通过水热喷气孔在92摄氏度固定气的archaeon
Mausmi P Mehta1, John A Baross
1School of Oceanography, University of Washington, Seattle, WA 98195, USA. mausmi@alum.mit.edu
概括
科学家们发现了一种能够在92°C下进行生物固定的超热友性archaeon,在极端环境中扩大了这种重要过程的已知温度极限.
科学领域:
- 微生物学 微生物学
- 生物化学 生物化学
- 极端爱好研究 极端爱好研究
背景情况:
- 生物固化对生命至关重要,它将大气中的 (N2) 转化为氨 (NH3).
- 已知的生物固定的上限温度以前是64°C.
- 深海的热水喷口拥有独特的微生物群落,适应极端的温度和压力.
研究的目的:
- 研究超热友微生物中生物固定的潜力.
- 为了识别和描述来自深海热水喷口的新型固生物.
- 为了确定固的温度上限.
主要方法:
- 从深海热水风口液中分离和培养微生物.
- 16S核糖体RNA基因测序用于遗传学分析.
- 使用同位素标记 ((15) N2) 测量固活性.
- 通过信使RNA检测对酶基因 (nifH) 表达的分析.
主要成果:
- 一种新型的甲原体archaeon,FS406-22,从深海的热水风口液中分离出来.
- 在高达92°C的温度下,FS406-22证明了固化 (将N2减少为NH3).
- 这个温度比生物固定的先前确定的上限高28°C.
- 遗传学分析显示,FS406-22与Methanocaldococcus jannaschii.22密切相关 (99%的16S rRNA相似性).
- 在90°C的最佳生长温度下,FS406-22结合了 (15) N2并表达了 nifH mRNA.
结论:
- 发现FS406-22显著扩大了生物固定的已知温度范围.
- 这一发现表明,在地下生物圈中,生命和循环的潜力更大.
- 这意味着有限的生态系统,即使在极端高温下,也可能支持生物固定.
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