富硒酵母培养条件的优化

对1株经过DES(硫酸二乙酯)、紫外线和氯化锂复合诱变后的产朊假丝酵母进行富硒发酵条件的研究,通过单因素及正交试验,确定葡萄糖为培养基的最佳碳源,添加4%～5%时可得到最高生物量与硒含量;蛋白胨和尿素的复合氮源为最佳氮源.分别添加蛋白胨0.5%,尿素0.9%,辅助氮源酵母膏0.4%,硒 25 μg /mL,摇瓶(250 mL)装液量30 mL,转速200 r/min,培养温度 28 ℃,pH 5～6,培养时间40 h,此条件下酵母生物量达到7.942 g/L,总硒含量达到16 486.48 μg /L.

Condition optimization in cultivation of selenium-enriched yeast

The study was made of fermentation conditions of selenium-enriched yeast. The following results were obtained by Single factor and orthogonal tests: the glucose was the optimal carbon source for yeast growth, and the optimal concentration of glucose was 4%～5%. The compound nitrogen which contained urea and peptone was the optimal nitrogen source for fermentation,and the optimal concentration of compound nitrogen were peptone 0.5% and urea 0.9%.The optimal concentration of yeast extract was 0.4%,and the optimal concentration of selenium was 25 μg/mL;the liquid volume of 30 mL in 250 mL flask at the speed of 200 r/min was the optimal condition for fermentation. The optimal initial pH for the strain growth was about 5～6. The optimal cultivation temperature was 28 ℃,and the fermentation could be finished in forty hours. Under the optimized conditions,the biomass (dry weight) reached 7.942 g/L and the total Se content of the cells was 16 486.48 μg /L.