The ice-free McMurdo Dry Valleys of Antarctica are dominated by nutrient-poor mineral soil and rocky outcrops. The principal habitat for microorganisms is within rocks (endolithic). In this environment, microorganisms are provided with protection against sub-zero temperatures, rapid thermal fluctuations, extreme dryness, and ultraviolet and solar radiation. Endolithic communities include lichen, algae, fungi, and a diverse array of bacteria. Chloroflexota is among the most abundant bacterial phyla present in these communities. Among the Chloroflexota are four novel classes of bacteria, here named Candidatus Spiritibacteria class. nov. (=UBA5177), Candidatus Martimicrobia class. nov. (=UBA4733), Candidatus Tarhunnaeia class. nov. (=UBA6077), and Candidatus Uliximicrobia class. nov. (=UBA2235). We retrieved 17 high-quality metagenome-assembled genomes (MAGs) that represent these four classes. Based on genome predictions, all these bacteria are inferred to be aerobic heterotrophs that encode enzymes for the catabolism of diverse sugars. These and other organic substrates are likely derived from lichen, algae, and fungi, as metabolites (including photosynthate), cell wall components, and extracellular matrix components. The majority of MAGs encode the capacity for trace gas oxidation using high-affinity uptake hydrogenases, which could provide energy and metabolic water required for survival and persistence. Furthermore, some MAGs encode the capacity to couple the energy generated from H 2 and CO oxidation to support carbon fixation (atmospheric chemosynthesis). All encode mechanisms for the detoxification and efflux of heavy metals. Certain MAGs encode features that indicate possible interactions with other organisms, such as Tc-type toxin complexes, hemolysins, and macroglobulins.
IMPORTANCEThe ice-free McMurdo Dry Valleys of Antarctica are the coldest and most hyperarid desert on Earth. It is, therefore, the closest analog to the surface of the planet Mars. Bacteria and other microorganisms survive by inhabiting airspaces within rocks (endolithic). We identify four novel classes of phylum Chloroflexota , and, based on interrogation of 17 metagenome-assembled genomes, we predict specific metabolic and physiological adaptations that facilitate the survival of these bacteria in this harsh environment\uffe2\uff80\uff94including oxidation of trace gases and the utilization of nutrients (including sugars) derived from lichen, algae, and fungi. We propose that such adaptations allow these endolithic bacteria to eke out an existence in this cold and extremely dry habitat.
", "keywords": ["570", "Bacteria", "Fungi", "Antarctic Regions", "Chloroflexi", "15. Life on land", "Survival strategies", "Cold Temperature", "Extremophiles", "13. Climate action", "Antarctica", "Endolithic communities", "Metagenomics", "14. Life underwater", "Sugars", "Settore BIO/19 - MICROBIOLOGIA GENERALE"]}, "links": [{"href": "https://doi.org/10.1128/aem.02264-23"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Applied%20and%20Environmental%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1128/aem.02264-23", "name": "item", "description": "10.1128/aem.02264-23", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1128/aem.02264-23"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-02-19T00:00:00Z"}}, {"id": "10.1002/ecy.2137", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:13:54Z", "type": "Journal Article", "created": "2018-01-10", "title": "Ecological drivers of soil microbial diversity and soil biological networks in the Southern Hemisphere", "description": "AbstractThe ecological drivers of soil biodiversity in the Southern Hemisphere remain underexplored. Here, in a continental survey comprising 647 sites, across 58 degrees of latitude between tropical Australia and Antarctica, we evaluated the major ecological patterns in soil biodiversity and relative abundance of ecological clusters within a co\uffe2\uff80\uff90occurrence network of soil bacteria, archaea and eukaryotes. Six major ecological clusters (modules) of co\uffe2\uff80\uff90occurring soil taxa were identified. These clusters exhibited strong shifts in their relative abundances with increasing distance from the equator. Temperature was the major environmental driver of the relative abundance of ecological clusters when Australia and Antarctica are analyzed together. Temperature, aridity, soil properties and vegetation types were the major drivers of the relative abundance of different ecological clusters within Australia. Our data supports significant reductions in the diversity of bacteria, archaea and eukaryotes in Antarctica vs. Australia linked to strong reductions in temperature. However, we only detected small latitudinal variations in soil biodiversity within Australia. Different environmental drivers regulate the diversity of soil archaea (temperature and soil carbon), bacteria (aridity, vegetation attributes and pH) and eukaryotes (vegetation type and soil carbon) across Australia. Together, our findings provide new insights into the mechanisms driving soil biodiversity in the Southern Hemisphere.Because of severe abiotic limitations, Antarctic soils represent simplified systems, where microorganisms are the principal drivers of nutrient cycling. This relative simplicity makes these ecosystems particularly vulnerable to perturbations, like global warming, and the Antarctic Peninsula is among the most rapidly warming regions on the planet. However, the consequences of the ongoing warming of Antarctica on microorganisms and the processes they mediate are unknown. Here, using 16S rRNA gene pyrosequencing and qPCR, we report highly consistent responses in microbial communities across disparate sub-Antarctic and Antarctic environments in response to 3 years of experimental field warming (+0.5 to 2 \uffc2\uffb0C). Specifically, we found significant increases in the abundance of fungi and bacteria and in the Alphaproteobacteria-to-Acidobacteria ratio, which could result in an increase in soil respiration. Furthermore, shifts toward generalist bacterial communities following warming weakened the linkage between the bacterial taxonomic and functional richness. GeoChip microarray analyses also revealed significant warming effects on functional communities, specifically in the N-cycling microorganisms. Our results demonstrate that soil microorganisms across a range of sub-Antarctic and Antarctic environments can respond consistently and rapidly to increasing temperatures.
", "keywords": ["0301 basic medicine", "Climate Change", "Antarctic Regions", "global warming", "open-top chambers", "Soil", "03 medical and health sciences", "RNA", " Ribosomal", " 16S", "carbon cycle", "nitrogen cycle", "SDG 13 - Climate Action", "SDG 14 - Life Below Water", "14. Life underwater", "Soil Microbiology", "0303 health sciences", "Bacteria", "GeoChip microarrays", "Fungi", "Temperature", "Nitrogen Cycle", "15. Life on land", "Microarray Analysis", "Biota", "13. Climate action", "international", "Antarctica"]}, "links": [{"href": "https://doi.org/10.1038/ismej.2011.124"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/The%20ISME%20Journal", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1038/ismej.2011.124", "name": "item", "description": "10.1038/ismej.2011.124", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1038/ismej.2011.124"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2011-09-22T00:00:00Z"}}, {"id": "10.1089/ast.2022.0062", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:18:16Z", "type": "Journal Article", "created": "2023-02-22", "title": "Rock Traits Drive Complex Microbial Communities at the Edge of Life", "description": "Antarctic deserts are among the driest and coldest ecosystems of the planet; there, some microbes survive under these extreme conditions inside porous rocks, forming the so-called endolithic communities. Yet the contribution of distinct rock traits to support complex microbial assemblies remains poorly determined. Here, we combined an extensive Antarctic rock survey with rock microbiome sequencing and ecological networks and found that contrasting combinations of microclimatic and rock traits such as thermal inertia, porosity, iron concentration, and quartz cement can help explain the multiple complex microbial assemblies found in Antarctic rocks. Our work highlights the pivotal role of rocky substrate heterogeneity in sustaining contrasting groups of microorganisms, which is essential to understand life at the edge on Earth and for the search for life on other rocky planets such as Mars.", "keywords": ["570", "Earth", " Planet", "Habitability", "500", "Antarctica; Extremophiles; Biogeochemistry; Habitability; Astrobiology; Terrestrial analog;", "Planets", "Antarctic Regions", "Biogeochemistry", "15. Life on land", "Astrobiology", "Extremophiles", "Terrestrial analog", "13. Climate action", "Exobiology", "Antarctica", "14. Life underwater", "Settore BIO/19 - MICROBIOLOGIA GENERALE", "Ecosystem"]}, "links": [{"href": "https://doi.org/10.1089/ast.2022.0062"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Astrobiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1089/ast.2022.0062", "name": "item", "description": "10.1089/ast.2022.0062", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1089/ast.2022.0062"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2023-04-01T00:00:00Z"}}, {"id": "10.3389/feart.2020.00229", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:20:39Z", "type": "Journal Article", "created": "2020-06-26", "title": "Silicon Isotopes Reveal a Non-glacial Source of Silicon to Crescent Stream, McMurdo Dry Valleys, Antarctica", "description": "In high latitude environments, silicon is supplied to river waters by both glacial and non-glacial chemical weathering. The signal of these two end-members is often obscured by biological uptake and/or groundwater input in the river catchment. McMurdo Dry Valleys streams in Antarctica have no deep groundwater input, no connectivity between streams and no surface vegetation cover, and thus provide a simplified system for us to constrain the supply of dissolved silicon (DSi) to rivers from chemical weathering in a glacial environment. Here we report dissolved Si concentrations, germanium/silicon ratios (Ge/Si) and silicon isotope compositions (\u03b430SiDSi) in Crescent Stream, McMurdo Dry Valleys for samples collected between December and February in the 2014\u22122015, 2015\u22122016, and 2016\u22122017 austral seasons. The \u03b430SiDSi compositions and DSi concentrations are higher than values reported in wet-based glacial meltwaters, and form a narrow cluster within the range of values reported for permafrost dominated Arctic Rivers. High \u03b430SiDSi compositions, ranging from +0.90\u2030 to +1.39\u2030, are attributed to (i) the precipitation of amorphous silica during freezing of waters in isolated pockets of the hyporheic zone in the winter and the release of Si from unfrozen pockets during meltwater-hyporheic zone exchange in the austral summer, and (ii) additional Si isotope fractionation via long-term Si uptake in clay minerals and seasonal Si uptake into diatoms superimposed on this winter-derived isotope signal. There is no relationship between \u03b430SiDSi compositions and DSi concentrations with seasonal and daily discharge, showing that stream waters contain DSi that is in equilibrium with the formation of secondary Si minerals in the hyporheic zone. We show that \u03b430SiDSi compositions can be used as tracers of silicate weathering in the hyporheic zone and possible tracers of freeze-thaw conditions in the hyporheic zone. This is important in the context of the ongoing warming in McMurdo Dry Valleys and the supply of more meltwaters to the hyporheic zone of McMurdo Dry Valley streams.", "keywords": ["550", "Science", "Q", "silicon", "Antartica", "15. Life on land", "551", "01 natural sciences", "hyporheic zone", "silicon isotopes", "13. Climate action", "weathering", "Antarctica", "isotopes", "permafrost", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.3389/feart.2020.00229"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Earth%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3389/feart.2020.00229", "name": "item", "description": "10.3389/feart.2020.00229", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3389/feart.2020.00229"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-06-26T00:00:00Z"}}, {"id": "10.3389/feart.2020.00286", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:20:39Z", "type": "Journal Article", "created": "2020-07-14", "title": "Silicon Isotopic Composition of Dry and Wet-Based Glaciers in Antarctica", "description": "Glaciers and ice sheets export significant amounts of silicon (Si) to downstream ecosystems, impacting local and potentially global biogeochemical cycles. Recent studies have shown Si in Arctic glacial meltwaters to have an isotopically distinct signature when compared to non-glacial rivers. This is likely linked to subglacial weathering processes and mechanochemical reactions. However, there are currently no silicon isotope (\u03b430Si) data available from meltwater streams in Antarctica, limiting the current inferences on global glacial silicon isotopic composition and its drivers. To address this gap, we present dissolved silicon (DSi), \u03b430SiDSi and major ion data from meltwater streams draining a polythermal glacier in the region of the West Antarctic peninsula (King George Island) and a cold-based glacier in East Antarctica (Commonwealth Stream, McMurdo Dry Valleys). These data, alongside other global datasets, improve our understanding of how contrasting glacier thermal regime can impact upon Si cycling and therefore the \u03b430SiDSi composition. ud We find a similar \u03b430SiDSi composition between the two sites, with the streams on King George Island varying between -0.23 and +1.23\u2030 and the Commonwealth stream varying from -0.40 to +1.14\u2030. However, meltwater streams in King George Island have higher DSi concentrations, and the two glacial systems exhibit opposite DSi - \u03b430SiDSi trends. These contrasts likely result from differences in weathering processes, specifically the role of subglacial processes (King George Island) and, supraglacial processes followed by in-stream weathering in hyporheic zones (Commonwealth Stream). These findings are important when considering likely changes in nutrient fluxes from Antarctic glaciers under climatic warming scenarios and consequent shifts in glacial thermal regimes.", "keywords": ["silicon isotope geochemistry", "550", "Stream Weathering", "Science", "Q", "500", "Antartica", "subglacial weathering", "15. Life on land", "01 natural sciences", "silicon cycle", "13. Climate action", "stream weathering", "solicon isotope", "Silicon Cycle", "Antarctica", "Subglacial Weathering", "Silicon Isotope Geochemistry", "geochemistry", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://orca.cardiff.ac.uk/id/eprint/133147/2/feart-08-00286.pdf"}, {"href": "https://doi.org/10.3389/feart.2020.00286"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Earth%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3389/feart.2020.00286", "name": "item", "description": "10.3389/feart.2020.00286", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3389/feart.2020.00286"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-07-14T00:00:00Z"}}, {"id": "10.5281/zenodo.17742676", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:23:07Z", "type": "Dataset", "title": "Physicochemical parameters of Antarctic soils impacted by Pygoscelis penguins", "description": "unspecifiedThe production of this dataset was supported by ANID \u2013 FONDECYT 1241787 and ANID \u2013 Programa Iniciativa Cient\u00edfica Milenio ICN2021_002.", "keywords": ["Soil", "Water content", "pH", "Antarctica", "Phosphorus", "Nitrate", "Organic carbon", "Ammonium", "Penguin", "Pygoscelis"], "contacts": [{"organization": "Iannuzzi, Stefania, Gonz\u00e1lez, Mitza, Acu\u00f1a, Camilo, Gonz\u00e1lez, Javiera, Almendras, Katerin, Orlando, Julieta,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5281/zenodo.17742676"}, {"rel": "self", "type": "application/geo+json", "title": "10.5281/zenodo.17742676", "name": "item", "description": "10.5281/zenodo.17742676", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5281/zenodo.17742676"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2025-12-01T00:00:00Z"}}, {"id": "10449/83878", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:24:38Z", "type": "Journal Article", "created": "2023-10-27", "title": "Geology and elevation shape bacterial assembly in Antarctic endolithic communities", "description": "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.", "keywords": ["570", "Endolithic microbiome", "Shotgun metagenomics", "550", "Community assembly", "Settore BIO/07 - ECOLOGIA", "Altitude", "Granite", "Antarctica", "Sandstone"]}, "links": [{"href": "https://openpub.fmach.it/bitstream/10449/83878/1/2024%20STE%20Larsen.pdf"}, {"href": "https://doi.org/10449/83878"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10449/83878", "name": "item", "description": "10449/83878", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10449/83878"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-01-01T00:00:00Z"}}, {"id": "10449/83880", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:24:38Z", "type": "Journal Article", "created": "2024-01-19", "title": "Metagenomics untangles potential adaptations of Antarctic endolithic bacteria at the fringe of habitability", "description": "Survival and growth strategies of Antarctic endolithic microbes residing in Earth's driest and coldest desert remain virtually unknown. From 109 endolithic microbiomes, 4539 metagenome-assembled genomes were generated, 49.3\u00a0% of which were novel candidate bacterial species. We present evidence that trace gas oxidation and atmospheric chemosynthesis may be the prevalent strategies supporting metabolic activity and persistence of these ecosystems at the fringe of life and the limits of habitability.", "keywords": ["570", "Microbiota (mesh)", "Metagenomics (mesh)", "Habitability", "Antarctic Regions", "Astronomical Sciences", "5101 Astronomical Sciences (for-2020)", "Extremophiles", "Environmental Sciences (science-metrix)", "14. Life underwater", "Adaptation", "MAGs", "Antarctic Regions (mesh)", "Bacteria", "Microbiota", "51 Physical Sciences (for-2020)", "500", "Metagenome (mesh)", "15. Life on land", "13. Climate action", "Physical Sciences", "Bacteria (mesh)", "Antarctica", "Metagenome", "Metagenomics", "Environmental Sciences", "Settore BIO/19 - MICROBIOLOGIA GENERALE"]}, "links": [{"href": "https://openpub.fmach.it/bitstream/10449/83880/5/2024%20STE%20Albanese.pdf"}, {"href": "https://doi.org/10449/83880"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10449/83880", "name": "item", "description": "10449/83880", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10449/83880"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-03-01T00:00:00Z"}}, {"id": "10449/84316", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:24:38Z", "type": "Journal Article", "created": "2024-02-19", "title": "Novel endolithic bacteria of phylum Chloroflexota reveal a myriad of potential survival strategies in the Antarctic desert", "description": "ABSTRACTThe ice-free McMurdo Dry Valleys of Antarctica are dominated by nutrient-poor mineral soil and rocky outcrops. The principal habitat for microorganisms is within rocks (endolithic). In this environment, microorganisms are provided with protection against sub-zero temperatures, rapid thermal fluctuations, extreme dryness, and ultraviolet and solar radiation. Endolithic communities include lichen, algae, fungi, and a diverse array of bacteria. Chloroflexota is among the most abundant bacterial phyla present in these communities. Among the Chloroflexota are four novel classes of bacteria, here named Candidatus Spiritibacteria class. nov. (=UBA5177), Candidatus Martimicrobia class. nov. (=UBA4733), Candidatus Tarhunnaeia class. nov. (=UBA6077), and Candidatus Uliximicrobia class. nov. (=UBA2235). We retrieved 17 high-quality metagenome-assembled genomes (MAGs) that represent these four classes. Based on genome predictions, all these bacteria are inferred to be aerobic heterotrophs that encode enzymes for the catabolism of diverse sugars. These and other organic substrates are likely derived from lichen, algae, and fungi, as metabolites (including photosynthate), cell wall components, and extracellular matrix components. The majority of MAGs encode the capacity for trace gas oxidation using high-affinity uptake hydrogenases, which could provide energy and metabolic water required for survival and persistence. Furthermore, some MAGs encode the capacity to couple the energy generated from H 2 and CO oxidation to support carbon fixation (atmospheric chemosynthesis). All encode mechanisms for the detoxification and efflux of heavy metals. Certain MAGs encode features that indicate possible interactions with other organisms, such as Tc-type toxin complexes, hemolysins, and macroglobulins.
IMPORTANCEThe ice-free McMurdo Dry Valleys of Antarctica are the coldest and most hyperarid desert on Earth. It is, therefore, the closest analog to the surface of the planet Mars. Bacteria and other microorganisms survive by inhabiting airspaces within rocks (endolithic). We identify four novel classes of phylum Chloroflexota , and, based on interrogation of 17 metagenome-assembled genomes, we predict specific metabolic and physiological adaptations that facilitate the survival of these bacteria in this harsh environment\uffe2\uff80\uff94including oxidation of trace gases and the utilization of nutrients (including sugars) derived from lichen, algae, and fungi. We propose that such adaptations allow these endolithic bacteria to eke out an existence in this cold and extremely dry habitat.
", "keywords": ["570", "Bacteria", "Fungi", "Antarctic Regions", "Chloroflexi", "15. Life on land", "Survival strategies", "Cold Temperature", "Extremophiles", "13. Climate action", "Antarctica", "Endolithic communities", "Metagenomics", "14. Life underwater", "Sugars", "Settore BIO/19 - MICROBIOLOGIA GENERALE"]}, "links": [{"href": "https://doi.org/10449/84316"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Applied%20and%20Environmental%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10449/84316", "name": "item", "description": "10449/84316", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10449/84316"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-02-19T00:00:00Z"}}, {"id": "11104/0368761", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:24:46Z", "type": "Journal Article", "created": "2025-07-18", "title": "Two new psychrotolerant Massilia species inhibit plant pathogens Clavibacter and Curtobacterium", "description": "Three bacterial strains producing blue-violet pigmented colonies on R2A agar were isolated from a wet rock wall and lakes in a deglaciated northern part of James Ross Island, Antarctica. The isolated strains inhibited phytopathogenic Gram-positive bacteria, e.g. Clavibacter spp., Curtobacterium flacumfaciens, and Paenarthrobacter ilicis. Phylogenetic analysis based on the 16S rRNA gene indicated that the isolates belonged to the genus Massilia and the closest relatives were Massilia violaceinigra B2T, Massilia rubra CCM 8692T, Massilia frigida CCM 8695T, Massilia antarctica CCM 8941T, and Massilia aquatica CCM 8693T. A polyphasic taxonomic study based on lepA genes sequencing, automated ribotyping, MALDI-TOF MS, chemotaxonomy analyses, extensive biotyping, average nucleotide identity, and digital DNA-DNA hybridization calculations based on whole-genome sequences proved that the isolates represent a novel Massilia species for which the names Massilia pseudviolaceinigra sp. nov. and Massilia scottii sp. nov. are suggested, with the type strains P3689T (= CCM 9206T) and P5043T (= CCM 9029T), respectively. These two bioactive-substances-producing species may play an important role in shaping the composition of fresh-water Antarctic microbiomes due to the inhibition of various Gram-positive bacteria.
", "keywords": ["Plant-pathogenic", "Massilia", "Taxonomic description", "Antarctica", "Curtobacterium", "Clavibacter", "Article"]}, "links": [{"href": "https://doi.org/11104/0368761"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Scientific%20Reports", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "11104/0368761", "name": "item", "description": "11104/0368761", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/11104/0368761"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-06-13T00:00:00Z"}}, {"id": "11391/1548395", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:24:50Z", "type": "Journal Article", "created": "2023-02-22", "title": "Rock Traits Drive Complex Microbial Communities at the Edge of Life", "description": "Antarctic deserts are among the driest and coldest ecosystems of the planet; there, some microbes survive under these extreme conditions inside porous rocks, forming the so-called endolithic communities. Yet the contribution of distinct rock traits to support complex microbial assemblies remains poorly determined. Here, we combined an extensive Antarctic rock survey with rock microbiome sequencing and ecological networks and found that contrasting combinations of microclimatic and rock traits such as thermal inertia, porosity, iron concentration, and quartz cement can help explain the multiple complex microbial assemblies found in Antarctic rocks. Our work highlights the pivotal role of rocky substrate heterogeneity in sustaining contrasting groups of microorganisms, which is essential to understand life at the edge on Earth and for the search for life on other rocky planets such as Mars.", "keywords": ["570", "Earth", " Planet", "Habitability", "500", "Antarctica; Extremophiles; Biogeochemistry; Habitability; Astrobiology; Terrestrial analog;", "Planets", "Antarctic Regions", "Biogeochemistry", "15. Life on land", "Astrobiology", "Extremophiles", "Terrestrial analog", "13. Climate action", "Exobiology", "Antarctica", "14. Life underwater", "Settore BIO/19 - MICROBIOLOGIA GENERALE", "Ecosystem"]}, "links": [{"href": "https://doi.org/11391/1548395"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Astrobiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "11391/1548395", "name": "item", "description": "11391/1548395", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/11391/1548395"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2023-04-01T00:00:00Z"}}, {"id": "1983/5ade10d7-e52b-449b-a041-157faf95a175", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:25:08Z", "type": "Journal Article", "created": "2020-07-14", "title": "Silicon Isotopic Composition of Dry and Wet-Based Glaciers in Antarctica", "description": "Glaciers and ice sheets export significant amounts of silicon (Si) to downstream ecosystems, impacting local and potentially global biogeochemical cycles. Recent studies have shown Si in Arctic glacial meltwaters to have an isotopically distinct signature when compared to non-glacial rivers. This is likely linked to subglacial weathering processes and mechanochemical reactions. However, there are currently no silicon isotope (\u03b430Si) data available from meltwater streams in Antarctica, limiting the current inferences on global glacial silicon isotopic composition and its drivers. To address this gap, we present dissolved silicon (DSi), \u03b430SiDSi and major ion data from meltwater streams draining a polythermal glacier in the region of the West Antarctic peninsula (King George Island) and a cold-based glacier in East Antarctica (Commonwealth Stream, McMurdo Dry Valleys). These data, alongside other global datasets, improve our understanding of how contrasting glacier thermal regime can impact upon Si cycling and therefore the \u03b430SiDSi composition. ud We find a similar \u03b430SiDSi composition between the two sites, with the streams on King George Island varying between -0.23 and +1.23\u2030 and the Commonwealth stream varying from -0.40 to +1.14\u2030. However, meltwater streams in King George Island have higher DSi concentrations, and the two glacial systems exhibit opposite DSi - \u03b430SiDSi trends. These contrasts likely result from differences in weathering processes, specifically the role of subglacial processes (King George Island) and, supraglacial processes followed by in-stream weathering in hyporheic zones (Commonwealth Stream). These findings are important when considering likely changes in nutrient fluxes from Antarctic glaciers under climatic warming scenarios and consequent shifts in glacial thermal regimes.", "keywords": ["silicon isotope geochemistry", "550", "Stream Weathering", "Science", "Q", "500", "Antartica", "subglacial weathering", "15. Life on land", "01 natural sciences", "silicon cycle", "13. Climate action", "stream weathering", "solicon isotope", "Silicon Cycle", "Antarctica", "Subglacial Weathering", "Silicon Isotope Geochemistry", "geochemistry", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://orca.cardiff.ac.uk/id/eprint/133147/2/feart-08-00286.pdf"}, {"href": "https://doi.org/1983/5ade10d7-e52b-449b-a041-157faf95a175"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Earth%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "1983/5ade10d7-e52b-449b-a041-157faf95a175", "name": "item", "description": "1983/5ade10d7-e52b-449b-a041-157faf95a175", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/1983/5ade10d7-e52b-449b-a041-157faf95a175"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-07-14T00:00:00Z"}}, {"id": "1983/a9ecd79e-9249-4f29-b8fd-05f3f4442b8c", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:25:08Z", "type": "Journal Article", "created": "2020-06-26", "title": "Silicon Isotopes Reveal a Non-glacial Source of Silicon to Crescent Stream, McMurdo Dry Valleys, Antarctica", "description": "In high latitude environments, silicon is supplied to river waters by both glacial and non-glacial chemical weathering. The signal of these two end-members is often obscured by biological uptake and/or groundwater input in the river catchment. McMurdo Dry Valleys streams in Antarctica have no deep groundwater input, no connectivity between streams and no surface vegetation cover, and thus provide a simplified system for us to constrain the supply of dissolved silicon (DSi) to rivers from chemical weathering in a glacial environment. Here we report dissolved Si concentrations, germanium/silicon ratios (Ge/Si) and silicon isotope compositions (\u03b430SiDSi) in Crescent Stream, McMurdo Dry Valleys for samples collected between December and February in the 2014\u22122015, 2015\u22122016, and 2016\u22122017 austral seasons. The \u03b430SiDSi compositions and DSi concentrations are higher than values reported in wet-based glacial meltwaters, and form a narrow cluster within the range of values reported for permafrost dominated Arctic Rivers. High \u03b430SiDSi compositions, ranging from +0.90\u2030 to +1.39\u2030, are attributed to (i) the precipitation of amorphous silica during freezing of waters in isolated pockets of the hyporheic zone in the winter and the release of Si from unfrozen pockets during meltwater-hyporheic zone exchange in the austral summer, and (ii) additional Si isotope fractionation via long-term Si uptake in clay minerals and seasonal Si uptake into diatoms superimposed on this winter-derived isotope signal. There is no relationship between \u03b430SiDSi compositions and DSi concentrations with seasonal and daily discharge, showing that stream waters contain DSi that is in equilibrium with the formation of secondary Si minerals in the hyporheic zone. We show that \u03b430SiDSi compositions can be used as tracers of silicate weathering in the hyporheic zone and possible tracers of freeze-thaw conditions in the hyporheic zone. This is important in the context of the ongoing warming in McMurdo Dry Valleys and the supply of more meltwaters to the hyporheic zone of McMurdo Dry Valley streams.", "keywords": ["550", "Science", "Q", "silicon", "Antartica", "15. Life on land", "551", "01 natural sciences", "hyporheic zone", "silicon isotopes", "13. Climate action", "weathering", "Antarctica", "isotopes", "permafrost", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/1983/a9ecd79e-9249-4f29-b8fd-05f3f4442b8c"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Earth%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "1983/a9ecd79e-9249-4f29-b8fd-05f3f4442b8c", "name": "item", "description": "1983/a9ecd79e-9249-4f29-b8fd-05f3f4442b8c", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/1983/a9ecd79e-9249-4f29-b8fd-05f3f4442b8c"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-06-26T00:00:00Z"}}, {"id": "2440/132742", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:25:32Z", "type": "Journal Article", "created": "2018-01-10", "title": "Ecological drivers of soil microbial diversity and soil biological networks in the Southern Hemisphere", "description": "AbstractThe ecological drivers of soil biodiversity in the Southern Hemisphere remain underexplored. Here, in a continental survey comprising 647 sites, across 58 degrees of latitude between tropical Australia and Antarctica, we evaluated the major ecological patterns in soil biodiversity and relative abundance of ecological clusters within a co\uffe2\uff80\uff90occurrence network of soil bacteria, archaea and eukaryotes. Six major ecological clusters (modules) of co\uffe2\uff80\uff90occurring soil taxa were identified. These clusters exhibited strong shifts in their relative abundances with increasing distance from the equator. Temperature was the major environmental driver of the relative abundance of ecological clusters when Australia and Antarctica are analyzed together. Temperature, aridity, soil properties and vegetation types were the major drivers of the relative abundance of different ecological clusters within Australia. Our data supports significant reductions in the diversity of bacteria, archaea and eukaryotes in Antarctica vs. Australia linked to strong reductions in temperature. However, we only detected small latitudinal variations in soil biodiversity within Australia. Different environmental drivers regulate the diversity of soil archaea (temperature and soil carbon), bacteria (aridity, vegetation attributes and pH) and eukaryotes (vegetation type and soil carbon) across Australia. Together, our findings provide new insights into the mechanisms driving soil biodiversity in the Southern Hemisphere.