Most organisms, humans included, depend on oxygen for survival. However, certain bacteria have an entirely different approach to energy production. Instead of using oxygen, they utilize electricity.
Researchers at Rice University have recently revealed the mechanism behind this unique process. In a publication in *Cell*, the scientists demonstrated that specific bacteria can produce energy by expelling electrons from their cells into surrounding materials. This process, termed extracellular respiration, enables the bacteria to thrive in environments where oxygen is limited, such as deep-sea vents or within the human digestive system.
These electricity-utilizing bacteria employ molecules known as naphthoquinones to export electrons from their cells. These molecules function as messengers, assisting the bacteria in performing the chemical reactions required to metabolize food and sustain themselves.
The researchers point out that while it has been known that bacteria can respire without oxygen for some time, this marks the first instance of understanding precisely how they accomplish this, making this an intriguing month for bacteria, especially given that scientists have recently identified new, unseen bacteria on China’s space station.
To validate their findings, the team conducted simulations and laboratory experiments. They demonstrated that bacteria placed on conductive surfaces could proliferate and persist in electricity generation even in the absence of oxygen. This validated that the bacteria can utilize surfaces to complete their energy cycle, analogous to our reliance on oxygen.
The identification of these electricity-utilizing bacteria may have significant implications. It could enhance technologies that depend on bacteria, such as wastewater management or clean energy systems. These bacteria could assist in rectifying chemical imbalances and ensuring systems operate more efficiently.
According to Ajo-Franklin, the results also propose new opportunities for leveraging bacteria in renewable energy, such as converting carbon dioxide into valuable products through the use of electricity. However, whether it can sustain that level of function remains to be seen in future studies.
