Optimization On The Fermentation Media And The Conditions Of Bleomycins

Bleomycins that have antineoplastic property are a group of multi-component glycopeptide antibiotics produced by Streptomyces Vertillus. The difference of the components lies in the difference of the amine in the end. Bleomycins are broad antineoplastic medicine with low toxicity, they have a good curative effect on malignant lymphoma, and cancers of cervix, galactophore, esophagus, as well as liver cancer, which has a high incidence but no effective way to cure. So it is very important to improve the bleomycins content in the fermentation fluid.We optimize the components of the medium and the condition of culture, observe the impact of adding time and concentration of precursors on the yield of bleomycin. The impact of Carbon,organic substances, inorganic nitrogen,phosphate, and CuSO₄ on the fermentation of bleomycin. The optimum medium is: glucose1%, maltose 3%,soluble starch3%, soy peptone 0.5%, bean powder 3%, corn plasm1%, bean oil 0.5%, NaCl 0.3%, K₂HPO₄ 0.1 % , ZnSO₄ 0.05% , CuSO₄ 0.01% , NaNO₃ 0.3%. With the optimized fermentation medium, the yield of bleomycin produced by Streptomyces verticillus U-43 can reach 41.23μg/ml under the condition of flask culture. On the process of optimizing culture condition , impact of the innoculation time, innoculation content, primary pH of fermentation medium, flask column on fermentation have been studied.the results show that the innoculation time is 48h, optimum temperature 28℃, most appropriate primary pH 6.0, innoculation content 6%, flask column 80ml/500ml. After optimization of culture condition, the output can reach 46.11μg/ml. Using the optimised fermentation medium and condition,and addition of the precursor refined amine 0.04 mg/ml when the fermentation comes to 60h..Based on the results in shake flasks, bleomycin fermentation was scaled up in a 16L fermentor.The metabolic characteristic of Streptomyces verticillus U-43 in the 16L fermentor ,including pH, sugar and nitrogen metablization,biomass,dissolved oxygen, productivity of per unit.it is established that the critical point of the dissolved oxygen should be no lower than 20%, the fermentation period is 192 hours,and pH should be controlled at about 6.4,the findings of three consecutive fermentation show that the fermentation unit of bleomycin can reach 105.11 μg /ml.