Complete genome sequence of Bacillus velezensis NST6 and comparison with the species belonging to operational group B. amyloliquefaciens

Abstract

Bacillus spp. play important roles in production of bioactive natural products with potential agricultural and medical applications. The three families of lipopeptides produced by Bacillus spp. have been most recognized for their antagonistic activity against other microbes, i.e. fengycin, iturin, and surfactin. A novel strain NST6 was isolated from soil and identified as B. velezensis based on phylogenomic analysis. Genome analysis revealed 21 putative biosynthetic gene clusters including the ones responsible for producing bacillomycin and surfactin. However, fengycin cluster was compromised with absence or partial disruption of three non-ribosomal peptide synthetases. Distribution of biosynthetic gene clusters showed that clusters for iturin families were well conserved in 327 genomes of the species belonging to the operational group B. amyloliquefaciens. However, clusters for fengycin and surfactin showed dynamic distribution at gene level. Comparative analysis of closely related species would provide new insights to the diversity in genetic elements for secondary metabolites.

Keywords: Bacillus velezensis NST6; Biosynthetic gene cluster; Comparative genomics; Lipopeptide.