Exopolysaccharide in Lactobacillus Rhamnosus Pn04 After Co-Culture with Leuconostoc mesenteroides Vtcc-B-643

Exopolysaccharides (EPS) from lactic acid bacteria (LAB) have many applications in food industry, and pharmaceutical field. To improve EPS production in Lactobacillus rhamnosus PN04 and Leuconostoc mesenteroides VTCC-B-643, these bacteria were co-cultured together. There were shape changes in Lactobacillus rhamnosus into curved rod. Their EPS were estimated after co-cultured. After ethanol precipitation method, the colorimetric method were done using phenol-sulfuric acid assay, the EPS from L. rhamnosus PN04 increased from 2.446 mg/l to 4.228 mg/l while Leuconostoc mesenteroides increased from 3.217 mg/l to 4.712 mg/l. By SDS-PAGE analysis in both straight and curved Lactobacillus rhamnosus, there were the expressed proteins with the estimated molecular weight of 14, 60, 66 kDa while the curved Lactobacillus rhamnosus showed another proteins with molecular weight of 14, 20, 31, 45, 60, 66, 95 kDa. The results suggested that there were the interaction between two these strains. This is the first report showed there were differences in EPS production and protein expression after co-culture of Lactobacillus rhamnosus PN04 and Leuconostoc mesenteroides VTCC-B-643.