Overproduction of free fatty acids in E. coli: Implications for biodiesel production
Overproduction of free fatty acids in E. coli: Implications for biodiesel production
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DOI：
10.1016/j.ymben.2008.08.006
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发表时间：
2008-11-01
影响因子：
8.4
通讯作者：
Khosla, Chaitan
中科院分区：
文献类型：
--
作者：
Lu, Xuefeng;Vora, Harmit;Khosla, Chaitan
虽然生产乙醇和相关酒精生物燃料的微生物发酵工艺已经很成熟，但生物柴油（脂肪酸甲酯）完全来自植物油。工程油籽代谢的缓慢周期和副产品甘油的过度积累是从植物中提取生物柴油的两个主要缺点。尽管大多数细菌产生脂肪酸作为细胞包膜前体，但脂肪酸的生物合成在多个水平上受到严格调节。通过在大肠杆菌基因组中引入四种不同的遗传变化，我们设计了一种高效的脂肪酸生产者。在分批补料、限定培养基发酵条件下，该代谢工程大肠杆菌菌株生产了 2.5 g/L 脂肪酸，比生产率为 0.024 g/h/g 干细胞团，碳源转化为脂肪酸产品的峰值转化效率为 4.8%。所产生的脂肪酸中至少 50% 以游离酸形式存在。 (C) 2008 Elsevier Inc. 保留所有权利。
Whereas microbial fermentation processes for producing ethanol and related alcohol biofuels are well established, biodiesel (methyl esters of fatty acids) is exclusively derived from plant oils. Slow cycle times for engineering oilseed metabolism and the excessive accumulation of glycerol as a byproduct are two major drawbacks of deriving biodiesel from plants. Although most bacteria produce fatty acids as cell envelope precursors, the biosynthesis of fatty acids is tightly regulated at multiple levels. By introducing four distinct genetic changes into the E. coli genome, we have engineered an efficient producer of fatty acids. Under fed-batch, defined media fermentation conditions, 2.5 g/L fatty acids were produced by this metabolically engineered E. coli strain, with a specific productivity of 0.024 g/h/g dry cell mass and a peak conversion efficiency of 4.8% of the carbon source into fatty acid products. At least 50% of the fatty acids produced were present in the free acid form. (C) 2008 Elsevier Inc. All rights reserved.