期刊
METABOLIC ENGINEERING
卷 13, 期 6, 页码 674-681出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.ymben.2011.08.004
关键词
Biofuel; Isobutanol; Metabolic engineering; E. coli
资金
- Office of Science of the U.S. Department of Energy [DE-AC02-05CH11231]
- NSF [0903955]
- Direct For Biological Sciences
- Div Of Molecular and Cellular Bioscience [0903955] Funding Source: National Science Foundation
Higher alcohols such as isobutanol possess several physical characteristics that make them attractive as biofuels such as higher energy densities and infrastructure compatibility. Here we have developed a rapid evolutionary strategy for isolating strains of Escherichia coli that effectively produce isobutanol from glucose utilizing random mutagenesis and a growth selection scheme. By selecting for mutants with the ability to grow in the presence of the valine analog norvaline, we obtained E. coli NV3; a strain with improved 24-h isobutanol production (8.0 g/L) in comparison with a productivity of 5.3 g/L isobutanol obtained with the parental wild type strain. Genomic sequencing of NV3 identified the insertion of a stop codon in the C-terminus of the RNA polymerase sigma(s)-factor, RpoS. Upon repair of this inhibitory mutation (strain NV3r1), a final isobutanol titer of 21.2 g/L isobutanol was achieved in 99 h with a yield of 031 g isobutanol/g glucose or 76% of theoretical maximum. Furthermore, a mutation in IdhA, encoding D-lactate dehydrogenase, was identified in NV3; however, repair of LdhA in NV3r1 had no affect on LdhA activity detected from cell extracts or on isobutanol productivity. Further study of NV3r1 may identify novel genotypes that confer improved isobutanol production. (C) 2011 Elsevier Inc. All rights reserved.
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