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Laboratory Simulation of an Iron(II)-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria
Published on: July 24, 2016
Manganese- and iron-dependent marine methane oxidation
Emily J Beal1, Christopher H House, Victoria J Orphan
1Department of Geosciences and Penn State Astrobiology Research Center, Pennsylvania State University, University Park, PA 16802, USA. ejbeal@gmail.com
Science (New York, N.Y.)
|July 11, 2009
Summary
Anaerobic methane oxidation (AOM) can use iron and manganese, not just sulfate. This finding expands our understanding of methane cycling and its role in Earth's climate regulation.
Area of Science:
- Environmental microbiology
- Biogeochemical cycles
- Climate science
Background:
- Anaerobic methanotrophs are crucial for regulating Earth's climate.
- Anaerobic oxidation of methane (AOM) is typically considered sulfate-dependent.
- Other electron acceptors are more energetically favorable for AOM than sulfate.
Purpose of the Study:
- To investigate alternative electron acceptors for anaerobic methane oxidation in marine environments.
- To determine if manganese and iron can support AOM in marine sediment.
Main Methods:
- Collected marine methane-seep sediment from the Eel River Basin, California.
- Enriched microbial communities capable of anaerobic methane oxidation.
- Assessed the utilization of manganese (birnessite) and iron (ferrihydrite) as electron acceptors for methane oxidation.
Main Results:
- Microorganisms from marine methane-seep sediment can oxidize methane using manganese and iron.
- This demonstrates that marine AOM is coupled to a wider range of oxidants than previously recognized.
- Manganese and iron are supplied to oceans by rivers, suggesting potential global significance.
Conclusions:
- Marine anaerobic oxidation of methane is not limited to sulfate as an electron acceptor.
- Manganese- and iron-dependent AOM have the potential to be globally important processes.
- This expands the known microbial pathways influencing methane cycling and climate regulation.
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