Optimization Of TMS-26Taxol Producing Fermentation System On Precursors, Elicitors And Fermentation Conditions

Paclitaxel is a kind of diterpenoid compound, mainly made up of a diterpenoid corecomposed of three main rings and an amphetamine serine side chain, it is a complexsecondary metabolite seperated from the Taxus plants, and is the only medicine that canpromote the tubulin polymerization and stabilize the aggregated microtubule. Paclitaxel ishighly concerned because of its unique anti-cancer mechanism, excellent anti-cancer effects,great demands as well as its low production. However, the traditional method of producingpaclitaxel may damage the environment, and the texus chinensis has been endangered.Searching an endophytic fungi with high production of paclitaxel and conducting themicrobial fermentation is therefore a promising way to obtain paclitaxel. So far, the industrialproducing requirements are hardly to be met because of the low production of endophyticfungi obtained by separation method. The paclitaxel yeild can be effectively improved byoptimizing the conditions of fermentation process as well as adding precursors and elicitors,providing relative data and technical support for paclitaxel industrail mass production.The tester strain was separated from the stem of nine-year Taxus media, found inNorthwest A&F University Expo, shaan xi province, and was identified as Aspergillusfumigatus variant, named Aspergillus fumigatus TMS-26. By introducing the procursor andelicitor substances and by optimazing fermentation process in the experiments, the taxolproduction under different optimization conditions was then measured by UVspectrophotometry at227nm, in order to explore the optimal condition for taxol productionand improve its productivity for industrial use.The main research methods and results are as follows：1. Effects of precursors and elicitors on biosynthesis of taxol have been researchedthrough single factor test and orthogonal test, conclusion has been made that the taxol yieldreached maximum446.28μg/L when introducing in the fermentation broth phenylalanine20mg/L, sodium benzoate30mg/L, sodium acetate8g/L, glycine15mg/L, CuSO40.05mg/L,H2O26mmol/L, and3,5-Dinitrosalicylic acid15mg/L. The yeild result is1.47times than thatof the case without elicitor (304.34μg/L). Therefore, Adding the precursors and elicitors inthe fungus (Aspergillus fumigatus TMS-26) fermentation broth can effectively improve thetaxol yield. 2. Effects of fermentation conditions on biosynthesis of taxol have been researchedthrough single factor test and orthogonal test, conclusion has been made that the paclitaxel ofthe strains arrived its optimal yeild (380.04μg/L) when the pH was7.5, inoculation quantity5%, the volume of liquid120/250mL, fermentation time was10days. The result is improvedby24.87%compared to the case before optimization (304.34μg/L). Therefore, the taxol yieldvaries by changing the fermentation conditions.