| Ganoderma lucidum is a medicinal fungi, which has been applied to the prevention and treatment of diseases more than 2000 years ago. Its main biological compositions are ganoderma polysaccharides and ganoderma triterpenes. Currently, Ganoderic acid is mainly obtained from fruit body of Ganoderma lucidum, far from enough to meet the market demand. Studies on submerged fermentation of Ganoderma lucidum indicate that fermentation process can produce ganoderic acid directly and obtain lots of Ganoderic acid. Ganoderma lucidum mycelium can be used to extract Ganoderic acid, can also be extracted other components or used in health products processing as a byproduct. The study in this article shows how to improve the output of Ganoderic acid by submerged fermentation method.Firstly, different additions of organic carbon source were added to culture broth in order to promote the growth of mycelium. The results showed that the mycelia biomass of Ganderma licidum and yield of ganoderic acid in mycelia treated with 4g/L corn flour were enhanced by 111% and 126%, respectively. The mycelia biomass of Ganderma licidum and yield of ganoderic acid in mycelia were up-regulated by 73% and 87%, respectively, compared with the control group when the addition of wheat flourwas 10g/L in culture solution. The mycelia biomass of Ganderma licidum and yield of ganoderic acid in mycelia were up-regulated by 97% and 115%, respectively, compared with the control group when the addition of buckwheat powder was 7g/L in culture solution. The content of ganoderic acid in mycelia reached peak, being 23.538mg/g, when 4g/L of corn flour was added to medium. However, there is no significant difference in the yield of ganoderic acid between 4,5,7 and lOg/L of wild corn flour. From the production practice,4g/L of corn flour was selected to apply to further experiment.Secondly, we studied how melotonin, Cu2+ and Ca2+ influence the ganoderic acid in the mycelia during submerged fermentation. The results showed that 20μmol/L of melotonin can significantly increase the ganoderic acid production by 73%, peaking at 244.528 mg/L compared with the control group. With 100 μmol/L of Copper sulfate as a Cu2+ donor, yield of ganoderic acid in mycelia reached 207.773mg/L, compared with the control group, Ganoderic acid production significantly increased by 57%. With 100-200 μmol/L of Calcium chloride as a Ca2+ donor, a remarkable increase in ganoderic acid titer was observed, being 187.061mg/L and 182.407 mg/L, respectively, compared with the control group, while the yield of ganoderic acid was increased by 29% and 26%, respectively. Exgenous substances of melation to study between add time and receipt time influencing the ganoderic acid in the mycelia during submerged fermentation, results show that the best timepoint of adding melotonin 20μmol/L was on day 4 and receipt was on day 9.In addition, the experiment that adding time of melotonin as well as receipt time of ganoderic acid was viewed as variable was performed when there was 4g/L corn flour in the culture medium. It was shown that the best timepoint of adding inducer to culture medium was on day 4, and the optimum timepoint of receipt mycelia was on day 8. Response surface method based on one factor experiment was used to study the alteration of mycelia biomass and ganoderic acid production during submerged fermentation under the conditions of corn flour medium, calcium chloride, copper sulfate, melotonin. It was concluded that the relationship between above three factors is linear of mycelia biomass and above three factors is not linear but complexed of ganoderic acid production. The equation is as follows:Y=38.41-0.50A+2.11B+0.96CIGA=406.75+3.77A+10.33B+9.08C-12.26AB-0.57AC-27.46BC+13.33A2+1.83B2 +1.60C2:(A:calcium chloride; B:copper sulfate; C:melotonin)Finally, Experimental results showed that adding 200μmol/L of Calcium chloride, Coppe sulfate 50μmol/L, melotonin 20μmol/L in the fourth day to the medium supplemented with 4 g/L corn flour can significantly increase production of Ganoderic acids.Ganoderic acid production reached 451.918mg/L, made the production of Ganoderic acid increased by 4.06 times. This dissertation also discussed and prospects the industrial production optimization process using Submerged fermentation to product Ganoderic acid. |
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