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

Graduate SeminarbyProfessor Mohammad El-NaggarUniversity of Southern California
Los Angeles, CAAbstract: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.Tuesday, January 22, 2008
Seminar at 12:45p.m.
OHE 122
The Scientific Community is Cordially Invited.

Location: Olin Hall of Engineering (OHE) - 122

Audiences: Everyone Is Invited

Contact: Petra Pearce Sapir