Study On Fermentation Conditions And Extraction Process Of Polysaccharide From Liquid Fermentation By Fomes Officinalis Ames

The process of liquid fermentation by Fomes offcinalis Ames of Uyghur Traditional Medical to produce polysaccharide were investigated under laboratory conditions. The main research contents and results are as follows:(1) Wild strains of Fomes offcinalis Ames were separated, purified and preserved using the solid plate and slant of rich PDA. At the same time, the culture temperature and time were investigated preliminarily. The results showed that Fomes offcinalis Ames can grow normally at the temperature range of 15-30℃and growth tend to stop after cultivated 8-10 days.(2) In order to obtain the suitable nutrition conditions of seed media, single factor and orthogonal test were carried out for the best choices of sort and concentration of carbon source, nitrogen source, metallic ion and growth factor. The optimal content of seed media obtained according to the yield of biomass were as follows:glucose 3%, peptone 1.5%, KH2PO40.3%, MgSO4·7H2O 0.1%, VB1 0.1 mg/mL. The results showed that the yield of dry mass could reach amount 1.2 mg/mL with the optimized seed media and cultivated 12d.(3) Fermentation media was chose and components of fermentation were optimized by single factor and orthogonal test. The results showed that, cultivated 12d, the yield of dry mass and extracellular polysaccharide could reach amount 1.31 mg/mL and 1.5 mg/mL respectively with the optimized fermentation media that glucose 1%, malt extract 0.3%, peptone 0.75%, yeast extract powder 0.5%.(4) The fermentation conditions of initial pH, broth content, shaking speed and cultivate method etc. were further explored on the basis of optimization results of medium by single factor and orthogonal test. The results showed that under the optimal culture conditions of YM medium, initial pH5.0, broth content 75 mL/500mL flask,20℃, shaking speed 180 r/min and batch culture in dark place, amount 1.36 mg/mL of mycelia biomass and 1.60 mg/mL extracellular polysaccharide yield could be obtained respectively after 12 days in submerged cultures.(5) For confirm the best extraction technology of polysaccharides of Fomes offcinalis Ames as the aim production of fermentation, we contrastively studied the extraction of hot water, dilute acid, dilute alkali and ultrasonic and ascertained finally that the best extraction process was ultrasonic-assisted hot water extraction. In order to obtaining the suitable extraction process, single factor and orthogonal test were carried out and recovery rate was the only target. The results showed that 66.5mg intracellular polysaccharide can be extracted every gram dry mycelia under the conditions of ultrasonic power 90W, ultrasonic time 15min, extract temperature 90℃, ratio between dry mycelia and water 1:20, extract time 3 hours and maximize extracellular polysaccharide recovery rate can be achieve 92.1% under the conditions of ethanol concentration 60%, precipitate temperature 4℃, solution pH7.0, precipitate time 24 hours.