Study on Structure,Antioxidant and Immune Activity of Capsular Polysaccharides from Lactobacillus Fermentum GBJ
The capsular polysaccharides(CPS)of Lactobacillus fermentum GBJ were extracted with enzymes and the primary structure,antioxidant activity in vitro and immune activities of the CPS were investigated.The results showed that the CPS production of L.fermentum GBJ was 124.37 mg·L-1,with neutral sugar content of 92.54%,protein content of 3.06%,sulfate group content of 1.04%,and no uronic acid.The monosaccharide composition showed that CPS was mainly composed of galactose and glucose with molar ratio of 3.64∶1.00.Infrared analysis showed that CPS had characteristic absorption peak of polysaccharide.In addition,CPS showed higher DPPH,ABTS+ and hydroxyl radical scavenging abilities in vitro.At the same time,appropriate concentration of CPS could significantly improve the neutral red phagocytosis and the secretion levels of cytokines(IL-1β,IL-6 and IL-10)in RAW264.7 cells(P<0.05),which indicated that CPS had a good immunomodulatory effect.It could provide theoretical basis for the future development and application of lactic acid bacteria CPS.