炭床メタンの起源と限界に関するメトキシル安定同位体制約
M K Lloyd1,2, E Trembath-Reichert1,3, K S Dawson1,4
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
Science (New York, N.Y.)
|November 11, 2021
まとめ
微生物による炭床メタンの生産は,石炭中の有機化合物の存在によって制限されており,地質的な時間の中で微生物が植物物質を石炭に変換することを示唆しています. この過程は,石炭床メタンのユニークな炭素同位体シグネチャーを説明します.
科学分野:
- 地質生物学
- 有機地化学
- 石炭の地質学
背景:
- 微生物による炭床メタンは 重要な経済的資源であり 強力な温室効果ガスです
- 炭鉱内の微生物によるメタンの形成を制御する正確な制御は,まだ十分に理解されていません.
- これらのコントロールを理解することは 資源管理と気候変動の緩和に不可欠です
研究 の 目的:
- 炭の微生物分解性が微生物によるメタンの生成を制限するかどうかを調査する.
- 炭鉱におけるメタノゲーゼスを供給する重要な反応としてメトキシル群脱甲基化の役割を決定する.
- 石炭床メタンで観察された独特の炭素同位体組成の起源を解明する.
主な方法:
- 熟成度が異なる炭 (木炭からビタミノス炭) の全体的なサンプルセットにおけるメトキシル群脱塩の分析.
- 残留メトキシル基の炭素同位体組成の測定
- 同位体データを熱的および生物学的反応モデルと比較する.
主要な成果:
- メトキシル群の炭素同位体組成は,熱分解と矛盾しており,生物学的に媒介されたプロセスを示しています.
- データは,炭鉱における微生物メタンの産出を制限する要因としてメトキシル濃度が作用することを示唆している.
- 微生物のメチロトロフィーは,従来の炭化水素堆積物と比較して,石炭床メタンの観測された炭素13濃縮を説明する.
結論:
- 地質学的な時間尺度で 植物物質を石炭に変容させるには 生物圏の微生物のコミュニティが 参加した可能性が高い.
- 炭中のメトキシル群の豊富さは,生物学的生産可能なメタン量に直接影響します.
- この研究は,炭床メタンの形成と同位体シグネチャーを制御する生地化学的経路を明確にします.
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