深海のアーケアは,メタンを消費する微生物のコンソーシアムで窒素を固定し,共有します
Anne E Dekas1, Rachel S Poretsky, Victoria J Orphan
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. dekas@gps.caltech.edu
Science (New York, N.Y.)
|October 17, 2009
まとめ
深海のアーケアは窒素 (N2) を固定し,それを細菌の共生体と共有する. この発見により,これらの微生物は,海洋の炭素,窒素,硫黄の循環において重要な役割を果たしていることが明らかになった.
科学分野:
- マリン・マイクロバイオロジー
- バイオジオケミストリー バイオジオケミストリー
- 微生物生態学とは
背景:
- ダイアゾトロフィック微生物は,生態系の生産性にとって極めて重要です.
- 多くの海洋環境におけるダイアゾトロフのアイデンティティは,ほとんど不明のままである.
- アナエロビックメタン酸化アーカイアとその細菌共生体は,深海の生態系における重要なメタン吸収源である.
研究 の 目的:
- 深海の環境でダイアゾトロフを特定するために.
- 窒素固定における無酸素メタン酸化アーキアの役割を調査する.
- 栄養循環におけるアーカイアとバクテリアの共生関係を理解する.
主な方法:
- シングルセル解像度ナノメートル二次イオン質量スペクトロメトリ (NanoSIMS) 画像撮影.
- 窒素固定を追跡するための15N組み込み分析.
- 代謝経路を明らかにするために安定同位体探査.
主要な成果:
- 深海の無酸素メタン酸化アーケアは,窒素固定生物として特定されました.
- これらの古生物は,N2と構造的に類似した化合物,例えばCN-を固定します.
- 窒素固定製品は,硫酸塩を減少させる細菌共生体と共有されます.
- 古代メタンの酸化率は窒素固定の間維持されたが,成長率は減少した.
- これらの考古学/細菌コンソーシアムは,生物利用可能な窒素の新たに特定された源である.
結論:
- 深海のアーキアは,海洋の窒素循環に大きく貢献しています.
- 特定された考古学/細菌のコンソーシアムは,世界の炭素,窒素,硫黄のサイクルを結びつけています.
- この研究は,微生物のコミュニティにおける窒素固定のエネルギー限界についての理解を広げています.
- この発見は,生地化学的プロセスにおける共生関係が果たす重要な役割を強調しています.
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