%0 Journal Article
%T Pathway analysis for production of L-leucine by Brevibacterium flavum TK0303<br>黄色短杆菌TK0303的L-亮氨酸生物合成途径分析
%A LIU Hui
%A CHEN Ning
%A WEN Ting-yi
%A <br>刘辉
%A 陈宁
%A 温廷益
%J 微生物学报
%D 2007
%I 
%X Brevibacterium flavum is used for the production of a number of amino acids in the biotechnology industry. The yield of producing a metabolite is ultimately limited by the ability of the central metabolism and the desired biosynthesis pathway. Pathway analysis is a very useful tool for metabolic engineering, which can be applied to increase the yield of a metabolite or channeling a metabolite into desired pathways. It does not require any kinetic parameters and only uses the Stoichiometric equations. Pathway analysis for production of L-leucine by Brevibacterium flavum TK0303 at steady state was conducted in this paper. Theoretical yield and flux distribution for optimal pathway were determined.It is also concluded that pyruvate and acetyl-coenzyme A are the key nodes of the L-leucine biosynthesis pathway by analyzing the flux distributions of different modes. According to the pathway analysis, the production of L-leucine is expected to be raised by strengthening the flux of the key nodes (pyruvate and acetyl-coenzyme A) through changing the environmental factors. Because the flux of TCA cycle in Brevibacterium flavum TK0303 is weak, the production of L-leucine must be provided enough amido by adding glutamic acid to the fermentation medium. NH_4Ac is both a carbon source and a nitrogen source, which could be helpful to the production of L-leucine. The effects of glutamic acid and NH_4Ac on the production of L-leucine were further studied. The production of L-leucine increased 56% by adding glutamic acid. By improving the concentration of NH_4Ac, the biosynthesis of L-leucine was greatly strengthened too. The results indicate that the flux of L-leucine can be largely increased by changing the chemical regulatory factors such as NH_4Ac and glutamic acid and the modes established by pathway analysis prove to be efficient to describe the metabolic network of L-leucine production by Brevibacterium flavum TK0303.
%K L-leucine
%K pathway analysis
%K Brevibacterium flavum<br>L-亮氨酸
%K 途径分析
%K 黄色短杆菌
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=A3C6BA55AB623B90FA9104CFFC826F3C&aid=6213A0B073EFA421&yid=A732AF04DDA03BB3&vid=F4B561950EE1D31A&iid=0B39A22176CE99FB&sid=D537C66B6404FE57&eid=82722E2B785EBF0D&journal_id=0001-6209&journal_name=微生物学报&referenced_num=0&reference_num=15