一株高温蛋白酶高产菌株产酶条件的优化  

Optimization of fermentation medium and culture condition of a thermostable protease from moderate thermophilic strain Bacillus subtilis BY25

作　　者：朱泓[1,2,3] 王一明[1] 林先贵[1] 

机构地区：[1]中国科学院南京土壤研究所,土壤与农业可持续发展国家重点实验室,江苏南京210008 [2]江苏省.中国科学院植物研究所,江苏南京210018 [3]中国科学院大学,北京100049

出　　处：《南京林业大学学报（自然科学版）》2014年第1期31-35,共5页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：中国科学院知识创新工程项目(KSCX2-EW-N-08);国家林业局"948"项目(2011-G25)

摘　　要：对一株高温蛋白酶高产菌株枯草芽孢杆菌BY25的发酵培养基组成与产酶条件进行了优化。正交试验结果显示培养基中各因子对产酶影响从高到低为：豆饼粉、葡萄糖、硫酸镁、麸皮、磷酸氢二钠、氯化钙。在此基础上进行培养基组成优化，将豆饼粉、麸皮混合氮源改为以豆饼粉为单一氮源进行蛋白酶发酵。单因素试验发现，在单一氮源培养条件下，培养基中各因子对产酶影响从高到低依次为：豆饼粉、葡萄糖、氯化钙、磷酸氢二钠。除微量氯化钙外，金属盐，尤其是金属硫酸盐的添加对产酶有显著抑制作用。此外，培养初始pH和培养时间对产酶有显著影响，接种量也有一定影响。通过绘制120h产酶曲线发现，BY25产酶曲线为双峰，产酶曲线顶峰出现在发酵后72h，优化后BY25发酵培养基各组分添加量为豆饼粉60/L、葡萄糖60g／L、氯化钙0．5g／L、磷酸氢二钠4/L，接种量为4．5％～5％，初始培养pH为8．0。优化产酶培养基和产酶条件后，发酵液酶活力可达到101．μmol／（min·mL）。The fermentation media components and culture conditions of the thermostable protease from a thermophilic strain Bacillus subtilis BY25 were further studied. A six factor and three level orthogonal experiment was conducted to ob- serve the effects of fermentation medium components on thermostable protease yield. Wheat bran was replaced by soybean cake powder for its low contribution rate. Single factor experiment was carried out to optimize the protease production. The optimized culture condition was at 30 ~C, with initiating pH of 8.0, 4.5%-5% inoculum size for 72 h; and the opti- mized fermentation medium components were described as follows： glucose 60 g/L, soybean cake powder 60 g/L, Na2HPO4 4 g/L and CaC12 0.5 g/L. After fermentation, the casein hydrolysis activity of the enzyme was estimated up to 101.1 μmot/（ min.mL）, much higher than other domestic reports.

关 键 词：枯草芽孢杆菌BY25 高温蛋白酶 培养基 产酶条件 

分 类 号：Q939.96[生物学—微生物学]