深海の堆積物における地下生物の代謝活動
Steven D'Hondt1, Scott Rutherford, Arthur J Spivack
1Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA. dhondt@gso.uri.edu
まとめ
海洋沈殿物の地図は,微生物の生命の独特なゾーンを明らかにしています. メタンは硫酸塩が乏しい地域で豊富に存在し,硫酸塩を減少させるメタンの酸化ゾーンで最も高い活性が見られる.
科学分野:
- 地質化学 地質化学
- 微生物学 微生物学とは
- 海洋学 海洋学 海洋学
背景:
- 海の堆積物には,多様な微生物のコミュニティが宿っている.
- 地表下の代謝活動は,生地化学的サイクルにとって極めて重要です.
- 海洋堆積物における微生物の生命を理解することは,地球の深層生物圏を理解するための鍵です.
研究 の 目的:
- 海洋堆積物における硫酸塩とメタンの世界的な分布をマッピングする.
- 地下代謝活動の領域を特定する.
- 海洋環境における微生物の代謝を制御する要因を調査する.
主な方法:
- 全世界の海洋沈殿物のデータの分析.
- 硫酸塩とメタンの濃度のマッピング.
- メタボリックアクティビティゾーンの特定.
主要な成果:
- 地下代謝活動の2つの主要な領域が特定されました:オープンオーシャン (硫酸塩が豊富) と海洋縁 (硫酸塩が限られている).
- メタンは両省で生産されているが,硫酸塩が乏しい堆積物のみに豊富に存在する.
- 最も高い代謝活動は,海辺に沿った硫酸塩還元メタンの酸化の狭いゾーンで起こります.
結論:
- 海洋沈殿物の地表微生物の代謝は空間的に構造化されています.
- 硫酸塩の利用可能性とメタンの濃度は,微生物の活動を制御する重要な要因です.
- 地下部の堆積物中の微生物生物は,地表生物と比較して,非常に低い代謝率を示しています.
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