高产乙醇酿酒酵母的筛选鉴定及发酵条件优化

摘要

从酵母浸粉中分离筛选出一株高产乙醇的菌株 DL5168，经形态学观察、生理生化学及分子生物学鉴定，确定该菌株为酵母属的酿酒酵母（Saccharomyces cerevisiae）。通过优化实验，确定菌株 DL5168发酵的最适条件为：初始葡萄糖浓度180 g/L；发酵温度30℃。在此条件下，菌株发酵的最终乙醇浓度为113.9 g/L，比对照菌株的乙醇浓度提高36%；乙醇转化率为0.64 g/g，比对照提高39%。%　　Yeast DL5168 of high-yield ethanol-producing strain was isolated and screened from yeast extract. The strain DL5168 was identified as Saccharomyces cerevisiae by morphology, physio-biochemistry and molecular biology methods. The optimum fermentation conditions for ethanol were 180 g/L of initial glucose concentration and 30 oC culture temperatures. The final ethanol concentration and yield in flask fermentation under the optimum conditions were 113.9 g/L and 0.64 g/g, respectively, increasing 36% and 39% compared with the control strain GGMCC No. 2.604.