Complete genome sequence of bacteriocin-producing Lactococcus lactis subsp. lactis DOME 6301 with potential oral-pathogen control applications.

Abstract

Lactococcus lactis subsp. lactis DOME 6301, isolated from bovine milk, produces an antimicrobial compound that inhibits oral pathogens including Streptococcus mutans, Prevotella intermedia, and Fusobacterium nucleatum. The entire genome of L. lactis DOME 6301 was sequenced and assembled de novo using the PacBio RS II platform. The genome was 2,532,858 bp in length, assembled into three contigs, and had a guanine and cytosine (G + C) ratio of 35%. The annotation results revealed 2,469 protein-coding sequences, 22 rRNA genes, and 78 tRNA genes. Genes involved in the utilization of complex carbohydrates (i.e., cellulose, xylose, pullulan, amylose, maltodextrin, and arabinofuranose) and synthesis of the bacteriocin, nisin Z, were detected. In addition, genes encoding antimicrobial resistance and virulence factors (i.e., hemolysin and enterotoxin) were detected. Whole-genome analysis of strain DOME 6301 contributed to our understanding of the evolution of the taxa and provided the basis for the correct selection of probiotic candidates for downstream applications.