Extracellular polymeric substances (EPS) of microbial origin have gained significant attention due to their low toxicity, high biodegradability, and diverse functional properties compared to synthetic alternatives. They serve as emulsifiers, stabilizers, thickeners, texturizers, flocculants, and gelling agents. This study aims to evaluate EPS production by lactic acid bacteria (LAB), particularly strains with Generally Recognized as Safe (GRAS) status, including members of the Lactobacillus group. Eight LAB isolates Lactobacillus plantarum GDS82, Limosilactobacillus fermentum GD29, Lactobacillus plantarum GD26, Lactobacillus helveticus GD10, Lactiplantibacillus plantarum GD14, Limosilactobacillus fermentum GD24, Lactobacillus helveticus GD2SC, and Limosilactobacillus fermentum GD13—were screened for EPS production. Among these, L. fermentum GD29 exhibited the highest yield, producing up to 17 g/L of EPS with elevated carbohydrate, protein, and reducing sugar content. FT-IR analysis identified various functional groups, including alcohols, aldehydes, alkenes, sulfonates, vinyl ethers, and phenols, while GC–MS analysis revealed metabolites such as esters, aldehydes, ketones, and terpenes associated with food and industrial applications. The EPS demonstrated notable antibacterial activity, with inhibition zones against Escherichia coli (14 mm) and Salmonella spp. (12 mm), and also showed activity against Vibrio cholerae and Staphylococcus aureus . Additionally, L. plantarum GD26 exhibited an inhibition zone of 11 mm against E. coli . The findings indicate that EPS derived from Limosilactobacillus fermentum GD29 and Lactobacillus plantarum GD26 possess significant antibacterial activity against foodborne pathogens. In particular, EPS from L. fermentum GD29 demonstrates strong potential as a multifunctional, LAB-derived biopolymer with promising applications in food and industrial sectors. • High EPS yield: Limosilactobacillus fermentum GD29 produced up to 17 g/L of exopolysaccharides (EPS) under optimized conditions. • Comprehensive structural insights: FT-IR and GC–MS analyses revealed diverse functional groups and bioactive metabolites, including alcohols, aldehydes, esters, and terpenes. • Antibacterial activity: EPS exhibited strong inhibitory effects against key foodborne pathogens such as E. coli , Salmonella , Vibrio cholerae , and Staphylococcus aureus . • Industrial relevance: The multifunctional EPS shows potential as a natural emulsifier, stabilizer, and flavor-enhancing agent for food and biotechnological applications. • GRAS-based biopolymer: Demonstrates the potential of safe, LAB-derived EPS as a sustainable alternative to synthetic additives in the food and pharmaceutical industries.
Radhamanalan et al. (Fri,) studied this question.