Microbial Populations of Stony Meteorites: Substrate Controls on First Colonizers
Microbial Populations of Stony Meteorites: Substrate Controls on First Colonizers
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石陨石的微生物种群：对第一批殖民者的底物控制
DOI：
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发表时间：
2017
影响因子：
5.2
通讯作者：
G. Southam
中科院分区：
文献类型：
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作者：
A. Tait;E. Gagen;Sasha Wilson;A. Tomkins;G. Southam
寻找新鲜的、经过消毒的岩石为生态学家提供了一个干净的石板来测试关于首次殖民和土壤从头进化的想法。由于熔岩的形成需要高温灭菌，因此熔岩之前已被用于首次殖民者研究。然而，新鲜的熔岩通常落在具有相似化学成分和形态矿物丰度的较古老的火山序列上。如果有足够的时间，由于新旧基质之间缺乏对比，这会导致新喷发的熔岩中出现类似的微生物群落。陨石在坠落到地球时是无菌的，它们提供了这样的对比，因为它们的还原化学和镁铁质化学通常与它们着陆的表面不同。从而可以研究社区成员和结构如何随着时间的推移对这种新基质做出反应。我们对澳大利亚纳拉伯平原的陨石和土壤进行了 16S rRNA 基因分析。我们发现，与从每个陨石正下方采样的土壤相比，这些陨石的物种丰富度和均匀度较低。尽管发现的陨石相距数公里，但每颗陨石的群落结构与其他陨石（成分相似）的相似性比其所在土壤的群落结构更相似。陨石以属于放线菌的序列为主，其主要操作分类单位（OTU）被归类为耐辐射红杆菌。变形菌门和拟杆菌门是第二丰富的门。土壤中也以放线菌为主，但程度低于陨石。我们还发现了与铁/硫循环生物地杆菌属相关的 OTU。和脱硫弧菌属。这是一个重要的发现，因为陨石含有丰富的金属和硫，可用作能源。这些生态学发现表明，这些陨石中微生物群落的结构受基质控制，即使在大约 10 年后也不会与纳拉伯群落达到稳态。 35,000 年。我们的研究结果表明，陨石提供了一种独特的、无菌的基质，可以用来测试与第一批殖民者有关的想法。尽管陨石上栖息着微生物，但微生物种群不太可能与它们掉落的周围土壤的群落相匹配。
Finding fresh, sterilized rocks provides ecologists with a clean slate to test ideas about first colonization and the evolution of soils de novo. Lava has been used previously in first colonizer studies due to the sterilizing heat required for its formation. However, fresh lava typically falls upon older volcanic successions of similar chemistry and modal mineral abundance. Given enough time, this results in the development of similar microbial communities in the newly erupted lava due to a lack of contrast between the new and old substrates. Meteorites, which are sterile when they fall to Earth, provide such contrast because their reduced and mafic chemistry commonly differs to the surfaces on which they land; thus allowing investigation of how community membership and structure respond to this new substrate over time. We conducted 16S rRNA gene analysis on meteorites and soil from the Nullarbor Plain, Australia. We found that the meteorites have low species richness and evenness compared to soil sampled from directly beneath each meteorite. Despite the meteorites being found kilometers apart, the community structure of each meteorite bore more similarity to those of other meteorites (of similar composition) than to the community structure of the soil on which it resided. Meteorites were dominated by sequences that affiliated with the Actinobacteria with the major Operational Taxonomic Unit (OTU) classified as Rubrobacter radiotolerans. Proteobacteria and Bacteroidetes were the next most abundant phyla. The soils were also dominated by Actinobacteria but to a lesser extent than the meteorites. We also found OTUs affiliated with iron/sulfur cycling organisms Geobacter spp. and Desulfovibrio spp. This is an important finding as meteorites contain abundant metal and sulfur for use as energy sources. These ecological findings demonstrate that the structure of the microbial community in these meteorites is controlled by the substrate, and will not reach homeostasis with the Nullarbor community, even after ca. 35,000 years. Our findings show that meteorites provide a unique, sterile substrate with which to test ideas relating to first-colonizers. Although meteorites are colonized by microorganisms, the microbial population is unlikely to match the community of the surrounding soil on which they fall.
影响因子：
4.2
作者：
David Van Horn;C. Wolf;D. Colman;Xiaoben Jiang;T. Kohler;D. McKnight;L. Stanish;Terrill Yazzie;C. Takacs-Vesbach
通讯作者：
David Van Horn;C. Wolf;D. Colman;Xiaoben Jiang;T. Kohler;D. McKnight;L. Stanish;Terrill Yazzie;C. Takacs-Vesbach
影响因子：
3.3
作者：
L. Excoffier;P. Smouse;J. Quattro
通讯作者：
L. Excoffier;P. Smouse;J. Quattro