Study On Extraction Process And Antimicrobial Activity Of Polysaccharide From Chinese

Objective To optimize the extraction process of yam polysaccharide and itsseparation and purification. To analyze the composition and structure of eachcomponent from yam polysaccharide. To investigate the inhibition of yampolysaccharide on five pathogens in vitro.Method Hot water and ultrasonic were used to extract yam polysacchariderespectively. The extraction yield was index, optimized extraction by using centralcomposite design-response surface methodology based on the single factor, todetermine the optimum extraction method of yam polysaccharide. The removing ratefor protein and loss rate for polysaccharide were indices to compare Sevage and TCAmethod for removing protein. Hydrogen peroxide was used to decolorize and dialysisto remove small molecule impurities. CTAB was used to separate yam polysaccharide,the components were purified by Sephadex G-100. The molecular weight wasdetermined by HPGPC. IR was used to analysis structure. Monosaccharidecomposition was determined by GC. NMR was used to determine the anomericcarbon configuration. To investigate the inhibitory effect of polysaccharide by diskdiffusion method.Results Hot water extraction method was determined to extract polysaccharidefrom yam, the optimum condition were extraction time2.53h, extracting temperature90℃and ratio of water to raw material19. The extraction yield was3.37%andcontent was38.8%under the optimization conditions. Sevage method was used toremove protein and repeated four times, the removing rate for protein was81.7%andloss rate for polysaccharide was17.2%. Obtained acidity polysaccharide CYP-1andneutral polysaccharide CYP-2after separation by CTAB and purification by SephadexG-100. CYP-1and CYP-2were water soluble, non-starch polysaccharide with noproteins and amino acids. The molecular weight were25171Da and47786Da. Twopolysaccharides had characteristic absorption peaks by IR. GC analysis showed that CYP-1was made up of rhamnose, arabinose, mannose, glucose, and galactose, CYP-2was made of rhamnose, arabinose, glucose, galactose. Two polysaccharides wereβ-configuration, and CYP-2could contain α structure. Antibacterial experimentsshowed that two polysaccharides had good antibacterial activity, best againststaphylococcus aureus followed by bacillus subtilis, candida albicans, escherichiacoli,the effect was not obvious of salmonella enteritidis.Conclusion Hot water was determined the experimental method of yampolysaccharide. Obtained two water soluble and non-starch polysaccharides byisolation and purification with different molecular weights and structures.Antibacterial activity in vitro showed that yam polysaccharide have differentinhibitory effect on staphylococcus aureus, bacillus subtilis, candida albicans andescherichia coli.