-28 °C). It was extremely sensitive to salt stress; growth was inhibited at NaCl concentrations above 0.1?% (w/v). The major fatty acids were iso-C(15?:?0) and iso-C(17?:?1)?9c; the polar lipids were phosphatidylethanolamine and a number of phospholipids and aminophospholipids with an unknown structure. The quinone was MK-8. The DNA G+C content was 57.6 mol%. Comparative 16S rRNA gene sequence analysis revealed that strain TPB6017(T) was a member of subdivision 1 of the phylum Acidobacteria and belonged to a phylogenetic lineage defined by the acidophilic aerobic chemo-organotroph Acidobacterium capsulatum (92.3?% sequence similarity). However, cell morphology, type of flagellation, the absence of pigment, differences in fatty acid and polar lipid composition, possession of a cellulolytic capability, inability to grow under fully oxic conditions and good growth in anoxic conditions distinguished strain TPB6017(T) from A. capsulatum. Therefore, it is proposed that strain TPB6017(T) represents a novel acidobacterium species in a new genus, Telmatobacter bradus gen. nov., sp. nov.; strain TPB6017(T) (?=?DSM 23630(T)?=?VKM B-2570(T)) is the type strain. PMID:21460138

Pankratov, Timofey A; Kirsanova, Lilia A; Kaparullina, Elena N; Kevbrin, Vadim V; Dedysh, Svetlana N

2012-02-01

159

Decarboxylating and Nondecarboxylating Glutaryl-Coenzyme A Dehydrogenases in the Aromatic Metabolism of Obligately Anaerobic Bacteria?  

PubMed Central

In anaerobic bacteria using aromatic growth substrates, glutaryl-coenzyme A (CoA) dehydrogenases (GDHs) are involved in the catabolism of the central intermediate benzoyl-CoA to three acetyl-CoAs and CO2. In this work, we studied GDHs from the strictly anaerobic, aromatic compound-degrading organisms Geobacter metallireducens (GDHGeo) (Fe[III] reducing) and Desulfococcus multivorans (GDHDes) (sulfate reducing). GDHGeo was purified from cells grown on benzoate and after the heterologous expression of the benzoate-induced bamM gene. The gene coding for GDHDes was identified after screening of a cosmid gene library. Reverse transcription-PCR revealed that its expression was induced by benzoate; the product was heterologously expressed and isolated. Both wild-type and recombinant GDHGeo catalyzed the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA at similar rates. In contrast, recombinant GDHDes catalyzed only the dehydrogenation to glutaconyl-CoA. The latter compound was decarboxylated subsequently to crotonyl-CoA by the addition of membrane extracts from cells grown on benzoate in the presence of 20 mM NaCl. All GDH enzymes were purified as homotetramers of a 43- to 44-kDa subunit and contained 0.6 to 0.7 flavin adenine dinucleotides (FADs)/monomer. The kinetic properties for glutaryl-CoA conversion were as follows: for GDHGeo, the Km was 30 ± 2 ?M and the Vmax was 3.2 ± 0.2 ?mol min?1 mg?1, and for GDHDes, the Km was 52 ± 5 ?M and the Vmax was 11 ± 1 ?mol min?1 mg?1. GDHDes but not GDHGeo was inhibited by glutaconyl-CoA. Highly conserved amino acid residues that were proposed to be specifically involved in the decarboxylation of the intermediate glutaconyl-CoA were identified in GDHGeo but are missing in GDHDes. The differential use of energy-yielding/energy-demanding enzymatic processes in anaerobic bacteria that degrade aromatic compounds is discussed in view of phylogenetic relationships and constraints of overall energy metabolism. PMID:19395484

Wischgoll, Simon; Taubert, Martin; Peters, Franziska; Jehmlich, Nico; von Bergen, Martin; Boll, Matthias

2009-01-01

160

Decarboxylating and nondecarboxylating glutaryl-coenzyme A dehydrogenases in the aromatic metabolism of obligately anaerobic bacteria.  

PubMed

In anaerobic bacteria using aromatic growth substrates, glutaryl-coenzyme A (CoA) dehydrogenases (GDHs) are involved in the catabolism of the central intermediate benzoyl-CoA to three acetyl-CoAs and CO(2). In this work, we studied GDHs from the strictly anaerobic, aromatic compound-degrading organisms Geobacter metallireducens (GDH(Geo)) (Fe[III] reducing) and Desulfococcus multivorans (GDH(Des)) (sulfate reducing). GDH(Geo) was purified from cells grown on benzoate and after the heterologous expression of the benzoate-induced bamM gene. The gene coding for GDH(Des) was identified after screening of a cosmid gene library. Reverse transcription-PCR revealed that its expression was induced by benzoate; the product was heterologously expressed and isolated. Both wild-type and recombinant GDH(Geo) catalyzed the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA at similar rates. In contrast, recombinant GDH(Des) catalyzed only the dehydrogenation to glutaconyl-CoA. The latter compound was decarboxylated subsequently to crotonyl-CoA by the addition of membrane extracts from cells grown on benzoate in the presence of 20 mM NaCl. All GDH enzymes were purified as homotetramers of a 43- to 44-kDa subunit and contained 0.6 to 0.7 flavin adenine dinucleotides (FADs)/monomer. The kinetic properties for glutaryl-CoA conversion were as follows: for GDH(Geo), the K(m) was 30 +/- 2 microM and the V(max) was 3.2 +/- 0.2 micromol min(-1) mg(-1), and for GDH(Des), the K(m) was 52 +/- 5 microM and the V(max) was 11 +/- 1 micromol min(-1) mg(-1). GDH(Des) but not GDH(Geo) was inhibited by glutaconyl-CoA. Highly conserved amino acid residues that were proposed to be specifically involved in the decarboxylation of the intermediate glutaconyl-CoA were identified in GDH(Geo) but are missing in GDH(Des). The differential use of energy-yielding/energy-demanding enzymatic processes in anaerobic bacteria that degrade aromatic compounds is discussed in view of phylogenetic relationships and constraints of overall energy metabolism. PMID:19395484

Wischgoll, Simon; Taubert, Martin; Peters, Franziska; Jehmlich, Nico; von Bergen, Martin; Boll, Matthias

2009-07-01

161

Detection of bacteria from a cecal anaerobic competitive exclusion culture with an immunoassay electrochemiluminescence sensor  

NASA Astrophysics Data System (ADS)

A competitive exclusion (CE) culture of chicken cecal anaerobes has been developed and used in this laboratory for control of Salmonella typhimurium in chickens. The CE culture consists of 29 different species of micro-organisms, and is known as CF3. Detection of one of the CF3 bacteria, Eubacteria, and S. typhimurium were demonstrated using a commercial immunomagnetic (IM) electrochemiluminescence (ECL) sensor, the ORIGENR Analyzer. Analysis was achieved using a sandwich immunoassay. Bacteria were captured on antibody- conjugated 280 micron sized magnetic beads followed by binding of reporter antibodies labelled with ruthenium (II) tris(dipyridyl) chelate [Ru(bpy)32+]. The magnetic beads were then trapped on an electrode in the reaction cell of the ORIGENR Analyzer by a magnet, and the ECL was evoked from Ru(bpy)32+ on the tagged reporter antibodies by an electrical potential at the electrode. Preliminary IM-ECL assays with Eubacteria yielded a detection limit of 105 cfu/mL. Preliminary IM-ECL assays with S. typhimurium yielded a similar detection limit of 105 cfu/mL.

Beier, Ross C.; Young, Colin R.; Stanker, Larry H.

1999-01-01

162

Distribution and environmental significance of nitrite-dependent anaerobic methane-oxidising bacteria in natural ecosystems.  

PubMed

Nitrite-dependent anaerobic methane oxidation (N-DAMO) is a recently discovered process that is performed by "Candidatus Methylomirabilis oxyfera" (M. oxyfera). This process constitutes a unique association between the two major global elements essential to life, carbon and nitrogen, and may act as an important and overlooked sink of the greenhouse gas methane. In recent years, more and more studies have reported the distribution of M. oxyfera-like bacteria and the occurrence of N-DAMO process in different natural ecosystems, including freshwater lakes, rivers, wetlands and marine ecosystems. Previous studies have estimated that a total of 2%-6% of current worldwide methane flux in wetlands could be consumed via the N-DAMO process. These findings indicate that N-DAMO is indeed a previously overlooked methane sink in natural ecosystems. Given the worldwide increase in anthropogenic nitrogen pollution, the N-DAMO process as a methane sink in reducing global warming could become more important in the future. The present mini-review summarises the current knowledge of the ecological distribution of M. oxyfera-like bacteria and the potential importance of the N-DAMO process in reducing methane emissions in various natural ecosystems. The potential influence of environmental factors on the N-DAMO process is also discussed. PMID:25398284

Shen, Li-dong; Wu, Hong-sheng; Gao, Zhi-qiu

2015-01-01

163

Cultivation of Planktonic Anaerobic Ammonium Oxidation (Anammox) Bacteria Using Membrane Bioreactor  

PubMed Central

Enrichment cultures of anaerobic ammonium oxidation (anammox) bacteria as planktonic cell suspensions are essential for studying their ecophysiology and biochemistry, while their cultivation is still laborious. The present study aimed to cultivate two phylogenetically distinct anammox bacteria, “Candidatus Brocadia sinica” and “Ca. Scalindua sp.” in the form of planktonic cells using membrane bioreactors (MBRs). The MBRs were continuously operated for more than 250 d with nitrogen loading rates of 0.48–1.02 and 0.004–0.09 kgN m?3 d?1 for “Ca. Brocadia sinica” and “Ca. Scalindua sp.”, respectively. Planktonic anammox bacterial cells were successfully enriched (>90%) in the MBRs, which was confirmed by fluorescence in-situ hybridization and 16S rRNA gene sequencing analysis. The decay rate and half-saturation constant for NO2? of “Ca. Brocadia sinica” were determined to be 0.0029–0.0081 d?1 and 0.47 mgN L?1, respectively, using enriched planktonic cells. The present study demonstrated that MBR enables the culture of planktonic anammox bacterial cells, which are suitable for studying their ecophysiology and biochemistry. PMID:24200833

Oshiki, Mamoru; Awata, Takanori; Kindaichi, Tomonori; Satoh, Hisashi; Okabe, Satoshi

2013-01-01

164

Anaerobic ammonium-oxidising bacteria: A biological source of the bacteriohopanetetrol stereoisomer in marine sediments  

NASA Astrophysics Data System (ADS)

Bacterially-derived bacteriohopanepolyols (BHPs) are abundant, well preserved lipids in modern and paleo-environments. Bacteriohopanetetrol (BHT) is a ubiquitously produced BHP while its less common stereoisomer (BHT isomer) has previously been associated with anoxic environments; however, its biological source remained unknown. We investigated the occurrence of BHPs in Golfo Dulce, an anoxic marine fjord-like enclosure located in Costa Rica. The distribution of BHT isomer in four sediment cores and a surface sediment transect closely followed the distribution of ladderane fatty acids, unique biomarkers for bacteria performing anaerobic ammonium oxidation (anammox). This suggests that BHT isomer and ladderane lipids likely shared the same biological source in Golfo Dulce. This was supported by examining the BHP lipid compositions of two enrichment cultures of a marine anammox species (‘Candidatus Scalindua profunda’), which were found to contain both BHT and BHT isomer. Remarkably, the BHT isomer was present in higher relative abundance than BHT. However, a non-marine anammox enrichment contained only BHT, which explains the infrequence of BHT isomer observations in terrestrial settings, and indicates that marine anammox bacteria are likely responsible for at least part of the environmentally-observed marine BHT isomer occurrences. Given the substantially greater residence time of BHPs in sediments, compared to ladderanes, BHT isomer is a potential biomarker for past anammox activity.

Rush, Darci; Sinninghe Damsté, Jaap S.; Poulton, Simon W.; Thamdrup, Bo; Garside, A. Leigh; Acuña González, Jenaro; Schouten, Stefan; Jetten, Mike S. M.; Talbot, Helen M.

2014-09-01

165

Electricity generation by anaerobic bacteria and anoxic sediments from hypersaline soda lakes  

USGS Publications Warehouse

Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate as the electron acceptor. However, these cultures grew equally well without added arsenate using the MFC anode as their electron acceptor, and in the process oxidized lactate more efficiently. The decrease in electricity generation by consumption of added alternative electron acceptors (i.e. arsenate) which competed with the anode for available electrons proved to be a useful indicator of microbial activity and hence life in the fuel cells. Shaken sediment slurries from these two lakes also generated electricity, with or without added lactate. Hydrogen added to sediment slurries was consumed but did not stimulate electricity production. Finally, electricity was generated in statically incubated "intact" sediment cores from these lakes. More power was produced in sediment from Mono Lake than from Searles Lake, however microbial fuel cells could detect low levels of metabolism operating under moderate and extreme conditions of salt stress. ?? 2008 US Government.

Miller, L.G.; Oremland, R.S.

2008-01-01

166

Biology, ecology, and biotechnological applications of anaerobic bacteria adapted to environmental stresses in temperature, pH, salinity, or substrates.  

PubMed Central

Anaerobic bacteria include diverse species that can grow at environmental extremes of temperature, pH, salinity, substrate toxicity, or available free energy. The first evolved archaebacterial and eubacterial species appear to have been anaerobes adapted to high temperatures. Thermoanaerobes and their stable enzymes have served as model systems for basic and applied studies of microbial cellulose and starch degradation, methanogenesis, ethanologenesis, acetogenesis, autotrophic CO2 fixation, saccharidases, hydrogenases, and alcohol dehydrogenases. Anaerobes, unlike aerobes, appear to have evolved more energy-conserving mechanisms for physiological adaptation to environmental stresses such as novel enzyme activities and stabilities and novel membrane lipid compositions and functions. Anaerobic syntrophs do not have similar aerobic bacterial counterparts. The metabolic end products of syntrophs are potent thermodynamic inhibitors of energy conservation mechanisms, and they require coordinated consumption by a second partner organism for species growth. Anaerobes adapted to environmental stresses and their enzymes have biotechnological applications in organic waste treatment systems and chemical and fuel production systems based on biomass-derived substrates or syngas. These kinds of anaerobes have only recently been examined by biologists, and considerably more study is required before they are fully appreciated by science and technology. Images PMID:8336675

Lowe, S E; Jain, M K; Zeikus, J G

1993-01-01

167

Nitrate-Dependent Ferrous Iron Oxidation by Anaerobic Ammonium Oxidation (Anammox) Bacteria  

PubMed Central

We examined nitrate-dependent Fe2+ oxidation mediated by anaerobic ammonium oxidation (anammox) bacteria. Enrichment cultures of “Candidatus Brocadia sinica” anaerobically oxidized Fe2+ and reduced NO3? to nitrogen gas at rates of 3.7 ± 0.2 and 1.3 ± 0.1 (mean ± standard deviation [SD]) nmol mg protein?1 min?1, respectively (37°C and pH 7.3). This nitrate reduction rate is an order of magnitude lower than the anammox activity of “Ca. Brocadia sinica” (10 to 75 nmol NH4+ mg protein?1 min?1). A 15N tracer experiment demonstrated that coupling of nitrate-dependent Fe2+ oxidation and the anammox reaction was responsible for producing nitrogen gas from NO3? by “Ca. Brocadia sinica.” The activities of nitrate-dependent Fe2+ oxidation were dependent on temperature and pH, and the highest activities were seen at temperatures of 30 to 45°C and pHs ranging from 5.9 to 9.8. The mean half-saturation constant for NO3? ± SD of “Ca. Brocadia sinica” was determined to be 51 ± 21 ?M. Nitrate-dependent Fe2+ oxidation was further demonstrated by another anammox bacterium, “Candidatus Scalindua sp.,” whose rates of Fe2+ oxidation and NO3? reduction were 4.7 ± 0.59 and 1.45 ± 0.05 nmol mg protein?1 min?1, respectively (20°C and pH 7.3). Co-occurrence of nitrate-dependent Fe2+ oxidation and the anammox reaction decreased the molar ratios of consumed NO2? to consumed NH4+ (?NO2?/?NH4+) and produced NO3? to consumed NH4+ (?NO3?/?NH4+). These reactions are preferable to the application of anammox processes for wastewater treatment. PMID:23624480

Oshiki, M.; Ishii, S.; Yoshida, K.; Fujii, N.; Ishiguro, M.; Satoh, H.

2013-01-01

168

Experimental modelling of Calcium carbonate precipitation in the presence of phototrophic anaerobic bacteria Rhodovulum sp.  

NASA Astrophysics Data System (ADS)

Carbonate biomineralization is considered as one of the main natural processes controlling CO2 levels in the atmosphere both in the past and at present time. Haloalcaliphilic Rhodovulum sp. A-20s isolated from soda lake in southern Siberia and halophilic neutrophilic Rhodovulum sp. S-1765 isolated from hypersaline water body in Crimea steppe represent a large group of phototrophic bacteria likely to be involved in CaCO3 formation in soda and saline lakes. These bacteria use organic substrates for non-oxygenic photosynthesis and thus may mediate CaCO3 precipitation without CO2 consumption in highly-saline, highly-alkaline, NaHCO3-rich solutions. In order to provide the link between surface properties of bacteria and their ability to precipitate Ca carbonate, we used a combination of electrophoretic mobility measurements, surface titration and Ca ion adsorption using dead (autoclaved), inactivated (NaN3 - treated) and live cells at 25 °C as a unction of pH (3-11) and NaCl concentrations (0.01, 0.1, 0.5 M). Zeta potential of both bacteria is identical for active, NaN3-inactivated and dead cells at high ionic strength (0.5 M NaCl). The pH of isoelectric point is below 3 and zeta-potential decreases or remain negative up to pH 11. However, at lower ionic strength (0.1 M and 0.01 M NaCl) for live cells the potential increases towards positive values in the alkaline solutions (pH of 9 to 10). Similar to previous results on cyanobacteria (Martinez et al., 2009) there is a net increase in zeta-potential towards more positive values at pH = 10.4 for active cells. In order to better understand this phenomenon, experiments with different concentration of Ca2+ and HCO3- ions as well as experiments with live cultures in the darkness have been carried out. The presence in solution of Ca2+ (0.01 and 0.001 M) and the absence of light in experiment do not change significantly the potential of the cells. However, the presence in solution of HCO3- strongly reduces the zeta-potential of the cells. To characterise the link between the rate of bacterial growth (biomass production) and the rate of CaCO3 precipitation, batch kinetic experiments were performed. These experiments were carried out in closed (anaerobic) bottles with initial concentration of calcium from 1 to 20 mM and from 5 to 20 mM bicarbonate. The biomass of cells, pH, [Ca2+] and [Alk] were measured as a function of time. Blank experiments (without cell or autoclaved cells) were always carried out. We found that the optimal conditions for both CaCO3 precipitation and biomass increase for the culture Rhodovulum sp. A-20s, is calcium concentration of 3 mM, whatever the concentration of bicarbonate (5, 10, 15 mM). Note also that for calcium concentration higher than 3 mM, the biomass production decreases. In the case of strictly anaerobic Rhodovulum sp. S-1765 bacteria, the optimal conditions for calcium carbonate precipitation is observed for the bicarbonate concentration of 10 mM, whatever the calcium concentration (3, 5, 10 mM). Overall, the present study allows quantitative modeling of bacterially-induced CaCO3 precipitation. It helps to distinguish between the effect of cell surface functional groups, surface electrical charge, soluble organic matter and metabolic change of solution pH on the rate and nature of precipitating calcium carbonate solid phase.

Bundeleva, Irina; Shirokova, Liudmila; Benezeth, Pascale; Pokrovsky, Oleg; Kompantseva, Elena

2010-05-01

169

Prevalence and persistence of potentially pathogenic and antibiotic resistant bacteria during anaerobic digestion treatment of cattle manure.  

PubMed

Anaerobic digestion figures as a sustainable alternative to avoid discharge of cattle manure in the environment, which results in biogas and biofertilizer. Persistence of potentially pathogenic and drug-resistant bacteria during anaerobic digestion of cattle manure was evaluated. Selective cultures were performed for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC). Antimicrobial susceptibility patterns were determined and a decay of all bacterial groups was observed after 60days. Multidrug-resistant bacteria were detected both the influent and effluent. GPC, the most prevalent group was highly resistant against penicillin and levofloxacin, whereas resistance to ampicillin, ampicillin-sulbactam and chloramphenicol was frequently observed in the ENT and NFR groups. The data point out the need of discussions to better address management of biodigesters and the implementation of sanitary and microbiological safe treatments of animal manures to avoid consequences to human, animal and environmental health. PMID:24374028

Resende, Juliana Alves; Silva, Vânia Lúcia; de Oliveira, Tamara Lopes Rocha; de Oliveira Fortunato, Samuel; da Costa Carneiro, Jailton; Otenio, Marcelo Henrique; Diniz, Cláudio Galuppo

2014-02-01

170

A comparison of magnetite particles produced anaerobically by magnetotactic and dissimilatory iron-reducing bacteria  

SciTech Connect

The authors compare the magnetic properties of fine-grained magnetite produced by two newly isolated anaerobic bacteria, a magnetotactic bacterium (MV-1) and a dissimilatory iron-reducing bacterium (GS-15). Although room-temperature magnetic properties are generally different between the two microorganisms, MV-1 and GS-15 magnetites can be most easily distinguished by the temperature variation of saturation remanence obtained at liquid helium temperatures. Magnetite produced by MV-1 displays a sharp discontinuity in intensity at 100 K related to the Verwey transition. Magnetite produced by GS-15 displays a gradual decrease in intensity with temperature due to the progressive unblocking of magnetization. The differing behavior is due exclusively to different grain size distributions produced by these microorganisms. MV-1 produces magnetite with a narrow grain size distribution that is within the stable single domain size range at room temperature and below. GS-15 produces magnetite with a wide grain size distribution extending into the superparamagnetic (SPM) size range. Results show that a substantial fraction of particles produced by GS-15 are SPM at room temperature.

Moskowitz, B.M. (Univ. of California, Davis (USA)); Frankel, R.B. (California Polytechnic State Univ., San Luis Obispo (USA)); Bazylinski, D.A.; Jannasch, H.W. (Woods Hole Oceanographic Institution, MA (USA)); Lovley, D.R.

1989-07-01

171

Antimicrobial activity of some Pacific Northwest woods against anaerobic bacteria and yeast.  

PubMed

Extracts of woods commonly used for animal bedding were tested for antimicrobial activity. Essential oils from Alaska cedar (Chamaecyparis nootkatensis), western juniper (Juniperus occidentalis) and old growth Douglas fir (Pseudotsuga menziesii) as well as methanol extracts of wood from these trees plus western red cedar (Thuja plicata) and ponderosa pine (Pinus ponderosa) were tested for antimicrobial activity against anaerobic bacteria and yeast. The test microbes included Fusobacterium necrophorum, Clostridium perfringens, Actinomyces bovis and Candida albicans which are common to foot diseases and other infections in animals. The essential oils and methanol extracts were tested using a standardized broth assay. Only extracts of Alaska cedar and western juniper showed significant antimicrobial activity against each of the microbes tested. The essential oil of Douglas fir did show antimicrobial activity against A. bovis at the concentrations tested. The methanol extracts of the heartwood of Douglas fir and the sapwood of ponderosa pine showed no antimicrobial activity. The major chemical components of western juniper (cedrol and alpha- and beta-cedrene) and Alaska cedar (nootkatin) were also tested. In western juniper, alpha- and beta-cedrene were found to be active components. Nootkatin showed activity only against C. albicans. The inhibitory activity in Alaska cedar oil was high enough to justify further efforts to define the other chemical components responsible for the antimicrobial activity. PMID:11746838

Johnston, W H; Karchesy, J J; Constantine, G H; Craig, A M

2001-11-01

172

Introduction of anaerobic dechlorinating bacteria into soil slurry microcosms and nested-PCR monitoring.  

PubMed Central

Desulfomonile tiedjei and Desulfitobacterium dehalogenans were chosen as model bacteria to demonstrate the introduction of an anaerobic microbia reductive dechlorination activity into nonsterile soil slurry microcosms by inoculation. De novo 3-chlorobenzoate dechlorination activity was established with the bacterium D. tiedjei in microcosms normally devoid of this dechlorination capacity. The addition of D. tiedjei to microcosms supplemented with 20 mM pyruvate as the cosubstrate resulted in total biotransformation of 1.5 mM 3-chlorobenzoate within 7 days. The introduction of the bacterium Desulfitobacterium dehalogenans into nonsterile microcosms resulted in a shortening of the period required for dechlorination activity to be established. In microcosms inoculated with Desulfitobacterium dehalogenans, total degradation of 6 mM 3-chloro-4-hydroxy phenoxyacetic acid (3-Cl-4-OHPA) was observed after 4 days in contrast to the result in noninoculated microcosms, where the total degradation of 3-Cl-4-OHPA by indigenous microorganisms was observed after 11 days. Both externally introduced bacterial strains were detected in soil slurry microcosms by a nested-PCR methodology. PMID:9023963

el Fantroussi, S; Mahillon, J; Naveau, H; Agathos, S N

1997-01-01

173

Evaluation of VITEK Mass Spectrometry (MS), a Matrix-Assisted Laser Desorption Ionization Time-of-Flight MS System for Identification of Anaerobic Bacteria  

PubMed Central

Background By conventional methods, the identification of anaerobic bacteria is more time consuming and requires more expertise than the identification of aerobic bacteria. Although the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems are relatively less studied, they have been reported to be a promising method for the identification of anaerobes. We evaluated the performance of the VITEK MS in vitro diagnostic (IVD; 1.1 database; bioMérieux, France) in the identification of anaerobes. Methods We used 274 anaerobic bacteria isolated from various clinical specimens. The results for the identification of the bacteria by VITEK MS were compared to those obtained by phenotypic methods and 16S rRNA gene sequencing. Results Among the 249 isolates included in the IVD database, the VITEK MS correctly identified 209 (83.9%) isolates to the species level and an additional 18 (7.2%) at the genus level. In particular, the VITEK MS correctly identified clinically relevant and frequently isolated anaerobic bacteria to the species level. The remaining 22 isolates (8.8%) were either not identified or misidentified. The VITEK MS could not identify the 25 isolates absent from the IVD database to the species level. Conclusions The VITEK MS showed reliable identifications for clinically relevant anaerobic bacteria. PMID:25553283

Lee, Wonmok; Kim, Myungsook; Yong, Dongeun; Jeong, Seok Hoon; Chong, Yunsop

2015-01-01

174

Concerning the role of cell lysis-cryptic growth in anaerobic side-stream reactors: The single-cell analysis of viable, dead and lysed bacteria.  

PubMed

In the Anaerobic Side-Stream Reactor (ASSR), part of the return sludge undergoes alternating aerobic and anaerobic conditions with the aim of reducing sludge production. In this paper, viability, enzymatic activity, death and lysis of bacterial cells exposed to aerobic and anaerobic conditions for 16 d were investigated at single-cell level by flow cytometry, with the objective of contributing to the understanding of the mechanisms of sludge reduction in the ASSR systems. Results indicated that total and viable bacteria did not decrease during the anaerobic phase, indicating that anaerobiosis at ambient temperature does not produce a significant cell lysis. Bacteria decay and lysis occurred principally under aerobic conditions. The aerobic decay rate of total bacteria (bTB) was considered as the rate of generation of lysed bacteria. Values of bTB of 0.07-0.11 d(-1) were measured in anaerobic + aerobic sequence. The enzymatic activity was not particularly affected by the transition from anaerobiosis to aerobiosis. Large solubilisation of COD and NH4(+) was observed only under anaerobic conditions, as a consequence of hydrolysis of organic matter, but not due to cell lysis. The observations supported the proposal of two independent mechanisms contributing equally to sludge reduction: (1) under anaerobic conditions: sludge hydrolysis of non-bacterial material, (2) under aerobic conditions: bacterial cell lysis and oxidation of released biodegradable compounds. PMID:25725204

Foladori, P; Velho, V F; Costa, R H R; Bruni, L; Quaranta, A; Andreottola, G

2015-05-01

175

Inter-phylum HGT has shaped the metabolism of many mesophilic and anaerobic bacteria.  

PubMed

Genome sequencing has revealed that horizontal gene transfer (HGT) is a major evolutionary process in bacteria. Although it is generally assumed that closely related organisms engage in genetic exchange more frequently than distantly related ones, the frequency of HGT among distantly related organisms and the effect of ecological relatedness on the frequency has not been rigorously assessed. Here, we devised a novel bioinformatic pipeline, which minimized the effect of over-representation of specific taxa in the available databases and other limitations of homology-based approaches by analyzing genomes in standardized triplets, to quantify gene exchange between bacterial genomes representing different phyla. Our analysis revealed the existence of networks of genetic exchange between organisms with overlapping ecological niches, with mesophilic anaerobic organisms showing the highest frequency of exchange and engaging in HGT twice as frequently as their aerobic counterparts. Examination of individual cases suggested that inter-phylum HGT is more pronounced than previously thought, affecting up to ?16% of the total genes and ?35% of the metabolic genes in some genomes (conservative estimation). In contrast, ribosomal and other universal protein-coding genes were subjected to HGT at least 150 times less frequently than genes encoding the most promiscuous metabolic functions (for example, various dehydrogenases and ABC transport systems), suggesting that the species tree based on the former genes may be reliable. These results indicated that the metabolic diversity of microbial communities within most habitats has been largely assembled from preexisting genetic diversity through HGT and that HGT accounts for the functional redundancy among phyla. PMID:25314320

Caro-Quintero, Alejandro; Konstantinidis, Konstantinos T

2014-10-14

176

Removal of micropollutants, facultative pathogenic and antibiotic resistant bacteria in a full-scale retention soil filter receiving combined sewer overflow.  

PubMed

Combined sewer systems collect surface runoff as well as wastewater of industrial and domestic origin. During periods of heavy rainfall the capacity of the sewer system is exceeded and the overflow is discharged into receiving waters without any treatment. Consequently, combined sewer overflow (CSO) is considered as a major source of water pollution. This study investigates the effectiveness of a retention soil filter (RSF) for the removal of micropollutants as well as facultative pathogenic and antibiotic resistant bacteria from CSO. The removal of organic group parameters like total organic carbon was excellent and the removal efficiency for micropollutants of the RSF and the wastewater treatment plant (WWTP), which treats wastewater of the same origin during dry and normal weather conditions, was comparable. Compounds of high environmental concern like estrogens or certain pharmaceuticals, e.g. diclofenac, were completely eliminated or removed to a high degree during RSF passage. RSF treatment also reduced the number of E. coli, enterococci and staphylococci by 2.7, 2.2 and 2.4 log-units (median values), respectively. Obviously, some Staphylococcus species can better adapt to the conditions of the RSF than others as a shift of the abundance of the different species was observed when comparing the diversity of staphylococci obtained from the RSF influent and effluent. RSF treatment also decreased the absolute number of antibiotic resistant bacteria. The percentage of antibiotic resistant E. coli and staphylococci isolates also decreased during passage of the RSF, whereas the percentage of resistant enterococci did not change. For E. coli ampicillin and for enterococci and staphylococci erythromycin determined the antibiotic resistance level. The results demonstrate that RSFs can be considered as an adequate treatment option for CSO. The performance for the removal of micropollutants is comparable with a medium sized WWTP with conventional activated sludge treatment. The number of facultative pathogenic and antibiotic resistant bacteria was considerably decreased during RSF passage. However, as RSF effluents still contained antibiotic resistance genes and traces of micropollutants; receiving waters may still be at risk from negative environmental impacts. PMID:25479187

Scheurer, Marco; Heß, Stefanie; Lüddeke, Frauke; Sacher, Frank; Güde, Hans; Löffler, Herbert; Gallert, Claudia

2015-01-01

177

Aerobic Anoxygenic Phototrophic Bacteria  

PubMed Central

The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynthetically under anaerobic conditions. Aerobic anoxygenic phototrophic bacteria are classified in two marine (Erythrobacter and Roseobacter) and six freshwater (Acidiphilium, Erythromicrobium, Erythromonas, Porphyrobacter, Roseococcus, and Sandaracinobacter) genera, which phylogenetically belong to the ?-1, ?-3, and ?-4 subclasses of the class Proteobacteria. Despite this phylogenetic information, the evolution and ancestry of their photosynthetic properties are unclear. We discuss several current proposals for the evolutionary origin of aerobic phototrophic bacteria. The closest phylogenetic relatives of aerobic phototrophic bacteria include facultatively anaerobic purple nonsulfur phototrophic bacteria. Since these two bacterial groups share many properties, yet have significant differences, we compare and contrast their physiology, with an emphasis on morphology and photosynthetic and other metabolic processes. PMID:9729607

Yurkov, Vladimir V.; Beatty, J. Thomas

1998-01-01

178

Studies on Hydrogen Production by Photosynthetic Bacteria after Anaerobic Fermentation of Starch by a Hyperthermophile, Pyrococcus furiosus  

NASA Astrophysics Data System (ADS)

In order to establish the sequential hydrogen production from waste starch using a hyperthermophile, Pyrococcus furiosus, and a photosynthetic bacterium, basic studies were done. P. furiosus produced hydrogen and acetate by anaerobic fermentation at 90°C. A photosynthetic bacterium, Rhodobacter sphaeroides RV, was able to produce hydrogen from acetate under anaerobic and light conditions at 30°C. However, Rb. sphaeroides RV was not able to produce hydrogen from acetate in the presence of sodium chloride that was essential for the growth and hydrogen production of P. furiosus although it produced hydrogen from lactate at a reduced rate with 1% sodium chloride. A newly isolated strain, CST-8, from natural environment was, however, able to produce hydrogen from acetate, especially with 3 mM L-alanine and in the presence of 1% sodium chloride. The sequential hydrogen production with P. furiosus and salt-tolerant photosynthetic bacteria could be probable at least in the laboratory experiment scale.

Sugitate, Toshihiro; Fukatsu, Makoto; Ishimi, Katsuhiro; Kohno, Hideki; Wakayama, Tatsuki; Nakamura, Yoshihiro; Miyake, Jun; Asada, Yasuo

179

Inhibition of Methanogenesis by Methyl Fluoride: Studies of Pure and Defined Mixed Cultures of Anaerobic Bacteria and Archaea  

PubMed Central

Methyl fluoride (fluoromethane [CH(inf3)F]) has been used as a selective inhibitor of CH(inf4) oxidation by aerobic methanotrophic bacteria in studies of CH(inf4) emission from natural systems. In such studies, CH(inf3)F also diffuses into the anaerobic zones where CH(inf4) is produced. The effects of CH(inf3)F on pure and defined mixed cultures of anaerobic microorganisms were investigated. About 1 kPa of CH(inf3)F, similar to the amounts used in inhibition experiments, inhibited growth of and CH(inf4) production by pure cultures of aceticlastic methanogens (Methanosaeta spp. and Methanosarcina spp.) and by a methanogenic mixed culture of anaerobic microorganisms in which acetate was produced as an intermediate. With greater quantities of CH(inf3)F, hydrogenotrophic methanogens were also inhibited. At a partial pressure of CH(inf3)F of 1 kPa, homoacetogenic, sulfate-reducing, and fermentative bacteria and a methanogenic mixed culture of anaerobic microorganisms based on hydrogen syntrophy were not inhibited. The inhibition by CH(inf3)F of the growth and CH(inf4) production of Methanosarcina mazei growing on acetate was reversible. CH(inf3)F inhibited only acetate utilization by Methanosarcina barkeri, which is able to use acetate and hydrogen simultaneously, when both acetate and hydrogen were present. These findings suggest that the use of CH(inf3)F as a selective inhibitor of aerobic CH(inf4) oxidation in undefined systems must be interpreted with great care. However, by a careful choice of concentrations, CH(inf3)F may be useful for the rapid determination of the role of acetate as a CH(inf4) precursor. PMID:16535736

Janssen, P. H.; Frenzel, P.

1997-01-01

180

Biomarker Evidence for Widespread Anaerobic Methane Oxidation in Mediterranean Sediments by a Consortium of Methanogenic Archaea and Bacteria  

PubMed Central

Although abundant geochemical data indicate that anaerobic methane oxidation occurs in marine sediments, the linkage to specific microorganisms remains unclear. In order to examine processes of methane consumption and oxidation, sediment samples from mud volcanoes at two distinct sites on the Mediterranean Ridge were collected via the submersible Nautile. Geochemical data strongly indicate that methane is oxidized under anaerobic conditions, and compound-specific carbon isotope analyses indicate that this reaction is facilitated by a consortium of archaea and bacteria. Specifically, these methane-rich sediments contain high abundances of methanogen-specific biomarkers that are significantly depleted in 13C (?13C values are as low as ?95‰). Biomarkers inferred to derive from sulfate-reducing bacteria and other heterotrophic bacteria are similarly depleted. Consistent with previous work, such depletion can be explained by consumption of 13C-depleted methane by methanogens operating in reverse and as part a consortium of organisms in which sulfate serves as the terminal electron acceptor. Moreover, our results indicate that this process is widespread in Mediterranean mud volcanoes and in some localized settings is the predominant microbiological process. PMID:10698781

Pancost, Richard D.; Sinninghe Damsté, Jaap S.; de Lint, Saskia; van der Maarel, Marc J. E. C.; Gottschal, Jan C.

2000-01-01

181

Biomarker evidence for widespread anaerobic methane oxidation in Mediterranean sediments by a consortium of methanogenic archaea and bacteria  

SciTech Connect

Although abundant geochemical data indicate that anaerobic methane oxidation occurs in marine sediments, the linkage to specific microorganisms remains unclear. In order to examine processes of methane consumption and oxidation, sediment samples from mud volcanoes at two distinct sites on the Mediterranean consumption and oxidation, sediment samples from mud volcanoes at two distinct sites on the Mediterranean Ridge were collected via the submersible Nautile. Geochemical data strongly indicate that methane is oxidized under aerobic conditions, and compound-specific carbon isotope analyses indicate that methane is oxidized under anaerobic conditions, and compound-specific carbon isotope analyses indicate that this reaction is facilitated by a consortium of archaea and bacteria. Specifically, these methane-rich sediments contain high abundances of methanogen-specific biomarkers that are significantly depleted in {sup 13}C ({delta}{sup 13}C values are as low as {minus}95%). Biomarkers inferred to derive from sulfate-reducing bacteria and other heterotrophic bacteria are similarly depleted. Consistent with previous work, such depletion can be explained by consumption of {sup 13}C-depleted methane by methanogens operating in reverse and as part a consortium of organisms in which sulfate serves as the terminal electron acceptor. Moreover, their results indicate that this process is widespread in Mediterranean mud volcanoes and in some localized settings in the predominant microbiological process.

Pancost, R.D.; Damste, J.S.S.; Lint, S. De; Maarel, M.J.E.C. van der; Gottschal, J.C.

2000-03-01

182

Megasphaera indica sp. nov., an obligate anaerobic bacteria isolated from human faeces.  

PubMed

Two coccoid, non-motile, obligately anaerobic, Gram-stain-negative bacteria, occurring singly or in pairs, or as short chains, with a mean size of 1.4-2.5 µm were isolated from the faeces of two healthy human volunteers, aged 26 and 56 years, and were designated NMBHI-10(T) and BLPYG-7, respectively. Both the strains were affiliated to the sub-branch Sporomusa of the class Clostridia as revealed by 16S rRNA gene sequence analysis. The isolates NMBHI-10(T) and BLPYG-7 showed 99.1 and 99.2% 16S rRNA gene sequence similarity, respectively, with Megasphaera elsdenii JCM 1772(T). DNA-DNA hybridization and phenotypic analysis showed that both the strains were distinct from their closest relative, M. elsdenii JCM 1772(T) (42 and 53% DNA-DNA relatedness with NMBHI-10(T) and BLPYG-7, respectively), but belong to the same species (DNA-DNA relatedness of 80.9?% between the isolates). According to DNA-DNA hybridization results, the coccoid strains belong to the same genospecies, and neither is related to any of the recognized species of the genus Megasphaera. Strains NMBHI-10(T) and BLPYG-7 grew in PYG broth at temperatures of between 15 and 40 °C (optimum 37 °C), but not at 45 °C. The strains utilized a range of carbohydrates as sources of carbon and energy including glucose, lactose, cellobiose, rhamnose, galactose and sucrose. Glucose fermentation resulted in the formation of volatile fatty acids, mainly caproic acid and organic acids such as succinic acid. Phylogenetic analysis, specific phenotypic characteristics and/or DNA G+C content also differentiated the strains from each other and from their closest relatives. The DNA G+C contents of strains NMBHI-10(T) and BLPYG-7 are 57.7 and 54.9 mol%, respectively. The major fatty acids were 12 : 0 FAME and 17 : 0 CYC FAME. On the basis of these data, we conclude that strains NMBHI-10(T) and BLPYG-7 should be classified as representing a novel species of the genus Megasphaera, for which the name Megsphaera indica sp. nov. is proposed. The type strain is NMBHI-10(T) (?= DSM 25563(T)?= MCC 2481(T)). PMID:24711592

Lanjekar, V B; Marathe, N P; Ramana, V Venkata; Shouche, Y S; Ranade, D R

2014-07-01

183

A redox switch shapes the Lon protease exit pore to facultatively regulate proteolysis.  

PubMed

The Lon AAA+ protease degrades damaged or misfolded proteins in its intramolecular chamber. Its activity must be precisely controlled, but the mechanism by which Lon is regulated in response to different environments is not known. Facultative anaerobes in the Enterobacteriaceae family, mostly symbionts and pathogens, encounter both anaerobic and aerobic environments inside and outside the host's body, respectively. The bacteria characteristically have two cysteine residues on the Lon protease (P) domain surface that unusually form a disulfide bond. Here we show that the cysteine residues act as a redox switch of Lon. Upon disulfide bond reduction, the exit pore of the P-domain ring narrows by ?30%, thus interrupting product passage and decreasing activity by 80%; disulfide bonding by oxidation restores the pore size and activity. The redox switch (E°' = -227 mV) is appropriately tuned to respond to variation between anaerobic and aerobic conditions, thus optimizing the cellular proteolysis level for each environment. PMID:25383757

Nishii, Wataru; Kukimoto-Niino, Mutsuko; Terada, Takaho; Shirouzu, Mikako; Muramatsu, Tomonari; Kojima, Masaki; Kihara, Hiroshi; Yokoyama, Shigeyuki

2015-01-01

184

Reduction and Immobilization of Radionuclides and Toxic Metal Ions Using Combined Zero Valent Iron and Anaerobic Bacteria  

SciTech Connect

The use of zero valent iron, permeable reactive barriers (PRBs) for groundwater remediation continues to increase. AN exciting variation of this technology involves introducing anaerobic bacteria into these barriers so that both biological and abiotic pollutant removal processes are functional. This work evaluated the hypothesis that a system combining a mixed culture of sulfate reducing bacteria (SRB) with zero valent iron would have a greater cr(VI) removal efficiency and a greater total Cr(VI) removal capacity than a zero valent iron system without the microorganisms. Hence, the overall goal of this research was to compare the performance of these types of systems with regard to their Cr(VI) removal efficiency and total Cr(VI) removal capacity. Both batch and continuous flow reactor systems were evaluated.

Lenly J. Weathers; Lynn E. Katz

2002-05-29

185

Anaerobic Catabolism of Aromatic Compounds: a Genetic and Genomic View  

PubMed Central

Summary: Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach. PMID:19258534

Carmona, Manuel; Zamarro, María Teresa; Blázquez, Blas; Durante-Rodríguez, Gonzalo; Juárez, Javier F.; Valderrama, J. Andrés; Barragán, María J. L.; García, José Luis; Díaz, Eduardo

2009-01-01

186

Enumeration and Detection of Anaerobic Ferrous Iron-Oxidizing, Nitrate-Reducing Bacteria from Diverse European Sediments  

PubMed Central

Anaerobic, nitrate-dependent microbial oxidation of ferrous iron was recently recognized as a new type of metabolism. In order to study the occurrence of three novel groups of ferrous iron-oxidizing, nitrate-reducing bacteria (represented by strains BrG1, BrG2, and BrG3), 16S rRNA-targeted oligonucleotide probes were developed. In pure-culture experiments, these probes were shown to be suitable for fluorescent in situ hybridization, as well as for hybridization analysis of denaturing gradient gel electrophoresis (DGGE) patterns. However, neither enumeration by in situ hybridization nor detection by the DGGE-hybridization approach was feasible with sediment samples. Therefore, the DGGE-hybridization approach was combined with microbiological methods. Freshwater sediment samples from different European locations were used for enrichment cultures and most-probable-number (MPN) determinations. Bacteria with the ability to oxidize ferrous iron under nitrate-reducing conditions were detected in all of the sediment samples investigated. At least one of the previously described types of bacteria was detected in each enrichment culture. MPN studies showed that sediments contained from 1 × 105 to 5 × 108 ferrous iron-oxidizing, nitrate-reducing bacteria per g (dry weight) of sediment, which accounted for at most 0.8% of the nitrate-reducing bacteria growing with acetate. Type BrG1, BrG2, and BrG3 bacteria accounted for an even smaller fraction (0.2% or less) of the ferrous iron-oxidizing, nitrate-reducing community. The DGGE patterns of MPN cultures suggested that more organisms than those isolated thus far are able to oxidize ferrous iron with nitrate. A comparison showed that among the anoxygenic phototrophic bacteria, organisms that have the ability to oxidize ferrous iron also account for only a minor fraction of the population. PMID:9835573

Straub, Kristina L.; Buchholz-Cleven, Berit E. E.

1998-01-01

187

Identification of Anaerobic Bacteria by Bruker Biotyper Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry with On-Plate Formic Acid Preparation  

PubMed Central

Identification of anaerobic bacteria using phenotypic methods is often time-consuming; methods such as 16S rRNA gene sequencing are costly and may not be readily available. We evaluated 253 clinical isolates of anaerobic bacteria using the Bruker MALDI Biotyper (Bruker Daltonics, Billerica, MA) matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system with a user-supplemented database and an on-plate formic acid-based preparation method and compared results to those of conventional identification using biochemical testing or 16S rRNA gene sequencing. A total of 179 (70.8%) and 232 (91.7%) isolates were correctly identified to the species and genus levels, respectively, using manufacturer-recommended score cutoffs. MALDI-TOF MS offers a rapid, inexpensive method for identification of anaerobic bacteria. PMID:23254126

Schmitt, Bryan H.; Cunningham, Scott A.; Dailey, Aaron L.; Gustafson, Daniel R.

2013-01-01

188

Role of Anaerobic Ciliates in Planktonic Food Webs: Abundance, Feeding, and Impact on Bacteria in the Field  

PubMed Central

We studied the dynamics of two populations of anaerobic ciliates, Plagiopyla sp. and Metopus sp., and of their potential prey, heterotrophic and phototrophic purple bacteria, in Lake Cisó throughout a 1-year cycle. The abundance of both ciliates was very low (less than 2 individuals per ml). During mixing, Plagiopyla ciliates exhibited high clearance rates (about 100 nl ciliate-1 h-1), its integrated abundance increased with a net doubling time of 47 days, and its potential doubling times, as calculated from the number of bacteria consumed, ranged between 5 and 8 days. During stratification, the activity of Plagiopyla ciliates was reduced and the population decreased; this was related to the higher amounts of sulfide present. The impact of predation by the Plagiopyla population on bacterioplankton was found to be insignificant, less than 0.1% of bacterial biomass consumed per day. Thus, anaerobic ciliates cannot control the bacterioplankton in Lake Cisó because of both the low abundance over the period studied and the low feeding rates during certain periods. A review of available field studies suggests that this conclusion can be extrapolated to most other anoxic systems. PMID:16349239

Massana, Ramon; Pedrós-Alió, Carlos

1994-01-01

189

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?

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

2013-05-01

190

Anaerobic Oxidation of o-Xylene, m-Xylene, and Homologous Alkylbenzenes by New Types of Sulfate-Reducing Bacteria  

PubMed Central

Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the ? subclass of the class Proteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum and Desulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, and o-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene, m-isoproyltoluene, benzoate, and m-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide. PMID:10049854

Harms, Gerda; Zengler, Karsten; Rabus, Ralf; Aeckersberg, Frank; Minz, Dror; Rosselló-Mora, Ramon; Widdel, Friedrich

1999-01-01

191

Anaerobic nitrite-dependent methane-oxidizing bacteria - novel participants in methane cycling of drained peatlands ecosystems  

NASA Astrophysics Data System (ADS)

Northern peatlands are one of the key sources of atmospheric methane. Process-based studies of methane dynamic are based on the hypothesis of the balance between microbial methane production and oxidation, but this doesn't explain all variations in and constraints on peatland CH4 emissions. One of the reasons for this discrepancy could be anaerobic methane oxidation (AOM) - the process which is still poorly studied and remained controversial. Very little is known about AOM in peatlands, where it could work as an important 'internal' sink for CH4. This lack of knowledge primarily originated from researchers who generally consider AOM quantitatively insignificant or even non-existent in northern peatland ecosystems. But not far ago, Smemo and Yavitt (2007) presented evidence for AOM in freshwater peatlands used indirect techniques including isotope dilution assays and selective methanogenic inhibitors. Nitrite-dependent anaerobic methane oxidation NC10 group bacteria (n-damo) were detected in a minerotrophic peatland in the Netherlands that is infiltrated by nitrate-rich ground water (Zhu et al., 2012). Present study represents the first, to our knowledge, characterization of AOM in human disturbed peatlands, including hydrological elements of artificial drainage network. The experiments were conducted with samples of peat from drained peatlands, as well as of water and bottom sediments of ditches from drained Dubnensky mire massif, Moscow region (Chistotin et al., 2006; Sirin et al., 2012). This is the key testing area of our research group in European part of Russia for the long-term greenhouse gases fluxes measurements supported by testing physicochemical parameters, intensity and genomic diversity of CH4-cycling microbial communities. Only in sediments of drainage ditches the transition anaerobic zone was found, where methane and nitrate occurred, suggested the possible ecological niche for n-damo bacteria. The NC10 group methanotrophs were analyzed by PCR amplification of 16S rRNA (Ettwig et al. 2009) and pmoA (Luesken et al. 2011) genes followed by construction of clone libraries. Phylogenetic analysis revealed only one n-damo bacterium distantly related to uncultured anaerobic methanotrophs found in situ. It may represent a new cluster of NC10 bacteria with an identity of less than 96 and 86% to the 16S rRNA and pmoA genes of "Ca. Methylomirabilis oxyfera," respectively. An enrichment of nitrite-reducing methanotrophic NC10 bacteria was successfully obtained from this sample in a static anaerobic culture with methane and nitrite at an in situ pH of 6.3. The bacterial abundance in enrichment was estimated using quantitative PCR and FISH (DBACT-0193-a-A probe) analysis and was found to increase up to 10 times for 120 days. The results of this study expand our knowledge of the diversity and distribution of NC10 bacteria in the environment and their potential contribution to nitrogen and methane cycles in northern peatland ecosystems. We think that AOM may be more active in anthropogenic disturbed peatlands with greater supply of elements that could potentially serve as electron acceptors. In spite of generally low concentration, seasonal increases in nitrate content in drained peatlands may work as an important control of CH4 fluxes. The study was partially supported by RFBR research project # 12-05-01029_a.

Kravchenko, Irina; Sukhacheva, Marina; Menko, Ekaterina; Sirin, Andrey

2014-05-01

192

Evaluation of two media for antibiotic susceptibility testing of anaerobic bacteria using the receiver operating characteristic procedure.  

PubMed

Wilkins-Chalgren agar and Meat-Yeast agar were evaluated as media for antibiotic susceptibility testing using 112 anaerobic bacterial strains. The results obtained with the two media using the diffusion method were compared with those obtained by the dilution method as reference method. The results were analyzed by the receiver operating characteristic (ROC) procedure allowing a graphic representation of sensitivity and specificity of the technique for each cut-off value. The area under the ROC curves was calculated to compare the accuracy of the two methods. Six antibiotics were tested including amoxicillin, cefoxitin, piperacillin, doxycycline and clindamycin. For amoxicillin and clindamycin, the two methods showed a high and identical discriminative power for distinguishing susceptible bacteria from the others. Diffusion in Wilkins-Chalgren agar appeared better than diffusion in Meat-Yeast agar for separating resistant bacteria from bacteria of intermediate susceptibility (amoxicillin p less than 0.005; clindamycin p less than 0.04). For other drugs, diffusion in Wilkins-Chalgren agar always had a discriminative power higher than that obtained with diffusion in Meat-Yeast agar for separating susceptible bacteria from the others (cefoxitin p less than 0.0005; piperacillin p less than 0.02; doxycycline p less than 0.05). The Wilkins-Chalgren agar medium thus appeared superior to the Meat-Yeast agar medium using the ROC evaluation method, which would deserve wider utilization in the field of microbiology. PMID:2226495

Castel, O; Grollier, G; Agius, G; Toullat, G; de Rautlin de la Roy, Y

1990-09-01

193

Species Identification of Clinical Isolates of Anaerobic Bacteria: a Comparison of Two Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Systems ?  

PubMed Central

We compared two matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) systems (Shimadzu/SARAMIS and Bruker) on a collection of consecutive clinically important anaerobic bacteria (n = 290). The Bruker system had more correct identifications to the species level (67.2% versus 49.0%), but also more incorrect identifications (7.9% versus 1.4%). The system databases need to be optimized to increase identification levels. However, MALDI-TOF MS in its present version seems to be a fast and inexpensive method for identification of most clinically important anaerobic bacteria. PMID:21998433

Justesen, Ulrik Stenz; Holm, Anette; Knudsen, Elisa; Andersen, Line Bisgaard; Jensen, Thøger Gorm; Kemp, Michael; Skov, Marianne Nielsine; Gahrn-Hansen, Bente; Møller, Jens Kjølseth

2011-01-01

194

One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production  

SciTech Connect

This reporting period, progress is reported on the following: metabolic pathway of solvent production in B. methylotrophicum; the biochemical mechanism for metabolic regulation of the succinate fermentation; models to understand the physiobiochemical function of formate metabolism in anaerobes and; models for understanding the influence of low pH on one carbon metabolism. (CBS)

Zeikus, J.G.; Jain, M.K.

1992-01-01

195

Inhibition of Salmonella Typhimurium by Anaerobic Cecal Bacteria in Media Supplemented with Lactate and Succinate  

Technology Transfer Automated Retrieval System (TEKTRAN)

The ability of anaerobic cecal microflora of broilers to inhibit growth of Salmonella Typhimurium in media supplemented with lactate and succinate was examined. Cecal cultures were prepared by collecting ceca of processed broilers from a commercial processing facility, inoculating broth media with 1...

196

Group-specific PCR-RFLP and real-time PCR methods for detection and tentative discrimination of strictly anaerobic beer-spoilage bacteria of the class Clostridia  

Microsoft Academic Search

The strictly anaerobic brewery contaminants of the genera Pectinatus, Megasphaera, Selenomonas and Zymophilus in the class Clostridia constitute an important group of spoilage bacteria of unpasteurised, packaged beers. The aim of this study was to develop and evaluate group-specific PCR methods to detect and differentiate these bacteria in beer. A group-specific primer pair targeting a 342-bp variable region of the

Riikka Juvonen; Teija Koivula; Auli Haikara

2008-01-01

197

Bioaugmentation of anaerobic sequencing batch biofilm reactor (AnSBBR) with immobilized sulfate reducing bacteria (SRB) for the treatment of sulfate bearing chemical wastewater  

Microsoft Academic Search

Bioaugmentation strategy was applied to anaerobic sequencing batch biofilm reactor (AnSBBR) by inoculating with enriched sulfate reducing bacteria (SRB) in alginate-immobilized matrix for the enhanced treatment of sulfate bearing chemical wastewater. Non-augmented AnSBBR showed 35% of COD removal efficiency and 27% of sulfate reduction. Volatile fatty acid (VFA) accumulation was evidently observed during reactor operation indicating non-functioning of methanogenic bacteria

S. Venkata Mohan; N. Chandrasekhara Rao; K. Krishna Prasad; P. N. Sarma

198

In vitro activity of the tribactam GV104326 against gram-positive, gram-negative, and anaerobic bacteria.  

PubMed Central

GV104326 is the first member of a new class of antibiotics (tribactams) selected for development. It combines a particularly broad spectrum (including gram-negative and gram-positive aerobes and anaerobes) with high potency, resistance to beta-lactamases, and complete stability to dehydropeptidases. Comparative MICs were determined for GV104326 against 415 recent clinical isolates (including beta-lactamase producers), using representative antibacterial agents (imipenem, amoxicillin-clavulanic acid, cefpirome, ciprofloxacin, gentamicin, and erythromycin). GV104326 was particularly active against gram-positive bacteria; in general, its in vitro activity was equivalent to that of imipenem, equivalent to or better than that of amoxicillin-clavulanic acid, and superior to that of cefpirome, ciprofloxacin, and erythromycin. Against gram-negative bacteria, GV104326 possessed activity similar to that of imipenem and cefpirome against enterobacteria and Haemophilus spp. but its activity was superior to that of amoxicillin-clavulanic acid. GV104326 showed excellent antianaerobe activity. GV104326 was stable to all clinically relevant beta-lactamases and was rapidly lethal to susceptible bacteria. In Escherichia coli, GV104326 bound predominantly to PBPs 1a and 2 and at low concentrations osmotically stable round forms were observed. GV104326 showed an affinity for PBPs 2 and 4 of Staphylococcus aureus. PMID:7840571

Di Modugno, E; Erbetti, I; Ferrari, L; Galassi, G; Hammond, S M; Xerri, L

1994-01-01

199

The determination of the real nano-scale sizes of bacteria in chernozem during microbial succession by means of hatching of a soil in aerobic and anaerobic conditions  

NASA Astrophysics Data System (ADS)

M.A. Gorbacheva,L.M. Polyanskaya The Faculty of Soil Science, Moscow State University, Leninskie Gory, GSP-1, Moscow,119991,Russia In recent years there's been particular attention paid to the smallest life's forms- bacteria which size can be measured in nanometer. These are the forms of bacteria with diameter of 5-200 nm. Theoretical calculations based on the content of the minimum number of DNA, enzyme, lipids in and ribosome in cells indicates impossibility of existence of a living cells within diameter less than 300 nm. It is theoretically possible for a living cell to exist within possible diameter of approximately 140 nm. Using a fluorescence microscope there's been indicated in a number of samples from lakes, rivers, soil, snow and rain water that 200 nm is the smallest diameter of a living cell. Supposingly, such a small size of bacteria in soil is determined by natural conditions which limit their development by nutritious substances and stress-factors. Rejuvenescence of nanobacteria under unfavourable natural conditions and stress-factors is studied in laboratory environment. The object of the current study has become the samples of typical arable chernozem of the Central Chernozem State Biosphere Reserve in Kursk. The detailed morphological description of the soil profile and its basic analytical characteristics are widely represented in scientific publications. The soil is characterized by a high carbon content which makes up 3,96% ,3,8% , and 2,9% for the upper layers of the A horizon, and 0,79% for the layer of the B horizon. A microbial succession was studied under aerobic and anaerobic conditions by means of experiments with microcosms in upper A horizons and B horizon of a chernozem. The final aim is to identify the cells size of bacteria in aerobic and anaerobic soil conditions in chernozem during the microbial succession, by dampening and application of chitin by means of «cascade filtration» method. The study of the microcosms is important for understanding natural mechanisms in soil and will be useful for the development of new soil models in laboratory. Thus, by means of «cascade filtration» method there've been made some results on true size, quantity and biomass of bacteria. Development of a bacteria in various soil horizons and their layers in aerobic and anaerobic conditions and calculations of biomass of bacteria in upper layer horizon A and lower layer horizon B have also become the subjects of the studies. It was identified that the quantity of bacteria in aerobic conditions increase during the microbial succession while bacteria sized 230 and 380 nm were dominating. In anaerobic conditions the process of connecting cells sized 170 nm and bacteria is observed. Biomass of bacteria is higher in anaerobic conditions in upper layer horizon A because of elevated variety of bacteria. In horizon B in anaerobic conditions it is of maximum because of anaerobic situation in situ. Thus, distribution of bacteria's size depends on aeration of soil. That helps to acknowledge the receipt of theory of a great number of researchers about that fact that the size of bacteria in the soil in anaerobic conditions decrease under stress-factors. This work touches upon such a poorly investigated subject as nanobacteria in the soil. But this knowledge plays a significant role in land reclamation oil-cut and prognostication pollution of the soil by pathogenic bacteria.

Gorbacheva, M.

2012-04-01

200

Unusual anaerobic bacteria in keratitis after laser in situ keratomileusis: diagnosis using molecular biology methods.  

PubMed

Laser in situ keratomileusis (LASIK) was performed in the left eye of a 57-year-old man for residual ametropia after phacoemulsification. The patient was given topical tobramycin and a corticosteroid for 1 week postoperatively. Fifteen days later, he developed 3 corneal infiltrates beneath the flap with a gas bubble, suggesting an anaerobic infection. Tobramycin and ofloxacin were administered every 2 hours, but the condition worsened. Corneal scrapings were taken from beneath the flap for microbiological cultures and a polymerase chain reaction (PCR) test. The PCR amplification was negative for fungi and mycobacteria and positive for bacterial DNA. Sequence analysis showed Propionibacterium granulosum as the causal agent, but cultures were negative. Treatment with vancomycin and cefazolin led to clinical improvement, with resolution of corneal infiltrates. Anaerobic microorganisms can cause keratitis after LASIK. Polymerase chain reaction amplification and DNA typing can help detect microorganisms involved in these ocular infections. PMID:15313309

Ferrer, Consuelo; Rodríguez-Prats, Jose L; Abad, José L; Alió, Jorge L

2004-08-01

201

Bacteria and archaea involved in anaerobic digestion of distillers grains with solubles  

Microsoft Academic Search

Cereal distillers grains, a by-product from bioethanol industry, proved to be a suitable feedstock for biogas production in\\u000a laboratory scale anaerobic digesters. Five continuously stirred tank reactors were run under constant conditions and monitored\\u000a for biogas production and composition along with other process parameters. Iron additives for sulfide precipitation significantly\\u000a improved the process stability and efficiency, whereas aerobic pretreatment of

Ayrat M. Ziganshin; Thomas Schmidt; Frank Scholwin; Olga N. Il’inskaya; Hauke Harms; Sabine Kleinsteuber

2011-01-01

202

Remediation of polychlorinated biphenyl impacted sediment by concurrent bioaugmentation with anaerobic halorespiring and aerobic degrading bacteria  

PubMed Central

Bioremediation of sediments contaminated with commercial PCBs is potentially achievable by the sequential activity of anaerobic halorespiration to convert higher chlorinated congeners to less chlorinated congeners that are susceptible to aerobic respiratory degradation. The efficacy of bioaugmentation with anaerobic halorespiring “Dehalobium chlorocoercia” DF1 and aerobic Burkholderia xenovorans LB400 added concurrently with GAC as a delivery system was determined in 2-liter laboratory mesocosms containing weathered Aroclor-contaminated sediment from Baltimore Harbor, MD. The greatest effect was seen in the mesocosm bioaugmented with both DF1 and LB400 together, which resulted in an 80% decrease by mass of PCBs, from 8 mg/kg to less than 2 mg/kg after 120 days. There was no significant increase in lesser-chlorinated congeners, indicating that both anaerobic dechlorination by DF1 and aerobic degradation by LB400 occurred. In contrast, non-bioaugmented controls containing filtered culture supernatant showed only 25% decrease in total levels of PCBs after 365 days, which was likely due to biostimulation of the indigenous population by the medium. Direct colony counts and molecular analysis targeting a putative reductive dehalogenase gene of D. chlorocoercia, or the bphA gene of LB400 showed the presence of viable DF1 and LB400 in bioaugmented mesocosms after 365 days, indicating that both non-indigenous strains were sustainable within the indigenous microbial community. These results suggest that an in situ treatment employing the simultaneous application of anaerobic and aerobic microorganisms could be an effective, environmentally sustainable strategy to reduce PCBs levels in contaminated sediment. PMID:23463900

Payne, Rayford B.; Fagervold, Sonja K.; May, Harold D.; Sowers, Kevin R.

2013-01-01

203

The role of anaerobic bacteria in upper respiratory tract and other head and neck infections  

Microsoft Academic Search

Anaerobes are common pathogens in chronic upper respiratory tract and head and neck infections. They can be recovered in chronic\\u000a otitis media and sinusitis, play a role in tonsillitis, and predominate in complications of these infections, causing deep\\u000a oral and neck infections and abscesses. In addition to their direct pathogenicity, they play an indirect role through the\\u000a production of the

Itzhak Brook

2007-01-01

204

Anaerobic and aerobic bacteriology of the saliva and gingiva from 16 captive Komodo dragons (Varanus komodoensis): new implications for the "bacteria as venom" model.  

PubMed

It has been speculated that the oral flora of the Komodo dragon (Varanus komodoensis) exerts a lethal effect on its prey; yet, scant information about their specific oral flora bacteriology, especially anaerobes, exists. Consequently, the aerobic and anaerobic oral bacteriology of 16 captive Komodo dragons (10 adults and six neonates), aged 2-17 yr for adults and 7-10 days for neonates, from three U.S. zoos were studied. Saliva and gingival samples were collected by zoo personnel, inoculated into anaerobic transport media, and delivered by courier to a reference laboratory. Samples were cultured for aerobes and anaerobes. Strains were identified by standard methods and 16S rRNA gene sequencing when required. The oral flora consisted of 39 aerobic and 21 anaerobic species, with some variation by zoo. Adult dragons grew 128 isolates, including 37 aerobic gram-negative rods (one to eight per specimen), especially Enterobacteriaceae; 50 aerobic gram-positive bacteria (two to nine per specimen), especially Staphylococcus sciuri and Enterococcusfaecalis, present in eight of 10 and nine of 10 dragons, respectively; and 41 anaerobes (one to six per specimen), especially clostridia. All hatchlings grew aerobes but none grew anaerobes. No virulent species were isolated. As with other carnivores, captive Komodo oral flora is simply reflective of the gut and skin flora of their recent meals and environment and is unlikely to cause rapid fatal infection. PMID:23805543

Goldstein, Ellie J C; Tyrrell, Kerin L; Citron, Diane M; Cox, Cathleen R; Recchio, Ian M; Okimoto, Ben; Bryja, Judith; Fry, Bryan G

2013-06-01

205

Identification of anaerobic arsenite-oxidizing and arsenate-reducing bacteria associated with an alkaline saline lake in Khovsgol, Mongolia.  

PubMed

Microbial arsenic transformation pathways associated with a saline lake located in northern Mongolia were examined using molecular biological and culturing approaches. Bacterial 16S rRNA gene sequences recovered from saline lake sediments and soils were affiliated with haloalkaliphiles, including Bacillus and Halomonas spp. Diverse sequences of arsenate respiratory reductase (arrA) and a new group of arsenite oxidase (arxA) genes were also identified. Pure cultures of arsenate-reducing Nitrincola strain and anaerobic arsenite-oxidizing Halomonas strain were isolated. The chemoorganotrophic Halomonas strain contains arxA gene similar to that of a chemoautotrophic arsenite-oxidizing Alkalilimnicola ehrlichii strain MLHE-1. These results revealed the diversity of arsenic transformation pathways associated with a geographically distinct saline system and the potential contribution of arx-dependent arsenite oxidation by heterotrophic bacteria. PMID:25646538

Hamamura, Natsuko; Itai, Takaaki; Liu, Yitai; Reysenbach, Anna-Louise; Damdinsuren, Narantuya; Inskeep, William P

2014-10-01

206

The influence of incubation time, sample preparation and exposure to oxygen on the quality of the MALDI-TOF MS spectrum of anaerobic bacteria.  

PubMed

With matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), bacteria can be identified quickly and reliably. This accounts especially for anaerobic bacteria. Because growth rate and oxygen sensitivity differ among anaerobic bacteria, we aimed to study the influence of incubation time, exposure to oxygen and sample preparation on the quality of the spectrum using the Bruker system. Also, reproducibility and inter-examiner variability were determined. Twenty-six anaerobic species, representing 17 genera, were selected based on gram-stain characteristics, growth rate and colony morphology. Inter-examiner variation showed that experience in the preparation of the targets can be a significant variable. The influence of incubation time was determined between 24 and 96 h of incubation. Reliable species identification was obtained after 48 h of incubation for gram-negative anaerobes and after 72 h for gram-positive anaerobes. Exposure of the cultures to oxygen did not influence the results of the MALDI-TOF MS identifications of all tested gram-positive species. Fusobacterium necrophorum and Prevotella intermedia could not be identified after >24 h and 48 h of exposure to oxygen, respectively. Other tested gram-negative bacteria could be identified after 48 h of exposure to oxygen. Most of the tested species could be identified using the direct spotting method. Bifidobacterium longum and Finegoldia magna needed on-target extraction with 70% formic acid in order to obtain reliable species identification and Peptoniphilus ivorii a full extraction. Spectrum quality was influenced by the amount of bacteria spotted on the target, the homogeneity of the smear and the experience of the examiner. PMID:25039504

Veloo, A C M; Elgersma, P E; Friedrich, A W; Nagy, E; van Winkelhoff, A J

2014-12-01

207

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria  

PubMed Central

Transition metals are known to cause toxic effects through their interaction with oxygen, but toxicity under anoxic conditions is poorly understood. Here we investigated the effects of iron (Fe) and copper (Cu) on the anaerobic growth and gene expression of the purple phototrophic bacterium Rhodopseudomonas palustris TIE-1. We found that Fe(II) and Cu(II) act synergistically to delay anaerobic growth at environmentally relevant metal concentrations. Cu(I) and Cu(II) had similar effects both alone and in the presence of ascorbate, a Cu(II) reductant, indicating that reduction of Cu(II) to Cu(I) by Fe(II) is not sufficient to explain the growth inhibition. Addition of Cu(II) increased the toxicity of Co(II) and Ni(II); in contrast, Ni(II) toxicity was diminished in the presence of Fe(II). The synergistic anaerobic toxicity of Fe(II) and Cu(II) was also observed for Escherichia coli MG1655, Shewanella oneidensis MR-1, and Rhodobacter capsulatus SB1003. Gene expression analyses for R. palustris identified three regulatory genes that respond to Cu(II) and not to Fe(II): homologs of cueR and cusR, two known proteobacterial copper homeostasis regulators, and csoR, a copper regulator recently identified in Mycobacterium tuberculosis. Two P-type ATPase efflux pumps, along with an FoF1 ATP synthase, were also upregulated by Cu(II) but not by Fe(II). An Escherichia coli mutant deficient in copA, cus, and cueO showed a smaller synergistic effect, indicating that iron might interfere with one or more of the copper homeostasis systems. Our results suggest that interactive effects of transition metals on microbial physiology may be widespread under anoxic conditions, although the molecular mechanisms remain to be more fully elucidated. PMID:23563938

Bird, Lina J.; Coleman, Maureen L.

2013-01-01

208

In Vitro Activities of Y-688, a New 7-Substituted Fluoroquinolone, against Anaerobic Bacteria  

PubMed Central

The in vitro activities of Y-688, a new 7-substituted fluoroquinolone derivative, against 317 nonduplicate anaerobic isolates were determined. Eighty-five percent of the Bacteroides fragilis group (n = 89) were inhibited by ?2 mg of Y-688 per liter, while 78, 100, 89, and 98% of gram-negative bacilli (n = 135), gram-positive cocci (n = 59), and non-spore-forming (n = 58) and spore-forming (n = 51) gram-positive bacilli, respectively, were inhibited by ?1 mg of Y-688 per liter. PMID:9527797

MacGowan, A. P.; Bowker, K. E.; Wootton, M.; Holt, H. A.; Reeves, D. S.

1998-01-01

209

Effect of pH and temperature on the sorption of Np and Pa to mixed anaerobic bacteria.  

PubMed

While considering the geological disposal of radioactive wastes, the behaviour of the radionuclide Np and its daughter element Pa was investigated in the presence of a mixture of anaerobic bacteria (MAB). Originally, MAB were used for the treatment of pulp and paper wastewater. The interaction between radionuclides and bacteria was evaluated by determining distribution coefficients (Kd) over 10 days and at 5 degrees C and 35 degrees C. Kd for Np at 35 degrees C after 5 days had a low value around 10(-2) After 10 days, however, Kd was > 100-fold higher. On the other hand, Kd at 5 degrees C was low (10(-2)) throughout, without any significant increase over time. The interaction between Pa and MAB was found to be stronger than that for Np, with Kd for Pa about 100 times higher. The Kd was controlled by some basic factors, the activity of MAB, the complexing capacity of MAB, and the chemical conditions in the solution such as pH and Eh. PMID:11545492

Sasaki, T; Kauri, T; Kudo, A

2001-10-01

210

Nitrate-dependent anaerobic ferrous oxidation (NAFO) by denitrifying bacteria: a perspective autotrophic nitrogen pollution control technology.  

PubMed

The nitrate-dependent anaerobic ferrous oxidation (NAFO) is an important discovery in the fields of microbiology and geology, which is a valuable biological reaction since it can convert nitrate into nitrogen gas, removing nitrogen from wastewater. The research on NAFO can promote the development of novel autotrophic biotechnologies for nitrogen pollution control and get a deep insight into the biogeochemical cycles. In this work, batch experiments were conducted with denitrifying bacteria as biocatalyst to investigate the performance of nitrogen removal by NAFO. The results showed that the denitrifying bacteria were capable of chemolithotrophic denitrification with ferrous salt as electron donor, namely NAFO. And the maximum nitrate conversion rates (qmax) reached 57.89 mg (g VSS d)?1, which was the rate-limiting step in NAFO. Fe/N ratio, temperature and initial pH had significant influences on nitrogen removal by NAFO process, and their optimal values were 2.0 °C, 30.15 °C and 8.0 °C, respectively. PMID:25461924

Zhang, Meng; Zheng, Ping; Wang, Ru; Li, Wei; Lu, Huifeng; Zhang, Jiqiang

2014-12-01

211

Use of Nucleic-Acid Homologies in the Taxonomy of Anaerobic Bacteria  

Microsoft Academic Search

Nucleic acid homology studies are providing a common base for establishing bacterial groups. Few phenotypic characteristics have consistently correlated with homology data among the various groups of organisms that we have investigated. However, there are correlations that are specific for a given group of bacteria such that nucleic-acid homology data can be used to select those phenotypic properties that will

JOHN L. JOHNSON

1973-01-01

212

Reduction of Antibiotic-Resistant Bacteria Present in Food Animal Manures by Composting and Anaerobic Digestion  

E-print Network

Reduction of Antibiotic-Resistant Bacteria Present in Food Animal Manures by Composting by any other drug. Human and animal resistance to antimicrobial drugs has developed against all of antimicrobial resistance not only poses a severe risk to the health and well-being of both humans and animals

Jones, Michelle

213

Evaluation of broth disk elution methods for susceptibility testing of anaerobic bacteria with the newer beta-lactam antibiotics.  

PubMed

Broth disk elution procedures represent one of the most practical means for clinical laboratories to perform routine antibiotic susceptibility tests on anaerobic bacteria. The accuracy of five disk elution test methods and media (including the one to be proposed by the National Committee for Clinical Laboratory Standards) was evaluated for the testing of newer beta-lactam antibiotics, including cefoperazone, cefotaxime, cefoxitin, ceftazidime, ceftizoxime, moxalactam, and piperacillin. Various numbers of antibiotic disks were used to achieve disk elution test concentrations which approximated the highest MIC termed susceptible by the Food and Drug Administration. A group of 88 anaerobes representing many different species was tested in parallel by the five disk elution methods and the National Committee for Clinical Laboratory Standards reference agar dilution procedure. Overall, full agreement between the reference agar dilution MICs and the disk elution category results was 88.3% for PRAS BHI, 84.5% for Schaedler, 85.7% for thioglycolate, and 87.4% for Wilkins-Chalgren broth. Essential agreement (+/- 1 twofold MIC increment from the disk elution concentration) was achieved with 94.6% of PRAS BHI tests, 94.3% of Schaedler tests, 93.6% of thioglycolate tests, and 95.7% of Wilkins-Chalgren tests. Due to growth failures with a number of isolates and difficulties in interpreting results, the use of Wilkins-West broth was discontinued after approximately one-half of the isolates had been tested. The majority of errors with all of the disk elution methods occurred with isolates (most notably members of the Bacteroides fragilis group) having MICs near the single test concentrations used in the disk methods. With the notable exception of tests for the B. fragilis group, the disk elution methods offered acceptable accuracy with the newer beta-lactam antibiotics tested in this study. PMID:3514661

Jorgensen, J H; Redding, J S; Howell, A W

1986-03-01

214

Characterization of plant polysaccharide- and mucin-fermenting anaerobic bacteria from human feces.  

PubMed Central

Organisms able to grow on arabinogalactan, pectin, xylan, wheat bran, guar, apple cell walls, and mucin were isolated by enrichment from human feces. The number of polysaccharide fermenters and the properties of the predominant bacteria varied between subjects. The ability to use one polysaccharide was not related to the ability to use others. Some organisms (e.g., Bacteroides spp.) isolated on other substrates also utilized mucin, but were not isolated in the mucin enrichment. The mucin fermenters isolated by enrichment had a very restricted ability to utilize complex polysaccharides and their constituent monosaccharides, suggesting that the presence of plant polysaccharides in the human colon is unlikely to prevent the use of colonic mucin as an energy source by bacteria. Characterization with a range of biochemical tests showed that many of the isolates, but especially the mucin fermenters, did not resemble organisms described previously. PMID:6093693

Bayliss, C E; Houston, A P

1984-01-01

215

Utilization of alkylbenzenes during anaerobic growth of pure cultures of denitrifying bacteria on crude oil  

SciTech Connect

Leakage from oil pipelines and underground fuel tanks may result in contamination of soils and deeper horizons. Even though the equilibrium partitioning of BTEX (benzene, toluene, ethylbenzene, and xylenes) between oil and water is largely on the side of the hydrophobic phase, BTEX exhibit a certain water solubility higher than other oil hydrocarbons. This study evaluates the growth of four strains of denitrifying bacteria on crude oil and the resulting, strain-specific depletion of alkylbenzenes.

Rabus, R.; Widdel, F. [Max-Planck-Institut fuer Marine Mikrobiologie, Bremen (Germany)

1996-04-01

216

Diversity of culturable psychrophilic and psychrotrophic anaerobic bacteria isolated from beef abattoirs and their environments.  

PubMed

This study identified 431 psychrophilic or psychrotrophic isolates from commercial Irish beef abattoir environments and "blown packs" of vacuum-packed beef, using PCR and 16S rRNA sequencing, and estimated their intraspecies genetic diversity using restriction fragment length polymorphism (RFLP) analysis and spacer region PCR (SR-PCR). Twenty-five species were identified in the 431 isolates, with the most frequently recovered species being Clostridium gasigenes (n=315), Clostridium estertheticum (n=17), and a potentially novel species designated strain TC1 (n=52). These species were previously found to be associated with a particular type of spoilage known as blown-pack spoilage (BPS), which occurs in chilled-stored (i.e., -1.5°C to 4°C) vacuum-packaged meat within 2 to 4 weeks and involves the production of large volumes of gas. Overall, the study demonstrates the considerable and not previously reported diversity of the anaerobic microflora in abattoirs and the presence of a wide range of organisms capable of causing BPS at chilled temperatures. PMID:21498765

Moschonas, G; Bolton, D J; McDowell, D A; Sheridan, J J

2011-07-01

217

Direct observation and quantification of extracellular long-range electron flow in anaerobic bacteria  

NASA Astrophysics Data System (ADS)

Some anaerobic microorganisms are capable of transporting electrons outside their cell to distant electron acceptors such as metals, minerals or partner species. Previous studies have focused primarily on transport over short distances (1 ?m) via diffusion of molecular intermediates, or alternatively via tunneling or thermally-activated hopping across biomolecules. However, we have found that Geobacter sulfurreducens can transport electrons over long distances (10 ?m) using pili filaments that show organic metal-like conductivity [1]. Pili also enable direct exchange of electrons among syntrophic Geobacter co-cultures [2]. In order to establish the physical principles underlying this remarkable electron transport, we have employed a novel scanning probe microscopy-based method to perform quantitative measurements of electron flow at a single cell level under physiological conditions. Using this nanoscopic approach, we have directly observed the propagation and distribution of injected electrons in individual native bacterial extracellular proteins. Our direct measurements demonstrate unambiguously for the first time that the pili of G. sulfurreducens are a novel class of electronically functional proteins that can sustain electron flow in a surprising manner that has not been observed previously in any other natural protein.[4pt] [1] Nature Nanotechnology, 6, 573 (2011)[0pt] [2] Science, 330, 1413 (2010)

Malvankar, Nikhil; Yalcin, Sibel; Vargas, Madeline; Tuominen, Mark; Lovley, Derek

2013-03-01

218

Diversity of Culturable Psychrophilic and Psychrotrophic Anaerobic Bacteria Isolated from Beef Abattoirs and Their Environments ?  

PubMed Central

This study identified 431 psychrophilic or psychrotrophic isolates from commercial Irish beef abattoir environments and “blown packs” of vacuum-packed beef, using PCR and 16S rRNA sequencing, and estimated their intraspecies genetic diversity using restriction fragment length polymorphism (RFLP) analysis and spacer region PCR (SR-PCR). Twenty-five species were identified in the 431 isolates, with the most frequently recovered species being Clostridium gasigenes (n = 315), Clostridium estertheticum (n = 17), and a potentially novel species designated strain TC1 (n = 52). These species were previously found to be associated with a particular type of spoilage known as blown-pack spoilage (BPS), which occurs in chilled-stored (i.e., ?1.5°C to 4°C) vacuum-packaged meat within 2 to 4 weeks and involves the production of large volumes of gas. Overall, the study demonstrates the considerable and not previously reported diversity of the anaerobic microflora in abattoirs and the presence of a wide range of organisms capable of causing BPS at chilled temperatures. PMID:21498765

Moschonas, G.; Bolton, D. J.; McDowell, D. A.; Sheridan, J. J.

2011-01-01

219

Diversity of Ferrous Iron-Oxidizing, Nitrate-Reducing Bacteria and their Involvement in Oxygen-Independent Iron Cycling  

Microsoft Academic Search

In previous studies, three different strains (BrG1, BrG2, and BrG3) of ferrous iron-oxidizing, nitrate-reducing bacteria were obtained from freshwater sediments. All three strains were facultative anaerobes and utilized a variety of organic substrates and molecular hydrogen with nitrate as electron acceptor. In this study, analyses of 16S rDNA sequences showed that strain BrG1 was affiliated with the genus Acidovorax, strain

Kristina L. Straub; Wilhelm A. Schönhuber; Berit E. E. Buchholz-Cleven; Bernhard Schink

2004-01-01

220

Genes for Uranium Bioremediation in the Anaerobic Sulfate-Reducing Bacteria  

SciTech Connect

Objective A: Electron transfer components necessary for uranium reduction. Objective B: Possible FNR-analog in the sulfate-reducing bacteria. Attempts to isolate FNR or FIKJ analogs from Desuflovibrio through the design of degenerate primers for amplification of portions of the genes has not been successful. In contrast, several amplicons have been generated for the genes encoding the regulators of two-component signal sequences. Since several global regulators fall into this class, we are attempting to obtain sufficient sequence information to indicate what metabolic pathways are affected by the regulators. Cloning and sequencing of two such amplicons has revealed that bona fide two-component regulators are present in Desulfovibrio.

Wall, Judy D.

1999-06-01

221

The incidence and significance of anaerobic bacteria in the equine uterus  

E-print Network

15 may have been encountered when Q~uomon~a ~acr ~in g was the etiological agent of endometritis (Ley 1981), as mares may develop subacute or chronic infections due to P~u~mogs bacteria with little change in the endometrium (Hughes ~t al. 1966a... on histories and evidence of endometritis and subfertility. The uterine lumens of all mares were aseptically swabbed for exfoliative cytology by placing a uterine culture swab between two sterile palpation sleeves. The recovered swabs were rolled onto...

Bolinger, Dean Roger

1987-01-01

222

Genes for Uranium Bioremediation in the Anaerobic Sulfate-Reducing Bacteria  

SciTech Connect

The objectives of the previous grant period were designed to explore the electron transport pathway employed by the sulfate-reducing bacteria (SRB) for the reduction of U(VI) to U(IV). More specifically experiments were designed to determine whether U(VI) reduction by members of the genus Desulfovibrio was mediated by a unique, dedicated reductase or occurred as a fortuitous reaction with a reductase naturally involved in alternative reduction processes. In addition, the regulation of the hierarchical expression of terminal electron acceptors (reductases) in the SRB was to be examined.

Wall, Judy D.

2001-06-01

223

Capacity of anaerobic bacteria from necrotic dental pulps to induce purulent infections.  

PubMed Central

Combinations of bacteria isolated from the root canals of teeth with necrotic pulps and periapical bone destruction were tested for their capacity to induce abscess formation and transmissible infections when inoculated subcutaneously into guinea pigs. Transmissible infections could be induced with combinations obtained from teeth with purulent apical inflammation, but not with combinations from symptomless teeth with chronic apical inflammation. All combinations which gave transmissible infections contained strains of Bacteroides melaninogenicus or B. asaccharolyticus (formerly B. melaninogenicus subsp. asaccharolyticus). The results suggest that purulent inflammation in the apical region in certain cases may be induced by specific combinations of bacteria in the root canal and that the presence of B. melaninogenicus or B. asaccharolyticus in such combinations is essential. However, with one exception, the strains needed the support of additional microorganisms to achieve pathogenicity. The results indicate that Peptostreptococcus micros was also essential. Histological sections of the lesions in the guinea pigs showed that all bacterial combinations induced acute inflammation with an accumulation of polymorphonuclear leukocytes and the formation of an abscess. However, the presence of B. melaninogenicus or B. asaccharolyticus in the combinations resulted in a failure of abscess resolution, with a gradually increaseing accumulation of polymorphonuclear leukocytes. Images PMID:489126

Sundqvist, G K; Eckerbom, M I; Larsson, A P; Sjögren, U T

1979-01-01

224

Removal of sulfate and heavy metals by sulfate reducing bacteria in short-term bench scale upflow anaerobic packed bed reactor runs  

Microsoft Academic Search

Mildly acidic metal (Cu, Zn, Ni, Fe, Al and Mg), arsenic and sulfate contaminated waters were treated, over a 14 day period at 25°C, in a bench-scale upflow anaerobic packed bed reactor filled with silica sand and employing a mixed population of sulfate-reducing bacteria (SRB). The activity of SRB increased the water pH from ?4.5 to 7.0, and enhanced the

Tony Jong; David L Parry

2003-01-01

225

Study of the In Vitro Activities of Rifaximin and Comparator Agents against 536 Anaerobic Intestinal Bacteria from the Perspective of Potential Utility in Pathology Involving Bowel Flora?  

PubMed Central

Rifaximin, ampicillin-sulbactam, neomycin, nitazoxanide, teicoplanin, and vancomycin were tested against 536 strains of anaerobic bacteria. The overall MIC of rifaximin at which 50% of strains were inhibited was 0.25 ?g/ml. Ninety percent of the strains tested were inhibited by 256 ?g/ml of rifaximin or less, an activity equivalent to those of teicoplanin and vancomycin but less than those of nitazoxanide and ampicillin-sulbactam. PMID:18955526

Finegold, S. M.; Molitoris, D.; Väisänen, M.-L.

2009-01-01

226

In Vitro Activity of TD-1792, a Multivalent Glycopeptide-Cephalosporin Antibiotic, against 377 Strains of Anaerobic Bacteria and 34 Strains of Corynebacterium Species  

PubMed Central

TD-1792 is a multivalent glycopeptide-cephalosporin heterodimer antibiotic with potent activity against Gram-positive bacteria. We tested TD-1792 against 377 anaerobes and 34 strains of Corynebacterium species. Against nearly all Gram-positive strains, TD-1792 had an MIC90 of 0.25 ?g/ml and was typically 3 to 7 dilutions more active than vancomycin and daptomycin. PMID:22290981

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

2012-01-01

227

Vertical Profiles of Community Abundance and Diversity of Anaerobic Methanotrophic Archaea (ANME) and Bacteria in a Simple Waste Landfill in North China.  

PubMed

Anaerobic methane oxidation (AMO) is considered to be an important sink of CH4 in habitats as marine sediments. But, few studies focused on AMO in landfills which may be an important sink of CH4 derived from waste fermentation. To show evidence of AMO and to uncover function anaerobic methanotroph (ANME) community in landfill, different age waste samples were collected in Jinqianpu landfill located in north China. Through high-throughput sequencing, Methanomicrobiales and Methanosarcinales archaea associated with ANME and reverse methanogenic archaea of Methanosarcina and Methanobacterium were detected. Sulfate-reducing bacteria (SRB) (Desulfobulbus and Desulfococcus) which could couple with ANME-conducting AMO were also found. But, the community structure of ANME had no significant difference with depths. From the results of investigation, we can come to a conclusion that sulfate-dependent anaerobic methane oxidation (SR-DAMO) would be the dominant AMO process in the landfill, while iron-dependent anaerobic methane oxidation (M/IR-DAMO) process was weak though concentration of ferric iron was large in the landfill. Denitrification-dependent anaerobic methane oxidation (NR-DAMO) was negative because of lack of nitrate and relevant function microorganisms in the landfill. Results also indicate that CH4 mitigation would have higher potential by increasing electron acceptor contents and promoting the growth of relevant function microorganisms. PMID:25561057

Dong, Jun; Ding, Linjie; Wang, Xu; Chi, Zifang; Lei, Jiansen

2015-03-01

228

Anaerobic hydrocarbon and fatty acid metabolism by syntrophic bacteria and their impact on carbon steel corrosion  

PubMed Central

The microbial metabolism of hydrocarbons is increasingly associated with the corrosion of carbon steel in sulfate-rich marine waters. However, how such transformations influence metal biocorrosion in the absence of an electron acceptor is not fully recognized. We grew a marine alkane-utilizing, sulfate-reducing bacterium, Desulfoglaeba alkanexedens, with either sulfate or Methanospirillum hungatei as electron acceptors, and tested the ability of the cultures to catalyze metal corrosion. Axenically, D. alkanexedens had a higher instantaneous corrosion rate and produced more pits in carbon steel coupons than when the same organism was grown in syntrophic co-culture with the methanogen. Since anaerobic hydrocarbon biodegradation pathways converge on fatty acid intermediates, the corrosive ability of a known fatty acid-oxidizing syntrophic bacterium, Syntrophus aciditrophicus was compared when grown in pure culture or in co-culture with a H2-utilizing sulfate-reducing bacterium (Desulfovibrio sp., strain G11) or a methanogen (M. hungatei). The instantaneous corrosion rates in the cultures were not substantially different, but the syntrophic, sulfate-reducing co-culture produced more pits in coupons than other combinations of microorganisms. Lactate-grown cultures of strain G11 had higher instantaneous corrosion rates and coupon pitting compared to the same organism cultured with hydrogen as an electron donor. Thus, if sulfate is available as an electron acceptor, the same microbial assemblages produce sulfide and low molecular weight organic acids that exacerbated biocorrosion. Despite these trends, a surprisingly high degree of variation was encountered with the corrosion assessments. Differences in biomass, initial substrate concentration, rates of microbial activity or the degree of end product formation did not account for the variations. We are forced to ascribe such differences to the metallurgical properties of the coupons. PMID:24744752

Lyles, Christopher N.; Le, Huynh M.; Beasley, William Howard; McInerney, Michael J.; Suflita, Joseph M.

2014-01-01

229

Taxonomic composition and physiological and biochemical properties of bacteria in the digestive tracts of earthworms  

NASA Astrophysics Data System (ADS)

Several hundred bacterial strains belonging to different taxa were isolated and identified from the digestive tracts of soil and compost earthworms. Some physiological and biochemical properties of the bacteria were characterized. The majority of intestinal bacteria in the earthworms were found to be facultative anaerobes. The intestinal isolates as compared to the soil ones had elevated activity of proteases and dehydrogenases. In addition, bacteria associated with earthworms' intestines are capable of growth on humic acids as a sole carbon source. Humic acid stimulated the growth of the intestinal bacteria to a greater extent than those of the soil ones. In the digestive tracts, polyphenol oxidase activity was found. Along with the data on the taxonomic separation of the intestinal bacteria, the features described testified to the presence of a group of bacteria in the earthworms intestines that is functionally characteristic and is different from the soil bacteria.

Byzov, B. A.; Tikhonov, V. V.; Nechitailo, T. Yu.; Demin, V. V.; Zvyagintsev, D. G.

2015-03-01

230

Dissimilatory Reduction of Elemental Selenium to Selenide in Sediments and Anaerobic Cultures of Selenium Respiring Bacteria  

NASA Astrophysics Data System (ADS)

Selenium contaminated environments often contain elemental Se (Se0) in their sediments that originates from dissimilatory reduction of Se oxyanions. The forms of Se in sedimentary rocks similarly contain high proportions of Se0, but much of the Se is also in the form of metal selenides, Se-2. It is not clear if the occurrence of these selenides is due to microbial reduction of Se0, or some other biological or chemical process. In this investigation we examined the possibility that bacterial respiratory reduction of Se0 to Se-2 could explain the presence of the latter species in sedimentary rocks. We conducted incubations of anoxic sediment slurries amended with different forms of Se0. High levels of Se0 (mM) were added to San Francisco Bay sediments in order to enhance the detection of soluble HSe-, which was precipitated with Cu2+ then redissolved and quantified by ICP-MS. Concentrations of HSe- were highest in live samples amended with red amorphous Se0 formed by either microbial reduction of Se+4 ("biogenic Se0") or by chemical oxidation of H2Se(g) ("chem. Se0"); very little HSe- was formed in those amended with black crystalline Se0, indicating the general lack of reactivity of this allotrope. Controls poisoned with 10% formalin did not produce HSe- from additions of chem. Se0. Reduction of both forms of red amorphous Se0 to HSe- occurred vigorously in growing cultures of Bacillus selenitireducens, an anaerobic halophile previously isolated from sediments of Mono Lake, CA. Up to 73% and 68% of red amorphous, biogenic Se0 or chem. Se0, respectively, was reduced to HSe- during growth of B. selenitireducens, (incubation time ~ 200 hrs): oxidation of lactate to acetate as well as cell density increases indicated that a dissimilatory reduction pathway was likely. Reduction was most enhanced when cells were previously grown on elemental sulfur or Se+4. In contrast to the growth experiments, washed cell suspensions of B. selenitireducens exhibited no HSe- production when amended with red amorphous or black Se0; however, they could convert up to 34% of added Se+4 to HSe- after its complete reduction to Se0 first occurred. These findings indicate that reduction of Se0 in sediments to HSe- or metal selenides is a bacterial dissimilatory processes, that explains the presence of selenides in some sedimentary rocks.

Herbel, M. J.; Switzer-Blum, J.; Oremland, R. S.

2001-12-01

231

Anaerobic wastewater treatment  

Microsoft Academic Search

The article reviews the present understanding of bacterial populations involved in anaerobic degradation of organic material into methane and CO2 (biogas); furthermore some recent process developments for anaerobic wastewater treatment are described. It could be demonstrated that at least three groups of bacteria are involved in methanogenesis. Hydrolytic and acidogenic bacteria first decompose the organic material into various organic acids,

H. Sahm

232

Anaerobic oxidation of ferrous iron by purple bacteria, a new type of phototrophic metabolism.  

PubMed Central

Anoxic iron-rich sediment samples that had been stored in the light showed development of brown, rusty patches. Subcultures in defined mineral media with ferrous iron (10 mmol/liter, mostly precipitated as FeCO3) yielded enrichments of anoxygenic phototrophic bacteria which used ferrous iron as the sole electron donor for photosynthesis. Two different types of purple bacteria, represented by strains L7 and SW2, were isolated which oxidized colorless ferrous iron under anoxic conditions in the light to brown ferric iron. Strain L7 had rod-shaped, nonmotile cells (1.3 by 2 to 3 microns) which frequently formed gas vesicles. In addition to ferrous iron, strain L7 used H2 + CO2, acetate, pyruvate, and glucose as substrate for phototrophic growth. Strain SW2 had small rod-shaped, nonmotile cells (0.5 by 1 to 1.5 microns). Besides ferrous iron, strain SW2 utilized H2 + CO2, monocarboxylic acids, glucose, and fructose. Neither strain utilized free sulfide; however, both strains grew on black ferrous sulfide (FeS) which was converted to ferric iron and sulfate. Strains L7 and SW2 grown photoheterotrophically without ferrous iron were purple to brownish red and yellowish brown, respectively; absorption spectra revealed peaks characteristic of bacteriochlorophyll a. The closest phototrophic relatives of strains L7 and SW2 so far examined on the basis of 16S rRNA sequences were species of the genera Chromatium (gamma subclass of proteobacteria) and Rhodobacter (alpha subclass), respectively. In mineral medium, the new isolates formed 7.6 g of cell dry mass per mol of Fe(II) oxidized, which is in good agreement with a photoautotrophic utilization of ferrous iron as electron donor for CO2 fixation. Dependence of ferrous iron oxidation on light and CO2 was also demonstrated in dense cell suspensions. In media containing both ferrous iron and an organic substrate (e.g., acetate, glucose), strain L7 utilized ferrous iron and the organic compound simultaneously; in contrast, strain SW2 started to oxidize ferrous iron only after consumption of the organic electron donor. Ferrous iron oxidation by anoxygenic phototrophs is understandable in terms of energetics. In contrast to the Fe3+/Fe2+ pair (E0 = +0.77 V) existing in acidic solutions, the relevant redox pair at pH 7 in bicarbonate-containing environments, Fe(OH)3 + HCO3-/FeCO3, has an E0' of +0.2 V. Ferrous iron at pH 7 can therefore donate electrons to the photosystem of anoxygenic phototrophs, which in purple bacteria has a midpoint potential around +0.45 V. The existence of ferrous iron-oxidizing anoxygenic phototrophs may offer an explanation for the deposition of early banded-iron formations in an assumed anoxic biosphere in Archean times. Images PMID:7811087

Ehrenreich, A; Widdel, F

1994-01-01

233

Potential Application of Anaerobic Extremophiles for Hydrogen Production  

NASA Technical Reports Server (NTRS)

During substrate fermentation many anaerobes produce the hydrogen as a waste product, which often regulates the growth of the cultures as an inhibitor. In nature the hydrogen is usually removed from the ecosystem due to its physical properties or by consumption of hydrogen by secondary anaerobes, which sometimes behave as competitors for electron donors as is seen in the classical example in anaerobic microbial communities via the interaction between methanogens and sulfate- or sulfur- reducers. It was demonstrated previously on mixed cultures of anaerobes at neutral pH that bacterial hydrogen production could provide an alternative energy source. But at neutral pH the original cultures can easily be contaminated by methanogens, a most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and the cultivation of human pathogens on a global scale is very dangerous. In our laboratory, experiments with obligately alkaliphilic bacteria that excrete hydrogen as the end metabolic product were performed at different temperature regimes. Mesophilic and moderately thermophilic bacterial cultures have been studied and compared for the most effective hydrogen production. For high-mineralized media with pH 9.5-10.0 not many methanogens are known to exist. Furthermore, the development of pathogenic contaminant microorganisms is virtually impossible: carbonate-saturated solutions are used as antiseptics in medicine. Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as most safe process for global Scale industry in future. Here we present experimental data on the rates of hydrogen productivity for mesophilic, alkaliphilic, obligately anaerobic bacterium Spirocheta americana ASpG1 and moderately thermophilic, alkaliphilic, facultative anaerobe Anoxybacillus pushchinoensis K1 and discuss the potential implications for alternative energy sources.

Pikuta, Elena V.; Hoover, Richard B.

2004-01-01

234

Anaerobic degradation of cyclohexane by sulfate-reducing bacteria from hydrocarbon-contaminated marine sediments  

PubMed Central

The fate of cyclohexane, often used as a model compound for the biodegradation of cyclic alkanes due to its abundance in crude oils, in anoxic marine sediments has been poorly investigated. In the present study, we obtained an enrichment culture of cyclohexane-degrading sulfate-reducing bacteria from hydrocarbon-contaminated intertidal marine sediments. Microscopic analyses showed an apparent dominance by oval cells of 1.5 × 0.8 ?m. Analysis of a 16S rRNA gene library, followed by whole-cell hybridization with group- and sequence-specific oligonucleotide probes showed that these cells belonged to a single phylotype, and were accounting for more than 80% of the total cell number. The dominant phylotype, affiliated with the Desulfosarcina-Desulfococcus cluster of the Deltaproteobacteria, is proposed to be responsible for the degradation of cyclohexane. Quantitative growth experiments showed that cyclohexane degradation was coupled with the stoichiometric reduction of sulfate to sulfide. Substrate response tests corroborated with hybridization with a sequence-specific oligonucleotide probe suggested that the dominant phylotype apparently was able to degrade other cyclic and n-alkanes, including the gaseous alkane n-butane. Based on GC-MS analyses of culture extracts cyclohexylsuccinate was identified as a metabolite, indicating an activation of cyclohexane by addition to fumarate. Other metabolites detected were 3-cyclohexylpropionate and cyclohexanecarboxylate providing evidence that the overall degradation pathway of cyclohexane under anoxic conditions is analogous to that of n-alkanes. PMID:25806023

Jaekel, Ulrike; Zedelius, Johannes; Wilkes, Heinz; Musat, Florin

2015-01-01

235

Novel chemolithotrophic, thermophilic, anaerobic bacteria Thermolithobacter ferrireducens gen. nov., sp. nov. and Thermolithobacter carboxydivorans sp. nov.  

PubMed

Three thermophilic strains of chemolithoautotrophic Fe(III)-reducers were isolated from mixed sediment and water samples (JW/KA-1 and JW/KA-2(T): Calcite Spring, Yellowstone N.P., WY, USA; JW/JH-Fiji-2: Savusavu, Vanu Levu, Fiji). All were Gram stain positive rods (approximately 0.5 x 1.8 microm). Cells occurred singly or in V-shaped pairs, and they formed long chains in complex media. All utilized H(2) to reduce amorphous iron (III) oxide/hydroxide to magnetite at temperatures from 50 to 75 degrees C (opt. approximately 73 degrees C). Growth occurred within the pH(60C) range of 6.5-8.5 (opt. pH(60C) 7.1-7.3). Magnetite production by resting cells occurred at pH(60C) 5.5-10.3 (opt. 7.3). The iron (III) reduction rate was 1.3 mumol Fe(II) produced x h(-1) x ml(-1) in a culture with 3 x 10(7) cells, one of the highest rates reported. In the presence or absence of H(2), JW/KA-2(T) did not utilize CO. The G + C content of the genomic DNA of the type strain is 52.7 +/- 0.3 mol%. Strains JW/KA-1 and JW/KA-2(T) each contain two different 16S rRNA gene sequences. The 16S rRNA gene sequences from JW/KA-1, JW/KA-2(T), or JW/JH-Fiji-2 possessed >99% similarity to each other but also 99% similarity to the 16S rRNA gene sequence from the anaerobic, thermophilic, hydrogenogenic CO-oxidizing bacterium 'Carboxydothermus restrictus' R1. DNA-DNA hybridization between strain JW/KA-2(T) and strain R1(T) yielded 35% similarity. Physiological characteristics and the 16S rRNA gene sequence analysis indicated that the strains represent two novel species and are placed into the novel genus Thermolithobacter within the phylum 'Firmicutes'. In addition, the levels of 16S rRNA gene sequence similarity between the lineage containing the Thermolithobacter and well-established members of the three existing classes of the 'Firmicutes' is less than 85%. Therefore, Thermolithobacter is proposed to constitute the first genus within a novel class of the 'Firmicutes', Thermolithobacteria. The Fe(III)-reducing Thermolithobacter ferrireducens gen. nov., sp. nov. is designated as the type species with strain JW/KA-2(T) (ATCC 700985(T), DSM 13639(T)) as its type strain. Strain R1(T) is the type strain for the hydrogenogenic, CO-oxidizing Thermolithobacter carboxydivorans sp. nov. (DSM 7242(T), VKM 2359(T)). PMID:17021657

Sokolova, T; Hanel, J; Onyenwoke, R U; Reysenbach, A-L; Banta, A; Geyer, R; González, J M; Whitman, W B; Wiegel, J

2007-01-01

236

Bio-beads with immobilized anaerobic bacteria, zero-valent iron, and active carbon for the removal of trichloroethane from groundwater.  

PubMed

Chlorinated hydrocarbons are the most common organic pollutants in groundwater systems worldwide. In this study, we developed bio-beads with immobilized anaerobic bacteria, zero-valent iron (ZVI), and activated carbon (AC) powder and evaluated their efficacy in removing 1,1,1-trichloroethane (TCA) from groundwater. Bio-beads were produced by polyvinyl alcohol, alginate, and AC powder. We found that the concentration of AC powder used significantly affected the mechanical properties of immobilized bio-beads and that 1.0 % (w/v) was the optimal concentration. The bio-beads effectively degraded TCA (160 mg L(-1)) in the anaerobic medium and could be reused up to six times. The TCA degradation rate of bio-beads was 1.5 and 2.3 times greater, respectively, than ZVI + AC treatment or microbes + AC treatment. Measuring FeS produced by microbial reactions indicated that TCA removal occurred via FeS-catalyzed dechlorination. Analysis of clonal libraries derived from bio-beads demonstrated that the dominant species in the community were Betaproteobacteria and Gammaproteobacteria, which may contribute to the long-term stability of ZVI reactivity during TCA dechlorination. This study shows that the combined use of immobilized anaerobic bacteria, ZVI, and AC in bio-beads is effective and practical for TCA dechlorination and suggests they may be applicable towards developing a groundwater treatment system for the removal of TCA. PMID:24906831

Zhou, Ya-Zhen; Yang, Jie; Wang, Xiao-Li; Pan, Yue-Qing; Li, Hui; Zhou, Dong; Liu, Yong-Di; Wang, Ping; Gu, Ji-Dong; Lu, Qiang; Qiu, Yue-Feng; Lin, Kuang-Fei

2014-10-01

237

Arsenic, Anaerobes, and Autotrophy.  

NASA Astrophysics Data System (ADS)

That microbes have resistance to the toxic arsenic oxyanions arsenite [As(III)] and arsenate [As(V)] has been recognized for some time. More recently it was shown that certain prokaryotes can demonstrate As- dependent growth by conserving the energy gained from the aerobic oxidation of As(III) to As(V), or from the reduction of As(V) to As(III) under anaerobic conditions. During the course of our field studies of two alkaline, hypersaline soda lakes (Mono Lake and Searles Lake, CA) we have discovered several new anaerobic chemo- and photo-autotrophic bacteria that can center their energy gain around the redox reactions between As(III) and As(V). Alkalilimnicola ehrlichii, isolated from the water column of Mono Lake is a nitrate-respiring, As(III)-oxidizing chemoautotroph of the gamma-proteobacteria that has a highly flexible metabolism. It can function either as a facultative anaerobe or as a chemo-autotroph, or as a heterotroph (Hoeft et al., 2007). In contrast, strain MLMS-1 of the delta-proteobacteria was also isolated from Mono Lake, but to date is the first example of an obligate As(V)-respirer that is also an obligate chemo-autotroph, gaining its energy via the oxidation of sulfide to sulfate (Hoeft et al., 2004). Strain SLAS-1, isolated from salt-saturated Searles Lake is a member of the Halananerobiales, and can either grow as a heterotroph (lactate e-donor) or chemo- autotroph (sulfide e-donor) while respiring As(V). The fact that it can achieve this feat at salt-saturation (~ 340 g/L) makes it a true extremophile (Oremland et. al., 2005). Finally, strain PHS-1 isolated from a hot spring on Paoha island in Mono Lake is the first example of a photosynthetic bacterium of the gamma- proteobacteria able to link its growth to As(III)-dependent anoxygenic photosynthesis (Kulp et al., 2008). These novel microbes give us new insights into the evolution of arsenic-based metabolism and their role in the biogeochemical cycling of this toxic element. Hoeft, S.E., et al. 2007. Int. J. Syst. Evol. Microbiol. 57: 514 - 512. Hoeft, S.E, et al. 2004. Appl. Environ. Microbiol. 70: 2741 - 2747. Oremland, R.S., et al. 2005. Science 308: 1305 - 1308. Kulp, T.R. et al. 2008. Science 321: 967 - 970.

Oremland, R. S.

2008-12-01

238

Natronincola ferrireducens sp. nov., and Natronincola peptidovorans sp. nov., new anaerobic alkaliphilic peptolytic iron-reducing bacteria isolated from soda lakes  

Microsoft Academic Search

Two novel strains of obligately alkaliphilic (pH 7.5–10.2, optimum pH 8.4–8.8) anaerobic spore-forming rod-shaped bacteria,\\u000a Z-0511 and Z-7031, were isolated from enrichment cultures obtained from the iron-reducing (Lake Khadyn, Tyva) and cellulolytic\\u000a (Lake Verkhnee Beloe, Buryatia) bacterial communities, respectively. The organisms ferment peptides and do not ferment proteins\\u000a and amino acids, with the exception of histidine and glutamate utilized by

T. N. Zhilina; D. G. Zavarzina; G. A. Osipov; N. A. Kostrikina; T. P. Tourova

2009-01-01

239

The anaerobic life of Bacillus subtilis: Cloning of the genes encoding the respiratory nitrate reductase system  

Microsoft Academic Search

The Gram-positive soil bacterium Bacillus subtilis, generally regarded as an aerobe, grows under strict anaerobic conditions using nitrate as an electron acceptor and should be designated as a facultative anaerobe. Growth experiments demonstrated a lag phase of 24 to 36 hours after the shift from aerobic, to the onset of anaerobic respiratory growth. Anaerobically adapted cells grew without further lag

Tamara Hoffmann; Barbara Troup; Alexandra Szabo; Christoph Hungerer; Dieter Jahn

1995-01-01

240

Comparison of the Use of the Halimeter and the Oral Chroma™ in the Assessment of the Ability of Common Cultivable Oral Anaerobic Bacteria to Produce Malodorous Volatile Sulfur Compounds from Cysteine and Methionine  

Microsoft Academic Search

Objective: To compare the use of the Halimeter and the Oral Chroma™ to assess the ability of common oral anaerobic bacteria isolated from the Kuwaiti population to produce volatile sulfur compounds (VSCs). Materials and Methods: Broth cultures of common anaerobes isolated from supragingival plaque were centrifuged and pellets resuspended in phosphate buffer (pH 7.7) with an optical density OD550 of

Nathanael O. Salako; Leeba Philip

2011-01-01

241

Ceftaroline plus Avibactam Demonstrates Bactericidal Activity against Pathogenic Anaerobic Bacteria in a One-Compartment In Vitro Pharmacokinetic/Pharmacodynamic Model  

PubMed Central

Anaerobic pathogens are often associated with polymicrobial infections, such as diabetic foot infections. Patients with these infections are often treated with broad-spectrum, multidrug therapies targeting resistant Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus, as well as Gram-negative bacteria and anaerobes. The broad-spectrum, non-beta-lactam, beta-lactamase inhibitor avibactam has been combined with ceftaroline and may provide a single-product alternative for complicated polymicrobial infections. We compared the activity of ceftaroline-avibactam (CPA) to that of ertapenem (ERT) against common anaerobic pathogens in an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model. Simulations of doses of ceftaroline-fosamil at 600 mg every 8 h (q8h) (maximum free drug concentration [fCmax], 17.04 mg/liter, and half-life [t1/2], 2.66 h) plus avibactam at 600 mg q8h (fCmax, 11.72 mg/liter, and t1/2, 1.8 h) and of ertapenem at 1 g q24h (fCmax, 13 mg/liter, and t1/2, 4 h) were evaluated against two strains of Bacteroides fragilis, one strain of Prevotella bivia, and one strain of Finegoldia magna in an anaerobic one-compartment in vitro PK/PD model over 72 h with a starting inoculum of ?8 log10 CFU/ml. Bactericidal activity was defined as a reduction of ?3 log10 CFU/ml from the starting inoculum. Both CPA and ERT were bactericidal against all four strains. CPA demonstrated improved activity against Bacteroides strains compared to that of ERT but had similar activity against Finegoldia magna and P. bivia, although modest regrowth was observed with CPA against P. bivia. No resistance emerged from any of the models. The pharmacokinetics achieved were 92 to 105% of the targets. CPA has potent in vitro activity against common anaerobic pathogens at clinically relevant drug exposures and may be a suitable single product for the management of complicated polymicrobial infections. PMID:24217692

Werth, Brian J.

2014-01-01

242

Bone and joint infections due to anaerobic bacteria: an analysis of 61 cases and review of the literature.  

PubMed

The diagnosis of anaerobic bone and joint infections (BJI) were underestimated before the advent of molecular identification and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). We report 61 cases of anaerobic infections based on our 4-year experience with the management of BJI. A total of 75% of cases were post-surgical infections, associated with osteosynthesis devices (65%). Early infections occurred in 27% of cases, delayed infections in 17.5% of cases, and late infections in 55% of cases. We recorded 36 species of 93 anaerobic strains using MALDI-TOF MS (91) and molecular methods (2). We identified 20 strains of Propionibacterium acnes, 13 of Finegoldia magna, six of Peptoniphilus asaccharolyticus, and six of P. harei. Polymicrobial infections occurred in 50 cases. Surgical treatment was performed in 93.5% of cases. The antibiotic treatments included amoxicillin (30%), amoxicillin-clavulanic acid (16%), metronidazole (30%), and clindamycin (26%). Hyperbaric oxygen therapy was used in 17 cases (28%). The relapse rate (27%) was associated with lower limbs localization (p?=?0.001). P. acnes BJI was associated with shoulder (p?=?0.019), vertebra (p?=?0.021), and head flap localization (p?=?0.011), and none of these cases relapsed (p?=?0.007). F. magna BJI was associated with ankle localization (p?=?0.014). Anaerobic BJI is typically considered as a post-surgical polymicrobial infection, and the management of this infection combines surgical and medical treatments. MALDI-TOF MS and molecular identification have improved diagnosis. Thus, physicians should be aware of the polymicrobial nature of anaerobic BJI to establish immediate broad-spectrum antibiotic treatment during the post-surgical period until accurate microbiological results have been obtained. PMID:24577953

Walter, G; Vernier, M; Pinelli, P O; Million, M; Coulange, M; Seng, P; Stein, A

2014-08-01

243

A newly designed degenerate PCR primer based on pmoA gene for detection of nitrite-dependent anaerobic methane-oxidizing bacteria from different ecological niches.  

PubMed

A new pmoA gene-based PCR primer set was designed for detection of nitrite-dependent anaerobic oxidation of methane (n-damo) bacteria from four different ecosystems, namely rice paddy soil, freshwater reservoir, reed bed, and sludge from wastewater treatment plant. This primer set showed high specificity and efficiency in recovering n-damo bacteria from these diverse samples. The obtained sequences showed 88-94 and 90-96% similarity to nucleotide and amino acid sequences, respectively, with the known NC10 phylum bacterium. According to the UniFrac principal coordinates analysis (PCoA), DNA sequences retrieved by the new PCR primer set in this study formed a separate group from the reported sequences, indicating higher diversity of n-damo in the environment. This newly designed PCR primer is capable of amplifying not only the currently known n-damo bacteria but also those that have not been reported, providing new information on the ecological diversity and distribution of this group of microorganisms in the ecosystem. PMID:24201910

Han, Ping; Gu, Ji-Dong

2013-12-01

244

Influence of decontamination on induction of arthritis in Lewis rats by cell wall fragments of Eubacterium aerofaciens. Arthropathic properties of indigenous anaerobic bacteria.  

PubMed Central

Although the cause (or causes) of rheumatoid arthritis is unknown, many workers have suggested that microorganisms play a part. The intestinal flora in particular has been related to the development of joint inflammation. It has been shown previously that cell wall fragments of several anaerobic Gram positive intestinal bacteria of human origin are arthritogenic after a single intraperitoneal injection in Lewis rats. The part played by indigenous microflora in this model has now been studied by decontaminating Lewis rats before the injection of Eubacterium aerofaciens cell wall fragments. The pattern and severity of arthritis appeared to be comparable in decontaminated and control rats. The second goal of this work was to isolate arthritogenic bacteria from the autochthonous intestinal flora of rats. Only a limited number of bacteria showing a resemblance to arthritogenic strains from human intestinal flora (i.e. E aerofaciens and Bifidobacterium adolescentis) could be isolated. These strains did not induce chronic arthritis after intraperitoneal injection. This may explain why spontaneous arthritis did not develop in Lewis rats. Images PMID:1586251

Kool, J; Severijnen, A J; Klasen, I S; Gerrits-Boeye, M Y; Hazenberg, M P

1992-01-01

245

Histamine-producing bacteria in decomposing skipjack tuna (Katsuwonus pelamis).  

PubMed

Spoilage in skipjack tuna (Katsuwonus pelamis) was studied under controlled conditions by incubating whole, fresh fish in seawater at 38 degrees C, the optimum temperature for histamine formation. Bacterial isolates were obtained from the loin tissue of a decomposing tuna containing 134 mg of histamine per 100 g and a total anaerobic count of 3.5 x 10(5)/g after incubation for 24 h. Over 92% of the 134 isolates obtained were facultatively or obligately anaerobic bacteria. Eighteen isolates produced histamine in culture media containing histidine, and these were identified as Clostridium perfringens, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, and Vibrio alginolyticus. Histidine decarboxylase activity of several isolates was measured in a tuna broth medium and with resting cells suspended in a buffered histidine solution. PMID:6289747

Yoshinaga, D H; Frank, H A

1982-08-01

246

Comparative in vitro activities of LFF571 against Clostridium difficile and 630 other intestinal strains of aerobic and anaerobic bacteria.  

PubMed

The in vitro activities of LFF571, a novel analog of GE2270A that inhibits bacterial growth by binding with high affinity for protein synthesis elongation factor Tu, fidaxomicin, and 10 other antimicrobial agents were determined against 50 strains of Clostridium difficile and 630 other anaerobic and aerobic organisms of intestinal origin. LFF571 possesses potent activity against C. difficile and most other Gram-positive anaerobes (MIC(90), ? 0.25 ?g/ml), with the exception of bifidobacteria and lactobacilli. The MIC(90)s for aerobes, including enterococci, Staphylococcus aureus (as well as methicillin-resistant S. aureus [MRSA] isolates), Streptococcus pyogenes, and other streptococci were 0.06, 0.125, 2, and 8 ?g/ml, respectively. Comparatively, fidaxomicin showed variable activity against Gram-positive organisms: MIC(90)s against C. difficile, Clostridium perfringens, and Bifidobacterium spp. were 0.5, ? 0.015, and 0.125 ?g/ml, respectively, but >32 ?g/ml against Clostridium ramosum and Clostridium innocuum. MIC(90) for S. pyogenes and other streptococci was 16 and >32 ?g/ml, respectively. LFF571 and fidaxomicin were generally less active against Gram-negative anaerobes. PMID:22290948

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

2012-05-01

247

Indigenous cellulolytic and hemicellulolytic bacteria enhanced rapid co-composting of lignocellulose oil palm empty fruit bunch with palm oil mill effluent anaerobic sludge.  

PubMed

The composting of lignocellulosic oil palm empty fruit bunch (OPEFB) with continuous addition of palm oil mill (POME) anaerobic sludge which contained nutrients and indigenous microbes was studied. In comparison to the conventional OPEFB composting which took 60-90 days, the rapid composting in this study can be completed in 40 days with final C/N ratio of 12.4 and nitrogen (2.5%), phosphorus (1.4%), and potassium (2.8%), respectively. Twenty-seven cellulolytic bacterial strains of which 23 strains were closely related to Bacillus subtilis, Bacillus firmus, Thermobifida fusca, Thermomonospora spp., Cellulomonas sp., Ureibacillus thermosphaericus, Paenibacillus barengoltzii, Paenibacillus campinasensis, Geobacillus thermodenitrificans, Pseudoxanthomonas byssovorax which were known as lignocellulose degrading bacteria and commonly involved in lignocellulose degradation. Four isolated strains related to Exiguobacterium acetylicum and Rhizobium sp., with cellulolytic and hemicellulolytic activities. The rapid composting period achieved in this study can thus be attributed to the naturally occurring cellulolytic and hemicellulolytic strains identified. PMID:24012093

Zainudin, Mohd Huzairi Mohd; Hassan, Mohd Ali; Tokura, Mitsunori; Shirai, Yoshihito

2013-11-01

248

Degradative capacities and 16S rRNA-targeted whole-cell hybridization of sulfate-reducing bacteria in an anaerobic enrichment culture utilizing alkylbenzenes from crude oil.  

PubMed Central

A mesophilic sulfate-reducing enrichment culture growing anaerobically on crude oil was used as a model system to study which nutritional types of sulfate-reducing bacteria may develop on original petroleum constituents in oil wells, tanks, and pipelines. Chemical analysis of oil hydrocarbons during growth revealed depletion of toluene and o-xylene within 1 month and of m-xylene, o-ethyltoluene, m-ethyltoluene, m-propyltoluene, and m-isopropyltoluene within approximately 2 months. In anaerobic counting series, the highest numbers of CFU (6 x 10(6) to 8 x 10(6) CFU ml-1) were obtained with toluene and benzoate. Almost the same numbers were obtained with lactate, a substrate often used for detection of the vibrio-shaped, incompletely oxidizing Desulfovibrio sp. In the present study, however, lactate yielded mostly colonies of oval to rod-shaped, completely oxidizing, sulfate-reducing bacteria which were able to grow slowly on toluene or crude oil. Desulfovibrio species were detected only at low numbers (3 x 10(5) CFU ml-1). In agreement with this finding, a fluorescently labeled, 16S rRNA-targeted oligonucleotide probe described in the literature as specific for members of the Desulfovibrionaceae (suggested family) hybridized only with a small portion (< 5%) of the cells in the enrichment culture. These results are consistent with the observation that known Desulfovibrio species do not utilize aromatic hydrocarbons, the predominant substrates in the enrichment culture. All known sulfate-reducing bacteria which utilize aromatic compounds belong to a separate branch, the Desulfobacteriaceae (suggested family). Most members of this family are complete oxidizers. For specific hybridization with members of this branch, the probe had to be modified by a nucleotide exchange. Indeed, this modified probe hybridized with more than 95% of the cells in the enrichment culture. The results show that completely oxidizing, alkylbenzene-utilizing sulfate-reducing bacteria rather than Desulfovibrio species have to be considered in attempts to understand the microbiology of sulfide production in oil wells, tanks, and pipelines when no electron donors other than the indigenous oil constituents are available. PMID:8837415

Rabus, R; Fukui, M; Wilkes, H; Widdle, F

1996-01-01

249

REDUCTION AND IMMOBILIZATION OF RADIONUCLIDES AND TOXIC METAL IONS USING COMBINED ZERO VALENT IRON AND ANAEROBIC BACTERIA  

EPA Science Inventory

Large groundwater plumes contaminated with toxic metal ions, including radionuclides, exist at several DOE facilities. Previous research indicated that both zero valent iron and sulfate reducing bacteria can yield significant decreases in concentrations of redox sensitive metals ...

250

In Vitro Activities of Ramoplanin, Teicoplanin, Vancomycin, Linezolid, Bacitracin, and Four Other Antimicrobials against Intestinal Anaerobic Bacteria  

PubMed Central

By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at ?2 ?g/ml against 287 of 300 (95.7%) gram-positive organisms, including 18 strains of Clostridium difficile for which MICs of ramoplanin were 0.25 to 0.5 ?g/ml; for 3 of these, linezolid MICs were 8 to 16 ?g/ml. Nineteen Clostridium innocuum strains for which the vancomycin MIC at which 90% of strains were inhibited was 16 ?g/ml were susceptible to ramoplanin at 0.06 to 0.25 ?g/ml and to teicoplanin at 0.125 to 1.0 ?g/ml. All strains of Eubacterium, Actinomyces, Propionibacterium, and Peptostreptococcus spp. were inhibited by ?0.25 ?g of ramoplanin per ml and ?1 ?g of vancomycin per ml. Ramoplanin was also active at ?4 ?g/ml against 15 of 22 of the Prevotella and Porphyromonas strains tested, but ramoplanin MICs for all 31 strains of the Bacteroides fragilis group, the Fusobacterium mortiferum-Fusobacterium varium group, and Veillonella spp. were ?256 ?g/ml. Ramoplanin displays excellent activity against C. difficile and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora. PMID:12821492

Citron, D. M.; Merriam, C. V.; Tyrrell, K. L.; Warren, Y. A.; Fernandez, H.; Goldstein, E. J. C.

2003-01-01

251

Properties of Desulfovibrio carbinolicus sp. nov. and Other Sulfate-Reducing Bacteria Isolated from an Anaerobic-Purification Plant  

PubMed Central

Several sulfate-reducing microorganisms were isolated from an anaerobic-purification plant. Four strains were classified as Desulfovibrio desulfuricans, Desulfovibrio sapovorans, Desulfobulbus propionicus, and Desulfovibrio sp. The D. sapovorans strain contained poly-?-hydroxybutyrate granules and seemed to form extracellular vesicles. A fifth isolate, Desulfovibrio sp. strain EDK82, was a gram-negative, non-spore-forming, nonmotile, curved organism. It was able to oxidize several substrates, including methanol. Sulfate, sulfite, thiosulfate, and sulfur were utilized as electron acceptors. Pyruvate, fumarate, malate, and glycerol could be fermented. Because strain EDK82 could not be ascribed to any of the existing species, a new species, Desulfovibrio carbinolicus, is proposed. The doubling times of the isolates were determined on several substrates. Molecular hydrogen, lactate, propionate, and ethanol yielded the shortest doubling times (3.0 to 6.3 h). Due to the presence of support material in an anaerobic filter system, these species were able to convert sulfate to sulfide very effectively at a hydraulic retention time as short as 0.5 h. Images PMID:16347324

Nanninga, Henk J.; Gottschal, Jan C.

1987-01-01

252

Viable Bacteria Associated with Red Blood Cells and Plasma in Freshly Drawn Blood Donations  

PubMed Central

Objectives Infection remains a leading cause of post-transfusion mortality and morbidity. Bacterial contamination is, however, detected in less than 0.1% of blood units tested. The aim of the study was to identify viable bacteria in standard blood-pack units, with particular focus on bacteria from the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC)-fraction. Design Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA) or blue lactose plates. For identification colony PCR was performed using primers targeting 16S rDNA. Setting Blood donors attending Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Hvidovre, Denmark, October 29th to December 10th 2013. Participants 60 donors (?50 years old), self-reported medically healthy. Results Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35%) of 60 RBC-fractions and in 32 (53%) of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10-6, respectively). Propionibacterium acnes was found in 23% of the donations, and Staphylococcus epidermidis in 38%. The majority of bacteria identified in the present study were either facultative anaerobic (59.5%) or anaerobic (27.8%) species, which are not likely to be detected during current routine screening. Conclusions Viable bacteria are present in blood from donors self-reported as medically healthy, indicating that conventional test systems employed by blood banks insufficiently detect bacteria in plasma. Further investigation is needed to determine whether routine testing for anaerobic bacteria and testing of RBC-fractions for adherent bacteria should be recommended. PMID:25751254

Damgaard, Christian; Magnussen, Karin; Enevold, Christian; Nilsson, Martin; Tolker-Nielsen, Tim; Holmstrup, Palle; Nielsen, Claus Henrik

2015-01-01

253

Digestion of Herring by Indigenous Bacteria in the Minke Whale Forestomach  

PubMed Central

Northeastern Atlantic minke whales (Balaenoptera acutorostrata) have a multichambered stomach system which includes a nonglandular forestomach resembling that of ruminants. Bacteria from the forestomachs of herring-eating whales were enumerated and isolated in an anaerobic rumen-like culture medium (M8W medium). The total viable population of anaerobic bacteria ranged from 73 × 107 to 145 × 108/ml of forestomach fluid (n = 4). Lactobacillus spp. (19.7%), Streptococcus spp. (35.9%), and Ruminococcus spp. (12.8%) were the most common of the bacterial strains (n = 117) isolated by use of M8W medium from the forestomach fluid population of two minke whales. Most of the isolates stained gram positive (93.2%), 62.4% were cocci, and all strains were strictly anaerobic. The population of lipolytic bacteria in one animal, enumerated by use of a selective lipid medium, constituted 89.7% of the viable population. The total viable population of anaerobic bacteria in freshly caught and homogenized herring (Clupea harengus) ranged from 56.7 to 95.0 cells per gram of homogenized prey (n = 3) when M8W medium was used. Pediococcus spp. (30.6%) and Aerococcus spp. (25.0%) were most common of the bacterial strains (n = 72) isolated from the homogenized herring. Most of the bacterial strains were gram positive (80.6%), and 70.8% were cocci. Unlike the forestomach bacterial population, as many as 61.1% of the strains from the herring were facultatively anaerobic. All bacterial strains isolated from the prey had phenotypic patterns different from those of strains isolated from the dominant bacterial population in the forestomach, indicating that the forestomach microbiota is indigenous. Scanning electron microscopic examinations revealed large numbers of bacteria, surrounded by a glycocalyx, attached to partly digested food particles in the forestomach. These data support the hypothesis that symbiotic microbial digestion occurs in the forestomach and that the bacteria are indigenous to minke whales. Images PMID:16349460

Olsen, Monica A.; Aagnes, Tove H.; Mathiesen, Svein D.

1994-01-01

254

Diverse anaerobic Cr(VI) tolerant bacteria from Cr(VI)-contaminated 100H site at Hanford  

NASA Astrophysics Data System (ADS)

Hexavalent Chromium [Cr(VI)] is a widespread contaminant found in soil, sediment, and ground water. Cr(VI) is more soluble, toxic, carcinogenic, and mutagenic compared to its reduced form Cr(III). In order to stimulate microbially mediated reduction of Cr(VI), a poly-lactate compound HRC was injected into the chromium contaminated aquifers at site 100H at Hanford. Based on the results of the bacterial community composition using high-density DNA microarray analysis of 16S rRNA gene products, we recently investigated the diversity of the dominant anaerobic culturable microbial population present at this site and their role in Cr(VI) reduction. Positive enrichments set up at 30°C using specific defined anaerobic media resulted in the isolation of an iron reducing isolate strain HAF, a sulfate reducing isolate strain HBLS and a nitrate reducing isolate, strain HLN among several others. Preliminary 16S rDNA sequence analysis identifies strain HAF as Geobacter metallireducens, strain HLN as Pseudomonas stutzeri and strain HBLS as a member of Desulfovibrio species. Strain HAF isolated with acetate as the electron donor utilized propionate, glycerol and pyruvate as alternative carbon sources, and reduced metals like Mn(IV) and Cr(VI). Growth was optimal at 37°C, pH of 6.5 and 0% salinity. Strain HLN isolated with lactate as electron donor utilized acetate, glycerol and pyruvate as alternative carbon sources, and reduced metals like Mn(IV) and Cr(VI). Optimal growth was observed at 37°C, at a pH of 7.5 and 0.3% salinity. Anaerobic active washed cell suspension of strain HLN reduced almost 95 micromolar Cr(VI) within 4 hours relative to controls. Further, with 100 micromolar Cr(VI) as the sole electron acceptor, cells of strain HLN grew to cell numbers of 4.05X 107/ml over a period of 24hrs after an initial lag, demonstrating direct enzymatic Cr(VI) reduction by this species. 10mM lactate served as the sole electron donor. These results demonstrate that Cr(VI) immobilization at the Hanford 100H site could be mediated by direct microbial metabolism apart from indirect chemical reduction of Cr(VI) by end products of microbial activity.

Chakraborty, R.; Phan, R.; Lam, S.; Leung, C.; Brodie, E. L.; Hazen, T. C.

2007-12-01

255

Isolation and characterization of a Klebsiella oxytoca strain for simultaneous azo-dye anaerobic reduction and bio-hydrogen production.  

PubMed

A facultative anaerobic bacteria strain GS-4-08, isolated from an anaerobic sequence batch reactor for synthetic dye wastewater treatment, was investigated for azo-dye decolorization. This bacterium was identified as a member of Klebsiella oxytoca based on Gram staining, morphology characterization and 16S rRNA gene analysis. It exhibited a good capacity of simultaneous decolorization and hydrogen production in the presence of electron donor. The hydrogen production was less affected even at a high Methyl Orange (MO) concentration of 0.5 mM, indicating a superior tolerability of this strain to MO. This efficient bio-hydrogen production from electron donor can not only avoid bacterial inhibition due to accumulation of volatile fatty acids during MO decolorization, but also can recover considerable energy from dye wastewater. PMID:22086069

Yu, Lei; Li, Wen-Wei; Lam, Michael Hon-Wah; Yu, Han-Qing; Wu, Chao

2012-07-01

256

Reduction and immobilization of radionuclides and toxic metal ions using combined zero valent iron and anaerobic bacteria. 1998 annual progress report  

SciTech Connect

'Previous research findings indicate that both zero valent iron and sulfate reducing bacteria (SRB) can yield significant decreases in Cr(VI) or U(VI) concentrations due to abiotic and microbial reduction, respectively. The major hypothesis associated with this research project is that a combined abiotic-biological system can synergistically combine both processes to maximize metal ion reduction in an engineered permeable reactive barrier. The overall goal of this project is to design a combined abiotic/microbial, reactive, permeable, in-situ barrier with sufficient reductive potential to prevent downgradient migration of toxic metal ions. The field-scale application of this technology would utilize anaerobic digester sludge, Fe(O) particles for supporting anaerobic biofilms, and suitable aquifer material for construction of the barrier. Successful completion of this goal requires testing of the two hypotheses listed above by evaluating: (1) the rates of abiotic metal ion reduction, and (2) the rates of microbial metal ion reduction in microbial and combined abiotic/microbial reduction systems under a range of environmental conditions. This report summarizes work after one and one-half years of a three year project. Abiotic studies: The thrust of the abiotic research conducted to date has been to determine the rates of Cr(VI) reduction in batch reactors and to evaluate the role of aquifer materials on those rates. Experiments have been conducted to determine the rates of reduction by Fe(II) and Fe(O). The parameters that have been evaluated are the effect of pH and the presence of sulfide and aquifer material.'

Weathers, L.

1998-06-01

257

Biocalalyst effects of immobilized anthraquinone on the anaerobic reduction of azo dyes by the salt-tolerant bacteria  

Microsoft Academic Search

The accelerating effect of dissolved redox mediators has been studied in details in the bio-decolorization processes, but there are little literatures about the non-dissolved redox mediators. Here we describe the accelerating effect of anthraquinone as a redox mediator in the bio-decolorization. Decolorization of azo dyes was carried out experimentally using the salt-tolerant bacteria under immobilized anthraquinone and high salt conditions.

Jianbo Guo; Jiti Zhou; Dong Wang; Cunping Tian; Ping Wang; M. Salah Uddin; Hui Yu

2007-01-01

258

Commensal anaerobic gut bacteria attenuate inflammation by regulating nuclear-cytoplasmic shuttling of PPAR-? and RelA  

Microsoft Academic Search

The human gut microflora is important in regulating host inflammatory responses and in maintaining immune homeostasis. The cellular and molecular bases of these actions are unknown. Here we describe a unique anti-inflammatory mechanism, activated by nonpathogenic bacteria, that selectively antagonizes transcription factor NF-?B. Bacteroides thetaiotaomicron targets transcriptionally active NF-?B subunit RelA, enhancing its nuclear export through a mechanism independent of

Jamie I Campbell; Timothy P King; George Grant; Emmelie A Jansson; Alistair G P Coutts; Sven Pettersson; Shaun Conway; Denise Kelly

2003-01-01

259

In Vitro Activity of Biapenem plus RPX7009, a Carbapenem Combined with a Serine ?-Lactamase Inhibitor, against Anaerobic Bacteria  

PubMed Central

Biapenem is a carbapenem being developed in combination with RPX7009, a new inhibitor of serine ?-lactamases. Biapenem was tested alone and in combination with fixed concentrations of RPX7009 by agar dilution against 377 recent isolates of anaerobes. A separate panel of 27 isolates of Bacteroides spp. with decreased susceptibility or resistance to imipenem was also tested. Comparator drugs included meropenem, piperacillin-tazobactam, ampicillin-sulbactam, cefoxitin, ceftazidime, metronidazole, clindamycin, and tigecycline plus imipenem, doripenem, and ertapenem for the 27 selected strains. For recent consecutive strains of Bacteroides species, the MIC90 for biapenem-RPX7009 was 1 ?g/ml, with a MIC90 of 4 ?g/ml for meropenem. Other Bacteroides fragilis group species showed a MIC90 of 0.5 ?g/ml for both agents. The MIC90s for biapenem-RPX7009 were 0.25 ?g/ml for Prevotella spp., 0.125 ?g/ml for Fusobacterium nucleatum and Fusobacterium necrophorum, 2 ?g/ml for Fusobacterium mortiferum, 0.5 ?g/ml for Fusobacterium varium, ?0.5 ?g/ml for Gram-positive cocci and rods, and 0.03 to 8 ?g/ml for clostridia. Against 5 B. fragilis strains harboring a known metallo-beta-lactamase, biapenem-RPX7009 MICs were comparable to those of other carbapenems (?32 ?g/ml). Against Bacteroides strains with an imipenem MIC of 2 ?g/ml, biapenem-RPX7009 had MICs of 0.5 to 2 ?g/ml, with MICs of 0.5 to 32 ?g/ml for meropenem, doripenem, and ertapenem. For strains with an imipenem MIC of 4 ?g/ml, the MICs for biapenem-RPX7009 were 4 to 16 ?g/ml, with MICs of 8 to >32 ?g/ml for meropenem, doripenem, and ertapenem. The inhibitor RPX7009 had no antimicrobial activity when tested alone, and it showed little or no potentiation of biapenem versus anaerobes. Biapenem-RPX7009 showed activity comparable to that of imipenem and was superior to meropenem, doripenem, and ertapenem against imipenem-nonsusceptible Bacteroides spp. PMID:23529731

Citron, Diane M.; Tyrrell, Kerin L.; Merriam, C. Vreni

2013-01-01

260

Host-Bacteria Crosstalk at the Dentogingival Junction  

PubMed Central

The dentogingival junction is of crucial importance in periodontal host defense both structurally and functionally. Oral bacteria exert a constant challenge to the host cells and tissues at the dentogingival junction. The host response is set up to eliminate the pathogens by the innate and adaptive defense mechanisms. In health, the commensal bacteria and the host defense mechanisms are in a dynamic steady state. During periodontal disease progression, the dental bacterial plaque, junctional epithelium (JE), inflammatory cells, connective tissue, and bone all go through a series of changes. The tissue homeostasis is turned into tissue destruction and progression of periodontitis. The classical study of Slots showed that in the bacterial plaque, the most remarkable change is the shift from gram-positive aerobic and facultatively anaerobic flora to a predominantly gram-negative and anaerobic flora. This has been later confirmed by several other studies. Furthermore, not only the shift of the bacterial flora to a more pathogenic one, but also bacterial growth as a biofilm on the tooth surface, allows the bacteria to communicate with each other and exert their virulence aimed at favoring their growth. This paper focuses on host-bacteria crosstalk at the dentogingival junction and the models studying it in vitro. PMID:22899931

Pöllänen, M. T.; Laine, M. A.; Ihalin, R.; Uitto, V.-J.

2012-01-01

261

Oral Gram-negative anaerobic bacilli as a reservoir of ?-lactam resistance genes facilitating infections with multiresistant bacteria.  

PubMed

Many ?-lactamases have been described in various Gram-negative bacilli (Capnocytophaga, Prevotella, Fusobacterium, etc.) of the oral cavity, belonging to class A of the Ambler classification (CepA, CblA, CfxA, CSP-1 and TEM), class B (CfiA) or class D in Fusobacterium nucleatum (FUS-1). The minimum inhibitory concentrations of ?-lactams are variable and this variation is often related to the presence of plasmids or other mobile genetic elements (MGEs) that modulate the expression of resistance genes. DNA persistence and bacterial promiscuity in oral biofilms also contribute to genetic transformation and conjugation in this particular microcosm. Overexpression of efflux pumps is facilitated because the encoding genes are located on MGEs, in some multidrug-resistant clinical isolates, similar to conjugative transposons harbouring genes encoding ?-lactamases. All these facts lead us to consider the oral cavity as an important reservoir of ?-lactam resistance genes and a privileged place for genetic exchange, especially in commensal strictly anaerobic Gram-negative bacilli. PMID:25465519

Dupin, Clarisse; Tamanai-Shacoori, Zohreh; Ehrmann, Elodie; Dupont, Anais; Barloy-Hubler, Frédérique; Bousarghin, Latifa; Bonnaure-Mallet, Martine; Jolivet-Gougeon, Anne

2015-02-01

262

Evaluation of the use of PCR and reverse transcriptase PCR for detection of pathogenic bacteria in biosolids from anaerobic digestors and aerobic composters.  

PubMed

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 purification of DNA or RNA before PCR or RT-PCR amplification. To test the reproducibility and reliability of the newly developed methods, 46 unseeded samples were collected from diverse aerobic (composting) facilities and anaerobic digestors and analyzed by both culture-based classical and newly developed PCR-based procedures. No false-positive but some false-negative results were generated by the PCR- or RT-PCR-based methods after one-step enrichment when compared to the classical detection methods. The results indicated that the level of activity of the tested bacteria in unseeded samples was very low compared to that of freshly inoculated cells, preventing samples from reaching the cell density required for PCR-based detection after one-step enrichment. However, for Salmonella spp., a distinct PCR product could be obtained for all 22 nonamended samples that tested positive for Salmonella spp. by the classical detection procedure when a selective two-step enrichment (20 h in peptone water at 37 degrees C and 24 h in Rappaport Vassiliadis medium at 43 degrees C) was performed prior to nucleic acid extraction and PCR. Hence, the classical procedure was shortened, since cell plating and further differentiation of isolated colonies can be omitted, substituted for by highly sensitive and reliable detection based on nucleic acid extraction and PCR. Similarly, 2 of the 22 samples in which Salmonella spp. were detected also tested positive for Listeria monocytogenes according to a two-step enrichment procedure followed by PCR, compared to 3 samples that tested positive when classical isolation procedures were followed. The study shows that selective two-step enrichment is useful when very low numbers of bacterial pathogens must be detected in organic waste materials, such as biosolids. There were no false-positive results derived from DNA of dead cells in the waste sample, suggesting that it is not necessary to perform RT-PCR analyses when PCR is combined with selective enrichment. Large numbers of added nontarget bacteria did not affect detection of Salmonella spp., L. monocytogenes, and Y. enterocolitica but increased the detection limit of Staphylococcus aureus from <10 to 10(4) CFU/g of organic waste. Overall, the detection methods developed using seeded organic waste samples from one waste treatment facility (WTF) needed to be modified for satisfactory detection of pathogens in samples from other WTFs, emphasizing the need for extensive field testing of laboratory-derived PCR protocols. A survey of 13 WTFs in Germany revealed that all facilities complied with the German Biowaste Ordinance, which mandates that the end product after anaerobic digestion or aerobic composting be free of Salmonella In addition, all biosolids were free of L. monocytogenes, Staphylococcus aureus, and Y. enterocolitica, as evidenced by both classical and PCR-based detection methods. PMID:12902250

Burtscher, Carola; Wuertz, Stefan

2003-08-01

263

Mono- and Dialkyl Glycerol Ether Lipids in Anaerobic Bacteria: Biosynthetic Insights from the Mesophilic Sulfate Reducer Desulfatibacillum alkenivorans PF2803T.  

PubMed

Bacterial glycerol ether lipids (alkylglycerols) have received increasing attention during the last decades, notably due to their potential role in cell resistance or adaptation to adverse environmental conditions. Major uncertainties remain, however, regarding the origin, biosynthesis, and modes of formation of these uncommon bacterial lipids. We report here the preponderance of monoalkyl- and dialkylglycerols (1-O-alkyl-, 2-O-alkyl-, and 1,2-O-dialkylglycerols) among the hydrolyzed lipids of the marine mesophilic sulfate-reducing proteobacterium Desulfatibacillum alkenivorans PF2803(T) grown on n-alkenes (pentadec-1-ene or hexadec-1-ene) as the sole carbon and energy source. Alkylglycerols account for one-third to two-thirds of the total cellular lipids (alkylglycerols plus acylglycerols), depending on the growth substrate, with dialkylglycerols contributing to one-fifth to two-fifths of the total ether lipids. The carbon chain distribution of the lipids of D. alkenivorans also depends on that of the substrate, but the chain length and methyl-branching patterns of fatty acids and monoalkyl- and dialkylglycerols are systematically congruent, supporting the idea of a biosynthetic link between the three classes of compounds. Vinyl ethers (1-alken-1'-yl-glycerols, known as plasmalogens) are not detected among the lipids of strain PF2803(T). Cultures grown on different (per)deuterated n-alkene, n-alkanol, and n-fatty acid substrates further demonstrate that saturated alkylglycerols are not formed via the reduction of hypothetic alken-1'-yl intermediates. Our results support an unprecedented biosynthetic pathway to monoalkyl/monoacyl- and dialkylglycerols in anaerobic bacteria and suggest that n-alkyl compounds present in the environment can serve as the substrates for supplying the building blocks of ether phospholipids of heterotrophic bacteria. PMID:25724965

Grossi, Vincent; Mollex, Damien; Vinçon-Laugier, Arnauld; Hakil, Florence; Pacton, Muriel; Cravo-Laureau, Cristiana

2015-05-01

264

Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors  

USGS Publications Warehouse

Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable-Te-isotopic fractionation (isotopic enrichment factor [??] = -0.4 to -1.0 per ml per atomic mass unit) and results in the formation of unique crystalline Te(0) nanoarchitectures as end products. The Te(0) crystals occur internally within but mainly externally from the cells, and each microorganism forms a distinctly different structure. Those formed by Bacillus selenitireducens initially are nanorods (???10-nm diameter by 200-nm length), which cluster together, forming larger (???1,000-nm) rosettes composed of numerous individual shards (???100-nm width by 1,000-nm length). In contrast, Sulfurospirillium barnesii forms extremely small, irregularly shaped nanospheres (diameter < 50 nm) that coalesce into larger composite aggregates. Energy-dispersive X-ray spectroscopy and selected area electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

Baesman, S.M.; Bullen, T.D.; Dewald, J.; Zhang, Dongxiao; Curran, S.; Islam, F.S.; Beveridge, T.J.; Oremland, R.S.

2007-01-01

265

Formation of Tellurium Nanocrystals during Anaerobic Growth of Bacteria That Use Te Oxyanions as Respiratory Electron Acceptors?  

PubMed Central

Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable-Te-isotopic fractionation (isotopic enrichment factor [?] = ?0.4 to ?1.0 per ml per atomic mass unit) and results in the formation of unique crystalline Te(0) nanoarchitectures as end products. The Te(0) crystals occur internally within but mainly externally from the cells, and each microorganism forms a distinctly different structure. Those formed by Bacillus selenitireducens initially are nanorods (?10-nm diameter by 200-nm length), which cluster together, forming larger (?1,000-nm) rosettes composed of numerous individual shards (?100-nm width by 1,000-nm length). In contrast, Sulfurospirillum barnesii forms extremely small, irregularly shaped nanospheres (diameter < 50 nm) that coalesce into larger composite aggregates. Energy-dispersive X-ray spectroscopy and selected area electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. PMID:17277198

Baesman, Shaun M.; Bullen, Thomas D.; Dewald, James; Zhang, Donghui; Curran, Seamus; Islam, Farhana S.; Beveridge, Terry J.; Oremland, Ronald S.

2007-01-01

266

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

2010-06-01

267

Effect of ammonium nitrogen concentration on the ammonia-oxidizing bacteria community in a membrane bioreactor for the treatment of anaerobically digested swine wastewater.  

PubMed

A membrane bioreactor (MBR) was developed for the treatment of anaerobically digested swine wastewater and to investigate the effect of ammonium nitrogen concentration on biological nitrogen removal and ammonia-oxidizing bacteria (AOB) community structures. The MBR achieved a high NH4(+)-N removal efficiency of 0.08 kgNMLSS(-1)d(-1) and removed 95% of the influent NH4(+)-N. The TN removal rate was highest of 82.62% at COD/TN and BOD5/TN ratios of 8.76 ± 0.30 and 3.02 ± 0.09, respectively. With the decrease in ammonium nitrogen concentrations, the diversity of the AOB community declined and showed a simple pattern of DGGE. However, the AOB population size remained high, with abundance of 10(7)-10(9) copies mL(-1). With the decrease of ammonium nitrogen concentrations, Nitrosomonas eutropha gradually disappeared, whereas Nitrosomonas sp. OZK11 showed constant adaptability to survive during each treatment stage. The selective effect of ammonium concentration on AOB species could be due to the affinity for NH4(+)-N. In this study, the changes of ammonium nitrogen concentrations in digested swine wastewater were found to have selective effects on the composition of AOB community, and biological nitrogen removal was improved by optimising the influencing parameters. PMID:24680388

Sui, Qianwen; Liu, Chong; Dong, Hongmin; Zhu, Zhiping

2014-09-01

268

Growth of Facultatively Heterofermentative Lactobacilli on Starter Cell Suspensions  

PubMed Central

The growth of facultatively heterofermentative lactobacilli (FHL) on cell suspensions of the homofermentative Lactobacillus helveticus was investigated. Osmotic lysis of L. helveticus led to a significant increase of ribose. It decreased steadily in parallel with the growth of FHL, strongly suggesting that the bacteria used ribose as a growth substrate. PMID:10584024

Rapposch, S.; Eliskases-Lechner, F.; Ginzinger, W.

1999-01-01

269

Physiology, biochemistry, and genetics of a pure culture of an obligatory anaerobic bacterium that utilizes 2,4,-6-trinitrotoluene (TNT) and biodegradation of RDX by pure cultures of obligatory anaerobic bacteria of the genus clostridium. Final report, 1 September 1993-31 August 1996  

Microsoft Academic Search

In work supported by the US AFOSR (grant F49620-94-1-0306) we are conducting detailed biochemical and genetic studies of three strains of Clostridium bifernientans, obligatory anaerobic bacteria that appear to completely degrade a variety of nitroaromatic compounds, including 2,4,6-trinitrotoluene (TNT). We are determining the optimal physiological conditions for the degradative activities of C. bifermentans strains; and identifying and characterizing enzymes and

R. L. Crawford; D. L. Crawford

1996-01-01

270

ANALYSIS OF ANAEROBIC MICROORGANISMS METABOLITES  

Microsoft Academic Search

This paper presents an overwiew of anaerobic bacterias metabolites and their effects on Microbially Improved oil recovery (MIOR). Chemical analysis methods for coexisting gas-, water-, and oil phases of MIOR field tests or laboratory experiments are described for mixtures of potential metabolites of anaerobic microorganisms. The obtained data are compared with literature values. The metabolites in the gas- and oil

G. Jacobs; D. Severin

1997-01-01

271

Predatory prokaryotes: predation and primary consumption evolved in bacteria  

NASA Technical Reports Server (NTRS)

Two kinds of predatory bacteria have been observed and characterized by light and electron microscopy in samples from freshwater sulfurous lakes in northeastern Spain. The first bacterium, named Vampirococcus, is Gram-negative and ovoidal (0.6 micrometer wide). An anaerobic epibiont, it adheres to the surface of phototrophic bacteria (Chromatium spp.) by specific attachment structures and, as it grows and divides by fission, destroys its prey. An important in situ predatory role can be inferred for Vampirococcus from direct counts in natural samples. The second bacterium, named Daptobacter, is a Gram-negative, facultatively anaerobic straight rod (0.5 x 1.5 micrometers) with a single polar flagellum, which collides, penetrates, and grows inside the cytoplasm of its prey (several genera of Chromatiaceae). Considering also the well-known case of Bdellovibrio, a Gram-negative, aerobic curved rod that penetrates and divides in the periplasmic space of many chemotrophic Gram-negative bacteria, there are three types of predatory prokaryotes presently known (epibiotic, cytoplasmic, and periplasmic). Thus, we conclude that antagonistic relationships such as primary consumption, predation, and scavenging had already evolved in microbial ecosystems prior to the appearance of eukaryotes. Furthermore, because they represent methods by which prokaryotes can penetrate other prokaryotes in the absence of phagocytosis, these associations can be considered preadaptation for the origin of intracellular organelles.

Guerrero, R.; Pedros-Alio, C.; Esteve, I.; Mas, J.; Chase, D.; Margulis, L.

1986-01-01

272

Evolution of N-converting bacteria during the start-up of anaerobic digestion coupled biological nitrogen removal pilot-scale bioreactors treating high-strength animal waste slurry.  

PubMed

Animal wastes have been successfully employed in anaerobic biogas production, viewed as a pragmatic approach to rationalize energy costs in animal farms. Effluents resulting from that process however are still high in nitrogen such that attempts were made to couple biological nitrogen removal (BNR) with anaerobic digestion (AD). The demand for organic substrate in such system is partitioned between the anaerobic metabolism in AD and the heterotrophic denitrification cascade following the autotrophic nitrification in BNR. Investigation of underlying N-converting taxa with respect to process conditions is therefore critical in optimizing N-removal in such treatment system. In this study, a pilot-scale intermittently aerated BNR bioreactor was started up either independently or in series with the AD bioreactor to treat high-strength swine waste slurry. The compositions of NH(3)-oxidizing bacteria (AOB), NO(2)(-)-oxidizing bacteria (NOB) and denitrifiers (nosZ gene) were profiled by polymerase chain reaction-capillary electrophoresis/single strand conformation polymorphism (PCR-CE/SSCP) technique and clone library analysis. Performance data suggested that these two process configurations significantly differ in the modes of biological N-removal. PCR-CE/SSCP based profiling of the underlying nitrifying bacteria also revealed the selection of distinct taxa between process configurations. Under the investigated process conditions, correlation of performance data and composition of underlying nitrifiers suggest that the stand-alone BNR bioreactor tended to favor N-removal via NO(3)(-) whereas the coupled bioreactors could be optimized to achieve the same via a NO(2)(-) shortcut. PMID:19329298

Anceno, Alfredo J; Rouseau, Pierre; Béline, Fabrice; Shipin, Oleg V; Dabert, Patrick

2009-07-01

273

Anaerobic thermophiles.  

PubMed

The term "extremophile" was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of "extreme" environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally "hot environments" on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has definitely made this area of investigation more exciting. Particularly fascinating are their structural and physiological features allowing them to withstand extremely selective environmental conditions. These properties are often due to specific biomolecules (DNA, lipids, enzymes, osmolites, etc.) that have been studied for years as novel sources for biotechnological applications. In some cases (DNA-polymerase, thermostable enzymes), the search and applications successful exceeded preliminary expectations, but certainly further exploitations are still needed. PMID:25370030

Canganella, Francesco; Wiegel, Juergen

2014-01-01

274

Anaerobic Thermophiles  

PubMed Central

The term “extremophile” was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of “extreme” environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally “hot environments” on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has definitely made this area of investigation more exciting. Particularly fascinating are their structural and physiological features allowing them to withstand extremely selective environmental conditions. These properties are often due to specific biomolecules (DNA, lipids, enzymes, osmolites, etc.) that have been studied for years as novel sources for biotechnological applications. In some cases (DNA-polymerase, thermostable enzymes), the search and applications successful exceeded preliminary expectations, but certainly further exploitations are still needed. PMID:25370030

Canganella, Francesco; Wiegel, Juergen

2014-01-01

275

Reductive dehalogenation by anaerobic bacteria  

Microsoft Academic Search

The understanding of the fate of synthetic halogenated hydrocarbons became a matter of major interest over the last two decades. Halogenated compounds may threaten ecosystems due to their biocide properties. The degradability of halocompounds determines whether they will accumulate in a certain environment or whether they will be transformed to harmless products. A whole range of anthropogenic organohalogen compounds was

C. Holliger

1992-01-01

276

Could petroleum biodegradation be a joint achievement of aerobic and anaerobic microrganisms in deep sea reservoirs?  

PubMed Central

Several studies suggest that petroleum biodegradation can be achieved by either aerobic or anaerobic microorganisms, depending on oxygen input or other electron acceptors and appropriate nutrients. Evidence from in vitro experiments with samples of petroleum formation water and oils from Pampo Field indicate that petroleum biodegradation is more likely to be a joint achievement of both aerobic and anaerobic bacterial consortium, refining our previous observations of aerobic degradation. The aerobic consortium depleted, in decreasing order, hydrocarbons > hopanes > steranes > tricyclic terpanes while the anaerobic consortium depleted hydrocarbons > steranes > hopanes > tricyclic terpanes. The oxygen content of the mixed consortia was measured from time to time revealing alternating periods of microaerobicity (O2 ~0.8 mg.L-1) and of aerobicity (O2~6.0 mg.L-1). In this experiment, the petroleum biodegradation changed from time to time, alternating periods of biodegradation similar to the aerobic process and periods of biodegradation similar to the anaerobic process. The consortia showed preferences for metabolizing hydrocarbons > hopanes > steranes > tricyclic terpanes during a 90-day period, after which this trend changed and steranes were more biodegraded than hopanes. The analysis of aerobic oil degrading microbiota by the 16S rRNA gene clone library detected the presence of Bacillus, Brevibacterium, Mesorhizobium and Achromobacter, and the analysis of the anaerobic oil degrading microbiota using the same technique detected the presence of Bacillus and Acinetobacter (facultative strains). In the mixed consortia Stenotrophomonas, Brevibacterium, Bacillus, Rhizobium, Achromobacter and 5% uncultured bacteria were detected. This is certainly a new contribution to the study of reservoir biodegradation processes, combining two of the more important accepted hypotheses. PMID:22196374

2011-01-01

277

Characterization of Two New Facultative Methanotrophs  

PubMed Central

Two new facultative methane-oxidizing bacteria have been isolated from lake water enrichments. The organisms have been characterized in terms of colony types, growth characteristics, the guanine plus cytosine content of their deoxyribonucleic acid, thin sections, oxidation rates, and carbon assimilation pathways. Methane-grown cells of both organisms contained intracytoplasmic membranes similar to those described as type II in other methanotrophic bacteria. Neither organism had such membranes when grown heterotrophically. Both organisms assimilated methane by way of the isocitrate lyase-negative serine pathway for formaldehyde incorporation. The enzymes of this pathway were high in specific activity in cells grown on methane and were at low levels in cells grown either on heterotrophic substrates or on heterotrophic substrates plus methane. It is proposed that both organisms be classified in the genus Methylobacterium as two new species, Methylobacterium ethanolicum and Methylobacterium hypolimneticum. Images PMID:16345617

Lynch, Martha J.; Wopat, Ann E.; O'Connor, Mary L.

1980-01-01

278

Characterization of salt tolerant bacteria isolated from the rhizosphere of Leptochloa fusca and Atriplex rhogodoidaes.  

PubMed

Bacteria from the rhizosphere of Leptochloa fusca (Lf) and Atriplex rhogodoidaes (Ar) were isolated at 0.5 M NaCl Plates. Apparently 20 different purified colonies from each plant species were picked and streaked on 0.8 M salt concentration. The survivors were subsequently streaked on 1 M salt concentration. Only 4 from Lf and 3 from Ar could manage to grow at 1 M concentration. Slight variation was observed in colonial morphology of these strains. Except for Lf-5b all strains were Gram-negative rods. U-5b was Gram-positive and pleiomorphic. Lf-5b and Ar-5b, were non-motile, while rest of the isolates were motile. Catalase and oxidase enzymes were present in Lf-2a, Lf-4a and Ar-5b while Lf-4b was positive for oxidase only. All but Lf-2b and Ar-5b could ferment glucose and mannitol. Slight variation in the 20 biochemical characters of these isolates was observed. According to Bergey's classification these isolates fall in four groups. Lf-2b and Ar-Sb belong to Gram-negative aerobic rods; Lf-4a, Lf-4b and Ar-Sa to Gram-negative facultative anaerobic rods; Ar-3b to Gram-negative anaerobic rods; and Lf-Sb to Gram-positive anaerobic bacteria. PMID:16414647

Hasnain, S; Taskeen, N

1989-07-01

279

Establishment of facultative sexuals  

NASA Astrophysics Data System (ADS)

The existence of sex is one of the major unsolved problems in biology. We use computer simulations to model conditions in which sex may first become established. We develop an individual-based population model and show that a hypothetical facultative sex gene can fix, provided that the initial cost is low. It is demonstrated that the equilibrium fitness in the population increases with increasing population size and decreasing mutation rate. The probability of the establishment of the sex gene is found not to be directly related to the fitness difference between the asexual and sexual populations. This change in fitness on changing the parameters of the model is investigated.

Paley, Chris J.; Taraskin, Sergei N.; Elliott, Stephen R.

2007-06-01

280

Engineering an anaerobic metabolic regime in Pseudomonas putida KT2440 for the anoxic biodegradation of 1,3-dichloroprop-1-ene.  

PubMed

Pseudomonas putida KT2440, a microbial cell factory of reference for industrial whole-cell biocatalysis, is unable to support biochemical reactions that occur under anoxic conditions, limiting its utility for a large number of relevant biotransformations. Unlike (facultative) anaerobes, P. putida resorts to NADH oxidation via an oxic respiratory chain and completely lacks a true fermentation metabolism. Therefore, it cannot achieve the correct balances of energy and redox couples (i.e., ATP/ADP and NADH/NAD(+)) that are required to sustain an O(2)-free lifestyle. To overcome this state of affairs, the acetate kinase (ackA) gene of the facultative anaerobe Escherichia coli and the pyruvate decarboxylase (pdc) and alcohol dehydrogenase II (adhB) genes of the aerotolerant Zymomonas mobilis were knocked-in to a wild-type P. putida strain. Biochemical and genetic assays showed that conditional expression of the entire enzyme set allowed the engineered bacteria to adopt an anoxic regime that maintained considerable metabolic activity. The resulting strain was exploited as a host for the heterologous expression of a 1,3-dichloroprop-1-ene degradation pathway recruited from Pseudomonas pavonaceae 170, enabling the recombinants to degrade this recalcitrant chlorinated compound anoxically. These results underscore the value of P. putida as a versatile agent for biotransformations able to function at progressively lower redox statuses. PMID:23149123

Nikel, Pablo I; de Lorenzo, Víctor

2013-01-01

281

Bacteria associated with false-positive most-probable-number coliform test results for shellfish and estuaries.  

PubMed Central

Aerobic and facultatively anaerobic bacteria isolated from false-positive, presumptive, total coliform, most-probable-number tests of Chesapeake Bay oyster, water, and sediment samples were characterized and then classified by numerical taxonomy. A total of 538 bacterial strains clustered into 17 phena, the predominant groups of which were Enterobacteriaceae (including Escherichia coli), Aeromonas spp., and Bacillus spp. Bacillus spp. were recovered most frequently from sediment samples. Gas-producing strains which were not members of the Enterobacteriaceae were not isolated during this study. However, disproportionately large numbers of atypical and anaerogenic lactose-fermenting strains were encountered. We concluded that no single, specific bacterial group can be identified as being responsible for the false-positive reaction in the presumptive coliform test. Instead, the false-positive reaction is a result of complex interactions among various genera, representing predominantly bacteria other than coliforms. PMID:7013700

Hussong, D; Damaré, J M; Weiner, R M; Colwell, R R

1981-01-01

282

One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production. Progress report, June 1990--May 1992  

SciTech Connect

This reporting period, progress is reported on the following: metabolic pathway of solvent production in B. methylotrophicum; the biochemical mechanism for metabolic regulation of the succinate fermentation; models to understand the physiobiochemical function of formate metabolism in anaerobes and; models for understanding the influence of low pH on one carbon metabolism. (CBS)

Zeikus, J.G.; Jain, M.K.

1992-04-01

283

Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria  

Technology Transfer Automated Retrieval System (TEKTRAN)

The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effecti...

284

Oxygen regulated gene expression in Escherichia coli: control of anaerobic respiration by the FNR protein.  

PubMed

Molecular oxygen is an important regulatory signal in facultative anaerobic bacteria and controls the expression of a great variety of genes positively or negatively. The expression of anaerobic respiration and of related functions of E. coli is controlled by the positive gene regulator FNR, which activates transcription in the absence of O2. The regulated genes carry a FNR consensus sequence upstream of the promoter. Under the same conditions FNR represses some of the genes of aerobic respiration. The binding to the DNA occurs by an alpha-helix-turn-alpha-helix DNA-binding domain. FNR contains 5 cysteine residues, four of which are arranged in a cluster close to the N-terminal end. For the function of FNR as a O2-dependent regulator three of the cysteine residues in the cluster and the residue outside the cluster are essential. FNR binds iron as a cofactor which most likely is involved in the O2-sensing by the protein. The experiments indicate that the cysteine residues are responsible for the binding of the iron. From the protein in vivo two functional states can be differentiated, an aerobic or metal-depleted form and an anaerobic form. Only the anaerobic form acts as a gene activator or repressor. Sensing of O2 or of positive redox potentials by the iron ion is thought to cause the conversion of the two functional states. The FNR protein in addition contains a potential nucleotide binding domain. The significance and function of this site is not clear. PMID:1854188

Unden, G; Trageser, M

1991-02-01

285

Anaerobic Infections in Children with Neurological Impairments.  

ERIC Educational Resources Information Center

Children with neurological impairments are prone to develop serious infection with anaerobic bacteria. The most common anaerobic infections are decubitus ulcers; gastrostomy site wound infections; pulmonary infections (aspiration pneumonia, lung abscesses, and tracheitis); and chronic suppurative otitis media. The unique microbiology of each of…

Brook, Itzhak

1995-01-01

286

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

2013-07-01

287

INTRODUCTION: Intracellular pathogens, which include viruses and some bacteria,  

E-print Network

mechanisms to detect and disable pathogens. RATIONALE: We hypothesized that one method of pathogen detection, coxsackievirus, entero- virus, and the facultative cytosolic bacteria Salmonella--but not enveloped respiratory

Napp, Nils

288

Anaerobic oral and dental infection.  

PubMed

Anaerobes make up a significant part of the oral and dental indigenous and pathogenic flora. Their role in periodontal disease, root canal infections, infections of the hard and soft oral tissue, as well as their importance as foci for disseminated infectious disease is well established. Despite the ubiquitous involvement of bacteria, significant progress in our understanding of specific microbial etiologies has occurred only in the past decade. Estimates of the number of species recovered from samples of subgingival plaque range from 250 to 400, a large portion made up by anaerobes. Common anaerobic isolates include Fusobacterium, Bacteroides, Actinomyces, Peptococcus, Peptostreptococcus, Selenomonas, Eubacterium, Propionibacterium, and Treponema. Recently, several significant advances in our knowledge have set the stage for future research. First, circulating levels of hormones in pregnant women were shown to be stimulatory to Bacteroides species, which were associated with increased levels of gingival infection. Second, bacterial invasion of the soft and hard periodontal tissues has been documented in gingivitis, advanced periodontitis, and localized juvenile periodontitis. The frequency and identity of invading bacteria will determine the implications for diagnosis and treatment. Third, antibacterial "probes" aimed at anaerobic (and capnophilic) bacteria have had promising results in controlling and arresting oral, dental, and peridontal anaerobic infections. PMID:6372018

Newman, M G

1984-01-01

289

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

290

Growth of sulfate-reducing bacteria under acidic conditions in an upflow anaerobic bioreactor as a treatment system for acid mine drainage  

Microsoft Academic Search

The aim of this investigation was to develop a system for the remediation of acid mine drainage using sulphate-reducing bacteria. An upflow porous medium bioreactor was inoculated with sulphate-reducing bacteria (SRB) and operated under acidic conditions. The reactor was operated under continuous flow and was shown to be capable of sulfate reduction at pH 4.5, 4.0, 3.5 and 3.25 in

Phillip Elliott; Santo Ragusa; David Catcheside

1998-01-01

291

The capacity of hydrogenotrophic anaerobic bacteria to compete for traces of hydrogen depends on the redox potential of the terminal electron acceptor  

Microsoft Academic Search

The effect of different electron acceptors on substrate degradation was studied in pure and mixed cultures of various hydrogenotrophic homoacetogenic, methanogenic, sulfate-reducing, fumarate-reducing and nitrate-ammonifying bacteria. Two different species of these bacteria which during organic substrate degradation produce and consume hydrogen, were cocultured on a substrate which was utilized only by one of them. Hydrogen, which was excreted as intermediate

Ralf Cord-Ruwisch; Hans-Jiirgen Seitz; Ralf Conrad

1988-01-01

292

Diversity of anaerobic halophilic microorganisms  

NASA Astrophysics Data System (ADS)

Life in the presence of high salt concentrations is compatible with life in the absence of oxygen. Halophilic and halotolerant anaerobic prokaryotes are found both in the archaeal and in the bacterial domain, and they display a great metabolic diversity. Many of the representatives of the Halobacteriales (Archaea), which are generally considered aerobes, have the potential of anaerobic growth. Some can use alternative electron acceptors such as nitrate, fumarate, dimethylsulfoxide or trimethylamine-N-oxide Halobacterium salinarum can also grow fermentatively on L-arginine, and bacteriorhodopsin-containing cells may even grow anaerobically, energized by light. Obligatory anaerobic halophilic methanogenic Archaea also exist. The bacterial domain contains many anaerobic halophiles, including sulfate reducers. There is also a group of specialized obligatory anaerobic Bacteria, phylogenetically clustering in the low G + C branch of the Firmicutes. Most representatives of this group (order Haloanaerobiales, families Haloanaerobiaceae and Halobacteroidaceae) are fermentative, using a variety of carbohydrates and amino acids. One species combines the potential for anaerobic growth at high salt concentrations with a preference for high temperatures. Others are homoacetogens; Acetohalobium arabaticum can grow anaerobically as a chemolithotroph, producing acetate from hydrogen and CO2. The Haloanaerobiales accumulate high concentrations of K+ and Cl- in their cytoplasm, thereby showing a strategy of salt adaptation similar to that used by the Halobacteriales. Recently a new representative of the Haloanaerobiales was isolated from bottom sediments of the Dead Sea (strain DSSe1), which grows anaerobically by oxidation of glycerol to acetate and CO2 while reducing selenate to selenite and elementary selenium. Other electron acceptors supporting anaerobic growth of this strain are nitrate and trimethylamine-N-oxide. The versatility of life at high salt concentrations with respect to the variety of substrates used, the types of dissimilatory metabolism, and the diversity of potential electron acceptors has important implications for the potential for life in hostile environments lacking oxygen and high in salt, implications that may also be relevant to astrobiology.

Oren, Aharon; Oremland, Roland S.

2000-12-01

293

Bacteria Associated with the Gut Tract of Larval Stages of the Aquatic Cranefly Tipula abdominalis (Diptera; Tipulidae) †  

PubMed Central

Scanning electron microscopy, light microscopy, and direct isolations were used to examine the distribution and diversity of bacteria in the gut tracts of larval stages of Tipula abdominalis. The animal had an enlarged hindgut which housed a diverse bacterial community in the lumen and directly attached to the gut wall. Distinct localization was noted, with the most dense and most diverse community anterior to the rectum. A distinct architecture of bacteria occurred in this region, characterized by a layering or a “weblike” array of filamentous bacteria overlying mats of bacteria closely associated with the gut wall. Although morphological diversity was high in the hindgut, filamentous bacteria were the dominant morphology observed. The attached microbiota, sloughed during ecdysis, recolonized to the same density and diversity observed before the molt. The majority of the isolatable bacterial types were facultatively anaerobic. The distinct localization and attached nature of the hindgut bacteria and the recolonization after each molt suggest they are indigenous to this region of the gut tract. Images PMID:16345618

Klug, M. J.; Kotarski, S.

1980-01-01

294

Antimicrobial resistance characteristics and fitness of Gram-negative fecal bacteria from volunteers treated with minocycline or amoxicillin  

PubMed Central

A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora. Gram-negative facultative anaerobic bacteria were recovered from the feces of healthy adult volunteers administered amoxicillin, minocycline or placebo, and changes determined in antimicrobial resistance (AMR) gene carriage. Seventy percent of the 1039 facultative anaerobic isolates recovered were identified by MALDI-TOF as Escherichia coli. A microarray used to determine virulence and resistance gene carriage demonstrated that AMR genes were widespread in all administration groups, with the most common resistance genes being blaTEM, dfr, strB, tet(A), and tet(B). Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of blaTEM gene carriage was observed, an effect not observed in the other two treatment groups. Detection of virulence genes, including stx1A, indicated not all E. coli were innocuous commensals. Approximately 150 E. coli collected from 6 participants were selected for pulse field gel electrophoresis (PFGE), and a subset used for characterisation of plasmids and Phenotypic Microarrays (PM). PFGE indicated some E. coli clones had persisted in volunteers for up to 1 year, while others were transient. Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates. This study indicates healthy individuals carry bacteria harboring resistance to a variety of antibiotics and biocides in their intestinal tract. Antibiotic administration can have a temporary effect of selecting bacteria, showing co-resistance to multiple antibiotics, some of which can persist within the gut for up to 1 year. PMID:25566232

Kirchner, Miranda; Mafura, Muriel; Hunt, Theresa; Abu-Oun, Manal; Nunez-Garcia, Javier; Hu, Yanmin; Weile, Jan; Coates, Anthony; Card, Roderick; Anjum, Muna F.

2014-01-01

295

Succinyl-CoA:(R)-Benzylsuccinate CoA-Transferase: an Enzyme of the Anaerobic Toluene Catabolic Pathway in Denitrifying Bacteria  

Microsoft Academic Search

Anaerobic microbial toluene catabolism is initiated by addition of fumarate to the methyl group of toluene, yielding (R)-benzylsuccinate as first intermediate, which is further metabolized via b-oxidation to benzoyl- coenzyme A (CoA) and succinyl-CoA. A specific succinyl-CoA:(R)-benzylsuccinate CoA-transferase activating (R)-benzylsuccinate to the CoA-thioester was purified and characterized from Thauera aromatica. The enzyme is fully reversible and forms exclusively the 2-(R)-benzylsuccinyl-CoA

CHRISTINA LEUTWEIN; JOHANN HEIDER

2001-01-01

296

Enumeration, Isolation, and Characterization of N2-Fixing Bacteria from Seawater  

PubMed Central

Marine pelagic N2-fixing bacteria have not, in general, been identified or quantified, since low or negligible rates of N2 fixation have been recorded for seawater when blue-green algae (cyanobacteria) are absent. In the study reported here, marine N2-fixing bacteria were found in all samples of seawater collected and were analyzed by using a most-probable-number (MPN) method. Two different media were used which allowed growth of microaerophiles, as well as that of aerobes and facultative anaerobes. MPN values obtained for N2-fixing bacteria ranged from 0.4 to 1 × 103 per liter for water collected off the coast of Puerto Rico and from 2 to 5.5 × 102 per liter for Chesapeake Bay water. Over 100 strains of N2-fixing bacteria were isolated from the MPN tubes and classified, yielding four major groups of NaCl-requiring bacteria based on biochemical characteristics. Results of differential filtration studies indicate that N2-fixing bacteria may be associated with phytoplankton. In addition, when N2-fixing bacteria were inoculated into unfiltered seawater and incubated in situ, nitrogenase activity could be detected within 1 h. However, no nitrogenase activity was detected in uninoculated seawater or when bacteria were incubated in 0.2-?m-filtered (phytoplankton-free) seawater. The ability of these isolates to fix N2 at ambient conditions in seawater and the large variety of N2-fixing bacteria isolated and identified lead to the conclusion that N2 fixation in the ocean may occur to a greater degree than previously believed. PMID:16346855

Guerinot, Mary Lou; Colwell, Rita R.

1985-01-01

297

Oxidative metabolism of inorganic sulfur compounds by bacteria  

Microsoft Academic Search

The history of the elucidation of the microbiology and biochemistry of the oxidation of inorganic sulfur compounds in chemolithotrophic bacteria is briefly reviewed, and the contribution of Martinus Beijerinck to the study of sulfur-oxidizing bacteria highlighted. Recent developments in the biochemistry, enzymology and molecular biology of sulfur oxidation in obligately and facultatively lithotrophic bacteria are summarized, and the existence of

Donovan P. Kelly; Jasvinder K. Shergill; Wei-Ping Lu; Ann P. Wood

1997-01-01

298

Enhanced hydrolysis and methane yield by applying microaeration pretreatment to the anaerobic co-digestion of brown water and food waste  

SciTech Connect

Highlights: ? Microaeration pretreatment was effective for brown water and food waste mixture. ? The added oxygen was consumed fully by facultative microorganisms. ? Enhanced solubilization, acidification and breakdown of SCFAs to acetate. ? Microaeration pretreatment improved methane yield by 10–21%. ? Nature of inoculum influenced the effects of microaeration. - Abstract: Microaeration has been used conventionally for the desulphurization of biogas, and recently it was shown to be an alternative pretreatment to enhance hydrolysis of the anaerobic digestion (AD) process. Previous studies on microaeration pretreatment were limited to the study of substrates with complex organic matter, while little has been reported on its effect on substrates with higher biodegradability such as brown water and food waste. Due to the lack of consistent microaeration intensities, previous studies were not comparable and thus inconclusive in proving the effectiveness of microaeration to the overall AD process. In this study, the role of microaeration pretreatment in the anaerobic co-digestion of brown water and food waste was evaluated in batch-tests. After a 4-day pretreatment with 37.5 mL-O{sub 2}/L{sub R}-d added to the liquid phase of the reactor, the methane production of substrates were monitored in anaerobic conditions over the next 40 days. The added oxygen was consumed fully by facultative microorganisms and a reducing environment for organic matter degradation was maintained. Other than higher COD solubilization, microaeration pretreatment led to greater VFA accumulation and the conversion of other short chain fatty acids to acetate. This could be due to enhanced activities of hydrolytic and acidogenic bacteria and the degradation of slowly biodegradable compounds under microaerobic conditions. This study also found that the nature of inoculum influenced the effects of microaeration as a 21% and 10% increase in methane yield was observed when pretreatment was applied to inoculated substrates, and substrates without inoculum, respectively.

Lim, Jun Wei [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 06-08 CleanTech One, 1 Cleantech Loop, Singapore 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Wang, Jing-Yuan, E-mail: jywang@ntu.edu.sg [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 06-08 CleanTech One, 1 Cleantech Loop, Singapore 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

2013-04-15

299

Activity of WY-49605 compared with those of amoxicillin, amoxicillin-clavulanate, imipenem, ciprofloxacin, cefaclor, cefpodoxime, cefuroxime, clindamycin, and metronidazole against 384 anaerobic bacteria.  

PubMed Central

The National Committee for Clinical Laboratory Standards agar dilution method was used to compare the in vitro activity of WY-49605 (also called SUN/SY 5555 and ALP-201), a new broad-spectrum oral penem, to those of amoxicillin, amoxicillin-clavulanate, imipenem, ciprofloxacin, cefaclor, cefpodoxime, cefuroxime, clindamycin, and metronidazole against 384 clinically isolated anaerobes. These anaerobic organisms included 90 strains from the Bacteroides fragilis group, 87 Prevotella and Porphyromonas strains, non-B. fragilis group Bacteroides strains, 56 fusobacteria, 55 peptostreptococci, 49 gram-positive non-spore-forming rods, and 47 clostridia. Overall, WY-49605 had an MIC range of 0.015 to 8.0 micrograms/ml, an MIC at which 50% of the isolates are inhibited (MIC50) of 0.25 microgram/ml, and an MIC at which 90% of the isolates are inhibited (MIC90) of 2.0 micrograms/ml. Good activity against all anaerobe groups was observed, except for Clostridium difficile and lactobacilli (MIC50s of 4.0 and 2.0 micrograms/ml, respectively, and MIC90s of 8.0 and 2.0 micrograms/ml, respectively). Imipenem had an MIC50 of 0.03 microgram/ml and an MIC90 of 0.25 microgram/ml. Ciprofloxacin was much less active (MIC50 of 2.0 micrograms/ml and MIC90 of 16.0 micrograms/ml). By comparison, all oral beta-lactams were less active than WY-49605, with susceptibilities as follows: amoxicillin MIC50 of 8.0 micrograms/ml and MIC90 of > 256.0 micrograms/ml), amoxicillin-clavulanate MIC50 of 1.0 microgram/ml and MIC90 of 8.0 micrograms/ml, cefaclor MIC50 of 8.0 micrograms/ml and MIC90 of > 32.0 micrograms/ml, cefpodoxime MIC50 of 4.0 micrograms/ml and MIC90 of > 32.0 micrograms/ml, and cefuroxime MIC50 of 4.0 micrograms/ml and MIC90 of > 32.0 micrograms/ml. Clindamycin was active against all groups except some members of the B. fragilis group, Fusobacterium varium, and some clostridia ( overall MIC50 of 0.5 micrograms/ml and overall MIC90 of 8.0 micrograms/ml). Metronidazole was active (MIC of less than or equal to 4.0 micrograms/ml) against all gram-negative anaerobic rods, but most gram-positive non-spore-forming rods, some peptostreptococci, and some clostridia were less susceptible. To date, WY-49605 is the most active oral beta-lactam against anaerobes: these results suggest clinical evaluation for clinical indications suitable for oral therapy. PMID:7872754

Spangler, S K; Jacobs, M R; Appelbaum, P C

1994-01-01

300

Worldwide populations of the aphid Aphis craccivora are infected with diverse facultative bacterial symbionts.  

PubMed

Facultative bacterial endosymbionts can play an important role in the evolutionary trajectory of their hosts. Aphids (Hemiptera: Aphididae) are infected with a wide variety of facultative endosymbionts that can confer ecologically relevant traits, which in turn may drive microevolutionary processes in a dynamic selective environment. However, relatively little is known about how symbiont diversity is structured in most aphid species. Here, we investigate facultative symbiont species richness and prevalence among world-wide populations of the cowpea aphid, Aphis craccivora Koch. We surveyed 44 populations of A. craccivora, and detected 11 strains of facultative symbiotic bacteria, representing six genera. There were two significant associations between facultative symbiont and aphid food plant: the symbiont Arsenophonus was found at high prevalence in A. craccivora populations collected from Robinia sp. (locust), whereas the symbiont Hamiltonella was almost exclusively found in A. craccivora populations from Medicago sativa (alfalfa). Aphids collected from these two food plants also had divergent mitochondrial haplotypes, potentially indicating the formation of specialized aphid lineages associated with food plant (host-associated differentiation). The role of facultative symbionts in this process remains to be determined. Overall, observed facultative symbiont prevalence in A. craccivora was lower than that of some other well-studied aphids (e.g., Aphis fabae and Acyrthosiphon pisum), possibly as a consequence of A. craccivora's almost purely parthenogenetic life history. Finally, most (70 %) of the surveyed populations were polymorphic for facultative symbiont infection, indicating that even when symbiont prevalence is relatively low, symbiont-associated phenotypic variation may allow population-level evolutionary responses to local selection. PMID:24233285

Brady, Cristina M; Asplen, Mark K; Desneux, Nicolas; Heimpel, George E; Hopper, Keith R; Linnen, Catherine R; Oliver, Kerry M; Wulff, Jason A; White, Jennifer A

2014-01-01

301

Abundance and diversity of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)-metabolizing bacteria in UXO-contaminated marine sediments.  

PubMed

Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) is a toxic explosive known to be resistant to biodegradation. In this study, we found that sediment collected from two unexploded ordnance (UXO) disposal sites (UXO-3, UXO-5) and one nearby reference site (midref) in Hawaii contained anaerobic bacteria capable of removing HMX. Two groups of HMX-removing bacteria were found in UXO-5: group I contained aerotolerant anaerobes and microaerophiles, and group II contained facultative anaerobes. In UXO-3 and midref sediments, HMX-metabolizing bacteria were strictly anaerobic (group III and group IV). Using 16S rRNA sequencing, group I was assigned to a novel phylogenetic cluster of Clostridiales, and groups II and III were related to Paenibacillus and Tepidibacter of Firmicutes, respectively. Group IV bacteria were identified as Desulfovibrio of Deltaproteobacteria. Using [UL-(14)C]-HMX, group IV isolates were found to mineralize HMX (26.8% in 308 d) as determined by liberated (14)CO(2), but negligible mineralization was observed in groups I-III. Resting cells of isolates metabolized HMX to N(2)O and HCHO via the intermediary formation of 1-nitroso-octahydro-3,5,7-trinitro-1,3,5,7-tetrazocine together with methylenedinitramine. These experimental findings suggest that HMX biotransformation occurred either via initial denitration followed by ring cleavage or via reduction of one or more of the N-NO(2) group(s) to the corresponding N-NO bond(s) prior to ring cleavage. PMID:17381523

Zhao, Jian-Shen; Manno, Dominic; Hawari, Jalal

2007-03-01

302

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

PubMed

The digestion and Volatile Fatty Acid (VFA) production from rice straw and oil palm fronds by cellulolytic bacteria isolated from the termite Coptotermes curvignathus were investigated. The bacteria were Acinetobacter strain Raminalimon, Enterobacter aerogenes strain Razmin C, Enterobacter cloacae strain Razmin B, Bacillus cereus strain Razmin A and Chryseobacterium kwangyangense strain Cb. Acinetobacter strain Raminalimon is an aerobic bacterium, while the other species are facultative anaerobes. There were significant differences (p<0.05) among the bacteria for Dry Matter (DM) lost and acetic acid production from rice straw and Acinetobacter strain Raminalimon showed the highest activity. The facultative bacteria C. kwangyangense strain Cb (cfu mL(-1) 231 x 10(-6), OD: 0.5), E. cloacae (cfu mL(-1) 68 x 10(-7), OD: 0.5) and E. aerogenes (cfu mL(-1) 33 x 10(-7), OD: 0.5) were used for digestion study with the rumen fluid microflora. The in vitro gas production technique was applied for the comparative study and the parameters measured were pH, gas (volume), dry matter lost, acetic acid, propionic acid and butyric acid concentrations. pH was not significantly (p<0.05) different among the five treatments. The bacterium C. kwangyangense strain Cb showed the highest activity (p<0.05) for DM lost, acetic acid, propionic acid and butyric acid production from rice straw when compared to the other bacterial activities. There was no significance (p<0.05) difference between the three bacteria for the dry matter lost of oil palm fronds but the production of Volatile Fatty Acids (VFA) was significantly (p<0.05) high in the treatment which was inoculated with C. kwangyangense strain Cb. The Gen Bank NCBI/EMBL accession numbers for the bacterial strains are EU332791, EU305608, EU305609, EU294508 and EU169201. PMID:18817130

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

2008-02-15

303

Contamination pathways of spore-forming bacteria in a vegetable cannery.  

PubMed

Spoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. Here, we performed a bacterial survey over two consecutive years on the processing line of a French company manufacturing canned mixed green peas and carrots. In total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. Thermophilic and highly-heat-resistant thermophilic spores growing anaerobically were counted. During vegetable preparation, anaerobic spore counts were significantly decreased, and tended to remain unchanged further downstream in the process. Large variation of spore levels in products immediately before the sterilization process could be explained by occasionally high spore levels on surfaces and in debris of vegetable combined with long residence times in conditions suitable for growth and sporulation. Vegetable processing was also associated with an increase in the prevalence of highly-heat-resistant species, probably due to cross-contamination of peas via blanching water. Geobacillus stearothermophilus M13-PCR genotypic profiling on 112 isolates determined 23 profile-types and confirmed process-driven cross-contamination. Taken together, these findings clarify the scheme of contamination pathway by thermophilic spore-forming bacteria in a vegetable cannery. PMID:25755080

Durand, Loïc; Planchon, Stella; Guinebretiere, Marie-Hélène; André, Stéphane; Carlin, Frédéric; Remize, Fabienne

2015-06-01

304

[Susceptibility of potential periodontopathic bacteria to metronidazole, spiramycin and their combination].  

PubMed

A total of 65 bacterial strains originating mostly from subgingival plaque were tested for their susceptibilities to metronidazole, spiramycin, and their combination, ornidazole, erythromycin and tetracycline by means of an agar dilution technique. All agents were active against all anaerobic Gram-negative rods. Bacteroides gingivalis and Fusobacterium nucleatum showed marked susceptibility to metronidazole (MIC less than or equal to 0.06 microgram/ml) whereas 4-64 micrograms/ml were required to inhibit the capnophilic Actinobacillus actinomycetemcomitans and Capnocytophaga. Gram-positive facultatives were resistant to nitro-imidazoles but were inhibited at macrolide concentrations less than or equal to 0.5 microgram/ml. Except for F. nucleatum and Veillonella strains (2 less than or equal to MIC less than or equal to 128 micrograms/ml) macrolides were active against all other anaerobic bacteria tested. At concentrations less than or equal to 2 micrograms/ml the combination of spiramycin and metronidazole (2 : 1) was active against virtually all bacteria tested but our results failed to show a synergistic effect. PMID:6584423

Mouton, C; Dextraze, L; Mayrand, D

1984-03-01

305

N2 fixation in marine heterotrophic bacteria: dynamics of environmental and molecular regulation.  

PubMed Central

Molecular and immunological techniques were used to examine N2 fixation in a ubiquitous heterotrophic marine bacterium, the facultative anaerobic Vibrio natriegens. When batch cultures were shifted from aerobic N-replete to anaerobic N-deplete conditions, transcriptional and post-translational regulation of N2 fixation was observed. Levels of nifHDK mRNA encoding the nitrogenase enzyme were highest at 140 min postshift and undetectable between 6 and 9 h later. Immunologically determined levels of nitrogenase enzyme (Fe protein) were highest between 6 and 15 h postshift, and nitrogenase activity peaked between 6 and 9 h postshift, declining by a factor of 2 after 12-15 h. Unlike their regulation in cyanobacteria, Fe protein and nitrogenase activity were present when nifHDK mRNA was absent in V. natriegens, indicating that nitrogenase is stored and stable under anaerobic conditions. Both nifHDK mRNA and Fe protein disappeared within 40 min after cultures were shifted from N2-fixing conditions (anaerobic, N-deplete) to non- N2-fixing conditions (aerobic, N-enriched) but reappeared when shifted to conditions favoring N2 fixation. Thus, unlike other N2-fixing heterotrophic bacteria, nitrogenase must be resynthesized after aerobic exposure in V. natriegens. Immunological detection based on immunoblot (Western) analysis and immunogold labeling correlated positively with nitrogenase activity; no localization of nitrogenase was observed. Because V. natriegens continues to fix N2 for many hours after anaerobic induction, this species may play an important role in providing "new" nitrogen in marine ecosystems. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:11607653

Coyer, J A; Cabello-Pasini, A; Swift, H; Alberte, R S

1996-01-01

306

Enhancement of anaerobic acidogenesis by integrating an electrochemical system into an acidogenic reactor: effect of hydraulic retention times (HRT) and role of bacteria and acidophilic methanogenic Archaea.  

PubMed

In this study, an acidogenic reactor packed with a pair of Fe-carbon electrodes (R1) was developed to enhance anaerobic acidogenesis of organic wastewater at short hydraulic retention times. The results indicated that the acidogenic efficiency was improved by settling a bio-electrochemical system. When hydraulic retention times decreased from 12 to 3h, R1 showed 18.9% more chemical oxygen demand removal and 13.8% more acidification efficiency. After cutting off the voltage of R1, the COD removal decreased by about 5%. Coupling of Fe(2+) leaching and electric field accelerated the hydrolysis of polysaccharide, relieving its accumulation in the sludge phase. Several acidophilic methanogenic Archaea such as Methanosarcina sp. were enriched in R1, which was favorable for consuming organic acids and preventing excessive pH decline. Thus, the developed acidogenic reactor with Fe-carbon electrodes is expected to be potentially effective and useful for wastewater treatment. PMID:25514401

Zhang, Jingxin; Zhang, Yaobin; Quan, Xie; Chen, Shuo

2015-03-01

307

Antibiotic susceptibilities of periodontal bacteria. In vitro susceptibilities to eight antimicrobial agents.  

PubMed

In vitro susceptibilities of 369 to 966 bacterial isolates from periodontal lesions to eight antibiotics were determined by agar dilution technique as a means of determining which antimicrobial agents were inhibitory for bacteria frequently associated with destructive periodontal diseases. Although most bacteria were relatively susceptible to the penicillins, greater activity was generally noted with amoxicillin than with either penicillin or ampicillin with the exception of Selenomonas sputigena and Peptostreptococcus. Antibacterial activities obtained with minocycline were significantly higher than with tetracycline for Actinobacillus actinomycetemcomitans and Streptococcus but comparable for most other taxa. Clindamycin and metronidazole both demonstrated excellent activity against the anaerobic Gram-negative rods but were less effective against some of the capnophilic and facultative organisms. Eikenella corrodens was exceptionally resistant to both of these drugs; and A. actinomycetemcomitans was generally resistant to clindamycin but relatively susceptible to metronidazole. Erythromycin was considerably less active than the other antibiotics against the majority of the periodontal bacteria. No single antibiotic, at concentrations equivalent to those achieved in body fluids, was uniformly effective in inhibiting all bacteria currently implicated or suspected as etiologic agents of periodontal diseases. PMID:3866054

Walker, C B; Pappas, J D; Tyler, K Z; Cohen, S; Gordon, J M

1985-11-01

308

Sulfate-reducing bacteria and their activities in cyanobacterial mats of Solar Lake (Sinai, Egypt)  

SciTech Connect

The sulfate-reducing bacteria within the surface layer of the hypersaline cyanobacterial mat of Solar Lake (Sinai, Egypt) were investigated with combined microbiological, molecular, and biogeochemical approaches. The diurnally oxic surface layer contained between 10{sup 6} and 10{sup 7} cultivable sulfate-reducing bacteria ml{sup {minus}1} day{sup {minus}1}, both in the same range as and sometimes higher than those in anaerobic deeper mat layers. In the oxic surface layer and in the mat layers below, filamentous sulfate-reducing Desulfonema bacteria were found in variable densities of 10{sup 4} and 10{sup 6} cells ml{sup {minus}1}. A Desulfonema-related, diurnally migrating bacterium was detected with PCR and denaturing gradient gel electrophoresis within and below the oxic surface layer. Facultative aerobic respiration, filamentous morphology, motility, diurnal migration, and aggregate formation were the most conspicuous adaptations of Solar Lake sulfate-reducing bacteria to the mat matrix and to diurnal oxygen stress. A comparison of sulfate reduction rates within the mat and previously published photosynthesis rates showed that CO{sub 2} from sulfate reduction in the upper 5 mm accounted for 7 to 8% of the total photosynthetic CO{sub 2} demand of the mat.

Teske, A.; Ramsing, N.B.; Habicht, K.; Kuever, J.; Joergensen, B.B. [Max Planck Inst. for Marine Microbiology, Bremen (Germany); Fukui, Manabu [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan); Cohen, Y. [Hebrew Univ. of Jerusalem (Israel)

1998-08-01

309

A comparison of primer sets for detecting 16S rRNA and hydrazine oxidoreductase genes of anaerobic ammonium-oxidizing bacteria in marine sediments  

Microsoft Academic Search

Published polymerase chain reaction primer sets for detecting the genes encoding 16S rRNA gene and hydrazine oxidoreductase\\u000a (hzo) in anammox bacteria were compared by using the same coastal marine sediment samples. While four previously reported primer\\u000a sets developed to detect the 16S rRNA gene showed varying specificities between 12% and 77%, an optimized primer combination\\u000a resulted in up to 98%

Meng Li; Yiguo Hong; Martin Gunter Klotz; Ji-Dong Gu

2010-01-01

310

Time-Resolved DNA Stable Isotope Probing Links Desulfobacterales- and Coriobacteriaceae-Related Bacteria to Anaerobic Degradation of Benzene under Methanogenic Conditions  

PubMed Central

To identify the microorganisms involved in benzene degradation, DNA-stable isotope probing (SIP) with 13C-benzene was applied to a methanogenic benzene-degrading enrichment culture. Pyrosequencing of ribosomal RNA (rRNA) gene sequences revealed that the community structure was highly complex in spite of a 3-year incubation only with benzene. The culture degraded 98% of approximately 1 mM 13C-benzene and mineralized 72% of that within 63 d. The terminal restriction fragment length polymorphism (T-RFLP) profiles of the buoyant density fractions revealed the incorporation of 13C into two phylotypes after 64 d. These two phylotypes were determined to be Desulfobacterales- and Coriobacteriaceae-related bacteria by cloning and sequencing of the 16S rRNA gene in the 13C-labeled DNA abundant fraction. Comparative pyrosequencing analysis of the buoyant density fractions of 12C- and 13C-labeled samples indicated the incorporation of 13C into three bacterial and one archaeal OTUs related to Desulfobacterales, Coriobacteriales, Rhodocyclaceae, and Methanosarcinales. The first two OTUs included the bacteria detected by T-RFLP-cloning-sequencing analysis. Furthermore, time-resolved SIP analysis confirmed that the activity of all these microbes appeared at the earliest stage of degradation. In this methanogenic culture, Desulfobacterales- and Coriobacteriaceae-related bacteria were most likely to be the major benzene degraders. PMID:24909708

Noguchi, Mana; Kurisu, Futoshi; Kasuga, Ikuro; Furumai, Hiroaki

2014-01-01

311

Siderophore Production by Pseudomonas stutzeri under Aerobic and Anaerobic Conditions?  

PubMed Central

The siderophore production of the facultative anaerobe Pseudomonas stutzeri, strain CCUG 36651, grown under both aerobic and anaerobic conditions, was investigated by liquid chromatography and mass spectrometry. The bacterial strain has been isolated at a 626-m depth at the Äspö Hard Rock Laboratory, where experiments concerning the geological disposal of nuclear waste are performed. In bacterial culture extracts, the iron in the siderophore complexes was replaced by gallium to facilitate siderophore identification by mass spectrometry. P. stutzeri was shown to produce ferrioxamine E (nocardamine) as the main siderophore together with ferrioxamine G and two cyclic ferrioxamines having molecular masses 14 and 28 atomic mass units lower than that of ferrioxamine E, suggested to be ferrioxamine D2 and ferrioxamine X1, respectively. In contrast, no siderophores were observed from anaerobically grown P. stutzeri. None of the siderophores produced by aerobically grown P. stutzeri were found in anaerobic natural water samples from the Äspö Hard Rock Laboratory. PMID:17675442

Essén, Sofia A.; Johnsson, Anna; Bylund, Dan; Pedersen, Karsten; Lundström, Ulla S.

2007-01-01

312

The potential of bacteria isolated from ruminal contents of seaweed-eating North Ronaldsay sheep to hydrolyse seaweed components and produce methane by anaerobic digestion in vitro  

PubMed Central

The production of methane biofuel from seaweeds is limited by the hydrolysis of polysaccharides. The rumen microbiota of seaweed-eating North Ronaldsay sheep was studied for polysaccharidic bacterial isolates degrading brown-seaweed polysaccharides. Only nine isolates out of 65 utilized > 90% of the polysaccharide they were isolated on. The nine isolates (eight Prevotella spp. and one Clostridium butyricum) utilized whole Laminaria hyperborea extract and a range of seaweed polysaccharides, including alginate (seven out of nine isolates), laminarin and carboxymethylcellulose (eight out of nine isolates); while two out of nine isolates additionally hydrolysed fucoidan to some extent. Crude enzyme extracts from three of the isolates studied further had diverse glycosidases and polysaccharidase activities; particularly against laminarin and alginate (two isolates were shown to have alginate lyase activity) and notably fucoidan and carageenan (one isolate). In serial culture rumen microbiota hydrolysed a range of seaweed polysaccharides (fucoidan to a notably lesser degree) and homogenates of L. hyperborea, mixed Fucus spp. and Ascophyllum nodosum to produce methane and acetate. The rumen microbiota and isolates represent potential adjunct organisms or enzymes which may improve hydrolysis of seaweed components and thus improve the efficiency of seaweed anaerobic digestion for methane biofuel production. PMID:23170956

Williams, Allan G; Withers, Susan; Sutherland, Alastair D

2013-01-01

313

Carbon and hydrogen stable isotope fractionation associated with the anaerobic degradation of propane and butane by marine sulfate-reducing bacteria.  

PubMed

The anaerobic degradation of propane and butane is typically initiated by activation via addition to fumarate. Here we investigated the mechanism of activation under sulfate-reducing conditions by one pure culture (strain BuS5) and three enrichment cultures employing stable isotope analysis. Stable isotope fractionation was compared for cultures incubated with or without substrate diffusion limitation. Bulk enrichment factors were significantly higher in mixed vs. static incubations. Two dimensional factors, given by the correlation of stable isotope fractionation of both carbon and hydrogen at their reactive positions (Lambda reactive position, ?rp), were compared to analyse the activation mechanisms. A characteristic reactive position isotope fractionation pattern was observed, distinct from aerobic degradation. ?rp values ranged from 10.5 to 11.8 for propane and from 7.8 to 9.4 for butane. Incubations of strain BuS5 with deuterium-labelled n-alkanes indicated that butane was activated solely at the subterminal C atom. In contrast, propane was activated mainly at the subterminal C atom but also significantly at the terminal C atoms. A conservative estimate suggests that about 70% of the propane activation events occurred at the subterminal C atom and about 30% at the terminal C atoms. PMID:24028539

Jaekel, Ulrike; Vogt, Carsten; Fischer, Anko; Richnow, Hans-Hermann; Musat, Florin

2014-01-01

314

Comparative in vitro activity of 1-oxa-beta-lactam (LY127935) and cefoperazone with other beta-lactam antibiotics against anaerobic bacteria.  

PubMed

The in vitro activity of 1-oxa-beta-lactam (LY127935), cefoperazone (T-1551), cefuroxime, cefsulodin, cefaclor, cefotaxime, and cefoxitin on 85 anaerobic clinical isolates (30 Bacteroides, 30 Clostridium, 25 Peptococcaceae) was simultaneously determined by the agar dilution test in two different media, Brucella Agar (Difco Laboratories) and Wilkins-Chalgren agar. In Wilkins-Chalgren agar, 90% of Bacteroides were inhibited by (micrograms per milliliter): LY127935, 0.5; T-1551, 64; cefoxitin or cefuroxime, 8; cefsulodin or cefotaxime, 32; and cefaclor, 128. All Clostridia were inhibited in Wilkins-Chalgren by (micrograms per milliliter): LY127935, 4; T-1551, 2; cefoxitin, 6; cefuroxime, 0.12; cefsulodin, 0.5; cefaclor, 1; and cefotaxime, 8. All Peptococccaceae were inhibited by T-1551, cefsulodin or cefotaxime at 4 microgram/ml and by cefoxitin or cefuroxime at 1 to 2 microgram/ml. With cefaclor at 8 microgram/ml, 92% of strains were inhibited, and LY127935 at 16 microgram/ml only inhibited 64% of strains. LY127935 was the most active of the antibiotics tested against Bacteroides, showing good activity against Clostridia and poor activity on Peptococcaceae, whereas T-1551 was more active against Peptococccaceae and had similar activity against Clostridia and poor activity on Bacteroides. There are no significant differences between minimal inhibitory concentrations obtained in Brucella Agar and those obtained in Wilkins-Chalgren. PMID:6247966

Borobio, M V; Aznar, J; Jimenez, R; Garcia, F; Perea, E J

1980-02-01

315

Complete genome sequences for the anaerobic, extremely thermophilic plant biomass-degrading bacteria Caldicellulosiruptor hydrothermalis, Caldicellulosiruptor kristjanssonii, Caldicellulosiruptor kronotskyensis, Caldicellulosiruptor owensenis, and Caldicellulosiruptor lactoaceticus  

SciTech Connect

The genus Caldicellulosiruptor contains the most thermophilic, plant biomass-degrading bacteria isolated to date. Previously, genome sequences from three cellulolytic members of this genus were reported (C. saccharolyticus, C. bescii, and C. obsidiansis). To further explore the physiological and biochemical basis for polysaccharide degradation within this genus, five additional genomes were sequenced: C. hydrothermalis, C. kristjanssonii, C. kronotskyensis, C. lactoaceticus, and C. owensensis. Taken together, the seven completed and one draft-phase Caldicellulosiruptor genomes suggest that, while central metabolism is highly conserved, significant differences in glycoside hydrolase inventories and numbers of carbohydrate transporters exist, a finding which likely relates to variability observed in plant biomass degradation capacity.

Blumer-Schuette, Sara E. [North Carolina State University; Ozdemir, Inci [North Carolina State University; Mistry, Dhaval [North Carolina State University; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [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); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Walston Davenport, Karen [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Adams, Michael W. W. [University of Georgia, Athens, GA; Kelly, Robert M [North Carolina State University

2011-01-01

316

NADH-linked aldose reductase: the key to anaerobic alcoholic fermentation of xylose by yeasts  

Microsoft Academic Search

The kinetics and enzymology of d-xylose utilization were studied in aerobic and anaerobic batch cultures of the facultatively fermentative yeasts Candida utilis, Pachysolen tannophilus, and Pichia stipitis. These yeasts did not produce ethanol under aerobic conditions. When shifted to anaerobiosis cultures of C. utilis did not show fermentation of xylose; in Pa. tannophilus a very low rate of ethanol formation

Peter M. Bruinenberg; Peter H. M. Bot; Johannes P. Dijken; W. Alexander Scheffers

1984-01-01

317

Evolution and Diversity of Facultative Symbionts from the Aphid Subfamily Lachninae? †  

PubMed Central

Many aphids harbor a variety of endosymbiotic bacteria. The functions of these symbionts can range from an obligate nutritional role to a facultative role in protecting their hosts against environmental stresses. One such symbiont is “Candidatus Serratia symbiotica,” which is involved in defense against heat and potentially also in aphid nutrition. Lachnid aphids have been the focus of several recent studies investigating the transition of this symbiont from a facultative symbiont to an obligate symbiont. In a phylogenetic analysis of Serratia symbionts from 51 lachnid hosts, we found that diversity in symbiont morphology, distribution, and function is due to multiple independent origins of symbiosis from ancestors belonging to Serratia and possibly also to evolution within distinct symbiont clades. Our results do not support cocladogenesis of “Ca. Serratia symbiotica” with Cinara subgenus Cinara species and weigh against an obligate nutritional role. Finally, we show that species belonging to the subfamily Lachninae have a high incidence of facultative symbiont infection. PMID:19542349

Burke, Gaelen R.; Normark, Benjamin B.; Favret, Colin; Moran, Nancy A.

2009-01-01

318

Activities of four frog skin-derived antimicrobial peptides (temporin-1DRa, temporin-1Va and the melittin-related peptides AR-23 and RV-23) against anaerobic bacteria.  

PubMed

The activities of two antimicrobial peptides belonging to the temporin family (temporin-1DRa from Rana draytonii and temporin-1Va from Rana virgatipes) and two peptides with structural similarity to the bee venom peptide melittin (AR-23 from Rana tagoi and RV-23 from R. draytonii) were evaluated against a range of reference strains and clinical isolates of anaerobic bacteria. These peptides were selected because they show broad-spectrum growth inhibitory activity against reference strains of several medically important aerobic microorganisms and against clinical isolates of methicillin-resistant Staphylococcus aureus. All peptides showed relatively high potency (minimum inhibitory concentration (MIC)

Urbán, Edit; Nagy, Elisabeth; Pál, Tibor; Sonnevend, Agnes; Conlon, J Michael

2007-03-01

319

An investigation into the removal of Salmonella and enteric indicator bacteria from the separated liquid fraction of raw or anaerobically digested pig manure using novel on-farm woodchip biofilters.  

PubMed

The objective was to investigate the removal of Salmonella and enteric indicator bacteria from the liquid fraction of raw and anaerobically digested (AD) pig manure in woodchip biofilters over a 14week (98day) period. Antibiotic susceptible Salmonella Infantis was detected in one influent material (liquid fraction of raw manure) on two occasions but was not found in the effluent at any time point. Furthermore, mean coliform reductions of 56% were observed in the biofilters treating the liquid fraction of raw manure. However, a mean increase of 228% was found in those treating the liquid from AD manure, despite the fact that the microbial challenge to these biofilters was lower. In addition, relatively high coliform counts were still present in the effluent from both biofilter treatments, especially in the systems treating the liquid fraction of AD manure. However, findings for Escherichia coli and Enterococcus were more promising, with reductions observed for both treatments (10 and 18.5% for E. coli and 71 and 87% for Enterococcus). Moreover, E. coli and Enterococcus were at, or just above, the limit of detection in the final effluents. Overall, although, there are no microbial limits for discharge or washwaters, the woodchip filter effluent would appear safe for discharge to waterways or use on-farm as regards Salmonella, E. coli and Enterococcus but not coliform. In conclusion, woodchip biofilters offer potential as a low-cost sustainable novel treatment option for the removal of pathogens from the liquid fraction of pig manure. PMID:25659312

McCarthy, G; Lawlor, P G; Carney, K N; Zhan, X; Gutierrez, M; Gardiner, G E

2015-05-01

320

Physiology, biochemistry, and genetics of a pure culture of an obligatory anaerobic bacterium that utilizes 2,4,-6-trinitrotoluene (TNT) and biodegradation of RDX by pure cultures of obligatory anaerobic bacteria of the genus clostridium. Final report, 1 September 1993-31 August 1996  

SciTech Connect

In work supported by the US AFOSR (grant F49620-94-1-0306) we are conducting detailed biochemical and genetic studies of three strains of Clostridium bifernientans, obligatory anaerobic bacteria that appear to completely degrade a variety of nitroaromatic compounds, including 2,4,6-trinitrotoluene (TNT). We are determining the optimal physiological conditions for the degradative activities of C. bifermentans strains; and identifying and characterizing enzymes and genes involved in the biotransformation of nitroaromatic compounds by C. bifermentans. In our AASERT supplemental grant(AFOSR-93-1-O464) we expanded these goals to the explosive RDX (1,3,5-triaza-1, 3,5-trinitrocyclohexane). The AASERT grant funded two graduate students, who characterized the ability of C. bifermentans to degrade RDX (Regan, K. N., and R.L. Crawford, 1994. Biotechnol. Kett. 16: 1081- 1086), and prepared both genomic and plasmid DNA libraries from C. bifermentans. This genetic work will accelerate our progress toward our goal of characterizing the genetics of TNT/RDx degradation by our clostridia (K. Diedrich, M.S. thesis, University of Idaho; in preparation).

Crawford, R.L.; Crawford, D.L.

1996-09-01

321

Isolation and Identification of Cellulolytic Bacteria from the Gut of Holotrichia parallela Larvae (Coleoptera: Scarabaeidae)  

PubMed Central

In this study, 207 strains of aerobic and facultatively anaerobic cellulolytic bacteria were isolated from the gut of Holotrichia parallela larvae. These bacterial isolates were assigned to 21 genotypes by amplified ribosomal DNA restriction analysis (ARDRA). A partial 16S rDNA sequence analysis and standard biochemical and physiological tests were used for the assignment of the 21 representative isolates. Our results show that the cellulolytic bacterial community is dominated by the Proteobacteria (70.05%), followed by the Actinobacteria (24.15%), the Firmicutes (4.35%), and the Bacteroidetes (1.45%). At the genus level, Gram-negative bacteria including Pseudomonas, Ochrobactrum, Rhizobium, Cellulosimicrobium, and Microbacterium were the predominant groups, but members of Bacillus, Dyadobacter, Siphonobacter, Paracoccus, Kaistia, Devosia, Labrys, Ensifer, Variovorax, Shinella, Citrobacter, and Stenotrophomonas were also found. Furthermore, our results suggest that a significant amount of bacterial diversity exists among the cellulolytic bacteria, and that Siphonobacter aquaeclarae, Cellulosimicrobium funkei, Paracoccus sulfuroxidans, Ochrobactrum cytisi, Ochrobactrum haematophilum, Kaistia adipata, Devosia riboflavina, Labrys neptuniae, Ensifer adhaerens, Shinella zoogloeoides, Citrobacter freundii, and Pseudomonas nitroreducens are reported to be cellulolytic for the first time in this study. Our results indicate that the scarab gut is an attractive source for the study of novel cellulolytic microorganisms and enzymes useful for cellulose degradation. PMID:22489111

Huang, Shengwei; Sheng, Ping; Zhang, Hongyu

2012-01-01

322

Tinidazole--microbiology, pharmacology and efficacy in anaerobic infections.  

PubMed

Tinidazole is a 5-nitroimidazole with selective activity against anaerobic bacteria and protozoa. It is bactericidal at low concentrations and its spectrum covers most anaerobic bacteria and some capnophilic microorganisms. Anaerobic bacteria known to be resistant to tinidazole include anaerobic streptococci, actinomyces and propionibacteria. Tinidazole is one of the most active antibacterial agents against Bacteroides fragilis which is one of the most resistant species of anaerobic bacteria. Only a few strains have been reported to be resistant. Tinidazole has been shown to be efficacious in protozoal infections such as trichomonal vaginitis, amoebiasis and giardiasis. Clinical studies have also shown that tinidazole is efficacious in the treatment of anaerobic infections including respiratory tract infections, intra-abdominal sepsis and obstetrical and gynecological infections. Since tinidazole has no activity against aerobic bacteria, it must be combined with other antibacterial agents in the treatment of mixed infections involving aerobic and anaerobic bacteria. Tinidazole has also been used successfully alone or in combination with other antimicrobial agents for prophylaxis in patients undergoing elective colonic and abdominal surgery, emergency appendectomy and gynecological surgery. PMID:6341253

Nord, C E; Kager, L

1983-01-01

323

Anaerobic Infections  

MedlinePLUS

... doctor may treat it with intravenous antibiotics (eg, penicillin, ampicillin) for 4 to 6 weeks, followed by ... In most cases, the bacteria are resistant to penicillin drugs. If an abscess has formed, it may ...

324

Comparative performance evaluation of full-scale anaerobic and aerobic wastewater treatment processes in Brazil.  

PubMed

This article evaluates and compares the actual behavior of 166 full-scale anaerobic and aerobic wastewater treatment plants in operation in Brazil, providing information on the performance of the processes in terms of the quality of the generated effluent and the removal efficiency achieved. The observed results of effluent concentrations and removal efficiencies of the constituents BOD, COD, TSS (total suspended solids), TN (total nitrogen), TP (total phosphorus) and FC (faecal or thermotolerant coliforms) have been compared with the typical expected performance reported in the literature. The treatment technologies selected for study were: (a) predominantly anaerobic: (i) septic tank + anaerobic filter (ST + AF), (ii) UASB reactor without post-treatment (UASB) and (iii) UASB reactor followed by several post-treatment processes (UASB + POST); (b) predominantly aerobic: (iv) facultative pond (FP), (v) anaerobic pond followed by facultative pond (AP + FP) and (vi) activated sludge (AS). The results, confirmed by statistical tests, showed that, in general, the best performance was achieved by AS, but closely followed by UASB reactor, when operating with any kind of post-treatment. The effluent quality of the anaerobic processes ST + AF and UASB reactor without post-treatment was very similar to the one presented by facultative pond, a simpler aerobic process, regarding organic matter. PMID:19151481

von Sperling, M; Oliveira, S C

2009-01-01

325

Mucin degradation in the human colon: production of sialidase, sialate O-acetylesterase, N-acetylneuraminate lyase, arylesterase, and glycosulfatase activities by strains of fecal bacteria.  

PubMed Central

Oligosaccharide side chains of human colonic mucins contain O-acetylated sialic acids and glycosulfate esters. Although these substituents are considered to protect the chains against degradation by bacterial glycosidases, sialate O-acetylesterase, N-acetylneuraminate lyase, and glycosulfatase activities have been found in fecal extracts. To better define the source of these activities, we measured extracellular and cell-bound sialidase, sialate O-acetylesterase, N-acetylneuraminate lyase, arylesterase, and glycosulfatase activities produced by 23 isolates of human fecal bacteria grown anaerobically in a hog gastric mucin culture medium; these represented dominant populations of fecal anaerobes, facultative anaerobes, and the subset of mucin oligosaccharide-degrading bacteria. Every strain produced sialidase and high levels of arylesterase, and all but five facultative anaerobes produced sialate O-acetylesterase. Sialic acids containing 2 mol or more of O-acetyl ester per mol of sialic acid were cleaved from mucin glycoproteins more slowly by sialidases of mucin oligosaccharide-degrading stains than were sialic acids containing 1 or 0 mol, and only N-acetyl- and mono-O-acetylated sialic acids were recovered from enzyme digests of a mucin containing di-O-acetylated sialic acids. No detectable N-acetylneuraminate lyase activity was produced by any strain, but low activity was induced by increasing the glycoprotein-bound sialic acid concentration in the culture medium of six Escherichia coli strains. Using lactitol-6-sulfate as a substrate, we found weak glycosulfatase activity in the partially purified, concentrated enzyme mixture in the culture supernatants of four mucin oligosaccharide-degrading strains but in none of the unconcentrated culture fractions. We conclude that the presence of two or more O-acetyl groups on sialic acids inhibits enteric bacterial sialidases but that production of sialate O-acetylesterases by several populations of enteric bacteria lessens the likelihood that mucin oligosaccharide chains terminating in O-acetylated sialic acids are protected from degradation. Sialate O-acetylesterases have a role in bacterial degradation of mucin glycoproteins in the human colon. Images PMID:1398908

Corfield, A P; Wagner, S A; Clamp, J R; Kriaris, M S; Hoskins, L C

1992-01-01

326

ANAMMOX process start up and stabilization with an anaerobic seed in Anaerobic Membrane Bioreactor (AnMBR)  

Microsoft Academic Search

ANaerobic AMMonium OXidation (ANAMMOX) process, an advanced biological nitrogen removal alternative to traditional nitrification – denitrification removes ammonia using nitrite as the electron acceptor without oxygen. The feasibility of enriching anammox bacteria from anaerobic seed culture to start up an Anaerobic Membrane Bioreactor (AnMBR) for N-removal is reported in this paper. The Anammox activity was established in the AnMBR with

S. Suneethi; Kurian Joseph

2011-01-01

327

Clinical medicine—Mini review Animal models simulating anaerobic infections  

Microsoft Academic Search

Animal models simulating human disease have played an important role in our understanding of the pathogenesis and treatment of infections caused by obligately anaerobic bacteria. These models helped document the primary source of such infections as the host's own normal microflora. In addition, the polymicrobial nature of anaerobic infections was documented by using animal models for intraabdominal sepsis. Subsequent studies

Andrew B. Onderdonk

328

Biochemistry and Evolution of Anaerobic Energy Metabolism in Eukaryotes  

PubMed Central

Summary: Major insights into the phylogenetic distribution, biochemistry, and evolutionary significance of organelles involved in ATP synthesis (energy metabolism) in eukaryotes that thrive in anaerobic environments for all or part of their life cycles have accrued in recent years. All known eukaryotic groups possess an organelle of mitochondrial origin, mapping the origin of mitochondria to the eukaryotic common ancestor, and genome sequence data are rapidly accumulating for eukaryotes that possess anaerobic mitochondria, hydrogenosomes, or mitosomes. Here we review the available biochemical data on the enzymes and pathways that eukaryotes use in anaerobic energy metabolism and summarize the metabolic end products that they generate in their anaerobic habitats, focusing on the biochemical roles that their mitochondria play in anaerobic ATP synthesis. We present metabolic maps of compartmentalized energy metabolism for 16 well-studied species. There are currently no enzymes of core anaerobic energy metabolism that are specific to any of the six eukaryotic supergroup lineages; genes present in one supergroup are also found in at least one other supergroup. The gene distribution across lineages thus reflects the presence of anaerobic energy metabolism in the eukaryote common ancestor and differential loss during the specialization of some lineages to oxic niches, just as oxphos capabilities have been differentially lost in specialization to anoxic niches and the parasitic life-style. Some facultative anaerobes have retained both aerobic and anaerobic pathways. Diversified eukaryotic lineages have retained the same enzymes of anaerobic ATP synthesis, in line with geochemical data indicating low environmental oxygen levels while eukaryotes arose and diversified. PMID:22688819

Müller, Miklós; Mentel, Marek; van Hellemond, Jaap J.; Henze, Katrin; Woehle, Christian; Gould, Sven B.; Yu, Re-Young; van der Giezen, Mark

2012-01-01

329

Photoenhanced anaerobic digestion of organic acids  

DOEpatents

A process is described for rapid conversion of organic acids and alcohols anaerobic digesters into hydrogen and carbon dioxide, the optimal precursor substrates for production of methane. The process includes addition of photosynthetic bacteria to the digester and exposure of the bacteria to radiant energy (e.g., solar energy). The process also increases the pH stability of the digester to prevent failure of the digester. Preferred substrates for photosynthetic bacteria are the organic acid and alcohol waste products of fermentative bacteria. In mixed culture with methanogenic bacteria or in defined co-culture with non-aceticlastic methanogenic bacteria, photosynthetic bacteria are capable of facilitating the conversion or organic acids and alcohols into methane with low levels of light energy input.

Weaver, Paul F. (Golden, CO)

1990-01-01

330

A Comparative Study on Rat Intestinal Epithelial Cells and Resident Gut Bacteria (ii) Effect of Arsenite  

Microsoft Academic Search

Objective In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken. Methods in vitro growth rate of four gut bacteria, dehydrogenase (DHA) and esterase (EA) activity test, intestinal epithelial and bacterial cell membrane enzymes and

RAJ K. UPRETI; A. KANNAN; RICHA SHRIVASTAVA; U. C. CHATURVEDI

2006-01-01

331

Antibacterial activity of medicinal plant extracts against periodontopathic bacteria.  

PubMed

This study was performed to evaluate the antibacterial activity of Althaea officinalis L. roots, Arnica montana L. flowers, Calendula officinalis L. flowers, Hamamelis virginiana L. leaves, Illicium verum Hook. fruits and Melissa officinalis L. leaves, against anaerobic and facultative aerobic periodontal bacteria: Porphyromonas gingivalis, Prevotella spp., Fusobacterium nucleatum, Capnocytophaga gingivalis, Veilonella parvula, Eikenella corrodens, Peptostreptococcus micros and Actinomyces odontolyticus. The methanol extracts of H. virginiana and A. montana and, to a lesser extent, A. officinalis were shown to possess an inhibiting activity (MIC < or = 2048 mg/L) against many of the species tested. In comparison, M. officinalis and C. officinalis extracts had a lower inhibiting activity (MIC > or = 2048 mg/L) against all the tested species with the exception of Prevotella sp. Illicium verum methanol extract was not very active though it had a particular good activity against E. corrodens. The results suggest the use of the alcohol extracts of H. virginiana, A. montana and A. officinalis for topical medications in periodontal prophylactics. PMID:12820224

Iauk, L; Lo Bue, A M; Milazzo, I; Rapisarda, A; Blandino, G

2003-06-01

332

Activity of spectinomycin against anaerobes.  

PubMed

The in vitro inhibitory activity of spectinomycin was tested against various anaerobic bacteria. Different results were obtained with different media and with different initial pH's of the media. The highest minimum inhibitory concentrations for Bacteroides fragilis ([Formula: see text] 128 mug/ml) were obtained with the use of Wilkins-Chalgren agar (pH 7.2) and Brucella blood agar (pH 7.0). Brucella blood agar at higher pH's (7.4 and 8.0) and Mueller-Hinton and Diagnostic Sensitivity Test agars produced lower minimum inhibitory concentrations (32 and 64 mug/ml). This same relationship between spectinomycin activity and pH of the medium was, in general, observed with these media and other anaerobes, including isolates of B. melaninogenicus, Fusobacterium, gram-positive cocci, Clostridium perfringens, and C. ramosum. The variable results observed in this study and in two others make it difficult to predict the clinical usefulness of spectinomycin in the treatment of anaerobic infections. It is probably most appropriate to be guided by results obtained with Wilkins-Chalgren agar and the method proposed as a reference to the National Committee for Clinical Laboratory Standards. These results indicate that spectinomycin is not a potent inhibitor of B. fragilis or other clinically significant anaerobes. PMID:18985

Rosenblatt, J E; Gerdts, A M

1977-07-01

333

Evaluation of the Oxyrase OxyPlate Anaerobe Incubation System  

PubMed Central

The Oxyrase OxyPlate anaerobe incubation system was evaluated for its ability to support the growth of clinically significant anaerobic bacteria previously identified by the Anaerobe Reference Laboratory at the Centers for Disease Control and Prevention. The results were compared with those obtained with conventional anaerobe blood agar plates incubated in an anaerobe chamber. We tested 251 anaerobic bacterial strains. Plates were read at 24, 48, and 72 h; growth was scored by a numerical coding system that combines the degree of growth and the colony size. Organisms (number of strains tested) used in this study were Actinomyces (32), Anaerobiospirillum (8), Bacteroides (39), Campylobacter (8), Clostridium (96), Fusobacterium (12), Leptotrichia (8), Mobiluncus (8), Peptostreptococcus (16), and Propionibacterium (24). At 24 h, 101 (40.2%) of the 251 strains tested showed better growth with the anaerobe chamber than with the OxyPlate system, 10 (4.1%) showed better growth with the OxyPlate system, and the remaining 140 (55.8%) showed equal growth with both systems. At 48 h, 173 (68.9%) showed equal growth with both systems, while 78 (31.1%) showed better growth with the anaerobe chamber. At 72 h, 176 (70.1%) showed equal growth with both systems, while 75 (29.9%) showed better growth with the anaerobe chamber. The OxyPlate system performed well for the most commonly isolated anaerobes but was inadequate for some strains. These results indicate that the Oxyrase OxyPlate system was effective in creating an anaerobic atmosphere and supporting the growth of anaerobic bacteria within 72 h. OxyPlates would be a useful addition to the clinical microbiology laboratory lacking resources for traditional anaerobic culturing techniques. PMID:10655335

Wiggs, Lois S.; Cavallaro, Joseph J.; Miller, J. Michael

2000-01-01

334

Aerobic and anaerobic microbiology of infection after trauma  

Microsoft Academic Search

Clinical and laboratory data from 1973 to 1988 were retrospectively reviewed to study the microbiology of infection following trauma. A total of 368 specimens obtained from 340 trauma patients showed bacterial growth. The traumas included lacerations (163), blunt trauma (76), penetrating trauma (65), bites (20), and open fractures (10). Anaerobic bacteria only were isolated in 119 (32%) specimens, aerobic bacteria

Itzhak Brook; Edith H Frazier

1998-01-01

335

Arnold Schwarzenegger ANAEROBIC DIGESTER  

E-print Network

Arnold Schwarzenegger Governor ANAEROBIC DIGESTER IMPLEMENTATION ISSUES Phase II - A Survey who took concrete steps to install an anaerobic digestion (AD) facility and documentation motivated by being able to reduce odor and use the digested solids as animal bedding. Neither

336

Rapid fluorescence-based measurement of toxicity in anaerobic digestion.  

PubMed

A rapid fluorescence measurement based on resazurin reduction was developed and applied for the detection of toxicants/inhibitors to anaerobic digestion metabolism. By initially using a pure facultative anaerobic strain, Enterococcus faecalis as a model organism, this technique proved to be fast and sensitive when detecting the model toxicant, pentachlorophenol (PCP). The technique revealed significant metabolic changes in Enterococcus faecalis with a PCP spike ranging from 0.05 to 100 mg/L, and could detect PCP's toxicity to E. faecalis at a concentration of only 0.05 mg/L in 8 min. Furthermore, by extending this technique to a mixed anaerobic sludge, not only could the effect of 0.05-100 mg/L PCP be determined on anaerobic digestion metabolism within 10 min, but also its rate of biogas production. These results suggest that a resazurin-based fluorescence measurement can potentially be incorporated into a microfluidic system to develop a biosensor for the real-time monitoring, control and early warning of toxicant/inhibitor loads in the influent to an anaerobic digestion system. PMID:25768985

Chen, Jian Lin; Ortiz, Raphael; Xiao, Yeyuan; Steele, Terry W J; Stuckey, David C

2015-05-15

337

Facultative symbiont infections affect aphid reproduction.  

PubMed

Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum harbors several facultative symbionts influencing several aspects of host ecology. Aphids reproduce by cyclical parthenogenesis whereby clonal and sexual reproduction alternate within the annual life cycle. Many species, including the pea aphid, also show variation in their reproductive mode at the population level, with some lineages reproducing by cyclical parthenogenesis and others by permanent parthenogenesis. While the role of facultative symbionts has been well studied during the parthenogenetic phase of their aphid hosts, very little is known on their possible influence during the sexual phase. Here we investigated whether facultative symbionts modulate the capacity to produce sexual forms in various genetic backgrounds of the pea aphid with controlled symbiont composition and also in different aphid genotypes from natural populations with previously characterized infection status and reproductive mode. We found that most facultative symbionts exhibited detrimental effects on their hosts fitness under sex-inducing conditions in comparison with the reference lines. We also showed that the loss of sexual phase in permanently parthenogenetic lineages of A. pisum was not explained by facultative symbionts. Finally, we demonstrated that Spiroplasma infection annihilated the production of males in the host progeny by inducing a male-killing phenotype, an unexpected result for organisms such as aphids that reproduce primarily through clonal reproduction. PMID:21818272

Simon, Jean-Christophe; Boutin, Sébastien; Tsuchida, Tsutomu; Koga, Ryuichi; Le Gallic, Jean-François; Frantz, Adrien; Outreman, Yannick; Fukatsu, Takema

2011-01-01

338

Microbial and Physicochemical Characteristics of Compact Anaerobic Ammonium-Oxidizing Granules in an Upflow Anaerobic Sludge Blanket Reactor ?  

PubMed Central

Anaerobic ammonium oxidation (anammox) is a promising new process to treat high-strength nitrogenous wastewater. Due to the low growth rate of anaerobic ammonium-oxidizing bacteria, efficient biomass retention is essential for reactor operation. Therefore, we studied the settling ability and community composition of the anaerobic ammonium-oxidizing granules, which were cultivated in an upflow anaerobic sludge blanket (UASB) reactor seeded with aerobic granules. With this seed, the start-up period was less than 160 days at a NH4+-N removal efficiency of 94% and a loading rate of 0.064 kg N per kg volatile suspended solids per day. The formed granules were bright red and had a high settling velocity (41 to 79 m h?1). Cells and extracellular polymeric substances were evenly distributed over the anaerobic ammonium-oxidizing granules. The high percentage of anaerobic ammonium-oxidizing bacteria in the granules could be visualized by fluorescent in situ hybridization and electron microscopy. The copy numbers of 16S rRNA genes of anaerobic ammonium-oxidizing bacteria in the granules were determined to be 4.6 × 108 copies ml?1. The results of this study could be used for a better design, shorter start-up time, and more stable operation of anammox systems for the treatment of nitrogen-rich wastewaters. PMID:20190088

Ni, Bing-Jie; Hu, Bao-Lan; Fang, Fang; Xie, Wen-Ming; Kartal, Boran; Liu, Xian-Wei; Sheng, Guo-Ping; Jetten, Mike; Zheng, Ping; Yu, Han-Qing

2010-01-01

339

Analysis of Transcription of the Staphylococcus aureus Aerobic Class Ib and Anaerobic Class III Ribonucleotide Reductase Genes in Response to Oxygen  

Microsoft Academic Search

Staphylococcus aureus is a gram-positive facultative aerobe that can grow in the absence of oxygen by fermentation or by using an alternative electron acceptor. To investigate the mechanism by which S. aureus is able to adapt to changes in oxygen concentration, we analyzed the transcriptional regulation of genes that encode the aerobic class Ib and anaerobic class III ribonucleotide reductase

MAHMUD MASALHA; ILYA BOROVOK; RACHEL SCHREIBER; YAIR AHARONOWITZ; GERALD COHEN

2001-01-01

340

Culturable heterotrophic bacteria associated with healthy and bleached scleractinian Madracis decactis and the fireworm Hermodice carunculata from the remote St. Peter and St. Paul Archipelago, Brazil.  

PubMed

We report on the first characterization of the culturable heterotrophic bacteria of the scleractinian Madracis decactis. In addition, we characterized the culturable bacteria associated with the fireworm Hermodice carunculata, observed predating partially bleached coral colonies. Our study was carried out in the remote St. Peter and St. Paul Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil. We constituted a 403 isolates collection and subsequently characterized it by means of pyrH and 16S rRNA partial sequences. We identified Photobacterium, Bacillus, and Vibrio species as members of the culturable microbiota of healthy M. decactis. V. campbellii, V. harveyi, V. communis, and V. maritimus were the most commonly found Vibrio species in healthy corals, representing more than 60 % of all vibrio isolates. Most of the vibrios isolated from the fireworm's tissues (n = 143; >90 %) were identified as V. shiloi. However, we did not recover V. shiloi from bleached M. decactis. Instead, we isolated V. communis, a novel Photobacterium species, Bacillus, Kocuria, and Pseudovibrio, suggesting a possible role of other facultative anaerobic bacteria and/or environmental features (such as water quality) in the onset of bleaching in SPSPA's M. decactis. PMID:23979060

Moreira, Ana Paula B; Tonon, Luciane A Chimetto; Pereira, Cecilia do Valle P; Alves, Nelson; Amado-Filho, Gilberto M; Francini-Filho, Ronaldo Bastos; Paranhos, Rodolfo; Thompson, Fabiano L

2014-01-01

341

Evolution and Diversity of Clonal Bacteria: The Paradigm of Mycobacterium tuberculosis  

E-print Network

Evolution and Diversity of Clonal Bacteria: The Paradigm of Mycobacterium tuberculosis Tiago Dos, Faculte´ de Me´dicine, Universite´ Paris V, Paris, France Background. Mycobacterium tuberculosis complex Bacteria: The Paradigm of Mycobacterium tuberculosis. PLoS ONE 3(2): e1538. doi:10.1371/journal

Paris-Sud XI, Université de

342

Symbiosis of methanogenic bacteria and sapropelic protozoa  

Microsoft Academic Search

Fluorescent bacteria were demonstrated to be abundantly spread as single cells throughout the cytoplasm of the giant amoeba Pelomyxa palustris, the sapropelic ciliate Metopus striatus and six other anaerobic protozoa examined. The endosymbionts of P. palustris and M. striatus were identified as methanogenic bacteria on the basis of the presence of the deazaflavin coenzyme F420 and the pterin compound F342.

Johan J. A. van Bruggen; Claudius K. Stumm; Godfried D. Vogels

1983-01-01

343

Spore-Forming Bacteria that Resist Sterilization  

NASA Technical Reports Server (NTRS)

A report presents a phenotypic and genotypic characterization of a bacterial species that has been found to be of the genus Bacillus and has been tentatively named B. odysseensis because it was isolated from surfaces of the Mars Odyssey spacecraft as part of continuing research on techniques for sterilizing spacecraft to prevent contamination of remote planets by terrestrial species. B. odysseensis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium that forms round spores. The exosporium has been conjectured to play a role in the elevated resistance to sterilization. Research on the exosporium is proposed as a path toward improved means of sterilization, medical treatment, and prevention of biofouling.

LaDuc, Myron; Venkateswaran, Kasthuri

2003-01-01

344

Atmospheric vs. anaerobic processing of metabolome samples for the metabolite profiling of a strict anaerobic bacterium, Clostridium acetobutylicum.  

PubMed

Well-established metabolome sample preparation is a prerequisite for reliable metabolomic data. For metabolome sampling of a Gram-positive strict anaerobe, Clostridium acetobutylicum, fast filtration and metabolite extraction with acetonitrile/methanol/water (2:2:1, v/v) at -20°C under anaerobic conditions has been commonly used. This anaerobic metabolite processing method is laborious and time-consuming since it is conducted in an anaerobic chamber. Also, there have not been any systematic method evaluation and development of metabolome sample preparation for strict anaerobes and Gram-positive bacteria. In this study, metabolome sampling and extraction methods were rigorously evaluated and optimized for C. acetobutylicum by using gas chromatography/time-of-flight mass spectrometry-based metabolomics, in which a total of 116 metabolites were identified. When comparing the atmospheric (i.e., in air) and anaerobic (i.e., in an anaerobic chamber) processing of metabolome sample preparation, there was no significant difference in the quality and quantity of the metabolomic data. For metabolite extraction, pure methanol at -20°C was a better solvent than acetonitrile/methanol/water (2:2:1, v/v/v) at -20°C that is frequently used for C. acetobutylicum, and metabolite profiles were significantly different depending on extraction solvents. This is the first evaluation of metabolite sample preparation under aerobic processing conditions for an anaerobe. This method could be applied conveniently, efficiently, and reliably to metabolome analysis for strict anaerobes in air. PMID:24942337

Lee, Sang-Hyun; Kim, Sooah; Kwon, Min-A; Jung, Young Hoon; Shin, Yong-An; Kim, Kyoung Heon

2014-12-01

345

Aerobic and Anaerobic Bacteriology of Cervical Adenitis in Children  

Microsoft Academic Search

Needle aspirates from 53 inflamed cervical lymph glands were studied for aerobic and anaerobic bacteria and mycobacteria. Bacterial growth was achieved in 45 patients (85%). Sixty-six bacterial isolates were recovered, aver aging 1.5 isolates per specimen (0.8 aerobes and 0.7 anaerobes), with as many as 4 isolates in some specimens. Aerobic organisms alone were recovered in 27 aspirates (60%) of

Itzhak Brook

1980-01-01

346

Facultative hyperaccumulation of heavy metals and metalloids.  

PubMed

Approximately 500 species of plants are known to hyperaccumulate heavy metals and metalloids. The majority are obligate metallophytes, species that are restricted to metalliferous soils. However, a smaller but increasing list of plants are "facultative hyperaccumulators" that hyperaccumulate heavy metals when occurring on metalliferous soils, yet also occur commonly on normal, non-metalliferous soils. This paper reviews the biology of facultative hyperaccumulators and the opportunities they provide for ecological and evolutionary research. The existence of facultative hyperaccumulator populations across a wide edaphic range allows intraspecific comparisons of tolerance and uptake physiology. This approach has been used to study zinc and cadmium hyperaccumulation by Noccaea (Thlaspi) caerulescens and Arabidopsis halleri, and it will be instructive to make similar comparisons on species that are distributed even more abundantly on normal soil. Over 90% of known hyperaccumulators occur on serpentine (ultramafic) soil and accumulate nickel, yet there have paradoxically been few experimental studies of facultative nickel hyperaccumulation. Several hypotheses suggested to explain the evolution of hyperaccumulation seem unlikely when most populations of a species occur on normal soil, where plants cannot hyperaccumulate due to low metal availability. In such species, it may be that hyperaccumulation is an ancestral phylogenetic trait or an anomalous manifestation of physiological mechanisms evolved on normal soils, and may or may not have direct adaptive benefits. PMID:24467891

Pollard, A Joseph; Reeves, Roger D; Baker, Alan J M

2014-03-01

347

UNIVERSITE LIBRE DE BRUXELLES FACULTE DE PHARMACIE  

E-print Network

UNIVERSITE LIBRE DE BRUXELLES FACULTE DE PHARMACIE AGREGATION DE L'ENSEIGNEMENT SUPERIEUR SECTION PHARMACIE Année académique : DECOMPTE DES HEURES DE STAGE (N° 12) Règles générales : Tel qu'indiqué au programme des cours de l'Agrégation de l'Enseignement Secondaire Supérieur ­ Orientation Pharmacie, les

Cerf, Nicolas

348

Glycogen accumulating population and its anaerobic substrate uptake in anaerobic-aerobic activated sludge without biological phosphorus removal  

Microsoft Academic Search

The presence of a glycogen accumulating population and its abilities of substrate uptake and storage in anaerobic-aerobic activated sludge fed with mainly acetate were investigated. Because a low phosphorus\\/carbon feeding ratio (2\\/100, wt\\/wt) was used to suppress the growth of polyphosphate-accumulating bacteria, the sludge exhibited no biological phosphorus removal activity. Still, under anaerobic conditions, acetate, propionate, butyrate, valerate, pyruvate, lactate,

Wen-Tso Liu; Takashi Mino; Kazunori Nakamura; Tomonori Matsuo

1996-01-01

349

Microbiology and physiology of anaerobic fermentations of cellulose  

SciTech Connect

The biochemistry and physiology of four major groups of anaerobic bacteria involved in the conversion of cellulose to methane or chemical feedstocks are examined. Aspects of metabolism which are relevant to the interactions and bioenergetics of consortia are being studied. Properties of the cellulolytic enzyme cluster of Clostridium thermocellum are investigated. Five different hydrogenases have been characterized in detail from anaerobic bacteria. Genes for different hydrogenases are being cloned and sequenced to determine their structural relationships. The role of metal clusters in activation of H{sub 2} is being investigated, as is the structure and role of metal clusters in formate metabolism. The function of formate in the total synthesis of acetate from CO{sub 2} and the role of this primary in anaerobes will be examined as well. Finally, these enzyme studies will be performed on thermophilic bacteria and new, pertinent species will be isolated. 50 refs., 3 figs., 1 tab.

Wiegel, J.

1991-05-01

350

Clostridium difficile: the anaerobe that made the grade.  

PubMed

Unlike other anaerobic bacteria of clinical importance, Clostridium difficile has managed to enter into the realm of public awareness. Following the trail blazed by methicillin-resistant Staphylococcus aureus (MRSA), C. difficile has made the transition from being an obscure anaerobic bacterium, mainly of interest to specialist anaerobic microbiologists, to that of an infamous "superbug" responsible for outbreaks of hospital-acquired infection that commonly result in serious disease and death. This report picks out key moments, particularly in the UK, which tracked the rise in both the public and political awareness of this organism. PMID:22293217

Brazier, Jon S

2012-04-01

351

Anaerobic ponds treatment of starch wastewater: case study in Thailand.  

PubMed

Anaerobic ponds are particularly effective in treating high-strength wastewater containing biodegradable solids as they achieve the dual purpose of particulate settlement and organic removal. Performance of an anaerobic pond system for treatment of starch wastewater containing high organic carbon, biodegradable starch particulate matter and cyanide was assessed under tropical climate conditions. Approximately 5000 m3/d of wastewater from starch industry was treated in a series of anaerobic ponds with a total area of 7.39 ha followed by facultative ponds with an area of 29.11 ha. Overall COD and TSS removal of over 90% and CN removal of 51% was observed. Active biomass obtained from the anaerobic ponds sediments and bulk liquid layer exhibited specific methanogenic activity of 20.7 and 11.3 ml CH4/g VSS d, respectively. The cyanide degradability of sludge at initial cyanide concentration of 10 and 20 mg/l were determined to be 0.43 and 0.84 mg CN-/g VSS d, respectively. A separate settling column experiment with starch wastewater revealed that a settling time of approximately 120 min is sufficient to remove 90-95% of the influent TSS. PMID:15246437

Rajbhandari, B K; Annachhatre, A P

2004-11-01

352

BOGUS BACTERIA...  

NSDL National Science Digital Library

Here are some websites to get you started... Just click on the links and start searching! microbe world- bacteria Bacteria Rule Quiz! Bacteria.... Harmful Bacteria Bacteria Museum Bacteria! Microbes- all sorts of info... When you are finished looking at the sites or when you have enough information concerning bacteria, ask Mrs. Deaton for some books that can give you even more DETAIL!!! *Don\\'t forget to keep track of your information on your I-CHARTS... ...

Mrs. Deaton

2007-01-24

353

Molecular characterization and fermentative hydrogen production of a wild anaerobe in clostridium genus  

Microsoft Academic Search

Anaerobic process of biohydrogen production is developed in this paper. The isolation and identification of high efficient\\u000a biohydrogen production anaerobic bacteria are the important foundations for the fermented biohydrogen production process by\\u000a anaerobic digesting organic wastewater. Taking the physiological and biochemical traits, the morphological characteristics\\u000a and 16S rDNA sequence into consideration, the isolate Rennanqilyf33 is a new species.

Yongfeng Li; Nanqi Ren; Chuanping Yang; Jianzheng Li; Peng Li

2007-01-01

354

Molecular tools to track bacteria responsible for fuel deterioration and microbiologically influenced corrosion.  

PubMed

Investigating the susceptibility of various fuels to anaerobic biodegradation has become complicated with the recognition that the fuels themselves are not sterile. Bacterial DNA could be obtained when various fuels were filtered through a hydrophobic teflon (0.22 ?m) membrane filter. Bacterial 16S rRNA genes from these preparations were PCR amplified, cloned, and the resulting libraries sequenced to identify the fuel-borne bacterial communities. The most common sequence, found in algal- and camelina-based biofuels as well as in ultra-low sulfur diesel (ULSD) and F76 diesel, was similar to that of a Tumebacillus. The next most common sequence was similar to Methylobacterium and was found in the biofuels and ULSD. Higher level phylogenetic groups included representatives of the Firmicutes (Bacillus, Lactobacillus and Streptococcus), several Actinobacteria, Deinococcus-Thermus, Chloroflexi, Cyanobacteria, Bacteroidetes, Alphaproteobacteria (Methylobacterium and Sphingomonadales), Betaproteobacteria (Oxalobacteraceae and Burkholderiales) and Deltaproteobacteria. All of the fuel-associated bacterial sequences, except those obtained from a few facultative microorganisms, were from aerobes and only remotely affiliated with sequences that resulted from anaerobic successional events evident when ULSD was incubated with a coastal seawater and sediment inoculum. Thus, both traditional and alternate fuel formulations harbor a characteristic microflora, but these microorganisms contributed little to the successional patterns that ultimately resulted in fuel decomposition, sulfide formation and metal biocorrosion. The findings illustrate the value of molecular approaches to track the fate of bacteria that might come in contact with fuels and potentially contribute to corrosion problems throughout the energy value chain. PMID:22978494

Suflita, Joseph M; Aktas, Deniz F; Oldham, Athenia L; Perez-Ibarra, Beatriz Monica; Duncan, Kathleen

2012-01-01

355

Arnold Schwarzenegger ANAEROBIC DIGESTER  

E-print Network

Arnold Schwarzenegger Governor ANAEROBIC DIGESTER IMPLEMENTATION ISSUES Phase I - A Survey of U concrete steps to install an anaerobic digestion (AD) facility and documentation of the factors to reduce odor and use the digested solids as animal bedding. Neither of these factors was a motivator

356

Anaerobic thermophilic culture  

DOEpatents

A newly discovered thermophilic anaerobe is described that was isolated in a biologically pure culture and designated Thermoanaerobacter ethanolicus ATCC 3/550. T. Ethanolicus is cultured in aqueous nutrient medium under anaerobic, thermophilic conditions and is used in a novel process for producing ethanol by subjecting carbohydrates, particularly the saccharides, to fermentation action of the new microorganism in a biologically pure culture.

Ljungdahl, Lars G. (Athens, GA); Wiegel, Jurgen K. W. (Gottingen, DE)

1981-01-01

357

1Facult I&C, Claude Petitpierre Javascript -HTML  

E-print Network

Petitpierre Instructions Javascript etiquette: while (true) { . . . continue etiquette . . . if (...) { break etiquette; } } switch (expression) { case 4: . . . break; case 3: . . . break; default: . . . } 6Faculté I

Petitpierre, Claude

358

UNIVERSITE PARIS 5 RENE DESCARTES FACULTE DE MEDECINE  

E-print Network

1 UNIVERSITE PARIS 5 ­ RENE DESCARTES FACULTE DE MEDECINE ECOLE DOCTORALE GC2ID Génetique, Cellules'UNIVERSITE PARIS DESCARTES Discipline: Biologie cellulaire et moléculaire Présentée par CHRISTINECHRISTINE

Paris-Sud XI, Université de

359

Metronidazole: in vitro activity, pharmacology and efficacy in anaerobic bacterial infections.  

PubMed

Metronidazole is a 5-nitroimidazole that has selective activity against anaerobic microorganisms, including bacteria and protozoa. Intravenous metronidazole has recently been approved by the U.S. Food and Drug Administration for the treatment of serious anaerobic bacterial infections. It is usually bactericidal at low concentrations, and its spectrum of activity encompasses almost all anaerobic bacteria and some capnophilic organisms. Anaerobic bacteria known to be resistant to metronidazole include occasional anaerobic cocci, some nonsporulating gram-positive bacilli and propionibacterium. Metronidazole is the most active antimicrobial agent against Bacteroides fragilis, the most resistant of anaerobic bacteria. Kill-curve studies demonstrate that there is a 2 to 5 log decrease in the number of colony forming units of B. fragilis and Clostridium perfringens within one hour. The only well documented metronidazole-resistant strain is a B. fragilis isolated from the normal flora of a patient on long-term metronidazole therapy for Crohn's Disease. Metronidazole resistance in Trichomonas vaginalis has recently been described in a few strains that are able to survive at increased oxygen tensions. Metronidazole has been shown to be efficacious in certain protozoal infections including trichomonal vaginitis, extraintestinal amebiasis, and giardiasis. Clinical studies have shown metronidazole to be efficacious in the therapy of a variety of anaerobic infections, including non-traumatic brain abscesses, intraabdominal sepsis, pelvic suppuration and necrotizing soft tissue infections. There have been disappointing results in the therapy of anaerobic pleuropulmonary infections with a number of superinfections caused by aerobic bacteria. Since metronidazole lacks any activity against aerobic bacteria, it must be combined with other agents, usually aminoglycosides, in the treatment of mixed infections involving anaerobic and aerobic bacteria. PMID:6927601

Tally, F P; Sullivan, C E

1981-01-01

360

Novel Clostridium populations involved in the anaerobic degradation of Microcystis blooms  

Microsoft Academic Search

Understanding the microbial degradation of Microcystis biomass is crucial for determining the ecological consequences of Microcystis blooms in freshwater lakes. The purpose of this study was to identify bacteria involved in the anaerobic degradation of Microcystis blooms. Microcystis scum was anaerobically incubated for 90 days at three temperatures (15 °C, 25 °C and 35 °C). We used terminal restriction fragment

Peng Xing; Liang Guo; Wei Tian; Qinglong L Wu; QL Wu

2011-01-01

361

Structure—biodegradation correlation of polyphenols for Thauera aromatica in anaerobic conditions  

Microsoft Academic Search

The anaerobic degradation of phenolic compounds depends greatly on their molecular structure. We have undertaken a systematic study on several phenol derivatives which are commonly found in industrial waters with the aim of investigating the structure–biodegradation relationship for bacteria in anaerobic conditions. The Thauera aromatica strain was used; this bacterium is able to use phenol as a sole carbon source

A. Dibenedetto; R. M. Lo Noce; M. Narracci; M. Aresta

2006-01-01

362

Saccharomyces cerevisiae live cells stimulate degradation and fermentation of cellulose by the rumen anaerobic  

E-print Network

Saccharomyces cerevisiae live cells stimulate degradation and fermentation of cellulose fermentation patterns and to increase numbers of rumen bacteria, especially cellulolytic species (Wallace and fermentation of cellulose by an anaerobic fungus, Neocallimastix frontalis MCH3, which is particularly

Paris-Sud XI, Université de

363

Contribution of Anaerobic Digesters to Emissions Mitigation and Electricity Generation Under U.S. Climate Policy  

E-print Network

Livestock husbandry in the U.S. significantly contributes to many environmental problems, including the release of methane, a potent greenhouse gas (GHG). Anaerobic digesters (ADs) break down organic wastes using bacteria ...

Zaks, David P. M.

364

ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER  

SciTech Connect

During the production of oil and gas, large amounts of water are brought to the surface and must be disposed of in an environmentally sensitive manner. This is an especially difficult problem in offshore production facilities where space is a major constraint. The chief regulatory criterion for produced water is oil and grease. Most facilities have little trouble meeting this criterion using conventional oil-water separation technologies. However, some operations have significant amounts of naphthenic acids in the water that behave as oil and grease but are not well removed by conventional technologies. Aerobic biological treatment of naphthenic acids in simulated-produced water has been demonstrated by others; however, the system was easily overloaded by the large amounts of low-molecular-weight organic acids often found in produced waters. The objective of this research was to determine the ability of an anaerobic biological system to treat these organic acids in a simulated produced water and to examine the potential for biodegradation of the naphthenic acids in the anaerobic environment. A small fixed-film anaerobic biological reactor was constructed and adapted to treat a simulated produced water. The bioreactor was tubular, with a low-density porous glass packing material. The inocula to the reactor was sediment from a produced-water holding pond from a municipal anaerobic digester and two salt-loving methanogenic bacteria. During start-up, the feed to the reactor contained glucose as well as typical produced-water components. When glucose was used, rapid gas production was observed. However, when glucose was eliminated and the major organic component was acetate, little gas was generated. Methane production from acetate may have been inhibited by the high salt concentrations, by sulfide, or because of the lack, despite seeding, of microbes capable of converting acetate to methane. Toluene, a minor component of the produced water (0.1 g/L) was removed in the reactor. Batch tests were conducted to examine naphthenic acid biodegradability under several conditions. The conditions used were seed from the anaerobic reactor, wetland sediments under aerobic and anaerobic conditions, and a sterile control. The naphthenic acid was from a commercial source isolated from Gulf Coast petroleum as was dosed at 2 mg/mL. The incubations were for 30 days at 30 C. The results showed that the naphthenic acids were not biodegraded under anaerobic conditions, but were degraded under aerobic conditions. Despite poor performance of the anaerobic reactor, it remains likely that anaerobic treatment of acetate, toluene, and, potentially, other produced-water components is feasible.

John R. Gallagher

2001-07-31

365

Mangroves: obligate or facultative halophytes? A review  

Microsoft Academic Search

Salinity plays significant roles in regulating the growth and distribution of mangroves, and the salt tolerance mechanisms\\u000a of mangroves have been the focus of research for several decades. There are contradictory views regarding the relationship\\u000a between mangroves and salt: (1) Mangroves are facultative halophytes, i.e. freshwater is a physiological requirement and salt\\u000a water is an ecological requirement for mangroves because

Wenqing Wang; Zhongzheng Yan; Siyang You; Yihui Zhang; Luzhen Chen; Guanghui Lin

366

Modelling simultaneous anaerobic methane and ammonium removal in a granular sludge reactor.  

PubMed

Anaerobic nitrogen removal technologies offer advantages in terms of energy and cost savings over conventional nitrification-denitrification systems. A mathematical model was constructed to evaluate the influence of process operation on the coexistence of nitrite dependent anaerobic methane oxidizing bacteria (n-damo) and anaerobic ammonium oxidizing bacteria (anammox) in a single granule. The nitrite and methane affinity constants of n-damo bacteria were measured experimentally. The biomass yield of n-damo bacteria was derived from experimental data and a thermodynamic state analysis. Through simulations, it was found that the possible survival of n-damo besides anammox bacteria was sensitive to the nitrite/ammonium influent ratio. If ammonium was supplied in excess, n-damo bacteria were outcompeted. At low biomass concentration, n-damo bacteria lost the competition against anammox bacteria. When the biomass loading closely matched the biomass concentration needed for full nutrient removal, strong substrate competition occurred resulting in oscillating removal rates. The simulation results further reveal that smaller granules enabled higher simultaneous ammonium and methane removal efficiencies. The implementation of simultaneous anaerobic methane and ammonium removal will decrease greenhouse gas emissions, but an economic analysis showed that adding anaerobic methane removal to a partial nitritation/anammox process may increase the aeration costs with over 20%. Finally, some considerations were given regarding the practical implementation of the process. PMID:25697694

Winkler, M-K H; Ettwig, K F; Vannecke, T P W; Stultiens, K; Bogdan, A; Kartal, B; Volcke, E I P

2015-04-15

367

Equations and calculations for fermentations of butyric acid bacteria  

Microsoft Academic Search

Saccharolytic clostridia grow anaerobically on a variety of substrates, can produce a large number of useful prod- uct~,~-~ and thus appear to be very promising bacteria for production of organic chemicals from mono-, oligo-, and polysaccharides. Butyric acid bacteria (clostridia) in par- ticular, can anaerobically ferment a variety of sugars (hex- oses, pentoses, and oligosac~harides )~~~~~ to produce a variety

Eleftherios Terry Papoutsakis

1984-01-01

368

Evaluation of the BBL Crystal Anaerobe identification system.  

PubMed Central

The BBL Crystal Anaerobe (ANR) identification system was evaluated, and the results were compared with those from conventional anaerobic methods. We tested 322 clinically significant anaerobic bacteria according to the manufacturer's instructions. The system identified correctly 286 of 322 (88.8%) of the anaerobic bacteria tested. Of these, 263 of 322 (81.7%) were identified correctly on initial testing and 49 were identified correctly only to the genus level; on repeat testing, 23 of 49 (46.9%) were identified correctly to both the genus and the species levels. A total of 26 (8.5%) were misidentified at the species level, and 10 (3.1%) were not identified. Performance characteristics for individual strains varied. The system correctly identified all tested strains of Campylobacter, Desulfomonas, Desulfovibrio, Leptotrichia, Mobiluncus, Peptostreptococcus, Porphyromonas, Provetella, Propionibacterium, Tisierella, and Veillonella and 36 of 37 (97.3%) Actinomyces strains, 42 of 46 (91.3%) B. fragilis group strains, 79 of 103 (76.7%) Clostridium strains, (however, the system failed to identify any of the 7 C. innocuum and 9 C. tetani strains tested), and 8 of 15 (53.3%) Bacteroides strains. This system was easy to use, did not involve the addition of reagents, and was faster than conventional anaerobic procedures. It would be a useful addition to the anaerobe laboratory of most hospitals. PMID:9399517

Cavallaro, J J; Wiggs, L S; Miller, J M

1997-01-01

369

Diversity of Anaerobic Microbes in Spacecraft Assembly Clean Rooms ? †  

PubMed Central

Although the cultivable and noncultivable microbial diversity of spacecraft assembly clean rooms has been previously documented using conventional and state-of-the-art molecular techniques, the occurrence of obligate anaerobes within these clean rooms is still uncertain. Therefore, anaerobic bacterial communities of three clean-room facilities were analyzed during assembly of the Mars Science Laboratory rover. Anaerobic bacteria were cultured on several media, and DNA was extracted from suitable anaerobic enrichments and examined with conventional 16S rRNA gene clone library, as well as high-density phylogenetic 16S rRNA gene microarray (PhyloChip) technologies. The culture-dependent analyses predominantly showed the presence of clostridial and propionibacterial strains. The 16S rRNA gene sequences retrieved from clone libraries revealed distinct microbial populations associated with each clean-room facility, clustered exclusively within gram-positive organisms. PhyloChip analysis detected a greater microbial diversity, spanning many phyla of bacteria, and provided a deeper insight into the microbial community structure of the clean-room facilities. This study presents an integrated approach for assessing the anaerobic microbial population within clean-room facilities, using both molecular and cultivation-based analyses. The results reveal that highly diverse anaerobic bacterial populations persist in the clean rooms even after the imposition of rigorous maintenance programs and will pose a challenge to planetary protection implementation activities. PMID:20228115

Probst, Alexander; Vaishampayan, Parag; Osman, Shariff; Moissl-Eichinger, Christine; Andersen, Gary L.; Venkateswaran, Kasthuri

2010-01-01

370

Pseudomonas aeruginosa, a facultative pathogen of red palm weevil, Rhynchophorus ferrugineus.  

PubMed

Pseudomonas aeruginosa was identified as a facultative pathogen of red palm weevil. Intra-haemocoelic injection of the pathogen within larvae and pre-pupae was more effective at killing the insects [with a median lethal dose (LD50) of 9×10(2) to 2×10(3) bacteria/insect] than inoculation by force feeding (LD50 of 10(5) to 4×10(5) bacteria/insect) or by wading the insects in a suspension of the pathogen (LD50 of 10(5) to 2×10(5) bacteria/insect). Injection of 3×10(3) bacteria/insect killed 69% of larvae; small larvae were more susceptible (LD50 of 9×10(5) bacteria/larva) than either larger larvae (LD50 of 10(3) bacteria/larva) or pre-pupa. The median time to death of the small larvae following injection of P. aeruginosa was about 6 days but that following force feeding or wading was about 8 days. A secondary invader, Serratia marcescens, had no effect on the pathogenicity of P. aeruginosa but hastened death of larvae by about 3 days. PMID:24415007

Banerjee, A; Dangar, T K

1995-11-01

371

Anaerobic pond treatment of wastewater containing sulphate.  

PubMed

Anaerobic ponds are usually used for treatment of industrial and agricultural wastes which contain high organic matter and sulphate. Competition for substrate between sulphate reducing bacteria and methane producing archaea, and the inhibitory effects of sulphide produced from microbial sulphate reduction reported in the literature varied considerably. In this research, a laboratory scale column-in-series anaerobic pond reactor, consisting of five cylindrical columns of acrylic tubes, was operated to evaluate the effect of COD and sulphate ratio on pond performance treating wastewater containing high organic matter and sulphate from a tapioca starch industry. The result depicted that no adverse effect of COD:SO4 ratios between 5 and 20 on overall COD removal performance of anaerobic pond operated with organic loading rate (OLR) of 150 to 600 g COD/m3d. Sulphate reducing bacteria could out-compete methane producing archaea for the same substrate at COD:SO4 ratio equal to or lower than 5 and OLR greater than 300 g COD/m3d. Sulphide inhibition was not observed on overall performance of pond up to an influent sulphate concentration of 650 mg/L. PMID:17591216

Rajbhandari, B K; Annachhatre, A P

2007-01-01

372

Involvement of periodontopathic anaerobes in aspiration pneumonia.  

PubMed

Increasing evidence has linked the anaerobic bacteria forming periodontopathic biofilms with aspiration pneumonia in elderly persons. In experiments designed to eliminate the potent respiratory pathogens forming biofilms in the oral cavity, we have shown that the mechanical and chemical oral cleansing using povidone-iodine effectively reduced the detection rates and numbers of methicillin-sensitive Staphylococcus species, Streptococcus pneumoniae, and Haemophilus influenzae in patients scheduled to undergo oral surgery requiring endotracheal intubation. We confirmed the pathogenicity of periodontopathic anaerobic bacteria for aspiration pneumonia in an experimental mouse model. Based upon the finding of the coexistence of Porphyromonas gingivalis with Treponema denticola in chronic periodontitis lesions, we innoculated a mixed culture of P. gingivalis and T. denticola into the mouse trachea; the resulting infection induced inflammatory cytokine production and caused pneumonia. In another series of investigations, professional oral health care (POHC), mainly cleansing administered by dental hygienists once a week for 24 months to elderly persons requiring daily care, resulted in the reduction of the number of total anaerobes, Candida albicans, and Staphylococcus species and in the number of cases of fatal aspiration pneumonia. We also found that the POHC treatment of elderly persons for 6 months in the winter season reduced the salivary levels of protease, trypsin-like activity, and neuraminidase and also decreased the frequency of influenza cases. PMID:16277588

Okuda, Katsuji; Kimizuka, Ryuta; Abe, Shu; Kato, Tetsuo; Ishihara, Kazuyuki

2005-11-01

373

Some unique features of alkaliphilic anaerobes  

NASA Astrophysics Data System (ADS)

This article explores two topics involving the examination of four strains of alkaliphilic anaerobes. The first topic was dedicated to detection of the ability of microorganisms to metabolize alternative chirality substrates. Two saccharolytic anaerobic bacteria were chosen for the first experiment: Anaerovirgula multivorans strain SCAT, which is gram positive and spore-forming; and Spirochaeta dissipatitropha, strain ASpC2T, which is gram negative. It was found that both checked sugarlytics were able to use L-ribose and L-arabinose, as growth substrates. The second part was concerned of study a chemolithotrophy in two halo-alkaliphilic sulfate reducing bacteria: Desulfonatornum thiodismutans strain MLF1T and Desulfonatronum lacustre strain Z-7951T. The experiments with lithotrophs had demonstrated that strain MLF1T was capable to grow without any organic source of carbon, while strain Z-7951T had required at least 2 mM sodium acetate for growth. Anaerobic technique was used for preparation of the growth media and maintenance of these bacterial cultures. Standard methods for Gram, spore, and flagella staining were applied for characterization of cytomorphology. In this article, the results of the experiments performed on cytological, physiological, and biochemical levels are presented and discussed.

Roof, Erin; Pikuta, Elena; Otto, Christopher; Williams, George; Hoover, Richard

2013-09-01

374

FACULTATIVE LAGOON EFFLUENT POLISHING USING PHASE ISOLATION PONDS  

EPA Science Inventory

An investigation into the performance of 'Phase Isolation' as a means of upgrading facultative lagoons was conducted at Clinton, Mississippi, using 2 facultative lagoons arranged in series followed by 2 isolation ponds used alternately for final polishing. The isolation ponds wer...

375

Worldwide populations of APHIS CRACCIVORA have diverse facultative bacterial symbionts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Facultative bacterial endosymbionts can play an important role in the evolutionary trajectory of their hosts. Aphids are infected with a wide variety of facultative endosymbionts that can confer ecologically relevant traits, which in turn may drive microevolution in a dynamic selective environment....

376

Characteristics, Process Parameters, and Inner Components of Anaerobic Bioreactors  

PubMed Central

The anaerobic bioreactor applies the principles of biotechnology and microbiology, and nowadays it has been used widely in the wastewater treatment plants due to their high efficiency, low energy use, and green energy generation. Advantages and disadvantages of anaerobic process were shown, and three main characteristics of anaerobic bioreactor (AB), namely, inhomogeneous system, time instability, and space instability were also discussed in this work. For high efficiency of wastewater treatment, the process parameters of anaerobic digestion, such as temperature, pH, Hydraulic retention time (HRT), Organic Loading Rate (OLR), and sludge retention time (SRT) were introduced to take into account the optimum conditions for living, growth, and multiplication of bacteria. The inner components, which can improve SRT, and even enhance mass transfer, were also explained and have been divided into transverse inner components, longitudinal inner components, and biofilm-packing material. At last, the newly developed special inner components were discussed and found more efficient and productive. PMID:24672798

Abdelgadir, Awad; Chen, Xiaoguang; Liu, Jianshe; Xie, Xuehui; Zhang, Jian; Zhang, Kai; Wang, Heng; Liu, Na

2014-01-01

377

Anaerobic degradation of organic compounds at high salt concentrations  

Microsoft Academic Search

A number of obligately anaerobic fermentative bacteria are known to degrade a variety of organic substrates such as sugars, amino acids, and others, in the presence of high salt concentrations (up to 3–4 M) to products such as hydrogen, CO2, acetate and higher fatty acids, and ethanol. Our understanding of the fate of these products in hypersaline environments is still

Aharon Oren

1988-01-01

378

Anaerobic bacterial metabolism in the ancient eukaryote Giardia duodenalis  

Microsoft Academic Search

The protozoan parasite, Giardia duodenalis, shares many metabolic and genetic attributes of the bacteria, including fermentative energy metabolism which relies heavily on pyrophosphate rather than adenosine triphosphate and as a result contains two typically bacterial glycolytic enzymes which are pyrophosphate dependent. Pyruvate decarboxylation and subsequent electron transport to as yet unidentified anaerobic electron acceptors relies on a eubacterial-like pyruvate:ferredoxin oxidoreductase

D. M. Brown; J. A. Upcroft; M. R. Edwards; P. Upcroft

1998-01-01

379

Contamination flows of Bacillus cereus and spore-forming aerobic bacteria in a cooked, pasteurized and chilled zucchini purée processing line  

Microsoft Academic Search

A food processing plant producing pasteurized purées and its zucchini purée processing line were examined for contamination with aerobic and facultative anaerobic bacterial spores during a day's operation. Multiplication of spores was also monitored in the product stored under different conditions. High concentrations of Bacillus cereus spores were found in the soil in which the zucchinis were grown (4.6±0.3 log

M. H Guinebretiere; H Girardin; C Dargaignaratz; F Carlin; C Nguyen-The

2003-01-01

380

Arsenic, Anaerobes, and Astrobiology  

NASA Astrophysics Data System (ADS)

Arsenic is an element best known for its highly poisonous nature, so it is not something one would associate with being a well-spring for life. Yet discoveries made over the past two decades have delineated that not only are some microbes resistant to arsenic, but that this element's primary redox states can be exploited to conserve energy and support prokaryotic growth ('arsenotrophy') in the absence of oxygen. Hence, arsenite [As(III)] can serve as an electron donor for chemo- or photo-autotrophy while arsenate [As(V)] will serve as an electron acceptor for chemo-heterotrophs and chemo-autotrophs. The phylogenetic diversity of these microbes is broad, encompassing many individual species from diverse taxonomic groups in the Domain Bacteria, with fewer representatives in the Domain Archaea. Speculation with regard to the evolutionary origins of the key functional genes in anaerobic arsenic transformations (arrA and arxA) and aerobic oxidation (aioB) has led to a disputation as to which gene and function is the most ancient and whether arsenic metabolism extended back into the Archaean. Regardless of its origin, robust arsenic metabolism has been documented in extreme environments that are rich in their arsenic content, such as hot springs and especially hypersaline soda lakes associated with volcanic regions. Searles Lake, CA is an extreme, salt-saturated end member where vigorous arsenic metabolism occurs, but there is no detectable sulfate-reduction or methanogenesis. The latter processes are too weak bio-energetically to survive as compared with arsenotrophy, and are also highly sensitive to the abundance of borate ions present in these locales. These observations have implications with respect to the search for microbial life elsewhere in the Solar System where volcanic-like processes have been operative. Hence, because of the likelihood of encountering dense brines in the regolith of Mars (formed by evapo-concentration) or beneath the ice layers of Europa, Ganymede, Titan or Enceladus (formed by cryo-concentration), arsenotrophy could serve as a credible means of microbial energy conservation. Regrettably, the direct search for arsenic biomarkers is restricted because only one stable isotope exists (75As), which rules out the use of stable isotopic ratios in this regard. However, antimony oxyanions often co-occur with arsenic in the environment. Its two stable isotopes (123Sb and 121Sb) hold the potential to be exploited as a proxy isotopic biomarker for the fingerprint of microbial arsenotrophy. Whether such an approach is feasible needs to be investigated.

Stolz, J. F.; Oremland, R. S.; Switzer Blum, J.; Hoeft, S. E.; Baesman, S. M.; Bennett, S.; Miller, L. G.; Kulp, T. R.; Saltikov, C.

2013-12-01

381

ANAMMOX process start up and stabilization with an anaerobic seed in Anaerobic Membrane Bioreactor (AnMBR).  

PubMed

ANaerobic AMMonium OXidation (ANAMMOX) process, an advanced biological nitrogen removal alternative to traditional nitrification--denitrification removes ammonia using nitrite as the electron acceptor without oxygen. The feasibility of enriching anammox bacteria from anaerobic seed culture to start up an Anaerobic Membrane Bioreactor (AnMBR) for N-removal is reported in this paper. The Anammox activity was established in the AnMBR with anaerobic digester seed culture from a Sewage Treatment Plant in batch mode with recirculation followed by semi continuous process and continuous modes of operation. The AnMBR performance under varying Nitrogen Loading Rates (NLR) and HRTs is reported for a year, in terms of nitrogen transformations to ammoniacal nitrogen, nitrite and nitrate along with hydrazine and hydroxylamine. Interestingly ANAMMOX process was evident from simultaneous Amm-N and nitrite reduction, consistent nitrate production, hydrazine and hydroxylamine presence, notable organic load reduction and bicarbonate consumption. PMID:21775136

Suneethi, S; Joseph, Kurian

2011-10-01

382

Impact of fertilizing with raw or anaerobically digested sewage sludge on the abundance of antibiotic-resistant coliforms, antibiotic resistance genes, and pathogenic bacteria in soil and on vegetables at harvest.  

PubMed

The consumption of crops fertilized with human waste represents a potential route of exposure to antibiotic-resistant fecal bacteria. The present study evaluated the abundance of bacteria and antibiotic resistance genes by using both culture-dependent and molecular methods. Various vegetables (lettuce, carrots, radish, and tomatoes) were sown into field plots fertilized inorganically or with class B biosolids or untreated municipal sewage sludge and harvested when of marketable quality. Analysis of viable pathogenic bacteria or antibiotic-resistant coliform bacteria by plate counts did not reveal significant treatment effects of fertilization with class B biosolids or untreated sewage sludge on the vegetables. Numerous targeted genes associated with antibiotic resistance and mobile genetic elements were detected by PCR in soil and on vegetables at harvest from plots that received no organic amendment. However, in the season of application, vegetables harvested from plots treated with either material carried gene targets not detected in the absence of amendment. Several gene targets evaluated by using quantitative PCR (qPCR) were considerably more abundant on vegetables harvested from sewage sludge-treated plots than on vegetables from control plots in the season of application, whereas vegetables harvested the following year revealed no treatment effect. Overall, the results of the present study suggest that producing vegetable crops in ground fertilized with human waste without appropriate delay or pretreatment will result in an additional burden of antibiotic resistance genes on harvested crops. Managing human exposure to antibiotic resistance genes carried in human waste must be undertaken through judicious agricultural practice. PMID:25172864

Rahube, Teddie O; Marti, Romain; Scott, Andrew; Tien, Yuan-Ching; Murray, Roger; Sabourin, Lyne; Zhang, Yun; Duenk, Peter; Lapen, David R; Topp, Edward

2014-11-01

383

Bacteria Museum  

NSDL National Science Digital Library

Who knew that bacteria had their own virtual museum? Here, visitors will "learn that not all bacteria are harmful, how they are used in industry, that they belong to the oldest living creatures on Earth", and many more interesting facts to discover about the diverse world of bacteria. The "Bacterial Species Files" tab at the top of the page, allows visitors to look up information on 40 different specific bacteria, from Anthrax to Yersinia enterocolitica. The information provided for each bacterium includes photographs, consumer guides, fact sheets, and scientific links. Visitors will find that the "Main Exhibits" tab addresses the basics about bacteria, as well as "Pathogenic Bacteria", "Evolution", "How We Fight Bacteria", and "Food and Water Safety". Visitors will surely enjoy the "Good Bacteria in Food" link found in the Food and Water Safety section, as it explains how some foods benefit from good bacteria, such as Swiss cheese, sausage, sauerkraut, chocolate, and coffee.

384

The microbiology and physiology of anaerobic fermentations of cellulose: Progress report, November 1988--July 1989  

SciTech Connect

In this progress report we describe an integrated study of some individual anaerobic bacteria that are important for the complete conversion of cellulose to methane and CO/sub 2/, and of enzymes such as formate dehydrogenase, hydrogenase and CO dehydrogenase which are of special concern to syntropic interactions between the bacteria.

Peck, H.D. Jr.; Ljungdahl, L.G.; Mortenson, L.E.; Wiegel, J.K.W.

1989-01-01

385

Microbial decolorization of reactive black-5 in a two-stage anaerobic–aerobic reactor using acclimatized activated textile sludge  

Microsoft Academic Search

A two-stage anaerobic–aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent was used to degrade reactive black 5 dye (RB-5). The anaerobic step was studied in more detail by varying the dye concentration from 100 to 3000 mg l?1. The results showed that major decolorization was achieved during the anaerobic process. The time required for decolorization by

Sagarika Mohanty; Nishant Dafale; Nageswara Neti Rao

2006-01-01

386

Bacteriology of chronic otitis media affecting children living in Rio de Janeiro.  

PubMed

A bacteriologic analysis was performed on the purulent exudates obtained from the middle ears of 45 children living in Rio de Janeiro with CSOM and spontaneous perforations of the ear drum. Anaerobic cultures showed anaerobic bacteria in association with aerobic or facultatively anaerobic bacteria, or both, in 30 (66.7%) specimens. Facultative anaerobic microorganisms occurred in 42 (93.3%) of the specimens analyzed, strict aerobes in 17 (37.8%), capnophilic in 6 (13.3%), and fungi in 4 (8.9%). The rate of different species of bacteria isolated per sample was 4.4:1.87 for anaerobic and 1.84 for facultative microorganisms. Multiple drug resistances in the aerobic and facultative bacteria were found, and tetracycline, erythromycin, and beta-lactam antibiotic resistances were accentuated in the anaerobic bacteria. PMID:2663439

de Uzeda, M; Rocha, E R

1989-06-01

387

Two Host Clades, Two Bacterial Arsenals: Evolution through Gene Losses in Facultative Endosymbionts.  

PubMed

Bacterial endosymbiosis is an important evolutionary process in insects, which can harbor both obligate and facultative symbionts. The evolution of these symbionts is driven by evolutionary convergence, and they exhibit among the tiniest genomes in prokaryotes. The large host spectrum of facultative symbionts and the high diversity of strategies they use to infect new hosts probably impact the evolution of their genome and explain why they undergo less severe genomic erosion than obligate symbionts. Candidatus Hamiltonella defensa is suitable for the investigation of the genomic evolution of facultative symbionts because the bacteria are engaged in specific relationships in two clades of insects. In aphids, H. defensa is found in several species with an intermediate prevalence and confers protection against parasitoids. In whiteflies, H. defensa is almost fixed in some species of Bemisia tabaci, which suggests an important role of and a transition toward obligate symbiosis. In this study, comparisons of the genome of H. defensa present in two B. tabaci species (Middle East Asia Minor 1 and Mediterranean) and in the aphid Acyrthosiphon pisum revealed that they belong to two distinct clades and underwent specific gene losses. In aphids, it contains highly virulent factors that could allow protection and horizontal transfers. In whiteflies, the genome lost these factors and seems to have a limited ability to acquire genes. However it contains genes that could be involved in the production of essential nutrients, which is consistent with a primordial role for this symbiont. In conclusion, although both lineages of H. defensa have mutualistic interactions with their hosts, their genomes follow distinct evolutionary trajectories that reflect their phenotype and could have important consequences on their evolvability. PMID:25714744

Rollat-Farnier, Pierre-Antoine; Santos-Garcia, Diego; Rao, Qiong; Sagot, Marie-France; Silva, Francisco J; Henri, Hélène; Zchori-Fein, Einat; Latorre, Amparo; Moya, Andrés; Barbe, Valérie; Liu, Shu-Sheng; Wang, Xiao-Wei; Vavre, Fabrice; Mouton, Laurence

2015-01-01

388

THERMOPHILIC ANAEROBIC BIODEGRADATION OF PHENOLICS  

EPA Science Inventory

The report gives results of a series of anaerobic microbial acclimation and treatment performance tests with synthetic phenolic substrates. The research is a feasibility level assessment of substituting anaerobic biodegradation of phenolics for solvent extraction. The tests showe...

389

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

390

Phenotypic and Genotypic Characterization of Lactic Acid Bacteria Isolated from Some Nigerian Traditional Fermented Foods  

Microsoft Academic Search

A total of 104 lactic acid bacteria were isolated from ogi, wara, fermenting cassava mash for local food product gari and raw milk for nono. They were characterized phenotypically and divided into six main groups, which are facultative heterofermentative rods, obligate heterofermentative rods, tetrad-forming homofermentative cocci, homofermentative cocci, heterofermentative cocci, and an unidentified group. A total of 40 strains with

Kolawole Banwo; Abiodun Sanni; Huarong Tan; Yuqing Tian

2012-01-01

391

Utilization of cathodic hydrogen by hydrogen-oxidizing bacteria  

Microsoft Academic Search

Hydrogen is consumed by methanogenic, sulphate-reducing, and homoacetogenic bacteria and members of these bacterial groups are able to grow chemolithotrophically with hydrogen as sole energy source. Cathodic hydrogen consumption by sulphate-reducing bacteria has been proposed as one of the factors in the anaerobic corrosion of metals. Desulfovibrio spp. were able to utilize cathodic hydrogen from mild steel as the only

B. S. Rajagopal; J. LeGall

1989-01-01

392

ACETOGENIC BACTERIA ASSOCIATED WITH SEAGRASS ROOTS  

EPA Science Inventory

Seagrasses are adapted to being rooted in reduced, anoxic sediments with high rates of sulfate reduction. During the day, an oxygen gradient is generated around the roots, becoming anoxic at night. Thus, obligate anaerobic bacteria in the rhizosphere have to tolerate elevated oxy...

393

Sensitivity analysis and parameter estimation in a model of anaerobic waste water treatment processes with substrate inhibition  

Microsoft Academic Search

Anaerobic waste water treatment processes are commonly presented by the fifth order Hill and Barth non-linear model, describing three main stages of anaerobic digestion. The model investigated in the present work is a modified version of the Hill and Barth model, which includes substrate inhibition of growth of methanogenic bacteria. Parameter estimation of this model is a difficult problem because

N. A. Noykova; M. Gyllenberg

2000-01-01

394

Comparative Evaluation of Anaerobic Bacterial Communities Associated with Roots of Submerged Macrophytes Growing in Marine or Brackish Water Sediments  

EPA Science Inventory

Sediment microbial communities are important for seagrass growth and carbon cycling, however relatively few studies have addressed the composition of prokaryotic communities in seagrass bed sediments. Selective media were used enumerate culturable anaerobic bacteria associated ...

395

Anaerobic treatment of effluents from an industrial polymers synthesis plant  

SciTech Connect

The feasibility of the anaerobic treatment of an industrial polymer synthesis plant effluent was evaluated. The composition of the wastewater includes acrylates, styrene, detergents, a minor amount of silicates and a significant amount of ferric chloride. The average chemical oxygen demand (COD) corresponding is about 2,000 mg/l. The anaerobic biodegradability of the effluent is shown and the toxicity effect on the populations of anaerobic bacteria is evaluated. The results of the anaerobic biodegradation assays show that 62% of the wastewater compounds, measured as COD, could be consumed. An upflow anaerobic sludge blanket (UASB) reactor was used in the evaluation, it has a diameter-height ratio of 1:7, and 4-liter volume. The inoculum was obtained from a UASB pilot plant that treats brewery wastewaters. At the beginning of the operation, the biomass showed an anaerobic activity of 0.58 gCOD/(gVSS {times} d), it decreased only 2.5% in the subsequent 4 months. After 35 days