Abstract: In order to improve the yield of carotenoid in the fermentation of Rhodotorula Y-5, mineral salts in the fermentation medium were optimized. KH₂PO₄, MgSO₄ and NaCl were found to be the important factors affecting carotenoid production significantly by the analysis of Plackett-Burman design. The optimization results based on Box-Behnken design and response surface methodology showed that the production of carotenoid could reach 14.51 mg/L, when KH₂PO₄ was added at 0.58 g/L, MgSO₄ at 0.49 g/L, and NaCl at 0.28 g/L. Compared with the control medium without added mineral salts, the production of carotenoid was increased by 25.09%.

Key words: Rhodotorula Y-5, carotenoid, mineral salt, Plackett-Burman design, response surface methodology