コメント on "の代わりにヒ素を用いて増殖できる細菌"
James B Cotner1, Edward K Hall
1Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN 55108, USA. cotne002@umn.edu
まとめ
研究者らは,細菌株GFAJ-1がリンをヒ素に置き換えることができることを発見しました. これは,バクテリアの生命と成長に不可欠な要素に関する以前の仮定に異議を唱えます.
科学分野:
- 微生物学 微生物学とは
- 天体生物学 アストロバイオロジー
- バイオケミストリー バイオケミストリー
背景:
- すべての生命に不可欠なリン (P) は,生物学の長年の原則です.
- バクテリア株GFAJ-1は,以前,P. arsenic (As) を潜在的に代替する可能性があると報告されていた.
- As-rich,P-limited mediaで育ったGFAJ-1のP含有量は,予想より大幅に低かった.
研究 の 目的:
- バクテリア菌株GFAJ-1がリンの代わりにヒ素を利用する能力を調査する.
- GFAJ-1におけるヒ素-リン置換の生化学的基礎を理解する.
- この発見が生命の定義と地球外生命の検出に及ぼす影響を調査する.
主な方法:
- 細菌株GFAJ-1の培養は,アルゼンが多く,リンが限られている条件下で行われます.
- これらの条件下で栽培されたGFAJ-1バイオマスの元素組成を分析する.
- 同位体ラベリングと質量スペクトロメトリーを使用して,バイオ分子へのヒ素の組み込みを追跡します.
主要な成果:
- GFAJ-1は,高濃度のヒ素を含み,検出可能なリンを含まない環境で成長を示した.
- +As/-P媒介で培育されたGFAJ-1細胞のP含有量は著しく減少したが,完全に欠けることはなかった.
- 証拠によると,ヒ素は重要なバイオ分子に組み込まれ,潜在的にリンを模倣している.
結論:
- この研究は,一部の細菌がヒ素をバイオケミストリーに組み込み,普遍的なの要求事項に異議を唱える可能性があるという証拠を提供します.
- この発見は,生物で可能な元素置換の既知の範囲を拡大する.
- とリンを代用する能力は,多様な化学環境における地球外生命の探求に影響を及ぼします.
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