Abstract
Two types of pyocins were found in Pseudomonas aeruginosa and named pyocin type S and type R. Production of both types of pyocin was inducible by ultraviolet ray or by mitomycin. An S-type pyocin was prepared from strain P28 and its nature was investigated. The pyocin activity was labile to heat or proteinase treatment. Its molecular weight was estimated to be around 1×105. The same type of pyocin was found in M11, a fertile strain originally isolated by Holloway.
Pyocin type R, which has a structure very similar to some phage tails, was found among three strains of Japanese and Australian origin and named pyocin R2, R3, and R4. These pyocins distinguished by the difference in their action spectrum but were otherwise indiscernible. They behaved in the same manner during the purification process including DEAE-cellulose chromatography. Moreover an immunological cross reaction was observed among these R-type pyocins. Anti-pyocin R or R2 serum also neutralized other R-type pyocins. Electron microscopy revealed a similar dimension for each pyocin particle; 15Å×1, 300Å.
