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Acetate catabolism by Methanosarcina barkeri : Hydrogen-dependent methane production from acetate by a soluble cell protein fraction

1984; Oxford University Press; Volume: 25; Issue: 1 Linguagem: Inglês

10.1111/j.1574-6968.1984.tb01369.x

1574-6968

Joseph A. Krzycki, J. G. Zeikus,

Biofuel production and bioconversion

Cell extracts prepared from Methanosarcina barkeri converted acetate into methane and carbon dioxide under a hydrogen atmosphere. Methanogenesis by cell extracts required acetate and ATP and, the in vitro rate was 5 to 10% of the rate of methanogenesis observed during exponential growth of cells on acetate. Methane and carbon dioxide produced by cell extracts originated predominantly from the methyl and carboxyl groups of acetate, respectively, in a manner consistent with that observed in whole cells. Acetate degradation activity was detected in the soluble (150000 ×g supernatant) fraction and not in the membrane fraction. These results are discussed in relation to a proposed model for ATP generation from acetate that involves both membrane-bound and soluble enzymatic components such as CO dehydrogenase.