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
May 31, 2011
RICHLAND, Wash. –
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.
In addition to cleaning up legacy radioactive waste, the information will help researchers tap bacteria to generate currents in fuel cells or for applications in synthetic biology. Researchers performed some of the work, which they reported in the Proceedings of the National Academy of Sciences' Early Edition, using instruments and expertise at EMSL, the Department of Energy's Environmental Molecular Sciences Laboratory on the PNNL campus.
Read the entire release from the University of East Anglia here.
Reference: Thomas A. Clarke, Marcus J. Edwards, Andrew J. Gates, Andrea Hall, Gaye F. White, Justin Bradley, Catherine Reardon, Liang Shi, Alexander S. Beliaev, Matthew J. Marshall, Zheming Wang, Nicholas J. Watmough, James Fredrickson, John Zachara, Julea N. Butt, and David J. Richardson, Structure of a bacterial cell surface decaheme electron conduit. Proc Natl Acad Sci U S A, Early Edition online the week of May 23-28, 2011. DOI 10.1073/pnas.1017200108, (http://www.pnas.org/content/early/2011/05/16/1017200108).
Tags: Environment, Fundamental Science, Environmental Remediation, Molecular Biology and Biochemistry