New insights into 3rd method of microbial energy production

Researchers have made a breakthrough in understanding the workings of the ‘third’ method of microbial production, known as ‘flavin-based electron bifurcation’ (FBEB). Their findings could be hugely significant for the world of microbial energy and biofuels.

The discovery of FBEB led to a drastic shift in the way scientists think about how organisms obtain energy. Now, researchers from Biological Electron Transfer and Catalysis (BETCy) Energy Frontier Research Center have gained an insight into the mechanism behind it. Their results have been published in the journal Nature Chemical Biology.

According to a statement from the US’ National Renewable Energy Laboratory (NREL): “One of the most important findings is how a unique flavin molecule is able to generate two levels of energy from a single precursor compound. One level is used to perform an easy chemical reaction, whereas the other much more energetic one is used to perform more difficult chemistry to form a high-energy compound. In doing so, the two reactions are coupled together so that energy that is normally wasted is conserved in the high-energy compound.”

Put simply, the unique flavin molecule greatly improves energy efficiency in FBEB.

The results should enable new strategies for engineering biological systems for more efficient production of fuels and chemicals and for developing catalytic processes that optimise conversion of electrochemical reactions," said NREL researcher Cara Lubner. "Understanding the biochemistry of bifurcation will enable more informed strategies for bioengineering microbes to produce higher levels of biofuels and reduced chemicals."

Funded by the Department of Energy’s Office of Science, the article was written by members of the BETCy, who are located at NREL, Montana State University, Arizona State University, the University of Georgia, and the University of Kentucky. 

"As we better understand the bifurcation method, we envision that new materials and catalysts might be designed that have the same increased efficiency at the important chemistries they perform," noted NREL scientist David Mulder.

As well as reducing by-products from catalytic processes, leading to savings in industrial processes, the greater understanding of the FBEB process could make it possible to take advantage of the energy-efficient pathways in living cells to engineer microbes to preferentially use them to make better products such as chemicals, fuels, or hydrogen gas.