Biotic and abiotic mercury methylation and demethylation in sediments
- Universite du Quebec, Montreal (Canada)
Inorganic mercury (Hg(II)) methylation and methylmercury (MeHg) demethylation may occur in the water column, sediment-water interface and subsurficial sediment of aquatic ecosystems. These transformations involve mainly microbial mechanisms, although abiotic methylation may play a more important role in the water compartment. The relative importance of biotic versus abiotic mechanisms of methylation has not been determined however, and abiotic demethylation remains unknown. Little quantitative information is available on the role of bacterial activity in mercury transformations. It has been reported that at least 16 genera of aerobic and anaerobic microorganisms are able to methylate HG(II), and that a greater number are able to demethylate MeHg. Nevertheless, not all populations of these species are capable of methyl- and demethyl-transformations. The actual concentration of MeHg in the aquatic environment is regulated by the relative production and decomposition rates. This, in turn, depends on the availability of Hg(II), MeHg, and bacteria as well as on the physico-chemical properties of the sample. The objective of this study was to compare mercury methylation and demethylation rates in sediment samples with and without active bacterial populations. We therefore performed experiments to follow bacterial evolution during the course of Hg(II) methylation and MeHg demethylation in sediment slurries containing both sterile and non-sterile sediments.
- OSTI ID:
- 6759671
- Journal Information:
- Bulletin of Environmental Contamination and Toxicology; (United States), Journal Name: Bulletin of Environmental Contamination and Toxicology; (United States) Vol. 52:5; ISSN 0007-4861; ISSN BECTA6
- Country of Publication:
- United States
- Language:
- English
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540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
AQUATIC ECOSYSTEMS
BACTERIA
BIODEGRADATION
CHEMICAL REACTIONS
CONTAMINATION
DECOMPOSITION
ECOSYSTEMS
ELEMENTS
MERCURY
METALS
METHYLATION
METHYLMERCURY
MICROORGANISMS
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
SEDIMENTS