Inhibition of beta-galactosidase synthesis in Escherichia coli after infection with different DNA and RNA phages.

Infection of Escherichia cooi with T1, T2r+, T3 and T4 phages leads to an immediate inhibition of beta-galactosidase synthesis. Similar results were obtained with the virulent mutant of phage lambda. The degree of inhibition of beta-galactosidase synthesis depends on the time delay between the addition of the inducer and the phage particles, and on the amount of phage DNA, which has penetrated into the host cell. RNA phage MS2 exhibited no inhibitory effect on enzyme synthesis.