Baeza Marcelo, Barahona Salvador, Alcaíno Jennifer, Cifuentes Víctor
Laboratorio de Genética, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
Front Microbiol. 2017 Nov 14;8:2235. doi: 10.3389/fmicb.2017.02235. eCollection 2017.
In cold environments such as polar regions, microorganisms play important ecological roles, and most of our knowledge about them comes from studies of cultivable microorganisms. Metagenomic technologies are powerful tools that can give a more comprehensive assessment of microbial communities, and the amplification of rDNA followed by next-generation sequencing has given good results in studies aimed particularly at environmental microorganisms. Culture-independent studies of microbiota in terrestrial habitats of Antarctica, which is considered the driest, coldest climate on Earth, are increasing and indicate that micro-diversity is much higher than previously thought. In this work, the microbial diversity of terrestrial habitats including eight islands of the South Shetland Archipelago, two islands on the Antarctic Peninsula and Union Glacier, was studied by amplicon-metagenome analysis. Molecular analysis of the studied localities clustered together the islands of the South Shetland Archipelago, except Greenwich Island, and separated them from the Litchfield and Lagotellerie islands and Union Glacier, which is in agreement with the latitudinal difference among them. Among fungi, 87 genera and 123 species were found, of which species belonging to 37 fungal genera not previously cultivated from Antarctica were detected. Phylogenetic analysis, including the closest BLAST-hit sequences, clustered fungi in 11 classes being the most represented Lecanoromycetes and Eurotiomycetes.
在极地地区等寒冷环境中，微生物发挥着重要的生态作用，而我们对它们的了解大多来自对可培养微生物的研究。宏基因组技术是强大的工具，能够对微生物群落进行更全面的评估，通过对核糖体DNA（rDNA）进行扩增并随后进行新一代测序，在针对环境微生物的研究中取得了良好成果。对被认为是地球上最干燥、最寒冷气候的南极洲陆地栖息地微生物群进行的非培养研究正在增加，这表明微观多样性比以前认为的要高得多。在这项工作中，通过扩增子宏基因组分析研究了包括南设得兰群岛的八个岛屿、南极半岛的两个岛屿以及联合冰川在内的陆地栖息地的微生物多样性。对所研究地点的分子分析将南设得兰群岛的岛屿（除格林威治岛外）聚集在一起，并将它们与利奇菲尔德岛、拉戈泰勒里岛以及联合冰川区分开来，这与它们之间的纬度差异一致。在真菌中，发现了87个属和123个物种，其中检测到了37个以前未从南极洲培养出的真菌属的物种。系统发育分析（包括最接近的BLAST比对序列）将真菌聚类为11个纲，其中最具代表性的是茶渍纲和散囊菌纲。
