响应面法优化纳豆激酶发酵培养基

纳豆激酶具有良好的溶解血栓的功效，由于纳豆激酶目前的发酵水平不高，限制了其应用。该研究以纳豆激酶活力为响应值，在单因素试验基础上，采用Plackett-Burman 试验、最陡爬坡试验和响应面法对纳豆激酶培养基配方进行了优化。结果表明，通过Plackett-Burman试验筛选出豆粕粉、无水氯化钙、甘油为影响纳豆激酶活力的主要因素。最后运用响应面分析确定纳豆激酶最优发酵培养基为：甘油43 g/L、豆粕粉24 g/L、无水氯化钙0.14 g/L、七水硫酸镁0.80 g/L、十二水磷酸氢二钠3.00 g/L、无水磷酸二氢钾1.00 g/L、L-甲硫氨酸0.20 g/L，此条件下纳豆激酶活力最高为（4 281±103）FU/mL，是优化前的1.97倍。

Optimization of nattokinase fermentation medium by response surface methodology

Nattokinase has good thrombolytic efficacy, and its application was limited due to the low nattokinase fermentation level. Using nattokinase activity as the response value, the formulation of nattokinase medium was optimized by Plackett-Burman experiments, steepest climbing experiments and response surface methodology on the basis of single factor test. The results showed that soybean meal, CaCl2 and glycerol were screened as the main factors affected nattokinase activity by Plackett-Burman experiments. The optimal nattokinase fermentation medium was determined by response surface methodology as follows: glycerol 43 g/L, soybean meal 24 g/L, CaCl2 0.14 g/L, MgSO4·7H2O 0.80 g/L, Na2HPO4·12H2O 3.00 g/L, KH2PO4 1.00 g/L, L-methionine 0.20 g/L. Under the condition, the nattokinase activity was the highest of (4 281±103) FU/ml, which was 1.97 times that of before optimization.