产碱性蛋白酶海洋菌的诱变及其酶学性质的初步研究

[目的]筛选出高产碱性蛋白酶的菌株,为其在生产中的应用提供依据。[方法]从青岛沿海海域采集的海水及海泥中分离得到产碱性蛋白酶的菌株,经紫外诱变和微波诱变处理,获得目标菌株并测定菌株的酶活力,同时对诱变菌株的酶学性质进行初步的研究。[结果]筛选出的菌株酶活力为145 U/ml,经过复合诱变后,菌株ZR-58-3-1-3发酵液的酶活力达775 U/ml,比出发菌株高4.3倍。菌株所产碱性蛋白酶的最适反应温度为45℃,属中温蛋白酶;最适作用pH为8.5,具有较高的热稳定性。[结论]菌株ZR-58-3-1-3产碱性蛋白酶的性能稳定,可作为产碱性蛋白酶的突变菌株。

Mutagenesis of Alkaline Protease-Producing Marine Strain and Enzyme Properties

[Objective] The aim of the research was to select alkaline protease-producing strains and provide basis for the application in production.[Method] An alkaline protease-producing strain was isolated from the sea water and sea mud collected from Qingdao coastal area.After ultraviolet mutagenesis and microwave mutagenesis,a target strain ZR-58-3-1-3 was obtained.The enzyme activity and enzyme properties of the strain were determined preliminarily.[Result] Enzyme activity of the selected strain reached 145 U/ml.After the compound mutagenesis,enzyme activity of the fermentation liquid of strain ZR-58-3-1-3 reached 775 U/ml,which was about 4.3 times higher than that of the original strain.The optimal temperature for alkaline protease produced by strain ZR-58-3-1-3 was 45 ℃,and the optimal pH was 8.5,suggesting that it belongs to moderate temperature protease with relatively high thermal stability.[Conclusion] Strain ZR-58-3-1-3 has stable alkaline protease production performance and can be used as an alkaline protease-producing mutant strain.