[Synthesis of carotenoids by mutant strains of Streptomyces globisporus 1912].

Landomycin-deficient mutants (24) were obtained under the effect of nitrosoguanidine on the strains 3-1 and RSp2 of Streptomyces globisporus 1912, high active procedures of polyketide antibiotic landomycin E. Two strains of these mutants produced red and one strain--yellow pigments. The absorption spectra of the pigments purified by means of thin layer chromatography were characterized by three maxima of absorption of acetone 446-448, 472-474 and 501-507 nm resembling the same characteristic of lycopene. The Rf values of isolated pigments and lycopene do not differ between themselves. The corn medium is more optimal for lycopene synthesis by strains of S. globisporus 1912 in comparison with soy one. The highly active mutants synthesized 2 mg of lycopene per 1 g of dry biomass. High frequency of spontaneous mutability of lycopene production of isolated strains can be explained by the localization of gene cluster for carotenoid biosynthesis on the one end of linear chromosome, where genetic rearrangements often take place (amplifications, deletions, recombination) because of the presence of terminal inverter DNA repetitions.