台湾地区芽胞杆菌物种多样性

Diversity of Bacillus-like species in Taiwan

了解芽胞杆菌资源多样性,可为芽胞杆菌功能资源挖掘和菌剂开发提供基础。从台湾地区8个市(县)采集土壤样本,从20份土壤样品中分离获得了136株芽胞杆菌,采用16S rRNA基因同源性将其鉴定为芽胞杆菌科的2个属、20个种。分别属于芽胞杆菌属(Bacillus)的16个种和赖氨酸芽胞杆菌属(Lysinibacillus)的4个种。根据分离频度分析得知,台湾地区土壤中的芽胞杆菌优势菌群为阿氏芽胞杆菌(Bacillus aryabhattai)、苏云金芽胞杆菌(B.thuringiensis)和蜡样芽胞杆菌(B.cereus),其他种类分布极其不均匀。芽胞杆菌Shannon多样性指数为1.2925–2.5850,最高的为台中市和嘉义市(2.5850),最低的为桃园县(1.2925)。根据分离频度对芽胞杆菌种类的聚类分析显示,当欧式距离λ=20时,芽胞杆菌种类可分为高频度分布类型如阿氏芽胞杆菌(B.aryabhattai),低频度分布类型如简单芽胞杆菌(B.simplex)。依据分离频度对8个采样点间的聚类分析未发现采样点间的芽胞杆菌种类分布的相关性。本研究认为台湾地区土壤中蕴藏着丰富芽胞杆菌种类多样性高,具有很大的开发潜力。

To provide a foundation for new resource mining of Bacillus-like species and the development of microbial agents, we investigated the distribution and diversity of Bacillus-like species, which were isolated from soil samples collected in Taiwan. The Bacillus-like bacteria were isolated from the soil samples using the culturable method and preliminarily identified based on 16S rRNA gene sequences. A total of 136 Bacil- lus-like isolates were obtained from 20 soil samples, and identified as 20 species belonging to 2 genera （16 Bacillus species, 4 Lysinibacillus species） within Bacillaceae by 16S rRNA gene sequences. According to isolation frequency analysis, the dominant bacteria in Taiwan were B. aryabhattai, B. thuringiensis and B. cereus. Other bacteria were distributed extremely unevenly. In Taiwan, the Shannon-Wiener diversity index ranged from 1.2925 to 2.5850, with the highest values found in Taichung and Chiayi cities （both 2.5850）, the lowest in Taoyuan County （1.2925）. Based on isolation frequency cluster analysis, all the Bacillus-like spe- cies could be divided into high frequency groups and low frequency groups. Moreover, there was no correla- tion in the species distribution of Bacillus-like bacteria among the collection sites in Taiwan. Thus, Taiwan contains rich Bacillus-like species and high diversity, which has strong potential for exploitation in the future.