Study On Optimize Fermentation Conditions For Producing Podophyllotoxin Of One Endophytic Fungi

Podophyllotoxin is a kind of anticancer and insecticidal lignans. It is an effective medicine in treating wart as well as a precursor of some anti-tumor medicine. Because of its great medical potential, podophyllotoxin had been demanded desperately. So far, many reports are about separating endophytic fungi which can produce podophyllotoxin from plants while fewer reports are about producing podophyllotoxin with microbiological fermentation method. Thus, how to raise the yield of podophyllotoxin and determine its content quantificationally become a hotspot.Objectives: Study the optimal fermentation condition of the strain Ty and establish a method which can determine podophyllotoxin's content in the fermentation process. Methods: In light of the characteristic of microbiological fermentation, refer to the TLC-scanning for detection of active ingredients in the medical plants to find a suitable detective way which can determine podophyllotoxin's content in the fermentation products easily. Design a synthesized medium which fits the fermentation of Ty basing on the PDA medium, optimize the fermentation conditions through choosing pH, amounts of inoculums, the liquid volume and fermentative cycle and take common methods for the identification of fungi to identify the strain Ty. Results: It was determined to adopt the TLC-scanning as detective method through the experiment of coefficient of precision, stability and mensurate recovery rate. The optimal composition of the synthesized medium were as follows: saccharose 1.5%, glucose 1.5%, starch 3%, peptone 0.05%, yeast extract 0.05%, NaCl 0.075% and K₂HPO₄ 0.075%;the optimum culture conditions were at temperature of 28℃, initial pH6.5, liquid capacity 80mL in 250mL flask, 2.5% inoculating amount, the fermentative cycle 7d and it was sure that the change of medium didn't influence theproduct's ingredients and property with the help of HPLC and ^-NMR. The initial identification result showed that the strain Ty belongs to Phycomycetes, Mucorales, Mucoraceae, Mucor Micheli ex Fries, M.disperses Hagem. Conclusions: TLC-scanning method relatively had the characteristics of reliability, accuracy and simplicity for determination of podophyllotoxin in the fermentation products of Ty. Using an in-house-made synthesized medium was obviously feasible for large scale fermentation of the strain Ty. Through optimizing the fermentation conditions, the biomass of Ty and the content of podophyllotoxin had been improved greatly, and these will be lay the foundation for industrialization of podophyllotoxin.