Dissecting the High Esterase/Lipase Activity and Probiotic Traits in Lactiplantibacillus plantarum B22: A...

Lactiplantibacillus plantarum B22 exhibits a high esterase/lipase activity, but the genomic and probiotic potential remains unclear. We employed an integrated approach combining whole-genome sequencing, molecular docking studies, and phenotypic assays to dissect the genomic and functional basis underlying the high lipolytic activity and probiotic traits of L.plantarum B22. This strain exhibited a robust lipase activity (3.45 ± 0.13 U/mL), with whole-genome analysis revealing that the complete genome of this strain spans 2,027,325 bp, encoding 2005 genes with a guanine-cytosine (GC) content of 35.06%. Notably, 13 esterase/lipase genes were identified, 4 of which (gene3060, gene3059, gene2553, gene0798) harbor conserved catalytic triads (Ser-His-Gly/Ala), essential for lipase function. Molecular docking studies confirmed strong binding affinity to tributyrin (ΔG ≤ -5.52 kcal/mol) and elucidated the interaction mechanisms, involving hydrogen bonding and hydrophobic interactions between the esterase/lipase enzymes and tributyrin. Phenotypic and genomic analyses further demonstrated that L. plantarum B22 possesses excellent tolerance to simulated human gastrointestinal tract conditions, along with potent antioxidant and antimicrobial activities, highlighting its strong probiotic potential. Genomic annotation also identified 68 genes associated with lipid metabolism and an intact fatty acid synthesis pathway. Importantly, the analysis of phenotypes and genes involved in virulence factors, and the production of harmful metabolites suggests that L. plantarum B22 is safe. Collectively, this study offers novel insights into the genome-guided functional characterization of L. plantarum B22, providing a robust foundation for its development as a functional probiotic strain.