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Stabilization of delta mu H+ in Escherichia coli upon K+ and Na+ transmembrane gradient dissipation

, : Stabilization of delta mu H+ in Escherichia coli upon K+ and Na+ transmembrane gradient dissipation. Biokhimiia 47(1): 137-144

The role of Na+/K+ gradients as a stabilizing factor for the energetics of bacterial cell has been evaluated. It was shown that in the presence of a Na+/K+ gradient across the membrane the cells of the unc mutant of E. coli retain their motility for some time under anaerobic conditions. This time coincides with that of dissipation of the K+ gradient by the bacteria during the anaerobiosis. A switch-off of the generator (respiration) entails a collapse of the membrane potential (delta psi). The anaerobiosis-induced efflux of K+ from the cells is uncoupler-stimulated, thus suggesting that the K+ efflux has an electrogenic nature and stabilizes delta psi. The use of valinomycin allowed to establish a correlation between the rate of K+ efflux, the delta psi value and the rate of bacterial motion under anaerobic conditions. After the onset of anaerobiosis the level of delta psi decreases faster as the concentration of extracellular K+ increases. It was shown that the capacity of the K+ gradient as te delta psi buffer depends on the pH of the medium and that artificial Na+ gradient can energize the E. coli cells by Na+/K+ exchange.


PMID: 7039692

Other references

Yokoji M.; Kawamura R.; Yokoyama M.; Okuno M.; Harada Y., 1991: Four cases of fluctuating perceptive deafness associated with behcets disease. Audiology Japan 34(5): 483-484

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Loedorff, C.J., 1967: Studies on the life-history and distribution in South Africa of Chironomus (Chironomus) transvaalensis Kieffer. Publications University Pretoria (NR). 1963-1964 ; 40: 87-88

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Kokes O., 1970: The white stork in the central flow of the elbe river up to 1964. Ziva 18(3): 112-113