Abstract: The effects of biotin on cell growth and astaxanthin accumulation of Phaffia rhodozyma were investigated in flasks. The addition of biotin promoted cell growth but decreased the cell astaxanthin content. The highest specific growth rate of 0.110 h-1 was achieved at 10 μg/L biotin. The highest cell dry weight of 9. 95 g/L was achieved at 6 μg/L biotin, which increased by 32% compared with 7.53 g/L when there was no biotin. As for astaxanthin production, the highest yield of astaxanthin of 3 825 μg/L and productivity of 53 μg/(L · h) were reached at 2 μg/L biotin, which increased by 30% compared with 2 944 μg/L and 41 μg/(L · h) with the absence of biotin, while the highest astaxantnin content of 391μg/g was reached at 0 μg/L biotin. This method provides a simple and inexpensive means to increase astaxanthin production in industrial fermentations.

Key words: biotin, astaxanthin, Phaffia rhodozyma