Screening and genome analysis of lactic acid bacteria with high exopolysaccharide production and good probiotic properties

Exopolysaccharide (EPS) is a biological polymer produced by lactic acid bacteria (LAB) with various health-beneficial biological activities, such as hypoglycemic, antioxidant, hypocholesterolemic, and immune-regulatory effects. As a food-grade material, EPS could be used directly in food processing and production. In this study, 48 laboratory-preserved LAB strains were screened for high exopolysaccharide production, the best five of which were M-1 (0.90 g/L), M-2 (0.79 g/L), MY04 (1.15 g/L), M-5 (0.85 g/L) and M-7 (0.75 g/L). The prebiotic properties of these five strains were compared and MY04 had the best overall properties, with good resistance to acid, bile salts, and simulated gastrointestinal fluid, strong antibacterial activity and high intestinal adhesion capacity. Whole genome sequence analysis of virulence factors and drug resistance genes, determined that Lactiplantibacillus plantarum MY04 is safe for human consumption and a promising probiotic candidate for development of novel functional foods.