[New phages of a polylysogenic culture of Actinomyces griseus]

The culture of Actinomyces griseus 15 was found to have a more complicated phage composition than it was supposed earlier. A new virulent mutant B has been isolated, which differs by its properties from the phage of Act. griseus 15, type I, isolated earlier. Phage lysates of the virulent mutants originating from different temperate phages of Act. griseus 15. Therefore, the culture of Act. griseus 15 is polylysogenic, defective lysogenic and contains at least three different phages.