Comprehensive Evaluation of Safety and Probiotic Potential of Lactiplantibacillus plantarum HY7715 Isolated from Korean kimchi.

Lactiplantibacillus plantarum HY7715, isolated from Korean kimchi, has been previously reported to overproduce riboflavin in vitro and in vivo, indicating its functional potential as a probiotic candidate. Given this characteristic, a comprehensive safety and genomic evaluation is required prior to application. In this study, we assessed the safety, genomic stability, and probiotic-related properties of HY7715 through whole-genome sequencing, comparative genomics, and phenotypic analyses. The genome (3,348,486 bp; 44.29% GC content) was assembled into seven contigs and encoded 3,224 protein-coding sequences, of which 2,933 functionally annotated. No virulence factors or acquired antimicrobial resistance genes were detected, and mobile genetic elements did not harbor undesirable determinants. Although phenotypic resistance to kanamycin was observed, the absence of corresponding resistance genes indicates intrinsic resistance. HY7715 also exhibited γ-hemolysis and lacked genes associated with cytotoxic secondary metabolites or biogenic amine production. The rib operon was identified in the genome, and in silico analysis of the FMN riboswitch region revealed a unique nucleotide substitution potentially affecting regulatory conformation, which may contribute to the riboflavin-overproducing phenotype. Comparative pangenome analysis of 60 L. plantarum genomes revealed that HY7715 shares a conserved genomic backbone dominated by core and soft-core genes. Genes associated with stress tolerance, adhesion, carbohydrate utilization, and bacteriocin production were identified, consistent with probiotic-related traits. Collectively, these findings indicate that HY7715 is a genomically stable and safe strain with regulatory features supporting its functional probiotic potential.