[Multiple protective effect of an exometabolite (exometabolites) released by Escherichia coli during treatment with tetracycline].

Exponentially growing tetracycline-treated Escherichia coli cells release (an) as yet unidentified compound(s) into the medium. These compounds produce a protective effect on E. coli cells under conditions of heat, oxidative, and osmotic shocks, or in the presence of tetracycline. The protective effect is manifested as an acceleration of growth in the presence of tetracycline or under conditions of heat shock or as a shortening of the period of adaptation to other stresses.