以浒苔为碳源的地衣芽孢杆菌发酵产蛋白酶条件优化

Optimization of Fermentation Conditions for Protease Production by Bacillus licheniformis with Enteromorpha prolifera as Carbon Source

为了优化地衣芽孢杆菌(Bacillus licheniformis)以浒苔(Enteromorpha prolifera)为碳源进行发酵产蛋白酶的能力,以蛋白酶比活力为指标,通过单因素试验探讨不同因素对产酶效率的影响,在此基础上运用PlackettBurman设计筛选出了3个显著因素:培养基初始p H值、浒苔添加量和Na H2PO4添加量。采用响应面法对这3个显著因素进行优化,得到最佳产酶条件为培养基初始p H 6.66、浒苔添加量4.65%、Na H2PO4添加量0.027 4%,此条件下蛋白酶比活力预测值为66 354.70 U/g pro,3次实验验证值为66 966.37 U/g pro。验证值与基础发酵条件下的最大蛋白酶比活力18 206.16 U/g pro相比,提高了2.68倍。

This work reports on the selection and optimization of culture conditions and medium components as well as their levels for improved production of protease by Bacillus licheniformis with Enteromorpha prolifera as a carbon source by the combined use of single factor method, Plackett-Burman design and response surface methodology（RSM）. Initial medium p H, Enteromorpha prolifera concentration and Na H2PO4 concentration were identified as the most significant factors that influence protease production. The levels of the three factors were optimized using RSM to be 6.66, 4.65% and 0.027 4%, respectively. Under the optimized conditions, the predicted values of protease activity was 66 354.70 U/g protein and an average value of 66 966.37 U/g protein was obtained from three replicate experiments, which was 3.68 times higher than that before optimization.