Geology and elevation shape bacterial assembly in Antarctic endolithic communities

Journal Article · 27 October 2023 · Science of the Total Environment

DOI: https://doi.org/10.1016/j.scitotenv.2023.168050 · OSTI ID:2331389

Larsen, Stefano ^[1]; Coleine, Claudia ^[2]; Albanese, Davide ^[1]; Stegen, James C.  ^[3]; Selbmann, Laura  ^[2]; Donati, Claudio ^[4]

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1. Fondazione Edmund Mach, San Michele all’Adige (Italy)
2. University of Tuscia, Viterbo (Italy)
3. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
4. Fondazione Edmund Mach, San Michele all’Adige (Italy); Italian Antarctic National Museum (MNA), Genoa (Italy)

Ice free areas of continental Antarctica are among the coldest and driest environments on Earth, and yet, they support surprisingly diverse and highly adapted microbial communities. Endolithic growth is one of the key adaptations to such extreme environments and often represents the dominant life-form. Despite growing scientific interest, little is known of the mechanisms that influence the assembly of endolithic microbiomes across these harsh environments. Here, we used metagenomics to examine the diversity and assembly of endolithic bacterial communities across Antarctica within different rock types and over a large elevation range. While granite supported richer and more heterogeneous communities than sandstone, elevation had no apparent effect on taxonomic richness, regardless of rock type. Conversely, elevation was clearly associated with turnover in community composition, with the deterministic process of variable selection driving microbial assembly along the elevation gradient. The turnover associated with elevation was modulated by geology, whereby for a given elevation difference, turnover was consistently larger between communities inhabiting different rock types. Overall, selection imposed by elevation and geology appeared stronger than turnover related to other spatially-structured environmental drivers. Our findings indicate that at the cold-arid limit of life on Earth, geology and elevation are key determinants of endolithic bacterial heterogeneity. This also suggests that warming temperatures may threaten the persistence of such extreme-adapted organisms.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE; European Commission; Italian Antarctic National Museum (MNA)
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 2331389
• Report Number(s): PNNL-SA--196817
• Journal Information: Science of the Total Environment, Journal Name: Science of the Total Environment Vol. 907; ISSN 0048-9697
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English