红曲米中凝乳酶产生菌的筛选及液态发酵条件的优化

Screening of the chymosin-producing strains from red kojic rice and its optimization of fermentation conditions

红曲米是我国古代流传下来的一种传统添加剂,红曲米中微生物所产凝乳酶具有凝乳作用。采用酪蛋白平板法和Arima时间法筛选出了1株产生凝乳酶能力强的菌株M5。通过正交试验,对该霉菌产凝乳酶发酵条件进行了初步优化,结果表明,PDA培养基是该霉菌产凝乳酶的最佳培养基,最佳培养条件为温度30℃、转速为160 r/min、振荡培养72 h,凝乳活力可达到150.6 SU。

Red kojic rice is a traditional food additive in China and the chymosin produced by microorganisms was proved to have the function of coagulating milk. A high chymosin producing strain, named M5 was screened through the Petri dishes method and Arima technique. In addition, the optimal fermentation conditions of M5 were obtained through orthogonal test as follows： potato medium, fermentation temperature 31℃ rotating speed 160 r/min, fermentation time 60 h. Under these conditions, the chymosin activity reached 150.6 SU.