Compositional and Functional Characterization of Glycolipid Biosurfactants from an Olive-Derived Lactiplantibacillus plantarum

Abstract

Biosurfactants from lactic acid bacteria are attractive as safe, multifunctional ingredients for food and cosmetic applications, yet many remain only partially characterized. An olive-derived strain was identified as Lactiplantibacillus plantarum J2K-1229 by 16S rRNA gene and genome-based phylogeny. Grown in rapeseed oil-containing medium, it secreted extracellular material with surface/interfacial activity, and its cell-free supernatant emulsified diverse plant oils (emulsification index after 24 h, 26.67−41.33%). A purified biosurfactant fraction gave carbohydrate- and lipid-positive, ninhydrin-negative thin-layer chromatography and Fourier transform infrared bands of a hydroxylated, ester- and carboxylic acid-containing lipid. Gas chromatography, NMR, and HPAEC–PAD indicated a complex, lipid-dominant mixture with major oleic and palmitic acids, NMR signals consistent with co-extracted phenyllactic acid-type metabolites, and fructose as the only detected monosaccharide. Genome mining revealed glucosyltransferases for glucose-based glycolipids but no fructosyltransferase, suggesting that the detected fructose may represent co-extracted free fructose, possibly released as a glucansucrase by-product. The preparation inhibited Candida albicans in disk diffusion assays and was non-cytotoxic to RAW 264.7 macrophages and HaCaT keratinocytes up to 200 ppm. In lipopolysaccharide-stimulated macrophages it suppressed nitric oxide production (88.07% at 200 ppm) and inducible nitric oxide synthase expression, and in cytokine-stimulated keratinocytes it reduced TARC, MDC, and RANTES expression. Overall, this olive-derived L. plantarum produces a multicomponent, glycolipid-containing biosurfactant preparation with emulsifying, antifungal, and anti-inflammatory activities suited to cosmetic and personal-care applications.