Breeding Of L-Valine-Producing Strain And Studies On Its Fermentation Conditions

According to the theory of metabolic control fermentation, the dissertation focuses on the breeding, fermentation condition and fermentation kinetics of L-valine producing strain. The main research contents and results are as follows:[1] The measurement of L-valine was studied in the paper.The measure standard curve of L-valine was performed with paper chromatography.The relationship between the content of L-valine in fermentation broth and absorbency could be described by a expression.[2] One L-valine high-producing strain TV230 was derived from Brevibacterium flavwn TV 10 by protoplast UV induced and stepwise DES mutagenesis , which could produce L-valine 23.82 g/L under the fermentation condition without being optimized.[3] The optimal seed and fermentation medium were obtained by using neural network and genetic algorithms,at the same time the best condition was studied.The result shows that L-valine concentration was increased by 24% to the original yield.[4] According to the rule of substance-decreasing .strain-growing and product- making.The batch fermentation kinetics model was build by using neural network.The strain TV230 obtained has been potential to apply to industrial producing, whose genetic character was very stable. Based on the data in the 5L fermentor, The model would benefit the optimizing control of L-valine fermentation in industrial producing.