交替假单胞菌产几丁质酶的响应面优化

Optimization of fermentation conditions for chitinase production by the Pseudoalteromonas sp. DL-6 using the response surface methodology

采用响应面法对交替假单胞菌发酵产几丁质酶的培养基进行了优化。首先利用Plackett Burman实验设计筛选出影响产酶的3个主要因素,即胶体几丁质、发酵温度和pH。在此基础上用最陡爬坡路径逼近最大响应区域,再利用Box-Behnken实验设计及响应面分析法确定最佳条件。结果表明,胶体几丁质8.95g/L,蛋白胨2g/L,转速130r/min,接种量2%,发酵温度20℃,pH6.18,发酵时间96h,几丁质酶最大理论酶活为57.95U/mL。经3次实验验证,实际平均酶活与预测酶活相近,比优化前几丁质酶酶活提高了23.77%。

Response surface methodology was used to optimize the fermentation conditions of chitinase by Pseudoalteromonas sp.DL-6. Firstly,the important factors influencing chitinase production were identified by the method of Plackett-Burman as colloidal chitin,fermentation temperature,and pH. The path of steepest ascent was applied to approach the optimal region of the three significant factors. Box-Behnken design and response surface analysis were used to further investigate the optimal central levels and relationships of these factors. By using the quadratic regression model equation and analyzing the response surface of chitinase production,the optimal fermentation conditions were determined as followed ：colloidal chitin 8.95g/L,peptone 2g/L,shaking speed 130r/min, inoculums dose 2%, fermentation temperature 20℃, and pH 6.18, respectively. Under these conditons,the maximumtheoretic activity of chitinase was 57.95U/mL. After three verifications,the maximum theoretic value was consistent with mean value of verification test and the chitinase production was increased by 23.77% comparing to that before optimization.