[Genetic variability of synthesis feature of carotenoids in Streptomyces globisporus 1912].

Seventeen spontaneous and induced mutants, that acquired a new characteristic--the synthesis of beta-carotene and lycopene, were obtained from strain Streptomyces globisporus 1912. It was found that spontaneous mutants inherited more stably the acquired carotenogenesis as compared to induced ones. Synthesis of carotenoids by all isolated Crt+ Lcp+ cultures is a constitutive feature. It was shown that Crt(+)-mutants (4Crt, 6Crt, 7Crt, RVCrt and R3Crt) synthesized beta-carotene and lycopene, while Lcp(+)-mutants (TpS16-1, TpS16-2, 4Lcp and R3Lcp)--only lycopene. The obtained mutants and transformants of S. globisporus 1912, synthesizing carotene were characterized by a simultaneous change of two or three phenotypic characteristics: synthesis of the antibiotic landomycin E. sporullation and carotenogenesis. It can be assumed that the high instability of this characteristic (carotenogenesis) in strain S. globisporus 1912 was caused by localization of the crt-genes cluster close to a TIR-element in a chromosome terminal region, frequent structural reorganization of DNA here were reported in the literature.