Complete genome sequencing and strain characterization of a novel marine Bacillus velezensis FTL7 with a potential broad inhibitory spectrum against foodborne pathogens.

Bacillus velezensis FTL7 which exhibited potent antimicrobial peptide producing capacity was isolated from a marine sediment sample of the West Coast region, South India, and characterized through experimental and genomic analysis approaches. FTL7 showed potential antimicrobial activity against a broad range of foodborne pathogenic bacteria like Listeria monocytogenes Scott A, Bacillus cereus (ATCC 11778), Salmonella Typhimurium (MTCC 1251), Staphylococcus aureus (ATCC 25923), and Escherichia coli (MTCC 443). It also exhibited strong inhibitory activity against Kocuria rhyzophila (ATCC 934) and Bacillus subtilis subsp. spizizenii (ATCC 6633). Phylogenetic analysis by 16S rRNA gene sequence showed that Bacillus velezensis FTL7 was closely related to B. velezensis LBUM288 (GenBank accession number MG461457) with 100% identity. Whole-genome sequencing of the strain FTL7 was carried out using Illumina sequencing technology to get a better insight into the mechanisms of controlling pathogens by FTL7. The strain FTL7 has a chromosome size of 3849,077 bp with a GC content of 46.56%. The genome consists of 3635 coding sequences, 64 RNA, 59 tRNAs, 5 ncRNAs, and 69 pseudogenes. The presence of genes responsible for the synthesis of non-ribosomal peptides and bacteriocins was identified through genome annotation. Thus, many Bacillus strains, including B. velezensis, have been demonstrated as excellent producers of antimicrobial substances.