Research On The Process Of Mushroom Fermentation And Its Polysaccharide Extraction

Lentinin, isolated from Lentinula edodes, has demonstrated broad applicationprospect for its unique activities such as inhibition of tumor growth, reduction ofblood lipid, immunomodulation and antiinfection. This paper focuses on studying theconditions of submerged fermentation besides the isolation and extraction ofpolysaccharides in fermentation broth. The optimum conditions were determined asfollows:(1) B08was selected as the best mushroom strain from25strains includingS600,9015, L9608, L9601, L26, B02, B03, B05, B06, B08, K98,808,856,868,087,931,939,939-1by determinating the growth rate of the mycelium, the biomass underthe submerged fermentation and the polysaccharide content in broth with the resultsas12.47mm/d,11.68g/L,1.03g/L respectively.(2) The components of the strain B08submerged fermentation medium wereoptimized by singel factor test.The optimal carbon source, nitrogen source, inorganicsalts and pH value were Glucose, Peptone, Magnesium sulfate, and6respectively.Based on these results, the optimal culture medium were obtained as Glucose2.0%,Peptone1.5%, Magnesium sulfate0.07%and pH7.0by the thogonal test. The yieldof polysaccharide reached1.58g/L under the chosen condition.(3) The cultivation conditions were optimized as temperature as26℃, the liquidvolume as100mL in250mL flask and the rotating speed as160转/分é'Ÿrespectively.(4) The factors in Sevage method to remove the protein in the broth wereinvestigated. The single factor test were conducted first. On that basis, the conditionswere optimized by the orthogonal test as follows, the volume ratio of sevage regent tofermentation broth1:1, the volume ratio of chloroform to butanol5:1, the shakingduration25min, and conduction the protein removal procedure4times.(5) The conditions of extraction Polysaccharides from the fermentation broth viaalcohol precipetition were also studied. By conducting the singel factor test, theamount of ethanol added, the time and pH value of alcohol precipetition were investigated. On the basis of which, the orthogonal test was subsequently performedto determine the optimal conditions as follows, the ethanol added as3times volumeof fermentation broth, the time and pH value of alcohol precipetition as24h and7.0respectively.