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| Titel |
Aerobic methanotrophy within the pelagic redox-zone of the Gotland Deep (central Baltic Sea) |
| VerfasserIn |
O. Schmale, M. Blumenberg, K. Kießlich, G. Jakobs, C. Berndmeyer, M. Labrenz, V. Thiel, G. Rehder |
| 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 ; 9, no. 12 ; Nr. 9, no. 12 (2012-12-05), S.4969-4977 |
| Datensatznummer |
250007450
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| Publikation (Nr.) |
 copernicus.org/bg-9-4969-2012.pdf |
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| Zusammenfassung |
| Water column samples taken in summer 2008 from the stratified Gotland Deep
(central Baltic Sea) showed a strong gradient in dissolved methane
concentrations from high values in the saline deep water (max. 504 nM) to
low concentrations in the less dense, brackish surface water (about 4 nM).
The steep methane-gradient (between 115 and 135 m water depth) within the
redox-zone, which separates the anoxic deep part from the oxygenated surface
water (oxygen concentration 0–0.8 mL L−1), implies a methane
consumption rate of 0.28 nM d−1. The process of microbial methane
oxidation within this zone was evident by a shift of the stable carbon
isotope ratio of methane between the bottom water (δ13C CH4 = −82.4‰
and the redox-zone (δ13C CH4 = −38.7‰. Water column samples
between 80 and 119 m were studied to identify the microorganisms responsible
for the methane turnover in that depth interval. Notably, methane
monooxygenase gene expression analyses for water depths covering the whole
redox-zone demonstrated that accordant methanotrophic activity was probably
due to only one phylotype of the aerobic type I methanotrophic bacteria. An
imprint of these organisms on the particular organic matter was revealed by
distinctive lipid biomarkers showing bacteriohopanepolyols and lipid fatty
acids characteristic for aerobic type I methanotrophs (e.g.,
35-aminobacteriohopane-30,31,32,33,34-pentol), corroborating their role in
aerobic methane oxidation in the redox-zone of the central Baltic Sea. |
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