Cornell Researchers Discover Protein Condensates Facilitate Extracellular Electron Transfer in Bacteria

The findings could have applications in biotechnologies like microbial energy conversion.

Published on Feb. 24, 2026

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Cornell researchers have discovered that in electroactive bacteria, a group of CymA proteins in the inner membrane organize into a biomolecular condensate to facilitate the transfer of electrons across the cell envelope and into the extracellular environment. The researchers were able to manipulate this protein condensate formation by applying an electrochemical signal to the bacteria, demonstrating for the first time that electrical signals can drive changes in the spatial pattern of these proteins.

Why it matters

Understanding how electroactive bacteria transport electrons outside their cells is crucial for developing biotechnologies that rely on microbial electron transfer, such as microbial energy conversion. The discovery of CymA protein condensates as a key mechanism for this process provides new insights that could lead to advancements in these applications.

The details

The researchers used photoelectrochemistry-fluorescence microscopy to determine that during extracellular electron transfer, CymA proteins in the inner membrane of Shewanella oneidensis, a well-studied electroactive bacterium, reorganize into a confined region and drive their electron-transfer partners to do the same in the periplasmic space. This type of biomolecular condensate formation had not been previously observed in electroactive bacteria, though it is a known phenomenon in other cellular processes. By applying an electrochemical signal to the bacteria, the researchers were able to induce the formation of the CymA condensate and quantify the spatiotemporal dynamics of the protein reorganization.

  • The findings were published on February 17, 2026 in Nature Communications.

The players

Peng Chen

The Peter J.W. Debye Professor of Chemistry in the College of Arts and Sciences at Cornell University and the lead researcher on the project.

Youngchan Park

A former postdoctoral researcher at Cornell University who is now an assistant professor at Indiana University and the lead author on the study.

Buz Barstow

An assistant professor of biological and environmental engineering in the College of Agriculture and Life Sciences at Cornell University and a co-author on the study.

Shewanella oneidensis

A Gram-negative bacterium that is the most well-known and extensively studied microbe used for extracellular electron transport.

CymA

A protein in the inner membrane of electroactive bacteria that plays a key role in facilitating extracellular electron transfer.

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What they’re saying

“Electrons have to go through the cell envelope: the inner membrane, outer membrane and the periplasmic space. Now, electron transfer in biology, of course, doesn't just go through solutions. Electrons do not swim through water. Otherwise, they would get short-circuited.”

— Peng Chen, Peter J.W. Debye Professor of Chemistry (Cornell University)

“Many people have applied electrical signals to bacteria, but we discovered that by applying an electrochemical signal to the cell, it can change the spatial pattern of the protein. The pattern initially is homogeneous, and then you condense it. The electrical signal - basically, the electron transfer - will drive the change of a spatial pattern. That's a new thing.”

— Peng Chen, Peter J.W. Debye Professor of Chemistry (Cornell University)

What’s next

The researchers plan to further investigate how the spatial organization of CymA proteins and their electron transfer partners can be manipulated using electrochemical signals, with the goal of developing applications in biotechnologies such as microbial energy conversion.

The takeaway

The discovery of CymA protein condensates as a key mechanism for extracellular electron transfer in electroactive bacteria provides new insights that could lead to advancements in biotechnologies relying on microbial electron transport, such as microbial energy conversion.