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| Titel |
Effect of CO2 enrichment on bacterial metabolism in an Arctic fjord |
| VerfasserIn |
C. Motegi, T. Tanaka, J. Piontek, C. P. D. Brussaard, J.-P. Gattuso, M. G. Weinbauer |
| 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 ; 10, no. 5 ; Nr. 10, no. 5 (2013-05-15), S.3285-3296 |
| Datensatznummer |
250018251
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| Publikation (Nr.) |
 copernicus.org/bg-10-3285-2013.pdf |
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| Zusammenfassung |
| The anthropogenic increase of carbon dioxide (CO2) alters the seawater
carbonate chemistry, with a decline of pH and an increase in the partial
pressure of CO2 (pCO2). Although bacteria play a major role in
carbon cycling, little is known about the impact of rising pCO2 on
bacterial carbon metabolism, especially for natural bacterial communities. In
this study, we investigated the effect of rising pCO2 on bacterial
production (BP), bacterial respiration (BR) and bacterial carbon metabolism
during a mesocosm experiment performed in Kongsfjorden (Svalbard) in 2010.
Nine mesocosms with pCO2 levels ranging from ca. 180 to
1400 μatm were deployed in the fjord and monitored for 30 days.
Generally BP gradually decreased in all mesocosms in an initial phase,
showed a large (3.6-fold average) but temporary increase on day 10, and
increased slightly after inorganic nutrient addition. Over the wide range of
pCO2 investigated, the patterns in BP and growth rate of bulk and
free-living communities were generally similar over time. However, BP of the
bulk community significantly decreased with increasing pCO2 after
nutrient addition (day 14). In addition, increasing pCO2 enhanced the
leucine to thymidine (Leu : TdR) ratio at the end of experiment, suggesting
that pCO2 may alter the growth balance of bacteria. Stepwise multiple
regression analysis suggests that multiple factors, including pCO2,
explained the changes of BP, growth rate and Leu : TdR ratio at the end of
the experiment. In contrast to BP, no clear trend and effect of changes of
pCO2 was observed for BR, bacterial carbon demand and bacterial growth
efficiency. Overall, the results suggest that changes in pCO2
potentially influence bacterial production, growth rate and growth balance
rather than the conversion of dissolved organic matter into CO2. |
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