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Published on: December 19, 2017
Mercury methylation by dissimilatory iron-reducing bacteria.
E J Kerin1, C C Gilmour, E Roden
1University of Maryland, Chesapeake Biological Laboratory, Solomons, MD, USA.
Applied and Environmental Microbiology
|October 24, 2006
Summary
Certain iron-reducing bacteria, Geobacter and Desulfuromonas, can methylate mercury. However, Shewanella strains did not show this mercury methylation ability under tested conditions.
Area of Science:
- Environmental microbiology
- Biogeochemical cycles
Background:
- Mercury methylation is a key process in its environmental cycling.
- Dissimilatory iron-reducing bacteria play significant roles in anaerobic environments.
- Understanding microbial mercury methylation is crucial for assessing environmental risks.
Purpose of the Study:
- To investigate the mercury methylating potential of key dissimilatory iron-reducing bacteria.
- To compare the Hg-methylating ability across different genera: Geobacter, Desulfuromonas, and Shewanella.
Main Methods:
- Culturing of bacterial strains from the genera Geobacter, Desulfuromonas, and Shewanella.
- Incubation under conditions facilitating iron(III), nitrate, or fumarate reduction.
- Quantification of methylmercury production compared to abiotic controls.
Main Results:
- All tested Geobacter and Desulfuromonas strains demonstrated mercury methylation.
- Mercury methylation by Geobacter and Desulfuromonas occurred during the reduction of Fe(III), nitrate, or fumarate.
- No significant methylmercury production was observed in Shewanella strains compared to controls.
Conclusions:
- Geobacter and Desulfuromonas are confirmed Hg-methylating bacteria.
- Shewanella strains tested do not appear to methylate mercury under these conditions.
- These findings highlight the taxonomic distribution of mercury methylation within Deltaproteobacteria.
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