一株蛋白酶产生菌的分离鉴定

Screening and identification of microorganism producing protease

从郑州奶牛场土壤样品中分离到一株芽孢杆菌,命名为A-19菌株。该菌株有较高的蛋白酶活性,37℃、pH7.0培养48h后,其蛋白酶活力可达63.5U/mL。菌体生长专性需氧,有运动性,粗糙型菌落,氧化酶试验阳性,DNA(G+C)的摩尔分数为47%。该菌株的16S rD-NA序列与芽孢杆菌属有很高的同源性,Bacillusvallismortis(99.61%),B.subtilis(98.81%),B.amyloliquefaciens(98.95%),B.licheniformis(97.93%)。通过其生理生化特征和16S rDNA序列相似性的系统发育分析,确定A-19菌株属于芽孢杆菌属。该菌的16S rDNA序列已被GenBank收录,序列登陆号为EU561347。

An endospore-forming bacterium, designated strain A-19,was isolated from a milk cow field sample in Zhengzhou. It presents remarkable protease activity. The strain was strictly aerobic, motile, spore forming and rod shaped,oxidase-positive. The DNA （G＋C） content was 47 %. Strain A-19 exhibited high 16S rDNA similarity with its closest neighbors.Bacillus vallismortis （99.61% ）, B. subtilis （98.81% ）, B.amyloliquefaciens （98.95 %）, B. licheniformis （97.93 %）. The phenotypic and genotypic characteristics indicate that strain A-19 belongs to the genus Bacillus. Its protease activity was 63.5 U / mL at 37 ℃、pH7.0. The GenBank accession number for the sequence reported in this paper is EU561347.