Study On Liquid Fermentation And Polysaccharide Of Lentinula Edodes

Lentinan has many physiological activities such as antithrombotic,anti-tumor and anti-aging.Nowdays,a large number of researches about the fermentation of Lentinan have been carried out,but yield scantily.Four Lentinula edodes strains,conserved in our lab,were considered as the research objects.Using the average growth rate and polysaccharide production as evaluation index was compared in order to select a high quality strain of L.edodes.And using biomass,polysaccharide production,size and quantity as evaluation index was compared in order to obtain the optimal medium.Additing Tween 80 and Chinese herbal medicines explored the effects of them on the liquid fermentation and intracellular polysaccharide?IPS?of L.edodes.Furthermore,the effects of the different time and ways of sugar supplement on the biomass and Intracellular polysaccharide of L.edodes were investigated by a batch-feed fermentation model in shake flasks.It would like to lay the foundation for the liquid fermentation and industrial production of letinous edodes.The primary experimental outcomes are as below:1.After the selection of several medium formula,the liquid seed medium and fermentation medium of L.edodes were determined as C medium?g/L?:glucose 10,yeast extract 20,corn flour 15,V_B1 0.02,MgSO₄ 0.15,KH₂PO₄ 0.3.2.With adding Tween 80,the outputs of biomass and IPS during the L.edodes fermentation increased by 22.19%and 20.85%,respectively,while the reducing sugar content was decreased.It was also shown that additing Tween 80 could protect the intact of pellets from breaking down.The effects of Tween 80 on the main structure of IPS were no obvious,and the IPS was displayed similar infrared spectrum,as was indicated by the infrared spectrum analysis.With adding Tween 80,the viscosity molecular weight of Lentinan reduced,while the antioxidant activity of IPS increased.3.with the exception of medium of Scutellaria baicalensis with 1%,the strain of L.edodes could grow on the 1%concentration of Chinese herbal medicines?Radix liquiritiae?Astragalus membranaceus?Lycium chinensis?Coix seeds?medium.With the respective addition of Radix liquiritiae,Coix seeds and Lycium chinensis,they could improve the biomass of Lentinula edodes and the yield of intracellular polysaccharide.When Astragalus membranaceus added,the biomass decreased while the yield of intracellular polysaccharide increased.Different Chinese herbs have different effects on viscosity average molecular weight of lentinan.Viscosity average molecular weight of Lentinan with the medium adding Scutellaria baicalensis was similar to compare group,but it highest with adding Coix seeds.The effects of Lycium chinensis,Radix liquiritiae and Astragalus membranaceus on the main structure of IPS were no obvious,and the IPS were revealed similar infrared spectrum,as was indicated by the infrared spectrum analysis.However,the infrared chart of polysaccharide with medium adding Coix seeds was no found?-glycosidic linkage.The infrared spectra also indicate that the polysaccharide with medium adding Scutellaria baicalensis was neither?-glycosidic linkage nor?-glucose-the pyran ring.It revealed some distinction in the scavenging capacity of DPPH radicals of IPS with and without the addition of Chinese herbal medicine.4.The results showed that feeding glucose could enhanced the yield of mycelia and intracellular polysaccharide in liquid fermentation of L.edodes.Respective feeding glucose?0.25%?at 6 d and 9 d could greatly stimulate the biomass and intracellular polysaccharide production.Under these conditions,the outputs of biomass and intracellular polysaccharide during the batch-feed fermentation of L.edodes increased by21.79%,34.29%,respectively.