Endolithic microbial diversity in sandstone and granite from the McMurdo Dry Valleys, Antarctica
Endolithic microbial diversity in sandstone and granite from the McMurdo Dry Valleys, Antarctica
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DOI：
10.1007/s00300-016-2024-9
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发表时间：
2017-05-01
期刊：
影响因子：
1.7
通讯作者：
Pointing, Stephen B.
中科院分区：
文献类型：
--
作者：
Archer, Stephen D. J.;de los Rios, Asuncion;Pointing, Stephen B.
作为一种避免压力的策略，在南极洲麦克默多干燥山谷的岩石基质中发展出神秘的微生物群落。它们可能是在风化岩石的孔隙空间内的隐形内石器，或者作为碎屑内石器群落在裂缝和裂隙中发育，并以彩色殖民带为特征。在这里，我们使用了一种精密钻头，从殖民花岗岩和砂岩中的黑色、白色、绿色和红色地层中提取分数。我们结合背散射扫描电子显微镜和高通量测序来识别每个区带中的主要分类群。我们确认了藻类和真菌地衣共生体、蓝藻和自由生活的藻类的存在，以及各种异养细菌和古生菌的成分。观察到在社区一级有明确的划分。相对生物多样性和异质性的地衣群落出现在风化砂岩悬崖中，而在花岗岩和砂岩巨石中，蓝藻群落占主导地位。每个群落内殖民的有色人种之间的差异不太明显。这项研究表明，使用类似于在火星上寻找石器时代生物特征的计划的钻探技术，可以恢复石器时代的微生物群落。
Cryptic microbial communities develop within rocky substrates in Antarctica's McMurdo Dry Valleys as a stress avoidance strategy. They may be cryptoendolithic within pore spaces of weathered rocks, or develop in cracks and fissures as chasmoendolithic communities and are characterised by coloured bands of colonisation. Here we used a precision drill to recover fractions from black, white, green and red layers within colonised granite and sandstone. We combined backscattered scanning electron microscopy and high-throughput sequencing to identify major taxa in each band. We confirmed the presence of algal and fungal lichen symbionts, cyanobacteria and free-living algae, plus a diverse heterotrophic bacterial and archaeal component. A clear delineation at the community level was observed. The relatively biodiverse and heterogenous lichen communities occurred in weathered sandstone cliffs, whilst in granite and sandstone boulders, cyanobacterial communities were dominant. Differences between coloured bands of colonisation within each community were less clear. The study demonstrates that endolithic microbial communities can be recovered using a drill technology similar to that planned for the search for endolithic biosignatures on Mars.