Effects of antimutagens on prophage induction in E coli lysogenic for lambda

The effects of caffeine, acriflavine, spermine, quinacrine, and adenosine on spontaneous and UV-induced prophage induction in repair-proficient and -deficient strains of lysogenic Escherichia coli were examined. Caffeine caused a coinducing effect on UV induction in KMBL 160 (repair proficient) and KMBL 163 (uvrA), an anti-inducing effect in KMBL 161 (uvrE), and had no detectable effect in KMBL 164 (uvrC). Acriflavine increased UV induction in KMBL 160 and decreased it in all three repair-deficient mutant strains. Spontaneous induction was reduced by acriflavine in all four strains. Spermine caused a decrease in UV induction in KMBL 160 and KMBL 164, while it had limited effect in KMBL 161 and KMBL 163. For spontaneous induction spermine caused an increase in KMBL 160 and KMBL 163, a decrease in KMBL 164 and no detectable effect in KMBL 161. Quinacrine had no significant effect on spontaneous induction in KMBL 160 and KMBL 164, but caused a decrease in spontaneous induction in KMBL 161 and KMBL 163. Quinacrine produced no effect on UV induction in KMBL 160; however, it decreased UV induction in the three repair-deficient strains to some extent. A significant increase in spontaneous induction in KMBL 160 was caused by adenosine, while it had little effect in the repair-deficient strains. UV induction was not affected by adenosine.