適度な加熱により,780万年前の堆積物有機物質が生物利用可能になる
Shuchai Gan1,2,3, Verena B Heuer1, Frauke Schmidt1
1MARUM - Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen. Leobener Straße 8, D-28359 Bremen, Germany.
Science advances
|August 20, 2025
まとめ
海洋堆積物の有機物質の分解は 微生物によってではなく 熱によって引き起こされます アビオティックな熱処理により,生物利用可能な化合物が放出され,長期にわたる炭素吸収と地球的な炭素循環に影響を与えます.
科学分野:
- 地化学
- 微生物学
- 有機地化学
背景:
- 海の堆積物には大量の 頑固な有機物質が蓄えられています
- 地下微生物は 極端な深さや温度にも存在します
- これらの環境で生体利用可能な基質を供給するメカニズムは十分に理解されていません.
研究 の 目的:
- 海洋沈殿物の溶けた有機物質 (DOM) の変換における温度の影響を調査する.
- シミュレートされた埋葬条件下で生体利用可能な基板生成の経路を解明する.
主な方法:
- 20°Cから85°Cの温度で7800万年前の海洋沈殿物の化
- 3D光スペクトロスコーピーと超高解像度質量スペクトロメトリを用いた溶けた有機物の分析.
- 金属イオン放出とDOMの生物学的利用可能性のモニタリング
主要な成果:
- 35°Cでは,低生物可用性を持つヒュミックのようなDOMが放出されました.
- 55°Cでは,無生物分解により,より小さく,より生物利用可能なDOMが得られ,発酵が促進されます.
- 85°Cでは,無生物的なプロセスにより,を含有するヒュミック化合物から不活性なH2とアセテートが生成され,発酵を回避した.
結論:
- アビオティックな熱プロセスは,海洋沈殿物の耐火性の有機物質を活性化するために不可欠です.
- 温度によるDOM変換は,微生物の活動と基質の利用可能性に影響します.
- この発見は 炭素の長期貯蔵と 炭素循環の理解を深めるものです
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