Journal article
Contribution of Extracellular Polymeric Substances from Shewanella sp. HRCR-1 Biofilms to U(VI) Immobilization
Environmental science & technology, Vol.45(13), pp.5483-5490
07/01/2011
Handle:
https://hdl.handle.net/2376/100412
PMID: 21627155
Abstract
The goal of this study was to quantify the contribution of extracellular polymeric substances (EPS) to U(VI) immobilization by Shewanella sp. HRCR-1. Through comparison of U(VI) immobilization using cells with bound EPS (bEPS) and cells with minimal EPS, we show that (i) bEPS from Shewanella sp. HRCR-1 biofilms contribute significantly to U(VI) immobilization, especially at low initial U(VI) concentrations, through both sorption and reduction; (ii) bEPS can be considered a functional extension of the cells for U(VI) immobilization and they likely play more important roles at lower initial U(VI) concentrations; and (iii) the U(VI) reduction efficiency is dependent upon the initial U(VI) concentration and decreases at lower concentrations. To quantify the relative contributions of sorption and reduction to U(VI) immobilization by EPS fractions, we isolated loosely associated EPS (laEPS) and bEPS from Shewanella sp. HRCR-1 biofilms grown in a hollow fiber membrane biofilm reactor and tested their reactivity with U(VI). We found that, when reduced, the isolated cell-free EPS fractions could reduce U(VI). Polysaccharides in the EPS likely contributed to U(VI) sorption and dominated the reactivity of laEPS, while redox active components (e.g., outer membrane c-type cytochromes), especially in bEPS, possibly facilitated U(VI) reduction.
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Details
- Title
- Contribution of Extracellular Polymeric Substances from Shewanella sp. HRCR-1 Biofilms to U(VI) Immobilization
- Creators
- Bin CaoBulbul AhmedDavid W KennedyZheming WangLiang ShiMatthew J MarshallJim K FredricksonNancy G IsernPaul D MajorsHaluk Beyenal
- Publication Details
- Environmental science & technology, Vol.45(13), pp.5483-5490
- Academic Unit
- Chemistry, Department of; Chemical Engineering and Bioengineering, School of
- Publisher
- American Chemical Society
- Identifiers
- 99900546666201842
- Language
- English
- Resource Type
- Journal article