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Medium Preparation for the Cultivation of Microorganisms under Strictly Anaerobic/Anoxic Conditions
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A microbial consortium couples anaerobic methane oxidation to denitrification
Ashna A Raghoebarsing1, Arjan Pol, Katinka T van de Pas-Schoonen
1Department of Microbiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
Nature
|April 14, 2006
Summary
Scientists discovered a new microbial process where methane is converted to carbon dioxide using nitrate in the absence of oxygen. This finding challenges previous beliefs about methane oxidation and impacts global methane and nitrogen cycles.
Area of Science:
- Environmental microbiology
- Biogeochemical cycles
Background:
- Modern agriculture intensifies global methane and nitrogen cycles.
- Freshwater sediments receive increased nitrate and methane fluxes.
- Anaerobic methane oxidation was previously thought to require oxygen or sulfate.
Purpose of the Study:
- To investigate the possibility of anaerobic methane oxidation coupled to denitrification.
- To identify microorganisms capable of this process.
Main Methods:
- Enrichment of a microbial consortium from anoxic freshwater sediments.
- Incubation of the consortium under anaerobic conditions with methane and nitrate.
- Analysis of methane oxidation and denitrification products.
Main Results:
- A microbial consortium directly oxidized methane to carbon dioxide coupled to denitrification anaerobically.
- The consortium comprised a novel bacterium and an archaeon.
- Relatives of these microorganisms are widespread in freshwater ecosystems.
Conclusions:
- Direct anaerobic oxidation of methane coupled to denitrification is a viable microbial process.
- This newly identified pathway may significantly contribute to global methane and nitrogen cycling.
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