纳豆激酶液态发酵工艺的优化

Research on Liquid Fermentation Process of Nattokinase

对由纳豆芽孢杆菌(Bacillus natto)液体摇瓶发酵生产纳豆激酶的发酵条件进行优化,并对5L发酵罐放大工艺进行研究。结果表明:以4%(w/v)的可溶性淀粉作为碳源,种龄10 h,接种量3%(v/v),通气量0.5 vvm,发酵罐转速由220 r·min-1提升至700 r·min-1,使发酵罐中溶解氧保持在20%以上,以上条件更有利于纳豆激酶的表达。条件优化后,摇瓶中纳豆激酶的表达量由低于1 000 IU·m L-1,提高到2 051.3 IU·m L-1(以尿激酶活为标准)。

The liquid fermentation process of nattokinase was studied both in shake flask experiment and 5L fermentor. The results showed that the best condition was 4%（ w / v） soluble starch as carbon source,10 h bacteria age,3%（ v / v） inoculum concentration,0. 5 vvm ventilation,and the rotate speed of fermentor increased from 220 r·min^-1to 700 r·min^-1. All of those above could keep the dissolved oxygen in fermentor above 20%. After optimized,the expression quantity of Nattokinase in the shaker increased from lower than 1 000 IU·m L^-1to 2 051. 3 IU·m L^-1,equal to urokinase.