20-EPN-083: Beyond Antarctica: a survey on detection of life in endolithic fossils supporting future space exploration missions
Visit by Federico Biagioli, University of Tuscia (Italy) to TA2.19 Center for Microbial Life Detection, Medical University Graz (Austria).
Dates of visit: 14-20 November 2021 (in person visit), 21-26 April 2022 (remote analysis)
Report Summary: Endolithic growth is the ultimate microbial adaptation and the predominant life-form in the far extreme ice-free areas of Antarctic deserts, considered among of the best analogues of the Martian environment on Earth. Although recent molecular studies have started to shed light on the biodiversity, distribution and composition of crypto-endolithic communities in visibly colonized rock samples, fossilized or apparently not colonized endolithic communities remain largely unexplored. Amplicon-sequencing analysis of fungal and prokaryotic domains on both not colonized and fossil samples were here performed to gain information about preservation of extinct life traces within rock and evidences of possible life detection also in eventual extra-terrestrial samples. Genomic DNA was extracted and sequenced from 24 fossil and 6 apparently not colonized rocky samples, resulting in a high number of reads and mapped ASVs for fungal (657,626 quality- filtered reads and 161 ASVs), bacterial 16S rDNA (1,296,594 reads mapped into 839 ASVs) and 16S archaeal specific (2,813,402 validated clustered in 3,514 ASVs) datasets. The high number of reads and ASVs achieved allows us to suppose that rocks not only represent a perfect refuge from harsh external environmental conditions, but also an important preservation ark for biosignatures of past life forms.
Read the full scientific report with kind permission of Federico Biagioli
