Functional Genome Annotation of Lactiplantibacillus pentosus KMU32 Reveals Its Dual Potential as a Starter Culture and Probiotic from Traditional Korean Kimchi.

Abstract

This study evaluated the potential of Lactiplantibacillus pentosus KMU32, isolated from kimchi, as both a starter culture for fermented foods and a probiotic candidate by assessing its safety, enzymatic activity, health-promoting properties, and antimicrobial efficacy. Strain KMU32 exhibited susceptibility to seven antibiotics and showed neither hemolytic activity nor biofilm formation, indicating a favorable safety profile. Compared with the reference strain L. pentosus KACC 12428T, KMU32 demonstrated significantly enhanced growth and protease activity under saline conditions, maintaining robust growth and protease activity in media supplemented with 3% and 6% NaCl. KMU32 also exhibited stronger antibacterial activity than the reference strain against several foodborne pathogens, including Bacillus cereus, Enterococcus faecalis, Alcaligenes xylosoxidans, Escherichia coli, and Salmonella enterica. In addition, KMU32 showed improved probiotic-associated functional properties, including higher acid tolerance (94.38% survival at pH 2.5), bile salt tolerance (94.29% survival in 0.3% oxgall), and intestinal adhesion ability (98.47% mucin adhesion rate) compared with the reference strain. Whole-genome sequencing revealed that KMU32 possesses a 3,757,123-bp circular chromosome and three plasmids, with a G+C content of 46.2%. Genome analysis identified genetic determinants supporting its phenotypic traits, including three osmoprotectant uptake systems (OpuA, OpuB, and OpuD), four exopolysaccharide biosynthesis operons, and genes annotated as a putative bacitracin synthase and bacitracin export-related protein. Collectively, these phenotypic and genomic characteristics indicate that L. pentosus KMU32 is a safe and functionally robust strain with dual potential as a starter culture for high-salt fermented foods and as a probiotic candidate, supporting its promising application in the food industry.