Effect of the activity of primary proton pumps on the growth of Escherichia coli in the presence of acetate
Smirnova, G.V.; Oktiabr'skiĭ, O.N.
Mikrobiologiia 57(4): 554-559
1988
ISSN/ISBN: 0026-3656 PMID: 2905416 Document Number: 320155
Escherichia coli batch cultures were grown under aerobic and anaerobic conditions on glucose with the substrate addition at pH 7.0. The cultures accumulated acetate in the medium at concentrations sufficient to inhibit the growth. This inhibitory effect of acetate was mediated apparently via its action on the intracellular pH. The inhibition of E. coli growth by acetate increased when the redox proton pump was switched off in the course of transition from aerobiosis to anaerobiosis and when the regulation of K+ fluxes was disordered in the presence of valinomycin. H+-ATPase was not essentially involved in maintaining the high rate of E. coli growth in the presence of acetate under aerobic conditions. If the activity of H+-ATPase was inhibited under anaerobic conditions at pH 7.0, the growth ceased after the dissipation of ionic gradients on the membrane. When CCCP was added under aerobic conditions, the growth did not stop at once if the medium had a pH of 7.6, but ceased immediately at pHout 7.0 in the glucose-salt medium.