响应面法优化纳豆激酶固态发酵培养基

Optimization of natto-kinase production on solidstate fermentation culture medium by response surface analysis

为优化以菜籽粕与麸皮为基质产纳豆激酶培养基组成,在单因素实验基础上,选择不同速效氮源、速效碳源、无机盐的种类及其添加量为自变量,纳豆激酶酶活为响应值,利用Box–Behnken中心组成设计原理,设计三因素三水平响应面试验,建立回归模型。经响应面分析,回归模型具有较高拟合度。结果显示优化后培养基组成为:菜籽粕∶麸皮(W/W)=1∶4基础培养基中,尿素添加量0.61 g/100g,葡萄糖添加量1.28 g/100g,氯化镁添加量0.64 g/100g,在初始pH 7.0,温度37℃条件下发酵48 h,纳豆激酶酶活达到7 329.76I U/g,较基础发酵培养基提高1.73倍。

Response surface methodology was used to optimize the fermentation culture medium for the production of Natto-kinase with the Rapeseed meal and wheat bran as the substrate. Combine with the single factor test, the mathematical regression model was established by selecting the response value （ yield of Natto-kinase ） and independent variables （ available inorganic salt, carbon sources and nitrogen sources ） through Box-Benhnken center combined method for the testing design of three- factor and three-level and doing response surface analysis. According to analysis, regression equation fitting is good and the optimal fermentation conditions for Predicted results indicated that Natto-kinase activity was 7 329.76I U/g after the fermentation of 2 days with the ratio of rapeseed meal to wheat bran was 1 ： 4,0.61% of urea as nitrogen sources, 1.28% of glucose as carbon sources, 0.64% of MgCl2 as inorganic salt and initial pH 7.0.