Biochemical modifications in lysogenic B. megatherium 899 (1) after induction with ultraviolet light

Abstract

1. 1. The time elapsed between induction of B. megatherium 899 (1) by irradiation with ultraviolet light, and formation of the first intra- and extra-cellular bacteriophages has been measured at 27 and 37°C. The latent period is prolonged by an increase in the inducing dose of ultraviolet light. 2. 2. A study of the biochemical modifications occuring after induction of lysogenic B. megatherium has shown that, concomitant with the residual growth, respiration increases, and ribonucleic acid is synthesized. The synthesis of desoxyribonucleic acid is blocked during approximately the first third of the latent period. Rapid synthesis then commences and continues until the moment of lysis. 3. 3. The biochemical modifications during development of temperate phages in induced lysogenic bacteria have been compared with those found in bacteria infected with virulent phages, which block growth completely. Whereas growth, ribonucleic acid and enzyme synthesis does, or does not, occur, depending on the phage-host system studied, the pattern of desoxyribonucleic synthesis seems to be a common property of all phage-host systems examined heretofore.