Previous Article | Next Article ![]()
J. Bacteriol., 04 1995, 2002-2007, Vol 177, No. 8
AK Bock and P Schonheit
A mutant of Methanosarcina barkeri (Fusaro) is able to grow on pyruvate as
the sole carbon and energy source. During growth, pyruvate is converted to
CH4 and CO2, and about 1.5 mol of ATP per mol of CH4 is formed (A.-K. Bock,
A. Prieger-Kraft, and P. Schonheit, Arch. Microbiol. 161:33-46, 1994). The
pyruvate-utilizing mutant of M. barkeri could also grow on pyruvate when
methanogenesis was completely inhibited by bromoethanesulfonate (BES). The
mutant grew on pyruvate (80 mM) in the presence of 2 mM BES with a doubling
time of about 30 h up to cell densities of about 400 mg (dry weight) of
cells per liter. During growth on pyruvate, the major fermentation products
were acetate and CO2 (about 0.9 mol each per mol of pyruvate). Small
amounts of acetoin, acetolactate, alanine, leucine, isoleucine, and valine
were also detected. CH4 was not formed. The molar growth yield (Yacetate)
was about 9 g of cells (dry weight) per mol of acetate, indicating an ATP
yield of about 1 mol/mol of acetate formed. Growth on pyruvate in the
presence of BES was limited; after six to eight generations, the doubling
times increased and the final cell densities decreased. After 9 to 11
generations, growth stopped completely. In the presence of BES, suspensions
of pyruvate-grown cells fermented pyruvate to acetate, CO2, and H2. CH4 was
not formed. Conversion of pyruvate to acetate, in the complete absence of
methanogenesis, was coupled to ATP synthesis. Dicyclohexylcarbodiimide, an
inhibitor of H(+)-translocating ATP synthase, did not inhibit ATP
formation.(ABSTRACT TRUNCATED AT 250 WORDS)
Copyright © 1995, American Society for Microbiology
Growth of Methanosarcina barkeri (Fusaro) under nonmethanogenic conditions by the fermentation of pyruvate to acetate: ATP synthesis via the mechanism of substrate level phosphorylation
Institut fur Pflanzenphysiologie und Mikrobiologie, Fachbereich Biologie, Freie Universitat Berlin, Germany.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»