Get access

A Laminar-Flow Microfluidic Device for Quantitative Analysis of Microbial Electrochemical Activity

Authors

  • Dr. Zhongjian Li,

    1. Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, NY 14853 (USA), Fax: (+1) 607-255-4449
    Search for more papers by this author
    • These authors contributed equally to this work.

  • Dr. Arvind Venkataraman,

    1. Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, NY 14853 (USA), Fax: (+1) 607-255-4449
    Search for more papers by this author
    • These authors contributed equally to this work.

  • Prof. Dr. Miriam A. Rosenbaum ,

    1. Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, NY 14853 (USA), Fax: (+1) 607-255-4449
    2. Current address: Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
    Search for more papers by this author
  • Prof. Dr. Largus T. Angenent

    Corresponding author
    1. Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, NY 14853 (USA), Fax: (+1) 607-255-4449
    • Department of Biological and Environmental Engineering, Cornell University, 214 Riley-Robb Hall, Ithaca, NY 14853 (USA), Fax: (+1) 607-255-4449
    Search for more papers by this author

Abstract

We report a laminar flow-based microfluidic bioelectrochemical system (BES) that was fabricated by using polydimethyl siloxane (PDMS) channels and gold electrodes. The microfluidic BES was operated as a potentiostatically controlled two-electrode system. A pure culture of Geobacter sulfurreducens strain PCA, which is a model electrode-respiring bacterium, was grown in the channel and respired with the electrode under strict anaerobic conditions. We took advantage of the short hydraulic retention time (≈2 min) and response times (<21 min) to rapidly test the effect of certain chemical stimuli, such as O2 and anthraquinone disulfide (AQDS), on electric current production by G. sulfurreducens. The results showed that: i) short-term (2 min) exposure to O2-saturated solution did not cause any irreversible toxicity to G. sulfurreducens, and ii) AQDS can be used as a redox mediator by G. sulfurreducens for shuttling electrons between the microbe and the electrode. We, therefore, demonstrate that the microfluidic BES is a promising research tool for gaining insight into microbial electrochemical activity. In our two-dimensional microfluidic-based research tool, a well-defined electrochemical environment can be maintained with the help of laminar flow without a membrane to separate two electrodes.

Ancillary