New Pathways, Better Biofuels

by Erika Ebsworth-Goold (Washington University in St. Louis/The Source) An engineering team at Washington University in St. Louis is using e. coli to manufacture biofuel. New research from the lab further refines the process. ... Scientists have previously engineered metabolic pathways of microbes, making them tiny biofuel factories. Now, new research from an engineer at Washington University in St. Louis further refines the process, stitching together the best bits of several different bacteria to synthesize a new biofuel product that matches current engines better than previously produced biofuels.

Zhang’s (Fuzhong Zhang, associate professor at the School of Engineering & Applied Science) research focuses on engineering metabolic pathways that, when optimized, allow the bacteria to act as a biofuel generator. In its latest findings, recently published in Biotechnology for Biofuels, Zhang’s lab used the best bits of several other species — including a well-known pathogen — to enable E.coli to produce branched, long-chain fatty alcohol (BLFL), a substance that can be used as a freeze-resistant, liquid biofuel.

Zhang and his team determined that staph was particularly helpful to solve a common problem when manufacturing biofuel: The virulent pathogen was able to incorporate branches into its lipid. These branch structures dramatically lower the melting temperature of lipids and transform long-chain fatty alcohol from a waxy substance to a liquid that can be better used as a fuel under cold weathers.

Integrating the different species’ genes into E.coli also yielded another result: Normally, E.coli cannot produce any branched lipid on its own, but with the engineered metabolic pathway, 75 percent of the E. coli produced biofuels is branched.

Zhang says the next step involves moving the engineered metabolic pathway into a more industrial-relevant microbial host. READ MORE Abstract (Biotechnology for Biofuels)