Ginkgo Esters Strain And Fermentation Conditions To Produce A Preliminary Study

Ginkgolides are a kind of terpene lactones with great medical potential in central-nerve system and blood-brain barrier system,et al.It's also the most effective natural antagonist of platelet activating factor.Because ginkgolides are unique components of Ginkgo biloba L,which are reported to possess peculiar structure and remarkable pharmacological activities.The experiment ties to solve the problem of sustainable utilization of ginkgolides resource through using the feature that endophyte can produce some metabolites similar to those from the host plant and microbial fermentation.The experiment use the method of TLC and HPLC to screen out a high ginkgolides producing strain FG 052 from active endophytic fungi which were isolated from Ginkgo biloba L, morphologically identified as Aspergillus fumigatus var. fumigatus By taking FG 052 as starting strain, a higher productive mutant strain m₄-4 was obtained after UV mutation and compound mutation of UV and nitrous acid.The productivity reached 181 mg/L,which was 56% more than that of the parent strain Aspergillus fumigatus var. fumigatus FG 052.The mutant's genetic stability was good after five generations.The results of experimenting on optimum fermentation conditions of strain FG 052 showed that PDA is the optimum heredity culture medium for stain FG 052 growth and producing spores and Czapek is the optimum fermentation culture medium,the maximum amount of mycelia appeared at fermenting for 168 h,the maximum ginkgolides productivity appeared at 144 h and yield reached 0.13 mg/mL,pH is 4.86 here.Ginkgolides content in each flask is the highest when C/N is 10.Influence of C source,N source,pH on the ginkgolides production were studied systematically.Optimum medium components for ginkgolides production are as following :N source is NaNO₃(0.3 %), C source is glucose ( 3 % ),pH is 7.0.The optimum seed age was 18 h,the optimum liquid culture volume was 30 mL in 250 mL Erlenmeyer flask,the optimum inoculum amount was 1% of the liquid culture volume,and the optimum temperature was 26℃.The experimental research above lay a important foundation in studying the new resource of ginkgolide and industrialization production in future.