重组毕赤酵母生产耐高温α-淀粉酶发酵条件的优化

摘要

The methanol-induced expression of thermostableα-amylase in a recombinant Pichia pastoris strain with the thermostableα-amylase gene of Bacillus licheniformis that had been constructed in our previous work was investigated during shake flask cultivation.A 4-variable linear regression design was used to explore the effects of 4 main cultivation conditions such as induction time,methanol amount,pH and inoculation amount on the expressed activity of thermostableα-amylase.A regression model describing the relationship between them was established.It was found that the optimal fermentation conditions were 96 h cultivation at an inoculation amount of 150 mL/100mL and a shake speed of 200 r/min in the presence of 0.5% methanol,resulting in a thermostableα-amylase activity of 217.2 U/mL.%利用重组毕赤酵母诱导表达可产生耐高温α-淀粉酶,在摇瓶发酵基础上,从诱导时间、甲醇添加量、pH值、接种量4个因素考察发酵条件对耐高温α-淀粉酶酶活力的影响,结合四元线性回归正交试验设计研究方法构建出甲醇诱导重组毕赤酵母生产耐高温α-淀粉酶的回归模型;优化最佳工艺参数为：诱导时间96h、甲醇添加量0.5%、接种量150mL/100mL、摇床转速200r/min。确定最优工艺条件下,耐高温α-淀粉酶酶活为217.2U/mL。