选用两种不同来源的枯草杆菌中性蛋白酶与木瓜蛋白酶,以水解度为特征性指标,采用5种不同水解方式水解牛骨蛋白。结果表明:枯草杆菌中性蛋白酶与木瓜蛋白酶同步水解,效果优于木瓜蛋白酶与枯草杆菌中性蛋白酶分步水解两种方式,最佳酶体系反应条件为pH7.05、温度51℃、加酶总量7000U/g(枯草杆菌中性蛋白酶与木瓜蛋白酶用量比1:1)、150r/min振荡水解6h,水解度可达27.54%。
Two proteases including Bacillus subtilis neutral protease and papain are used to hydrolyze bovine bone protein by five hydrolysis methods. The optimal dual-enzyme hydrolysis conditions of bone protein were explored for maximizing hydrolysis efficiency. The results indicated that synchronous hydrolysis of bone protein exhibited a higher hydrolysis effi- ciency when compared with the sequential hydrolysis by papain first and then Bacillus protease or Bacillus protease first and then papain. The optimal hydrolysis conditions were total enzyme amount of 7000 U/g at papain-neutral protease ratio of 1:1, oscillation hydrolysis time of 6 h, oscillation speed of 150 r/min, hydrolysis temperature of 51℃, hydrolysis pH of 7.05 and substrate concentration of 10%. Under the optimal hydrolysis conditions, the degree of hydrolysis was up to 27.54%.