DIFFUSION IN BIOFILMS RESPIRING ON ELECTRODES

Rs Renslow; Jt Babauta; Pd Majors; H Beyenal

doi:10.1039/c2ee23394k

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DIFFUSION IN BIOFILMS RESPIRING ON ELECTRODES

Journal article

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DIFFUSION IN BIOFILMS RESPIRING ON ELECTRODES

Rs Renslow, Jt Babauta, Pd Majors and H Beyenal

Energy & environmental science, Vol.6(2), pp.595-607

2013

DOI: https://doi.org/10.1039/c2ee23394k

Handle:

https://hdl.handle.net/2376/109548

PMCID: PMC3571104

PMID: 23420623

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Abstract

diffusion

magnetic resonance

modeling

electron transfer

biofilm

diffusivity

Geobacter

Shewanella

diffusion coefficient

electrochemically active

The goal of this study was to measure spatially and temporally resolved effective diffusion coefficients (D(e)) in biofilms respiring on electrodes. Two model electrochemically active biofilms, Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1, were investigated. A novel nuclear magnetic resonance microimaging perfusion probe capable of simultaneous electrochemical and pulsed-field gradient nuclear magnetic resonance (PFG-NMR) techniques was used. PFG-NMR allowed noninvasive, nondestructive, high spatial resolution in situ D(e) measurements in living biofilms respiring on electrodes. The electrodes were polarized so that they would act as the sole terminal electron acceptor for microbial metabolism. We present our results as both two-dimensional D(e) heat maps and surface-averaged relative effective diffusion coefficient (D(rs)) depth profiles. We found that 1) D(rs) decreases with depth in G. sulfurreducens biofilms, following a sigmoid shape; 2) D(rs) at a given location decreases with G. sulfurreducens biofilm age; 3) average D(e) and D(rs) profiles in G. sulfurreducens biofilms are lower than those in S. oneidensis biofilms-the G. sulfurreducens biofilms studied here were on average 10 times denser than the S. oneidensis biofilms; and 4) halting the respiration of a G. sulfurreducens biofilm decreases the D(e) values. Density, reflected by D(e), plays a major role in the extracellular electron transfer strategies of electrochemically active biofilms.

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Title: DIFFUSION IN BIOFILMS RESPIRING ON ELECTRODES
Creators: Rs Renslow - The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA
Jt Babauta
Pd Majors
H Beyenal
Publication Details: Energy & environmental science, Vol.6(2), pp.595-607
Academic Unit: Chemical Engineering and Bioengineering, School of
Publisher: England
Grant note: T32 GM008336 / NIGMS NIH HHS
Identifiers: 99900547361001842
Language: English
Resource Type: Journal article