Mitomycin C and temperature induction of colicin B in the absence of deoxyribonucleic acid synthesis.

An Escherichia coli K-12 strain and its mutant, temperature-sensitive in deoxyribonucleic acid (DNA) synthesis, were used as hosts for two different ColB factors (ColB3-K166 and ColB4-K98). Induction of either colicin occurred in both hosts in the presence of mitomycin C at 42 C. Induction of the temperature-sensitive colicinogenic hosts also occurred without mitomycin C at 42 C at which temperature no DNA synthesis was observed. Colicin synthesis was a nonlethal event in ColB4-K98(+) cultures, whereas in cultures of ColB3-K166(+) induction led to death of a large fraction of the population.