The Study On Fermenttaive Conditions Of Producing Glutamine

The research work in this study included: 1) optimizing the fermentation conditions of Glutamine production by mutant strain SH-77, 2) studied the control conditions in a 20L fermention jar, 3) searched the recovery of glutamine from fermentation broth.First the research studied the effect of many factors on the glutamine production such as metal ion, the content of CaCO₃, pH. Three main factors including the concentration of the NH₄Cl, glucose, corn-steep liquor in the medium was optimized through orthogonal method. Optimal medium was composed of (%) glucose 16, NH₄Cl₄, corn-steep liquor 0.5, K₂HPO₄ 0.05, KH₂PO₄ 0.05, FeSO₄ 0.5mg, MnSO₄ 2.5mg, ZnSO₄ 0.5mg, MgSO₄ 0.05, urea 1.4. Optimal fermentation conditions were fermentation time 72 hours, medium original pH 7.0, temperature 35℃, the rotary speed of the shaking-bed was 350r/min.In a 20L fermention jar, temperature, pH and the revolution of whisk was studied. The study indicated that the best control condition was temperature 32℃-38℃, pH 7.0-6.2, revolution of whisk 500 rpm. The average output of the Glutamine achieved 52g/L under these conditions.At last, the recovery of glutamine from fermentation broth was studied systematically. The feasibility of the ion-exchange method was also studied. Four resins were chosen and their exchange capability at different pH was studied. The ion-exchang resin D330 was selected through experiments. In separating glutamine from glutamic acid, we got the best conditions though the experiments. The results suggested that the D330 resin had the best separatation effect at the pH 3.4. Finally we got a glutamine yield rate of above 60%. This technology had such advantages as good separation effect, large capacity and easy control. It will have a bright future in industry.