Journal article
In situ effective diffusion coefficient profiles in live biofilms using pulsed-field gradient nuclear magnetic resonance
Biotechnology and bioengineering, Vol.106(6), pp.928-937
08/15/2010
Handle:
https://hdl.handle.net/2376/101585
PMCID: PMC2898744
PMID: 20589671
Abstract
Diffusive mass transfer in biofilms is characterized by the effective diffusion coefficient. It is well-documented that the effective diffusion coefficient can vary by location in a biofilm. The current literature is dominated by effective diffusion coefficient measurements for distinct cell clusters and stratified biofilms showing this spatial variation. Regardless of whether distinct cell clusters or surface-averaging methods are used, position-dependent measurements of the effective diffusion coefficient are currently: 1) invasive to the biofilm, 2) performed under unnatural conditions, 3) lethal to cells, and/or 4) spatially restricted to only certain regions of the biofilm. Invasive measurements can lead to inaccurate results and prohibit further (time-dependent) measurements which are important for the mathematical modeling of biofilms. In this study our goals were to: 1) measure the effective diffusion coefficient for water in live biofilms, 2) monitor how the effective diffusion coefficient changes over time under growth conditions, and 3) correlate the effective diffusion coefficient with depth in the biofilm. We measured
in situ
two-dimensional effective diffusion coefficient maps within
Shewanella oneidensis
MR-1 biofilms using pulsed-field gradient nuclear magnetic resonance methods, and used them to calculate surface-averaged relative effective diffusion coefficient (D
rs
) profiles. We found that 1) D
rs
decreased from the top of the biofilm to the bottom, 2) D
rs
profiles differed for biofilms of different ages, 3) D
rs
profiles changed over time and generally decreased with time, 4) all the biofilms showed very similar D
rs
profiles near the top of the biofilm, and 5) the D
rs
profile near the bottom of the biofilm was different for each biofilm. Practically, our results demonstrate that advanced biofilm models should use a variable effective diffusivity which changes with time and location in the biofilm.
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Details
- Title
- In situ effective diffusion coefficient profiles in live biofilms using pulsed-field gradient nuclear magnetic resonance
- Creators
- Ryan S Renslow - The Gene and Linda Voiland School of Chemical Engineering and Bioengineering and the Center for Environmental, Sediment and Aquatic Research (CESAR), Washington State University, Pullman, WA, United States of AmericaPaul D Majors - Pacific Northwest National Laboratory, Richland, WA, United States of AmericaJeffrey S McLean - J. Craig Venter Institute, San Diego, CA, United States of AmericaJim K Fredrickson - Pacific Northwest National Laboratory, Richland, WA, United States of AmericaBulbul Ahmed - The Gene and Linda Voiland School of Chemical Engineering and Bioengineering and the Center for Environmental, Sediment and Aquatic Research (CESAR), Washington State University, Pullman, WA, United States of AmericaHaluk Beyenal - The Gene and Linda Voiland School of Chemical Engineering and Bioengineering and the Center for Environmental, Sediment and Aquatic Research (CESAR), Washington State University, Pullman, WA, United States of America
- Publication Details
- Biotechnology and bioengineering, Vol.106(6), pp.928-937
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Identifiers
- 99900546559801842
- Language
- English
- Resource Type
- Journal article