Producing biodiesel in E. coli

The Escherichia coli, or E. coli, bacteria.

Researchers have produced in the bacterium Escherichia coli hydrocarbons that are replicas of the petroleum-based molecules used in retail transportation fuels. Current biofuels containing alcohol or biodiesel require elaborate processing and are not fully compatible with most modern engines. John Love from the University of Exeter, U.K., and colleagues sought to create a biofuel that mimicked the properties of petroleum. They isolated metabolic genes from multiple species of bacteria and pieced them together in E. coli to create artificial biochemical pathways that convert free fatty acids to hydrocarbons. One such pathway, named CEDDEC, contained metabolic genes from the bioluminescent bacterium Photorhabdus luminescens and the cyanobacterium Nostoc punctiforme. When grown in broth containing various combinations of fatty acids, or when modified to express additional genes, the engineered E. coli produced molecules that are structurally and chemically identical to 10 retail diesel fuel hydrocarbons commonly used in temperate climates, says a report in a recent issue of Proceedings of the National Academy of Sciences (PNAS). According to it, the findings illustrate how artificial molecular pathways can be used to produce components of renewable, industrial fuels.