EFFECT OF METABOLIC ACTIVITY OF THE GLUCOSE PERMEASE OF BACTERIAL CELLS

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Abstract
The ([alpha] methyl-glucoside) (gamma MG) accumulating system of both Salmonella typhimurium and Escherichia coli and the [beta]-galactoside and galactose accumulating systems of E. coli differ. Active respiratory activity accompanied by oxidative phosphorylation depresses the steady-state level of aMG accumulated within the cells. The level attained during the oxidation of an exogenously supplied substrate can be increased by the addition of dinitrophenol or azide at suitable concentrations. The aMG accumulation is greater when the cells depend for their energy supply on endogenous respiration or on the anaerobic fermentation of an exogenous substrate rather than on the active oxidation of such a substrate in the absence of poisons. The agents or sites for the exit and entry reactions require adenosine-triphosphate (ATP) for their activity, but the former become saturated at higher levels of ATP than do the latter. An increase in the level of ATP available to the cell is indicated by the relative increase in the rate of exit as compared with that of entry for any given internal and external concentrations of the accumulated substrate.