Study On Antifungal Drugs Beauvericin And Its Optimization Of Fementation Process

Fusarium concentricum is marine fungi separate from marine which can produce beauvericin.Research about "Interaction of drug screening" revealed that Ketoconazole has significant antifungal effect Cooperate with BEA. We can reduce the dosage of Ketoconazole and weaken its toxicity.Deep liquid culture technology played an important role in BEA research, and it provided based data for the industrialization in the future. This paper did some system research of Fusarium concentricum,and focused on the culture medium, fermentation conditions and control strategy in50L reactor level. The main research conclusion was as follows:(1) On the media, we focused on carbon source, nitrogen source and its proportion, bacteria growth, product formation, dissolved oxygen level and the relationship of resulting bacteria.finally we get the best culture formula:glucose12.52g/L, starch33.9g/L, NaNC>31.63g/L, Casein11.63g/L, MgSO4.7H2O0.05g/L, K2HPO42g/L,NaCl0.5g/L, CaCO32g/L.(2) In the research of operation variables during the fermentation, we focused on the optimization about temperature, pH, fermentation period, shake bed speed, inoculation amount.And the conclusion was as follows:in the shake flask fermentation,the growth situation of fusarium is better when pH was6.5-7.0, fermentation temperature was27.5℃, later reduced by1-2℃,so that the growth of fusarium would speed up. The speed of wave bed was220rpm. Fermentation cycle was168h. The maximum amount of production was302.69mg/L.(3) Control strategy in the50L reactor was as follows:in the first3days, Stirring speed enhanced to400rpm slowly, ventilation volume was1.0wm;in the next2days, Stirring speed enhanced to600rpm,ventilation volume was1.2wm; in the last2days,Stirring speed descended to400rpm, ventilation volume was1.0wm. At the same time, we must keep OD above30%in earlier stage, and10%in later stage.in the process of fermentation, we must add saccharides and ammonia, we added10%glucose in72h later, and added28%ammonia in140h later. And we must keep pH at about6.9. When the fermentation ended, the output of BEA was488.24mg/L.All the conclusion above indicated the feasibility of deep liquid culture technology. And it provided theory basis for the next large-scale production.