一株盐芽孢杆菌的筛选及其粗酶的酶学特性研究  

Screening of a strain of Bacillus salicus and study on its enzymatic properties

作　　者：张辞海 曹凯 张家胜 武超[1] ZHANG Cihai;CAO Kai;ZHANG Jiasheng;WU Chao(College of Resources and Environmental Engineering,Anhui University,Hefei 230601)

机构地区：[1]安徽大学资源与环境工程学院,合肥230601

出　　处：《安徽农业大学学报》2020年第1期122-128,共7页Journal of Anhui Agricultural University

基　　金：国家自然科学基金(31670126);安徽省高校优秀青年人才支持计划项目(gxyq2018001);安徽大学高层次人才引进项目(01001770);安徽大学青年骨干教师培养项目(J01005132)共同资助。

摘　　要：从浙江舟山市双峰盐场中筛选出一株分泌蛋白酶的嗜盐菌,结合16S rDNA基因序列鉴定、菌株形貌特征确定其为特氏盐芽孢杆菌(Halobacillustrueperi)命名为HalobacillustrueperiB1。经研究,该菌株最适生长NaCl浓度为5%,表明其为中度嗜盐菌。该蛋白酶在50℃和pH 7.5条件下具有最高的蛋白酶活力。对发酵培养时间的优化实验表明发酵8 h后B1分泌的蛋白酶活力最大。对发酵培养基的优化结果表明,脱脂奶粉为最适氮源和碳源;75 g·L^-1为最佳发酵盐浓度,对钙镁离子的依赖不明显。确定优化后的发酵培养基:Na HCO30.06 g,KCl2.0g,CaCl2·2H2O0.48 g,Mg SO4·7H2O 1.0 g,FeCl3 0.001 g,NaCl 75.0 g,脱脂奶粉10.0 g。在初始pH 7.5,温度为40℃条件下发酵8 h。A phage-secreting halophilic bacterium was selected from the Shuangfeng salt field in Zhoushan city, Zhejiang Province. Combined with the 16 S rDNA gene sequence identification and strain morphology, it was identified as Halobacillus trueperi as Halobacillus trueperi B1. After research, the optimal growth of the strain was 5% Na Cl, indicating that it is a moderate halophile. The protease has the highest protease activity at 50℃ and pH 7.5. Optimization experiments on fermentation time showed that the protease activity secreted by B1 was the highest after 8 hours of fermentation. The optimization results of fermentation medium showed that skim milk powder was the most suitable nitrogen source and carbon source;75 g·L^-1 was the best fermentation salt concentration, and the dependence on calcium and magnesium ions was not obvious. The optimized fermentation medium was determined: NaHCO3 0.06 g, KCl 2.0 g, CaCl2·2 H2O 0.48 g, MgSO4·7 H2O 1.0 g, FeCl3 0.001 g, NaCl 75.0 g, skim milk powder 10.0 g. Fermentation was carried out for 8 h at an initial pH of 7.5 and a temperature of 40℃.

关 键 词：筛选 特氏盐芽孢杆菌 中度嗜盐菌 蛋白酶 发酵培养基 

分 类 号：X172[环境科学与工程—环境科学]