米曲霉发酵产纤溶酶培养基的优化

OPTIMIZING THE MEDIUM OF ASPERILLUS ORYZAE STRAINS FOR PRDOUCING FIBRINOLYTIC ENZYME

通过单因素实验确定米曲霉NA-25产纤溶酶的最佳碳源为麸皮,最佳氮源为蛋白胨和NaNO3.利用SAS软件的Placket-Burman设计法对米曲霉NA-25产纤溶酶的培养基组成进行筛选,筛选出3个影响较大的重要因素,即蛋白胨、NaNO3、CaCl2,然后用中心组合实验设计进一步优化,经优化后,在上述因素分别为NaNO318.5 g/L,蛋白胨4.97 g/L,CaCl21.63 g/L时发酵液的酶活为98.13 U/mL,比原来提高了55.8%.

The result of single factor experiments showed that the optimal carbon source for Asperillus Oryzae NA-25 to producing fibrinolytic enzyme was bran and the optimal nitrogen source was peptone and NaNO3. Plackett - Burman design was undertaken to evaluate the effects of six factors. By the statistical regression analysis, the significant factors affecting the fibrinolytic enzyme activity in fermentation liquor were determined as follows： NaNO3, peptone, CaCl2. A central composite design and response surface methodology （RSM） were used to optimize the above critical internal factors, the optimal concentration of the variables were determined as ： 18.5 g/L NaNO3, 4. 97 g/L peptone,1.63 g/L CaCl2. In the optimal fermentation conditions the fibrinolytic enzyme activity in fermentation liquor was 98. 13 U/mL , increased by 55.8%.