Study On Preparation Technology Of Selenium Polysaccharide Of Lentinula Edodes

Selenium polysaccharide is a safe,effective and healthy selenium nutrient source,which maintains the basic configuration and physiological functions of the polysaccharide and improves the bioavailability of selenium.In this paper,the ability of biosynthesis of selenium from mycelium of Lentinus edodes was used to prepare selenium polysaccharides from Selenium edodes by adding sodium selenite solution during the fermentation of Lentinus edodes.And optimize its process,use Box-Benhnken experimental design and response surface analysis method to obtain the optimum parameters of fermentation conditions.The Sevage method was used to remove the protein and the intracellular crude selenide polysaccharide was purified by column chromatography using Cellulose DE-52 cellulose column to obtain the intracellular selenide polysaccharide product.The value of total selenium,organic selenium and inorganic selenium in intracellular Selenium Selenide products was determined by means of UV and IR spectra,and the prepared selenium polysaccharides were identified for their antioxidant activity.The main results are as follows:1.Selenium-resistant selenium experiments and experimental results were analyzed,Qiuzai 7 was selected as the test strain for enriching selenium polysaccharide by liquid fermentation.The domesticated selenium concentration was 1 mg/L.2.The result showed Na₂SeO₃ solution was sterilized by filtration,the incubation duration was 11 d,when the biomass was used as the evaluation index,the culture medium was pH3.75,6 mg/L Na₂SeO₃ was added to the fermentation broth at 6.62 days,the intracelluar polysaccharide was the highest,reaching1.3964g/100mL;when the intracelluar polysaccharide was used as the evaluation index,the culture medium was pH4.16,7.97 mg/L Na₂SeO₃ was added to the fermentation broth at 6.75 days,the intracelluar polysaccharide was the highest,reaching 121.83mg/100mL;when the extracelluar polysaccharide was used as the evaluation index,the culture medium pH was4.01,6.68 mg/L Na₂SeO₃ was added to the fermentation broth at 7.98 d,the biomass dry weight was the highest,reaching 673.7mg/100mL.3.After the removal of protein by Sevage method,Selenium Polysaccharide of L.edodes Cellulose DE-52 cellulose column purification,resulting in three polysaccharide components,P3A、P3B、P3C no other polysaccharides,nucleic acids or proteins.4.The results of infrared spectroscopy showed that 877.99cm^-11 in P3B is a characteristic peak of pyranosyl bonds andβ-glycosidic bonds,indicating that selenium is involved in the synthesis of polysaccharides,resulting in a change in the structure of polysaccharides.P3,P3A,P3B,and P3C all have obvious peaks between 400⁶00 cm-1,and may have Se=O or Se-H structures.5.The process of enriching selenium increased the content of organic selenium.The organic selenization rate of P3A was the best,and the organic selenium content was46.75μg/g.The order of scavenging DPPH free radicals of lentinan from strong to weak was:P3C>P3A>P3B>P3>P1>P4>P2.The enrichment of selenium not only increased the yield of lentinan,but also increased its antioxidant activity.The viscosity-average molecular weights of P3A,P3B,and P3C are all within a range of effective physiological and biological activities.Three components of selenium polysaccharides P3A,P3B and P3C were obtained through fermentation,and organic selenium content was detected in all three components.Selenium enrichment process not only increased the yield of lentinan,but also converted inorganic selenium.It truly exerts biological activity on organic selenium and also enhances its antioxidant activity.