Screening The Mutant With Over-producing Echinocandin B And Improving Its Fermentation And Extraction Technology

Anidulafungin is playing a more and more important role in antifungal drugs marketing and being developed by several domestic biopharmaceutical companies. Echinocandin B(ECB) is a key intermediate for synthesizing compound anidulafungin and its production costs seriously affect anidulafungin manufacturing costs and market competitiveness. Therefore, it is essential to improve the producing strain and production technology. In this paper, based on the previous research in this laboratory, the ECB-producing strain and the fermentation & extraction isolation technology were improved.A strain named SIPI-MT2 kept in our lab was used as the starting strain. By using Ultraviolet irradiation and NTG treatment methods, one mutant named SIPI-W15 exhibited over- production of echinocandin B and its productivity showed 49.4% more than that of the original strain.By using single factor experiment and response surface experiment methods, the effects of fermentation media and conditions on ECB fermentation titers in flasks were investigated, and the optimal fermentation medium compositions and the culture conditions were obtained. Under the improved fermentation technology, the ECB fermentation titer of strain SIPI-W15 increased 55% compared with that of the original technology, which could reach 2013 μg/ml in the shake flask.For improving the extraction process of echinocandin B, the optimal extraction solvent was acetone and the optimal macroporous adsorption resin was SP825, and other isolation conditions were also improved. Compound ECB was obtained and its purity reached 95.3%.