Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota
Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota
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瑟特西不同表层土壤类型中的微生物定殖及其地下微生物群的多样性分析
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Ólafsson
中科院分区：
文献类型：
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作者：
V. Marteinsson;A. Klonowski;E. Reynisson;P. Vannier;B. Sigurdsson;M. Ólafsson
抽象的。自 50 年前该岛形成以来，人们就已经系统地观察到瑟特西岛的生命殖民活动。尽管第一批殖民者是原核生物，例如细菌和蓝绿藻，但大多数研究都集中在植物和动物的定居上，而很少关注微生物的演替。为了探索不同土壤中的微生物定殖以及相关植被和鸟类对环境细菌数量的影响，我们从岛屿表面不同的土壤类型中收集了 45 个样本。在22、30和37℃下对所有土壤样品采用平板计数法进行总活菌计数，并测量有机质和氮（N）的量。还对选定的样品进行了大肠菌群、粪便大肠菌群以及需氧和厌氧细菌的检测。通过使用特殊采样器从 181 m 钻孔中采集液体地下样本来研究地下生物圈。通过16S rRNA基因序列分析和培养对样品中未培养生物群进行多样性分析。观察到养分缺乏与表层土壤样品中微生物数量之间的相关性。在几乎纯的浮石中检测到的细菌数量最低（1 × 104–1 × 105 个细胞 g−1），但在植被土壤或带有鸟粪的浮石中，细菌数量明显较高（1 × 106–1 × 109 个细胞 g−1）。粪便细菌的数量还与细菌总数和土壤类型相关。仅在植物样本和含有鸟粪的样本中检测到属于肠杆菌科的细菌。任何样本中均未发现人类病原体沙门氏菌、弯曲杆菌和李斯特菌。在 80 和 54 °C 下 145 和 172 m 深度采集的地下样品中分别发现了嗜热细菌和古细菌 16S rDNA 序列，但在富集过程中未观察到生长。微生物群序列通常与任何已知的 16S rRNA 基因序列的关联性较低。
Abstract. Colonization of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue–green algae, most studies have been focused on the settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse soils and the influence of associated vegetation and birds on numbers of environmental bacteria, we collected 45 samples from different soil types on the surface of the island. Total viable bacterial counts were performed with the plate count method at 22, 30 and 37 °C for all soil samples, and the amount of organic matter and nitrogen (N) was measured. Selected samples were also tested for coliforms, faecal coliforms and aerobic and anaerobic bacteria. The subsurface biosphere was investigated by collecting liquid subsurface samples from a 181 m borehole with a special sampler. Diversity analysis of uncultivated biota in samples was performed by 16S rRNA gene sequences analysis and cultivation. Correlation was observed between nutrient deficits and the number of microorganisms in surface soil samples. The lowest number of bacteria (1 × 104–1 × 105 cells g−1) was detected in almost pure pumice but the count was significantly higher (1 × 106–1 × 109 cells g−1) in vegetated soil or pumice with bird droppings. The number of faecal bacteria correlated also to the total number of bacteria and type of soil. Bacteria belonging to Enterobacteriaceae were only detected in vegetated samples and samples containing bird droppings. The human pathogens Salmonella, Campylobacter and Listeria were not in any sample. Both thermophilic bacteria and archaea 16S rDNA sequences were found in the subsurface samples collected at 145 and 172 m depth at 80 and 54 °C, respectively, but no growth was observed in enrichments. The microbiota sequences generally showed low affiliation to any known 16S rRNA gene sequences.