中性蛋白酶产生菌的分离及产酶条件的研究

Study on screening and fermentation conditions of bacteria producing the neutral protease

针对牛奶废水中性、蛋白含量高的特点,利用只含脱脂奶粉和豆粕的选择培养基,从活性污泥中分离获得1株中性蛋白酶高产菌株S6,该菌株在pH7.2、35℃条件下经振荡培养40h,产蛋白酶活力达到1.113×103(U/mL),高于目前报道中性蛋白酶产生菌株的平均水平。最后依据伯杰氏鉴定手册对其进行初步鉴定,认为该菌株属于黄杆菌属细菌(Xanthobacter sp)。

In view of the fact that milk wastewater is neutral and rich in protein, one strain, named S6, were isolated and screened from activated sludge by selective medium comprised of defatted milk powder and soybean meal. Under the conditions of pH7.2, 35℃, the maximum enzyme activity reached 1.113×10^3（U/mL） after 40 h shake cultivation. This result is above the average level as reported. According to the Bergey＇s manual of systematic bacteriology, the S6 strain was identified as Xanthobacter sp.