类芽孢杆菌ZC01胞外多糖的制备和生物活性的研究

Abstract硕士论文AbstractIn recent years,microorganisms extracellular polysaccharide,as a kind of newfermentation products,because of its unique physical and chemical properties,such aseasily available,relatively low cost,is widely applied in various industries.A newstrain ZCOl was isolated from a soil sample from Henan farmland in our laboratory.The bacteria could use inorganic medium to produce extracellular polysaccharide.According to preliminary identification and 16S rDNA homology analysis,thebacteria was identified as the genus Paenibacillus (Paenibacillus sp.ZC01).By ethanol precipitation,the fermented liquid was added more than 2 times ofethanol,the metabolic product was precipitated out and dried,the crude products ofthe extracellular polysaccharide would be obtained.The fermentation conditions wereoptimized through single factor,the best fermentation conditions to produce moreExtracellular polysaccharide was studied in this paper.Its media component wasSoluble starch 30 g/L,peptone 4 g/L,disodium hydrogen phosphate 1.2 g/L,potassium dihydrogen phosphate 0.6 g/L,calcium chloride 0.1 g/L,magnesiumchloride 0.3 gL,ferrous sulfate,0.0125 g/L,manganese sulfate,0.003 g/L,zincchloride 0.01 g/L,1 L water,pH8.0,28 C.the maximum yield could reach 15.5 g/L.The chemical composition of exopolysaccharide are moisture 8.65%,protein16.24%,total sugar 64.01%,ash 10.9%.Through separation and purification,gaschromatography,infrared spectrum,nuclear magnetic resonance (NMR)and sugarresidue determination,the extracellular polysaccharide was found is a kind ofheteropolysaccharide composed of four kinds of monosaccharides.Four kinds ofmonosaccharide composition were glucose,mannose,galactose,rhamnose,theirmolar ratio was 1.2:1.2:0.7:1.And the exopolysaccharide is found to contain a certainamount of uronic acid,is a kind of acidic heteropolysaccharide.We studiedmoisture-retention capacities and antioxidant of the exopolysaccharide.We found thatthe polysaccharide has moisture-absorption and -retention capacities and the wellcapable of scavenging free radicals compared with hyaluronic acid.Therefore,All theresults from this paper have shown that the polysaccharide has a widely applicationprospect and could be used to in cosmetics.Keywords:Paenibacillus sp.ZC01,polysaccharide,antioxidant,Moistureabsorption,Moisture retention,separation and purification