Isolation of Streptomyces globisporus and Blakeslea trispora mutants with increased carotenoid content.

Hyperpigmented mutants of Streptomyces globisporus 1912-Hp7 and Blakeslea trispora 18(+), 184(-) were isolated by action of hydrogen peroxide and nitrosoguanidine, correspondingly, from initial strains S. globisporus 1912-4Lcp and B. trispora 72(-), 198(+).

[The action of hydrogen peroxide on mutants of Streptomyces globisporus 1912 with different carotene-synthesizing activity].

The paper deals with dependence of survival of Crt(+)- and Crt- mutants of Streptomyces globisporus 1912 in conditions of oxidizing stress caused by hydrogen peroxide on the level of lycopene and beta-carotene biosynthesis. Pink mutants 4Lcp, RVLcp and R3Lcp, which produce lycopene, are the most resistant to hydrogen peroxide. Red mutants 4Crt, 6Crt, 7Crt, 7Y RVCrt, R3Crt--producers of lycopene and beta-carotene have the average level of resistance to H2O2.

[Streptomyces globisporus 1912 mutants highly sensitive to ultraviolet radiation, their antibiotic activity and reparation ability].

Twenty five mutants defective in biosynthesis of antitumor antibiotic landomycin E and 22 mutants with higher level biosynthesis of this antibiotic were obtained after nitrosoguanidine mutagenic treatment of wild strain of Streptomyces globisporus 1912 spores. Six of them (5 mutants of LndE and 1 mutant of LndE+) were found to carry uvs-mutation responsible for high level UV-sensitivity. Uvs-mutants 1912-11 and 1912-16 were highly sensitive to the action of nitrous acid, hydrogen peroxide and methyl-methane-sulfonate.

[Resistance of the colored and non-pigmented mutants of Streptomyces globisporus 1912 to the action of UV-rays].

The lethal action of ultraviolet rays has been studied on colored 4Crt, 4Lcp, 6Crt, 7Crt and white 4W, 4W1, 7Y, 7W2, 7W6 mutants of S. globisporus 1912. It was shown, that all studied mutants are more resistant to action of ultraviolet light in comparison with initial strain 1912.

[Biosorption ability of mutants of Rhodotorula mucilaginosa UCM Y-1776].

Twenty stable mutants with various coloration intensity have been allocated in carotene-synthesizing natural strain Rhodotorula mucilaginosa UCM Y-1776 (wild type) after nitrosoguanidine action. Two brightly orange mutants 4L and 11 and one non-pigmented mutant 2 were chosen for the further researches. The ultraviolet was inefficient as a mutagen.