Studies On L-Isoleucine-Producing Strain Fermentation Control

According to the theory of metabolic control fermentation, the dissertation focuses on fermentation condition of L-isoleucine producing strainTC-21 and how to control the fermentation process. The main research contents and results are as follows:(1) The method of oxidation colorimetric was defined to determinate L-isoleucine content quantitatively in the fermentation broth.The application conditions of this method was studied.(2) The batch fermentation condition of strain TC-21 in shake flask was studied in this dissertation. The proportions of seed medium and fermentation medium were optimized by orthogonal design experiment and response surface analysis of SAS software .The seed culture conditions and fermentation conditions were also studied.Under the optimum condition, strain TC-21 could produce L-isoleucine 21.18g/L after fermentation for 96 hours by flask-shaking batch fermentation.(3) The L-isoleucine fermentation process of strain TC-21 in 5-liter fermentor was studied. The batch fermentation was analyzed, the fermentation process dynamics and the strain morphology of strain TC-21 in the fermentation process were studied. The dissertation focuses on grading-fermentation control model and fed fermentation of L-isoleucine producing strain TC-21. Under the optimum condition, strain TC-21 could produce L-isoleucine 23.58g/L(4) Based on the experimental data from the anaphase fermentation of L-isoleucine producing strain TC-21 studying the metabolic flux transfer variance analysis. The effect of grading-fermentation control model and fed-fermentation on the the metabolic flux transfer variance was studied. All these would promote the furthermore development of the strain in the fermentor.The L-isoleucine producing strain TC-21 could produce L-isoleucine 23.58g/L in 5 liter fermentor and whose genetic character was very stable in the ferment process. The application of metabolic flux transfer analysis on L-isoleucine fermentation in 5L fermentor, Which could further help to study and develop, and to optimize the metabolic flux of L-isoleucine biosynthesis.