解淀粉芽孢杆菌产凝乳酶发酵条件的优化

Optimizing the fermentation conditions formilk-clotting enzyme production by Bacillus amyloliquefaciens

为了进一步提高解淀粉芽孢杆菌(Bacillus amyloliquefaciens)发酵产凝乳酶的活力,采用单因素和正交试验设计,对影响解淀粉芽孢杆菌凝乳酶活力的培养温度、摇床转速、培养基初始pH及发酵时间等主要因素进行了优化组合试验,确定最佳发酵条件。结果表明:摇床转速对解淀粉芽孢杆菌凝乳酶活力影响最大,其次是发酵时间,培养基初始pH的影响较小。单因素和正交试验结果确定的最佳发酵条件为:在100mL三角瓶中装30mL发酵培养基,接种量3%,培养温度39℃,培养基最初pH为6.0,发酵时间为14h,摇床转速为120r/min,凝乳酶活力可达923.1Su/mL。

In order to improve the yield of milk-clotting enzyme activity（MCA）produced by Bacillus amyloliquefaciens,single factor and orthogonal test were applied to determine the optimum fermentation conditions.Culture temperature,vibration speed,initial pH and culture time were tested.The results showed that the main influence factor on MCA is vibration speed,then culture time and culture temperature.The optimum fermentation conditions were as follows：fermentation medium 30mL in a 100mL Erlenmeyer flask,inoculums size 3%,culture temperature 39℃,culture time 14h,initial pH of fermentation medium 6.0 and vibration speed 120r/min.Under the above optimal conditions,the MCA was 923.1 Su/mL.