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| Titel |
Constraints on mechanisms and rates of anaerobic oxidation of methane by microbial consortia: process-based modeling of ANME-2 archaea and sulfate reducing bacteria interactions |
| VerfasserIn |
B. Orcutt, C. Meile |
| 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 ; 5, no. 6 ; Nr. 5, no. 6 (2008-11-24), S.1587-1599 |
| Datensatznummer |
250002925
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| Publikation (Nr.) |
 copernicus.org/bg-5-1587-2008.pdf |
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| Zusammenfassung |
| Anaerobic oxidation of methane (AOM) is the main process responsible for the
removal of methane generated in Earth's marine subsurface environments.
However, the biochemical mechanism of AOM remains elusive. By explicitly
resolving the observed spatial arrangement of methanotrophic archaea and
sulfate reducing bacteria found in consortia mediating AOM, potential
intermediates involved in the electron transfer between the methane oxidizing
and sulfate reducing partners were investigated via a consortium-scale
reaction transport model that integrates the effect of diffusional transport
with thermodynamic and kinetic controls on microbial activity. Model
simulations were used to assess the impact of poorly constrained microbial
characteristics such as minimum energy requirements to sustain metabolism and
cell specific rates. The role of environmental conditions such as the
influence of methane levels on the feasibility of H2, formate and acetate
as intermediate species, and the impact of the abundance of intermediate
species on pathway reversal were examined. The results show that higher
production rates of intermediates via AOM lead to increased diffusive fluxes
from the methane oxidizing archaea to sulfate reducing bacteria, but the
build-up of the exchangeable species can cause the energy yield of AOM to
drop below that required for ATP production. Comparison to data from
laboratory experiments shows that under the experimental conditions of
Nauhaus et al. (2007), none of the potential intermediates considered here is
able to support metabolic activity matching the measured rates. |
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