Microbial Biosynthesis of Alkanes
Toward Alkane Synthesis
Alkanes are major components of fossil fuels, and synthesis of alkanes remains a challenge in the conversion of renewable raw materials to fuels. Even though diverse organisms synthesize alkanes, synthesis pathways have remained elusive. Now Schirmer et al. (p. 559) describe an alkane biosynthesis pathway in cyanobacteria that converts intermediates of fatty acid metabolism to alkanes and alkenes. Heterologous expression of the biosynthetic genes resulted in production of alkanes in Escherichia coli. This pathway is likely to be a valuable tool in the production of biofuels.
Abstract
Alkanes, the major constituents of gasoline, diesel, and jet fuel, are naturally produced by diverse species; however, the genetics and biochemistry behind this biology have remained elusive. Here we describe the discovery of an alkane biosynthesis pathway from cyanobacteria. The pathway consists of an acyl–acyl carrier protein reductase and an aldehyde decarbonylase, which together convert intermediates of fatty acid metabolism to alkanes and alkenes. The aldehyde decarbonylase is related to the broadly functional nonheme diiron enzymes. Heterologous expression of the alkane operon in Escherichia coli leads to the production and secretion of C13 to C17 mixtures of alkanes and alkenes. These genes and enzymes can now be leveraged for the simple and direct conversion of renewable raw materials to fungible hydrocarbon fuels.
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Supplementary Material
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Published In
Science
Volume 329 | Issue 5991
30 July 2010
30 July 2010
Copyright
Copyright © 2010, American Association for the Advancement of Science.
Submission history
Received: 4 February 2010
Accepted: 16 June 2010
Published in print: 30 July 2010
Acknowledgments
We thank M. Alibhai for homology modeling, S. Brubaker for bioinformatics work, T. Baron for technical assistance, and C. Chang for help with preparing Fig. 3. The patent applications WO 2009/140695 and WO 2009/140696 are relevant to this paper. All authors have a financial interest in LS9, Inc. We would like to dedicate this paper to the memory of C. Richard Hutchinson, who died on 5 January 2010. “Hutch” was an important mentor for A.S. and S.B.d.C. He will be missed.
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