Seasonality Is the Main Determinant of Microbial Diversity Associated to Snow/Ice around Concordia Station on the Antarctic Polar Plateau

The French–Italian Concordia Research Station, situated on the Antarctic Polar Plateau at an elevation of 3233 m above sea level, offers a unique opportunity to study the presence and variation of microbes introduced by abiotic or biotic vectors and, consequently, appraise the amplitude of human impact in such a pristine environment. This research built upon a previous work, which explored microbial diversity in the surface snow surrounding the Concordia Research Station. While that study successfully characterized the bacterial assemblage, detecting fungal diversity was hampered by the low DNA content. To address this knowledge gap, in the present study, we optimized the sampling by increasing ice/snow collected to leverage the final DNA yield. The V4 variable region of the 16S rDNA and Internal Transcribed Spacer (ITS1) rDNA was used to evaluate bacterial and fungal diversity. From the sequencing, we obtained 3,352,661 and 4,433,595 reads clustered in 930 and 3182 amplicon sequence variants (ASVs) for fungi and bacteria, respectively. Amplicon sequencing revealed a predominance of Basidiomycota (49%) and Ascomycota (42%) in the fungal component; Bacteroidota (65.8%) is the main representative among the bacterial phyla. Basidiomycetes are almost exclusively represented by yeast-like fungi. Our findings provide the first comprehensive overview of both fungal and bacterial diversity in the Antarctic Polar Plateau’s surface snow/ice near Concordia Station and to identify seasonality as the main driver of microbial diversity; we also detected the most sensitive microorganisms to these factors, which could serve as indicators of human impact in this pristine environment and aid in planetary protection for future exploration missions.

[1]  L. Selbmann,et al.  Snow Surface Microbial Diversity at the Detection Limit within the Vicinity of the Concordia Station, Antarctica , 2022, Life.

[2]  R. Edelmann,et al.  Physiological and Genomic Characterization of Two Novel Bacteroidota Strains Asinibacterium spp. OR43 and OR53 , 2022, Bacteria.

[3]  S. Onofri,et al.  Antarctica as a reservoir of planetary analogue environments , 2021, Extremophiles.

[4]  P. Ramachandran,et al.  Microbiomes of commercially-available pine nuts and sesame seeds , 2021, PloS one.

[5]  S. Tringe,et al.  Pre-Cambrian roots of novel Antarctic cryptoendolithic bacterial lineages , 2021, Microbiome.

[6]  Xiangzhen Li,et al.  microeco: An R package for data mining in microbial community ecology. , 2020, FEMS microbiology ecology.

[7]  H. Peres,et al.  Oxidative status and intestinal health of gilthead sea bream (Sparus aurata) juveniles fed diets with different ARA/EPA/DHA ratios , 2020, Scientific Reports.

[8]  W. Shen,et al.  Variation in Near-Surface Airborne Bacterial Communities among Five Forest Types , 2020, Forests.

[9]  T. Vogel,et al.  Microbial composition in seasonal time series of free tropospheric air and precipitation reveals community separation , 2019, Aerobiologia.

[10]  J. Stajich,et al.  Sun Exposure Shapes Functional Grouping of Fungi in Cryptoendolithic Antarctic Communities , 2018, Life.

[11]  Jonathan M Palmer,et al.  Non-biological synthetic spike-in controls and the AMPtk software pipeline improve mycobiome data , 2018, PeerJ.

[12]  N. Gunde-Cimerman,et al.  Cystobasidium alpinum sp. nov. and Rhodosporidiobolus oreadorum sp. nov. from European Cold Environments and Arctic Region , 2018, Life.

[13]  Jianping Huang,et al.  Characterization of atmospheric bioaerosols along the transport pathway of Asian dust during the Dust-Bioaerosol 2016 Campaign , 2017 .

[14]  M. Tsuji,et al.  Cystobasidium tubakii and Cystobasidium ongulense, new basidiomycetous yeast species isolated from East Ongul Island, East Antarctica , 2017 .

[15]  P. Dhakephalkar,et al.  Microbial communities associated with Antarctic snow pack and their biogeochemical implications. , 2016, Microbiological research.

[16]  Ben Nichols,et al.  VSEARCH: a versatile open source tool for metagenomics , 2016, PeerJ.

[17]  P. Convey,et al.  Aerobiology Over Antarctica – A New Initiative for Atmospheric Ecology , 2016, Front. Microbiol..

[18]  L. Dartnell,et al.  Isolation of Radiation-Resistant Bacteria from Mars Analog Antarctic Dry Valleys by Preselection, and the Correlation between Radiation and Desiccation Resistance. , 2015, Astrobiology.

[19]  P. Convey,et al.  Emerging spatial patterns in Antarctic prokaryotes , 2015, Front. Microbiol..

[20]  Tanja S. Maier,et al.  Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories , 2014, Ecology and evolution.

[21]  Kabir G. Peay,et al.  Sequence Depth, Not PCR Replication, Improves Ecological Inference from Next Generation DNA Sequencing , 2014, PloS one.

[22]  G. Diolaiuti,et al.  Influence of abiotic variables on culturable yeast diversity in two distinct Alpine glaciers. , 2013, FEMS microbiology ecology.

[23]  R. Chávez,et al.  Rhodotorula portillonensis sp. nov., a basidiomycetous yeast isolated from Antarctic shallow-water marine sediment. , 2013, International journal of systematic and evolutionary microbiology.

[24]  M. Trujillo,et al.  Asinibacterium lactis gen. nov., sp. nov., a member of the family Chitinophagaceae, isolated from donkey (Equus asinus) milk. , 2013, International journal of systematic and evolutionary microbiology.

[25]  Susan Holmes,et al.  phyloseq: An R Package for Reproducible Interactive Analysis and Graphics of Microbiome Census Data , 2013, PloS one.

[26]  A. Salamov,et al.  Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Dothideomycetes Fungi , 2012, PLoS pathogens.

[27]  B. Turchetti,et al.  Psychrophilic yeasts from worldwide glacial habitats: diversity, adaptation strategies and biotechnological potential. , 2012, FEMS microbiology ecology.

[28]  L. Michaud,et al.  Predominance of Flavobacterium, Pseudomonas, and Polaromonas within the prokaryotic community of freshwater shallow lakes in the northern Victoria Land, East Antarctica. , 2012, FEMS microbiology ecology.

[29]  Susan M. Huse,et al.  Defining seasonal marine microbial community dynamics , 2011, The ISME Journal.

[30]  V. Romanovskaya,et al.  [Resistance of Antarctic microorganisms to UV radiation]. , 2011, Mikrobiolohichnyi zhurnal.

[31]  J. Sampaio,et al.  Cystobasidiomycetes yeasts from Patagonia (Argentina): description of Rhodotorula meli sp. nov. from glacial meltwater. , 2010, International journal of systematic and evolutionary microbiology.

[32]  William A. Walters,et al.  QIIME allows analysis of high-throughput community sequencing data , 2010, Nature Methods.

[33]  Patrick De Boever,et al.  Evaluation of the Airborne Bacterial Population in the Periodically Confined Antarctic Base Concordia , 2009, Microbial Ecology.

[34]  V. Miteva,et al.  Phylogenetic and Physiological Diversity of Microorganisms Isolated from a Deep Greenland Glacier Ice Core , 2004, Applied and Environmental Microbiology.

[35]  W. F. Thompson,et al.  Rapid isolation of high molecular weight plant DNA. , 1980, Nucleic acids research.

[36]  L. Selbmann,et al.  Taxonomic and phenotypic characterization of yeasts isolated from worldwide cold rock-associated habitats. , 2014, Fungal biology.

[37]  S. Shivaji,et al.  Antarctic ice core samples: culturable bacterial diversity. , 2013, Research in microbiology.

[38]  P. Ariya,et al.  Organics in environmental ices: sources, chemistry, and impacts , 2012, Atmospheric Chemistry and Physics.

[39]  R. Knight,et al.  Global patterns in the biogeography of bacterial taxa. , 2011, Environmental microbiology.

[40]  Robert C. Edgar,et al.  Search and clustering orders of magnitude faster than BLAST , 2010 .

[41]  M. Piepenbring,et al.  Diversity, phylogeny and classification of basidiomycetous yeasts. , 2004 .