バクテリアの鉄還元過程における硫黄媒介電子シャトルング
Theodore M Flynn1, Edward J O'Loughlin2, Bhoopesh Mishra3
1Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA. Computation Institute, University of Chicago, Chicago, IL 60637, USA.
まとめ
塩基条件下では,微生物が元素硫黄 (S(0) を使用して,水層内の鉄 (Fe(III)) を間接的に減少させます. このS(0) 媒介経路は,直接的な微生物によるFe(III) 還元が阻害される鉄循環において極めて重要です.
科学分野:
- バイオジオケミストリー バイオジオケミストリー
- 微生物生態学 微生物生態学とは
- 環境科学 環境科学
背景:
- 微生物による鉄酸鉄 [Fe (III) ]の還元は,無毒水層における重要なプロセスである.
- 分離型金属還元細菌は,異なる地下水のpH下では,元素硫黄 (S(0) のような代替電子受容体を利用することができる.
- アルカリの条件は,多くの水層システムで一般的であり,微生物の呼吸に影響を与えます.
研究 の 目的:
- 塩基条件下での鉄と硫黄の循環の相互作用を調査する.
- 直接的な微生物呼吸が制限されたときにFe (III) の減少のメカニズムを理解する.
主な方法:
- 熱力学地化学モデリング. 熱力学地化学モデリング.
- 細菌Shewanella oneidensis MR-1を使用したバイオリアクターの実験.
- 制御されたアルカリ条件下で微生物と地化学相互作用の分析.
主要な成果:
- Shewanella oneidensis MR-1は,アルカリ条件下では,S(0) を酵素的に減少させるが,ゴエチット (α-FeOOH) は発生しない.
- 硫化物 (HS(-)) は,S(0) の還元から生成されるアビオティックに還元されたゴエチートである.
- これは,S(0) によって媒介される間接的なFe(III) 還元経路を示しています.
結論:
- 元素硫黄 (S(0) は,アルカリ水層におけるFe(III) の減少のために電子シャトルとして作用することができます.
- S(0) 媒介の経路は,直接的な微生物のFe(III) 還元が阻害される鉄の生地化学サイクルにとって重要である.
- この発見は,様々な水層環境における生地化学的プロセスを理解するための意味を持つ.
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