高生物量富硒产朊假丝酵母培养基优化

对富硒产朊假丝酵母发酵培养基进行优化，获得高生物量富硒酵母。从6种发酵培养基中确定G改良培养基为最佳培养基。利用Plackett-Burman设计法从影响富硒产朊假丝酵母生长的12个因子中筛选出葡萄糖、蛋白胨、KH2PO4、CuSO4添加量这4个关键因子。再利用Box-Behnken试验设计及响应面分析法确定关键因子的最佳水平及交互作用。试验得出各关键因子的最优组合为葡萄糖30 g/L、蛋白胨17 g/L、KH2PO4 6.5 g/L、CuSO4 0.01 g/L。结果表明，培养基优化后酵母生物量为12.01 g/L，有机硒含量为1 337.46 μg/g，谷胱甘肽为134.27 mg/L。将培养基中亚硒酸钠添加量由25 μg/mL提高至30 μg/mL，酵母生物量为11.21 g/L，有机硒为1 673.32 μg/g，谷胱甘肽为126.80 mg/L。

Optimization of culture medium for high-biomass and selenium-enriched Candida utilis

Nature fermentative medium for high-biomass and selenium-enriched Candida utilis culture was investigated. G-improvement medium was chosen as the optimal from six fermentation mediums. The Plackett-Burman design results indicated that glucose, peptone, KH2PO4, CuSO4 were the key factors of 12 nutrient factors for the growth of C. utilis. The optimal levels of the key factors and their interactions were determined by Box- Behnken experiments design and response surface analysis. Results showed that the optimal medium formula were glucose 30 g/L, peptone 17 g/L, KH2PO4 6.5 g/L and CuSO4 0.01 g/L. Under the optimal conditions, the biomass of selenium-enriched C.utilis was 12.01 g/L, the organic selenium content was 1 337.46 μg/g, and the glutathione was 134.27 mg/L. Using the optimal medium supplemented with sodium selenite (Na2SeO3) 30 μg/ml instead of 25 μg/ml, the yeast biomass, organic selenium and glutathione were 11.21 g/L, 1 673.32 μg/g and 126.80 mg/L, respectively.