Effects Of Microbial Degradation Of Polysaccharides Produced By Straw On Cell Division And Differentiation

China is a large agricultural production country and rich in crop straw resources.The random disposal and burning of crop straws will lead to the problems of resource waste and environmental pollution.Therefore,the utilization of straw resources is of great significance to China's sustainable development.The investigations were carried out for the separation and purification of polysaccharide from crop straw by microbial fermentation,the several chemical and physical properties of polysaccharides and the application of purified polysaccharides in callus inductivity,giving the following conclusions.?1?The Corn Stalk Polysaccharide?CSP?was obtained from crop straw by microbial fermentation,the centrifugation,deproteinization,alcohol precipitation,washing.And the content of CSP in straw fermentation broth was determined with standard curve method.Then CSP was separated and purified by DEAE-52 cellulose anion exchange chromatography column and sephadex G-100 gel chromatography column,and three kinds of polysaccharides CSP1,CSP2 and CSP3 were obtained under diffenent concentrations of NaCl.And the effect of effect of different loadings on the elution of DEAE-52 cellulose anion exchange chromatography column was carried out.The measured results showed that the content of CSP in straw fermentation broth was 1.884mg/mL.The best separation and purification effects of CSP using DEAE-52 cellulose anion exchange chromatography column were obtained when the loading was 0.2 g.The peak of the elution curve measured by sephadex G-100 gel chromatography column was single and symmetrical,which showed that the separation and purification effects of CSP were improved.The statistics results showed that the recovery rate of polysaccharide in the separation and purification process was 16.3%.?2?The appearance,structure and antioxidant resistance of polysaccharides was evaluated based on Electron Microscopy?SEM?,Fourier Transform Infrared Spectroscopy?FT-IR?and Gas Chromatography?GC?.The results of SEM showed that CSP was irregular granular,CSP1with smooth surface was powdery particles,CSP3 was flake-like,and CSP5 floccules.The results of FT-IR showed that all three polysaccharides were pyranose structures.The results of GC indicated that three polysaccharides were composed of six monosaccharides with different proportions,and the main components of three polysaccharides were arabinose,xylose and galactose.Three polysaccharides had antioxidant resistance,and the antioxidant resistance of CSP5 was greatest.The highest DPPH free radical scavenging rate was 0.6 mg/mL,and the clearance rate reached 84.86%.The concentration of 1.2 mg/mL had the strongest scavenging ability to O₂·-,the clearance rate was 53.64%.The concentration was 1.2 mg/mL,the OH·clearance rate at mL was 64.03%.?3?Purified polysaccharides were used as additives to induce callus growth.Straw polysaccharide had obvious inhibitory effect on the browning of the callus of Taxus chinensis,but the inhibition was weaker than ascorbic acid.The qualitative and simple quantitative analysis of paclitaxel in callus by thin layer chromatography-ultraviolet spectrophotometry showed that the results showed TLC can effectively separate paclitaxel from the callus crude extract,and the standard curve method measures the paclitaxel content per gram of callus to0.165 mg.