ベンティック・フォーアミニフェアで完全な脱窒化が証明されている

Nils Risgaard-Petersen¹, Alexandra M Langezaal, Signe Ingvardsen

¹Department of Marine Ecology, National Environmental Research Institute, Vejlsøvej 25, DK-8600 Silkeborg, Denmark. nri@dmu.dk

Nature

|September 8, 2006

まとめ

ベンシック・フォラミニフェラは細胞内窒素を貯蔵し,吸い込み,無毒海洋環境での生存を可能にします. この発見は,窒素循環にとって極めて重要な,これまで説明されていない無酸素代謝を明らかにしています.

科学分野:

マリン・バイオロジーマリン・バイオロジー
地質化学地質化学
微生物学微生物学とは

背景:

ベンシック・フォラミニフェラは,海洋堆積物の中で豊富に存在する単細胞性ユーカリ生物です.
多くの種は無酸素環境に住んでいますが,持続可能な無酸素代謝は十分に理解されていません.

研究の目的:

ベンシックフォラミニフェラの無酸素代謝を調査する.
フォラミニフェラが酸素のない生息地での呼吸のために貯蔵された窒素を活用できるかどうかを判断する.

主な方法:

フォラミニフェラにおける細胞内窒素貯蔵量の定量化.
窒素の利用を確認するための呼吸実験.
スウェーデンのフィヨルドとチリ大陸棚の堆積物におけるフィールドサンプリング.

主要な成果:

Globobulimina pseudospinescensが細胞内窒素を二酸化窒素ガスに蓄積し,呼吸することを実証した.
推定ニートレートの貯蔵量は1ヶ月以上の呼吸に十分である.
複数の支配的なベンティック型フォラミニフェラ種で高細胞内窒素濃度が検出されました.

結論:

フォラミニフェラは,細胞内窒素を用いた持続的な無酸素代謝経路を持っています.
フォラミニフェラは,海洋の窒素循環において重要な役割を果たしている可能性が高い.
海洋窒素循環に関する現在の理解は,フォアミニフェラル貢献を含めるため,さらなる精細化が必要である.

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