Wang, Y, Yu, Q, Mishra, B et al. (3 more authors) (2018) Adsorption of Methylmercury onto Geobacter bemidijensis Bem. Environmental Science and Technology, 52 (20). pp. 11564-11572. ISSN 0013-936X
Abstract
The anaerobic bacterium Geobacter bemidijensis Bem has the unique ability to both produce and degrade methylmercury (MeHg). While the adsorption of MeHg onto bacterial surfaces can affect the release of MeHg into aquatic environments as well as the uptake of MeHg for demethylation, the binding of MeHg to the bacterial envelope remains poorly understood. In this study, we quantified the adsorption of MeHg onto G. bemidijensis and applied X-ray absorption spectroscopy (XAS) to elucidate the mechanism of MeHg binding. The results showed MeHg adsorption onto G. bemidijensis cell surfaces was rapid and occurred via complexation to sulfhydryl functional groups. Titration experiments yielded cell surface sulfhydryl concentrations of 3.8 ± 0.2 μmol/g (wet cells). A one-site adsorption model with MeHg binding onto sulfhydryl sites provided excellent fits to adsorption isotherms conducted at different cell densities. The log K binding constant of MeHg onto the sulfhydryl sites was determined to be 10.5 ± 0.4. These findings provide a quantitative framework to describe MeHg binding onto bacterial cell surfaces and elucidate the importance of bacterial cells as possible carriers of adsorbed MeHg in natural aquatic systems.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | Copyright © 2018 American Chemical Society. This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Environmental Science & Technology after peer review. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 23 Nov 2018 15:34 |
Last Modified: | 12 Sep 2019 00:38 |
Status: | Published |
Publisher: | ACS |
Identification Number: | 10.1021/acs.est.8b01987 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:137783 |