Penicillin-induced lysis of Escherichia coli in medium that does not support sustained growth.

Exponentially growing cells of an Escherichia coli auxotroph that are washed and resuspended in buffer containing a carbon source undergo sufficient growth to render them susceptible to penicillin-induced lysis, even in the absence of the required metabolite. This lysis is probably responsible for the reduction in intracellular enzyme activity previously attributed to a direct effect of penicillin upon the enzyme.