[Genetic control of the protective effect of spermidine in Escherichia coli cells as affected by mitomycin C].

The lethal action of mitomycin C and the effect of mutual treatment with mitomycin C and spermidine on Escherichia coli were studied. DNA repair in cells treated with mitomycin C was shown to have some differences, as compared to that of UV-induced pyrimidine dimers. The presence of the additive sbcB mutation increases the resistance of wild-type bacteria as well as of recBrecC and recF mutants to the lethal action of mytomicin C. Preliminary treatment of bacteria with spermidine increases resistance to the lethal action of the mutagen in wild-type bacteria as well as uvrB, recBrecC and sbcB strains. However, no such effect was observed in recF, recFsbcB and uvrE strains. The data suggest that the protective action of spermidine may be connected with stimulation of RecF-pathway of postreplication repair.