一株源于红树林土壤芽孢杆菌的鉴定及其蛋白酶学性质研究

从湛江红树林土壤中分离出一株产蛋白酶的芽孢杆菌，通过细菌形态观察、生理生化试验及16S rRNA基因序列进行分类鉴定，并研究了温度、pH 值、金属离子、EDTA 和吐温80 等因素对该菌株发酵产蛋白酶的酶学性质的影响。结果表明，该菌株为解淀粉芽孢杆菌，命名为解淀粉芽孢杆菌y-6（Bacillus amyloliquefaciens strain y-6）；该菌株产生蛋白酶的最适温度为55益，最适pH 为7.0~7.5，40益时，酶活性稳定，保温3 h仍有95%以上的相对酶活力，pH 为5.5~11 时，酶活性稳定，相对酶活力均在90%以上；Ca2+、Zn2+和吐温80 对蛋白酶有一定的激活作用，Mn2+、Fe3+、Cu2+及EDTA 对酶有一定的抑制作用，其中EDTA 对酶的抑制作用最强。

Study on identification and protease propertiesof a bacillus isolated from mangrove soil

A strain of bacillus which could produce protease was isolated from soil sample collected from a chickenfarm, and was identified by the observation of its morphology, culture characteristics and the analysis of 16S rRNAsequence. The properties of protease excreted by isolate fermentation were studied with different temperature, pH, metalion, EDTA and Tween 80. Results showed that, the isolate belonged to Bacillus amyloliquefaciens, and was named Bacillusamyloliquefaciens strain Y-6, the optimal reaction temperature of protease produced by strain Y-6 was 55, the optimalreaction pH was 7.0~7.5. The protease activity was steady at 40 and at pH 5.5~11, the relative enzyme activity was morethan 95% at 40 for 3 h, and was more than 90% at pH 5.5~11. The protease activity could be activated by Ca2+, Zn2+ andTween 80, but inhibited by Mn2+, Fe3+, Cu2+ and EDTA which had the biggest inhibition effect.