Study On The Optimal Extraction Process And The Activity Of Cordyceps Cicadae Polysaccharide

Cordyceps cicadae was used as chinese traditional medcine for a long time and it was recorded 800 years earlier than Cordyceps sinensis.A variety of medicinal ingredients such as Mannitol,Polysaccharide,Amino acid,Cordycepin,Adenosine was included in Cordyceps cicadae.However,the resource of feral Cordyceps cicadae is very rare which limite theextensive use of it.This paper mainly foucs on the optimization of Cordyceps cicadae fermentation conditions,the analysis of various medicinal ingredients in Cordycepscicadae,the optimization of extraction conditions of Cordyceps cicadae polysaccharide,the effect of Cordyceps cicadae polysaccharide on Escherichia coli and Staphylococcusaureus.The main results are as follows: 1.Basing on the single factor experiment,we studied on the factors of carbon sources,nitrogen sources,inorganic salts and liquid volume in the liquid fermentation of Cordyceps cicadae mycelia.Finally we determined that the optimal condition was 3% sucrose,1% yeast extraction,0.15% potassium dihydrogen phosphate,0.07% magnesium sulfate,100/250 mL medium volume.The results are verified by shake flask and fermentation tank.2.Basing on the single factor experiment,the orthogonal experiment and the response surface optimization design,we studied on the factors of the ratio of material to liquid,ultrasonic time,pre soaking time and water extraction time in extracting Cordyceps cicadae polysaccharide from the fermentation of Cordyceps cicadae mycelium.Finally we concluded that the optimum conditions ofCordyceps cicadae polysaccharide extraction was the ratio of solid to liquid 1 to 22,pre soaking time 6h,ultrasonic time 43 min,extraction time 2.2h.3.The content of polysaccharide was purified by phenol sulfuric acid method for the determination of adenosine 2.11%,0.171% high performance liquid chromatography,the cordycepin was undetected.4.Cordyceps cicadae polysaccharide had no inhibitory effect on Aspergillus niger,had better antibacterial effect on Escherichia coli and Staphylococcus aureus,the minimum inhibitory concentration was 10mg/mL.5.Scanning electron microscopic observation showed that Cordyceps cicadae polysaccharide can destroy the structure of the bacterial,and the extent of the damage was related to the concentration of Cordyceps cicadae polysaccharide.The result indicated that Cordyceps cicadae polysaccharide had the effect on the damage of the bacterial structure.6.Extracting bacterial genomic DNA from the bacterial which was treated under the Cordyceps cicadae polysaccharide and conducted to agarose gel electrophoresis.With the increase of the concentration of Cordyceps cicadae polysaccharide,gel electrophoresis bands of DNA were more and more shallow,but did not appear to diffuse,which showed that Cordyceps cicadae polysaccharide did not have the effect on the diffusion of the bacterial genomic DNA.As a result,the antibacterial mechanism of Cordyceps cicadae polysaccharide probably was the damage effect on the bacterial structure.