Study On Flavomycin Rational Sceening And Fermentation Process Optimizition

Flavomycin, was effective on a wide variety of crops. The development of that product has the good and economic performance and social performance. In this dissertation, strain improvement, optimization of Flavomycin fermentation process and scale-up of fermentation processes in 10L fermentor were studied.1. According to the biosynthesis pathway and the metabolic regulation of Flavomycin, strain improvement was performed by mutation and rational screening to improve the productivity. Through treatment by rational screening and mutagens such as UV, NaNO₂ and microwave etc. Flavomycin over-producing strain sg2-N-8 was obtained. Productivity of strain sg2-N-8 reached 745u/ml, which was 7.2-fold higher than that of the original strain. Subculture test indicated that the hereditary character of strain sg2-N-8 was stable.2. The fermentation medium of mutant was optimized by PB design of experiment, with optimized medium in broth, which consisted of glucose 10.0g/L, bean cake powder 132.5g/L, rice flour powder 27g/L, starch 37.5g/L, (NH₄)₂SO₄ 2.5, MgS0₄·7H₂O 0.15,CaCO₃ 2.4, KH₂PO₄ 0.08, pH7.5, and the titer reach 867u/ml.the results showed that adding 10μg/ml Fe²⁺ and 30μg/mI Zn²⁺ to the medium are favor of productivity of Flavomycin, especially adding 30μg/ml Zn²⁺;However, adding Cu²⁺, Mn²⁺ to the medium did harm to productivity of Flavomycin;the abundant phosphate was advantageous to growth of strain, but restrained biosynthesis of secondary metabolite;adding glucose (15%) to the mediumwas favor of productivity of Flavomycin at 72h.3. The fermentation conditions of the mutant were optimized by flask, and were optimum fermentation conditions are inoculum size 10%, culture temperature 37*C, fermentation time 168h.4. By 10L bioreactor,the optimum fermentation conditions were investigated, and the results were stirring speed 600rpm, aeration 1.5wm ^\ culture temperature 37X1!, using The polyether subdues bubble pharmaceutical, fermentation time 168 h. The titer reached 1056U/mL with optimum fermentation conditions.