Presence of inducible DNA repair in Bacillus thuringiensis

Weigle reactivation of ultraviolet-irradiated luminal diameter 8 bacteriophage was observed after ultraviolet treatment of Bacillus thuringiensis cells. A slight increased frequency of clear plaque mutants was detected among the survivors. The kinetics of induction of the phage reactivation and phage mutagenesis have been determined. The presence of chloramphenicol before and after irradiation abolished the induction of repair and mutagenesis. These experiments suggest that, in spite of the relatively small mutagenic response in bacteriophage progeny, B. thuringiensis has an inducible repair system responsible to the significant Weigle reactivation of irradiated phage.