Envelope alteration of Escherichia coli HB101 carrying pEAP31 caused by Kil peptide and its involvement in the extracellular release of periplasmic penicillinase from an alkaliphilic Bacillus

Abstract

The plasmid pEAP31 contains the colicin E1 kil gene. Peptidoglycan and outer-membrane components (lipopoly-saccharide, proteins and phosphatidylethanolamine) decreased concurrently in the envelope fraction from Escherichia coli HB101 carrying pEAP31 during the stationary phase of growth. At almost the same time. D-alanine residues in peptidoglycan decreased. The Kil peptide is suggested to affect, directly or indirectly, the turnover of peptidoglycan in stationary phase and, as a result, to cause partial exfoliation of the outer membrane. Periplasmic proteins are liberated from E. coli HB101 (pEAP31) probably because of the exfoliation of outer membrane.