耐热蛋白酶产生菌的筛选鉴定及其酶学性质研究

Isolation and identification of a strain producing thermostable protease and studying on its enzymatic properties

从云南大理市弥渡县白总旗热泉的55℃底泥中筛选到1株高温蛋白酶的高产菌株,进行显微形态及生理生化特征、16S rRNA基因序列分析,将其初步鉴定为短杆菌属(Brevibacillus sp.)的一株菌,命名为Brevibacillus sp.Pro-55。对其生长条件及酶学性质进行研究,结果表明:该菌株耐高温性较好,菌株在55℃仍能生长,菌株最适生长温度为43℃。所产蛋白酶最适酶活温度为40℃,最适反应pH为6.0。该酶在25℃以下,能保持良好的稳定性。Mn2+、K+、Fe2+对该酶有一定的抑制作用,Zn2+、Ca2+、Mg2+、Cu2+均对该酶活力起到促进作用,其中Cu2+的促进效果最为显著。

A high-temperature protease-producing strain was screened from the sediment of hot springs in Baizongqi,Dali County,Yunnan Province,and its morphology,physiological and biochemical characteristics,16S rRNA gene sequence analysis were carried out.The strain was identified as a strain of Brevibacillus sp.,and named as Brevibacillus sp.Pro-55.The growth conditions and enzymatic properties of the strain were studied.The results showed that the strain was resistant to high temperature and could still grow at 55℃.The optimum growth temperature was 43℃.The optimum protease temperature for protease production was 40℃,and the optimum reaction pH was 6.The enzyme could maintain good stability under 25℃.K+,Mn2+and Fe2+had a certain inhibitory effect on the enzyme.Ca2+,Zn2+,Mg2+,Cu2+all played a role in promoting the activity of the enzyme,of which Cu2+was the most obvious.