Oregon State University (OSU) researchers have discovered an electrically conductive organism capable of carrying electrical currents similar to wires in a circuit. Since then, it has been named Ca. Electrothrix yaqonensis, in honor of the Native Americans of the region where it was discovered.
These electrically conductive bacteria could be critical in developing bioelectronics and biomaterials. According to the research team behind the discovery, such devices could usher in a new era for several industries where these often-disparate systems intersect, including medicine, food safety, and environmental monitoring and cleanup.
Electrically Conductive Organism and Bacteria Science
Bioelectronics was born in the 18th century when Italian physician-scientist Luigi Galvani used an electric current to make two detached frog legs jump. Since then, applications like blood glucose monitors and pacemakers have begun to blur the lines between technology and biology.
Previously, The Debrief has covered several efforts to merge the two worlds, including using brain-machine interfaces to predict mouse movements, granting people in wheelchairs the ability to navigate a crowded room, allowing others to move a robotic arm with their thoughts and to feed themselves, letting users play video games using only their mind, or even fly a virtual drone.
Like the OSU team that discovered the new electrically conductive organisms, several other efforts are underway to engineer bacteria for technological applications. These efforts include engineering bacteria to eat microplastics, create carbon-neutral biofuel, or create a key ingredient in the manufacture of rocket fuel.
Still, several industries operate at the junction of technology and biology and need devices that can function in challenging environments and under extreme conditions. Finding a bacteria that can conduct electricity like a metal circuit could be a key step toward a new generation of bioelectronics.
Unique Structure Gives Cable Bacteria Conductive Properties
In a published study, co-author Cheng Li, a postdoctoral researcher at Oregon State University at the time of the research, and Clare Reimers, distinguished professor emerita in the OSU College of Earth, Ocean, and Atmospheric Sciences, detail the discovery and identification of the new species from intertidal sediment samples collected at the Yaquina Bay estuary.
According to a statement from the research team, the newly discovered organism is a ‘cable’ bacteria, which “consist of rod-shaped cells attached end to end with a shared outer membrane, forming filaments that can reach several centimeters in length.” The team notes that electrically conductive bacteria are extremely rare and likely evolve the ability to “optimize their metabolic processes” to prosper in sediment environments.
After returning the samples to the lab, a genetic analysis showed a mix of genes and shared metabolic pathways of the CA. Electrothrix genus and the Ca. Electronema genus. The latter is the only known “cable” bacteria besides the newly discovered electrically conductive organism, which the researchers deemed significant.
“This new species seems to be a bridge, an early branch within the Ca. Electrothrix clade,” said Li, “which suggests it could provide new insights into how these bacteria evolved and how they might function in different environments.”
A closer analysis of the samples showed that the new organism possesses several structural features that facilitate its conductivity. These include surface ridges up to three times wider than those found in similar species.
These ridges house highly conductive fibers of unique, “nickel-based” molecules. When an electrical current is applied, the fibers transport the current over long distances just like a wire. Li says a design that includes highly conductive nickel protein “can inspire new bioelectronics.”
Bacteria Could Help Clean the Environment
In their native environment, Li said that these bacteria move electrons through the soil, “connecting electron acceptors like oxygen or nitrate at the sediment surface with donors like sulfide in deeper sediment layers.” Participating in these reduction-oxidation reactions means these bacteria use this unique capability to affect their surrounding sediment geochemistry by altering nutrient cycling.
Along with implantable devices and other sci-fi-type applications, scientists could customize this ability to clean the environment, including areas polluted with toxic substances.
“These bacteria can transfer electrons to clean up pollutants, so they could be used to remove harmful substances from sediments,” Li said.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.