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C. elegans Tracking and Behavioral Measurement
Published on: November 17, 2012
シンビオティックおよびフリーライフのスパイロケータによる窒素固定
T G Lilburn1, K S Kim, N E Ostrom
1Ribosomal Database Project, Center for Microbial Ecology, Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824-1101, USA.
まとめ
Spirochetesは,以前は窒素を固定することが知られていなかったが,窒素酵素活性を持っている. この発見は,それらを termite 栄養とグローバルな窒素循環に巻き込み,未割り当ての窒素酶遺伝子を説明する可能性がある.
科学分野:
- 微生物学 微生物学とは
- バイオケミストリー バイオケミストリー
- 環境科学 環境科学
背景:
- スピロケータは,動物の腸や堆積物を含む様々な環境で一般的に見られる多様な細菌のグループです.
- 窒素の固定,つまり大気中の窒素をアンモニアに変換することは,生命にとって極めて重要なプロセスです.
- 窒素酶遺伝子 (nifH) は,窒素固定能力の重要な指標である.
研究 の 目的:
- スピロケータにおける窒素酶遺伝子ホモログの存在と窒素酶活性を調べる.
- 窒素栄養におけるスパイロケータの役割,特に白における役割を決定する.
- 世界的な窒素循環におけるスパイロケート窒素固定の影響を調査する.
主な方法:
- ニフH遺伝子のホモログの為に,セロミトのや淡水の沈殿物からスピロケータゲノムをスクリーニングする.
- 選定されたスピロケータ単離体における窒素酵素活性測定,甲虫腸トレポネマZAS-9およびスピロケータ・オーランティアを含む.
- 口腔および反性のトレポネームにおけるnifH同類体の存在を分析する.
主要な成果:
- 甲虫の腸や堆積物からのスパイロケータは,nifH遺伝子のホモログを持つことが判明しました.
- これらのスパイロケータで窒素酵素の活性が実証され,この属の新発見である.
- ヒトの口腔および牛の歯類のトレポネームで nifH ホモログを特定した.
- トレポネマZAS-9とスピロケータ・オーランティアに15-ジノトゲン固定が確認された.
結論:
- スピロケータは窒素を固定する代謝能力を持っています.
- スピロケータは, termiesの窒素栄養とグローバルな窒素サイクルに寄与する可能性があります.
- Spirochetesは,環境サンプルで以前に割り当てられていない nifH 遺伝子の源を代表する可能性があります.
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