‘Stitching together’ bacteria for better biofuel production

An engineer at Washington University in St. Louis has refined the process of engineering pathways of microbes for biofuel production. Fuzhong Zhang, an associate professor at the School of Engineering & Applied Science, has ‘stitched together’ the best bits of several different bacteria to synthesize a new biofuel product that matches current engines better than previously produced biofuels, according to an article on the University’s website.

“My lab is interested in developing microbial biosynthetic processes to make biofuels, chemicals, and materials with tailored structures and properties,” Zhang explained to the Source.

“Previously, we engineered E.coli to produce a precursor compound that leads to the production of advanced biofuels. In this work, we took the next step toward the actual manufacture.”

Zhang’s research focuses on engineering metabolic pathways which can be optimised to allow bacteria to act as a biofuel generator. Published in the journal Biotechnology for Biofuels, Zhang used elements of other bacteria to enable E.coli to produce ‘branched, long-chain fatty alcohol (BLFL)’, which can be used as a freeze resistant, liquid biofuel.

"We designed and then constructed a synthetic metabolic pathway inside the fast-growing E.coli by introducing genes from other species, including Staphylococus aureus, cyanobacteria and soil bacteria,” Zhang explained. “By using CRISPR, we incorporated genes from different species with favourable traits into E.coli’s fatty acid pathway.”


Addressing a common biofuel problem

The study found that Staphylococus aureus was particularly helpful for solving a common problem with biofuel manufacturer: 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 in cold weather.

Zhang’s lab is currently working with other labs at Washington University towards moving the metabolic pathway into more industrial relevant microbial host.