Sodium dependence of acetate formation by the acetogenic bacterium Acetobacterium woodii.
Growth of Acetobacterium woodii on fructose was stimulated by Na+; this stimulation was paralleled by a shift of the acetate-fructose ratio from 2.1 to 2.7. Growth on H2-CO2 or on methanol plus CO2 was strictly dependent on the presence of sodium ions in the medium. Acetate formation from formaldehyde plus H2-CO by resting cells required Na+, but from methanol plus H2-CO did not. This is analogous to H2-CO2 reduction to methane by Methanosarcina barkeri, which involves a sodium pump (V. Müller, C. Winner, and G. Gottschalk, Eur. J. Biochem. 178:519-525, 1988). This suggests that the reduction of methylenetetrahydrofolate to methyltetrahydrofolate is the Na+-requiring reaction. A sodium gradient (Na+ out/Na+ in = 32, delta pNa = -91 mV) was built up when resting cells of A. woodii were incubated under H2-CO2. Acetogenesis was inhibited when the delta pNa was dissipated by monensin.
Heise
R
R
Institut für Mikrobiologie der Universität Göttingen, Federal Republic of Germany.
Müller
V
V
Gottschalk
G
G
D000085:Acetates / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D005632:Fructose / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D000432:Methanol / Q000378:metabolism; D008985:Monensin / Q000494:pharmacology; D009584:Nitrogen / Q000378:metabolism; D012964:Sodium / Q000502:physiology*
D000085:Acetates; D002245:Carbon Dioxide; D005632:Fructose; D008985:Monensin; D012964:Sodium; D009584:Nitrogen; D000432:Methanol