Bactericidal activity of the tail of Pseudomonas aeruginosa bacteriophage PS17

The tail of bacteriophage PS17 of Pseudomonas aeruginosa was shown to be bactericidal, and its properties were compared with those of pyocin R1. Temperature-sensitive mutants were isolated from PS17, and the products at nonpermissive temperature were morphologically characterized. Bactericidal substances were found in the lysates of such mutants that were defective in the head formation but not in the tail formation. Phage tails were purified from the lysate of one such mutant, and its chemical and biological properties were studied. Isolated tails killed sensitive cells by a single-hit process and repressed the uptake of leucine in sensitive cells. These results were consistent with the previous findings on the serological and morphological relationship between PS17 and pyocin R1. However, certain differences were also shown between them in shape and protein composition.