Study On Biological Activities And Optimization Of Submerged Culture Conditions For Xylaria Escharoidea

The optimum submerged culture conditions of Xylaria escharoidea were got throughquantities of one-factor-at-a-time experiments,orthogonal experiments.Optimization for extraction of polysaccharide from Xylaria escharoidea mycelia were gotthrough quantities of one-factor-at-a-time experiments,response surface design experiments.Thebest concentration of carbon source,nitrogen source and the regress equation were obtainedthrough analyzing the results by Design-Export software.It was the report on the Xylariaescharoidea antioxidant activity ex vivo.The antioxidant potency of intracellular polysaccharideand exopolysaccharide from Xylaria escharoidea in submerged culture was investigated todetermine the antioxidant activity ex vivo,employing various established in vitro systems,suchas reducing power,superoxide (O2.-),hydroxyl (.OH) and DPPH radical scavenging.Vc was usedas positive controls.The optimum carbon source was soluble starch,the optimum nitrogen source was potatojuice,the optimum inorganic salt was magnesium sulfate5.0-8.0was the suitable pH value scopefor it's growth.Xylaria escharoidea was a middle-temperatue fungus which can grow at thecircumstance of20℃-35℃,but the optimum temperature is25℃-30℃.4days was its optimumfungus age.The optimum medium constitutes for the liquid fermentation of Xylaria escharoideawere：soluble starch2.0%,potato25%,magnesium sulfate0.1%,incubation time9days.The optimum water bath treatment was90℃,the optimum extraction time was3hours,theoptimum weight of mycelium/volume of distilled water was1:30,the optimum extraction timeswas3,the optimum ratio of the volume of concentrated polysaccharide extraction to the volumeof precipitating alcohol was1:3through one-factor-at-a-time method. Response surface designexperiments were adopted to investigate the effects of extraction factors on polysaccharidecontent of Xylaria escharoidea mycelia by Design-Export software. The optimal condition was：water bath treatment(90.58℃)for4.06hours and2times replication,and weight ofmycelium/volume of distilled water=1:25.44.The optimum Ultrasonic extraction of polysaccharide from mycelia were got throughquantities of one-factor-at-a-time experiments and response surface design experiments. Theoptimal condition was Ultrasonic time207.33s,power448.00and weight of mycelia/volume ofdistilled water=1/44.44.It was the first report on the Xylaria escharoidea antioxidant activity ex vivo. The polysaccharide of mycelia, exopolysaccharide had strong antioxidant activity. And theantioxidant activity of polysaccharide was stronger than the exopolysaccharide.This study provided science basis for further research on Xylaria escharoidea andextraction,determination,antioxidant activity of edible and medicinal fungi.