纳豆激酶的液体发酵条件优化

Condition Optimization of Nattokinase Liquid Fermentation

以纳豆素中分离的纳豆芽孢杆菌进行纳豆激酶发酵试验,考察装液量、接种量、摇床转速等因素对生物量和纳豆激酶纤溶活性的影响,揭示产酶规律并确定最优产酶条件。发酵培养基配方为2%葡萄糖、2%蛋白胨、0.05%Mg SO4、0.01%Ca Cl2、0.6%Na2HPO4、0.4%Na H2PO4。最终确定的发酵条件为：p H 6.9,2%接种量,45 m L/250 m L的装液量,33.5℃,摇床转速为165 r/min,在此条件下发酵33~34 h为产酶高峰期,纳豆激酶的纤溶活性达到1 004 U/m L,结果也表明纳豆激酶是一种生长关联型代谢产物,纤溶活性与生物量变化趋势高度一致。

Bacillus subtilis natto isolated from natto starter was used for natto fermentation. The effect of loading volume, inoculating volume, rotation speed of the shaker etc. On the biomass and the fibrinolytic activity of nattokinase was studied to reveal the principle and to optimize the fermentation conditions. The medium for nattokinase fermentation contained 2% glucose, 2% peptone, 0.05% MgSO4, 0.01% CaCl2, 0.6% NazHPO4 and 0.4% NaH2PO4. The determined fermenting condition was pH 6.9, 2% inoculating volume, 45 mL/250 mL loading volume, 33.5 ℃, with a rotating speed of 165 r/min. Under these condition, the enzyme production peak appeared at 33-34 h, and the fibrinolytic activity of the nattokinase reached to 1 004 U/mL, and the results also indicated that the nattokinase was a growth correlated metabolite, the fibrinolytic activity and the biomass of the cell was highly correlated and showed the same tendency during the fermentation.