Functional Characterization of Exopolysaccharides from Probiotic Lactiplantibacillus plantarum BDIM014 Cultivated in a Vegetable-Based Edible Growth Medium

Abstract In the present study, the production of exopolysaccharides (EPS) by lactic acid bacteria (LAB) was optimized through the application of different growth media, followed by evaluating the structural and functional properties of the EPS. An EPS-producing strain of Lactiplantibacillus plantarum BDIM014 was evaluated for its probiotic potential using in vitro tests, including probiotic characterization and safety assessment. Two growth media, MRS and vegetable-based edible media, were optimized for EPS yield, followed by structural characterization and evaluation of biological activities. L. plantarum BDIM014 strain demonstrated tolerance to acidic conditions, bile salts, and high temperatures, and showed no hemolysis. It also exhibited promising adhesion properties, including self-aggregation, coaggregation with Escherichia coli ATCC 11303 and Salmonella Typhi ATCC 13311, and cell surface hydrophobicity in chloroform and n-hexadecane. A comparative growth study revealed higher viable cell counts in edible media compared to MRS. An EPS yield of 2.39 ± 0.21 g/L was observed in edible media versus 0.281 ± 0.04 g/L in MRS after 48 h of incubation. FTIR showed functional groups, while XRD demonstrated an amorphous structure. The LC-ESI-MS analysis suggested the presence of hexose monosaccharides within the polysaccharide structure of EPS, and TGA and DSC revealed good thermal stability of the EPS. The EPS exhibited emulsifying activity toward olive and soybean oil. Furthermore, EPS supplementation promoted LAB growth and increased SCFA production, suggesting its functional prebiotic activity. Overall, the findings suggest that the vegetable-based edible medium can serve as an effective alternative to conventional MRS for scaling up EPS production. It offers a promising way to produce useful microbial EPS sustainably, with potential applications in the food and other bioprocessing industries.