Immunomodulatory effects of exopolysaccharides produced by Bacillus licheniformis and Leuconostoc mesenteroides isolated from Korean kimchi

[Display omitted] •We isolated and characterized two EPS-producing bacterial strains from kimchi.•Both EPS were composed of glucose, fucose, mannose, galactose, and arabinose.•EPS yield was highest at an initial medium pH of 7.0.•Both EPS exhibited anti-inflammatory effects in LPS-stimulated RAW264.7 cells. The immunomodulatory properties of exopolysaccharides (EPS), major components of bacterial biofilm, are not fully understood. Here, we examined the immunomodulatory potential of EPS derived from Bacillus licheniformis BioE-BL11 and Leuconostoc mesenteroides BioE-LMD18, isolated from Korean fermented kimchi. EPS from BioE-BL11 was composed of mannose (12.4%), galactose (1.82%), glucose (48.5%), fucose (37.1%), and arabinose (0.17%), and that from BioE-LMD18 was composed of mannose (8.71%), arabinose (0.07%), galactose (1.22%), glucose (79.8%), and fucose (10.21%). The highest EPS yield were obtained by incubation at 37 °C for 3 days with an initial pH of 7.0, without optimizing other conditions. The EPS from BioE-BL11 and BioE-LMD18 significantly inhibited secretion of the pro-inflammatory cytokine IL-6 in lipopolysaccharide-stimulated RAW264.7 mouse macrophage by 40.7% and 32.1%, respectively, enhanced secretion of the anti-inflammatory cytokine IL-10 in a dose-dependent manner, suggesting that EPS produced by these strains may be useful functional ingredients for the cosmetics, food, and pharmaceuticals industries.