一株产耐盐碱性蛋白酶菌株的分离鉴定及最佳生产条件研究

Isolation,identification and optimal production conditions of salt-alkaline resistant protease produced by one strain

目的:从腌制食品宣威火腿中分离产蛋白酶菌株,对其进行鉴定并研究其产酶条件及酶学性质。方法:应用脱脂奶培养基分离产蛋白酶菌株,经生理生化和分子生物学鉴定,然后采用单次单因子法优化其产酶条件,研究其所产酶的特性。结果:分离得到一株高产蛋白酶菌株XW-4,属于芽孢杆菌属。最优的产酶条件是:蛋白胨10 g/L、葡萄糖10 g/L、KH_2PO_41 g/L、Mg SO_4·7H_2O 0.05 g/L的标准培养基(pH 10.0),然后在37℃150 rpm发酵。结论:所产酶属耐盐的碱性钙离子依赖型金属蛋白酶,最适pH和最适温度分别是10.0和50℃。

Objective:To isolate and identify protease producing bacteria from the preserved food Xuanwei ham,and to authenticate and study the conditions for enzyme production and enzymatic properties.Methods:Protease strains were separated by skimmed milk medium,and identified by physiology,biochemistry and molecular biology,with the conditions for enzyme production optimized by using the single-factor method and the characteristics of the produced enzyme studied.Results:A strain of high-yield Protease XW-4 was produced by separation,belonging to the genus Bacillus.The optimal conditions for enzyme production were peptone 10 g/L,glucose 10 g/L,KH2PO4 1 g/L and MgSO4·7H2O 0.05 g/L standard culture medium(pH10),leavened at 37℃and 150rpm.Conclusion:The produced enzyme is an alkaline calcium-dependent metalloproteinase,and the optimal pH and temperature are 10 and 50℃respectively.