响应面法优化芽孢杆菌CJPE209产角蛋白酶发酵培养基的研究

采用响应面法对芽孢杆菌（Bacillus sp.）CJPE209产角蛋白酶的发酵培养基组分进行优化。在前期单因素优化的基础上利用Plackett-Burman试验设计筛选出影响产酶的2个显著性因素：羽毛粉、蔗糖。在此基础上，采用最陡爬坡试验确定中心复合试验的中心点，然后对其他不显著因素进行最低添加量试验以降低生产成本和简化培养基组分。利用中心复合试验，得到预测最佳培养基组成为羽毛粉5.6 g/L、蔗糖13.6 g/L、尿素5.0 g/L、KH2PO4 0.4 g/L、MgSO4 1.44 g/L、CaCl2 1.1 g/L、NaCl 5.0 g/L，预测角蛋白酶酶活为501.9 U/mL。用预测最佳培养基来进行发酵验证试验，结果实际角蛋白酶酶活为503.5 U/mL，表明模型能较好的预测发酵后酶活。

Optimization of fermentation medium for keratinase production from Bacillus sp. CJPE209 using response surface methodology

The formula of fermentation medium for keratinase production by Bacillus sp. CJPE209 was optimized by response surface methodology. Based on single factor experiments, two significant factors (feather meal, sucrose) that affected enzyme activity were screened by Plackett-Burman experiments. On that basis, the steepest ascent experiment was used to determine the center point of central composite design (CCD), and the minimum addition experiments were applied to confirm the minimum addition of other non-significant factors for reducing the cost and simplifying the medium components. Then the optimal medium formula was forecasted by CCD as follows: feather meal 5.6 g/L, sucrose 13.6 g/L, urea 5.0 g/L, KH2PO4 0.4 g/L, MgSO4 1.44 g/L, CaCl2 1.1 g/L, NaCl 5.0 g/L, and the forecasted keratinase activity was 501.9 U/ml. The actual keratinase activity in verification tests reached 503.5 U/ml, which showed that the model could be used to predict keratinase activity after fermentation.