ATR-SEIRAs characterization of surface redox processes in G. sulfurreducens

Authors
Busalmen, Juan Pablo; Esteve-Nuñez, Abraham; Berná, Antonio; Feliu, Juan Miguel
Publication Year
2009
Language
English
Format
article
Status
Published version
Description
In this work we report on the occurrence of at least two different redox pairs on the cell surface of the electrogenic bacteria Geobacter sulfurreducens adsorbed on gold that are expressed in response to the polarization potential. As previously reported on graphite (Environ. Sci. Technol. 42 (2008) 2445) a typical low potential redox pair is found centered at around − 0.06 V when cells are polarized for a few hours at 0.2 V, while a new pair centered at around 0.38 V is expressed upon polarization at 0.6 V. Reversible changes in the IR band pattern of whole cells where obtained by Attenuated Total Reflection-Surface Enhanced Infrared Absorption Spectroscopy (ATR-SEIRAS) upon potential cycling around both redox pairs. Changes clearly resemble the electrochemical turnover of oxidized/reduced states in c-type cytochromes, thus evidencing the nature of the involved molecules. The expression of external cytochromes in response to the potential of the electron acceptor suggests the existence of alternative pathways of electron transport with different energy yield, though it remains to be demonstrated.
Fil: Busalmen, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Universidad de Alicante; España
Fil: Esteve-Nuñez, Abraham. Centro de Astrobiología; España
Fil: Berná, Antonio. Universidad de Alicante; España
Fil: Feliu, Juan Miguel. Universidad de Alicante; España
Subject
ELECTRODE-REDUCING BACTERIA
ELECTRON TRANSPORT MECHANISM
CYTOCHROMES
Físico-Química, Ciencia de los Polímeros, Electroquímica
Ciencias Químicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/13242