Mutant of Lambda Bacteriophage Producing a Thermolabile Endolysin.

Campbell, Allan (University of Rochester, Rochester, N.Y.) and Alice del Campillo-Campbell. Mutant of lambda bacteriophage producing a thermolabile endolysin. J. Bacteriol. 85:1202-1207. 1963.-Endolysin from lambda bacteriophage and a temperature-sensitive mutant thereof was partially purified. The mutant enzyme was distinguishable from the wild type by its greater rate of inactivation by high temperature and by urea. Lysogenic cells carrying the mutant phage did not lyse after induction if kept at 43 C, but, at times around 70 min after induction, rapid lysis occurred following transfer to lower temperatures. This lysis was not inhibited by cyanide or chloramphenicol and therefore probably resulted from enzyme already synthesized at the high temperature. Addition of these inhibitors to the culture at 43 C rapidly destroyed the ability to lyse after a subsequent temperature shift.