Influence Of Wood Decaying Components,Light And Temperature On The Induction Of Triterpenoids Production In Ganoderma Lucidum Liquid Fermentation

Many fungi obtain main nutrients for their growth by wood decay and it place themselves key players of biogeochemical cycle.Among these fungi some are mushrooms which play indespensible role in our diet structure.Ganoderma lucidum(G.lucidum)is one kind of saprophytic fungi that has been a legendary traditonal Chinese medicine in China and other Southeast countries for thousands of years.Triterpenoids are believed to be the major active components of G.lucidum.Triterpenoids are largely produced in the primordium and fruting body but not from mycelium.In this study,we analyzed all the possible components that could be possibly from the wood decay for the induction of triterpenoids production of G.lucidum and in the liquid culture.After optimization of induction dosage and time,the results showed that,among 12 kinds of testing compounds,micro crystalline cellulose(MCC)had the most significant effect,followed by galactose.We found that triterpenoids production increased 85.96%by 1.50%MCC and 58.90%by 0.50%D-galactose.By quantitative reverse transcrition polymerase chain-reaction(qRT-PCR)analysis,we found out that the level of HMG-CoA reductase(HMGR),squalene synthase(SQS)and lanosterol synthase(LAS)genes expression were greatly induced by MCC and D-galactose,by 2.OOtimes,4.00 times and 2.50 times.In this study,we also treated G.lucidum with high and low temperature,light and darkness,to analyse the influence of them on G.lucidum triterpene production.Under the precondition that does not affect the growth of G.lucidum mycelium.Treatment at 4 ? for 2 h can make G.lucidum triterpene yield increased by 33.30%,and 37 ?stimulation can make G.lucidum triterpenoid yield increased by 27.80%.Though the light from the darkness alternating stimulus has no influence of the accumulation of G.lucidum triterpene,but it increased the biomass of G.lucidum mycelium.qRT-PCR analysis results show that temperature and light stimulus promoted HMGR,SQS and LAS genes expression,Among them,4 ? stimulation has the most significan improvment,by 3.00 times,20.00 times and 3.50 times.