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Autotrophic ammonia oxidation by soil thaumarchaea
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| Zeitschriftentitel: | Proceedings of the National Academy of Sciences |
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| Personen und Körperschaften: | , , , , , |
| In: | Proceedings of the National Academy of Sciences, 107, 2010, 40, S. 17240-17245 |
| Format: | E-Article |
| Sprache: | Englisch |
| veröffentlicht: |
Proceedings of the National Academy of Sciences
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| Schlagwörter: |
| Zusammenfassung: | <jats:p> Nitrification plays a central role in the global nitrogen cycle and is responsible for significant losses of nitrogen fertilizer, atmospheric pollution by the greenhouse gas nitrous oxide, and nitrate pollution of groundwaters. Ammonia oxidation, the first step in nitrification, was thought to be performed by autotrophic bacteria until the recent discovery of archaeal ammonia oxidizers. Autotrophic archaeal ammonia oxidizers have been cultivated from marine and thermal spring environments, but the relative importance of bacteria and archaea in soil nitrification is unclear and it is believed that soil archaeal ammonia oxidizers may use organic carbon, rather than growing autotrophically. In this soil microcosm study, stable isotope probing was used to demonstrate incorporation of <jats:sup>13</jats:sup> C-enriched carbon dioxide into the genomes of thaumarchaea possessing two functional genes: <jats:italic>amoA</jats:italic> , encoding a subunit of ammonia monooxygenase that catalyses the first step in ammonia oxidation; and <jats:italic>hcd</jats:italic> , a key gene in the autotrophic 3-hydroxypropionate/4-hydroxybutyrate cycle, which has been found so far only in archaea. Nitrification was accompanied by increases in archaeal <jats:italic>amoA</jats:italic> gene abundance and changes in <jats:italic>amoA</jats:italic> gene diversity, but no change was observed in bacterial <jats:italic>amoA</jats:italic> genes. Archaeal, but not bacterial, <jats:italic>amoA</jats:italic> genes were also detected in <jats:sup>13</jats:sup> C-labeled DNA, demonstrating inorganic CO <jats:sub>2</jats:sub> fixation by archaeal, but not bacterial, ammonia oxidizers. Autotrophic archaeal ammonia oxidation was further supported by coordinate increases in <jats:italic>amoA</jats:italic> and <jats:italic>hcd</jats:italic> gene abundance in <jats:sup>13</jats:sup> C-labeled DNA. The results therefore provide direct evidence for a role for archaea in soil ammonia oxidation and demonstrate autotrophic growth of ammonia oxidizing archaea in soil. </jats:p> |
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| Umfang: | 17240-17245 |
| ISSN: |
0027-8424
1091-6490 |
| DOI: | 10.1073/pnas.1004947107 |