响应面法优化S2菌株的培养条件

利用快速筛选方法从大庆采油三厂油田采出水中筛选出高产生物表面活性剂菌株S2，经鉴定为芽孢杆菌属.对S2菌株产生的生物表面活性剂进行提取及纯化后，通过离子鉴别实验及红外光谱法对其进行定性检测，确定其种类为非离子型脂肽类.以菌种S2产生的发酵液的乳化指数（E24）为指标，通过响应面优化方法对S2菌株的培养条件进行优化，以接种量、pH值、温度、摇床转速为因素优化对象进行实验.在此模型的基础上，通过二次回归方程得出最佳值是pH为7.2、温度为43.5 ℃ 、接种量为5.2%（V/V）、摇床转速为162 r/min.在优化后的最佳培养条件下，测得菌株S2所产生发酵液的最优E24为81.20%.
S2 strain that highly produces biosurfactant was screened from the oilfield water of three plants in Daqing Oilfield in the rapid screening method, and the S2 strain was identified as Bacillus sp.. Through FT-IR and ion identification test, S2 biosurfactant was identified as nonionic lipopeptide biosurfactant. This experiment treated emulsification index (E24) of S2 strain fermentation broth as the object. Through response surface optimization method, the culture conditions (inoculum, pH, temperature and rotation speed) of the S2 strain were optimized. On the basis of response surface model, the optimum pH value was 7.2 and the temperature was 43.5 ℃, inoculation of 5.2% (V/V), rotation speed was 162 r/min through the quadratic regression equation. Under the optimal condition, the best E24 of S2 strain fermentation broth was 81.20%.