基于响应面法的粘质沙雷氏菌BRC-CXG2发酵培养基优化

为了将粘质沙雷氏菌（Serratia marcescens）应用在松墨天牛（Monochamus alternatus）防治上，对粘质沙雷氏菌的培养基配方进行了优化。通过单因素试验筛选粘质沙雷氏菌发酵培养基的碳源、氮源和无机盐，利用Plackett-Burman试验设计确定3个主要影响因素，通过最陡爬坡试验，结合Box-Behnken Design试验设计及响应面分析法优化培养基组成成分，获得培养基最佳配方与发酵条件：葡萄糖23.27 g·L^-1、蚕蛹粉22.37 g·L^-1、酵母粉10 g·L^-1、硫酸镁2 g·L^-1、磷酸氢二钠3 g·L^-1，氯化钠2 g·L^-1；在28 ℃、150 r·min^-1条件下发酵36 h，装液量体积分数为50 mL/250 mL，接种量4.73 %，pH 7.1~7.3。最后，根据最优培养条件验证发现优化后培养基中生长的菌落数为6.0×10⁹ cfu·mL^-1，是初始培养基的9.42倍，与模型预测值相符。研究结果为粘质沙雷氏菌的发酵生产提供了理论基础，为松材线虫病（pine wilt disease）的防治提供了新的途径。

Optimization of Serratia marcescens BRC-CXG2 Fermentation Medium Based on Response Surface Methodology

In order to develop the application of Serratia marcescens in the control of Monochamus alternatus， the medium formulation of Serratia marcescens was optimized in this study. The carbon source， nitrogen source and inorganic salt of S. marcescens fermentation medium were screened by single factor test， and 3 main influencing factors were determine by Plackett-burman design. The composition of the medium was optimized by the steepest climbing test combined with Box-Behnken Design and response surface analysis， and the optimal medium formula and fermentation conditions were obtained： glucose 23.27 g·L^-1， soybean cake meal 22.37 g·L^-1， yeast extract 10 g·L^-1， MgSO₄ 2 g·L^-1， Na₂HPO₄ 3 g·L^-1， NaCl 2 g·L^-1. At 28 ℃， 150 r·min^-1 for 36 h， the volume fraction of liquid was 50 mL/250 mL， the inoculation amount was 4.73 %， pH 7.1~7.3. Finally， according to the optimal culture conditions， the number of bacteria growing in the optimized medium was 6.0×10⁹ cfu·mL^-1， 9.42 times of the initial medium， which was consistent with the predicted value of the model. These results provided theoretical basis for the fermentation production of S. marcescens and provide a new approach for the control of pine wilt disease.