Study On Strain Breeding And Fermentation Process Of Demeclocycline

The secondary metabolite demeclocycline,which is tetracycline antibiotics,produced by Streptomyces aureofaciens.This paper had a process of strain breeding on the starting strain SIPI-L3105-22 by UV and microwave mutagenesis,then the high yield strain was selected by self-secondary metabolite,demeclocycline.Finally,potency of the strain named SIPI-L3105-A65,which was high yield and had resistance of self-secondary metabolites was 5790?g/ml and 39.3% higher than the starting strain.The fermentation process of SIPI-L3105-A65 was optimized.Firstly,the optimization of seed culture and fermentation conditions was attained.Based on the optimal conditions,a large of work was carried out on the optimization of fermentation culture.The optimum combination of carbon resource and nitrogen source is corn starch with sucrose and soybean powder with feather meals,corn steep liquor and supplemented?NH₄?₂SO₄.In addition,0.03% citrate,0.03% magnesium phosphate and 0.008% zinc acetate play role in the fermentation production improvement.Optimized medium composition and culture conditions result that 8371?g/ml of demeclocycline fermentation production,that was 44.5% higher than starting process,providing certain reference for fermentation tank amplification and industrial production.