Study On The Breeding Of High Production Strains And Fermentation Of Shennongmycin Ⅱ

Shennongmycin producing strain is a mutant of 5102 ( Streptomyces hygroscopicus van yingchengensis Yan et Ruan. n. var) . It is a new agricultural antibiotic showing multiple activity of inhibiting fungi of plant.The article is based on the quantity analysis to Shennongmycin II with the method of HPLC , strain breeding and the fermentation condition of Shennongmycin II .The results of the quantity analysis showed that the correlation coefficient, variability coefficient, rate of recovery to ShennongmycinIIwere 0.99947, 0.108%, 97.60-100.23% respectively.Through using six breeding methods to deal with Shennongmycin original strain ,finally,a mutant strain was gained, whose chemical potency wsa 4.0 times as much as the original one.Among the six breeding methods, the dealing potency of UV, microwave and N+ immiting was relatively good.On shaking flask lever, we screened the optimum carbon and nitrogen sources by single-factor experiment in fermentation media.Then, we screened the optimum level of every component of the fermentation media by orthogonal experiment.We also investigated the pH before sterilized, temperature, inorganic factor, volume and agitation.The optimum condition to higher chemical potency was obtained:fermentation media: corn flour 6%, fishmeal 1.8%, soybean powder 0.8%, K2HPO4 0.1%, NaCl 0.15%, CaCO3 0.4%, pH7.3-7.7before sterilized, temperature 28-30癈, volume30ml/150ml. We also concluded chemical potency was relevant to time, carbon, nitrogen, biomass but irrelevant to volume in my experiment condition. The chemical potency in optimum fermentation condition is 1.201 times as much as the one in the initial fermentation condition.