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Updated: Jul 12, 2026
09:33
An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
Methylmercury: bacterial degradation in lake sediments
Science (New York, N.Y.)
|April 13, 1973
Summary
Lake sediment microbes initially produced methylmercury from inorganic mercury. Further incubation led to methylmercury breakdown and volatile mercury release, with pure cultures degrading methylmercury to methane and mercury (Hg(0)).
Area of Science:
- Environmental Microbiology
- Biogeochemistry
- Mercury Contamination
Background:
- Mercury (Hg) is a toxic heavy metal with complex environmental cycling.
- Methylmercury is a highly toxic organic form of mercury.
- Lake sediments are a key environment for mercury methylation and demethylation processes.
Purpose of the Study:
- To investigate the microbial transformation of inorganic mercury in lake sediments.
- To identify microorganisms capable of methylmercury degradation.
- To characterize the end products of methylmercury breakdown.
Main Methods:
- Incubation of lake sediments with inorganic mercury (Hg(2+)).
- Culturing of microbial consortia and isolation of pure bacterial strains.
- Analysis of headspace gases using flame ionization gas chromatography (methane) and mass spectrometry (Hg(0)).
Main Results:
- Initial accumulation of methylmercury followed by its rapid decrease and volatilization of inorganic mercury (Hg(0)).
- Demonstration of methylmercury degradation by a mixed microbial culture.
- Isolation of four bacterial strains that degrade methylmercury to methane and Hg(0) in pure culture.
Conclusions:
- Lake sediment microbial communities can transform inorganic mercury to methylmercury and subsequently degrade methylmercury.
- Specific bacterial isolates are responsible for the demethylation and volatilization of mercury.
- This microbial process plays a crucial role in the environmental fate of mercury.
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