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1.
Curr Microbiol ; 78(5): 1763-1770, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33751185

RESUMO

Degradation of acetone and higher ketones has been described in detail for aerobic and nitrate-reducing bacteria. Among sulfate-reducing bacteria, degradation of acetone and other ketones is still an uncommon ability and has not been understood completely yet. In the present work, we show that Desulfotomaculum arcticum and Desulfotomaculum geothermicum are able to degrade acetone and butanone. Total proteomics of cell-free extracts of both organisms indicated an involvement of a thiamine diphosphate-dependent enzyme, a B12-dependent mutase, and a specific dehydrogenase during acetone degradation. Similar enzymes were recently described to be involved in acetone degradation by Desulfococcus biacutus. As there are so far only two described sulfate reducers able to degrade acetone, D. arcticum and D. geothermicum represent two further species with this capacity. All these bacteria appear to degrade acetone via the same set of enzymes and therefore via the same pathway.


Assuntos
Acetona , Desulfotomaculum , Deltaproteobacteria , Cetonas , Peptococcaceae
2.
Nat Commun ; 11(1): 5075, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033245

RESUMO

Nickel-iron composites are efficient in catalyzing oxygen evolution. Here, we develop a microorganism corrosion approach to construct nickel-iron hydroxides. The anaerobic sulfate-reducing bacteria, using sulfate as the electron acceptor, play a significant role in the formation of iron sulfide decorated nickel-iron hydroxides, which exhibit excellent electrocatalytic performance for oxygen evolution. Experimental and theoretical investigations suggest that the synergistic effect between oxyhydroxides and sulfide species accounts for the high activity. This microorganism corrosion strategy not only provides efficient candidate electrocatalysts but also bridges traditional corrosion engineering and emerging electrochemical energy technologies.


Assuntos
Desulfotomaculum/metabolismo , Hidróxidos/metabolismo , Níquel/metabolismo , Oxigênio/metabolismo , Corrosão , Teoria da Densidade Funcional , Eletroquímica , Eletrodos , Análise Espectral Raman , Espectroscopia por Absorção de Raios X
3.
Environ Microbiol ; 21(10): 3953-3964, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31314939

RESUMO

Around the world, several dozen deep sedimentary aquifers are being used for storage of natural gas. Ad hoc studies of the microbial ecology of some of them have suggested that sulfate reducing and methanogenic microorganisms play a key role in how these aquifers' communities function. Here, we investigate the influence of gas storage on these two metabolic groups by using high-throughput sequencing and show the importance of sulfate-reducing Desulfotomaculum and a new monophyletic methanogenic group. Aquifer microbial diversity was significantly related to the geological level. The distance to the stored natural gas affects the ratio of sulfate-reducing Firmicutes to deltaproteobacteria. In only one aquifer, the methanogenic archaea dominate the sulfate-reducers. This aquifer was used to store town gas (containing at least 50% H2 ) around 50 years ago. The observed decrease of sulfates in this aquifer could be related to stimulation of subsurface sulfate-reducers. These results suggest that the composition of the microbial communities is impacted by decades old transient gas storage activity. The tremendous stability of these gas-impacted deep subsurface microbial ecosystems suggests that in situ biotic methanation projects in geological reservoirs may be sustainable over time.


Assuntos
Archaea/metabolismo , Deltaproteobacteria/metabolismo , Desulfotomaculum/metabolismo , Firmicutes/metabolismo , Sedimentos Geológicos/microbiologia , Gás Natural , Sedimentos Geológicos/química , Geologia , Água Subterrânea/microbiologia , Microbiota , RNA Ribossômico 16S/genética , Sulfatos/metabolismo
4.
Appl Microbiol Biotechnol ; 103(11): 4633-4648, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30972463

RESUMO

Clostridium autoethanogenum and Clostridium ljungdahlii are physiologically and genetically very similar strict anaerobic acetogens capable of growth on carbon monoxide as sole carbon source. While exact nutritional requirements have not been reported, we observed that for growth, the addition of vitamins to media already containing yeast extract was required, an indication that these are fastidious microorganisms. Elimination of complex components and individual vitamins from the medium revealed that the only organic compounds required for growth were pantothenate, biotin and thiamine. Analysis of the genome sequences revealed that three genes were missing from pantothenate and thiamine biosynthetic pathways, and five genes were absent from the pathway for biotin biosynthesis. Prototrophy in C. autoethanogenum and C. ljungdahlii for pantothenate was obtained by the introduction of plasmids carrying the heterologous gene clusters panBCD from Clostridium acetobutylicum, and for thiamine by the introduction of the thiC-purF operon from Clostridium ragsdalei. Integration of panBCD into the chromosome through allele-coupled exchange also conveyed prototrophy. C. autoethanogenum was converted to biotin prototrophy with gene sets bioBDF and bioHCA from Desulfotomaculum nigrificans strain CO-1-SRB, on plasmid and integrated in the chromosome. The genes could be used as auxotrophic selection markers in recombinant DNA technology. Additionally, transformation with a subset of the genes for pantothenate biosynthesis extended selection options with the pantothenate precursors pantolactone and/or beta-alanine. Similarly, growth was obtained with the biotin precursor pimelate combined with genes bioYDA from C. acetobutylicum. The work raises questions whether alternative steps exist in biotin and thiamine biosynthesis pathways in these acetogens.


Assuntos
Clostridium/crescimento & desenvolvimento , Clostridium/metabolismo , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/genética , Vitaminas/biossíntese , Clostridium/genética , Meios de Cultura/química , Desulfotomaculum/genética , Expressão Gênica , Genes Bacterianos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
5.
Microbiologyopen ; 8(3): e00647, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29877051

RESUMO

Recent studies have shown that interspecies electron transfer between chemoheterotrophic bacteria and methanogenic archaea can be mediated by electric currents flowing through conductive iron oxides, a process termed electric syntrophy. In this study, we conducted enrichment experiments with methanogenic microbial communities from rice paddy soil in the presence of ferrihydrite and/or sulfate to determine whether electric syntrophy could be enabled by biogenic iron sulfides. Although supplementation with either ferrihydrite or sulfate alone suppressed methanogenesis, supplementation with both ferrihydrite and sulfate enhanced methanogenesis. In the presence of sulfate, ferrihydrite was transformed into black precipitates consisting mainly of poorly crystalline iron sulfides. Microbial community analysis revealed that a methanogenic archaeon and iron- and sulfate-reducing bacteria (Methanosarcina, Geobacter, and Desulfotomaculum, respectively) predominated in the enrichment culture supplemented with both ferrihydrite and sulfate. Addition of an inhibitor specific for methanogenic archaea decreased the abundance of Geobacter, but not Desulfotomaculum, indicating that Geobacter acquired energy via syntrophic interaction with methanogenic archaea. Although electron acceptor compounds such as sulfate and iron oxides have been thought to suppress methanogenesis, this study revealed that coexistence of sulfate and iron oxide can promote methanogenesis by biomineralization of (semi)conductive iron sulfides that enable methanogenesis via electric syntrophy.


Assuntos
Desulfotomaculum/metabolismo , Compostos Ferrosos/metabolismo , Geobacter/metabolismo , Metano/metabolismo , Methanosarcina/metabolismo , Consórcios Microbianos , Interações Microbianas , Desulfotomaculum/crescimento & desenvolvimento , Geobacter/crescimento & desenvolvimento , Methanosarcina/crescimento & desenvolvimento , Minerais/metabolismo , Oryza/crescimento & desenvolvimento , Microbiologia da Água
6.
J Environ Sci (China) ; 76: 238-248, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30528014

RESUMO

Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane (AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population. Sulfate-reducing bacteria (SRB) (e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus) and anaerobic methanotrophic archaea (ANME) (e.g., Methanosaeta sp. and Methanolinea sp.) coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH4 and SO42- were consumed by methanotrophs and sulfate reducers with CO2 and H2S as products. The H3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H2S from a landfill site. On average, 93.33% of H2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH4.


Assuntos
Sulfeto de Hidrogênio/isolamento & purificação , Sulfeto de Hidrogênio/metabolismo , Metano/isolamento & purificação , Metano/metabolismo , Anaerobiose , Biodegradação Ambiental , Deltaproteobacteria/metabolismo , Desulfotomaculum/metabolismo , Methanomicrobiales/metabolismo , Methanosarcinales/metabolismo , Oxirredução
7.
Int J Syst Evol Microbiol ; 68(9): 2891-2899, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30028279

RESUMO

The genus Desulfotomaculumis a heterogeneous group of spore-forming sulfate-reducing bacteria. The type species of the genus is Desulfotomaculum nigrificans (Approved Lists 1980) emend. Visser et al. 2014. The results of phylogenetic analysis demonstrated that the genus Desulfotomaculum already has lost the clustering monophyly and was segregated into some distinct groups with low sequence similarity. Major features of the type strains in these groups were compared, and four novel genera, Desulfallas gen. nov., Desulfofundulus gen. nov., Desulfofarcimen gen. nov. and Desulfohalotomaculum gen. nov. were proposed to accommodate species transferred from the genus Desulfotomaculum.


Assuntos
Desulfotomaculum/classificação , Filogenia , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
8.
RNA Biol ; 15(4-5): 471-479, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29879865

RESUMO

In many organisms, the UGA stop codon is recoded to insert selenocysteine (Sec) into proteins. Sec incorporation in bacteria is directed by an mRNA element, known as the Sec-insertion sequence (SECIS), located downstream of the Sec codon. Unlike other aminoacyl-tRNAs, Sec-tRNASec is delivered to the ribosome by a dedicated elongation factor, SelB. We recently identified a series of tRNASec-like tRNA genes distributed across Bacteria that also encode a canonical tRNASec. These tRNAs contain sequence elements generally recognized by cysteinyl-tRNA synthetase (CysRS). While some of these tRNAs contain a UCA Sec anticodon, most have a GCA Cys anticodon. tRNASec with GCA anticodons are known to recode UGA codons. Here we investigate the clostridial Desulfotomaculum nigrificans tRNASec-like tRNACys, and show that this tRNA is acylated by CysRS, recognized by SelB, and capable of UGA recoding with Cys in Escherichia coli. We named this non-canonical group of tRNACys as 'tRNAReC' (Recoding with Cys). We performed a comprehensive survey of tRNAReC genes to establish their phylogenetic distribution, and found that, in a particular lineage of clostridial Pelotomaculum, the Cys identity elements of tRNAReC had mutated. This novel tRNA, which contains a UCA anticodon, is capable of Sec incorporation in E. coli, albeit with lower efficiency relative to Pelotomaculum tRNASec. We renamed this unusual tRNASec derived from tRNAReC as 'tRNAReU' (Recoding with Sec). Together, our results suggest that tRNAReC and tRNAReU may serve as safeguards in the production of selenoproteins and - to our knowledge - they provide the first example of programmed codon-anticodon mispairing in bacteria.


Assuntos
Aminoacil-tRNA Sintetases/genética , Proteínas de Bactérias/genética , Cisteína/metabolismo , Escherichia coli/genética , RNA de Transferência de Cisteína/genética , Selenocisteína/metabolismo , Selenoproteínas/genética , Aminoacil-tRNA Sintetases/metabolismo , Anticódon/genética , Anticódon/metabolismo , Proteínas de Bactérias/metabolismo , Códon de Terminação/química , Códon de Terminação/metabolismo , Desulfotomaculum/genética , Desulfotomaculum/metabolismo , Escherichia coli/metabolismo , Código Genético , Modelos Moleculares , Mutação , Conformação de Ácido Nucleico , Fator Tu de Elongação de Peptídeos/genética , Fator Tu de Elongação de Peptídeos/metabolismo , Peptococcaceae/genética , Peptococcaceae/metabolismo , Biossíntese de Proteínas , RNA de Transferência de Cisteína/metabolismo , Ribossomos/genética , Ribossomos/metabolismo , Selenoproteínas/biossíntese
9.
Geobiology ; 16(5): 522-539, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29905980

RESUMO

We established Fe(III)-reducing co-cultures of two species of metal-reducing bacteria, the Gram-positive Desulfotomaculum reducens MI-1 and the Gram-negative Geobacter sulfurreducens PCA. Co-cultures were given pyruvate, a substrate that D. reducens can ferment and use as electron donor for Fe(III) reduction. G. sulfurreducens relied upon products of pyruvate oxidation by D. reducens (acetate, hydrogen) for use as electron donor in the co-culture. Co-cultures reduced Fe(III) to Fe(II) robustly, and Fe(II) was consistently detected earlier in co-cultures than pure cultures. Notably, faster cell growth, and correspondingly faster pyruvate oxidation, was observed by D. reducens in co-cultures. Global comparative proteomic analysis was performed to observe differential protein abundance during co-culture vs. pure culture growth. Proteins previously associated with Fe(III) reduction in G. sulfurreducens, namely c-type cytochromes and type IV pili proteins, were significantly increased in abundance in co-cultures relative to pure cultures. D. reducens ribosomal proteins were significantly increased in co-cultures, likely a reflection of faster growth rates observed for D. reducens cells while in co-culture. Furthermore, we developed multiple reaction monitoring (MRM) assays to quantitate specific biomarker peptides. The assays were validated in pure and co-cultures, and protein abundance ratios from targeted MRM and global proteomic analysis correlate significantly.


Assuntos
Compostos Férricos/metabolismo , Proteômica/métodos , Desulfotomaculum/metabolismo , Geobacter/metabolismo , Oxirredução , Proteoma/metabolismo
10.
Nat Commun ; 9(1): 239, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29339722

RESUMO

Methanol is generally metabolized through a pathway initiated by a cobalamine-containing methanol methyltransferase by anaerobic methylotrophs (such as methanogens and acetogens), or through oxidation to formaldehyde using a methanol dehydrogenase by aerobes. Methanol is an important substrate in deep-subsurface environments, where thermophilic sulfate-reducing bacteria of the genus Desulfotomaculum have key roles. Here, we study the methanol metabolism of Desulfotomaculum kuznetsovii strain 17T, isolated from a 3000-m deep geothermal water reservoir. We use proteomics to analyze cells grown with methanol and sulfate in the presence and absence of cobalt and vitamin B12. The results indicate the presence of two methanol-degrading pathways in D. kuznetsovii, a cobalt-dependent methanol methyltransferase and a cobalt-independent methanol dehydrogenase, which is further confirmed by stable isotope fractionation. This is the first report of a microorganism utilizing two distinct methanol conversion pathways. We hypothesize that this gives D. kuznetsovii a competitive advantage in its natural environment.


Assuntos
Álcool Desidrogenase/metabolismo , Proteínas de Bactérias/metabolismo , Desulfotomaculum/enzimologia , Redes e Vias Metabólicas/genética , Metanol/metabolismo , Metiltransferases/metabolismo , Álcool Desidrogenase/genética , Proteínas de Bactérias/genética , Cobalto/metabolismo , Cobalto/farmacologia , Meios de Cultura/química , Desulfotomaculum/genética , Expressão Gênica , Perfilação da Expressão Gênica , Hidrólise , Metiltransferases/genética , Oxirredução , Filogenia , Proteômica/métodos , Vitamina B 12/metabolismo , Vitamina B 12/farmacologia
11.
Environ Microbiol ; 20(1): 281-292, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29124868

RESUMO

Mesotoga prima strain PhosAc3 is a mesophilic representative of the phylum Thermotogae comprising only fermentative bacteria so far. We show that while unable to ferment glucose, this bacterium is able to couple its oxidation to reduction of elemental sulfur. We demonstrate furthermore that M. prima strain PhosAc3 as well as M. prima strain MesG1 and Mesotoga infera are able to grow in syntrophic association with sulfate-reducing bacteria (SRB) acting as hydrogen scavengers through interspecies hydrogen transfer. Hydrogen production was higher in M. prima strain PhosAc3 cells co-cultured with SRB than in cells cultured alone in the presence of elemental sulfur. We propose that the efficient sugar-oxidizing metabolism by M. prima strain PhosAc3 in syntrophic association with a hydrogenotrophic sulfate-reducing bacterium can be extrapolated to all members of the Mesotoga genus. Genome comparison of Thermotogae members suggests that the metabolic difference between Mesotoga and Thermotoga species (sugar oxidation versus fermentation) is mainly due to the absence of the bifurcating [FeFe]-hydrogenase in the former. Such an obligate oxidative process for using sugars, unusual within prokaryotes, is the first reported within the Thermotogae. It is hypothesized to be of primary ecological importance for growth of Mesotoga spp. in the environments that they inhabit.


Assuntos
Metabolismo dos Carboidratos/fisiologia , Desulfotomaculum/metabolismo , Desulfovibrio vulgaris/metabolismo , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/metabolismo , Açúcares/metabolismo , Simbiose/fisiologia , Técnicas de Cocultura , Fermentação/fisiologia , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/crescimento & desenvolvimento , Hidrogênio/metabolismo , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sulfatos/metabolismo , Enxofre/metabolismo
12.
Int J Syst Evol Microbiol ; 67(8): 2679-2682, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28786781

RESUMO

A mesophilic, endospore-forming, sulfate-reducing bacterium, designated strain NAW-5T, was isolated from marsh soil. Cells of strain NAW-5T were Gram-stain-negative, curved rods that were motile. Strain NAW-5T grew at 18-48 °C (optimum 32-37 °C) and pH 5.8-8.4 (optimum pH 6.2-7.3). Electron donors utilized were various organic acids and H2 which support autotrophic growth. Fermentative growth occurred on carboxylic acids, but not on sugar. Sulfate, thiosulfate and elemental sulfur were used as electron acceptors. The respiratory isoprenoid quinone was MK-7. The genomic DNA G+C content of this strain was 46.6 mol%. Sequence analysis of the 16S rRNA gene showed that strain NAW-5T was affiliated to the family 'Desulfotomaculaceae' but the strain shared very low sequence similarity with any representatives of this family (≥89 %). Strain NAW-5T belongs to Desulfotomaculum subcluster Ig which does not include any species with validly published names. On the basis of significant differences in the phylogenetic and phenotypic properties between strain NAW-5T and related species, strain NAW-5T represents a novel species of a new genus for which the name Desulfocucumis palustris gen. nov., sp. nov. is proposed. The type strain of the type species is NAW-5T (=DSM 102911T=NBRC 112242T).


Assuntos
Desulfotomaculum/classificação , Filogenia , Microbiologia do Solo , Áreas Alagadas , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Japão , Oxirredução , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sulfatos/metabolismo , Enxofre/metabolismo , Tiossulfatos/metabolismo , Vitamina K 2/análogos & derivados , Vitamina K 2/química
13.
J Biomed Mater Res B Appl Biomater ; 105(1): 222-229, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-26465349

RESUMO

Corrosion processes of metallic biomaterials in the oral cavity pose a significant limitation to the life and reliable functioning of dental materials. In this article, the influence of environment bacteria Desulfotomaculum nigrificans sulfate reducing bacteria on the corrosion processes of 316LV steel was assessed. After 14 and 28 days of contact of the material with the bacterial environment, the surfaces of the tested biomaterial were observed by means of confocal scanning laser microscopy, and their chemical composition was studied using X-Ray Photoelectron Spectrometry and a scanning transmission electron microscopy. Corrosive changes, the presence of sulfur (with atomic concentration of 0.5%) on the surface of the biomaterial and the presence of a thin oxide layer (thickness of ∼20 nm) under the surface of the steel were observed. This corrosion layer with significant size reduction of grains was characterized by an increased amount of oxygen (18% mas., p < 0.001) in comparison to untreated 316LV steel (where oxygen concentration - 10% mas.). Image analysis conducted using APHELION software indicated that corrosion pits took up ∼2.8% of the total tested surface. The greatest number of corrosion pits had a surface area within the range of 100-200 µm2 . © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 222-229, 2017.


Assuntos
Biofilmes/crescimento & desenvolvimento , Desulfotomaculum/fisiologia , Boca/microbiologia , Aço/química , Corrosão , Humanos
14.
Int J Syst Evol Microbiol ; 66(11): 4329-4338, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27473224

RESUMO

Two novel strictly anaerobic bacteria, strains Bs105T and Bs107T, were isolated from a deep aquifer-derived hydrocarbonoclastic community. The cells were rod-shaped, not motile and had terminal spores. Phylogenetic affiliation and physiological properties revealed that these isolates belong to two novel species of the genus Desulfotomaculum. Optimal growth temperatures for strains Bs105T and Bs107T were 42 and 45 °C, respectively. The estimated G+C content of the genomic DNA was 42.9 and 48.7 mol%. For both strains, the major cellular fatty acid was palmitate (C16 : 0). Specific carbon fatty acid signatures of Gram-positive bacteria (iso-C17 : 0) and sulfate-reducing bacteria (C17 : 0cyc) were also detected. An insertion was revealed in one of the two 16S rRNA gene copies harboured by strain Bs107T. Similar insertions have previously been highlighted among moderately thermophilic species of the genus Desulfotomaculum. Both strains shared the ability to oxidize aromatic acids (Bs105T: hydroquinone, acetophenone, para-toluic acid, 2-phenylethanol, trans-cinnamic acid, 4-hydroxybenzaldehyde, benzyl alcohol, benzoic acid 4-hydroxybutyl ester; Bs107T: ortho-toluic acid, benzoic acid 4-hydroxybutyl ester). The names Desulfotomaculum aquiferis sp. nov. and Desulfotomaculum profundi sp. nov. are proposed for the type strains Bs105T (=DSM 24088T=JCM 31386T) and Bs107T (=DSM 24093T=JCM 31387T).


Assuntos
Desulfotomaculum/classificação , Água Subterrânea/microbiologia , Gás Natural , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Desulfotomaculum/genética , Desulfotomaculum/isolamento & purificação , Ácidos Graxos/química , França , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
15.
Int J Syst Evol Microbiol ; 66(8): 3022-3028, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27153808

RESUMO

A novel dissimilatory Fe(III)-reducing bacterium, designated strain GSS09T, was isolated from a compost sample by using a solid medium containing acetate and ferrihydrite as electron donor and electron acceptor, respectively. Cells of strain GSS09T were anaerobic, Gram-stain-positive, motile, endospore-forming and rod-shaped. Growth occurred at 30-55 °C (optimum 50 °C), at pH 6.5-9.0 (optimum pH 7.5) and in the presence of 0-3 % (w/v) NaCl (optimum 1 %). Both sulfur compounds such as sulfate, sulfite and thiosulfate and Fe(III) oxides such as ferrihydrite could be utilized as electron acceptors. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GSS09T was related closely to Desulfotomaculum hydrothermale Lam5T (94.5 % sequence similarity). The major fatty acids were C16 : 0 and C16 : 1ω7c/C16 : 1ω6c. The G+C content of the genomic DNA was 49.1 mol%. On the basis of phylogenetic analysis, phenotypic characterization and physiological tests, strain GSS09T is considered to represent a novel species of the genus Desulfotomaculum, for which the name Desulfotomaculum ferrireducens sp. nov. is proposed. The type strain is GSS09T (=KCTC 15523T=MCCC 1K01254T).


Assuntos
Desulfotomaculum/classificação , Compostos Férricos/metabolismo , Filogenia , Microbiologia do Solo , Sulfatos/metabolismo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Desulfotomaculum/genética , Desulfotomaculum/isolamento & purificação , Ácidos Graxos/química , Oxirredução , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sulfitos/metabolismo
16.
PLoS One ; 11(1): e0146689, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26800443

RESUMO

Although iron- and sulfate-reducing bacteria in subsurface environments have crucial roles in biogeochemical cycling of C, Fe, and S, how specific electron donors impact the compositional structure and activity of native iron- and/or sulfate-reducing communities is largely unknown. To understand this better, we created bicarbonate-buffered batch systems in duplicate with three different electron donors (acetate, lactate, or glucose) paired with ferrihydrite and sulfate as the electron acceptors and inoculated them with subsurface sediment as the microbial inoculum. Sulfate and ferrihydrite reduction occurred simultaneously and were faster with lactate than with acetate. 16S rRNA-based sequence analysis of the communities over time revealed that Desulfotomaculum was the major driver for sulfate reduction coupled with propionate oxidation in lactate-amended incubations. The reduction of sulfate resulted in sulfide production and subsequent abiotic reduction of ferrihydrite. In contrast, glucose promoted faster reduction of ferrihydrite, but without reduction of sulfate. Interestingly, the glucose-amended incubations led to two different biogeochemical trajectories among replicate bottles that resulted in distinct coloration (white and brown). The two outcomes in geochemical evolution might be due to the stochastic evolution of the microbial communities or subtle differences in the initial composition of the fermenting microbial community and its development via the use of different glucose fermentation pathways available within the community. Synchrotron-based x-ray analysis indicated that siderite and amorphous Fe(II) were formed in the replicate bottles with glucose, while ferrous sulfide and vivianite were formed with lactate or acetate. These data sets reveal that use of different C utilization pathways projects significant changes in microbial community composition over time that uniquely impact both the geochemistry and mineralogy of subsurface environments.


Assuntos
Ácido Acético/metabolismo , Desulfotomaculum/metabolismo , Compostos Férricos/metabolismo , Glucose/metabolismo , Ácido Láctico/metabolismo , Consórcios Microbianos/fisiologia , Sulfatos/metabolismo , Sequência de Bases , Biodegradação Ambiental , Carbono/química , Carbonatos/metabolismo , DNA Bacteriano/genética , DNA Ribossômico/genética , Desulfotomaculum/genética , Elétrons , Metabolismo Energético/fisiologia , Compostos Ferrosos/metabolismo , Redes e Vias Metabólicas/fisiologia , Oxirredução , Fosfatos/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
17.
Acta Bioeng Biomech ; 18(4): 87-96, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28133370

RESUMO

PURPOSE: Degradation processes of metallic biomaterials in the oral cavity limit the stability and reliability of dental materials. The influence of environment bacteria Desulfotomaculum nigrificans sulfate reducing bacteria on the corrosion processes of Co-Cr-Mo and Ti-6Al-4V alloys was assessed. METHODS: After 28 and 56 days of contact of the materials with the bacterial environment, the surfaces of the biomaterials tested were observed by means of confocal scanning laser microscopy (CSLM), and their chemical composition was studied using X-Ray Photoelectron Spectrometry (XPS). RESULTS: Corrosive changes and the presence of sulfur (with medium atomic concentration of 0.5% for Co-Cr-Mo and 0.3% for Ti-6AL-4V) were observed on the surface of the biomaterials. Image analysis conducted using Aphelion software indicated that corrosion pits took up approx. 2.3% and 1.8% (after 28 days) and 4.2% and 3.1% (after 56 days) of the total test surfaces of cobalt and titanium alloys respectively. The greatest number of corrosion pits had a surface area within the range of 1-50 m2. They constituted from 37% up to 83% of all changes, depending on the type of material. CONCLUSIONS: An evident influence of the SRB on the surfaces of cobalt and titanium alloys was observed. Significant corrosive losses caused by the activity of microorganisms were observed on the metallic surfaces under study. The results of this study have much cognitive and utilitarian significance.


Assuntos
Biofilmes/crescimento & desenvolvimento , Corrosão , Ligas Dentárias/química , Desulfotomaculum/metabolismo , Saliva/microbiologia , Enxofre/química , Humanos , Teste de Materiais
18.
Mikrobiol Z ; 77(5): 20-8, 2015.
Artigo em Ucraniano | MEDLINE | ID: mdl-26638481

RESUMO

Sulphate-reducing bacteria Desulfomicrobium sp. CrR3 and Desulfotomaculum. sp. are able to use fumarate as electron donor and acceptor. When they use fumarate as an electron acceptor succinate accumulates in the medium. If fumarate serves as electron donor, minor amounts of citrate, isocitrate and acetate are detected except succinate. In the case of simultaneous introduction of fumarate, SO4(2-) and Cr2O7(2-), the last inhibits usage of fumarate and SO4(2-).


Assuntos
Desulfotomaculum/metabolismo , Fumaratos/metabolismo , Técnicas Bacteriológicas , Biomassa , Desulfotomaculum/crescimento & desenvolvimento , Transporte de Elétrons , Dicromato de Potássio/metabolismo , Sulfatos/metabolismo , Bactérias Redutoras de Enxofre/crescimento & desenvolvimento , Bactérias Redutoras de Enxofre/metabolismo
19.
Biochem Biophys Res Commun ; 467(3): 503-8, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26454174

RESUMO

Desulfotomaculum reducens MI-1 is a Firmicute strain capable of reducing a variety of heavy metal ions and has a great potential in heavy metal bioremediation. We recently identified Dred_2421 as a potential iron reductase through proteomic study of D. reducens. The current study examines its iron-reduction mechanism. Dred_2421, like its close homolog from Escherichia coli (2, 4-dienoyl-CoA reductase), has an FMN-binding N-terminal domain (NTD), an FAD-binding C-terminal domain (CTD), and a 4Fe-4S cluster between the two domains. To understand the mechanism of the iron-reduction activity and the role of each domain, we generated a series of variants for each domain and investigated their iron-reduction activity. Our results suggest that CTD is the main contributor of the iron-reduction activity, and that NTD and the 4Fe-4S cluster are not directly involved in such activity. This study provides a mechanistic understanding of the iron-reductase activity of Dred_2421 and may also help to elucidate other physiological activities this enzyme may have.


Assuntos
Desulfotomaculum/enzimologia , FMN Redutase/metabolismo , FMN Redutase/genética
20.
Mikrobiologiia ; 84(2): 250-60, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26263632

RESUMO

Biodiversity of sulfate-reducing bacterial communities in the water column of the Gdansk Deep, Baltic Sea, where H2S had been detected in near-bottom layers, was analyzed by PCR with primers for the 16S rRNA genes of six major phylogenetic subgroups of sulfate-reducing bacteria (SRB). Using denaturing gradient gel electrophoresis followed by sequencing, the nucleotide sequences of reamplified dsrB gene fragments from investigated water samples were determined. For the first time the presence of nucleotide sequences of the dsrB gene was detected by PCR in the water samples from all hydrochemical layers, including subsurface oxic waters. The presence of the 16S rRNA genes of representatives of Desulfotomaculum, Desulfococcus-Desulfonema-Desulfosarcina, and Desulfovibrio-Desulfomicrobium SRB subgroups was also revealed throughout the water column of the Gdansk Deep. Analysis of translated amino acid sequences encoded by the dsrB gene demonstrated the highest homology with the relevant sequences of uncultured SRB from various marine habitats.


Assuntos
Deltaproteobacteria/classificação , Desulfotomaculum/classificação , Desulfovibrio/classificação , Genes Bacterianos , Bactérias Redutoras de Enxofre/classificação , Microbiologia da Água , Oceano Atlântico , Contagem de Colônia Microbiana , Deltaproteobacteria/genética , Deltaproteobacteria/metabolismo , Desulfotomaculum/genética , Desulfotomaculum/metabolismo , Desulfovibrio/genética , Desulfovibrio/metabolismo , Genes de RNAr , Sulfeto de Hidrogênio/metabolismo , Consórcios Microbianos/genética , Oxirredução , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Bactérias Redutoras de Enxofre/genética , Bactérias Redutoras de Enxofre/metabolismo
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