枯草芽孢杆菌群β-甘露聚糖酶基因克隆及同源性分析

本文对33株枯草芽孢杆菌群菌株进行β-甘露聚糖酶活性筛选，其中的32株具有β-甘露聚糖酶活性，只有1株无β-甘露聚糖酶活性。通过基因克隆测序的方法获得33株枯草芽孢杆菌群菌株β-甘露聚糖酶基因编码区全序列，对酶基因进行同源性分析并构建系统发育树；在β-甘露聚糖酶基因系统发育树中，33株枯草芽孢杆菌群菌株聚为3个分支，分别是枯草芽孢杆菌分支、地衣芽孢杆菌分支和解淀粉芽孢杆菌分支；枯草芽孢杆菌、地衣芽孢杆菌和解淀粉芽孢杆菌β-甘露聚糖酶基因种内同源性大于91％，而种间同源性为60％～69％。

Cloning and Homology Analysis of Beta-mannanase Gene from the Collection of Bacillus s ubtilis Group

The beta-mannanase activity of thirty-three strains from the collection of Bacillus s ubtilis group were determinated in this study, the result revealed that thirty-two tested strains exhibited beta-mannanase activity as well as only one strain＇s beta-mannanase activity wasn＇t detected. The complete encoding sequences of beta-mannanase gene from thirty-three B. subtilis group strains were obtained by using gene cloning and sequencing, and the beta-mannanase gene homology was analyzed and a phylogenetic tree was generated. In the phylogenetic tree of the beta-mannanase gene, thirty-three B. subtilis group strains were clustered into three distinct clades, the B. subtilis clade, the B. licheniformis clade and the B.amyloliquefacieus clade. The homology of beta-mannanase genes from B. subtilis, B. licheniformis and B. amyloliquefaciens was above 91% at the intraspcies level, while the homology ranging from about 60% to 69% at the interspecies level, which could provide a gist for the classification and identification of Bacillus s ubtilis group strains.