[Manifestation of polylysogeny in Pseudomonas vignae]

Ultraviolet irradiation and treatment with mitomycin C demonstrated that a culture of Ps. vignae, strain 1025, was polylysogenic, as electron microscopic preparations of phagolysates revealed two types of virus particles: "large" with a hexagonal head of 700 A in diameter, and "small" with a round head of 500 A in diameter. Subcultivation of the test and indicator cultures showed in both cases formation of particles of these phages, the content of "small" virions increasing with the number of passages of negative colonies. Attempts to separate these viruses biological methods were not successfull. The phenomenon of polylysogeny is unusual in that moderate phage adsorbed repeatedly on host bacteria culture and lysed it. The causes of the discovered phenomenon are discussed.