Studies On The Optimization Of Fermentation Conditions For Zuelacmycin-producing Strain GAO-1-GR-2 And Distraction Characteristics For Bioactive Substances

In order to improve the titer of Rui-la GAO-1-GR-2, the fermentation conditions and extraction process of crude active-product were optimal designed, working this way, they greatly increased production, and reduced the cost, lay foundations for manufacturing.The zuelacmycin-producing strain Streptomyces venezuelaevar. qinlingensis RL-2 was used as foundation. Integrative plasmid (pSET152) and composite plasmid were used for the starting plasmid in the streptomyces, then the heredity characters of fermentation titer of engineering bacteria was earned by escherichia coli (Escherichia coli)ET12567(pUZ8002) and fermentation broth of Zuelacmycin-yielding strain which were combined and shifted bettwen intergeneric.The fermenting conditions of Rui-la GAO-1-GR-2 were studied; the culture medium and culture condition for Streptomyces which produced antibiotic were optimized by orthogonal design. Fermentation conditions were studied, the results show that:yeast and soybean cake powder are better for organic nitrogen sources; glucose and caramel are better for carbon source. But taking the cost of fermentation into account, glucose 2% is better. Fermentation medium should be neutral, so natural pH between 7 and 8 is better. Otherwise it will inhibit the activity of fermentation product; with ventilation reaching 1:0.5,20% oxygen consumption can be reduced; 140r/min, temperature 30℃, fermentation time 72h.The titer of the original powder of fermentation can reach 4000μg/ml.The crude active-product of Rui-la GAO-1-GR-2 has a wide-range of inhibition, 1mg/1 materials has an inhibition efficiency above 65% against Pyricularia oryzae,Fusarium graminearum,Botrytis cirerea,Alternaria alternata and Erwinia carotovora et al.Based on fermentation broth of Zuelacmycin-high-yielding strain GAO-1-GR-2, antifungal active substances were extracted from the fermentation broth on the conditions of different extracting temperatures and five different kinds of macroporous adsorption resins. Phyricularia grisea was used as indicating microorganism. The results showed that the optimum extracting temperature was 60℃and macroporous adsorption resin HP-20 had better adsorption effect to active substances. After the optimization of absorption conditions, the optimum pH of sample was 6.0, optimum absorption velocity was 2.0 mL-min-1, the optimum component of eluent was 50% methanol,70% ethanol and 30% acetone (V/V), the optimum velocity of eluent was 1.5 mL-min-1.