Power-generating bacteria could fuel future tech

May 02, 2025

Scientists have found that some bacteria breathe by generating electricity. The natural process pushes electrons into their surroundings instead of breathing oxygen. The mechanism is expected to enable new developments in clean energy and industrial biotechnology.

A team led by Rice University bioscientist Caroline Ajo-Franklin identified how these bacteria expel electrons externally. The new study offers a glimpse into a previously hidden strategy of bacterial life.

Ajo-Franklin, professor of biosciences and director of the Rice Synthetic Biology Institute, stated that the research not only solves a long-standing scientific mystery but also points to a new and potentially widespread survival strategy in nature.

Bacteria’s electrochemistry could lead to energy innovations

The latest findings in bacteria’s electrochemistry are expected to lead to modern energy innovations.

Researchers underlined that most modern organisms rely on oxygen to metabolize food and release energy. Oxygen serves as the final electron acceptor in a chain of reactions that produce energy. However, bacteria, far older than modern organisms such as humans and plants, have evolved other ways to respire in oxygen-deprived environments, including deep-sea vents and the human gut, according to the study.

Bio-scientists have also highlighted that some bacteria use naturally occurring compounds called naphthoquinones to transfer electrons to external surfaces. This process, known as extracellular respiration, mimics how batteries discharge electric current, enabling bacteria to thrive without oxygen, as per a press release.

Diverse microbes utilize redox shuttles to exchange electrons

Published in the journal Cell, the study reveals that diverse microbes utilize redox shuttles to exchange electrons with their environment through mediated extracellular electron transfer (EET), supporting anaerobic survival. Although mediated EET has been leveraged for bioelectrocatalysis for decades, fundamental questions remain about how these redox shuttles are reduced within cells and their role in cellular bioenergetics.

“Here, we integrate genome editing, electrochemistry, and systems biology to investigate the mechanism and bioenergetics of mediated EET in Escherichia coli, which has been elusive for over two decades. In the absence of alternative electron sinks, the redox cycling of 2-hydroxy-1,4-naphthoquinone (HNQ) via the cytoplasmic nitroreductases NfsB and NfsA enables E. coli respiration on an extracellular electrode,” said researchers in the study.

Biki Bapi Kundu, a Rice doctoral student and first author of the study, stated that this newly discovered mechanism of respiration is a simple and ingenious way to get the job done.

“Naphthoquinones act like molecular couriers, carrying electrons out of the cell so the bacteria can break down food and generate energy.”

Researchers simulated bacterial growth in environments devoid of oxygen but rich in conductive surfaces using advanced computer modeling.

Bacteria could sustain themselves by discharging electrons externally

The simulations revealed that bacteria could indeed sustain themselves by discharging electrons externally. Further laboratory tests confirmed that bacteria placed on conductive materials continued to grow and generate electricity, effectively breathing through the surface, as per the release.

Better management of electron imbalances could significantly improve wastewater treatment and biomanufacturing. It’s also claimed that electricity-exhaling bacteria could fix these imbalances to keep the systems running efficiently.

“The work lays the foundation for harnessing carbon dioxide through renewable electricity, where bacteria function similarly to plants with sunlight in photosynthesis. It opens the door to building smarter, more sustainable technologies with biology at the core,” said Ajo-Franklin.