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isolation and characterization of a sulfate-reducing bacterium that anaerobically degrades alkanes.an alkane-degrading, sulfate-reducing bacterial strain, ak-01, was isolated from an estuarine sediment with a history of chronic petroleum contamination. the bacterium is a short, nonmotile, non-spore-forming, gram-negative rod. it is mesophilic and grows optimally at ph 6.9 to 7.0 and at an nacl concentration of 1%. formate, fatty acids (c4 to c16) and hydrogen were readily utilized as electron donors. sulfate, sulfite, and thiosulfate were used as electron acceptors, but sulfur, nitrite, and n ...199910388691
biogeochemical and molecular signatures of anaerobic methane oxidation in a marine sediment.anaerobic methane oxidation was investigated in 6-m-long cores of marine sediment from aarhus bay, denmark. measured concentration profiles for methane and sulfate, as well as in situ rates determined with isotope tracers, indicated that there was a narrow zone of anaerobic methane oxidation about 150 cm below the sediment surface. methane could account for 52% of the electron donor requirement for the peak sulfate reduction rate detected in the sulfate-methane transition zone. molecular signatu ...200111282617
comparative analysis of methane-oxidizing archaea and sulfate-reducing bacteria in anoxic marine sediments.the oxidation of methane in anoxic marine sediments is thought to be mediated by a consortium of methane-consuming archaea and sulfate-reducing bacteria. in this study, we compared results of rrna gene (rdna) surveys and lipid analyses of archaea and bacteria associated with methane seep sediments from several different sites on the californian continental margin. two distinct archaeal lineages (anme-1 and anme-2), peripherally related to the order methanosarcinales, were consistently associated ...200111282650
bacterial diversity and sulfur cycling in a mesophilic sulfide-rich spring.an artesian sulfide- and sulfur-rich spring in southwestern oklahoma is shown to sustain an extremely rich and diverse microbial community. laboratory incubations and autoradiography studies indicated that active sulfur cycling is occurring in the abundant microbial mats at zodletone spring. anoxygenic phototrophic bacteria oxidize sulfide to sulfate, which is reduced by sulfate-reducing bacterial populations. the microbial community at zodletone spring was analyzed by cloning and sequencing 16s ...200312957951
high overall diversity and dominance of microdiverse relationships in salt marsh sulphate-reducing bacteria.the biogeochemistry of north atlantic salt marshes is characterized by the interplay between the marsh grass spartina and sulphate-reducing bacteria (srb), which mineralize the diverse carbon substrates provided by the plants. it was hypothesized that srb populations display high diversity within the sediment as a result of the rich spatial and chemical structuring provided by spartina roots. a 2000-member 16s rrna gene library, prepared with delta-proteobacterial srb-selective primers, was anal ...200415186347
membrane lipid patterns typify distinct anaerobic methanotrophic consortia.the anaerobic oxidation of methane (aom) is one of the major sinks of this substantial greenhouse gas in marine environments. recent investigations have shown that diverse communities of anaerobic archaea and sulfate-reducing bacteria are involved in aom. most of the relevant archaea are assigned to two distinct phylogenetic clusters, anme-1 and anme-2. a suite of specific (13)c-depleted lipids demonstrating the presence of consortia mediating aom in fossil and recent environments has been estab ...200415258285
polyhydroxyalkanoate (pha) accumulation in sulfate-reducing bacteria and identification of a class iii pha synthase (phaec) in desulfococcus multivorans.seven strains of sulfate-reducing bacteria (srb) were tested for the accumulation of polyhydroxyalkanoates (phas). during growth with benzoate desulfonema magnum accumulated large amounts of poly(3-hydroxybutyrate) [poly(3hb)]. desulfosarcina variabilis (during growth with benzoate), desulfobotulus sapovorans (during growth with caproate), and desulfobacterium autotrophicum (during growth with caproate) accumulated poly(3hb) that accounted for 20 to 43% of cell dry matter. desulfobotulus sapovor ...200415294771
cadmium accumulation and dna homology with metal resistance genes in sulfate-reducing bacteria.cadmium resistance (0.1 to 1.0 mm) was studied in four pure and one mixed culture of sulfate-reducing bacteria (srb). the growth of the bacteria was monitored with respect to carbon source (lactate) oxidation and sulfate reduction in the presence of various concentrations of cadmium chloride. two strains desulfovibrio desulfuricans dsm 1926 and desulfococcus multivorans dsm 2059 showed the highest resistance to cadmium (0.5 mm). transmission electron microscopy of the two strains showed intracel ...200516085855
microbial community structure of sandy intertidal sediments in the north sea, sylt-rømø basin, wadden sea.molecular biological methods were used to investigate the microbial diversity and community structure in intertidal sandy sediments near the island of sylt (wadden sea) at a site which was characterized for transport and mineralization rates in a parallel study (d. de beer, f. wenzhöfer, t. ferdelman, s.e. boehme, m. huettel, j.e.e. van beusekom, m.e. böttcher, n. musat, n. dubilier, transport and mineralization rates in north sea sandy intertidal sediments, sylt-romo basin, wadden sea, limnol. ...200616431068
exposure to sulfide causes populations shifts in sulfate-reducing consortia.the shift in the community structure of a mixed culture of sulfate-reducing bacteria (srb) at 0.5, 0.75, 1, and 1.5 kg m(-3) sulfide loadings was investigated in an anaerobic continuous bioreactor used for treatment of sulfate-containing wastewater by fluorescence in situ hybridization (fish), using srb species-specific and group-specific 16s rrna-targeting probes. hybridization analysis using these 16s rrna-targeted oligonucleotide probes revealed that sulfide was toxic for desulfonema, desulfo ...200616814989
sulfate-reducing bacteria methylate mercury at variable rates in pure culture and in marine sediments.differences in methylmercury (ch(3)hg) production normalized to the sulfate reduction rate (srr) in various species of sulfate-reducing bacteria (srb) were quantified in pure cultures and in marine sediment slurries in order to determine if srb strains which differ phylogenetically methylate mercury (hg) at similar rates. cultures representing five genera of the srb (desulfovibrio desulfuricans, desulfobulbus propionicus, desulfococcus multivorans, desulfobacter sp. strain bg-8, and desulfobacte ...200010831421
extracellular metal-binding activity of the sulphate-reducing bacterium desulfococcus multivorans.polarography was used to measure the copper-binding ability of culture filtrates from a range of sulphate-reducing bacteria (srb), including pure cultures and environmental isolates. of those tested, desulfococcus multivorans was shown to have the greatest copper-binding capacity and this organism was used for further experiments. extracellular copper- and zinc-binding activities of dc. multivorans culture filtrates from batch cultures increased over time and reached a maximum after 10 d growth. ...199910537221
seasonal changes in the relative abundance of uncultivated sulfate-reducing bacteria in a salt marsh sediment and in the rhizosphere of spartina alterniflora.phylogenetic diversity and community composition of sulfate-reducing bacteria in a salt marsh sediment and in the rhizosphere of spartina alterniflora were investigated. uncultivated desulfobacteriaceae family-related phylotypes were studied by selectively amplifying 16s rrna gene fragments from dna extracted from salt marsh rhizosphere samples. two novel phylotypes were retrieved from rhizosphere samples, with a01 having 89.1% sequence similarity with desulfococcus multivorans and 4d19 having 9 ...19979327553
identification of population dynamics in sulfate-reducing consortia on exposure to sulfate.the microbial population structure and function of a mixed culture of sulfate-reducing bacteria (srb) maintained in anaerobic continuous bioreactors were tracked before and after a major perturbation, which involved the addition of sulfate to the influent of a bioreactor when operated at steady state at 35 degrees c, ph 7.8 and a 2.5 day residence time with feed stream containing 10 and 15 kg m(-3) sulfate as terminal electron acceptor and 19.6 and 29.4 kg m(-3) ethanol as carbon source and elec ...200617008063
diversity and origin of desulfovibrio species: phylogenetic definition of a family.the different nutritional properties of several desulfovibrio desulfuricans strains suggest that either the strains are misclassified or there is a high degree of phenotypic diversity within the genus desulfovibrio. the results of partial 16s rrna and 23s rrna sequence determinations demonstrated that desulfovibrio desulfuricans atcc 27774 and "desulfovibrio multispirans" are closely related to the type strain (strain essex 6) and that strains atcc 7757, norway 4, and el agheila z are not. there ...19902361938
sulfate-reducing bacteria in tubes constructed by the marine infaunal polychaete diopatra cuprea.marine infaunal burrows and tubes greatly enhance solute transport between sediments and the overlying water column and are sites of elevated microbial activity. biotic and abiotic controls of the compositions and activities of burrow and tube microbial communities are poorly understood. the microbial communities in tubes of the marine infaunal polychaete diopatria cuprea collected from two different sediment habitats were examined. the bacterial communities in the tubes from a sandy sediment di ...200415574900
anaerobic biodegradation of tce in laboratory columns of fractured saprolite.an experiment was conducted to determine if biodegradation of trichloroethylene (tce) can occur in previously uncontaminated ground water in saturated fractured saprolite (highly weathered material derived from sedimentary rocks). two undisturbed columns (0.23 m diameter by 0.25 m long) of fractured saprolite were collected from approximately 2 m depth at an uncontaminated site on the oak ridge reservation, oak ridge, tennessee. natural, uncontaminated ground water from the site, which was degas ...200415318776
anaerobic oxidation of o-xylene, m-xylene, and homologous alkylbenzenes by new types of sulfate-reducing bacteria.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 delta subcl ...199910049854
catabolic and anabolic enzyme activities and energetics of acetone metabolism of the sulfate-reducing bacterium desulfococcus biacutus.acetone degradation by cell suspensions of desulfococcus biacutus was co2 dependent, indicating initiation by a carboxylation reaction, while degradation of 3-hydroxybutyrate was not co2 dependent. growth on 3-hydroxybutyrate resulted in acetate accumulation in the medium at a ratio of 1 mol of acetate per mol of substrate degraded. in acetone-grown cultures no coenzyme a (coa) transferase or coa ligase appeared to be involved in acetone metabolism, and no acetate accumulated in the medium, sugg ...19957814315
natural relationships among sulfate-reducing eubacteria.phylogenetic relationships among 20 nonsporeforming and two endospore-forming species of sulfate-reducing eubacteria were inferred from comparative 16s rrna sequencing. all genera of mesophilic sulfate-reducing eubacteria except the new genus desulfomicrobium and the gliding desulfonema species were included. the sporeforming species desulfotomaculum ruminis and desulfotomaculum orientis were found to be gram-positive organisms sharing 83% 16s rrna sequence similarity, indicating that this genus ...19892480344
anaerobic degradation of acetone by desulfococcus biacutus spec. nov.from anaerobic digestor sludge of a waste water treatment plant, a gram-negative, strictly anaerobic sulfate-reducing bacterium was isolated with acetone as sole organic substrate. the bacterium was characterized as a new species, desulfococcus biacutus. the strain grew with acetone with doubling times of 72 h to 120 h; the growth yield was 12.0 (+/- 2.1) g x [mol acetone]-1. acetone was oxidized completely, and no isopropanol was formed. in labelling studies with 14co2, cell lipids (including a ...19902244787
competition and coexistence of sulfate-reducing and methanogenic populations in anaerobic biofilms.the microbial population structure and function of natural anaerobic communities maintained in laboratory fixed-bed biofilm reactors were tracked before and after a major perturbation, which involved the addition of sulfate to the influent of a reactor that had previously been fed only glucose (methanogenic), while sulfate was withheld from a reactor that had been fed both glucose and sulfate (sulfidogenic). the population structure, determined by using phylogenetically based oligonucleotide pro ...199616535428
cometabolic transformation and cleavage of nitrodiphenylamines by three newly isolated sulfate-reducing bacterial strains.three sulfate-reducing bacterial strains (desulfovibrio sp. strain shv, desulfococcus sp. strain whc, and desulfomicrobium sp. strain whb) with the capacity to cometabolize 2-nitrodiphenylamine, 4-nitrodiphenylamine, and 2,4-dinitrodiphenylamine were newly isolated. before breaking down the diphenylamine structure, these strains cometabolically reduce the nitrodiphenylamines to the corresponding aminodiphenylamines during anaerobic oxidation of the growth substrate lactate (desulfovibrio strain ...199616535317
structure of sediment-associated microbial communities along a heavy-metal contamination gradient in the marine environment.microbial community composition and structure were characterized in marine sediments contaminated for >80 years with cadmium, copper, lead, and zinc. four sampling sites that encompass a wide range of sediment metal loads were compared in a norwegian fjord (sorfjord). hcl-extractable metals and organic matter constantly decreased from the most contaminated site (s1) to the control site (s4). all sampling sites presented low polychlorinated biphenyl (pcb) concentrations (sigma(7)pcb < 7.0 ng g [d ...200515691917
variations in archaeal and bacterial diversity associated with the sulfate-methane transition zone in continental margin sediments (santa barbara basin, california).the sulfate-methane transition zone (smtz) is a widespread feature of continental margins, representing a diffusion-controlled interface where there is enhanced microbial activity. smtz microbial activity is commonly associated with the anaerobic oxidation of methane (aom), which is carried out by syntrophic associations between sulfate-reducing bacteria and methane-oxidizing archaea. while our understanding of the microorganisms catalyzing aom has advanced, the diversity and ecological role of ...200919139232
development of oligonucleotide probes and pcr primers for detecting phylogenetic subgroups of sulfate-reducing bacteria.pcr primer sets for the 16s rrna gene of six phylogenetic groups of sulfate-reducing bacteria (srb) were designed. their application in conjunction with group-specific internal oligonucleotide probes was used to detect srb dna in samples of landfill leachate. six generic/suprageneric groups could be differentiated: desulfotomaculum:; desulfobulbus:; desulfobacterium:; desulfobacter:; desulfococcus:-desulfonema:-desulfosarcina:; desulfovibrio:-desulfomicrobium: the predicted specificities of the ...200010878133
physiology, phylogenetic relationships, and ecology of filamentous sulfate-reducing bacteria (genus desulfonema)microscopy of organic-rich, sulfidic sediment samples of marine and freshwater origin revealed filamentous, multicellular microorganisms with gliding motility. many of these neither contained sulfur droplets such as the beggiatoa species nor exhibited the autofluorescence of the chlorophyll-containing cyanobacteria. a frequently observed morphological type of filamentous microorganism was enriched under anoxic conditions in the dark with isobutyrate plus sulfate. two strains of filamentous, glid ...199910525735
characterization of microbial communities in anaerobic bioreactors using molecular probes.the microbial community structure of twenty-one single-phase and one two-phase full-scale anaerobic sewage sludge digesters was evaluated using oligonucleotide probes complementary to conserved tracts of the 16s rrnas of phylogenetically defined groups of methanogens and sulfate-reducing bacteria. these probe results were interpreted in combination with results from traditional chemical analyses and metabolic activity assays. it was determined that methanogens in "healthy" mesophilic, single-pha ...19958821785
anaerobic degradation of aniline and dihydroxybenzenes by newly isolated sulfate-reducing bacteria and description of desulfobacterium anilini.a new, rod-shaped, gram-negative, non-sporing sulfate reducer (strain ani1) was enriched and isolated from marine sediment with aniline as sole electron donor and carbon source. the strain degraded aniline completely to co2 and nh3 with stoichiometric reduction of sulfate to sulfide. strain ani1 also degraded aminobenzoates and further aromatic and aliphatic compounds. the strain grew in sulfide-reduced mineral medium supplemented only with vitamin b12 and thiamine. cells contained cytochromes, ...19892589921
nested pcr-denaturing gradient gel electrophoresis approach to determine the diversity of sulfate-reducing bacteria in complex microbial communities.here, we describe a three-step nested-pcr-denaturing gradient gel electrophoresis (dgge) strategy to detect sulfate-reducing bacteria (srb) in complex microbial communities from industrial bioreactors. in the first step, the nearly complete 16s rrna gene was amplified using bacterial primers. subsequently, this product was used as a template in a second pcr with group-specific srb primers. a third round of amplification was conducted to obtain fragments suitable for dgge. the largest number of b ...200515870318
characterization of the marine propionate-degrading, sulfate-reducing bacterium desulfofaba fastidiosa sp. nov. and reclassification of desulfomusa hansenii as desulfofaba hansenii comb. nov.a rod-shaped, slightly curved sulfate reducer, designated strain p2(t), was isolated from the sulfate-methane transition zone of a marine sediment. cells were motile by means of a single polar flagellum. the strain reduced sulfate, thiosulfate and sulfite to sulfide and used propionate, lactate and 1-propanol as electron donors. strain p2(t) also grew by fermentation of lactate. propionate was oxidized incompletely to acetate and co(2). the dna g+c content was 48.8 mol%. sequence analysis of the ...200415023950
desulfomusa hansenii gen. nov., sp. nov., a novel marine propionate-degrading, sulfate-reducing bacterium isolated from zostera marina roots.the physiology and phylogeny of a novel sulfate-reducing bacterium, isolated from surface-sterilized roots of the marine macrophyte zostera marina, are presented. the strain, designated p1t, was enriched and isolated in defined oxygen-free, bicarbonate-buffered, iron-reduced seawater medium with propionate as sole carbon source and electron donor and sulfate as electron acceptor. strain p1t had a rod-shaped, slightly curved cell morphology and was motile by means of a single polar flagellum. cel ...200111760947
community structure, cellular rrna content, and activity of sulfate-reducing bacteria in marine arctic sediments.the community structure of sulfate-reducing bacteria (srb) of a marine arctic sediment (smeerenburgfjorden, svalbard) was characterized by both fluorescence in situ hybridization (fish) and rrna slot blot hybridization by using group- and genus-specific 16s rrna-targeted oligonucleotide probes. the srb community was dominated by members of the desulfosarcina-desulfococcus group. this group accounted for up to 73% of the srb detected and up to 70% of the srb rrna detected. the predominance was sh ...200010919825
selenocysteine-containing proteins in anaerobic benzoate metabolism of desulfococcus multivorans.the sulfate-reducing bacterium desulfococcus multivorans uses various aromatic compounds as sources of cell carbon and energy. in this work, we studied the initial steps in the aromatic metabolism of this strictly anaerobic model organism. an atp-dependent benzoate coenzyme a (coa) ligase (amp plus ppi forming) composed of a single 59-kda subunit was purified from extracts of cells grown on benzoate. specific activity was highest with benzoate and some benzoate derivatives, whereas aliphatic car ...200415028701
treatment of dye works wastewater using anaerobic-oxic biological filter reactor packed with carbon fibre and aerated with micro-bubbles.a new anaerobic-oxic biological filter reactor, which was packed with carbon fibre and aerated with micro-bubbles, was proposed. the reactor performance was examined using dye works wastewater compared with the activated sludge reactor. effluent ss from the experimental reactor was significantly lower than that from the activated sludge reactor, and transparency was higher. temperatures of the activated sludge reactor were over 35 degrees c and doc removal ratios were 40-80% depending on the inf ...200616862785
a study of the relative dominance of selected anaerobic sulfate-reducing bacteria in a continuous bioreactor by fluorescence in situ hybridization.the diversity and the community structure of sulfate-reducing bacteria (srb) in an anaerobic continuous bioreactor used for treatment of a sulfate-containing wastewater were investigated by fluorescence in situ hybridization. hybridization to the 16s rrna probe eub338 for the domain bacteria was performed, followed by a nonsense probe non338 as a control for nonspecific staining. sulfate-reducing consortia were identified by using five nominally genus-specific probes (srb129 for desulfobacter, s ...200716941240
in vitro cell growth of marine archaeal-bacterial consortia during anaerobic oxidation of methane with sulfate.anoxic sediment from a methane hydrate area (hydrate ridge, north-east pacific; water depth 780 m) was incubated in a long-term laboratory experiment with semi-continuous supply of pressurized [1.4 mpa (14 atm)] methane and sulfate to attempt in vitro propagation of the indigenous consortia of archaea (anme-2) and bacteria (dss, desulfosarcina/desulfococcus cluster) to which anaerobic oxidation of methane (aom) with sulfate has been attributed. during 24 months of incubation, the rate of aom (me ...200717227423
adaptation of anaerobically grown thauera aromatica, geobacter sulfurreducens and desulfococcus multivorans to organic solvents on the level of membrane fatty acid composition.the effect of different solvents and pollutants on the cellular fatty acid composition of three bacterial strains: thauera aromatica, geobacter sulfurreducens and desulfococcus multivorans, representatives of diverse predominant anaerobic metabolisms was investigated. as the prevailing adaptive mechanism in cells of t. aromatica and g. sulfurreducens whose cellular fatty acids patterns were dominated by palmitic acid (c16:0) and palmitoleic acid (c16:1cis), the cells reacted by an increase in th ...201021255320
diversity of sulfate-reducing genes (dsrab) in sediments from puget sound.the aims of this study were to characterize the population structure and diversity of sulfate-reducing bacteria (srb) from three distinct sites at puget sound, and relate the biogeochemical properties of the sediments to the sulfate-reducer communities. the population composition and diversity of sulfate-reducing bacteria carrying dsrab genes from surface puget sound sediments was investigated using a polymerase chain reaction-based cloning approach. sediment cores were collected from three diff ...200818942577
structural basis for promoting and preventing decarboxylation in glutaryl-coenzyme a dehydrogenases.glutaryl-coenzyme a dehydrogenases (gdhs) involved in amino acid degradation were thought to catalyze both the dehydrogenation and decarboxylation of glutaryl-coenzyme a to crotonyl-coenzyme a and co(2). recently, a structurally related but nondecarboxylating, glutaconyl-coenzyme a-forming gdh was characterized in the obligately anaerobic bacteria desulfococcus multivorans (gdh(des)) which conserves the free energy of decarboxylation by a na(+)-pumping glutaconyl-coenzyme a decarboxylase. to und ...201020486657
sulfate-reducing bacteria in marine sediment (aarhus bay, denmark): abundance and diversity related to geochemical zonation.in order to better understand the main factors that influence the distribution of sulfate-reducing bacteria (srb), their population size and their metabolic activity in high- and low-sulfate zones, we studied the srb diversity in 3- to 5-m-deep sediment cores, which comprised the entire sulfate reduction zone and the upper methanogenic zone. by combining ema (ethidium monoazide that can only enter damaged/dead cells and may also bind to free dna) treatment with real-time pcr, we determined the d ...200919220398
diversity and distribution of methanotrophic archaea at cold seeps.in this study we investigated by using 16s rrna-based methods the distribution and biomass of archaea in samples from (i) sediments above outcropping methane hydrate at hydrate ridge (cascadia margin off oregon) and (ii) massive microbial mats enclosing carbonate reefs (crimea area, black sea). the archaeal diversity was low in both locations; there were only four (hydrate ridge) and five (black sea) different phylogenetic clusters of sequences, most of which belonged to the methanotrophic archa ...200515640223
alkane biodegradation and dynamics of phylogenetic subgroups of sulfate-reducing bacteria in an anoxic coastal marine sediment artificially contaminated with oil.for 503 days, unoiled control and artificially oiled sediments were incubated in situ at 20m water depth in a mediterranean coastal area. degradation of the aliphatic fraction of the oil added was followed by gc-ms. at the same time, terminal restriction fragment length polymorphism (t-rflp) of 16s rrna encoding genes was used to detect dynamics in the sulfate-reducing bacteria (srb) community in response to the oil contamination. specific polymerase chain reaction (pcr) primer sets for five gen ...200717337033
evidence for anaerobic oxidation of methane in sediments of a freshwater system (lago di cadagno).anaerobic oxidation of methane (aom) has been investigated in sediments of a high alpine sulfate-rich lake. hot spots of aom could be identified based on geochemical and isotopic evidence. very high fractionation of methane (α=1.031) during oxidation was observed in the uppermost sediment layers, where methane is oxidized most likely with sulfate-containing bottom waters. however, we could not exclude that other electron acceptors such as iron, or manganese might also be involved. light carbon i ...201121244447
identification of the dominant sulfate-reducing bacterial partner of anaerobic methanotrophs of the anme-2 clade.summary the anaerobic oxidation of methane (aom) with sulfate as terminal electron acceptor is mediated by consortia of methanotrophic archaea (anme) and sulfate-reducing bacteria (srb). whereas three clades of anme have been repeatedly studied with respect to phylogeny, key genes and genomic capabilities, little is known about their sulfate-reducing partner. in order to identify the partner of anaerobic methanotrophs of the anme-2 clade, bacterial 16s rrna gene libraries were constructed from c ...201020629706
microbial reefs in the black sea fueled by anaerobic oxidation of methane.massive microbial mats covering up to 4-meter-high carbonate buildups prosper at methane seeps in anoxic waters of the northwestern black sea shelf. strong 13c depletions indicate an incorporation of methane carbon into carbonates, bulk biomass, and specific lipids. the mats mainly consist of densely aggregated archaea (phylogenetic anme-1 cluster) and sulfate-reducing bacteria (desulfosarcina/desulfococcus group). if incubated in vitro, these mats perform anaerobic oxidation of methane coupled ...200212169733
[distribution and diversity of sulfate-reducing bacteria in a crude oil gathering and transferring system].the distribution of sulfureted hydrogen (h2s) as well as sulfate-reducing bacteria (srb) distribution and diversity in crude oil and oilfield production water samples from a oil gathering and transferring system in changqing oilfield of china were investigated by methylene blue colorimetric method, the most probable number technique and sequence analysis of the 16s rrna gene, respectively. at the oil gathering and transferring system which from oil well through oil flowstation and then to oil co ...201021072940
decarboxylating and nondecarboxylating glutaryl-coenzyme a dehydrogenases in the aromatic metabolism of obligately anaerobic bacteria.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 e ...200919395484
a comparison of stable-isotope probing of dna and phospholipid fatty acids to study prokaryotic functional diversity in sulfate-reducing marine sediment enrichment slurries.marine sediment slurries enriched for anaerobic, sulfate-reducing prokaryotic communities utilizing glucose and acetate were used to provide the first comparison between stable-isotope probing (sip) of phospholipid fatty acids (plfa) and dna (16s rrna and dsra genes) biomarkers. different 13c-labelled substrates (glucose, acetate and pyruvate) at low concentrations (100 microm) were used over a 7-day incubation to follow and identify carbon flow into different members of the community. limited c ...200616913918
stable isotope fractionation of gamma-hexachlorocyclohexane (lindane) during reductive dechlorination by two strains of sulfate-reducing bacteria.carbon isotope fractionation factors were determined with the dichloro elimination of gamma-hexachlorocyclohexane (gamma-hch) by the sulfate-reducing bacteria desulfococcus multivorans dsm 2059 and desulfovibrio gigas dsm 1382. both strains are known for cometabolic hch dechlorination. degradation experiments with gamma-hch in concentrations of 22-25 gammam were carried out using benzoate (for d. multivorans) and lactate (for d. gigas) as electron donors, respectively. gamma-hch was dechlorinate ...200919534128
analyses of the vrl gene cluster in desulfococcus multivorans: homologous to the virulence-associated locus of the ovine footrot pathogen dichelobacter nodosus strain a198.major parts of the virulence-associated vrl locus known from the gammaproteobacterium dichelobacter nodosus, the causative agent of ovine footrot, were analyzed in the genome of the sulfate-reducing deltaproteobacterium desulfococcus multivorans. in the genome of d. multivorans 13 of the 19 vrl genes described for d. nodosus are present and highly conserved with respect to gene sequence and order. the vrl locus and its flanking regions suggest a bacteriophage-mediated transfer into the genome of ...200717693723
characterization of the microbial community from the marine sediment of the venice lagoon capable of reductive dechlorination of coplanar polychlorinated biphenyls (pcbs).the native microbial community of a contaminated sediment from brentella canal (venice lagoon, italy) was enriched in slurry microcosms consisting of sterile sediment suspended in sterile site water in the presence of 3,3',4,4'-tetrachlorobiphenyl, 3,3',4,4',5- and 2,3',4,4',5-pentachlorobiphenyls, 3,3',4,4',5,5'- and 2,3,3',4,4',5-hexachlorobiphenyls. the enrichment cultures were characterized at each subculturing step by 16s rrna gene terminal-restriction fragment length polymorphism (t-rflp) ...201020153926
anaerobically grown thauera aromatica, desulfococcus multivorans, geobacter sulfurreducens are more sensitive towards organic solvents than aerobic bacteria.the effect of seven important pollutants and three representative organic solvents on growth of thauera aromatica k172, as reference strain for nitrate-reducing anaerobic bacteria, was investigated. toxicity in form of the effective concentrations (ec50) that led to 50% growth inhibition of potential organic pollutants such as btex (benzene, toluene, ethylbenzene, and xylene), chlorinated phenols and aliphatic alcohols on cells was tested under various anaerobic conditions. similar results were ...200717876576
diversity of dissimilatory sulfite reductase genes (dsrab) in a salt marsh impacted by long-term acid mine drainage.sulfate-reducing bacteria (srb) play a major role in the coupled biogeochemical cycling of sulfur and chalcophilic metal(loid)s. by implication, they can exert a strong influence on the speciation and mobility of multiple metal(loid) contaminants. in this study, we combined dsrab gene sequencing and sulfur isotopic profiling to identify the phylogeny and distribution of srb and to assess their metabolic activity in salt marsh sediments exposed to acid mine drainage (amd) for over 100 years. reco ...201020472728
anaerobic oxidation of short-chain hydrocarbons by marine sulphate-reducing bacteria.the short-chain hydrocarbons ethane, propane and butane are constituents of natural gas. they are usually assumed to be of thermochemical origin, but biological formation of ethane and propane has been also observed. microbial utilization of short-chain hydrocarbons has been shown in some aerobic species but not in anaerobic species of bacteria. on the other hand, anaerobic utilization of short-chain hydrocarbons would in principle be expected because various anaerobic bacteria grow with higher ...200717882164
diversity and biogeochemical structuring of bacterial communities across the porangahau ridge accretionary prism, new zealand.sediments from the porangahau ridge, located off the northeastern coast of new zealand, were studied to describe bacterial community structure in conjunction with differing biogeochemical regimes across the ridge. low diversity was observed in sediments from an eroded basin seaward of the ridge and the community was dominated by uncultured members of the burkholderiales. chloroflexi/gns and deltaproteobacteria were abundant in sediments from a methane seep located landward of the ridge. gas-char ...201121595727
sensitive detection of selenoproteins in gel electrophoresis by high repetition rate femtosecond laser ablation-inductively coupled plasma mass spectrometry.a laser ablation-icpms method using an infrared (1030 nm), low-energy (39 microj/pulse), high repetition rate (10 khz), femtosecond laser was developed to improve the sensitivity of detection of heteroatom-containing proteins in 1d polyacrylamide gels. a 2-mm-wide lane was ablated by ultrafast (10 cm s(-1)) back-and-forth movement of a 20-microm laser beam parallel to the protein bands while the gel advanced perpendicularly. this procedure resulted in a considerable increase in detection sensiti ...200717665877
bacterial enzymes for dissimilatory sulfate reduction in a marine microbial mat (black sea) mediating anaerobic oxidation of methane.anaerobic oxidation of methane (aom) with sulfate is catalysed by microbial consortia of archaea and bacteria affiliating with methanogens and sulfate-reducing deltaproteobacteria respectively. there is evidence that methane oxidation is catalysed by enzymes related to those in methanogenesis, but the enzymes for sulfate reduction coupled to aom have not been examined. we collected microbial mats with high aom activity from a methane seep in the black sea. the mats consisted mainly of archaea of ...201121392199
molecular analysis of the spatio-temporal distribution of sulfate-reducing bacteria (srb) in camargue (france) hypersaline microbial mat.the spatio-temporal distribution of sulfate-reducing bacteria (srb) in the microbial mat of camargue (salins-de-giraud, france) was investigated by molecular approaches at both microscale spatial resolution and different taxonomic organization levels. the vertical distribution of the srb populations was correlated with oxygen and sulfide microgradient fluctuations. comparisons of terminal restriction fragment length polymorphism (t-rflp) fingerprints showed distinct locations of some operational ...200817952491
identification of the dominant sulfate-reducing bacterial partner of anaerobic methanotrophs of the anme-2 clade.the anaerobic oxidation of methane (aom) with sulfate as terminal electron acceptor is mediated by consortia of methanotrophic archaea (anme) and sulfate-reducing bacteria (srb). whereas three clades of anme have been repeatedly studied with respect to phylogeny, key genes and genomic capabilities, little is known about their sulfate-reducing partner. in order to identify the partner of anaerobic methanotrophs of the anme-2 clade, bacterial 16s rrna gene libraries were constructed from cultures ...201021966923
cyclohexa-1,5-diene-1-carbonyl-coenzyme a (coa) hydratases of geobacter metallireducens and syntrophus aciditrophicus: evidence for a common benzoyl-coa degradation pathway in facultative and strict anaerobes.in the denitrifying bacterium thauera aromatica, the central intermediate of anaerobic aromatic metabolism, benzoyl-coenzyme a (coa), is dearomatized by the atp-dependent benzoyl-coa reductase to cyclohexa-1,5-diene-1-carbonyl-coa (dienoyl-coa). the dienoyl-coa is further metabolized by a series of beta-oxidation-like reactions of the so-called benzoyl-coa degradation pathway resulting in ring cleavage. recently, evidence was obtained that obligately anaerobic bacteria that use aromatic growth s ...200717122342
structure of microbial communities and hydrocarbon-dependent sulfate reduction in the anoxic layer of a polluted microbial mat.the bacterial communities in the anoxic layer of a heavily polluted microbial mat and their growth on hydrocarbons under sulfate-reducing conditions were investigated. microbial communities were dominated by members of alphaproteobacteria (27% of the total rrna), planctomycetes (21.1%) and sulfate-reducing bacteria (srb: 17.5%). 16s rrna cloning revealed sequences beloning to the same bacterial groups with srb affiliated to the genera desulfobulbus, desulfocapsa, desulfomicrobium, desulfobacteri ...201021194714
anaerobic oxidation of methane at a marine methane seep in a forearc sediment basin off sumatra, indian ocean.a cold methane seep was discovered in a forearc sediment basin off the island sumatra, exhibiting a methane-seep adapted microbial community. a defined seep center of activity, like in mud volcanoes, was not discovered. the seep area was rather characterized by a patchy distribution of active spots. the relevance of anaerobic oxidation of methane (aom) was reflected by (13)c-depleted isotopic signatures of dissolved inorganic carbon. the anaerobic conversion of methane to co(2) was confirmed in ...201122207865
cobalt limitation of growth and mercury methylation in sulfate-reducing bacteria.sulfate-reducing bacteria (srb) have been identified as the primary organisms responsible for monomethylmercury (mehg) production in aquatic environments, but little is known of the physiologyand biochemistry of mercury(hg) methylation. corrinoid compounds have been implicated in enzymatic hg methylation, although recent experiments with a vitamin b12 inhibitor indicated that incomplete-oxidizing srb likely do not use a corrinoid-enzyme for hg methylation, whereas experiments with complete-oxidi ...200818350881
enrichment of anme-1 from eckernförde bay sediment on thiosulfate, methane and short-chain fatty acids.the microorganisms involved in sulfate-dependent anaerobic oxidation of methane (aom) have not yet been isolated. in an attempt to stimulate the growth of anaerobic methanotrophs and associated sulfate reducing bacteria (srb), eckernförde bay sediment was incubated with different combinations of electron donors and acceptors. the organisms involved in aom coupled to sulfate reduction (anme-1, anme-2, and desulfosarcina/desulfococcus) were monitored using specific primers and probes. with thiosul ...201122079869
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