Antimicrobial Activity of Bacillus sp. K-9 Against Potato Scab and Its Genome-wide Analysis

Abstract We isolated a bacterial strain K-9, identified as a novel species of the genus Bacillus, from a potato tuber sample. The inhibition rate of the strain K-9 against potato scab (Streptomyces scabies) was 44.90%. The whole genome sequence of Bacillus sp. K-9 was obtained, and genomic analyses were performed. Complete genome sequence of strain K-9 was obtained through PacBio RSII and Illumina platforms. The size of genome is 3891530 bp, with estimated 3915 coding DNA sequences, GC content of 46.45%, 79 tRNA, and 10 rRNA. In addition, functional annotation of the strain K-9 genes was performed by GO, COG, KEGG, and CAZy analyses. There were 12 gene clusters for secondary metabolite synthesis in the genome of Bacillus sp. K-9. Except for the unknown metabolites of the T3PKS (third polyketone), terpene and lanthipeptide class-II, the other eight gene clusters are associated with the synthesis of secondary metabolites that are common in Bacillus and have antibacterial activity. Among them, the homologous alignment function types are mostly related to the synthesis of antibacterial active substances such as PKS (polyketone synthase), NRPS (non-ribosomal peptide synthase) and bacilysin. In the future, information derived from the thorough genomic analyses of this strain may be helpful in directed genetic modification of bacterial strains for production of antibacterial substances to control potato scab.