Metabolic Engineering of Escherichia coli for the Production of 1,2-Propanediol From Glycerol
Metabolic Engineering of Escherichia coli for the Production of 1,2-Propanediol From Glycerol
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DOI：
10.1002/bit.22993
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发表时间：
2011-04-01
影响因子：
3.8
通讯作者：
Gonzalez, Ramon
中科院分区：
文献类型：
--
作者：
Clomburg, James M.;Gonzalez, Ramon
由于其可获得性、低价格和高度还原性，甘油已成为用于生产燃料和还原化学品的有吸引力的碳源。利用我们已经建立的平台，从确定介导甘油发酵代谢的关键途径，这项工作报告了大肠杆菌的工程转化甘油成1，2-丙二醇（1，2-PDO）。一个功能性的1，2-PDO途径是通过过表达的基因参与其合成的关键中间体磷酸二羟丙酮（DHAP）和发酵甘油利用途径的操作的组合工程。前者包括甲基乙二醛合成酶（mgsA）、甘油脱氢酶（gldA）和醛氧化还原酶（yqhD）的过表达。通过替换天然E. coli PEP依赖的二羟丙酮激酶（DHAK）与C. freundii增加了DHAP的可用性，从而允许更高的1，2-PDO产量。主要发酵途径的分析确定乙醇作为所需的副产物，而通过破坏乙酸盐和乳酸盐生产的途径来实现1，2-PDO滴度和产率的增加。这些关键代谢操作的组合导致工程E。大肠杆菌菌株能够产生5.6g/L的1，2-PDO，产率为21.3%（w/w）。该菌株也表现良好时，粗甘油，生物柴油生产的副产品，被用作底物。本研究所获得的效价和产量均优于使用E.大肠杆菌从普通糖生产1，2-PDO。Biotechnol. Bioeng. 2011;108：867-879. (C)2010 Wiley Periodicals，Inc.
Due to its availability, low-price, and high degree of reduction, glycerol has become an attractive carbon source for the production of fuels and reduced chemicals. Using the platform we have established from the identification of key pathways mediating fermentative metabolism of glycerol, this work reports the engineering of Escherichia coli for the conversion of glycerol into 1,2-propanediol (1,2-PDO). A functional 1,2-PDO pathway was engineered through a combination of overexpression of genes involved in its synthesis from the key intermediate dihydroxyacetone phosphate (DHAP) and the manipulation of the fermentative glycerol utilization pathway. The former included the overexpression of methylglyoxal synthase (mgsA), glycerol dehydrogenase (gldA), and aldehyde oxidoreductase (yqhD). Manipulation of the glycerol utilization pathway through the replacement of the native E. coli PEP-dependent dihydroxyacetone kinase (DHAK) with an ATP-dependent DHAK from C. freundii increased the availability of DHAP allowing for higher 1,2-PDO production. Analysis of the major fermentative pathways indentified ethanol as a required co-product while increases in 1,2-PDO titer and yield were achieved through the disruption of the pathways for acetate and lactate production. Combination of these key metabolic manipulations resulted in an engineered E. coli strain capable of producing 5.6 g/L 1,2-PDO, at a yield of 21.3% (w/w). This strain also performed well when crude glycerol, a by-product of biodiesel production, was used as the substrate. The titer and yield achieved in this study were favorable to those obtained with the use of E. coli for the production of 1,2-PDO from common sugars. Biotechnol. Bioeng. 2011;108: 867-879. (C) 2010 Wiley Periodicals, Inc.