[Isolation and study of the properties of Streptomyces kanamyceticus mutants with disorders of kanamycin biosynthesis].

The strains of Streptomyces kanamyceticus 1375 and 1 were exposed to N-nitroso-N-methyl urea, ethidium bromide and acriflavine and mutants with impaired biosynthesis of kanamycin (Kan-) were isolated. The majority of the mutants were genetically unstable and segregated with the formation of both the Kan- and Kan+ clones. The stable Kan- mutants were tested in pairs for the cosynthesis.

[Isolation and characterization of genetic recombinants in protoplast fusion in Saccharopolyspora erythraea].

Formation of genetic recombinants after conjugation and protoplast fusion in Saccharopolyspora erythraea, an organism producing erythromycin, was studied comparatively. After the protoplast fusion the frequency of all the classes of the haploid recombinants increased 10 to 460 times by comparison with the conjugation. The protoplast fusion was characterized by higher diversity of the recombinant classes, up to 45.