A BACTERIOCIDAL EFFECT OF 2-DEOXY-D-GALACTOSE ON ESCHERICHIA COLI DUE TO INHIBITION OF AMINO SUGAR METABOLISM

Abstract

A bacteriocidal effect of 2-deoxy-D-galactose (dGal) in addition to the well known static effect was newly demonstrated on the basis of various physiological and biochemical events in Escherichia coli. Unlike D- galactose-induced lysis of a E. coli galE mutant via the process of uridine 5′-diphosphate galactose accumulation, dGal-induced growth inhibition was characterized by cell burst without swelling and elongation of the original rod shaped cells. 2-Deoxy-D-galactose 1-phosphate (dGal1P) was the most probable effector for a bacteriocidal effect of dGal owing to the relationship between dGal-sensitive phenotype and plasmid-dependent galK gene expression. The synthesis of cell wall polysaccharides was functional in dGal-grown cells with the added D-glucosamine and N-acetyl-D-glucosamine, which were protective against dGal-induced growth inhibition. The present study proposes inhibition of fructose 1, 6- bisphosphatase related to de novo synthesis of amino sugar with accumulation of dGal1P as a cause of overall growth inhibition by dGal.