Methane biosynthesis by Methanosarcina barkeri

Blaylock, Barbara A.; Stadtman, Thressa C.

doi:10.1016/0003-9861(66)90022-1

Cited by 71 publications

(15 citation statements)

References 17 publications

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“…Methanosarcina barkeri (DSM 800) was grown at 37 "C in a medium as previously described [33]. The cells were harvested by centrifugation at the end of the growth phase and stored at -25°C.…”

Section: Growth Of the Microorganism And Preparation Of The Crude Extmentioning

confidence: 99%

Purification, characterization and redox properties of hydrogenase from Methanosarcina barkeri (DSM 800)

Fauque

Teixeira²,

Moura³

et al. 1984

European Journal of Biochemistry

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A soluble hydrogenase from the methanogenic bacterium, Methanosarcina barkeri (DSM 800) has been purified to apparent electrophoretic homogeneity, with an overall 550-fold purification, a 45 % yield and a final specific activity of 270 pmol H2 evolved min-' (mg protein)-'. The hydrogenase has a high molecular mass of z 800 kDa and subunits with molecular masses of z 60 kDa. The enzyme is stable to heating at 65 "C and to exposure to air at 4°C in the oxidized state for periods up to a week. The overall stability of this enzyme is compared with other hydrogenase isolated from strict anaerobic sulfate-reducing bacteria. Ms. barkeri hydrogenase shows an absorption spectrum typical of a non-heme iron protein with maxima at 275 nm, 380 nm and 405 nm. A flavin component, identified as FMN or riboflavin was extracted under acidic conditions and quantified to approximately one flavin molecule per subunit. In addition to this component, 8 -10 iron atoms and 0.6-0.8 nickel atom were also detected per subunit.The electron paramagnetic resonance (EPR) spectrum of the native enzyme shows a rhombic signal with g values at 2.24,2.20 and = 2.0. probably due to nickel which is optimally measured at 40 K but still detectable at 77 K. In the reduced state, using dithionite or molecular hydrogen as reductants, at least two types of g= 1.94 EPR signals, due to iron-sulfur centers, could be detected and differentiated on the basis of power and temperature dependence. Center I has g values at 2.04, 1.90 and 1.86, while center I1 has g values at 2.08, 1.93 and 1.85. When the hydrogenase is reduced by hydrogen or dithionite the rhombic EPR species disappears and is replaced by other EPR-active species with g values at 2.33, 2.23, 2.12, 2.09, 2.04 and 2.00. These complex signals may represent different nickel species and are only obser\'able at temperatures higher than 20 K. In the native preparation, at high temperatures ( T > 35 K) or in partially red wed samples, a free radical due to the flavin moiety is observed. The EPR spectrum of reduced hydrogenase in 80 "/, Me2S0 presents an axial type of spectrum only detectable below 30 K.The methanogenic bacteria are strict anaerobic microorganisms that synthesize methane from a limited number of substrates (e. g. formate, acetate, methylamines, methanol, CO or C 0 2 and H2). They belong to a bacterial group designated as Archaebacteria which are only distantly related in the evolutionary scale to eukaryotes and the strictly anaerobic bacteria such as Clostridia and sulfate-reducing organisms [ 11. Supporting this clasification, they contain unusual cofactors not found in other organisms such as: coenzyme M [2], F420 [3], F342 [4], and F,,, [5,6,52] which may be isolated in a protein-bound form. In contrast, the amino acid sequence of Methanosarcina barkeri ferredoxin is quite similar to the clostridial type [7], but the evolutionary significance of this observation is not understood.Methanogens are basically chemoautotrophs in their metabolism and molecular hydrogen is often used as a subst...

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Section: Growth Of the Microorganism And Preparation Of The Crude Extmentioning

confidence: 99%

Purification, characterization and redox properties of hydrogenase from Methanosarcina barkeri (DSM 800)

Fauque

Teixeira²,

Moura³

et al. 1984

European Journal of Biochemistry

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“…Let us now turn to the problem of biological methane formation. It is well established by the investigations of Blaylock and Stadtman and of Wolfe and his associates that the formation of methane by bacteria involves a participation of corrinoid compounds (Stadtman & Blaylock, 1966;. The most abundant corrinoids that can be extracted with ethanol from whole cells of the most intensively studied species, Methanolbaillu8 omeliaunkii and Methano8arcinca barkeri, have been identified as the hydroxo and 5'-deoxyadenosyl derivatives of factor III, a cobalamin analogue containing 5'-hydroxybenzimidazole in place of 5,6-dimethylbenzimidazole (Lezius & Barker, 1965;A.…”

Section: Methylcobalamin +Homocysteine Cobalamin + Methioninementioning

confidence: 99%

“…The utilization of N5-methyltetrahydrofolate for methane formation obviously indicates a relation between this system and the N5-methyltetrahydrofolate-homocysteine methyltransferase of other organisms. In the Methano8arcina system, methanol can serve, not only as a substrate for methane formation, but also as a methyl donor to vitamin B128 with the formation of methylcobalamin (Blaylock & Stadtman, 1966). As in other similar reactions, vitamin B128 cannot be replaced by the more oxidized forms of the vitamin.…”

Section: Methylcobalamin +Homocysteine Cobalamin + Methioninementioning

confidence: 99%

Biochemical functions of corrinoid compounds. The sixth Hopkins memorial lecture

Barker¹

1967

Biochemical Journal

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“…I n anaerobic respiration the synthesis of reduced one-carbon compounds from CO, is a well known electron accepting process : the methane bacteria reduce CO, to methane [25,26], while the acetic acid Clostridia form acetate [27--301. But apparently they cannot assimilate CO, by such a reduction.…”

Section: N Clostridium Kluyveri As In Escherichia Coli [24]mentioning

confidence: 99%

The Synthesis of One‐Carbon Units from CO₂ in Clostridium kluyveri

Jungermann

Thauer

Decker

1968

European Journal of Biochemistry

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Clostridium kluyveri was grown (a) on standard media, in which alternately [14C]bicarbonate, [U-14C], [1-14C], and 2-14C]acetate plus ethanol were the labeled substrates, and (b) on standard media supplemented with either formate, glycine or serine, in which bicarbonate or formate were 14C-labeled. Adenine, guanine and methionine were isolated from the cells and degraded.(a) Carbon atoms 2 and 8 of the purines were found to be synthesized from CO, (about 70 O/,) and from the methyl group (about 2O0lO) and the carboxyl group (about loo/,) of acetate. The X-methyl group of methionine was shown to be derived almost equally from CO, (about 5O0iO) and from the two-carbon substrates, the methyl group of acetate accounting for about 3501, and the carboxyl group for about 15 ,lo.(b) The participation of CO, in the synthesis of the X-methyl group of methionine remained unaffected (about SO0/,) in the presence of serine, while it was decreased to below 5 0 / , in the presence of formate and increased to over 80 in the presence of glycine. The participation of formate was in the order of 55 01,.These data demonstrate that (1) two major competitive pathways for the synthesis of onecarbon units exist in Clostridium kluyveri : C,-Units are formed predominantly by a reduction of CO, and to a minor degree by a cleavage of serine, the usual pathway ((3,-serine = C,-acetate) and (2) the relative rates of the two pathways are controlled by the glycine requirement of the growing organism. [l] is a strict anaerobe growing on synthetic media with ethanol, acetate, and bicarbonate as the sole energy-and carbonsubstrates [2-41. Clostridium IcluyveriIts carbon assimilation is characterized by a high net CO, fixation. About 30°/, of the cell carbon is derived from CO,, about 70°/, from acetate [5]. It has been found that the reductive, ferredoxin-dependent carboxylation of acetyl CoA to pyruvate [6] leads to the synthesis of both amino acids [7-91 and carbohydrates [9-111. I n this paper it will be shown that in Clostridium kluyveri CO, and acetate are also incorporated into the X-methyl group of methionine and into the positions 2 and 8 of purines, CO, being the major, acetate the minor source of one carbon units. The CO, assimilation is unexpected, as normally the hydroxymethyl group of serine and the aminomethyl group of glycine, which in Clostridium kluyveri are derived from the methyl-and carboxyl group of acetate [7], are the only precursors of reduced one carbon units.Studies on the "CO," and the "acetate" pathway and their regulation will be presented.

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Methane biosynthesis by Methanosarcina barkeri

Cited by 71 publications

References 17 publications

Purification, characterization and redox properties of hydrogenase from Methanosarcina barkeri (DSM 800)

Purification, characterization and redox properties of hydrogenase from Methanosarcina barkeri (DSM 800)

Biochemical functions of corrinoid compounds. The sixth Hopkins memorial lecture

The Synthesis of One‐Carbon Units from CO₂ in Clostridium kluyveri

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Methane biosynthesis by Methanosarcina barkeri

Cited by 71 publications

References 17 publications

Purification, characterization and redox properties of hydrogenase from Methanosarcina barkeri (DSM 800)

Purification, characterization and redox properties of hydrogenase from Methanosarcina barkeri (DSM 800)

Biochemical functions of corrinoid compounds. The sixth Hopkins memorial lecture

The Synthesis of One‐Carbon Units from CO2 in Clostridium kluyveri

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The Synthesis of One‐Carbon Units from CO₂ in Clostridium kluyveri