Biosurfactants from lactic acid bacteria: A critical review on production, extraction, structural characterization and food application

Biosurfactants are structurally diverse classes of amphiphilic molecules derived from microorganisms. They have various properties such as surface, emulsification, antibacterial, anti-adhesive, anti-biofilm, antioxidant activity that can be used in many industrial fields. The interest in these molecules compared to their synthetic counterparts is due to their biodegradability, low toxicity, structural diversity, and stability over a wide range of pH, temperature, and salinity. Among biosurfactants, those derived from lactic acid bacteria (LAB) attracted attention nowadays due to the GRAS (Generally recognized as safe) status of these microorganisms. Biosurfactants production by LAB strains has been documented in several investigations, and they deal with the functionality and chemical nature of biosurfactants. LAB biosurfactants were mainly a complex mixture of proteinaceous compounds, glycolipids, glycoproteins, or glycolipopeptides. There are only a few studies reporting on the elucidation of the structure of LAB biosurfactants. Generally, biosurfactants' production process includes several unit operations starting from screening methods to the characterization of the biosurfactant compound. This review highlights the different techniques used in the screening of biosurfactants production by LAB, their extraction and purification processes, and their structural characterization and application in the food industry. • LAB are unique producers of biosurfactants with industrial applications. • They possess properties like surface, emulsifying, antiadhesive, antibiofilm, and antioxidant activities. • Biosurfactants from LAB are a complex mixture of several compounds. • The complexity of LAB-biosurfactants hampers their structural characterization. • Structure elucidation of LAB-biosurfactants was done using several techniques.