土壌におけるキラル汚染物質の分解に対する環境変化の影響
D L Lewis1, A W Garrison, K E Wommack
1US Environmental Protection Agency, Ecosystems Research Division, National Exposure Research Laboratory, Athens, Georgia 30605, USA. LewisDaveL@aol.com
Nature
|November 30, 1999
まとめ
土壌における環境の変化は,化学エナティオメアの変換のための微生物の好みを変化させることができます. これは,農薬のようなキラル汚染物質の環境的運命と潜在的な毒性に影響を与えます.
科学分野:
- 環境化学 環境化学
- 微生物生態学とは
- 環境毒性学 環境毒性学
背景:
- 農薬を含む多くの環境化学物質はキラルであり,エナンティオマーとして存在します.
- エナントオメアは,異なる生物学的効果と分解速度を示すことができます.
- 微生物の変換プロセスはしばしばエナチオセレクティブである.
研究 の 目的:
- 環境の変化が化学分解における微生物のエナンチオセレクティビティにどのように影響するかを調査する.
- 変化したエンアンチオセレクティビティが,キラル汚染物質の環境リスクに影響するかどうかを判断する.
主な方法:
- フィールドと実験室での実験は,ブラジルと北米の土壌で行われました.
- ディクロロプロップとメチルディクロロプロップのエナンチオメアのエナンチオセクティブ変換を測定した.
- 土地利用 (牧草 vs 森林) と栄養濃縮などの環境要因の影響が評価されました.
主要な成果:
- ブラジルの牧草地の土壌は,二塩ロプロプの非除草剤エナンチオメールを好ましく分解した.
- 森林の土壌は異なるエナチオセレクティブ性を示し,除草剤のエナチオメールをより容易にまたは等しく分解しました.
- 有機栄養素の濃縮により,エナチオセレクティビティは,非除草剤であるメチルジクロプロップのエナチオメアを分解する方向にシフトし,残留の植物毒性を潜在的に増加させました.
結論:
- 土地利用や栄養素の利用可能性などの環境の変化は,キラル汚染物質の微生物のエナチオセレクティブ変換を大幅に変化させます.
- これらのシフトは,化学物質の環境運命を変化させ,化学物質の潜在的毒性を変化させることができます.
- キラル化学汚染物質のリスク評価は,微生物のエナチオ選択性とその環境調節を考慮する必要があります.
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