Lactic acid bacteria-derived biosurfactants: emerging strategies for biofilm control, virulence attenuation, and food safety.

Biofilm-associated infections caused by multidrug-resistant bacteria and fungi impose a substantial global health burden, and conventional antibiotics are increasingly ineffective at eradicating them due to poor penetration of the extracellular polymeric substance (EPS) matrix and escalating resistance. Biosurfactants produced by lactic acid bacteria (LAB) have attracted research interest as alternatives, owing to the GRAS status of their producing organisms and their broad mechanistic repertoire. This review critically evaluates the structural diversity of LAB-derived biosurfactants, covering glycolipids, lipopeptides, glycoproteins, lipoteichoic acids, and iminosugar conjugates, and examines their antibiofilm, anti-adhesion, and antivirulence activities against clinically relevant bacterial pathogens, including Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterococcus faecalis, as well as fungal pathogens, particularly Candida species. The criteria used to distinguish low-molecular-mass biosurfactants from high-molecular-mass bioemulsifiers and surface-active cell-wall polymers are stated explicitly, and reported activities are interpreted against the strain, extraction, purification, and assay variables that make quantitative comparison between studies difficult. Mechanistic evidence from gene expression analyses, quorum-sensing interference, molecular docking, and surface-coating experiments on catheters, voice prostheses, and implant-grade materials is organized by biological target rather than by individual study, separating reproducible mechanisms from those inferred from single observations. The review further covers biosurfactant-mediated synthesis of metallic nanoparticles with enhanced antimicrobial stability, food-preservation applications in meat, juice, and egg matrices, and combinations with antibiotics and antifungals. Evidence remains almost entirely in vitro: one intravaginal murine study and four food-matrix trials constitute the whole body of work performed outside laboratory culture, and no clinical data exist. Low and rarely reported yields, protocol-dependent purification, undetermined structure-activity relationships, unassigned biosynthetic gene clusters, and the absence of standardized characterization protocols are identified as the principal barriers to translation, alongside research priorities in genome mining, multi-omics, fermentation and downstream process development, standardized bioassay, and CRISPR-based metabolic engineering of LAB chassis.