Starvation as an inducer of error-free DNA repair in Escherichia coli.

Previous work in this laboratory has shown that heat shock or vitamin B1 deprivation induces an error-free DNA-repair process in Escherichia coli. The system is absolutely dependent on excision repair, while its induction is delayed in lon- or recA- cells. We have now shown that starvation of E. coli for amino acids, glucose or phosphate, conditions known to induce the stringent response or the glu and pho regulons, respectively, leads to a similar uvrA-dependent increase in UV resistance and decrease in UV-induced mutation frequency. These results support the hypothesis that the effect is a general response to non-mutagenic stress that may play an important role in the survival of cells exposed to harsh environments.