Hydrogenase Measurement with Photochemically Reduced Methyl Viologen

Yu, L.; Wolin, M. J.

doi:10.1128/jb.98.1.51-55.1969

Cited by 52 publications

(17 citation statements)

References 10 publications

(4 reference statements)

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“…Reaction rates were measured with a Beckman DK2 recording spectrophotometer at 600nm. A molar absorption coefficient of 8250 litre mol-' cm-' was used (Yu & Wolin, 1969). The reduction of 2mol of Methyl Viologen equals the consumption of 1 mol of H2.…”

Section: Results and Discussion Distribution Ofhydrogenase Activitymentioning

confidence: 99%

Methane synthesis without the addition of adenosine triphosphate by cell membranes isolated from Methanobacterium ruminantium

Sauer¹,

Erfle²,

Mahadevan³

1979

Biochemical Journal

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The membrane fraction isolated from broken cells of Methanobacterium ruminantium actively synthesized methane from CO2 and H2 without the addition of ATP or other cofactors. This activity was lost unless strictly anaerobic conditions were maintained throughout the isolation and incubation procedures. 3H2, but not 3H2O, was readily incorporated into methane. This indicates that hydrogen atoms are used in the formation of methane without the prior equilibration of protons with the water phase. Methylenetetrahydrofolate was shown to be converted into methane, but less efficiently than CO2. The evidence indicates that tetrahydrofolate derivatives may not be of primary importance in the formation of methane from CO2 and H2. No requirement for ATP in methanogenesis could be demonstrated. However, chemical reagents that can increase proton conductance in membranes and therby abolish the membrane electrical potential were also effective inhibitors of methanogenesis. It was postulated that, although the reduction of CO2 to methane by bacterial membranes may require energy derived from a transmembrane potential, this does not appear to be coupled to the intermediary synthesis of ATP.

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Section: Results and Discussion Distribution Ofhydrogenase Activitymentioning

confidence: 99%

Methane synthesis without the addition of adenosine triphosphate by cell membranes isolated from Methanobacterium ruminantium

Sauer¹,

Erfle²,

Mahadevan³

1979

Biochemical Journal

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“…Enzymatic reduction of NAD with formate was followed in a similar manner except that anaerobic conditions were used. The Thunberg cuvettes and contents were flushed ten times with oxygen-free N2 gas (22).…”

Section: Methodsmentioning

confidence: 99%

Ferredoxin- and Nicotinamide Adenine Dinucleotide-Dependent H ₂ Production from Ethanol and Formate in Extracts of S Organism Isolated from “Methanobacillus omelianskii”

1972

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S organism ferments ethanol to acetate and H 2 but grows poorly on ethanol unless the partial pressure of H 2 is kept low, as when it is grown in combination with an H 2 -utilizing methanogenic bacterium. The present study shows that S organism contains an alcohol dehydrogenase and a formate dehydrogenase, both of which require nicotinamide adenine dinucleotide (NAD) for activity. Hydrogen is evolved from NADH generated by these activities via a ferredoxin-dependent oxidation of NADH to NAD and H 2 . NADH:NADP oxido-reductase activity was also demonstrated. The relationship of these activities to the growth of S organism is discussed.

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“…In the general assay, conventional Warburg techniques at 37 C were used and the standard reaction mixture (total volume 3.0 ml) contained in Mmoles: Tris buffer (pH 8.0), 300; MgCl2, 10; reduced glutathione (GSH), 10; and extract plus appropriate acceptor. Vessels were gassed for 15 min with oxygen-free hydrogen gas which was obtained by passing it through a column of hot reduced copper wire and two 500-ml gas washing bottles containing photochemically reduced methyl viologen (17). After gassing, the vessels were incubated for 10 min and the reaction was started by tipping in GSH plus appropriate cell-free extract from the side arm.…”

mentioning

confidence: 99%

Factor 420-dependent tyridine nucleotide-linked hydrogenase system of Methanobacterium ruminantium

Tzeng¹,

Wolfe²,

Bryant³

1975

J Bacteriol

106

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Methanobacterium ruminantium was shown to possess a nicotinamide adenine dinucleotide phosphate (NADP)-linked factor 420 (F420)-dependent hydrogenase system. This system was also shown to be present in Methanobacterium strain MOH. The hydrogenase system of M. ruminantium also links directly to F,20, flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), methyl viologen, and Fe3+. It has a pH optimum of about 8 and an apparent Km for F,20 of about 5 x 10-6 M at pH 8 when NADP is the electron acceptor. The F420-NADP oxidoreductase activity is inactive toward nicotinamide adenine dinucleotide (NAD) and no NADPH:NAD or FADH,(FMNH,):NAD transhydrogenase system was detected. Neither crude ferredoxin nor boiled crude extract of Clostridium pasteurianum could replace F420 in the NADP-linked hydrogenase reaction of M. ruminantium. Also, neither F,20 nor a crude "ferredoxin" fraction from M. ruminantium extracts could substitute for ferredoxin in the pyruvateferredoxin oxidoreductase reaction of C. pasteurianum. All known methanogenic bacteria may obtain energy from growth via unknown mechanisms involved in reduction of CO2 to methane using electrons generated in the oxidation of hydrogen (14, 16), but little information is available concerning electron transfer pathways for their utilization of molecular hydrogen.

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Hydrogenase Measurement with Photochemically Reduced Methyl Viologen

Cited by 52 publications

References 10 publications

Methane synthesis without the addition of adenosine triphosphate by cell membranes isolated from Methanobacterium ruminantium

Methane synthesis without the addition of adenosine triphosphate by cell membranes isolated from Methanobacterium ruminantium

Ferredoxin- and Nicotinamide Adenine Dinucleotide-Dependent H ₂ Production from Ethanol and Formate in Extracts of S Organism Isolated from “Methanobacillus omelianskii”

Factor 420-dependent tyridine nucleotide-linked hydrogenase system of Methanobacterium ruminantium

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Hydrogenase Measurement with Photochemically Reduced Methyl Viologen

Cited by 52 publications

References 10 publications

Methane synthesis without the addition of adenosine triphosphate by cell membranes isolated from Methanobacterium ruminantium

Methane synthesis without the addition of adenosine triphosphate by cell membranes isolated from Methanobacterium ruminantium

Ferredoxin- and Nicotinamide Adenine Dinucleotide-Dependent H 2 Production from Ethanol and Formate in Extracts of S Organism Isolated from “Methanobacillus omelianskii”

Factor 420-dependent tyridine nucleotide-linked hydrogenase system of Methanobacterium ruminantium

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Ferredoxin- and Nicotinamide Adenine Dinucleotide-Dependent H ₂ Production from Ethanol and Formate in Extracts of S Organism Isolated from “Methanobacillus omelianskii”