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Abstract EANA2026-239 |
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Antarctic englacial microbiomes as analogues of icy worlds: integrating microbial diversity and functional potential
Discoveries from planetary missions across the Solar System, coupled with research on terrestrial extreme environments, have greatly expanded the concept of habitability. Given that many potentially habitable planetary bodies are characterized by permanently low temperatures, defining the lower thermal limit for life remains a central question in astrobiology. In this context, Antarctic glaciers and ice sheets serve as ideal terrestrial analogues for these icy worlds, exposing microbial communities to severe conditions such as subzero temperatures, limited liquid water, high radiation, and nutrient scarcity.
To understand their diversity and adaptive strategies, this study integrates taxonomic and metaproteomic analyses of microbial communities from two Antarctic glaciers in the South Shetland Islands: Mount Pond (Deception Island, a volcanically active zone) and Quito (Greenwich Island).
Sequencing revealed a highly diverse microbial community comprising psychrophilic and psychrotolerant species, alongside thermophilic microorganisms linked to volcanic activity. Complementarily, metaproteomic profiling identified key proteins involved in energy metabolism, nutrient transport, protein synthesis, and stress response, providing concrete evidence of cellular activity at subzero temperatures. These findings demonstrate that glacial microorganisms are not merely quiescent, but maintain an active metabolism and play a functional role within glacial ecosystems. Ultimately, this work establishes a baseline model to evaluate the viability of life under the physicochemical conditions representative of extraterrestrial cryogenic environments.
Garcia-Lopez, E., & Cid, C. (2017). Glaciers and ice sheets as analog environments of potentially habitable icy worlds. Front. Microbiol. 8, 1407.
Martinez-Alonso, E., Pena-Perez, S., Serrano, S., Garcia-Lopez, E., Alcazar, A., & Cid, C. (2019). Taxonomic and functional characterization of a microbial community from a volcanic englacial ecosystem in Deception Island, Antarctica. Scientific reports, 9(1), 12158.
García-Lopez, E., Serrano, S., Calvo, M. A., Peña Perez, S., Sanchez-Casanova, S., García-Descalzo, L., & Cid, C. (2021). Microbial Community Structure Driven by a Volcanic Gradient in Glaciers of the Antarctic Archipelago South Shetland. Microorganisms 2021, 9, 392.