(257e) Metabolic Flux Analysis of Shewanella Oneidensis MR-1 Producing Electricity in a Microbial Fuel Cell

Microbial fuel cells (MFCs) are bioelectrochemical systems in which microbes catalyze the production of electricity from the oxidation of organic substrates.  In addition to having several applications, including wastewater treatment, MFCs present an interesting metabolic system: microbes convert chemical energy to external electrical energy by utilizing a solid electrode as the terminal electron acceptor.  We have employed ¹³C metabolic flux analysis, in which isotopically-labeled tracers are applied to elucidate fluxes, to investigate the metabolism of a microbe within an MFC.  Shewanella oneidensis MR-1 was selected as the model organism because it is known to be electroactive and its metabolic network has been previously described.  We present the fluxes through gluconeogenesis, the TCA cycle, the pentose phosphate pathway, and serine metabolism for S. oneidensis MR-1 in an MFC and compare them with the fluxes in systems utilizing other terminal electron acceptors.  These results provide insight into engineering microbes for electricity production in MFCs.