H+-K+-exchange in anaerobically grown Escherichia coli bacteria during use of various sugars as exogenous energy sources
Trchunian, A.A.; Ogandzhanian, E.S.
Biofizika 43(1): 82-86
1998
ISSN/ISBN: 0006-3029 PMID: 9567180 Document Number: 492694
E.coli bacteria, grown in anaerobic conditions, in the medium with glucose, lactose or maltose, upon transferring into a fresh medium with the same sugar acidify it and accumulate potassium ions with a fixed stoichiometry for the N,N'-dicyclohexylcarbodiimide-inhibited cation fluxes, which is equal to 2H+ of the cytoplasm per one K+ of the medium. Such an H(+)-K(+)-exchange is sensitive to osmotic shock. In the medium with lactose or maltose cation fluxes are less and the intracellular K+ activity at the moment of maximal accumulation is lower. The H(+)-K(+)-exchange with a variable stoichiometry of cation fluxes is lost in bacteria, grown in a medium with lactose or maltose.