Study of L-Isoleucine fermentation oxygen controlling on the basis of Pathway analysis
基于途径分析的L-异亮氨酸发酵溶氧控制研究

Pathway analysis,the theoretical basis for gene operation and elementary method for metabolic network analysis,was conducted for production of L-isoleucine by Brevibacterium flavum TC-21.Metrology mode and some professional program were used in pathway analysis to establish the best metabolic mode of L-isoleucine.Metabolic engineering is used to restructure the metabolic flux in some pathways or to redirect the flux distributions in different pathways,and its target is to trim the primary metabolism to introduce the metabolic flux into the flux of end product.By analyzing the characteristic and process of L-isoleucine fermentation based on 5L autocontrol fermentor,it was proved that metabolic pathways could be changed by the environmental factors such as dissolved oxygen.According to experimental result and metrology analysis,the metabolic flux is related to the dissolved oxygen,so dissolved oxygen can influence the yield of L-isoleucine by changing the the metabolic flux.In contrast to stable oxygen supply,grading oxygen supply is more superior.L-isoleucine of 25.5g/L is accumulated by grading oxygen supply,and it is 15.77% higher than that of 20.26g/L by stable oxygen supply.On different stage of L-isoleucine fermentation,we can control oxygen supply to fulfill the different need of biomass growth and specific rate of L-isoleucine.The experimental conclusion is that oxygen supply on the basis of pathway analysis can be used in L-isoleucine fermentation.