MIcrobial Diversity within the Vicinity of the Concordia Antarctic Station

The Concordia Research Station provides a unique location for preparatory activities for future human journey to Mars, to explore microbial diversity at subzero temperatures and monitor the dissemination of human-associated microorganisms within the pristine surrounding environment.

The present study was performed in the frame of the BacFinder project (European Space Agency, ESA AO-13-Concordia) with the aim to unravel the environmental- and human-associated microbial diversity in the surrounding of the Concordia Station. This is the first intensive and extensive surface snow sampling performed monthly over a two-year period at three distances (10, 500, and 1000 m) from the Concordia Station, and investigated by a high-throughput sequencing approach. Emphasis was laid on the relation between microbial presence and both seasonality and distance from the Base. Data suggested that if present the anthropogenic impact was below the detection limit of the employed DNA sequencing-based techniques. On the other hand, our study corroborated the use of DNA sequencing for revealing microbial presence in remote and hostile environments, with implications for Planetary Protections and for life-detection in astrobiology relevant targets.

A comprehensive analysis of the biodiversity in the snow/ice samples will be carried out by using molecular biology (cultivation-independent) techniques combined to bioinformatics tools. Attention will be given to the genetic diversity of bacteria, cyanobacteria and fungi in the surrounding areas of Concordia station.

The microbial community structure and genetic diversity will be characterized by amplification of ribosomal genes and metagenomics assay.

This approach will allow to : i) determine the microbial diversity outside the Concordia station, (ii) evaluate the influence on the microbial diversity of the environmental conditions, (iii) assess the anthropogenic impact from the Concordia station on the pristine Antarctic environment, and (iv) model the microbial dynamics.

Results will provide new insights into the Antarctic microbial biodiversity within the vicinity of the Concordia Station, and, by integrating the results with microclimatic data, will contribute to a better understanding of the structure and dynamics of the microbial communities with implications when monitoring and predicting climate change effects.

This proposal will contribute to the use of results of projects aimed at assessing the role of aerial dispersal in shaping the patterns of biodiversity in Antarctica. In addition, it will contribute to achieve an integrated knowledge of the microbial diversity in Antarctica, being complementary for investigated areas and colonized substrata to the proposed proposals MDV-MICRO (PI S. Ventura), AMunDsEN (PI L. Selbmann) e PermEco (PI M. Guglielmin).

Finally, given that Earth’s frozen polar regions are considered analogues of near-surface environments of Mars and of the Jupiter’s icy moon Europa, the results of this proposal will be relevant for astrobiology research programs aimed at searching life beyond Earth.

Amplicon sequencing was leveraged to investigate the microbial diversity of surface snow samples collected monthly over a two-year period, at three distances from the Station (10, 500, and 1000 m). Even when the extracted total DNA was below the detection limit, 16S rRNA gene sequencing was successfully performed on all samples, while 18S rRNA was amplified on 19 samples out of 51. No significant relationships were observed between microbial diversity and seasonality (summer or winter) or distance from the Concordia base. This suggested that if present the anthropogenic impact should have been below the detectability limit. Nevertheless, our study corroborated the use of DNA sequencing-based techniques for revealing microbial presence in remote and hostile environments, with implications for Planetary Protections during space missions and for life-detection in astrobiology relevant targets. 

1.XIIthSCAR Biology Symposium, 10-14 July 2017, Leuven, Belgium. ”Unravelling the secret of the resistance of desert strains of Chroococcidiopsis”. Billi D, Fagliarone C, Verseux C,Mosca C, Baqu ́e M, WilmotteA. 

2.COST Workshop Life and Origin, 19-23 March 2017,Bertinoro, Italy. “Desert cyanobacteria under space and planetary simulations: towards the limits of life”. Billi D. 

3.JGI User Meeting, 02-05 April, 2019, San Francisco, CA. “A first metagenomic survey into the cryptoendolithiccommunities of the ice-free areas along the Victoria Land, Continental Antarctica”. Coleine C, Stajich JE, Donati C, Albanese D, Zucconi L,Onofri S., Selbmann L. 

4.JGI User Meeting, 02-05 April, 2019, San Francisco, CA. “A Comparative genomics provides in- sights into thelifestyle of Antarctic cryptoendolithic black fungi”. Coleine C, Stajich JE, Masonjiones S, Zucconi L,Onofri S., Selbmann L.

5.18th Congress of European Mycologists, 16-21 September 2019, Warsaw, Poland. “Newtaxa of Antarctic cryptoendolithic black fungi by multi locus phylogeny”. Selbmann L, Mostardi F, Coleine C, Zucconi L, Onofri S. 

6.18th Congress of European Mycologists, 16-21 September 2019, Warsaw, Poland. ”Comparative genomics, evolution and adaptation of Antarcticcryptoendolithic Black Fungi. Selbmann L, Mostardi F, Coleine C, Zucconi L, Onofri S. 

7. International J. Astrobiology 2019. Desert cyanobacteria under space and planetary simulations: a tool for searching for life beyond Earth and supporting human space exploration. Billi D.