Research On Key Techniques Of Producing Lentinus Javanicus Polysaccharide By The Method Of Liquid Fermentation

Edible fungi are not only rich in nutrients and delicious,but also possess medical and health care efficacy.They usually show anti-tumor,anti-oxidation, anti-senility,anti-virus and anti-radiation activities,decrease blood sugar,blood lipid and blood pressure.Besides,they could improve immunity of human.A number of experiments had proved that the main functional component in edible fungi is polysacchafide.Being a member of the family of edible fungi,the polysaccharide of Lentinus javanicus probably has significant value of development and application. Nevertheless,researches on Lentinusjavanicus are never reported both at home and abroad.Mother culture medium,medium for growing liquid seeds,liquid fermentation medium and fermentation conditions for Lentinus javanicus were studied preliminarily.In the study of Mother culture medium for Lentinus javanicus,mediums that most adapt to Lentinula javanicus were screened from 10 kinds of potato semi-synthetic mediums by the method of single factor experiment with randomized block design.Mediums on which the mycelia could grow well and fast were expected.The results showed that the best mother culture mediums are medium A8: potato 20%,glucose 2%,wheat bran 2%,maize meal 2%,peptone 0.2%, MgSO₄7H₂O 0.05%,KH₂PO₄ 0.1%,V_B10.001%,agar2%,and medium A₁₀:potato 20%,glucose 2%,wheat bran 5%,yeast extract 0.25%,peptone 0.1%,MgSO₄7H₂O 0.05%,KH₂PO₄ 0.1%,agar 2%.When studied medium for growing liquid seeds,a relatively better medium for growing liquid seeds of Lentinula javanicus was selected from 6 kinds of liquid medium also by the method of single factor experiment with randomized block design,considering the indexes as followings:the degree of medium's clarity,the shape of mycelial pellets,the number of mycelial pellets and the dry weight of mycelia.Then,through orthogonal experiments(L₉3⁴),the concentrations of carbon source and nitrogen source were optimized on the base of primary screening.The results showed that,the components of liquid medium which most adapt to Lentinulajavanicus for growing liquid seeds were:maize meal 4%,sucrose 2.5%, yeast extracts 0.3%,KH₂PO₄0.1%,MgSO₄7H₂O 0.05%,V_B10.005%,pH5.25.In order to improve the intracellular polysaccharide yield of Lentinula javanicus,the liquid fermentation medium was studied.The effect of carbon sources, nitrogen sources and their concentrations were studied by single factor experiments. Then the optimal concentrations of KH₂PO₄,MgSO₄7H₂O and V_B1were optimized by orthogonal experiments(L₉3⁴).The results showed that,the best liquid fermentation medium for the mycelia of Lentinulajavanicus to product intracellular polysaccharide is as follow,glucose 2%,amidulin 2.5%,yeast extract 0.1%, KH₂PO₄ 0.1%,MgSO₄7H₂O 0.05%and V_B10.001%.Finally,fermentation conditions were studied.The effect of pH value,medium volume in 250 ml conical flask,rotation speed and days of culture were studied by single factor experiments.Then inoculation volume,culture temperature and the number of glass beads were optimized by orthogonal experiments(L₉3⁴).The results showed that,the best liquid fermentation condition is pH4～5,50ml～100ml fermentation medium in 250ml conical flask,130r/min,9 culture days,10% inoculation volume,28℃,10 glass beads.When the mycelia of Lentinula javanicus ware cultured in the optimized liquid fermentation medium under this condition,the yield of intracellular polysaccharide was up to 869.46μg/ml.