Abstract:A yeast strain YS-185 isolated from the ocean can produce astaxanthin. 26S rDNA sequence analysis showed that the strain belongs to Rhodotorula glutinis. The effects of culture medium components and fermentation conditions on the marine yeast growth and pigment yield were investigated in shake flasks. The results showed that the optimum culture medium for the bacteria growth consisted of glucose (8g/L), peptone (8g/L), and the optimum fermentation conditions were initial pH 5.5, shaking speed 200r/min, inoculum level 8%(v/v), and temperature 20℃. The optimum culture medium for astaxanthin production consisted of glucose (8g/L), peptone (8g/L), and the optimum fermentation conditions were initial pH 5.5, shaking speed 220 r/min, inoculum level 8%(v/v) and temperature 25℃. We found that temperature had significant influence on the bacteria growth and the astaxanthin production based on the data analysis of the orthogonal experiments. An overall 69.7% increase of astaxanthin yield (2.670μg/ml) was obtained compared with that of the original conditions (1.572μg/ml). Marine yeast YS-185 had the potential to produce astaxanthin at a large scale.
