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Gerhard Gottschalk - One of the best experts on this subject based on the ideXlab platform.
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H2: heterodisulfide oxidoreductase, a second energy-conserving system in the Methanogenic strain Gö1
Archives of Microbiology, 1991Co-Authors: Uwe Deppenmeier, Michael Blaut, Gerhard GottschalkAbstract:Washed everted vesicles of the Methanogenic Bacterium strain Go1 catalyzed an H2-dependent reduction of the heterodisulfide of HS-CoM (2-mercaptoethanesulfonate) and HS-HTP (7-mercaptoheptanoylthreonine phosphate) (CoM-S-S-HTP). This process was independent of coenzyme F420 and was coupled to proton translocation across the cytoplasmic membrane into the lumen of the everted vesicles. The maximal H+/CoM-S-S-HTP ratio was 2. The tranmembrane electrochemical gradient thereby generated was shown to induce ATP synthesis from ADP+Pi, exhibiting a stoichiometry of 1 ATP synthesized per 2 CoM-S-S-HTP reduced (H+/ATP=4). ATP formation was inhibited by the uncoupler 3,5-di-tert-butyl-4-hydroxy-benzylidene-malononitrile (SF 6847) and by the ATP synthase inhibitor N,N′-dicyclohexylcarbodiimide (DCCD). This energy-conserving system showed a stringent coupling. The addition of HS-CoM and HS-HTP at 1 mM each decreased the heterodisulfide reductase activity to 50% of the control. Membranes from Methanolobus tindarius showed F420H2-dependent but no H2-dependent heterodisulfide oxidoreductase activity. Neither of these activities was detectable in membranes of Methanococcus thermolithotrophicus.
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Reduced coenzyme F420: heterodisulfide oxidoreductase, a proton- translocating redox system in Methanogenic bacteria.
Proceedings of the National Academy of Sciences of the United States of America, 1990Co-Authors: Uwe Deppenmeier, Michael Blaut, Andreas Mahlmann, Gerhard GottschalkAbstract:Abstract Washed everted vesicles of the Methanogenic Bacterium strain Go1 were found to couple the F420H2-dependent heterodisulfide reduction with the transfer of protons across the membrane into the lumen of the everted vesicles. The transmembrane electrochemical potential of protons thereby generated was shown to be competent in driving ATP synthesis from ADP + Pi, exhibiting a stoichiometry of 2 H+ translocated or 0.4 ATP synthesized per F420H2 oxidized. This enzyme system exhibits the phenomenon of coupling and uncoupling and represents a different kind of electron transport chain with the heterodisulfide of 2-mercaptoethanesulfonate and 7-mercaptoheptanoylthreonine phosphate as terminal electron acceptor. The heterodisulfide and methane are formed in the methyl coenzyme M reductase reaction. The reducing equivalents are derived from reduced coenzyme F420, which represents an analogue of NADH + H+ in other respiratory chains. It is assumed that the proton-translocating oxidoreductase discovered in strain Go1 is of principal importance to all Methanogenic bacteria not utilizing H2.
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ATP synthesis coupled to electron transfer from H2 to the heterodisulfide of 2-mercaptoethanesulfonate and 7-mercaptoheptanoylthreonine phosphate in vesicle preparations of the Methanogenic Bacterium strain Gö1
FEBS Letters, 1990Co-Authors: Susanne Peinemann, Rudolf K Thauer, Michael Blaut, Reiner Hedderich, Gerhard GottschalkAbstract:Abstract Crude vesicle preparations of the Methanogenic strain Gol were able to couple the reduction of the heterodisulfide of 2-mercaptoethanesulfonate and 7-mercaptoheptanoylthreonine phosphate (CoM- S - S -HTP) by H 2 with ATP formation. The rate of ATP synthesis was 1 nmol min mg protein. ATP synthesis and disulfide reduction were only observed with CoM- S - S -HTP, but not with CoM- S - S -CoM or HTP- S - S -HTP. The methylreductase inhibitor 2-bromoethanesulfonic acid had no effect on ATP synthesis induced by CoM- S - S -HTP reduction with H 2 . ATP synthesis was completely inhibited by the uncoupler SF 6847 whereas the concomitant CoM- S - S -HTP reduction was stimulated. The ATP synthase inhibitors DCCD and DES also inhibited ATP formation completely and decreased the CoM- S - S -HTP reduction rate to 35% of the control. These inhibitory effects were abolished by addition of the uncoupler. From these results it is concluded that energy coupling between the electron transfer from H 2 to the heterodisulfide and ATP synthesis occurs via a transmembrane proton gradient.
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Membrane-bound F420H2-dependent heterodisulfide reductase in Methanogenic Bacterium strain Göl and Methanolobus tindarius
FEBS Letters, 1990Co-Authors: Uwe Deppenmeier, Michael Blaut, Andreas Mahlmann, Gerhard GottschalkAbstract:Abstract Washed membrane or cytoplasmic fractions of the Methanogenic Bacterium strain Gol catalyzed the oxidation of coenzyme F420H2 with a variety of electron acceptors. The F420H2-oxidizing activity of the cytoplasmic fraction could be assigned to a NADP+:F420 oxidoreductase. The membrane fraction but not the cytoplasmic fraction catalyzed the oxidation of F420H2 with the concomitant reduction of the heterodisulfide of 2-mercapto-ethanesulfonate and 7-mercaptoheptanoylthreonine phosphate (CoM-S-S-HTP) at a rate of 100 nmol min-mg protein according to the following equation: F420H2+CoM-S-S-HTP → F420 + CoM + HTP-SH. The activity depended linearly on the membrane protein up to a concentration of 60 μg ml The physiological electron acceptor CoM-S-S-HTP could not be replaced by the corresponding homodisulfides CoM-S-S-CoM and HTP-S-S-HTP or by NADP+. A membrane-bound F420H2-dependent CoM-S-S-HTP reductase was also detected in Methanolobus tindarius exhibiting a specific activity of 75 nmol min m g protein. The absence of a F420-dependent hydrogenase in this organism excludes the involvement of this enzyme in electron transfer from H420H2 to CoM-S-S-HTP.
Michael Blaut - One of the best experts on this subject based on the ideXlab platform.
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Transformation of tetrachloroethylene to trichloroethylene by homoacetogenic bacteria
FEMS microbiology letters, 1994Co-Authors: Detlef P. Terzenbach, Michael BlautAbstract:Eight homoacetogenic strains of the genera AcetoBacterium, Clostridium and Sporomusa were tested for their ability to dechlorinate tetrachloroethylene (perchloroethene, PCE). Of the organisms tested only Sporomusa ovata was able to reductively dechlorinate PCE with methanol as an electron donor. Resting cells of S. ovata reductively dechlorinated PCE at a rate of 9.8 nmol h−1 (mg protein)−1 to trichloroethylene (TCE) as the sole product. The dechlorination activity depended on concomitant acetogenesis from methanol and CO2. Cell-free extracts of S. ovata, Clostridium formicoaceticum, AcetoBacterium woodii, and the Methanogenic Bacterium Methanolobus tindarius transformed PCE to TCE with Ti(III) or carbon monoxide as electron donors. Corrinoids were shown in S. ovata to be involved in the dechlorination reaction of PCE to TCE as evident from the reversible inhibition with propyl iodide. Rates of dechlorination followed a pseudo-first-order kinetic.
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H2: heterodisulfide oxidoreductase, a second energy-conserving system in the Methanogenic strain Gö1
Archives of Microbiology, 1991Co-Authors: Uwe Deppenmeier, Michael Blaut, Gerhard GottschalkAbstract:Washed everted vesicles of the Methanogenic Bacterium strain Go1 catalyzed an H2-dependent reduction of the heterodisulfide of HS-CoM (2-mercaptoethanesulfonate) and HS-HTP (7-mercaptoheptanoylthreonine phosphate) (CoM-S-S-HTP). This process was independent of coenzyme F420 and was coupled to proton translocation across the cytoplasmic membrane into the lumen of the everted vesicles. The maximal H+/CoM-S-S-HTP ratio was 2. The tranmembrane electrochemical gradient thereby generated was shown to induce ATP synthesis from ADP+Pi, exhibiting a stoichiometry of 1 ATP synthesized per 2 CoM-S-S-HTP reduced (H+/ATP=4). ATP formation was inhibited by the uncoupler 3,5-di-tert-butyl-4-hydroxy-benzylidene-malononitrile (SF 6847) and by the ATP synthase inhibitor N,N′-dicyclohexylcarbodiimide (DCCD). This energy-conserving system showed a stringent coupling. The addition of HS-CoM and HS-HTP at 1 mM each decreased the heterodisulfide reductase activity to 50% of the control. Membranes from Methanolobus tindarius showed F420H2-dependent but no H2-dependent heterodisulfide oxidoreductase activity. Neither of these activities was detectable in membranes of Methanococcus thermolithotrophicus.
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Reduced coenzyme F420: heterodisulfide oxidoreductase, a proton- translocating redox system in Methanogenic bacteria.
Proceedings of the National Academy of Sciences of the United States of America, 1990Co-Authors: Uwe Deppenmeier, Michael Blaut, Andreas Mahlmann, Gerhard GottschalkAbstract:Abstract Washed everted vesicles of the Methanogenic Bacterium strain Go1 were found to couple the F420H2-dependent heterodisulfide reduction with the transfer of protons across the membrane into the lumen of the everted vesicles. The transmembrane electrochemical potential of protons thereby generated was shown to be competent in driving ATP synthesis from ADP + Pi, exhibiting a stoichiometry of 2 H+ translocated or 0.4 ATP synthesized per F420H2 oxidized. This enzyme system exhibits the phenomenon of coupling and uncoupling and represents a different kind of electron transport chain with the heterodisulfide of 2-mercaptoethanesulfonate and 7-mercaptoheptanoylthreonine phosphate as terminal electron acceptor. The heterodisulfide and methane are formed in the methyl coenzyme M reductase reaction. The reducing equivalents are derived from reduced coenzyme F420, which represents an analogue of NADH + H+ in other respiratory chains. It is assumed that the proton-translocating oxidoreductase discovered in strain Go1 is of principal importance to all Methanogenic bacteria not utilizing H2.
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ATP synthesis coupled to electron transfer from H2 to the heterodisulfide of 2-mercaptoethanesulfonate and 7-mercaptoheptanoylthreonine phosphate in vesicle preparations of the Methanogenic Bacterium strain Gö1
FEBS Letters, 1990Co-Authors: Susanne Peinemann, Rudolf K Thauer, Michael Blaut, Reiner Hedderich, Gerhard GottschalkAbstract:Abstract Crude vesicle preparations of the Methanogenic strain Gol were able to couple the reduction of the heterodisulfide of 2-mercaptoethanesulfonate and 7-mercaptoheptanoylthreonine phosphate (CoM- S - S -HTP) by H 2 with ATP formation. The rate of ATP synthesis was 1 nmol min mg protein. ATP synthesis and disulfide reduction were only observed with CoM- S - S -HTP, but not with CoM- S - S -CoM or HTP- S - S -HTP. The methylreductase inhibitor 2-bromoethanesulfonic acid had no effect on ATP synthesis induced by CoM- S - S -HTP reduction with H 2 . ATP synthesis was completely inhibited by the uncoupler SF 6847 whereas the concomitant CoM- S - S -HTP reduction was stimulated. The ATP synthase inhibitors DCCD and DES also inhibited ATP formation completely and decreased the CoM- S - S -HTP reduction rate to 35% of the control. These inhibitory effects were abolished by addition of the uncoupler. From these results it is concluded that energy coupling between the electron transfer from H 2 to the heterodisulfide and ATP synthesis occurs via a transmembrane proton gradient.
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Membrane-bound F420H2-dependent heterodisulfide reductase in Methanogenic Bacterium strain Göl and Methanolobus tindarius
FEBS Letters, 1990Co-Authors: Uwe Deppenmeier, Michael Blaut, Andreas Mahlmann, Gerhard GottschalkAbstract:Abstract Washed membrane or cytoplasmic fractions of the Methanogenic Bacterium strain Gol catalyzed the oxidation of coenzyme F420H2 with a variety of electron acceptors. The F420H2-oxidizing activity of the cytoplasmic fraction could be assigned to a NADP+:F420 oxidoreductase. The membrane fraction but not the cytoplasmic fraction catalyzed the oxidation of F420H2 with the concomitant reduction of the heterodisulfide of 2-mercapto-ethanesulfonate and 7-mercaptoheptanoylthreonine phosphate (CoM-S-S-HTP) at a rate of 100 nmol min-mg protein according to the following equation: F420H2+CoM-S-S-HTP → F420 + CoM + HTP-SH. The activity depended linearly on the membrane protein up to a concentration of 60 μg ml The physiological electron acceptor CoM-S-S-HTP could not be replaced by the corresponding homodisulfides CoM-S-S-CoM and HTP-S-S-HTP or by NADP+. A membrane-bound F420H2-dependent CoM-S-S-HTP reductase was also detected in Methanolobus tindarius exhibiting a specific activity of 75 nmol min m g protein. The absence of a F420-dependent hydrogenase in this organism excludes the involvement of this enzyme in electron transfer from H420H2 to CoM-S-S-HTP.
Jean-louis Garcia - One of the best experts on this subject based on the ideXlab platform.
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methanoBacterium congolense sp nov from a Methanogenic fermentation of cassava peel
International Journal of Systematic and Evolutionary Microbiology, 2001Co-Authors: Nadine Cuzin, Aboubakar S. Ouattara, Marc Labat, Jean-louis GarciaAbstract:Strain CT, a non-motile, mesophilic, hydrogenotrophic, Methanogenic Bacterium, was isolated from an anaerobic digester used for the treatment of raw cassava-peel waste in Congo. The cells were rods, 0.4-0.5 x 2-10 microm in size, and stained Gram-positive. Hydrogen and carbon dioxide were the only substrates that supported growth and methane production. Methane production, but not growth, occurred with CO2 in the presence of either 2-propanol, 2-butanol or cyclopentanol as hydrogen donors. The temperature range for growth was 25-50 degrees C, the optimum being between 37 and 42 degrees C. The optimum pH for growth was 7.2; consistent growth and methane production were not observed below pH 5.9 or above pH 8.2. The doubling time under optimal growth conditions was 7.5 h. The DNA base composition was 39.5 mol% G+C. On the basis of 16S rRNA gene sequence analysis and phenotypic characteristics, the isolate is proposed as a new species of the genus MethanoBacterium, namely MethanoBacterium congolense sp. nov. The type strain is strain CT (= DSM 7095T = OCM 779T).
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methanoBacterium oryzae sp nov a novel Methanogenic rod isolated from a philippines ricefield
International Journal of Systematic and Evolutionary Microbiology, 2000Co-Authors: Catherine Joulian, Jean-louis Garcia, B K C Patel, Bernard Ollivier, Pierre RogerAbstract:A rod (0.3-0.4 micron x 3-10 microns) to filamentous (up to 40 microns) non-motile Methanogenic Bacterium, designated strain FPiT (T = type strain), was isolated from ricefield soil in the Philippines. The strain uses H2 + CO2 or formate for growth and produces CH4. Optimum growth temperature is 40 degrees C; no growth is observed at 15 degrees C or 45 degrees C. Optimum pH for growth is 7; no growth is observed at pH 5.5 or 9.0. Strain FPiT is halotolerant and grows at NaCl concentrations of 0-25 g l-1. The G + C content of its DNA is 31 mol%. Based on 16S rRNA gene sequence analysis, the isolate was identified as a new species of the genus MethanoBacterium: MethanoBacterium oryzae sp. nov. The type strain is FPiT (= DSM 11106T).
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Methanoplanus petrolearius sp. nov., a novel Methanogenic Bacterium from an oil-producing well
FEMS microbiology letters, 1997Co-Authors: Bernard Ollivier, Jean-luc Cayol, Bharat K. C. Patel, Michel Magot, Marie-laure Fardeau, Jean-louis GarciaAbstract:A disc-shaped Methanogenic Bacterium designated strain SEBR 4847T (T=type strain) was isolated from a sample collected from an African offshore oil field. Strain SEBR 4847T was non-motile, had a G+C content of 50 mol% and produced methane from H2+CO2, formate, and CO2+propanol. Strain SEBR 4847T grew optimally at 37°C; no growth was observed at 25°C or 45°C. It grew in the presence of up to 50 g/l NaCl; 10–30 g/l was required for optimal growth. The optimum pH for growth was 7.0. Doubling time was about 10 h under optimal conditions. Based on 16S rRNA sequence analysis, the isolate was identified as a new species of the genus Methanoplanus and designated Methanoplanus petrolearius sp. nov. The type strain is SEBR 4847T (=OCM 486).
Ramaraj Boopathy - One of the best experts on this subject based on the ideXlab platform.
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Methanogenic transformation of methylfurfural compounds to furfural.
Applied and environmental microbiology, 1996Co-Authors: Ramaraj BoopathyAbstract:The metabolic conversion of 5-methylfurfural and 2-methylfurfural to furfural by a Methanogenic Bacterium, Methanococcus sp. strain B, was studied. This Bacterium was found to use methylfurfural compounds as a growth substrate and to convert them stoichiometrically to furfural. For every mole of methylfurfurals metabolized, almost 1 mol of furfural and 0.7 mol of methane were produced. Several Methanogenic bacteria did not carry out this conversion. The metabolic conversion of methylfurfurals is likely to be of value in the anaerobic treatment of methylfurfural-containing wastewaters such as those produced by the paper and pulp industries and oatmeal processing industries. This study adds to the list of the limited number of compounds that are known to serve as electron donors for methanogenesis.
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Isolation and characterization of a Methanogenic Bacterium from swine manure
Bioresource Technology, 1996Co-Authors: Ramaraj BoopathyAbstract:Abstract A mesophilic, Gram positive (Gram +ve), irregular coccoid methanogen, which showed close resemblance to a Methanosarcina sp., was isolated from swine manure. Acetate or methanol or H 2 + CO 2 served as a substrate for methanogenesis in a mineral salt medium. The isolate did not use formate as a growth substrate. The organism had an optimum pH of 6.8 and an optimum temperature of 37°C. The isolate used ammonia as a nitrogen source. The role of this methanogen in the swine manure is the terminal oxidation of simple organic compounds like acetate to CO 2 and methane. In an earlier report, a sulfate-reducing Bacterium (SRB) isolated from swine manure that converted phenol to acetic acid was described (Boopathy, 1995). The methanogen described in this paper was isolated from the same swine manure sample. In a microbial ecology scenario these two anaerobic bacteria (methanogen and SRB) could co-exist together and degrade phenol to CO 2 and methane.
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Transformation of nitroaromatic compounds by a Methanogenic Bacterium, Methanococcus sp. (strain B)
Archives of Microbiology, 1994Co-Authors: Ramaraj BoopathyAbstract:The transformation of several nitroaromatic compounds by a newly isolated Methanogenic Bacterium, Methanococcus sp. (strain B) was studied. The presence of nitroaromatic compounds (0.5 mM) viz., nitrobenzene, 2,4-dinitrobenzene, 2,4,6-trinitrobenzene, 2,4-dinitrophenol, 2,4-dinitrobenzene, and 2,6-dinitrotoluene in the culture medium did not inhibit growth of the isolate. The bacteria grew rapidly and reached stationary phase within seven days of incubation. All the nitroaromatic compounds tested were 80 to 100% transformed by the Bacterium to amino compounds by a reduction process. The isolate did not use the nitroaromatic compounds as the sole source of carbon or nitrogen. The transformation of nitroaromatic compounds by this isolate was compared to that of other Methanogenic bacteria. Out of five methanogens studied, only Methanococcus deltae and Methanococcus thermolithotrophicus could transform the nitroaromatic compounds; however, the transformation rates were significantly less than that of the new isolate Methanococcus sp. (strain B). The nitroaromatic compounds were not transformed by Methanosarcina barkeri, MethanoBacterium thermoautotrophicum , and Methanobrevibacter ruminantium .
April B. Leytem - One of the best experts on this subject based on the ideXlab platform.
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The characterization of microorganisms in dairy wastewater storage ponds.
Journal of environmental quality, 2013Co-Authors: Robert S. Dungan, April B. LeytemAbstract:Dairy wastewaters from storage ponds are commonly land applied to irrigate forage crops. Given that diverse microbial populations are associated with cattle feces, the objective of this study was to use a culture-independent approach to characterize bacteria and archaea in dairy wastewaters. Using domain-specific primers, a region of the 16S rRNA gene was amplified from pooled DNA extracts from 30 dairy wastewaters and subsequently used to create a clone library. A total of 152 bacterial clones were examined and sequence matches were affiliated with the following groups: Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, and Synergistetes. Firmicutes was identified as the largest phylum, representing up to 69% of the clone sequences. Of 167 clones representing Archaea, seven genera were found to be closely related (91-100% sequence similarity) to isolates obtained from sediments and feces. Most of the putative sequence matches (98%) represented members from the class Methanomicrobia. With respect to the archaeal clones, only one of the putative sequence matches was affiliated with a Methanogenic Bacterium known to inhabit the rumen.