Studies On Fermentation, Isolation And Characterization Of A Novel Antifungal-antibiotic

A novel antifungal antibiotic, was fermented,isolated and purified from the fermentation broth of Streptomyces ahygroscopicus ZU-1.The fermentation conditions were optimized by single-factor experiment.The optimum culture conditions were as follows: initial pH 7.0, 30℃, inoculum percentage 10%, medium loadage 40ml/250ml, fermentation time 72h.In the reversed jet loop reactor (JLR), the antibiotic productivity was the highest in 48 hours.The physical and chemical properties of the antibiotic were studied. The results showed the antibiotic was stable in hot and acid conditions, but not in an alkaline one. The experiments of Paper chromatography and paper electrophoresis showed the antibiotic might be acid and water-soluble.By UV scanning, its obvious absorption peak was observed at 298nm.Experiments showed that the antibiotic could effectively inhibit Candida albicans and MIC is 0.3906μg/mL.After pretreatment of fermentation liquor, solvent extraction, macroporous resin adsorption chromatography and ion-exchange chromatography were used one by one to purify the antibiotic . Then, the operating conditions for macroporous resin adsorption chromatography were optimized as follows: initial pH 4.0, flow rate 2BV/h for adsorption, 1BV/h for desorption, 80% ethanol solution as the mobile phase; and, the operating conditions for ion-exchange chromatography were optimized as follows: initial pH 2.0, flow rate 2BV/h for adsorption, 1BV/h for desorption, 0.6mol/L NH3H2O solution as the mobile phase. Three major configurations were found after preparative HPLC and the purity of P-1 is over 97%...