| Triterpenes and polysaccharide are the main active ingredients of Ganoderma lucidum,which have extensive pharmacological effects,The development of liquid submerged fermentation technology has overcome the traditional problems of culture of G.lucidum,and become a major technology for producing main active ingredients of Ganoderma lucidum.In thesis,based on the previous studies in our laboratory,different exogenous substances were selected for effeciently production of triterpenes by G.lucidum mycelia,and the fermentation parameters were optimized,and then scale-up experiment has been carried out in 5L mechanical agitation tank,and fermentation kinetics models of triterpenes fermentation after adding the coix seed oil.thus fermentation technology for efficiently production of triterpenes by G.lucidum were developed.The main result are as the following:1.Effect of various allogenic material on triterpene liquid submerged fermentation was studied by using G.lucidum CCGMC5.616,with snp,praseodymium nitrate hexahydrate,neodymium nitrate hexahydrate,methyl jasmonate,ammonium ceric nitrate,sodium selenite.The results showed that coix seed oil as the best foreign substances for improved triterpenes production in flask-shaking test.2.(1)Box-Benhnken design combined with response surface methodology was applied to optimize the levels of three key parameters and study their interaction on Ganoderma lingzhi triterpenes production.The results showed that the three facts and the interaction of AB,AC were Extremely significant to production of Ganoderma lingzhi triterpenes.A polynomial model is established to predict the Ganoderma lingzhi triterpenes production as:Y=43.76-0.39A-0.46B-3.64C-0.082AB +0.1AC+0.0045BC-11.39A2-10.96B2-8.04C2.Analysis of response optimization suggests that the optimum medium forGanoderma lingzhi Triterpenes production is adding concertrations of coix seed oil is 3%and the adding time is the 2d and the pH is 6.9.All this adds up to a true test,the output of ganoderma lucidum triterpenes is(44.01±0.17)mg/g,6.04 time increased by comparing the original process.(2)The coix seed oil composition analysis shows that,the acid is the main ingredient,accounting for 89.54%of the total content.Through analyzing acids material inspection,found the main components of the acids material consists of octadecenoic acid(oleic acid),hexadecanoic acid(Palmitic acid),leinoleic acid(linoleic acid),and a handful of octadecanoic acid(stearic acid)and relative contents were 49.26%,17.83%,31.94%and 17.83%respectively.3.Based on the optimization of adding exogenous substances the coix seed oil,a scale-up experiment is carried out 5 L fermentor,with the speed of 160 r/min,50%dissolved oxygen,temperature of 25.8?.The experiment found that the biomass reached peak value when pH is 5.0,and the triterpene reached peak value when pH is 4.5.Based on that the two stage control pH strategy has been put forward:0?72h in fermentation of pH is not controlled,when the pH value around 4.5 and control of its stability in 4.5 until the end of fermentation,at this time of ganoderma fermenting biomass and intracellular triterpene ganoderma,received a significant improved,it increased by 4.97%and 19.62%respectively when compare the group of not control the pH.4.After adding the coix seed oil,we discovered that triterpene acids formed in parallel with mycelium growth in liquid fermentation of G.lucidum.Based on Sigmoid model,fermentation dynamics models of triterpene acids was founded.A dynamics model about cell growth,consumption of starch,and ganoderma lucidum terpene synthesis.The experimented values matched well with the models,which indicates that the model can reveal the basic characteristics of triterpenes fermentation process,and can be also used to predict the fermentation process of intracellular triterpene concentration changes after adding the coix seed oil.These result also can provide the theoretical foundation for industrial production of G.lucidum triterpenes in the future. |
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