Physical Sciences
Research Highlights

June 2011

New Research Details Structure of First Component in an Electricity-conducting Bacterial Wire

Architectural insights of proteins that make up the wires might help researchers immobilize metal contaminants or engineer bio-inspired fuel cells

Shewanella oneidensis uses an electron-shuttling conduit made up of proteins to live off of metal in minerals such as this hematite. Enlarge Image

Results: Bacteria called Shewanella can use metal ions in place of oxygen to live and grow. In the process, Shewanella can transform some metals and trap them in minerals, a useful skill for engineers who want to stop radioactive or toxic metals from migrating in soil or groundwater. The bacteria also help cycle metals used as nutrients through the biosphere.

But bacteria can't inhale solid metal like humans breathe oxygen. Instead of lungs, Shewanella send out tiny wires that contact metals and minerals. Within these wires are proteins that pass electrons outward, but no one knows what these proteins look like or how exactly they work together in a large complex. Now, a collaborative research team from the University of East Anglia and Pacific Northwest National Laboratory have determined the structure of the first of these protein components, providing insights into how bacteria live off minerals and rocks.

For more information, see the PNNL news release.