A newly identified soil bacterium may help unlock cleaner ways to recycle carbon dioxide and produce valuable chemicals using electricity. In a recent study, researchers report that the sulfate reducing bacterium Fundidesulfovibrio terrae possesses an unusual ability to both export and absorb electrical energy while converting carbon dioxide into acetate, an industrially important organic compound. The findings reveal a previously unknown microbial strategy that could support future carbon neutral technologies and sustainable chemical production.
The research team isolated the microorganism from paddy soil and discovered that it can perform bidirectional extracellular electron transfer, meaning it can move electrons out of and into its cells. Most organisms generate energy through internal chemical reactions, but some microbes have evolved the capacity to interact electrically with their environment. This ability allows them to exchange electrons with solid materials such as minerals or electrodes, helping them survive in oxygen limited environments and influencing global biogeochemical cycles.
In laboratory experiments, the researchers found that F. terrae can directly transfer electrons to iron minerals, reducing iron compounds without requiring chemical mediators. The bacterium achieved a reduction efficiency exceeding sixty percent, demonstrating its strong respiratory flexibility. Electrochemical measurements further confirmed that the microorganism can both donate electrons to electrodes and accept electrons from them, forming stable biofilms that support continuous electrical interaction with solid surfaces.
"This microorganism demonstrates an exceptional ability to harvest energy directly from electrical sources and channel it into carbon metabolism," said the study's corresponding author. "Its metabolic flexibility provides a new biological platform for linking renewable electricity with carbon recycling."
One of the most striking discoveries was the bacterium's ability to use electricity to drive carbon fixation. When supplied with electrons from an electrode and carbon dioxide as the only carbon source, F. terrae converted the greenhouse gas into acetate through the Wood Ljungdahl pathway, a highly efficient microbial carbon fixation mechanism. The system produced acetate concentrations exceeding 11 millimolar, demonstrating effective conversion of electrical energy into valuable organic products.
Genomic and biochemical analyses revealed that specialized proteins known as c type cytochromes play a critical role in enabling this electrical communication. These proteins act as molecular conduits that transport electrons across cell membranes. The bacterium also appears to use conductive pili structures that function similarly to microscopic wires, allowing efficient electron flow between cells and external surfaces.
The discovery expands scientific understanding of sulfate reducing bacteria, which are widely recognized for their roles in sulfur cycling, corrosion processes, and environmental remediation. Until now, only a limited number of microorganisms were known to perform bidirectional electron transfer. The newly identified mechanism suggests that these bacteria may play broader roles in natural ecosystems and engineered bioelectrochemical systems than previously recognized.
Beyond advancing microbial ecology, the findings hold promise for sustainable energy applications. Microbial electrosynthesis systems, which use microbes to convert electricity and carbon dioxide into fuels or chemicals, are gaining attention as potential tools for reducing greenhouse gas emissions. By demonstrating efficient carbon conversion driven by electrical energy, F. terrae provides a potential new biological resource for developing environmentally friendly manufacturing technologies.
The researchers emphasize that further studies are needed to optimize microbial electrosynthesis performance and to understand how such organisms function in natural and engineered environments. However, the discovery highlights the growing potential of electroactive microorganisms as bridges between renewable energy and carbon recycling.
As global efforts intensify to address climate change, harnessing microbes capable of transforming waste carbon into useful products may offer an innovative and sustainable pathway toward a low carbon future.
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Journal reference: Wang J, Huang J, Tang R, Lai Y, Mahmoud M, et al. 2026. Bidirectional extracellular electron transfer and electroautotrophic metabolism in Fundidesulfovibrio terrae. Energy & Environment Nexus 2: e006 doi: 10.48130/een-0025-0021
https://www.maxapress.com/article/doi/10.48130/een-0025-0021
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About Energy & Environment Nexus :
Energy & Environment Nexus (e-ISSN 3070-0582) is an open-access journal publishing high-quality research on the interplay between energy systems and environmental sustainability, including renewable energy, carbon mitigation, and green technologies.
