| Pellinus igniarius a precious medicinal fungus,was recorded with the high reputation and with extremely high medicinal value by the ancients in Shennong’s Herbal Classic as early as 2000 years ago.The medicinal fungus P.igniarius contains a variety of bioactive components with medicinal value,such as polysaccharide compounds,flavonoids and so on.Flavonoids are one of the main medicinal active substances of P.igniarius.Flavonoids has various medicinal value,such as inhibit tumor growth,remove reactive oxygen,reduce blood sugar,anti-inflammatory antiviral and so forth.Therefore,it is of great significance to improve the content of flavonoids for high quality P.igniarius.This thesis studied the effect of exogenous inducers such as acetic acid on the content of P.igniarius flavonoids,optimized conditions of the induction treatment,and analyzed the changes in fingerprints of P.igniarius flavonoids under the treatment of exogenous inducers.The main results are as follows:In order to improve the efficiency of liquid fermentation of P.igniarius,the influence of carbon sources,nitrogen sources and C/N of the culture medium on the flavonoid content of P.igniarius mycelium were investigated.It was found that when the carbon source was maltose,the mycelial biomass and flavonoid content of P.igniarius was 0.683 g and 39.89 mg/g,respectively.By using yeast extract as nitrogen source,the mycelial biomass and flavonoid content of P.igniarius was 0.632 g and 39.18 mg/g,respectively.When C/N is 40:1,flavonoids content of P.igniarius was 65.16 mg/g.Based on these results,the effect of acetic acid and citric acid on the content of flavonoids in P.igniarius mycelium was explored.It was found that the mycelial biomass and flavonoid content increased by 14% and 23% respectively in 10 m M acetic acid treated group,compared with the control group.By Treating with acetic acid for 72 h,the mycelial biomass and flavonoid content increased by 4.2% and 24.15% respectively,compared with the control group.The mycelial biomass and flavonoid content increased by 10.6% and 29.1% respectively in 3 m M citric acid treated group,compared with the control group.By Treating with citric acid for 48 h,the mycelial biomass and flavonoid content increased by 8.9% and 22.4% respectively,compared with the control group.The results indicated that biomass and the flavonoids content in the mycelium of P.igniarius can be increased by both acetic acid and citric acid treatment.Then,optimal treatment of concentration and time about acetic acid and citric acid were optimized by surface response method(RSM).The result of optimal conditions of acetic acid treatment is as follow: 9.50 m M acetic acid treated for 85.56 h.The result of optimal conditions of citric acid treatment is as follow: 2.77 m M citric acid treated for 69.74 h.According to these results,the effects of different concentrations of acetic acid,citric acid and salicylic acid on the content of flavonoids in the fruiting body of P.igniarius were investigated.It was found that the content of flavonoids increased by 81.71% in 20 m M acetic acid treated group,compared with the control group.The content of flavonoids increased by 49.9% in5 m M citric acid treated group,compared with the control group.The content of flavonoids increased by 35% in 400 μM salicylic acid treated group,compared with the control group.These results indicated that appropriate concentration of acetic acid,citric acid and salicylic acid could increase the content of flavonoids in the fruiting body of P.igniarius.Base on the above results,the fingerprints of flavonoids in the mycelium and fruiting bodies were analyzed by using HPLC.By treated with 10 m M acetic acid,the contents of isoquercitrin,rutin,narcissoside,kaempferol-3-rutinoside,quercetin,and sakuranetin were increased by 68.6%,75%,65%,73%,57%,87% respectively,compared with the control group.By treated with 3 m M citric acid,the contents of isoquercitrin,rutin,narcissoside,kaempferol-3-rutin,quercetin,and sakuranetin were increased by 89.4%,37%,63%,and 152%,42%,14% respectively,compared with the control group.Furthermore,the flavonoid fingerprints of P.igniarius fruiting bodies were also analyzed by using HPLC.It was found that the treatment of acetic acid,citric acid and salicylic acid could significantly increase the content of isoquercitrin,rutin,narcissoside and kaempferol-3-O-rutin.However,quercetin and sakuranetin were not detected in the collected fruiting bodies of P.igniarius.In summary,this study found that exogenous inducers such as acetic acid and citric acid have a significant inducing effect on the flavonoids content of P.igniarius mycelium.Meanwhile,the optimal treatment conditions of exogenous inducer were showed by surface response method.Furthermore the influence of exogenous inducer on the flavonoid content of P.igniarius fruiting body was explored.Base on these results,changes in the fingerprints of the flavonoids in mycelium and fruiting bodies of P.igniarius are analyzed by using HPLC.The results of this study provide a reference for the production of high-quality P.igniarius with high-active flavonoid. |
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