Mercury methylation coupled to iron reduction by dissimilatory iron-reducing bacteria

Iron reduction and mercury methylation by dissimilatory iron-reducing bacteria (DIRB), Geobacter sulfurreducens and Shewanella oneidensis, were studied, and the relationship of mercury methylation coupled to iron reduction was determined. The ability of both bacteria for reducing iron was tested, an...

Full description

Saved in:
Bibliographic Details
Published in:Chemosphere (Oxford) 2015-03, Vol.122, p.206-212
Main Authors: Si, Youbin, Zou, Yan, Liu, Xiaohong, Si, Xiongyuan, Mao, Jingdong
Format: Article
Language:English
Subjects:
Bacteria
Ferric oxyhydroxide
Geobacter - metabolism
Geobacter sulfurreducens
Iron
Iron - metabolism
Joining
Mercuric Chloride - metabolism
Mercury (metal)
Mercury - metabolism
Methylation
Methylmercury Compounds - metabolism
Oxidation-Reduction
Reduction
Shewanella - metabolism
Shewanella oneidensis
Terminals
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Iron reduction and mercury methylation by dissimilatory iron-reducing bacteria (DIRB), Geobacter sulfurreducens and Shewanella oneidensis, were studied, and the relationship of mercury methylation coupled to iron reduction was determined. The ability of both bacteria for reducing iron was tested, and Fe(III) reduction occurred with the highest rate when ferric oxyhydroxide was used as a terminal electron acceptor. G. sulfurreducens had proven to mediate the production of methylmercury (MeHg), and a notable increase of MeHg following the addition of inorganic Hg was observed. When the initial concentration of HgCl2 was 500nM, about 177.03nM of MeHg was determined at 8d after G. sulfurreducens inoculation. S. oneidensis was tested negligible for Hg methylation and only 12.06nM of MeHg was determined. Iron reduction could potentially influence Hg methylation rates. The increase in MeHg was consistent with high rate of iron reduction, indicating that Fe(III) reduction stimulated the formation of MeHg. Furthermore, the net MeHg concentration increased at low Fe(III) additions from 1.78 to 3.57mM, and then decreased when the added Fe(III) was high from 7.14 to 17.85mM. The mercury methylation rate was suppressed with high Fe(III) additions, which might have been attributable to mercury complexation and low availability.
ISSN:0045-6535
1879-1298
DOI:10.1016/j.chemosphere.2014.11.054