生物谷报道：“高级”醇类作为生物燃料比乙醇有优势，因为它们能量密度更高、吸水性更低；“支链”醇类比直链醇类有更高辛烷值。过去，一直无法用原生微生物来生物合成这些醇类。现在，研究人员通过基因工程手段对大肠杆菌进行改造，已经可以用它们来从葡萄糖生产高级醇（包括异丁醇、1-丁醇和2-苯乙醇）。该方法涉及对氨基酸生物合成通道中的中间体进行分流，来合成想要的醇类，它可帮助通过微生物发酵来大规模生产生物燃料。
生物谷推荐英文原文：
Nature 451, 86-89 (3 January 2008) | doi:10.1038/nature06450; Received 4 May 2007; Accepted 2 November 2007
Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels
Shota Atsumi1, Taizo Hanai1 & James C. Liao1,2
Department of Chemical and Biomolecular Engineering,
UCLA-DOE Insitute for Genomics and Proteomics, University of California, Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, California 90095, USA
Correspondence to: James C. Liao1,2 Correspondence and requests for materials should be addressed to J.C.L. (Email: liaoj@seas.ucla.edu).
Global energy and environmental problems have stimulated increased efforts towards synthesizing biofuels from renewable resources1, 2, 3. Compared to the traditional biofuel, ethanol, higher alcohols offer advantages as gasoline substitutes because of their higher energy density and lower hygroscopicity. In addition, branched-chain alcohols have higher octane numbers compared with their straight-chain counterparts. However, these alcohols cannot be synthesized economically using native organisms. Here we present a metabolic engineering approach using Escherichia coli to produce higher alcohols including isobutanol, 1-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol from glucose, a renewable carbon source. This strategy uses the host's highly active amino acid biosynthetic pathway and diverts its 2-keto acid intermediates for alcohol synthesis. In particular, we have achieved high-yield, high-specificity production of isobutanol from glucose. The strategy enables the exploration of biofuels beyond those naturally accumulated to high quantities in microbial fermentation.
