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Savaglia V, Lambrechts S, Tytgat B, Vanhellemont Q, Elster J, Willems A, Wilmotte A, Verleyen E, Vyverman W. Geology defines microbiome structure and composition in nunataks and valleys of the Sør Rondane Mountains, East Antarctica. Front Microbiol 2024; 15:1316633. [PMID: 38380088 PMCID: PMC10877063 DOI: 10.3389/fmicb.2024.1316633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 01/09/2024] [Indexed: 02/22/2024] Open
Abstract
Understanding the relation between terrestrial microorganisms and edaphic factors in the Antarctic can provide insights into their potential response to environmental changes. Here we examined the composition of bacterial and micro-eukaryotic communities using amplicon sequencing of rRNA genes in 105 soil samples from the Sør Rondane Mountains (East Antarctica), differing in bedrock or substrate type and associated physicochemical conditions. Although the two most widespread taxa (Acidobacteriota and Chlorophyta) were relatively abundant in each sample, multivariate analysis and co-occurrence networks revealed pronounced differences in community structure depending on substrate type. In moraine substrates, Actinomycetota and Cercozoa were the most abundant bacterial and eukaryotic phyla, whereas on gneiss, granite and marble substrates, Cyanobacteriota and Metazoa were the dominant bacterial and eukaryotic taxa. However, at lower taxonomic level, a distinct differentiation was observed within the Cyanobacteriota phylum depending on substrate type, with granite being dominated by the Nostocaceae family and marble by the Chroococcidiopsaceae family. Surprisingly, metazoans were relatively abundant according to the 18S rRNA dataset, even in samples from the most arid sites, such as moraines in Austkampane and Widerøefjellet ("Dry Valley"). Overall, our study shows that different substrate types support distinct microbial communities, and that mineral soil diversity is a major determinant of terrestrial microbial diversity in inland Antarctic nunataks and valleys.
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Affiliation(s)
- Valentina Savaglia
- InBioS Research Unit, Department of Life Sciences, University of Liège, Liège, Belgium
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Sam Lambrechts
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Bjorn Tytgat
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | | | - Josef Elster
- Faculty of Science, Centre for Polar Ecology, University of South Bohemia České Budějovice and Institute of Botany, Třeboň, Czechia
| | - Anne Willems
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Annick Wilmotte
- InBioS Research Unit, Department of Life Sciences, University of Liège, Liège, Belgium
| | - Elie Verleyen
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Wim Vyverman
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
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Garvin ZK, Abades SR, Trefault N, Alfaro FD, Sipes K, Lloyd KG, Onstott TC. Prevalence of trace gas-oxidizing soil bacteria increases with radial distance from Polloquere hot spring within a high-elevation Andean cold desert. THE ISME JOURNAL 2024; 18:wrae062. [PMID: 38625060 PMCID: PMC11094475 DOI: 10.1093/ismejo/wrae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/29/2024] [Accepted: 04/10/2024] [Indexed: 04/17/2024]
Abstract
High-elevation arid regions harbor microbial communities reliant on metabolic niches and flexibility to survive under biologically stressful conditions, including nutrient limitation that necessitates the utilization of atmospheric trace gases as electron donors. Geothermal springs present "oases" of microbial activity, diversity, and abundance by delivering water and substrates, including reduced gases. However, it is unknown whether these springs exhibit a gradient of effects, increasing their impact on trace gas-oxidizers in the surrounding soils. We assessed whether proximity to Polloquere, a high-altitude geothermal spring in an Andean salt flat, alters the diversity and metabolic structure of nearby soil bacterial populations compared to the surrounding cold desert. Recovered DNA and metagenomic analyses indicate that the spring represents an oasis for microbes in this challenging environment, supporting greater biomass with more diverse metabolic functions in proximal soils that declines sharply with radial distance from the spring. Despite the sharp decrease in biomass, potential rates of atmospheric hydrogen (H2) and carbon monoxide (CO) uptake increase away from the spring. Kinetic estimates suggest this activity is due to high-affinity trace gas consumption, likely as a survival strategy for energy/carbon acquisition. These results demonstrate that Polloquere regulates a gradient of diverse microbial communities and metabolisms, culminating in increased activity of trace gas-oxidizers as the influence of the spring yields to that of the regional salt flat environment. This suggests the spring holds local importance within the context of the broader salt flat and potentially represents a model ecosystem for other geothermal systems in high-altitude desert environments.
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Affiliation(s)
- Zachary K Garvin
- Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
| | - Sebastián R Abades
- GEMA Center for Genomics, Ecology and Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, 8580745, Santiago, Chile
| | - Nicole Trefault
- GEMA Center for Genomics, Ecology and Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, 8580745, Santiago, Chile
| | - Fernando D Alfaro
- GEMA Center for Genomics, Ecology and Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, 8580745, Santiago, Chile
| | - Katie Sipes
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
- Department of Environmental Science, Aarhus University, 4000, Roskilde, Denmark
| | - Karen G Lloyd
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tullis C Onstott
- Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
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Wood C, Bruinink A, Trembath-Reichert E, Wilhelm MB, Vidal C, Balaban E, McKay CP, Swan R, Swan B, Goordial J. Active microbiota persist in dry permafrost and active layer from Elephant Head, Antarctica. ISME COMMUNICATIONS 2024; 4:ycad002. [PMID: 38304082 PMCID: PMC10833075 DOI: 10.1093/ismeco/ycad002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 10/03/2023] [Accepted: 11/07/2023] [Indexed: 02/03/2024]
Abstract
Dry permafrost is a challenging environment for microbial life due to cold, dry, and often oligotrophic conditions. In 2016, Elephant Head, Antarctica, was confirmed as the second site on Earth to contain dry permafrost. It is geographically distinct from the McMurdo Dry Valleys where dry permafrost has been studied previously. Here, we present the first study of the microbial activity, diversity, and functional potential of Elephant Head dry permafrost. Microbial activity was measured using radiorespiration assays with radiolabeled acetate as a carbon source at 5, 0, and -5°C. Low, but detectable, rates of microbial activity were measured in some samples at 0 and -5°C. This is distinct from previous studies of McMurdo Dry Valley dry permafrost which concluded that dry permafrost represents a cold-arid limit to life on the planet. The isolation of cold-adapted organisms from these soils, including one capable of subzero growth, further supports that the Elephant Head dry active layer and dry permafrost harbor viable microbial life, which may be active in situ. Metagenomic, 16S rRNA gene, and internal transcribed spacer and amplicon sequencing identified similar microbial communities to other Antarctic and cold environments. The Elephant Head microbial community appears to be adapted for survival in cold, dry, and oligotrophic conditions based on the presence of cold adaptation and stress response genes in the metagenomes. Together, our results show that dry permafrost environments do not exclude active microbial life at subzero temperatures, suggesting that the cold, dry soils of Mars may also not be as inhospitable as previously thought.
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Affiliation(s)
- Claudia Wood
- School of Environmental Sciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
| | - Alyssa Bruinink
- School of Environmental Sciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
| | - Elizabeth Trembath-Reichert
- School of Earth and Space Exploration, Arizona State University, 781 Terrace Mall, Tempe, AZ 85287, United States
| | - Mary Beth Wilhelm
- Space Science & Astrobiology Division, NASA Ames Research Center, Moffett Field, CA 94035, United States
| | - Chanel Vidal
- School of Earth and Space Exploration, Arizona State University, 781 Terrace Mall, Tempe, AZ 85287, United States
| | - Edward Balaban
- Space Science & Astrobiology Division, NASA Ames Research Center, Moffett Field, CA 94035, United States
| | - Christopher P McKay
- Space Science & Astrobiology Division, NASA Ames Research Center, Moffett Field, CA 94035, United States
| | - Robert Swan
- 2041 Foundation, 130 Wescott Ct, Auburn, CA 95603, United States
| | - Barney Swan
- 2041 Foundation, 130 Wescott Ct, Auburn, CA 95603, United States
| | - Jackie Goordial
- School of Environmental Sciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
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Mashamaite L, Lebre PH, Varliero G, Maphosa S, Ortiz M, Hogg ID, Cowan DA. Microbial diversity in Antarctic Dry Valley soils across an altitudinal gradient. Front Microbiol 2023; 14:1203216. [PMID: 37555066 PMCID: PMC10406297 DOI: 10.3389/fmicb.2023.1203216] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 06/23/2023] [Indexed: 08/10/2023] Open
Abstract
INTRODUCTION The Antarctic McMurdo Dry Valleys are geologically diverse, encompassing a wide variety of soil habitats. These environments are largely dominated by microorganisms, which drive the ecosystem services of the region. While altitude is a well-established driver of eukaryotic biodiversity in these Antarctic ice-free areas (and many non-Antarctic environments), little is known of the relationship between altitude and microbial community structure and functionality in continental Antarctica. METHODS We analysed prokaryotic and lower eukaryotic diversity from soil samples across a 684 m altitudinal transect in the lower Taylor Valley, Antarctica and performed a phylogenic characterization of soil microbial communities using short-read sequencing of the 16S rRNA and ITS marker gene amplicons. RESULTS AND DISCUSSION Phylogenetic analysis showed clear altitudinal trends in soil microbial composition and structure. Cyanobacteria were more prevalent in higher altitude samples, while the highly stress resistant Chloroflexota and Deinococcota were more prevalent in lower altitude samples. We also detected a shift from Basidiomycota to Chytridiomycota with increasing altitude. Several genera associated with trace gas chemotrophy, including Rubrobacter and Ornithinicoccus, were widely distributed across the entire transect, suggesting that trace-gas chemotrophy may be an important trophic strategy for microbial survival in oligotrophic environments. The ratio of trace-gas chemotrophs to photoautotrophs was significantly higher in lower altitude samples. Co-occurrence network analysis of prokaryotic communities showed some significant differences in connectivity within the communities from different altitudinal zones, with cyanobacterial and trace-gas chemotrophy-associated taxa being identified as potential keystone taxa for soil communities at higher altitudes. By contrast, the prokaryotic network at low altitudes was dominated by heterotrophic keystone taxa, thus suggesting a clear trophic distinction between soil prokaryotic communities at different altitudes. Based on these results, we conclude that altitude is an important driver of microbial ecology in Antarctic ice-free soil habitats.
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Affiliation(s)
- Lefentse Mashamaite
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa
| | - Pedro H. Lebre
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa
| | - Gilda Varliero
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Silindile Maphosa
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa
| | - Max Ortiz
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa
- Clemson University Genomics & Bioinformatics Facility, Clemson University, Clemson, SC, United States
| | - Ian D. Hogg
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa
- School of Science, University of Waikato, Hamilton, New Zealand
- Canadian High Arctic Research Station, Polar Knowledge Canada, Cambridge Bay, NU, Canada
| | - Don A. Cowan
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa
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Cowan DA, Cary SC, DiRuggiero J, Eckardt F, Ferrari B, Hopkins DW, Lebre PH, Maggs-Kölling G, Pointing SB, Ramond JB, Tribbia D, Warren-Rhodes K. 'Follow the Water': Microbial Water Acquisition in Desert Soils. Microorganisms 2023; 11:1670. [PMID: 37512843 PMCID: PMC10386458 DOI: 10.3390/microorganisms11071670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/12/2023] [Accepted: 06/16/2023] [Indexed: 07/30/2023] Open
Abstract
Water availability is the dominant driver of microbial community structure and function in desert soils. However, these habitats typically only receive very infrequent large-scale water inputs (e.g., from precipitation and/or run-off). In light of recent studies, the paradigm that desert soil microorganisms are largely dormant under xeric conditions is questionable. Gene expression profiling of microbial communities in desert soils suggests that many microbial taxa retain some metabolic functionality, even under severely xeric conditions. It, therefore, follows that other, less obvious sources of water may sustain the microbial cellular and community functionality in desert soil niches. Such sources include a range of precipitation and condensation processes, including rainfall, snow, dew, fog, and nocturnal distillation, all of which may vary quantitatively depending on the location and geomorphological characteristics of the desert ecosystem. Other more obscure sources of bioavailable water may include groundwater-derived water vapour, hydrated minerals, and metabolic hydro-genesis. Here, we explore the possible sources of bioavailable water in the context of microbial survival and function in xeric desert soils. With global climate change projected to have profound effects on both hot and cold deserts, we also explore the potential impacts of climate-induced changes in water availability on soil microbiomes in these extreme environments.
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Affiliation(s)
- Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
| | - S Craig Cary
- School of Biological Sciences, University of Waikato, Hamilton 3216, New Zealand
| | - Jocelyne DiRuggiero
- Departments of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
- Departments of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Frank Eckardt
- Department of Environmental and Geographical Science, University of Cape Town, Cape Town 7701, South Africa
| | - Belinda Ferrari
- School of Biotechnology and Biological Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - David W Hopkins
- Scotland's Rural College, West Mains Road, Edinburgh EH9 3JG, UK
| | - Pedro H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
| | | | - Stephen B Pointing
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Jean-Baptiste Ramond
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
- Departamento Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile
| | - Dana Tribbia
- School of Biotechnology and Biological Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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Abstract
The island of Hunga Tonga Hunga Ha'apai (HTHH) in the Kingdom of Tonga was formed by Surtseyan eruptions and persisted for 7 years before being obliterated by a massive volcanic eruption on 15 January 2022. Before it was destroyed, HTHH was an unparalleled natural laboratory to study primary succession on a newly formed landmass. We characterized the microbial communities found on the surface sediments of HTHH using a combination of quantitative PCR, marker gene sequencing, and shotgun metagenomic analyses. Contrary to expectations, photosynthetic cyanobacteria were not detected in these sediments, even though they are typically dominant in the earliest stages of primary succession in other terrestrial environments. Instead, our results suggest that the early sediment communities were composed of a diverse array of bacterial taxa, including trace gas oxidizers, anoxygenic photosynthesizers, and chemolithotrophs capable of metabolizing inorganic sulfur, with these bacteria likely sourced from nearby active geothermal environments. While the destruction of HTHH makes it impossible to revisit the site to conduct in situ metabolic measurements or observe how the microbial communities might have continued to change over time, our results do suggest that the early microbial colonizers have unique origins and metabolic capabilities. IMPORTANCE The volcanic island of Hunga Tonga Hunga Ha'apai in the Kingdom of Tonga represents a very rare example of new island formation and thus a unique opportunity to study how organisms colonize a new landmass. We found that the island was colonized by diverse microbial communities shortly after its formation in 2015, with these microbes likely originating from nearby geothermal environments. Primary succession in this system was distinct from that typically observed in other terrestrial environments, with the early microbial colonizers relying on unique metabolic strategies to survive on the surface of this newly formed island, including the capacity to generate energy via sulfur and trace gas metabolism.
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Lee JR, Waterman MJ, Shaw JD, Bergstrom DM, Lynch HJ, Wall DH, Robinson SA. Islands in the ice: Potential impacts of habitat transformation on Antarctic biodiversity. GLOBAL CHANGE BIOLOGY 2022; 28:5865-5880. [PMID: 35795907 PMCID: PMC9542894 DOI: 10.1111/gcb.16331] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 06/15/2022] [Indexed: 05/04/2023]
Abstract
Antarctic biodiversity faces an unknown future with a changing climate. Most terrestrial biota is restricted to limited patches of ice-free land in a sea of ice, where they are adapted to the continent's extreme cold and wind and exploit microhabitats of suitable conditions. As temperatures rise, ice-free areas are predicted to expand, more rapidly in some areas than others. There is high uncertainty as to how species' distributions, physiology, abundance, and survivorship will be affected as their habitats transform. Here we use current knowledge to propose hypotheses that ice-free area expansion (i) will increase habitat availability, though the quality of habitat will vary; (ii) will increase structural connectivity, although not necessarily increase opportunities for species establishment; (iii) combined with milder climates will increase likelihood of non-native species establishment, but may also lengthen activity windows for all species; and (iv) will benefit some species and not others, possibly resulting in increased homogeneity of biodiversity. We anticipate considerable spatial, temporal, and taxonomic variation in species responses, and a heightened need for interdisciplinary research to understand the factors associated with ecosystem resilience under future scenarios. Such research will help identify at-risk species or vulnerable localities and is crucial for informing environmental management and policymaking into the future.
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Affiliation(s)
- Jasmine R. Lee
- British Antarctic SurveyNERCCambridgeUK
- Securing Antarctica's Environmental Future, School of Biology and Environmental ScienceQueensland University of TechnologyBrisbaneQLDAustralia
| | - Melinda J. Waterman
- Securing Antarctica's Environmental Future, School of Earth, Atmospheric and Life SciencesUniversity of WollongongWollongongNew South WalesAustralia
| | - Justine D. Shaw
- Securing Antarctica's Environmental Future, School of Biology and Environmental ScienceQueensland University of TechnologyBrisbaneQLDAustralia
| | - Dana M. Bergstrom
- Australian Antarctic Division, Department of AgricultureWater and the EnvironmentKingstonTASAustralia
- Global Challenges ProgramUniversity of WollongongWollongongNew South WalesAustralia
| | - Heather J. Lynch
- Department of Ecology and EvolutionStony Brook UniversityStony BrookNew YorkUSA
| | - Diana H. Wall
- Department of Biology and School of Global Environmental SustainabilityColorado State UniversityFort CollinsColoradoUSA
| | - Sharon A. Robinson
- Securing Antarctica's Environmental Future, School of Earth, Atmospheric and Life SciencesUniversity of WollongongWollongongNew South WalesAustralia
- Global Challenges ProgramUniversity of WollongongWollongongNew South WalesAustralia
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