【摘要】 以纳豆菌B-12为出发菌株,对其液体发酵产纳豆激酶的条件及纳豆激酶部分酶学性质进行了研究。实验研究了碳源、氮源、接种量、发酵时间、发酵温度和培养基初始pH值对纳豆菌B-12产酶的影响,在优化发酵条件下,纳豆菌B-12产酶量相当于尿激酶903IU/mL。纳豆激酶在50℃,热稳定性较好,保温100min残余酶活力保持80%左右;在pH6.0~9.0较稳定,残余酶活力保持在近80%左右;金属离子Fe3+、Al3+对纳豆激酶有明显的抑制作用,Zn2+有微弱的促进作用。更多还原

【Abstract】 The conditions of producing nattokinase by Bacillus natto strain B-12 and the partial enzyme properties of nattokinase were researched,and the effects of carbon source,nitrogen source,fermentation time,fermentation temperature and original media pH on production of nattokinase were investigated in this paper.Based on optimized conditions for fermentation,the yield of nattokinase by Bacillus natto strain B-12 was 903 IU Urokinase/mL. Nattokinase was stable, and the residual activity was about 80 % at 50 ℃ for 100 min. It was also stable in pH6.0-9.0,and the residual activity was about 80 %. Fe3+ and Al3+ could obviously inhibit enzyme activity,and Zn2+ could faintly activate the activity.更多还原