Optimization Of Fermentation Conditions And Extracting Methods Of Polysaccharides From Lepista Sordida

Screening the optimum conditions of Lepista sordida liquid fermentation by single factor experiment,the optimal combination: temperature 28 ?,culture time 7 days,sucrose,yeast extract powder,pH 7.0.On this basis,orthogonal optimization design was used to optimize Lepista sordida culture conditions,the optimal combination: sucrose 30 g,yeast 6 g,monopotassium phosphate 0.1 g,magnesium sulfate 1 g.In this study,four kinds of bioactive polysaccharides extracted in hot water,alkaline solution,multiplex-enzyme,ultrasonic-assisted were compared and analyzed by infrared spectroscopy and many other methods to assess the effect of different extraction methods on the physicochemical properties of the polysaccharide,and selected the extraction process by polysaccharides characteristics.The results show that,The infrared spectrum characteristic peaks of four polysaccharides are similar,but the peaks among 1022~1153 cm-1 showed polysaccharides extracted in alkaline solution has furanose ring,and the other three have pyranose ring.Three kinds of polysaccharide solution expressed a high DPPH radicals scavenging rate,but poor effect result in polysaccharide extracted in alkaline solution.Little difference occurred in hydroxy radicals scavenging rate of polysaccharides extracted from four different processes.In conclusion,polysaccharides extracted with multiplex-enzyme showed good extraction efficiency,low protein content,namely good purity,and powerful anti-oxidant activity,so it was the best one in these four methods.Screening the optimum conditions of polysaccharide extraction of Lepista sordida,The optimum extraction temperature 90 ?,extraction duration 3h,ratio of water to material 70:1.BBD design was used to screen the optimum conditions of production for polysaccharides from lepista sordida,and the optimal extraction conditions: ratio of water to material 72.08:1,temperature 92.85 ?,time 2.86 h.Under these conditions,polysaccharide extraction rate predictive value is 16.54%,the actual extraction rate is 16.55%,consistent with the predicted values.