植物ペクチンによる塩化物のメチル化:効率的で環境的に重要なプロセス
John T G Hamilton1, W Colin McRoberts, Frank Keppler
1Department of Agriculture and Rural Development for Northern Ireland, Newforge Lane, Belfast BT9 5PX, UK. jack.hamilton@dardni.gov.uk
Science (New York, N.Y.)
|July 12, 2003
まとめ
植物物質,特にペクチンの塩化物を塩化メタン (CH3Cl) に容易に変換する一般的な非生物学的メカニズムがあります. この過程は,陸上の生態系とバイオマス燃焼において重要なものであり,大気中のCH3Cl.のほとんどを占める可能性が高い.
科学分野:
- 環境化学 環境化学
- バイオジオケミストリー バイオジオケミストリー
- 大気科学 大気科学
背景:
- 大気中のクロロメタン (CH3Cl) は,平流層のオゾン層の減少に重要な役割を果たしています.
- CH3Cl.の発生源,沈殿地,形成過程については,依然として重大な不確実性が残っています.
- 自然なCH3Cl生成を理解することは,大気モデリングに不可欠です.
研究 の 目的:
- 陸上の環境におけるCH3Cl生成のための共通のメカニズムを特定し,特徴づけること.
- CH3Cl合成における植物物質とペクチンの役割を調査する.
- 異なる温度下での植物物質からのCH3Cl排出量を定量化するために.
主な方法:
- 植物材料における塩化物のCH3Clへのアビオティック変換の実験調査.
- この反応でメチルドナーとしてペクチンを利用する.
- 環境および高温で老朽化した葉や枯れた葉から発生するCH3Cl排出量を測定する.
主要な成果:
- クロリドのCH3Clへのアビオティック変換は,植物材料で容易に発生することが観察されました.
- ペクチンはメチルドナーとして作用する重要な成分として特定されました.
- 大量のCH3Cl排出量が,温度とともに増加する老朽化した葉や枯れた葉から検出されました.
結論:
- 陸上の生態系に至る所に存在するアビオティックなプロセスがCH3Cl.Clを生成する.
- 植物物質とバイオマスの燃焼時に活発なこのペクチン媒介メカニズムは,大気中のCH3Cl.の大部分に貢献している可能性が高い.
- この経路に関するさらなる研究は,正確な大気化学とオゾン層の評価のために不可欠です.
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