BLACKSBURG, Va. — Feb. 23, 2016 — Two Virginia Tech researchers have made a leap forward in the science of powering fuel cells with wastewater, identifying a way to maximize the amount of electricity generated, according to a press release.

Xueyang Feng and Jason He traced bacteria, leading them to discover that the working relationship between two specific substrates produced more energy than either did separately. Reporting on the discovery, Virginia Tech said that it will help take the mystery out of how electrochemically-active bacteria create energy, and could help in the development of microbial fuel cells.

“Tracing the bacteria gave us a major piece of the puzzle to start generating electricity in a sustainable way,” commented Feng, an assistant professor of biological systems engineering, in the release. “This is a step toward the growing trend to make wastewater treatment centers self-sustaining in the energy they use.”

Not all organics perform the same job in the same way, Virginia Tech explained. While one substrate known as lactate is mainly metabolized by its host bacteria to support cell growth, another substrate known as formate is oxidized to release electrons for higher electricity generation.

Feng and He found that when these two substrates are combined, the output of energy is far greater than when they are working separately.

In an article published in Scientific Reports, they wrote: “Our results indicated a synergistic effect of formate and lactate on electricity generation, and extra formate addition on the original lactate resulted in more electrical output than using formate or lactate as a sole electron donor.”

The organics work in tandem with receptors in fuel cells. Although research using microbial fuel cells is not new, the kind of organics used by Feng and He is novel in generating electricity because they were able to measure the symbiotic nature of two particular organics, the university said.