Aerated Shewanella oneidensis in continuously fed bioelectrochemical systems for power and hydrogen production

Authors

  • Miriam Rosenbaum,

    1. Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, New York 14853; telephone: 607-255-2480; fax: 607-255-4080
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  • Michael A. Cotta,

    1. Fermentation Biotechnology Research Unit, United States Department of Agriculture, Agricultural Research Service (ARS), National Center for Agricultural Utilization Research (NCAUR), Peoria, Illinois
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  • Largus T. Angenent

    Corresponding author
    1. Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, New York 14853; telephone: 607-255-2480; fax: 607-255-4080
    • Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, New York 14853; telephone: 607-255-2480; fax: 607-255-4080.
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Abstract

We studied the effects of aeration of Shewanella oneidensis on potentiostatic current production, hydrogen production in a microbial electrolysis cell, and electric power generation in a microbial fuel cell (MFC). The potentiostatic performance of aerated S. oneidensis was considerably enhanced to a maximum current density of 0.45 A/m2 or 80.3 A/m3 (mean: 0.34 A/m2, 57.2 A/m3) compared to anaerobically grown cultures. Biocatalyzed hydrogen production rates with aerated S. oneidensis were studied within the applied potential range of 0.3–0.9 V and were highest at 0.9 V with 0.3 m3 H2/m3 day, which has been reported for mixed cultures, but is ∼10 times higher than reported for an anaerobic culture of S. oneidensis. Aerated MFC experiments produced a maximum power density of 3.56 W/m3 at a 200-Ω external resistor. The main reasons for enhanced electrochemical performance are higher levels of active biomass and more efficient substrate utilization under aerobic conditions. Coulombic efficiencies, however, were greatly reduced due to losses of reducing equivalents to aerobic respiration in the anode chamber. The next challenge will be to optimize the aeration rate of the bacterial culture to balance between maximization of bacterial activation and minimization of aerobic respiration in the culture. Biotechnol. Bioeng. 2010;105: 880–888. © 2009 Wiley Periodicals, Inc.

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