纳豆芽孢杆菌配伍发酵产中性蛋白酶的性质研究

A Study on Neutral Ptotease Characterization of Ferments by Bacillus natto Compatibility

为研究纳豆芽孢杆菌SH和B1配伍发酵产物中中性蛋白酶的性质,通过Folin-酚法测定中性蛋白酶的最适作用温度、最适作用pH值、pH稳定性、热稳定性和金属离子、表面活性剂、抑制剂、模拟胃肠道环境对酶活力的影响,绘制相对酶活力变化图。结果表明:该酶的最适作用温度为70℃,最适作用pH为11.0,其次是pH为7.0,40℃时热稳定性较好,在pH6～7时比较稳定,属中性蛋白酶。金属离子、抑制剂和模拟胃环境对酶有抑制作用,而10g/LTween-80和模拟肠道环境对酶有激活作用。

The purpose is to study the enzyme characterizations of neutral protease fermented by synergism strains of Bacillus natto SH and B1.The optimal reaction temperature,optimal reaction pH,pH stability,thermal stability,metal ions,surface-active agent,inhibiter,simulated intestinal environment on enzyme stability were determined by Folin-phenol method,diversify graphs of residual activity were drawed.The results showed that the optimal reaction temperature of protease was 70 ℃,the optimal pH was 11.0,the next was 7.0.The thermal stability of protease was high at 40 ℃,and stable from pH 6 to 7,belonging to neutral protease.The protease activity was inhibited by metal ions,inhibiter and simulate stomach environment,but stimulated by 10 g/L Tween-80 and simulate intestinal tract environment.