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

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.

Automated summary

Bacillus spp. are important in producing bioactive natural products with agricultural and medical applications, especially the lipopeptides fengycin, iturin, and surfactin with antagonistic activity against other microbes. A novel strain NST6 identified as B. velezensis has 21 putative biosynthetic gene clusters, including those responsible for bacillomycin and surfactin. Analysis shows that gene clusters for iturin families are well conserved in B. amyloliquefaciens species, while clusters for fengycin and surfactin have dynamic distribution at gene level.