Whole-genome sequencing coupled with functional and safety validation reveals the probiotic and antimicrobial potential of traditional curd–derived Lactiplantibacillus plantarum
摘要
Growing interest in natural formulations for food and health applications has intensified research on probiotic lactic acid bacteria (LAB). In this study, a LAB strain designated MIC-3 was isolated from traditional curd and evaluated using phenotypic, safety, and whole-genome approaches. The isolate exhibited typical LAB characteristics, being Gram-positive and catalase-negative with broad carbohydrate fermentation ability. MIC-3 demonstrated moderate broad-spectrum antimicrobial activity, with inhibition zones up to 8.7 mm against selected pathogens. The strain was susceptible to clinically relevant antibiotics and displayed γ-hemolytic activity, confirming its safety profile. It maintained viability under acidic conditions and tolerated bile salt concentrations up to 0.8%. Adhesion-associated properties were significant, with 85% auto-aggregation, strong co-aggregation with pathogens, and high cell surface hydrophobicity. Whole-genome sequencing identified the strain as Lactiplantibacillus plantarum and revealed genes supporting probiotic functionality, including stress tolerance (atp operon, groEL/groES, dnaK, clp), bile resistance (bsh/cbh, ABC transporters), adhesion (srtA, slpA, eps clusters), and bacteriocin production (pln cluster). Genes involved in lactic acid production, carbohydrate uptake, and vitamin biosynthesis were also detected, while no virulence-associated genes were identified. Collectively, these findings confirm the probiotic and functional potential of L. plantarum MIC-3 for food and health applications.