Abstract:

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 Bacillus-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 species could be divided into high frequency groups and low frequency groups. Moreover, there was no correlation 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.

Key words: Bacillus, Taiwan, 16S rRNA gene, diversity, species distribution