Electricity-conducting cable bacteria form a group of multicellular prokaryotes that enable electron transfer over centimeter-scale distances within marine and freshwater sediments. Biologists have isolated and characterized a new cable bacteria species from an intertidal estuarine mudflat within Yaquina Bay in Oregon, the United States.
Microscopic investigation of the cable bacterium Ca. Electrothrix yaqonensis, strain YB6. Image credit: Hiralal et al., doi: 10.1128/aem.02502-24.
“Cable bacteria are a group of filamentous bacteria that perform electrogenic sulfide oxidation within the upper layers of aquatic sediments,” said Dr. Cheng Li, a postdoctoral researcher at Oregon State University, and colleagues.
“Their electrogenic metabolism involves a peculiar division of labor between cells in the multicellular filament: electrons are transferred from deeper sediment layers, where cells perform sulfide oxidation, to the surface, where other cells use oxygen or nitrate as the terminal electron acceptor.”
“This long-distance electron transport is facilitated by a specialized network of conductive periplasmic fibers, which are embedded within parallel-running ridges that span a filament from end-to-end.”
“These fibers are interconnected via a conductive cartwheel-shaped structure present at the cell-cell interfaces, thus providing redundancy to the electrical network.”
Named Ca. Electrothrix yaqonensis, the new cable bacterium species was collected from mudflats of Yaquina Bay, Oregon.
“This new species seems to be a bridge, an early branch within the Ca. Electrothrix clade, which suggests it could provide new insights into how these bacteria evolved and how they might function in different environments,” Dr. Li said.
“It stands out from all other described cable bacteria species in terms of its metabolic potential, and it has distinctive structural features, including pronounced surface ridges, up to three times wider than those seen in other species, that house highly conductive fibers made of unique, nickel-based molecules.”
“These bacteria can transfer electrons to clean up pollutants, so they could be used to remove harmful substances from sediments.”
“Also, their design of a highly conductive nickel protein can possibly inspire new bioelectronics.”
Ca. Electrothrix yaqonensis draws its name from the Yaqona people, whose ancestral lands encompassed Yaquina Bay.
“Naming an ecologically important bacterium after a Tribe recognizes its historical bond with the land and acknowledges its enduring contributions to ecological knowledge and sustainability,” Dr. Li said.
The team’s paper was published this week in the journal Applied and Environmental Microbiology.
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Anwar Hiralal et al. A novel cable bacteria species with a distinct morphology and genomic potential. Appl Environ Microbiol, published online April 22, 2025; doi: 10.1128/aem.02502-24
