Effect of Infection with Phage Lambda on the Synthesis of Protein, RNA and DNA in Escherichia coli

Summary: Delay in deoxyribonucleic acid (DNA) synthesis after use of ultraviolet radiation to induce Escherichia coli lysogenic for phage λ was due to the irradiation procedure; the same delay was found in non-lysogenic bacteria exposed to the same dose of radiation. After infection with phage λ c or λ V in 0.02 m-MgSO4, DNA synthesis began without delay when complete medium was added. During vegetative development of phage in induced bacteria, 81--89% of the DNA synthesized was accounted for in the phage progeny, indicating that host DNA synthesis is much diminished and may be completely inhibited. Mature phage particles arose soon after the appearance of serum blocking power (SBP) and endolysin activity. Induced bacteria synthesized up to 15 times more SBP than was incorporated into complete phage particles: the excess SBP was not sedimented at 40,000 g (unlike phage particles), but about half was sedimented at 90,000 g, the rest remaining in the supernatant fluid. Whilst protein and RNA synthesis in infected or induced bacteria was initially similar to that in the control, there was a marked decrease of synthesis in the second half of the latent period.