高产谷胱甘肽酵母菌株的选育和培养条件的初探

以Saccharomyces cerevisiaeG796-2为出发菌株,通过紫外线照射结合乙硫氨酸平板筛选,连续两代诱变筛选分离得到高产突变株Saccharomyces cerevisiae SE-2;摇瓶试验胞内谷胱甘肽含量达到2.2%,较出发菌株G796-2提高62.9%,传代试验表明其遗传性能稳定。对SE-2的培养条件进行了研究。采用正交化实验和双碳源实验对培养基进行优化,结果表明,最佳初糖浓度6%,葡萄糖/糖蜜=3.5:1,半胱氨酸的添加浓度5mmoL?L?1较为适宜。在优化的培养条件下培养39h,SE-2谷胱甘肽总量达180mg?L?1以上,较G796-2提高81.2%。

Screening of Saccharomyces cerevisiae for Glutathione Over-production and Study of Culture Conditions

Saccharomyces cerevisiae is an important strain of glutathione production in fermentation. The screening of high glutathione-producing mutant and optimizing its culture conditions were studied. A strain of Saccharomyces cerevisiae G796-2 was isolated from 8 yeast strains for its higher intracellular glutathione content, and then the strain was mutagenized by ultraviolet and ethionine. A new mutant Saccharomyces cerevisiae SE-2 was isolated after two generation mutation whose intracellular glutathione content reached 2.2%, it is 62.9% higher than its parent in flask experiment. Results show that its high glutathione-producing ability can be inherited after several generation cultures. The orthogonal method results of the mutant culture conditions and the experimental results of two carbon sources test are as following: the optimal glucose concentration is 6%, the optimal rate of glucose/molasses is 3.5:1 and the optimal cysteine concentration is 5mmol?L?1. The glutathione yield of SE-2 was 180mg?L?1after cultivating 39 hours under the optimum conditions , it was 81.2% higher than that of G796-2.