Metal ions enhanced extracellular electron transfer and current output generation by Shewanella oneidensis MR-1.

Aisha Alshahrani, Loyola University Chicago

Alanah Fitch and John Al-Bazi are the faculty sponsors of this poster.

Description

The goal in this study is enhancement efficiency of bacterial extracellular electron transfer (EET) in Shewanella. oneidensis MR-1 by addition of metal ions concentrations while controlling ionic strength for improving the current output of Microbial fuel cells. Shown here are electrochemical studies on effect of metal ions concentrations on S. oneidensis MR-1 attachment and growth at Indium tin oxide (ITO) electrode. Initial surface coverage of bacteria was measured with respect to four metrics. One metric is the observed lag time before currents increase during bacterial loading at the Indium tin oxide (ITO) electrode surface. A second one is the current associated with that lag time. The third is the maximum anodic loading current that occurs after the lag period. Finally, a cyclic voltammetric experiment following loading has a metric associated with the peak current. Our results clearly show a major difference in attachment and behavior of S. oneidensis MR-1 for CaCl 2 , PbCl 2 , CdCl 2 , and MgCl 2 compared to control. Our hypothesis confirmed the effects of the metal ions at controlled ionic strength are still significant. Electrochemical measurements indicated that the film attachment measured by maximum anodic loading currents was a successful measurement. The final coverage (as measured by cathodic peak charge in cyclic voltammetry, Qpc) increases with increasing metal ions concentrations. Also, surface cell aggregation by confocal microscope measurements. We found the cells attached to the electrode increasing more with the addition of metal ions concentrations based with the following metals in the order Ca 2+ > Pb 2+ > Cd 2+ > Mg 2+ compared to control . Metal ions affect on metabolic which tested by the riboflavin production and glucose consumption effect on current output.

 
Apr 19th, 11:00 AM

Metal ions enhanced extracellular electron transfer and current output generation by Shewanella oneidensis MR-1.

The goal in this study is enhancement efficiency of bacterial extracellular electron transfer (EET) in Shewanella. oneidensis MR-1 by addition of metal ions concentrations while controlling ionic strength for improving the current output of Microbial fuel cells. Shown here are electrochemical studies on effect of metal ions concentrations on S. oneidensis MR-1 attachment and growth at Indium tin oxide (ITO) electrode. Initial surface coverage of bacteria was measured with respect to four metrics. One metric is the observed lag time before currents increase during bacterial loading at the Indium tin oxide (ITO) electrode surface. A second one is the current associated with that lag time. The third is the maximum anodic loading current that occurs after the lag period. Finally, a cyclic voltammetric experiment following loading has a metric associated with the peak current. Our results clearly show a major difference in attachment and behavior of S. oneidensis MR-1 for CaCl 2 , PbCl 2 , CdCl 2 , and MgCl 2 compared to control. Our hypothesis confirmed the effects of the metal ions at controlled ionic strength are still significant. Electrochemical measurements indicated that the film attachment measured by maximum anodic loading currents was a successful measurement. The final coverage (as measured by cathodic peak charge in cyclic voltammetry, Qpc) increases with increasing metal ions concentrations. Also, surface cell aggregation by confocal microscope measurements. We found the cells attached to the electrode increasing more with the addition of metal ions concentrations based with the following metals in the order Ca 2+ > Pb 2+ > Cd 2+ > Mg 2+ compared to control . Metal ions affect on metabolic which tested by the riboflavin production and glucose consumption effect on current output.