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| Titel |
An experimental study on short-term changes in the anaerobic oxidation of methane in response to varying methane and sulfate fluxes |
| VerfasserIn |
G. Wegener, A. Boetius  |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 6, no. 5 ; Nr. 6, no. 5 (2009-05-18), S.867-876 |
| Datensatznummer |
250003748
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| Publikation (Nr.) |
 copernicus.org/bg-6-867-2009.pdf |
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| Zusammenfassung |
| A major role in regulation of global methane fluxes has
been attributed to the process of anaerobic oxidation of methane (AOM),
which is performed by consortia of methanotrophic archaea and sulfate
reducing bacteria. An important question remains how these energy limited,
slow growing microorganisms with generation times of 3–7 months respond to
rapid natural variations in methane fluxes at cold seeps. We used an
experimental flow-through column system filled with cold seep sediments
naturally enriched in methanotrophic communities, to test their responses to
short-term variations in methane and sulfate fluxes. At stable methane and
sulfate concentrations of ~2 mM and 28 mM, respectively, we measured
constant rates of AOM and sulfate reduction (SR) for up to 160 days of
incubation. When percolated with methane-free medium, the anaerobic
methanotrophs ceased to produce sulfide. After a starvation phase of 40
days, the addition of methane restored former AOM and SR rates immediately.
At methane concentrations between 0–2.3 mM we measured a linear correlation
between methane availability, AOM and SR. At constant fluid flow velocities
of 30 m yr−1, ca. 50% of the methane was consumed by the
anaerobic methanotrophic (ANME) population at all concentrations tested.
Reducing the sulfate concentration from 28 to 1 mM, a decrease in AOM and SR
by 50% was observed, and 45% of the methane was consumed. Hence, the
marine anaerobic methanotrophs (ANME) are capable of oxidizing substantial
amounts of methane over a wide and variable range of fluxes of the reaction
educts. |
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