マンガンと鉄に依存する海洋メタンの酸化
Emily J Beal1, Christopher H House, Victoria J Orphan
1Department of Geosciences and Penn State Astrobiology Research Center, Pennsylvania State University, University Park, PA 16802, USA. ejbeal@gmail.com
まとめ
アナエロビックメタン酸化 (AOM) は,硫酸塩だけでなく,鉄とマンガンを使用することができます. この発見は,メタンの循環と地球の気候調節におけるメタンの役割に関する私たちの理解を広げています.
科学分野:
- 環境微生物学 環境微生物学
- バイオジオケミカルサイクルとは
- 気候科学 気候科学
背景:
- アナエロビックメタノトロフは,地球の気候の調節に不可欠です.
- メタンの無酸素酸化 (AOM) は通常,硫酸塩依存性と考えられています.
- 他の電子受容体は,硫酸塩よりもエネルギー的にAOMに有利である.
研究 の 目的:
- 海洋環境における無酸素メタンの酸化のための代替電子受容体を調査する.
- マンガンと鉄が海洋堆積物中のAOMをサポートできるかどうかを判断する.
主な方法:
- カリフォルニア州イール川流域の海洋メタン浸透堆積物を集めた.
- アナーロビックメタンの酸化を行うことができる微生物のコミュニティを豊かにした.
- メタンの酸化のための電子受容体としてマンガン (ビルネサイト) と鉄 (フェリヒドライト) の利用を評価した.
主要な成果:
- 海洋のメタン浸透堆積物からの微生物は,マンガンと鉄を使用してメタンを酸化することができます.
- これは,海洋AOMが,これまで認識されていたよりも広い範囲の酸化物質と結合していることを示しています.
- マンガネスと鉄は河川によって海に供給され,潜在的に地球規模の重要性を示唆しています.
結論:
- メタンの海洋無酸素酸化は,電子受容体としての硫酸塩に限定されていません.
- マンガンと鉄に依存するAOMは,世界的に重要なプロセスになる可能性があります.
- これにより,メタンの循環と気候の調節に影響を与える既知の微生物の経路が拡張されます.
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