Response of Bacillus thuringiensis to bacteriophage CP-51.

Bacteriophage CP-51, a transducing phage of Bacillus cereus was able to replicate on all eight varieties of Bacillus thuringiensis tested. Three general plaque types were observed on each strain although one type predominated on each strain. The plaque size was uniform for each strain regardless of plaque type. The bacterial strain used as source of the phage had no effect on plaque type or size found on any host strain. CP-51 was stable in infected spores of B. thuringiensis var. kurstaki for at least 305 days even though most of the spores had lost refractility. Free phage paricles produced in B. thuringiensis were stable for at least 10 days in broth at 14 degrees C but were very unstable at 4 degrees C.