University of Southern California Mork Family Department of Chemical Engineering and Materials Science The USC Andrew and Erna Viterbi School of Engineering USC
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Graduate Seminar




Living Conductors: The Nature and Implications of Electrical Transport in Bacterial Nanowires


 Mohammad El-Naggar
Professor, University of Southern California 
Abstract

Bacterial nanowires are conductive pilus-like appendages produced by bacteria, most notably some ‘metal-reducers’, in direct response to electron acceptor limitation. These recently discovered supramolecular assemblies represent a new paradigm in extracellular electron transfer, but the mechanism of electron transport remains unclear. This talk will feature quantitative measurements of transport across bacterial nanowires produced by the dissimilatory metal-reducing bacterium (DMRB) Shewanella oneidensis MR-1, whose electron transport system holds practical promise for renewable energy recovery and bioremediation. The Shewanella nanowires display a surprising non-linear electrical transport behavior, where the voltage dependence of the conductance reveals peaks indicating discrete energy levels with higher electronic density of states. These results indicate that the molecular constituents along the Shewanella nanowires possess an intricate electronic structure that plays a role in mediating the overall electron transport.  We will highlight the vast implications of signal transduction at the biological-inorganic interface as well as devices that exploit this interface, such as microbial fuel cells. We will also discuss our recent efforts to develop experimental and image analysis tools that target the interactions between the living and non-living worlds at this interface.

URL:

http://college.usc.edu/faculty/faculty1013055.html

Time and Location

12:45p.m. Tuesday, January 22, 2008
OHE 122

The Scientific Community is Cordially Invited.