Inhibition of Peptidoglycan Hydrolase Activity in Vivo and in Vitro by Energy Uncouplers in Escherichia coli

Abstract

ABSTRACT

The effects of energy uncouplers on in vivo and in vitro peptidoglycan hydrolase activities in Escherichia coli were determined. Sodium azide, potassium cyanide, and carbonyl cyanide m-chlorophenylhydrazone all inhibited ampicillin-induced lysis of exponential phase cultures, even when they were added to lysis-committed cultures. These energy uncouplers also inhibited the solubilization of radiolabeled peptidoglycan by bacterial suspensions that had been treated with 5% trichloroacetic acid by the method of Hartmann et al.³ to activate the peptidoglycan hydrolases. Therefore, the in vivo and in vitro activities of peptidoglycan hydrolases in E. coli are dependent on membrane energization.