Spontaneous and induced variability of carotenoid biosynthesis characteristics in Streptomyces globisporus 1912
Holembiovs'ka, S.L.; Matseliukh, B.P.
Mikrobiolohichnyi Zhurnal 70(6): 18-23
2008
ISSN/ISBN: 0201-8462 PMID: 19351044 Document Number: 615156
Spontaneous and induced variability of carotenoid biosynthesis was studied in seven strains of Streptomyces globisporus 1912 with the model of direct and reverse mutations. The appearance of spontaneous pigmentless (Crt) colonies in mutants 4 Crt and 7 Crt was 0.9% at an average. Crt(-) mutants were not observed among 6596 examined colonies of the strain 6 Crt. The RVCrt strain has high level of carotenoid biosynthesis variability: the frequency of appearance of Crt(-)-mutants was 22.1%. Nitrosoguanidine increased frequency of Crt(-)-mutants in 7 Crt strain by one order approximately. This mutagen was not effective in 6 Crt strain: the pigmentless mutants were not observed among 4189 red colonies. The frequency of Crt(+) revertants in pigmentless strains 4W, 7W, 7Y was high too (10(-2)-10(-3)). High variability of the property of carotenoid production is explained by localization of cluster crt genes on one of the ends of linear chromosome side by side with TIR sequence, which is the cause of structural rearrangement of the chromosome. The potato medium is more favourable for manifestation and stabilization of the property of carotenoid production in comparison with soy-bean agar.