Breeding Of A Jinggangmycin Producing Strain And Optimization On Fermentation Conditions

Jinggangmycin is a agricultural antibiotic which produced by a strain that found in jinggang mountain area. Jinggangmycin has a particular sterilizing effects on Rice sheath blight, and also nice sterilizing effects on rice blast, wheat sheath blight. Besides, Jinggangmycin also uesd for preventing and curing plant diseases and insect pests of other crops. Though, Jinggangmycin had been found over 30 years, it is always popular to farmers for its highly active, low toxicity, no pesticide resistance and being friendly to environment.The yields of the start strain J1 is 20007μg/ml. The strain improvement studies of Strepto myces hyroscupicus var. Jingganggensis were carried out by ultraviolet radiation and DES as mutagens. One jinggangmycin high-producing strain of Strepto myces hyroscupicus var. Jingganggensis, J1-U-38-26 was selected. And the fermentation conditions for Jinggangmycin producing strain were studied. The yields of Jinggangmycin producing Strain was increased a lot. The results were as follows:1. The initial strain J1(with yields of 20007μg/ml )was treated by means of ultraviolet radiation and DES mutagenesis. A strain with higher yields acqucired from ultraviolet radiation was selected as the starting strain of the DES mutagenesis. Strain J1-U-38(with yields of 22695μg/ml)was got by ultraviolet radiation, strain J1-U-38-26(with yields of 25874μg/ml)was got by DES mutagenesis. And the final yields of the strain J1-U-38-26 was 25874μg/ml, increased by 29ï¼…than the start strain. Ultraviolet radiation contributed 45.8ï¼…to the improvement of the production. DES mutagenesis contributed 54.2ï¼…to the improvement of the production.2. In the study of the fermentation conditions for Jinggangmycin producing strain J1-U-38-26, The optimal culture medium for fermentation were shown as follows: solubility starch 12ï¼…,yeast powder 4ï¼…,KH₂PO₄ 0.05ï¼…,Nacl 0.25ï¼…. The optimum fermentation conditions were predicted as below: pH7.2 before sterilized, inoculated volume 8ï¼…, fermentation temperature 37℃, fermentation time 96h. And the final yields of the strain was 30610μg/mL, increased by 53ï¼…than the start strain.3. Establish and perfect yields testing ways which are mainly of HPLC to assure the stability and security of test.