Methane as a Minor Product of Pyruvate Metabolism by Sulphate-reducing and Other Bacteria

Abstract

SUMMARY: Disrupted cells of some Desulfovibrio species, of Desulfotomaculum ruminis and of certain other anaerobes produced methane as a minor product of pyruvic phosphoroclasm. In one Desulfovibrio species the reaction, which was not specially sensitive to air, involved vitamin B12, co-enzyme A, thiamine pyrophosphate, magnesium ions and acetyl phosphate. Adenine and other nucleotides stimulated the reaction; a mixture of ATP and AMP was most effective. Methionine stimulated the reaction but the other methyl donors did not. In optimal conditions methane accounted for 0.1 to 0.02 mole % of the pyruvate metabolized, formed at 20 to 30 nl. CH4/mg. bacterial protein/hr. Tests in D2O indicated that the methane came from the methyl-carbon of pyruvate; correspondingly, ethane formation from α-ketobutyrate was detected.