Metabolomics of Dry Versus Reanimated Antarctic Lichen-Dominated Endolithic Communities

Abstract

Cryptoendolithic communities are almost the sole life form in the ice-free areas of the Antarctic desert, encompassing among the most extreme-tolerant organisms known on Earth that still assure ecosystems functioning, regulating nutrient and biogeochemical cycles under conditions accounted as incompatible with active life. If high-throughput sequencing based studies are unravelling prokaryotic and eukaryotic diversity, they are not yet characterized in terms of stress adaptations and responses, despite their paramount ecological importance. In this study, we compared the responses of Antarctic endolithic communities, with special focus on fungi, both under dry conditions (i.e., when dormant), and after reanimation by wetting, light, and optimal temperature (15 °C). We found that several metabolites were differently expressed in reanimated opposite sun exposed communities, suggesting a critical role in their success. In particular, the saccharopine pathway was up-regulated in the north surface, while the spermine/spermidine pathway was significantly down-regulated in the shaded exposed communities. The carnitine-dependent pathway is up-regulated in south-exposed reanimated samples, indicating the preferential involvement of the B-oxidation for the functioning of TCA cycle. The role of these metabolites in the performance of the communities is discussed herein.

Antarctic Soil Metabolomics: A Pilot Study

“…In addition, Coleine et al [13] and Fanelli et al [14] reported two examples of MS-based analyses of microbial communities colonising Antarctic rocks, comparing the metabolic responses of Antarctic endolithic communities when dormant, and after reanimation by wetting, light, and optimal temperature. NMR spectroscopy allowed for metabolomic analysis of soils from agricultural systems or native soils.…”

Metabolomic Profile of the Fungus Cryomyces antarcticus Under Simulated Martian and Space Conditions as Support for Life-Detection Missions on Mars

“…Recently metabolomics was successfully applied to Antarctic cryptoendolithic lichen-dominated communities, defining their adaptation strategies to survive in these harshest conditions. For this reason, metabolomics become a powerful tool to study life in extreme environments ( Coleine et al, 2020 ; Fanelli et al, 2021 ). Here, this approach allows us to investigate (i) which fungal biomolecule maintains their stability after exposure to SVTs, and (ii) the effects of the interactions of two Martian regolith analogues on fungal growth as well as during dehydration processes.…”

Rocks support a distinctive and consistent mycobiome across contrasting dry regions of Earth

“…For example, lichenized fungi, rock-inhabiting microcolonial fungi (RIF) and yeasts are considered rock specialists and are commonly retrieved from different rock substrates (e.g. Fanelli et al 2021, Choe et al 2021, Ertekin et al 2021). Yet, whether a consistent membership of these rock-associated fungi exists across different biomes and continents is still undetermined .…”