木聚糖酶高产菌株Pichia pastoris G12摇瓶发酵工艺的优化

Optimization of flask liquid fermentation process of high yield thermostable acid xylanase strain Pichia pastoris G12

目的研究甲醇诱导的Pichia pastoris G12在摇瓶发酵条件下产木聚糖酶的表达规律。方法以木聚糖酶酶活力为评价指标,通过单因素试验和L9(34)正交试验考察确定摇瓶发酵条件下pH、接种时间、甲醇体积分数、诱导时间等因素对酶活力的影响。结果各因素影响程度依次为pH>甲醇体积分数>诱导时间>接种时间,最优表达条件为接种时间21 h,pH为5.5,甲醇诱导体积分数为1.50%,诱导时间为162 h。在此最优条件下培养菌株酶活力可达395.124 U.mL-1。结论该研究为木聚糖酶的工业化生产和应用提供了依据。

Objective To observe the best fermention conditions for xylanase production of Pichia pastoris G12 by using methanol as the inducer. Methods With the xylanase activity as the evaluation index,the effects of culture conditions such as pH,inoculation time,methanol concentration and induction time on the enzyme activity of the recombinant xylanase of Pichia pastoris G12 were investigated by using single factor experiment and L9（34） orthogonal experiment. Results The influence degree of each factor was pHmethanol concentrationinduction timeinoculation time.The optimum combination was as follows：inoculation time of 21 hours,pH 5.5,methanol concentration of 1.50%,induction time of 162 hours.Under these conditions,the xylanase activity of recombinant xylanase reached 395.124 U·mL-1. Conclusion This study was meaningful for the production and application of xylanase in industry.