Action of Amino Acids on Bacterial Dehydrogenases and Glycolysis

Abstract

Summary

Amino acids, aerobically and anaerobically, cause an acceleration of the reduction of tetrazolium by Micrococcus pyogenes var. aureus in the presence of glucose, and can be shown to shift glucose metabolism towards increased lactate production. This effect of amino acids appears to be related to the inhibition of normally occurring reactions resulting in an increased availability of hydrogen for the reduction of tetrazolium or pyruvate.

Oxygen inhibits the reduction of tetrazolium in the absence of added amino acids, while sulfathiazole inhibits the amino acid accelerated reduction of tetrazolium. Since flavoprotein is reported to mediate tetrazolium reduction and to be susceptible to inhibition by sulfathiazole, the accelerative effect of amino acids on the reduction of tetrazolium could be related to an interaction of the amino acids with the flavoprotein enzyme. Competition for this enzyme site between tetrazolium, oxygen and pyruvate, modified by the presence of amino acids and sulfathiazole is suggested as an explanation consistent with the observed accelerations and inhibitions of the reduction of tetrazolium.