Isolation and diversity analysis of Bacillus-like species from Bamen Bay mangrove soil

Abstract:

[Objective] Analyze microbial diversity of Bacillus-like group isolated from soil samples in Excoecaria agallocha forest, Bamen Bay mangrove. [Methods] The low dilution soil suspensions with heat shock treatment and the high dilution soil suspensions without heat treatment were spread onto Petri dishes for isolating Bacillus-like group species selectively. Their genetic diversity and phylogeny were characterized by 16S rDNA PCR-RFLP and 16S rDNA sequence analysis. [Results] In the level of 100% similarity, UPGMA of 16S rDNA PCR-RFLP map showed that 155 isolates were grouped into 21 clusters, which presented abundant genetic diversity. Moreover, 16S rDNA sequence analysis of representative strains of 21 clusters proved that they were distributed in four genera, Bacillus, Halobacillus, Virgibacillus and Paenibacillus, in which Bacillus was the dominant one. Based on the comparison of 16S rRNA gene sequences, the high levels of 16S rRNA gene similarities of eight strains with the corresponding type strains ranged from 95.1% to 99.0%. [Conclusion] Cultivable Bacillus-like group species isolated from Bamen Bay mangrove soil revealed high genetic diversity and there existed some new species.