【作者】 何俊勇；

【导师】 裘娟萍；

【作者基本信息】 浙江工业大学 ， 生物化工， 2004， 硕士

【摘要】 以乙硫氨酸和氯化锌为筛选标记，对出发菌株SL21通过紫外线诱变处理，运用推理育种技术，选育到一株抗乙硫氨酸和氯化锌的突变株HY78，该突变株经摇瓶发酵谷胱甘肽的产量为76.0mg／L，干细胞谷胱甘肽的含量为10.0mg／g，分别比出发菌株SL21提高268.9％和263.0％。该菌株经10次传代培养，谷胱甘肽产量仅下降了13.0％，是一株性状较稳定的优良菌株。 运用单因素实验和正交实验设计对突变株HY78产谷胱甘肽的发酵条件进行了研究，研究表明该突变株产谷胱甘肽的最佳发酵条件为培养温度30℃、初始pH7.0、摇床转速180r／min、接种龄18h、接种量10％，摇瓶装液量30ml／250ml；最佳培养基组成是：糖蜜40g，牛肉膏20g，Cys·HCl 1.5g，MgSO₄·7H₂O 9g，KH₂PO₄ 1g，ZnSO₄5mg，水1000ml，结果表明突变株HY78在该优化条件下摇瓶发酵，发酵液中谷胱甘肽的含量可达182.6mg／L，较优化前提高了140.3％。 在摇瓶培养的基础上，通过分批培养和补料分批培养，在3.7L自动生物发酵罐中对突变株HY78生物合成谷胱甘肽进行了扩大培养，结果表明分批培养较摇瓶培养谷胱甘肽的产量下降了15.9％，仅有157.6mg／L，而在补料分批培养中，由于流加了培养液，谷胱甘浙江工必大学硕士格义肤的产量较分批培养提高了59.7%，为251.7mg/L。更多还原

【Abstract】 A Ethionine- and Zinc Chloride-resistant mutant HY78 was obtained from its parent strain SL21 by UV treatment and rational screening. The glutathione productivity of the mutant reached 76.0mg/L by flask culture, which was 268.9% higher than the parent strain. And the glutathione content in the dried cells reached 10.0mg/L, which was 263.0% higher than the parent strain. A descend of only 13.0% in the glutathione yield of the mutant was observed after ten times of subculture. Therefore, the obtained mutant is a stable strain.Studies were carried out on the fermentation condition through Single Factor design and Orthogonal Test design, which showed that the optimum fermentation condition was culture temperature 30 ℃, initial pH7.0, rotate speed 180r/min, inoculum age 18h, inoculum size 10%, medium volumes 30ml/250ml. And the optimum medium composition was molasses 40g, beef extract 20g, Cys HCl 1.5g, MgSO4 7H2O 9g, KH2PO4 1g , ZnSO4 5mg, water 1000ml. In this condition the glutathione content came to 182.6mg/L, which was 140.3% higher than that of non-optimized medium.In a 3.7L scale batch bioreactor, the rules of glutathione fermentation were studied by batch and fed-batch operation. The result showed that the glutathione content in the batch culture was only 157.mg/L, which was 15.9% lower than shake flask culture. While the glutathione content in the fed-batch culture reached251.7mg/L, which was 59.7% higher than batch culture.更多还原