期刊
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
卷 78, 期 1, 页码 70-80出版社
AMER SOC MICROBIOLOGY
DOI: 10.1128/AEM.06785-11
关键词
-
资金
- LS9
- Amyris
- Lygos
- Office of Science, Office of Biological and Environmental Research, of the U.S. Department of Energy [DE-AC02-05CH11231]
We have engineered Escherichia coli to overproduce saturated and monounsaturated aliphatic methyl ketones in the C-11 to C-15 (diesel) range; this group of methyl ketones includes 2-undecanone and 2-tridecanone, which are of importance to the flavor and fragrance industry and also have favorable cetane numbers (as we report here). We describe specific improvements that resulted in a 700-fold enhancement in methyl ketone titer relative to that of a fatty acid-overproducing E. coli strain, including the following: (i) overproduction of beta-ketoacyl coenzyme A (CoA) thioesters achieved by modification of the beta-oxidation pathway (specifically, overexpression of a heterologous acyl-CoA oxidase and native FadB and chromosomal deletion of fadA) and (ii) overexpression of a native thioesterase (FadM). FadM was previously associated with oleic acid degradation, not methyl ketone synthesis, but outperformed a recently identified methyl ketone synthase (Solanum habrochaites MKS2 [ShMKS2], a thioesterase from wild tomato) in beta-ketoacyl-CoA-overproducing strains tested. Whole-genome transcriptional (microarray) studies led to the discovery that FadM is a valuable catalyst for enhancing methyl ketone production. The use of a two-phase system with decane enhanced methyl ketone production by 4- to 7-fold in addition to increases from genetic modifications.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据