松毛虫肠道产蛋白酶菌株的筛选鉴定及培养条件研究

Screening and Identification of Protease-producing Bacterium from Intestinal Canal of Dendrolimu and Liquid Culture Studies

为了获得产蛋白酶能力高的细菌资源,采用酪蛋白平板法从松毛虫肠道中分离筛选得到16株产蛋白酶的菌株。通过比较透明圈大小和测定发酵后酶活力,筛选出一株产酶能力较高的菌株2N01。根据序列比对结果,构建关于2N01的系统发育树,将其鉴定为Enterobacter hormaechei。研究培养条件对该菌株生长的影响,确定2N01产酶培养的最适温度是40℃,最适pH8.0,培养72h左右出现产酶峰值,酶活力达50.07U/mL。通过研究表明,菌株2N01是产蛋白酶的较好材料,具有一定的应用前景。

In order to breed high-yield strains for protease, sixteen protease-producing strains were isolated from intestinal canal of Dendrolimu houi by casein plate. 2N01 was screened as a higher-yield strain for protease by comparing the size of transparent circle and enzyme activity. A phylogenetic tree was constructed with the published 16S rDNA sequences of relative bacteria species. In the phylogenetic tree, the strain 2N01 was in the branch with the Enterobacter hormaechei CIP 103441T （AJ508302）. The most suitably culture conditions for the growth of strain 2N01 was temperature 40℃ and pH 8.0. The highest protease activity of strain 2N01 was 50.07 U/mL when grown for 72 h. This study provided a good experimental material for the further industrial utilization about protease production.