在8600万年前的深海红色粘土中,有氧微生物呼吸
Hans Røy1, Jens Kallmeyer, Rishi Ram Adhikari
1Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark. hans.roy@biology.au.dk
Science (New York, N.Y.)
|May 19, 2012
概括
深海微生物群落通过大幅降低呼吸速率而生存数百万年. 这种新陈代谢适应使沉积物保持氧化,支持极端环境中的生命.
科学领域:
- 海洋微生物学 海洋微生物学
- 地质化学 地质化学
- 深层生物圈研究研究 深层生物圈研究
背景情况:
- 微生物生活在深海沉积物中持续存在,在没有新鲜有机物质的情况下生存了数百万年.
- 沉积率会影响地下环境中的氧气透和微生物活动.
- 北太平洋旋转提供了一个独特的环境来研究长期微生物生存.
研究的目的:
- 在深度海洋沉积物中研究微生物呼吸速率.
- 了解能量流和微生物群体大小之间的关系.
- 确定微生物代谢如何维持古代沉积物中氧化的条件.
主要方法:
- 在海洋沉积物中的不同深度测量氧气呼吸速率.
- 微生物细胞特异性呼吸的分析.
- 用放射测年法测年沉积层,以确定其年龄.
主要成果:
- 氧气呼吸率随着沉积物深度显著下降,从界面上的10μmol O(2) L−1 yr−1降至30米处的0.001μmol O(2) L−1 yr−1.
- 细胞特异性呼吸率随着深度的增加而下降,稳定在10−3 fmol O(2) 细胞-1天-1.1周左右.
- 发现微生物群落的大小受碳氧化率和能量可用性调节.
结论:
- 深海微生物群落表现出极低的代谢率,使得它们能够长期生存.
- 能量流是控制微生物群落大小和深沉积物中的活动的关键限制因素.
- 古代海洋沉积物的持续氧化是由这些高效,低能量的新陈代谢促进的.
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