Study On The Structure Identification And Biological Activity Of Microbial Degradation Of Corn Stalk Polysaccharide

China makes a lot of corn stalks each year,most corn stalks are treated as waste,which not only makes resources waste,but also the environment is polluted.Corn stalks have good biotransformation prospects and can be used for various purposes to achieve effective utilization of resources.In this study,corn stalk was used as the substrate,the 7#bacteria was not added as the blank group,and the 7#bacteria group was added as the experimental group.The experimental group polysaccharide P₁,and the basic structures of P₀ and P₁ were analyzed and compared,and the two biological activities of antioxidant and hypoglycemic were studied and explored,and purified polysaccharide P₂ was obtained by three-step purification on Sephadex G-100 column.and perform structural analysis.In order to provide a certain reference for the research on polysaccharides obtained from straw fermentation.The results are as follows:(1)Comparative study on the biological activities(antioxidant and hypoglycemic)of P₀ and P₁:P₀ and P₁ were obtained after centrifugation,rotary evaporation,deproteinization and alcohol precipitation of the corn stalk blank group and the experimental group.Antioxidant activity result dispiay that:Compared with P1,P0has higher DPPH free radical scavenging ability,but the statistical analysis p value was 0.189,p>0.05.the diversity was not significant.P₀ and P₁ had the strongest scavenging ability to hydroxyl radicals when the polysaccharide concentration was0.2 mg/m L and 0.4 mg/m L,respectively,and the scavenging rates reached 39.11%and 32.43%,respectively,but the statistical analysis p value was 0.101,p>0.05.no obviously different.P₀ and P₁ had the strongest scavenging ability when the polysaccharide concentration was 0.8 mg/m L and 0.4 mg/m L,and the scavenging rates were 25.89%and 21.60%,respectively.But statistical analysis p value is 0.541,p>0.05.the difference is not important.When the content was 0.8 mg/m L,the difference in the total reduction ability of Fe³⁺between P₀ and P₁ was the largest(P₁>P₀).The p value of statistical analysis was 0.005,p<0.05.and the difference was significant.P₀ was stronger than P₁ on the removal of ABTS,the statistical analysis p value was 0.001,p<0.05.the difference was significant.The hypoglycemic activity showed that the inhibitory effects of P₀ and P₁ on?-amylase were almost the same,and the statistical analysis p value was close to 0,p<0.05.and the difference was significant.The ability of P₁ to inhibit?-glucosidase was slightly higher than that of P₀,and the p value of statistical analysis was close to 0,and the difference was significant.(2)Structural analysis of corn stalk polysaccharide P₁ relative to P₀:Scanning electron microscopy showed that both P₁ and P₀ had a blocky structure,but P₁ had a smaller particle size than P₀;infrared spectrum analysis showed that both P₁ and P₀had?-glycosidic bonds and?-glycosidic bonds;atomic force microscopy showed that the molecular height of P₁ was smaller than that of P₀;HPLC analysis showed that P₀and P₁ were mainly composed of mannose,ribose,glucuronic acid,galacturonic acid,galactose,xylose,arabinoseThemolarratiosare14.336:1.951:3.630:25.104:24.533:13.575:13.108and12.692:1.957:3.588:21.660:24.459:16.601:15.595,respectively.(3)Structural analysis of P₂:Scanning electron microscope analysis showed that P₂ had a rod-like structure and was a non-starch polysaccharide;infrared spectrum analysis showed that P₂ had typical?-glycosidic bond characteristics and characteristics of pyran ring compounds;AFM analysis showed that compared with For crude polysaccharide,P₂ diameter and molecular chain height range are reduced;HPLC analysis shows that P₂ mainly contains mannose,ribose,galacturonic acid,galactose,xylose,arabinose,and its molar ratio is:0.168:0.055:0.231:0.299:0.079:0.103.