Dataset Information

Investigation of Electron Transfer by Geobacter sulfurreducens Biofilms by using an Electrochemical Quartz Crystal Microbalance.

ABSTRACT: Both the short- and long-term electron-transfer processes of electrode-respiring Geobacter sulfurreducens biofilms are demonstrated by using an electrochemical quartz crystal microbalance (QCM). The QCM monitors the frequency shift from the initial resonant frequency (background) in real time, while the current increases, because of biofilm growth. In the short term, the frequency shift is linear with respect to current for the biofilm. In long-term biofilm growth up to the exponential phase, a second linear region of frequency shift with respect to current is observed. In addition to the frequency shift response at constant polarization, the frequency shift response is coupled to cyclic voltammetry experiments. During cyclic voltammetry, a reproducible, negative increase in frequency shift is observed at oxidizing potentials. The results suggest that a QCM can be used in applications in which it is useful to find the most efficient current producer.

SUBMITTER: Babauta JT

PROVIDER: S-EPMC4964883 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Investigation of Electron Transfer by <i>Geobacter sulfurreducens</i> Biofilms by using an Electrochemical Quartz Crystal Microbalance.

Babauta Jerome T JT Beasley Christopher A CA Beyenal Haluk H

ChemElectroChem 20140808 11

Both the short- and long-term electron-transfer processes of electrode-respiring <i>Geobacter sulfurreducens</i> biofilms are demonstrated by using an electrochemical quartz crystal microbalance (QCM). The QCM monitors the frequency shift from the initial resonant frequency (background) in real time, while the current increases, because of biofilm growth. In the short term, the frequency shift is linear with respect to current for the biofilm. In long-term biofilm growth up to the exponential ph ...[more]

PMID: 27525205

Similar Datasets

Project description:Multiheme cytochromes have been implicated in Geobacter sulfurreducens extracellular electron transfer (EET). These proteins are potential targets to improve EET and enhance bioremediation and electrical current production by G. sulfurreducens. However, the functional characterization of multiheme cytochromes is particularly complex due to the co-existence of several microstates in solution, connecting the fully reduced and fully oxidized states. Over the last decade, new strategies have been developed to characterize multiheme redox proteins functionally and structurally. These strategies were used to reveal the functional mechanism of G. sulfurreducens multiheme cytochromes and also to identify key residues in these proteins for EET. In previous studies, we set the foundations for enhancement of the EET abilities of G. sulfurreducens by characterizing a family of five triheme cytochromes (PpcA-E). These periplasmic cytochromes are implicated in electron transfer between the oxidative reactions of metabolism in the cytoplasm and the reduction of extracellular terminal electron acceptors at the cell's outer surface. The results obtained suggested that PpcA can couple e(-)/H(+) transfer, a property that might contribute to the proton electrochemical gradient across the cytoplasmic membrane for metabolic energy production. The structural and functional properties of PpcA were characterized in detail and used for rational design of a family of 23 single site PpcA mutants. In this review, we summarize the functional characterization of the native and mutant proteins. Mutants that retain the mechanistic features of PpcA and adopt preferential e(-)/H(+) transfer pathways at lower reduction potential values compared to the wild-type protein were selected for in vivo studies as the best candidates to increase the electron transfer rate of G. sulfurreducens. For the first time G. sulfurreducens strains have been manipulated by the introduction of mutant forms of essential proteins with the aim to develop and improve bioelectrochemical technologies.

Dataset Information

Investigation of Electron Transfer by Geobacter sulfurreducens Biofilms by using an Electrochemical Quartz Crystal Microbalance.

Publications

Investigation of Electron Transfer by <i>Geobacter sulfurreducens</i> Biofilms by using an Electrochemical Quartz Crystal Microbalance.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets