Electrical and Morphological Characterization of Monocultures and Co-Cultures of Shewanella Putrefaciens and Shewanella Oneidensis in a Microbial Fuel Cell
Authors:
Kirsten Larson, Michael ShawMentor:
Michael Shaw, Professor of Physics and Bioengineering, California Lutheran UniversityThe diminishing supply of fossil fuels has led to a global effort to develop novel renewable energy conversion strategies including microbial fuel cells (MFCs). MFCs operate by producing electricity via the breakdown of organic matter by living bacteria. The purpose of the present study was to design and commission an MFC and electrical characterization apparatus for the purpose of measuring and analyzing the electrical output of single cultures of the Shewanella Oneidensis and Shewanella Putrefaciens bacterial species, as well as the potential synergistic interactions of co-cultures of the two species. Here we present the design of a novel, low-cost and disposable MFC aimed at rapid screening of assays in MFC experiments. Furthermore, we found that co-cultures exhibited a steady-state open circuit voltage of 0.27V ± 0.02V, compared to 0.16V ± 0.04V for the monocultures, thus indicating potential synergistic interactions between the two species. Finally, high-magnification scanning electron micrographs of the bacteria morphologies are presented as confirmation of the presence of bacteria. We conclude that these results demonstrate the feasibility of co-cultured MFCs comprising Shewanella Oneidensis and Shewanella Putrefaciens bacteria for enhanced output voltage.