氨氧化动力学决定了化古生物学和细菌的利基区分
Willm Martens-Habbena1, Paul M Berube, Hidetoshi Urakawa
1Department of Civil & Environmental Engineering, University of Washington, Seattle, Washington 98105, USA. willmmh@u.washington.edu
Nature
|October 2, 2009
概括
氧化氨的古生物,如Candidatus Nitrosopumilus maritimus,在海洋循环中发挥着关键作用. 它们独特的生理学允许高效的化,即使在营养有限的海洋水中.
科学领域:
- 微生物学 微生物学
- 环境科学 环境科学
- 生物地质化学生物地质化学
背景情况:
- 氨氧化对于全球循环至关重要.
- 考古物,特别是Crenarchaeota,越来越多地被认为是它们在化中的作用.
- 关于氨氧化古生物学对海洋化作用的生理学和贡献的知识有限.
研究的目的:
- 为了研究氧化动力学和细胞特征的中性crenarchaeon"候选人Nitrosopumilus海洋"菌株SCM1.1.
- 为了了解这种archaeon适应于寡质环境的适应.
- 为了确定氨氧化阿基亚对海洋化的贡献.
主要方法:
- 在寡性条件下种植"Candidatus Nitrosopumilus maritimus"SCM1菌株.
- 在不同度下测量氨氧化速率.
- 确定动力参数,包括半和常数 (K(m)) 和基质值.
- 对细胞特征的分析,这些特征与营养有限的生长有关.
主要成果:
- 在开放海洋的低度下,SCM1表现出高的氨氧化率.
- 生物体的半和常数 (K(m) = 133 nM总) 和基质值 (<或=10 nM) 与现场海洋化速率一致.
- SCM1对减少具有很高的特定亲和力 (每小时每克细胞68700升).
- 这些特征表明适应极端的营养限制.
结论:
- 氧化氨的古生物是对化在寡质海洋环境中的重要贡献者.
- SCM1的高基质亲和力表明它对其他海洋微生物有竞争能力.
- 化在海洋循环中可能比目前建模的更为普遍.
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