青海可可西里嗜碱芽胞杆菌资源调查

Survey of alkaliphilic Bacillus-like resources in Kekexili, Qinghai

【目的】了解可可西里嗜碱芽胞杆菌资源多样性及产酶多样性,为芽胞杆菌功能资源挖掘和菌剂开发提供基础。【方法】采用Horikoshi I培养基,通过可培养法分离青海可可西里土壤中的嗜碱芽胞杆菌,利用16S r RNA基因序列初步鉴定分离获得的芽胞杆菌。采用透明圈法分析分离菌株的产蛋白酶、纤维素酶及木聚糖酶活性。【结果】从青海可可西里土壤中共分离获得66株嗜碱芽胞杆菌,根据16S r RNA基因序列相似性分析,发现它们隶属于6个属22个种,分别为芽胞杆菌属(Bacillus)、纤细芽胞杆菌属(Gracilibacillus)、喜盐芽胞杆菌属(Halobacillus)、咸海鲜芽胞杆菌属(Jeotgalibacillus)、类芽胞杆菌属(Paenibacillus)和嗜冷芽胞杆菌属(Psychrobacillus),其中以芽胞杆菌属(Bacillus)为优势属。2株嗜碱芽胞杆菌与它们最近匹配模式菌株的16S r RNA基因序列相似性为97.00%和98.65%,为潜在新种。三种酶活检测结果表明产酶菌株约占总分离菌株的95.00%,其中55株具有产蛋白酶活性,27株具有产纤维素酶活性,8株能够产木聚糖酶。【结论】青海可可西里蕴藏着较丰富的嗜碱芽胞杆菌资源及丰富的产酶资源,为后续嗜碱芽胞杆菌的挖掘提供理论基础。

[Objective] To provide a foundation for new resource mining of the alkalophilic Bacillus-like species and development of microbial agents, we studied the species distribution and diversity of Bacillus-like isolated from soil samples in Kekexili of Qinghai Province. [Methods] Alkalophilic Bacillus species were isolated from soil samples using the cultural method on Horikoshi I medium and preliminarily identified based on 16S rRNA gene sequences. Then, strains with ability of protease-, cellulases- and xylanase-producing activity were screened using transparent zone method. [Results] A total of 66 strains of alkalophilic Bacillus species were obtained and identified as 22 species belonging to 6 genera, Bacillus, Gracilibacillus, Halobacillus, Jeotgalibacillus, Paenibacillus, and Psychrobacillus, by 16S rRNA gene sequences similarities analysis. The genus Bacillus was the dominant bacteria. There were 2 new potential species of alkalophilic Bacillus with 16S rRNA gene similarities 97.00% and 98.65%, respectively. Three enzymes-producing strains accounted for 95.00% of all isolates, including 55 strains with protease activity, 27 strains with cellulase activity, and 8 strains with xylanase. [Conclusion] There were rich resources of alkalophilic Bacillus species and abundant enzyme-producing strains in Kekexili of Qinghai Province, which provided a great potential of exploitation of alkaliphilic Bacillus species.