一株产低温蛋白酶芽胞杆菌FJAT-24893的筛选与鉴定

Screening and Phylogenetic Analysis on A Protease-producing Bacillus Species

为了解西藏尼玛县甲热布错湖及其周边土壤的微生物多样性,研究低温蛋白酶的高效生产生物技术,采用温度梯度法和稀释法,NA平板涂布分离可培养芽胞杆菌,通过酪素培养基筛选产蛋白酶的耐低温菌株,对甲热布错湖耐低温菌进行分离,并对其中的产低温蛋白酶菌株进行筛选,分析分离菌株生理生化特征、最适产酶条件,结合16SrRNA基因序列同源性分析确定产低温蛋白酶菌株的多样性和系统进化地位。从获得的16株分离物中筛选到1株产低温蛋白酶芽胞杆菌菌株FJAT-24893,经16SrRNA鉴定为耐寒芽胞杆菌(Bacillus frigoritolerans)。该菌株最适产酶温度为25℃、最适pH为8。

Bacteria isolated from the soil around a lake in Xizang（Tibet）,China were studied.Physiological and phylogenetic analysis were conducted to understand the diversity and ecological distribution of the psycrotrophic and psycrophlic populations in the area.On NA media,the collected cold-adapted strains of bacteria that produced protease were cultured.Their taxonomic identity and genetic variability were determined according to their partial16 SrRNA gene sequences.Of the 16 isolates,FJAT-24893 was found to exhibit a high protease activity.It was subsequently identified as Bacillus frigoritolerans.The optimal protease-producing conditions for culturing the strain were determined to be 25℃and pH8.