Screening of the Marine Red Yeast Strains Producing Carotenoids and Optimization of the Process Conditions

In order to obtain the marine red yeast strains with high yield of carotenoids, 228 strains of marine red yeast were obtained from various marine environmental samples in the sea areas of Fujian Province. Through the screening and identification of the carotenoid-producing marine red yeast, the target strain Y37 was obtained, and the fermentation medium conditions were further optimized by single factor test and verified by shake flask. The results showed that: the strain Y37 was identified as the subspecies of Rhodotorula mucilaginosa. The best carbon source for the fermentation and production of carotenoid was mannitol, the best nitrogen source was fish meal, and the best salt concentration in the culture medium was 3%. Under the optimal fermentation conditions, the yield of carotenoid reached 128 ug·L⁻¹ in the shake-flask fermentation of strain Y37. Therefore, the microbial strains repository of marine yeast with the high-yielding carotenoid potential was isolated and obtained from various marine habitats in this study, which provided a new way for the large-scale preparation of carotenoids.