响应面法优化纳豆激酶液态发酵条件

Optimization of condition for liquid fermentation of nattokinase by response surface methodology

目的响应面法优化纳豆激酶液态发酵条件。方法以纳豆芽孢杆菌(Bacillus subtilis Natto)为出发菌株,液态发酵纳豆激酶。在单因素试验确定接种量、温度、初始pH及发酵时间对纳豆激酶活力产生影响的基础上,采用BoxBehnken软件进行响应面优化。结果最终确定纳豆激酶液态发酵的最佳条件为:接种量3%,温度40℃,pH 7.0,发酵时间84 h。在该条件下液态发酵生产纳豆激酶的活力可达749.41 U/ml,与模型预测的酶活力(752.35 U/ml)的相对误差为0.39%。结论成功优化了纳豆激酶液态发酵条件,为纳豆激酶的产业化生产奠定了基础。

Objective To optimize the condition for liquid fermentation of nattokinase by response surface methodology.Methods Bacillus subtilis Natto was subjected to liquid fermentation, and the effects of inoculum size, temperature, initial p H value and time for fermentation on the activity of produced nattokinase were evaluated by single factor experiment,based on which the condition for fermentation was optimized by response surface methodology. Results The optimal inoculum size, temperature, p H value and time for liquid fermentation of nattokinase were 3%, 40 ℃, p H 7. 0, and 84 h respectively. Under the optimal condition, the activity of nattokinase reached 749. 41 U/ml, of which the relative error to that predicted in model（752. 35 U/ml） was 0. 39%. Conclusion The condition for liquid fermentation of nattokinase was successfully optimized, which laid a foundation of industrial production of nattokinase.