Near-UV Effects on the Induction of Prophage

Effects of near-uv (320-400 nm) on the induction of prophage have been studied for Escherichia coli K12λ, strains 15 and B. Gamma rays, 254-nm uv, and hydrostatic pressure were used as inducing agents. Prophage induction was assayed by observation of plaque-forming units in K12λ and detection of leakage, as evidenced by release of β-galactosidase from the cells. The results indicate that near-uv effects on lysogenic cells depend on the nature of the inducer. Some evidence that the action of near-uv can be related to modification of the envelope of the cell is presented.