Applied Microbiology and Biotechnology

, Volume 96, Issue 3, pp 841–849

Prolongation of electrode lifetime in biofuel cells by periodic enzyme renewal

  • S. Rubenwolf
  • S. Sané
  • L. Hussein
  • J. Kestel
  • F. von Stetten
  • G. Urban
  • M. Krueger
  • R. Zengerle
  • S. Kerzenmacher
Bioenergy and Biofuels

DOI: 10.1007/s00253-012-4374-8

Cite this article as:
Rubenwolf, S., Sané, S., Hussein, L. et al. Appl Microbiol Biotechnol (2012) 96: 841. doi:10.1007/s00253-012-4374-8

Abstract

Enzymatically catalyzed biofuel cells show unique specificity and promise high power densities, but suffer from a limited lifetime due to enzyme deactivation. In the present work, we demonstrate a novel concept to extend the lifetime of a laccase-catalyzed oxygen reduction cathode in which we decouple the electrode lifetime from the limited enzyme lifetime by a regular resupply of fresh enzymes. Thereto, the adsorption behavior of laccase from Trametes versicolor to buckypaper electrode material, as well as its time-dependent deactivation characteristics, has been investigated. Laccase shows a Langmuir-type adsorption to the carbon nanotube-based buckypaper electrodes, with a mean residence time of 2 days per molecule. In a citrate buffer of pH 5, laccase does not show any deactivation at room temperature for 2 days and exhibits a half-life of 9 days. In a long-term experiment, the laccase electrodes were operated at a constant galvanostatic load. The laccase-containing catholyte was periodically exchanged against a freshly prepared one every second day to provide sufficient active enzymes in the catholyte for the replacement of desorbed inactive enzymes. Compared to a corresponding control experiment without catholyte exchange, this procedure resulted in a 2.5 times longer cathode lifetime of 19 ± 9 days in which the electrode showed a potential above 0.744 V vs. normal hydrogen electrode at 110 μA cm−2. This clearly indicates the successful exchange of molecules by desorption and re-adsorption and is a first step toward the realization of a self-regenerating enzymatic biofuel cell in which enzyme-producing microorganisms are integrated into the electrode to continuously resupply fresh enzymes.

Keywords

Enzymatic biofuel cellLaccaseLifetimeLong-term stabilityAdsorptionBuckypaper

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • S. Rubenwolf
    • 1
  • S. Sané
    • 1
  • L. Hussein
    • 2
    • 3
  • J. Kestel
    • 1
    • 5
  • F. von Stetten
    • 1
  • G. Urban
    • 2
    • 3
  • M. Krueger
    • 2
    • 3
  • R. Zengerle
    • 1
    • 4
  • S. Kerzenmacher
    • 1
  1. 1.Laboratory for MEMS Applications, Department of Microsystems Engineering—IMTEKUniversity of FreiburgFreiburgGermany
  2. 2.Freiburg Materials Research Centre (FMF)University of FreiburgFreiburgGermany
  3. 3.Laboratory for Sensors, Department of Microsystems Engineering—IMTEKUniversity of FreiburgFreiburgGermany
  4. 4.BIOSS Centre for Biological Signalling StudiesUniversity of FreiburgFreiburgGermany
  5. 5.ifm electronic GmbHEssenGermany