Reductive precipitation of the nuclear fuel cycle contaminant Tc(VII) by Geobacter sulfurreducens

Joanna Renshaw, J. R. Lloyd, F. R. Livens, Iain May, M. V. Coppi, D. R. Lovley, S. Glasauer

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

Abstract

echnetium is a key radioactive pollutant in subsurface environments contaminated with radioactive waste. However, dissimilatory Fe(III)-reducing bacteria can control its mobility through the enzymatic reduction and precipitation of soluble Tc(VII) to insoluble Tc(IV). We have investigated the mechanism of electron transfer to Tc(VII) in the model dissimilatory Fe(III)-reducing bacterium Geobacter sulfurreducens. Reduction of Tc(VII) by G. sulfurreducens required hydrogen as the electron donor, suggesting the involvement of a hydrogenase, while CO profiling indicated that Ni and Fe are the metal cofactors. Enzymatic activity and the reduced Tc(IV) precipitate was localized in the periplasm using Cu(II) (a selective inhibitor for periplasmic hydrogenases) and transmission electron microscopy. Finally, a deletion mutant unable to synthesize the primary periplasmic NiFe hydrogenase of G. sulfurreducens was unable to reduce Tc(VII), confirming a role for this protein in electron transfer to the fission product.
Original languageEnglish
Title of host publicationEuropean Symposium on Environmental Biotechnology, ESEB 2004
Subtitle of host publicationProceedings of the European Symposium on Environmental Biotechnology, 25-28 April 2004, Oostende, Belgium
EditorsW. Verstraete
Place of PublicationNetherlands
Pages251-254
Number of pages4
Publication statusPublished - 2005
EventEuropean Symposium on Environmental Biotechnology - Oostende, Belgium
Duration: 25 Apr 200428 Apr 2004

Conference

ConferenceEuropean Symposium on Environmental Biotechnology
CountryBelgium
CityOostende
Period25/04/0428/04/04

Keywords

  • reductive precipitation
  • nuclear fuel cycle
  • contaminant
  • Tc(VII)
  • geobacter sulfurreducens

Projects

Mechanisms for the reduction of actinides and Tc(VII) in Geobacter sulfurreducens

Lloyd, J. R., Renshaw, J., Livens, F. R. & May, I.

1/01/0330/11/05

Project: Projects from Previous Employment

Cite this

Renshaw, J., Lloyd, J. R., Livens, F. R., May, I., Coppi, M. V., Lovley, D. R., & Glasauer, S. (2005). Reductive precipitation of the nuclear fuel cycle contaminant Tc(VII) by Geobacter sulfurreducens. In W. Verstraete (Ed.), European Symposium on Environmental Biotechnology, ESEB 2004: Proceedings of the European Symposium on Environmental Biotechnology, 25-28 April 2004, Oostende, Belgium (pp. 251-254).