Screening and characterization of red yeast Xanthophyllomyces dendrorhous mutants

Three different strains of carotenoid accumulating Xanthophyllomyces dendrorhous mutants, JH1, JH2, and JH3, were isolated by NTG (N-methyl-N′-nitro-N-nitrosoguanidine) mutagenesis, which might potentially be useful for animal feed as well as for studies on the regulation and biosynthesis of astaxanthin. Mutants were selected based on the capability of growth and carotenoid production on the YM agar plate containing chemical inhibitor, β-ionone. Astaxanthin-overproducing mutant JH1 produced 4.032 mg astaxanthin/g dry cell weight, and this value was about 15-folds higher than that of wild-type. β-Carotene-overproducing mutant JH2 produced 0.273 mg β-carotene/g dry cell weight, and this was 4-folds increase from that of wild-type. In contrast, JH3 was a white-colored mutant that was unable to produce carotenoid pigment.