Prophage inactivation in recB-proficient Escherichia coli K12 (lambda) lysogens after ultraviolet irradiation

Summary If ultraviolet irradiated, -lysogenic Escherichia coli K12 bacteria are incubated for 4 to 6 h at 30° C, prophage becomes inactive in the non-surviving cells. This was demonstrated by the use of cIts857ind1 prophage which can be induced by heat but not by ultraviolet light. An analysis with various bacterial mutants showed that RecBC recombination enzyme is required in conjunction with RecA protein for prophage inactivation.