1
|
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.
Collapse
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
| | | |
Collapse
|
2
|
Jackson AC, Jorna J, Chaston JM, Adams BJ. Glacial Legacies: Microbial Communities of Antarctic Refugia. BIOLOGY 2022; 11:biology11101440. [PMID: 36290344 PMCID: PMC9598129 DOI: 10.3390/biology11101440] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/26/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
In the cold deserts of the McMurdo Dry Valleys (MDV) the suitability of soil for microbial life is determined by both contemporary processes and legacy effects. Climatic changes and accompanying glacial activity have caused local extinctions and lasting geochemical changes to parts of these soil ecosystems over several million years, while areas of refugia may have escaped these disturbances and existed under relatively stable conditions. This study describes the impact of historical glacial and lacustrine disturbance events on microbial communities across the MDV to investigate how this divergent disturbance history influenced the structuring of microbial communities across this otherwise very stable ecosystem. Soil bacterial communities from 17 sites representing either putative refugia or sites disturbed during the Last Glacial Maximum (LGM) (22-17 kya) were characterized using 16 S metabarcoding. Regardless of geographic distance, several putative refugia sites at elevations above 600 m displayed highly similar microbial communities. At a regional scale, community composition was found to be influenced by elevation and geographic proximity more so than soil geochemical properties. These results suggest that despite the extreme conditions, diverse microbial communities exist in these putative refugia that have presumably remained undisturbed at least through the LGM. We suggest that similarities in microbial communities can be interpreted as evidence for historical climate legacies on an ecosystem-wide scale.
Collapse
Affiliation(s)
- Abigail C. Jackson
- Department of Biology, Brigham Young University, Provo, UT 84602, USA
- Correspondence: (A.C.J.); (J.J.)
| | - Jesse Jorna
- Department of Biology, Brigham Young University, Provo, UT 84602, USA
- Correspondence: (A.C.J.); (J.J.)
| | - John M. Chaston
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT 84602, USA
| | - Byron J. Adams
- Department of Biology, Brigham Young University, Provo, UT 84602, USA
- Monte L. Bean Museum, Brigham Young University, Provo, UT 84602, USA
| |
Collapse
|
3
|
Severgnini M, Canini F, Consolandi C, Camboni T, Paolo D'Acqui L, Mascalchi C, Ventura S, Zucconi L. Highly differentiated soil bacterial communities in Victoria Land macro-areas (Antarctica). FEMS Microbiol Ecol 2021; 97:6307020. [PMID: 34151349 DOI: 10.1093/femsec/fiab087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/17/2021] [Indexed: 11/13/2022] Open
Abstract
Ice-free areas of Victoria Land, in Antarctica, are characterized by different terrestrial ecosystems, that are dominated by microorganisms supporting highly adapted communities. Despite the unique conditions of these ecosystems, reports on their bacterial diversity are still fragmentary. From this perspective, 60 samples from 14 localities were analyzed. These localities were distributed in coastal sites with differently developed biological soil crusts, inner sites in the McMurdo Dry Valleys with soils lacking of plant coverage, and a site called Icarus Camp, with a crust developed on a thin locally weathered substrate of the underlying parent granitic-rock. Bacterial diversity was studied through 16S rRNA metabarcoding sequencing. Communities diversity, composition and the abundance and composition of different taxonomic groups were correlated to soil physicochemical characteristics. Firmicutes, Bacteroidetes, Cyanobacteria and Proteobacteria dominated these communities. Most phyla were mainly driven by soil granulometry, an often disregarded parameter and other abiotic parameters. Bacterial composition differed greatly among the three macrohabitats, each having a distinct bacterial profile. Communities within the two main habitats (coastal and inner ones) were well differentiated from each other as well, therefore depending on site-specific physicochemical characteristics. A core community of the whole samples was observed, mainly represented by Firmicutes and Bacteroidetes.
Collapse
Affiliation(s)
- Marco Severgnini
- Institute of Biomedical Technologies, National Research Council (ITB-CNR), via f.lli Cervi, 93, 20054, Segrate, Italy
| | - Fabiana Canini
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università s.n.c., 01100, Viterbo, Italy
| | - Clarissa Consolandi
- Institute of Biomedical Technologies, National Research Council (ITB-CNR), via f.lli Cervi, 93, 20054, Segrate, Italy
| | - Tania Camboni
- Institute of Biomedical Technologies, National Research Council (ITB-CNR), via f.lli Cervi, 93, 20054, Segrate, Italy
| | - Luigi Paolo D'Acqui
- Terrestria Ecosystems Research Institute, National Research Council (IRET-CNR), Via Madonna del Piano 10, 50019, Sesto Fiorentino, Italy
| | - Cristina Mascalchi
- Terrestria Ecosystems Research Institute, National Research Council (IRET-CNR), Via Madonna del Piano 10, 50019, Sesto Fiorentino, Italy
| | - Stefano Ventura
- Terrestria Ecosystems Research Institute, National Research Council (IRET-CNR), Via Madonna del Piano 10, 50019, Sesto Fiorentino, Italy.,The Italian Embassy in Israel, Trade Tower, 25 Hamered Street, 68125, Tel Aviv, Israel
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell'Università s.n.c., 01100, Viterbo, Italy
| |
Collapse
|
4
|
Coyne KJ, Parker AE, Lee CK, Sohm JA, Kalmbach A, Gunderson T, León-Zayas R, Capone DG, Carpenter EJ, Cary SC. The distribution and relative ecological roles of autotrophic and heterotrophic diazotrophs in the McMurdo Dry Valleys, Antarctica. FEMS Microbiol Ecol 2020; 96:5714082. [PMID: 31967635 PMCID: PMC7043275 DOI: 10.1093/femsec/fiaa010] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 01/21/2020] [Indexed: 12/13/2022] Open
Abstract
The McMurdo Dry Valleys (MDV) in Antarctica harbor a diverse assemblage of mat-forming diazotrophic cyanobacteria that play a key role in nitrogen cycling. Prior research showed that heterotrophic diazotrophs also make a substantial contribution to nitrogen fixation in MDV. The goals of this study were to survey autotrophic and heterotrophic diazotrophs across the MDV to investigate factors that regulate the distribution and relative ecological roles of each group. Results indicated that diazotrophs were present only in samples with mats, suggesting a metabolic coupling between autotrophic and heterotrophic diazotrophs. Analysis of 16S rRNA and nifH gene sequences also showed that diazotrophs were significantly correlated to the broader bacterial community, while co-occurrence network analysis revealed potential interspecific interactions. Consistent with previous studies, heterotrophic diazotrophs in MDV were diverse, but largely limited to lakes and their outlet streams, or other environments protected from desiccation. Despite the limited distribution, heterotrophic diazotrophs may make a substantial contribution to the nitrogen budget of MDV due to larger surface area and longer residence times of lakes. This work contributes to our understanding of key drivers of bacterial community structure in polar deserts and informs future efforts to investigate the contribution of nitrogen fixation to MDV ecosystems.
Collapse
Affiliation(s)
- Kathryn J Coyne
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE 19958, USA
| | - Alexander E Parker
- Estuary and Ocean Science Center, San Francisco State University, Tiburon, CA 94920, USA
| | - Charles K Lee
- International Centre for Terrestrial Antarctic Research, School of Science, University of Waikato, Hamilton 3240, New Zealand
| | - Jill A Sohm
- Wrigley Institute for Environmental Studies and Department of Biological Sciences, University of Southern California, Los Angeles, CA 9008-037, USA
| | - Andrew Kalmbach
- Estuary and Ocean Science Center, San Francisco State University, Tiburon, CA 94920, USA
| | - Troy Gunderson
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 9008-037, USA
| | - Rosa León-Zayas
- Willamette University, Biology Department, Salem, OR 97301, USA
| | - Douglas G Capone
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 9008-037, USA
| | - Edward J Carpenter
- Estuary and Ocean Science Center, San Francisco State University, Tiburon, CA 94920, USA
| | - S Craig Cary
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE 19958, USA.,International Centre for Terrestrial Antarctic Research, School of Science, University of Waikato, Hamilton 3240, New Zealand
| |
Collapse
|
5
|
Sohm JA, Niederberger TD, Parker AE, Tirindelli J, Gunderson T, Cary SC, Capone DG, Carpenter EJ. Microbial Mats of the McMurdo Dry Valleys, Antarctica: Oases of Biological Activity in a Very Cold Desert. Front Microbiol 2020; 11:537960. [PMID: 33193125 PMCID: PMC7654227 DOI: 10.3389/fmicb.2020.537960] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 09/28/2020] [Indexed: 11/29/2022] Open
Abstract
Cyanobacterial mats in the Antarctic Dry Valleys are photosynthetic microbial ecosystems living at the extreme of conditions on Earth with respect to temperature, light, water and nutrient availability. They are metabolically active for about 8 weeks during the austral summer when temperatures briefly rise above freezing and glacial and lake melt waters are available. There is much to learn about the biogeochemical impact of mats in these environments and the microbial communities associated with them. Our data demonstrate that these mats attain surprisingly high rates of carbon (CO2) and dinitrogen (N2) fixation when liquid water is available, in some cases comparable to rates in warmer temperate or tropical environments. C and N2 fixation in Dry Valley mats in turn substantially elevate dissolved organic C and inorganic N pools and thereby promote enhanced microbial secondary production. Moreover, the microbial community fingerprint of these mats is unique compared with the more ubiquitous dry soils that do not contain mats. Components of the heterotrophic microbiota may also contribute substantially to N inputs through N2 fixation.
Collapse
Affiliation(s)
- Jill A Sohm
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, CA, United States.,Environmental Studies Program, University of Southern California, Los Angeles, CA, United States
| | - Thomas D Niederberger
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, United States
| | - Alexander E Parker
- Estuary and Ocean Science Center, San Francisco State University, Tiburon, CA, United States.,Department of Sciences and Mathematics, California State University Maritime Academy, Vallejo, CA, United States
| | - Joëlle Tirindelli
- Estuary and Ocean Science Center, San Francisco State University, Tiburon, CA, United States
| | - Troy Gunderson
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Stephen Craig Cary
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, United States.,International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton, New Zealand
| | - Douglas G Capone
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Edward J Carpenter
- Estuary and Ocean Science Center, San Francisco State University, Tiburon, CA, United States
| |
Collapse
|
6
|
Mergelov N, Dolgikh A, Shorkunov I, Zazovskaya E, Soina V, Yakushev A, Fedorov-Davydov D, Pryakhin S, Dobryansky A. Hypolithic communities shape soils and organic matter reservoirs in the ice-free landscapes of East Antarctica. Sci Rep 2020; 10:10277. [PMID: 32581283 PMCID: PMC7314805 DOI: 10.1038/s41598-020-67248-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/04/2020] [Indexed: 12/29/2022] Open
Abstract
The soils of East Antarctica have no rhizosphere with the bulk of organo-mineral interactions confined to the thin microbial and cryptogamic crusts that occur in open or cryptic niches and are collectively known as biological soil crust (BSC). Here we demonstrate that cryptic hypolithic varieties of BSC in the Larsemann Hills of East Antarctica contribute to the buildup of soil organic matter and produce several types of continuous organogenous horizons within the topsoil with documented clusters of at least 100 m2. Such hypolithic horizons accumulate 0.06-4.69% of organic carbon (TOC) with isotopic signatures (δ13Corg) within the range of -30.2 - -24.0‰, and contain from 0 to 0.38% total nitrogen (TN). The properties of hypolithic organic matter alternate between cyanobacteria- and moss-dominated horizons, which are linked to the meso- and microtopography patterns and moisture gradients. The major part of TOC that is stored in hypolithic horizons has modern or centenary 14C age, while the minor part is stabilized on a millennial timescale through shallow burial and association with minerals. Our findings suggest that hypolithic communities create a "gateway" for organic carbon to enter depauperate soils of the Larsemann Hills and contribute to the carbon reservoir of the topsoil at a landscape level.
Collapse
Affiliation(s)
- Nikita Mergelov
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia.
| | - Andrey Dolgikh
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia
| | - Ilya Shorkunov
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia
| | - Elya Zazovskaya
- Institute of Geography, Russian Academy of Sciences, 119017, Moscow, Russia
| | - Vera Soina
- Faculty of Soil Science, Moscow State University, 119991, Moscow, Russia
| | - Andrey Yakushev
- Faculty of Soil Science, Moscow State University, 119991, Moscow, Russia
| | - Dmitry Fedorov-Davydov
- Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, 142290, Pushchino, Russia
| | - Sergey Pryakhin
- Arctic and Antarctic Research Institute, 199397, Saint Petersburg, Russia
| | | |
Collapse
|
7
|
Trout-Haney JV, Heindel RC, Virginia RA. Picocyanobacterial cells in near-surface air above terrestrial and freshwater substrates in Greenland and Antarctica. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:296-305. [PMID: 32134187 DOI: 10.1111/1758-2229.12832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 02/26/2020] [Accepted: 03/01/2020] [Indexed: 06/10/2023]
Abstract
Bioaerosols are an important component of the total atmospheric aerosol load, with implications for human health, climate feedbacks and the distribution and dispersal of microbial taxa. Bioaerosols are sourced from marine, freshwater and terrestrial surfaces, with different mechanisms potentially responsible for releasing biological particles from these substrates. Little is known about the production of freshwater and terrestrial bioaerosols in polar regions. We used portable collection devices to test for the presence of picocyanobacterial aerosols above freshwater and soil substrates in the southwestern Greenland tundra and the McMurdo Dry Valleys of Antarctica. We show that picocyanobacterial cells are present in the near-surface air at concentrations ranging from 2,431 to 28,355 cells m-3 of air, with no significant differences among substrates or between polar regions. Our concentrations are lower than those measured using the same methods in temperate ecosystems. We suggest that aerosolization is an important process linking terrestrial and aquatic ecosystems in these polar environments, and that future work is needed to explore aerosolization mechanisms and taxon-specific aerosolization rates. Our study is a first step toward understanding the production of bioaerosols in extreme environments dominated by microbial life.
Collapse
Affiliation(s)
- Jessica V Trout-Haney
- Department of Biological Sciences, Life Sciences Center, Dartmouth College, Hanover, NH, 03755
| | - Ruth C Heindel
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO
| | - Ross A Virginia
- Environmental Studies Program and Institute of Arctic Studies, Dartmouth College, Hanover, NH, 03755
| |
Collapse
|
8
|
Barnard S, Van Goethem MW, de Scally SZ, Cowan DA, van Rensburg PJ, Claassens S, Makhalanyane TP. Increased temperatures alter viable microbial biomass, ammonia oxidizing bacteria and extracellular enzymatic activities in Antarctic soils. FEMS Microbiol Ecol 2020; 96:5818763. [DOI: 10.1093/femsec/fiaa065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 04/03/2020] [Indexed: 12/13/2022] Open
Abstract
ABSTRACT
The effects of temperature on microorganisms in high latitude regions, and their possible feedbacks in response to change, are unclear. Here, we assess microbial functionality and composition in response to a substantial temperature change. Total soil biomass, amoA gene sequencing, extracellular activity assays and soil physicochemistry were measured to assess a warming scenario. Soil warming to 15°C for 30 days triggered a significant decrease in microbial biomass compared to baseline soils (0°C; P < 0.05) after incubations had induced an initial increase. These changes coincided with increases in extracellular enzymatic activity for peptide hydrolysis and phenolic oxidation at higher temperatures, but not for the degradation of carbon substrates. Shifts in ammonia-oxidising bacteria (AOB) community composition related most significantly to changes in soil carbon content (P < 0.05), which gradually increased in microcosms exposed to a persistently elevated temperature relative to baseline incubations, while temperature did not influence AOBs. The concentration of soil ammonium (NH4+) decreased significantly at higher temperatures subsequent to an initial increase, possibly due to higher conversion rates of NH4+ to nitrate by nitrifying bacteria. We show that higher soil temperatures may reduce viable microbial biomass in cold environments but stimulate their activity over a short period.
Collapse
Affiliation(s)
- Sebastian Barnard
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, Natural Sciences 2 Building, University of Pretoria, Pretoria, 0028, South Africa
| | - Marc W Van Goethem
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, Natural Sciences 2 Building, University of Pretoria, Pretoria, 0028, South Africa
| | - Storme Z de Scally
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, Natural Sciences 2 Building, University of Pretoria, Pretoria, 0028, South Africa
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, Natural Sciences 2 Building, University of Pretoria, Pretoria, 0028, South Africa
| | - Peet Jansen van Rensburg
- Focus Area Human Metabolomics, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa
| | - Sarina Claassens
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa
| | - Thulani P Makhalanyane
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, Natural Sciences 2 Building, University of Pretoria, Pretoria, 0028, South Africa
| |
Collapse
|
9
|
Niederberger TD, Bottos EM, Sohm JA, Gunderson T, Parker A, Coyne KJ, Capone DG, Carpenter EJ, Cary SC. Rapid Microbial Dynamics in Response to an Induced Wetting Event in Antarctic Dry Valley Soils. Front Microbiol 2019; 10:621. [PMID: 31019494 PMCID: PMC6458288 DOI: 10.3389/fmicb.2019.00621] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 03/12/2019] [Indexed: 11/13/2022] Open
Abstract
The cold deserts of the McMurdo Dry Valleys (MDV), Antarctica, host a high level of microbial diversity. Microbial composition and biomass in arid vs. ephemerally wetted regions are distinctly different, with wetted communities representing hot spots of microbial activity that are important zones for biogeochemical cycling. While climatic change is likely to cause wetting in areas not historically subject to wetting events, the responses of microorganisms inhabiting arid soils to water addition is unknown. The purpose of this study was to observe how an associated, yet non-wetted microbial community responds to an extended addition of water. Water from a stream was diverted to an adjacent area of arid soil with changes in microbial composition and activities monitored via molecular and biochemical methods over 7 weeks. The frequency of genetic signatures related to both prokaryotic and eukaryotic organisms adapted to MDV aquatic conditions increased during the limited 7 week period, indicating that the soil community was transitioning into a typical "high-productivity" MDV community. This work is consistent with current predictions that MDV microbial communities in arid regions are highly sensitive to climate change, and further supports the notion that changes in community structure and associated biogeochemical cycling may occur much more rapidly than predicted.
Collapse
Affiliation(s)
- Thomas D Niederberger
- College Earth, Ocean, and Environment, University of Delaware, Lewes, DE, United States
| | - Eric M Bottos
- International Centre for Terrestrial Antarctic Research, School of Science, University of Waikato, Hamilton, New Zealand.,Department of Biological Sciences, Thompson Rivers University, Kamloops, BC, Canada
| | - Jill A Sohm
- Department of Biological Sciences, Wrigley Institute for Environmental Studies, University of Southern California, Los Angeles, CA, United States
| | - Troy Gunderson
- Department of Biological Sciences, Wrigley Institute for Environmental Studies, University of Southern California, Los Angeles, CA, United States
| | - Alex Parker
- Romberg Tiburon Center, San Francisco State University, Tiburon, CA, United States
| | - Kathryn J Coyne
- College Earth, Ocean, and Environment, University of Delaware, Lewes, DE, United States
| | - Douglas G Capone
- Department of Biological Sciences, Wrigley Institute for Environmental Studies, University of Southern California, Los Angeles, CA, United States
| | - Edward J Carpenter
- Romberg Tiburon Center, San Francisco State University, Tiburon, CA, United States
| | - Stephen Craig Cary
- College Earth, Ocean, and Environment, University of Delaware, Lewes, DE, United States.,International Centre for Terrestrial Antarctic Research, School of Science, University of Waikato, Hamilton, New Zealand
| |
Collapse
|
10
|
Feeser KL, Van Horn DJ, Buelow HN, Colman DR, McHugh TA, Okie JG, Schwartz E, Takacs-Vesbach CD. Local and Regional Scale Heterogeneity Drive Bacterial Community Diversity and Composition in a Polar Desert. Front Microbiol 2018; 9:1928. [PMID: 30186257 PMCID: PMC6110917 DOI: 10.3389/fmicb.2018.01928] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/30/2018] [Indexed: 02/01/2023] Open
Abstract
The distribution of organisms in an environment is neither uniform nor random but is instead spatially patterned. The factors that control this patterning are complex and the underlying mechanisms are poorly understood. Soil microbes are critical to ecosystem function but exhibit highly complex distributions and community dynamics due in large part to the scale-dependent effects of environmental heterogeneity. To better understand the impact of environmental heterogeneity on the distribution of soil microbes, we sequenced the 16S rRNA gene from bacterial communities in the microbe-dominated polar desert ecosystem of the McMurdo Dry Valleys (MDV), Antarctica. Significant differences in key edaphic variables and alpha diversity were observed among the three lake basins of the Taylor Valley (Kruskal-Wallis; pH: χ2 = 68.89, P < 0.001, conductivity: χ2 = 35.03, P < 0.001, observed species: χ2 = 7.98, P = 0.019 and inverse Simpson: χ2 = 18.52, P < 0.001) and each basin supported distinctive microbial communities (ANOSIM R = 0.466, P = 0.001, random forest ratio of 14.1). However, relationships between community structure and edaphic characteristics were highly variable and contextual, ranging in magnitude and direction across regional, basin, and local scales. Correlations among edaphic factors (pH and soil conductivity) and the relative abundance of specific phyla were most pronounced along local environmental gradients in the Lake Fryxell basin where Acidobacteria, Bacteroidetes, and Proteobacteria declined while Deinococcus-Thermus and Gemmatimonadetes increased with soil conductivity (all P < 0.1). Species richness was most strongly related to the soil conductivity gradient present within this study system. We suggest that the relative importance of pH versus soil conductivity in structuring microbial communities is related to the length of edaphic gradients and the spatial scale of sampling. These results highlight the importance of conducting studies over large ranges of key environmental gradients and across multiple spatial scales to assess the influence of environmental heterogeneity on the composition and diversity of microbial communities.
Collapse
Affiliation(s)
- Kelli L. Feeser
- Department of Biology, University of New Mexico, Albuquerque, NM, United States
| | - David J. Van Horn
- Department of Biology, University of New Mexico, Albuquerque, NM, United States
| | - Heather N. Buelow
- Department of Biology, University of New Mexico, Albuquerque, NM, United States
| | - Daniel R. Colman
- Department of Biology, University of New Mexico, Albuquerque, NM, United States
| | - Theresa A. McHugh
- Department of Biological Sciences, Colorado Mesa University, Grand Junction, CO, United States
| | - Jordan G. Okie
- School of Life Sciences, School of Earth and Space Exploration, Arizona State University, Tempe, AZ, United States
| | - Egbert Schwartz
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, United States
| | | |
Collapse
|
11
|
Pessi IS, Lara Y, Durieu B, Maalouf PDC, Verleyen E, Wilmotte A. Community structure and distribution of benthic cyanobacteria in Antarctic lacustrine microbial mats. FEMS Microbiol Ecol 2018; 94:4935156. [DOI: 10.1093/femsec/fiy042] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 03/13/2018] [Indexed: 12/22/2022] Open
Affiliation(s)
- Igor S Pessi
- InBioS—Centre for Protein Engineering, University of Liège, Allée du Six Août 13, B6a, Quartier Agora, Sart-Tilman, 4000 Liège, Belgium
| | - Yannick Lara
- InBioS—Centre for Protein Engineering, University of Liège, Allée du Six Août 13, B6a, Quartier Agora, Sart-Tilman, 4000 Liège, Belgium
| | - Benoit Durieu
- InBioS—Centre for Protein Engineering, University of Liège, Allée du Six Août 13, B6a, Quartier Agora, Sart-Tilman, 4000 Liège, Belgium
| | - Pedro de C Maalouf
- InBioS—Centre for Protein Engineering, University of Liège, Allée du Six Août 13, B6a, Quartier Agora, Sart-Tilman, 4000 Liège, Belgium
| | - Elie Verleyen
- Research Group Protistology and Aquatic Ecology, Department of Biology, Ghent University, Campus Sterre, Krijgslaan 281-S8, 9000 Gent, Belgium
| | - Annick Wilmotte
- InBioS—Centre for Protein Engineering, University of Liège, Allée du Six Août 13, B6a, Quartier Agora, Sart-Tilman, 4000 Liège, Belgium
| |
Collapse
|
12
|
Adriaenssens EM, Kramer R, Van Goethem MW, Makhalanyane TP, Hogg I, Cowan DA. Environmental drivers of viral community composition in Antarctic soils identified by viromics. MICROBIOME 2017; 5:83. [PMID: 28724405 PMCID: PMC5518109 DOI: 10.1186/s40168-017-0301-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 07/06/2017] [Indexed: 05/18/2023]
Abstract
BACKGROUND The Antarctic continent is considered the coldest and driest place on earth with simple ecosystems, devoid of higher plants. Soils in the ice-free regions of Antarctica are known to harbor a wide range of microorganisms from primary producers to grazers, yet their ecology and particularly the role of viruses is poorly understood. In this study, we examined the virus community structures of 14 soil samples from the Mackay Glacier region. METHODS Viral communities were extracted from soil and the dsDNA was extracted, amplified using single-primer amplification, and sequenced using the Ion Torrent Proton platform. Metadata on soil physico-chemistry was collected from all sites. Both read and contig datasets were analyzed with reference-independent and reference-dependent methods to assess viral community structures and the influence of environmental parameters on their distribution. RESULTS We observed a high heterogeneity in virus signatures, independent of geographical proximity. Tailed bacteriophages were dominant in all samples, but the incidences of the affiliated families Siphoviridae and Myoviridae were inversely correlated, suggesting direct competition for hosts. Viruses of the families Phycodnaviridae and Mimiviridae were present at significant levels in high-diversity soil samples and were found to co-occur, implying little competition between them. Combinations of soil factors, including pH, calcium content, and site altitude, were found to be the main drivers of viral community structure. CONCLUSIONS The pattern of viral community structure with higher levels of diversity at lower altitude and pH, and co-occurring viral families, suggests that these cold desert soil viruses interact with each other, the host, and the environment in an intricate manner, playing a potentially crucial role in maintaining host diversity and functioning of the microbial ecosystem in the extreme environments of Antarctic soil.
Collapse
Affiliation(s)
- Evelien M. Adriaenssens
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB UK
| | - Rolf Kramer
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
| | - Marc W. Van Goethem
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
| | - Thulani P. Makhalanyane
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
| | - Ian Hogg
- School of Science, University of Waikato, Hamilton, New Zealand
- Polar Knowledge Canada, 170 Laurier Avenue West, Ottawa, Ontario K1P 5V5 Canada
| | - Don A. Cowan
- Centre for Microbial Ecology and Genomics, University of Pretoria, Natural Sciences Building II, Private Bag X20, Hatfield, 0028 South Africa
| |
Collapse
|
13
|
Wei STS, Lacap-Bugler DC, Lau MCY, Caruso T, Rao S, de Los Rios A, Archer SK, Chiu JMY, Higgins C, Van Nostrand JD, Zhou J, Hopkins DW, Pointing SB. Taxonomic and Functional Diversity of Soil and Hypolithic Microbial Communities in Miers Valley, McMurdo Dry Valleys, Antarctica. Front Microbiol 2016; 7:1642. [PMID: 27812351 PMCID: PMC5071352 DOI: 10.3389/fmicb.2016.01642] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 10/03/2016] [Indexed: 12/04/2022] Open
Abstract
The McMurdo Dry Valleys of Antarctica are an extreme polar desert. Mineral soils support subsurface microbial communities and translucent rocks support development of hypolithic communities on ventral surfaces in soil contact. Despite significant research attention, relatively little is known about taxonomic and functional diversity or their inter-relationships. Here we report a combined diversity and functional interrogation for soil and hypoliths of the Miers Valley in the McMurdo Dry Valleys of Antarctica. The study employed 16S rRNA fingerprinting and high throughput sequencing combined with the GeoChip functional microarray. The soil community was revealed as a highly diverse reservoir of bacterial diversity dominated by actinobacteria. Hypolithic communities were less diverse and dominated by cyanobacteria. Major differences in putative functionality were that soil communities displayed greater diversity in stress tolerance and recalcitrant substrate utilization pathways, whilst hypolithic communities supported greater diversity of nutrient limitation adaptation pathways. A relatively high level of functional redundancy in both soil and hypoliths may indicate adaptation of these communities to fluctuating environmental conditions.
Collapse
Affiliation(s)
- Sean T S Wei
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology Auckland, New Zealand
| | - Donnabella C Lacap-Bugler
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology Auckland, New Zealand
| | - Maggie C Y Lau
- Department of Geosciences, Princeton University Princeton, NJ, USA
| | - Tancredi Caruso
- School of Biological Sciences, Queen's University Belfast Belfast, Northern Ireland
| | - Subramanya Rao
- Department of Health Technology and Informatics, Hong Kong Polytechnic University Hong Kong, China
| | - Asunción de Los Rios
- Departamento de Biogeoquímica y Ecología Microbiana, Museo Nacional de Ciencias Naturales Madrid, Spain
| | - Stephen K Archer
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology Auckland, New Zealand
| | - Jill M Y Chiu
- Department of Biology, Hong Kong Baptist University Hong Kong, China
| | - Colleen Higgins
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology Auckland, New Zealand
| | - Joy D Van Nostrand
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma Norman, OK, USA
| | - Jizhong Zhou
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of OklahomaNorman, OK, USA; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua UniversityBeijing, China; Earth Sciences Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA
| | - David W Hopkins
- School of Agriculture, Food and Environment, The Royal Agricultural University Gloucestershire, UK
| | - Stephen B Pointing
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of TechnologyAuckland, New Zealand; Institute of Nature and Environmental Technology, Kanazawa UniversityKanazawa, Japan
| |
Collapse
|
14
|
Buelow HN, Winter AS, Van Horn DJ, Barrett JE, Gooseff MN, Schwartz E, Takacs-Vesbach CD. Microbial Community Responses to Increased Water and Organic Matter in the Arid Soils of the McMurdo Dry Valleys, Antarctica. Front Microbiol 2016; 7:1040. [PMID: 27486436 PMCID: PMC4947590 DOI: 10.3389/fmicb.2016.01040] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/21/2016] [Indexed: 11/27/2022] Open
Abstract
The soils of the McMurdo Dry Valleys, Antarctica are an extreme polar desert, inhabited exclusively by microscopic taxa. This region is on the threshold of anticipated climate change, with glacial melt, permafrost thaw, and the melting of massive buried ice increasing liquid water availability and mobilizing soil nutrients. Experimental water and organic matter (OM) amendments were applied to investigate how these climate change effects may impact the soil communities. To identify active taxa and their functions, total community RNA transcripts were sequenced and annotated, and amended soils were compared with unamended control soils using differential abundance and expression analyses. Overall, taxonomic diversity declined with amendments of water and OM. The domain Bacteria increased with both amendments while Eukaryota declined from 38% of all taxa in control soils to 8 and 11% in water and OM amended soils, respectively. Among bacterial phyla, Actinobacteria (59%) dominated water-amended soils and Firmicutes (45%) dominated OM amended soils. Three bacterial phyla (Actinobacteria, Proteobacteria, and Firmicutes) were primarily responsible for the observed positive functional responses, while eukaryotic taxa experienced the majority (27 of 34) of significant transcript losses. These results indicated that as climate changes in this region, a replacement of endemic taxa adapted to dry, oligotrophic conditions by generalist, copiotrophic taxa is likely.
Collapse
Affiliation(s)
- Heather N Buelow
- Department of Biology, University of New Mexico Albuquerque, NM, USA
| | - Ara S Winter
- Department of Biology, University of New Mexico Albuquerque, NM, USA
| | - David J Van Horn
- Department of Biology, University of New Mexico Albuquerque, NM, USA
| | - John E Barrett
- Department of Biological Sciences, Virginia Tech Blacksburg, VA, USA
| | - Michael N Gooseff
- Department of Civil, Architectural, and Environmental Engineering, Institute of Arctic and Alpine Research, University of Colorado Boulder Boulder, CO, USA
| | - Egbert Schwartz
- Department of Biological Sciences, Northern Arizona University Flagstaff, AZ, USA
| | | |
Collapse
|
15
|
Aliyu H, De Maayer P, Cowan D. The genome of the Antarctic polyextremophileNesterenkoniasp. AN1 reveals adaptive strategies for survival under multiple stress conditions. FEMS Microbiol Ecol 2016; 92:fiw032. [DOI: 10.1093/femsec/fiw032] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2016] [Indexed: 01/18/2023] Open
|
16
|
Nearing the cold-arid limits of microbial life in permafrost of an upper dry valley, Antarctica. ISME JOURNAL 2016; 10:1613-24. [PMID: 27323892 PMCID: PMC4918446 DOI: 10.1038/ismej.2015.239] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 10/12/2015] [Accepted: 11/20/2015] [Indexed: 11/11/2022]
Abstract
Some of the coldest and driest permafrost soils on Earth are located in the high-elevation McMurdo Dry Valleys (MDVs) of Antarctica, but little is known about the permafrost microbial communities other than that microorganisms are present in these valleys. Here, we describe the microbiology and habitable conditions of highly unique dry and ice-cemented permafrost in University Valley, one of the coldest and driest regions in the MDVs (1700 m above sea level; mean temperature −23 °C; no degree days above freezing), where the ice in permafrost originates from vapour deposition rather than liquid water. We found that culturable and total microbial biomass in University Valley was extremely low, and microbial activity under ambient conditions was undetectable. Our results contrast with reports from the lower-elevation Dry Valleys and Arctic permafrost soils where active microbial populations are found, suggesting that the combination of severe cold, aridity, oligotrophy of University Valley permafrost soils severely limit microbial activity and survival.
Collapse
|
17
|
Niederberger TD, Sohm JA, Gunderson T, Tirindelli J, Capone DG, Carpenter EJ, Cary SC. Carbon-Fixation Rates and Associated Microbial Communities Residing in Arid and Ephemerally Wet Antarctic Dry Valley Soils. Front Microbiol 2015; 6:1347. [PMID: 26696969 PMCID: PMC4673872 DOI: 10.3389/fmicb.2015.01347] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 11/16/2015] [Indexed: 11/13/2022] Open
Abstract
Carbon-fixation is a critical process in severely oligotrophic Antarctic Dry Valley (DV) soils and may represent the major source of carbon in these arid environments. However, rates of C-fixation in DVs are currently unknown and the microorganisms responsible for these activities unidentified. In this study, C-fixation rates measured in the bulk arid soils (<5% moisture) ranged from below detection limits to ∼12 nmol C/cc/h. Rates in ephemerally wet soils ranged from ∼20 to 750 nmol C/cc/h, equating to turnover rates of ∼7-140 days, with lower rates in stream-associated soils as compared to lake-associated soils. Sequencing of the large subunit of RuBisCO (cbbL) in these soils identified green-type sequences dominated by the 1B cyanobacterial phylotype in both arid and wet soils including the RNA fraction of the wet soil. Red-type cbbL genes were dominated by 1C actinobacterial phylotypes in arid soils, with wetted soils containing nearly equal proportions of 1C (actinobacterial and proteobacterial signatures) and 1D (algal) phylotypes. Complementary 16S rRNA and 18S rRNA gene sequencing also revealed distinct differences in community structure between biotopes. This study is the first of its kind to examine C-fixation rates in DV soils and the microorganisms potentially responsible for these activities.
Collapse
Affiliation(s)
| | - Jill A. Sohm
- Wrigley Institute of Environmental Studies and Department of Biological Science, University of Southern CaliforniaLos Angeles, CA, USA
| | - Troy Gunderson
- Wrigley Institute of Environmental Studies and Department of Biological Science, University of Southern CaliforniaLos Angeles, CA, USA
| | - Joëlle Tirindelli
- Romberg Tiburon Center, San Francisco State UniversityTiburon, CA, USA
| | - Douglas G. Capone
- Wrigley Institute of Environmental Studies and Department of Biological Science, University of Southern CaliforniaLos Angeles, CA, USA
| | | | - S. Craig Cary
- College of Marine and Earth Sciences, University of DelawareLewes, DE, USA
- International Centre for Terrestrial Antarctic Research, University of WaikatoHamilton, New Zealand
| |
Collapse
|
18
|
Temperature-related activity of Gomphiocephalus hodgsoni (Collembola) mitochondrial DNA (COI) haplotypes in Taylor Valley, Antarctica. Polar Biol 2015. [DOI: 10.1007/s00300-015-1788-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
19
|
Niederberger TD, Sohm JA, Gunderson TE, Parker AE, Tirindelli J, Capone DG, Carpenter EJ, Cary SC. Microbial community composition of transiently wetted Antarctic Dry Valley soils. Front Microbiol 2015; 6:9. [PMID: 25674080 PMCID: PMC4309182 DOI: 10.3389/fmicb.2015.00009] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/05/2015] [Indexed: 11/13/2022] Open
Abstract
During the summer months, wet (hyporheic) soils associated with ephemeral streams and lake edges in the Antarctic Dry Valleys (DVs) become hotspots of biological activity and are hypothesized to be an important source of carbon and nitrogen for arid DV soils. Recent research in the DV has focused on the geochemistry and microbial ecology of lakes and arid soils, with substantially less information being available on hyporheic soils. Here, we determined the unique properties of hyporheic microbial communities, resolved their relationship to environmental parameters and compared them to archetypal arid DV soils. Generally, pH increased and chlorophyll a concentrations decreased along transects from wet to arid soils (9.0 to ~7.0 for pH and ~0.8 to ~5 μg/cm3 for chlorophyll a, respectively). Soil water content decreased to below ~3% in the arid soils. Community fingerprinting-based principle component analyses revealed that bacterial communities formed distinct clusters specific to arid and wet soils; however, eukaryotic communities that clustered together did not have similar soil moisture content nor did they group together based on sampling location. Collectively, rRNA pyrosequencing indicated a considerably higher abundance of Cyanobacteria in wet soils and a higher abundance of Acidobacterial, Actinobacterial, Deinococcus/Thermus, Bacteroidetes, Firmicutes, Gemmatimonadetes, Nitrospira, and Planctomycetes in arid soils. The two most significant differences at the genus level were Gillisia signatures present in arid soils and chloroplast signatures related to Streptophyta that were common in wet soils. Fungal dominance was observed in arid soils and Viridiplantae were more common in wet soils. This research represents an in-depth characterization of microbial communities inhabiting wet DV soils. Results indicate that the repeated wetting of hyporheic zones has a profound impact on the bacterial and eukaryotic communities inhabiting in these areas.
Collapse
Affiliation(s)
| | - Jill A Sohm
- Wrigley Institute for Environmental Studies and Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Troy E Gunderson
- Wrigley Institute for Environmental Studies and Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Alexander E Parker
- Romberg Tiburon Center for Environmental Studies, San Francisco State University Tiburon, CA, USA
| | - Joëlle Tirindelli
- Romberg Tiburon Center for Environmental Studies, San Francisco State University Tiburon, CA, USA
| | - Douglas G Capone
- Wrigley Institute for Environmental Studies and Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Edward J Carpenter
- Romberg Tiburon Center for Environmental Studies, San Francisco State University Tiburon, CA, USA
| | - Stephen C Cary
- College of Marine and Earth Sciences, University of Delaware Lewes, DE, USA ; School of Science, University of Waikato Hamilton, New Zealand
| |
Collapse
|
20
|
Dreesens LL, Lee CK, Cary SC. The Distribution and Identity of Edaphic Fungi in the McMurdo Dry Valleys. BIOLOGY 2014; 3:466-83. [PMID: 25079129 PMCID: PMC4192622 DOI: 10.3390/biology3030466] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/14/2014] [Accepted: 07/16/2014] [Indexed: 11/30/2022]
Abstract
Contrary to earlier assumptions, molecular evidence has demonstrated the presence of diverse and localized soil bacterial communities in the McMurdo Dry Valleys of Antarctica. Meanwhile, it remains unclear whether fungal signals so far detected in Dry Valley soils using both culture-based and molecular techniques represent adapted and ecologically active biomass or spores transported by wind. Through a systematic and quantitative molecular survey, we identified significant heterogeneities in soil fungal communities across the Dry Valleys that robustly correlate with heterogeneities in soil physicochemical properties. Community fingerprinting analysis and 454 pyrosequencing of the fungal ribosomal intergenic spacer region revealed different levels of heterogeneity in fungal diversity within individual Dry Valleys and a surprising abundance of Chytridiomycota species, whereas previous studies suggested that Dry Valley soils were dominated by Ascomycota and Basidiomycota. Critically, we identified significant differences in fungal community composition and structure of adjacent sites with no obvious barrier to aeolian transport between them. These findings suggest that edaphic fungi of the Antarctic Dry Valleys are adapted to local environments and represent an ecologically relevant (and possibly important) heterotrophic component of the ecosystem.
Collapse
Affiliation(s)
- Lisa L Dreesens
- International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton 3216, New Zealand.
| | - Charles K Lee
- International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton 3216, New Zealand.
| | - S Craig Cary
- International Centre for Terrestrial Antarctic Research, University of Waikato, Hamilton 3216, New Zealand.
| |
Collapse
|
21
|
Cowan DA, Makhalanyane TP, Dennis PG, Hopkins DW. Microbial ecology and biogeochemistry of continental Antarctic soils. Front Microbiol 2014; 5:154. [PMID: 24782842 PMCID: PMC3988359 DOI: 10.3389/fmicb.2014.00154] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/22/2014] [Indexed: 11/13/2022] Open
Abstract
The Antarctica Dry Valleys are regarded as the coldest hyperarid desert system on Earth. While a wide variety of environmental stressors including very low minimum temperatures, frequent freeze-thaw cycles and low water availability impose severe limitations to life, suitable niches for abundant microbial colonization exist. Antarctic desert soils contain much higher levels of microbial diversity than previously thought. Edaphic niches, including cryptic and refuge habitats, microbial mats and permafrost soils all harbor microbial communities which drive key biogeochemical cycling processes. For example, lithobionts (hypoliths and endoliths) possess a genetic capacity for nitrogen and carbon cycling, polymer degradation, and other system processes. Nitrogen fixation rates of hypoliths, as assessed through acetylene reduction assays, suggest that these communities are a significant input source for nitrogen into these oligotrophic soils. Here we review aspects of microbial diversity in Antarctic soils with an emphasis on functionality and capacity. We assess current knowledge regarding adaptations to Antarctic soil environments and highlight the current threats to Antarctic desert soil communities.
Collapse
Affiliation(s)
- Don A Cowan
- Department of Genetics, Centre for Microbial Ecology and Genetics, University of Pretoria Pretoria, South Africa
| | - Thulani P Makhalanyane
- Department of Genetics, Centre for Microbial Ecology and Genetics, University of Pretoria Pretoria, South Africa
| | - Paul G Dennis
- School of Agriculture and Food Sciences, The University of Queensland Brisbane, QLD, Australia
| | - David W Hopkins
- School of Life Sciences, Heriot-Watt University Edinburgh, UK
| |
Collapse
|
22
|
Brabyn L, Zawar-Reza P, Stichbury G, Cary C, Storey B, Laughlin DC, Katurji M. Accuracy assessment of land surface temperature retrievals from Landsat 7 ETM + in the Dry Valleys of Antarctica using iButton temperature loggers and weather station data. ENVIRONMENTAL MONITORING AND ASSESSMENT 2014; 186:2619-2628. [PMID: 24366817 DOI: 10.1007/s10661-013-3565-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 11/19/2013] [Indexed: 06/03/2023]
Abstract
The McMurdo Dry Valleys of Antarctica are the largest snow/ice-free regions on this vast continent, comprising 1% of the land mass. Due to harsh environmental conditions, the valleys are bereft of any vegetation. Land surface temperature is a key determinate of microclimate and a driver for sensible and latent heat fluxes of the surface. The Dry Valleys have been the focus of ecological studies as they arguably provide the simplest trophic structure suitable for modelling. In this paper, we employ a validation method for land surface temperatures obtained from Landsat 7 ETM + imagery and compared with in situ land surface temperature data collected from four transects totalling 45 iButtons. A single meteorological station was used to obtain a better understanding of daily and seasonal cycles in land surface temperatures. Results show a good agreement between the iButton and the Landsat 7 ETM + product for clear sky cases. We conclude that Landsat 7 ETM + derived land surface temperatures can be used at broad spatial scales for ecological and meteorological research.
Collapse
Affiliation(s)
- Lars Brabyn
- Geography, Tourism and Environmental Planning, University of Waikato, Hamilton, New Zealand,
| | | | | | | | | | | | | |
Collapse
|
23
|
Bottos EM, Woo AC, Zawar-Reza P, Pointing SB, Cary SC. Airborne bacterial populations above desert soils of the McMurdo Dry Valleys, Antarctica. MICROBIAL ECOLOGY 2014; 67:120-8. [PMID: 24121801 PMCID: PMC3907674 DOI: 10.1007/s00248-013-0296-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 09/17/2013] [Indexed: 05/15/2023]
Abstract
Bacteria are assumed to disperse widely via aerosolized transport due to their small size and resilience. The question of microbial endemicity in isolated populations is directly related to the level of airborne exogenous inputs, yet this has proven hard to identify. The ice-free terrestrial ecosystem of Antarctica, a geographically and climatically isolated continent, was used to interrogate microbial bio-aerosols in relation to the surrounding ecology and climate. High-throughput sequencing of bacterial ribosomal RNA (rRNA) genes was combined with analyses of climate patterns during an austral summer. In general terms, the aerosols were dominated by Firmicutes, whereas surrounding soils supported Actinobacteria-dominated communities. The most abundant taxa were also common to aerosols from other continents, suggesting that a distinct bio-aerosol community is widely dispersed. No evidence for significant marine input to bioaerosols was found at this maritime valley site, instead local influence was largely from nearby volcanic sources. Back trajectory analysis revealed transport of incoming regional air masses across the Antarctic Plateau, and this is envisaged as a strong selective force. It is postulated that local soil microbial dispersal occurs largely via stochastic mobilization of mineral soil particulates.
Collapse
Affiliation(s)
- Eric M. Bottos
- />International Centre for Terrestrial Antarctic Research, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
- />Department of Biological Sciences, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
| | - Anthony C. Woo
- />Sorbonne Paris Cité, Faculté de Médecine, Université Paris Descartes, Paris Descartes, 24 rue du Faubourg Saint-Jacques, 75014 Paris, France
| | - Peyman Zawar-Reza
- />International Centre for Terrestrial Antarctic Research, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
- />Department of Geography, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Stephen B. Pointing
- />International Centre for Terrestrial Antarctic Research, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
- />Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology, Private Bag 92006, Auckland, 1142 New Zealand
| | - Stephen C. Cary
- />International Centre for Terrestrial Antarctic Research, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
- />Department of Biological Sciences, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
| |
Collapse
|
24
|
Sokol ER, Herbold CW, Lee CK, Cary SC, Barrett JE. Local and regional influences over soil microbial metacommunities in the Transantarctic Mountains. Ecosphere 2013. [DOI: 10.1890/es13-00136.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
25
|
Abstract
The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are critically at risk from climate change. The terrestrial landscape is dominated by oligotrophic mineral soils and extensive exposed rocky surfaces where biota are largely restricted to microbial communities, although their ability to perform the majority of geobiological processes has remained largely uncharacterized. Here, we identified functional traits that drive microbial survival and community assembly, using a metagenomic approach with GeoChip-based functional gene arrays to establish metabolic capabilities in communities inhabiting soil and rock surface niches in McKelvey Valley. Major pathways in primary metabolism were identified, indicating significant plasticity in autotrophic, heterotrophic, and diazotrophic strategies supporting microbial communities. This represents a major advance beyond biodiversity surveys in that we have now identified how putative functional ecology drives microbial community assembly. Significant differences were apparent between open soil, hypolithic, chasmoendolithic, and cryptoendolithic communities. A suite of previously unappreciated Antarctic microbial stress response pathways, thermal, osmotic, and nutrient limitation responses were identified and related to environmental stressors, offering tangible clues to the mechanisms behind the enduring success of microorganisms in this seemingly inhospitable terrain. Rocky substrates exposed to larger fluctuations in environmental stress supported greater functional diversity in stress-response pathways than soils. Soils comprised a unique reservoir of genes involved in transformation of organic hydrocarbons and lignin-like degradative pathways. This has major implications for the evolutionary origin of the organisms, turnover of recalcitrant substrates in Antarctic soils, and predicting future responses to anthropogenic pollution.
Collapse
|
26
|
O’Neill T, Balks M, Stevenson B, López-Martínez J, Aislabie J, Rhodes P. The short-term effects of surface soil disturbance on soil bacterial community structure at an experimental site near Scott Base, Antarctica. Polar Biol 2013. [DOI: 10.1007/s00300-013-1322-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
27
|
Verde C, di Prisco G, Giordano D, Russo R, Anderson D, Cowan D. Antarctic psychrophiles: models for understanding the molecular basis of survival at low temperature and responses to climate change. ACTA ACUST UNITED AC 2012. [DOI: 10.1080/14888386.2012.706703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
28
|
Influence of soil properties on the distribution of Deschampsia antarctica on King George Island, Maritime Antarctica. Polar Biol 2012. [DOI: 10.1007/s00300-012-1213-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
29
|
Niederberger TD, Sohm JA, Tirindelli J, Gunderson T, Capone DG, Carpenter EJ, Cary SC. Diverse and highly active diazotrophic assemblages inhabit ephemerally wetted soils of the Antarctic Dry Valleys. FEMS Microbiol Ecol 2012; 82:376-90. [PMID: 22500944 DOI: 10.1111/j.1574-6941.2012.01390.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 04/04/2012] [Accepted: 04/10/2012] [Indexed: 11/28/2022] Open
Abstract
Eolian transport of biomass from ephemerally wetted soils, associated with summer glacial meltwater runoffs and lake edges, to low-productivity areas of the Antarctic Dry Valleys (DV) has been postulated to be an important source of organic matter (fixed nitrogen and fixed carbon) to the entire DV ecosystem. However, descriptions and identification of the microbial members responsible for N(2) fixation within these wetted sites are limited. In this study, N(2) fixers from wetted soils were identified by direct nifH gene sequencing and their in situ N(2) fixation activities documented via acetylene reduction and RNA-based quantitative PCR assays. Shannon-index nifH diversity levels ranged between 1.8 and 2.6 and included the expected cyanobacterial signatures and a large number of phylotypes related to the gamma-, beta-, alpha-, and delta-proteobacteria. N(2) fixation rates ranged between approximately 0.5 and 6 nmol N cm(-3) h(-1) with measurements indicating that approximately 50% of this activity was linked with sulfate reduction at some sites. Comparisons with proximal dry soils also suggested that these communities are not ubiquitously distributed, and conditions unrelated to moisture content may define the composition, diversity, or habitat suitability of the microbial communities within wetted soils of the DVs.
Collapse
|
30
|
Stomeo F, Makhalanyane TP, Valverde A, Pointing SB, Stevens MI, Cary CS, Tuffin MI, Cowan DA. Abiotic factors influence microbial diversity in permanently cold soil horizons of a maritime-associated Antarctic Dry Valley. FEMS Microbiol Ecol 2012; 82:326-40. [DOI: 10.1111/j.1574-6941.2012.01360.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 03/06/2012] [Accepted: 03/06/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- Francesca Stomeo
- Institute for Microbial Biotechnology and Metagenomics; University of the Western Cape; Cape Town; South Africa
| | - Thulani P. Makhalanyane
- Institute for Microbial Biotechnology and Metagenomics; University of the Western Cape; Cape Town; South Africa
| | - Angel Valverde
- Institute for Microbial Biotechnology and Metagenomics; University of the Western Cape; Cape Town; South Africa
| | - Stephen B. Pointing
- School of Biological Sciences; The University of Hong Kong; Hong Kong; China
| | - Mark I. Stevens
- South Australian Museum and School of Earth and Environmental Sciences; University of Adelaide; Adelaide; SA; Australia
| | - Craig S. Cary
- Department of Biological Sciences; University of Waikato; Hamilton; New Zealand
| | - Marla I. Tuffin
- Institute for Microbial Biotechnology and Metagenomics; University of the Western Cape; Cape Town; South Africa
| | - Don A. Cowan
- Institute for Microbial Biotechnology and Metagenomics; University of the Western Cape; Cape Town; South Africa
| |
Collapse
|
31
|
Tiao G, Lee CK, McDonald IR, Cowan DA, Cary SC. Rapid microbial response to the presence of an ancient relic in the Antarctic Dry Valleys. Nat Commun 2012; 3:660. [PMID: 22314356 DOI: 10.1038/ncomms1645] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 12/14/2011] [Indexed: 11/09/2022] Open
Abstract
The extreme cold and aridity of the Antarctic McMurdo Dry Valleys have led to the longstanding belief that metabolic rates of soil microbiota are negligible, and that ecosystem changes take place over millennia. Here we report the first direct experimental evidence that soil microbial communities undergo rapid and lasting changes in response to contemporary environmental conditions. Mummified seals, curious natural artifacts found scattered throughout Dry Valleys, alter their underlying soil environment by stabilizing temperatures, elevating relative humidity and reducing ultraviolet exposure. In a unique, multi-year mummified seal transplantation experiment, we found that endemic Dry Valley microbial communities responded to these changes within 3 years, resulting in a sevenfold increase in CO(2) flux and a significant reduction in biodiversity. These findings challenge prevailing ideas about Antarctic Dry Valley ecosystems and indicate that current and future environmental conditions may strongly influence the ecology of the dominant biota in the Dry Valleys.
Collapse
Affiliation(s)
- Grace Tiao
- The International Centre for Terrestrial Antarctic Research, Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
| | | | | | | | | |
Collapse
|
32
|
Lee CK, Barbier BA, Bottos EM, McDonald IR, Cary SC. The Inter-Valley Soil Comparative Survey: the ecology of Dry Valley edaphic microbial communities. ISME JOURNAL 2011; 6:1046-57. [PMID: 22170424 DOI: 10.1038/ismej.2011.170] [Citation(s) in RCA: 165] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Recent applications of molecular genetics to edaphic microbial communities of the McMurdo Dry Valleys and elsewhere have rejected a long-held belief that Antarctic soils contain extremely limited microbial diversity. The Inter-Valley Soil Comparative Survey aims to elucidate the factors shaping these unique microbial communities and their biogeography by integrating molecular genetic approaches with biogeochemical analyses. Although the microbial communities of Dry Valley soils may be complex, there is little doubt that the ecosystem's food web is relatively simple, and evidence suggests that physicochemical conditions may have the dominant role in shaping microbial communities. To examine this hypothesis, bacterial communities from representative soil samples collected in four geographically disparate Dry Valleys were analyzed using molecular genetic tools, including pyrosequencing of 16S rRNA gene PCR amplicons. Results show that the four communities are structurally and phylogenetically distinct, and possess significantly different levels of diversity. Strikingly, only 2 of 214 phylotypes were found in all four valleys, challenging a widespread assumption that the microbiota of the Dry Valleys is composed of a few cosmopolitan species. Analysis of soil geochemical properties indicated that salt content, alongside altitude and Cu(2+), was significantly correlated with differences in microbial communities. Our results indicate that the microbial ecology of Dry Valley soils is highly localized and that physicochemical factors potentially have major roles in shaping the microbiology of ice-free areas of Antarctica. These findings hint at links between Dry Valley glacial geomorphology and microbial ecology, and raise previously unrecognized issues related to environmental management of this unique ecosystem.
Collapse
Affiliation(s)
- Charles K Lee
- Department of Biological Sciences, University of Waikato, Hamilton, New Zealand
| | | | | | | | | |
Collapse
|
33
|
Zeglin LH, Dahm CN, Barrett JE, Gooseff MN, Fitpatrick SK, Takacs-Vesbach CD. Bacterial community structure along moisture gradients in the parafluvial sediments of two ephemeral desert streams. MICROBIAL ECOLOGY 2011; 61:543-556. [PMID: 21153024 DOI: 10.1007/s00248-010-9782-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Accepted: 11/18/2010] [Indexed: 05/30/2023]
Abstract
Microorganisms inhabiting stream sediments mediate biogeochemical processes of importance to both aquatic and terrestrial ecosystems. In deserts, the lateral margins of ephemeral stream channels (parafluvial sediments) are dried and rewetted, creating periodically wet conditions that typically enhance microbial activity. However, the influence of water content on microbial community composition and diversity in desert stream sediments is unclear. We sampled stream margins along gradients of wet to dry sediments, measuring geochemistry and bacterial 16S rRNA gene composition, at streams in both a cold (McMurdo Dry Valleys, Antarctica) and hot (Chihuahuan Desert, New Mexico, USA) desert. Across the gradients, sediment water content spanned a wide range (1.6-37.9% w/w), and conductivity was highly variable (12.3-1,380 μS cm(-2)). Bacterial diversity (at 97% sequence similarity) was high and variable, but did not differ significantly between the hot and cold desert and was not correlated with sediment water content. Instead, conductivity was most strongly related to diversity. Water content was strongly related to bacterial 16S rRNA gene community composition, though samples were distributed in wet and dry clusters rather than as assemblages shifting along a gradient. Phylogenetic analyses showed that many taxa from wet sediments at the hot and cold desert site were related to, respectively, halotolerant Gammaproteobacteria, and one family within the Sphingobacteriales (Bacteroidetes), while dry sediments at both sites contained a high proportion of taxa related to the Acidobacteria. These results suggest that bacterial diversity and composition in desert stream sediments is more strongly affected by hydrology and conductivity than temperature.
Collapse
Affiliation(s)
- Lydia H Zeglin
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | | | | | | | | | | |
Collapse
|
34
|
Cary SC, McDonald IR, Barrett JE, Cowan DA. On the rocks: the microbiology of Antarctic Dry Valley soils. Nat Rev Microbiol 2010; 8:129-38. [DOI: 10.1038/nrmicro2281] [Citation(s) in RCA: 414] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
35
|
|
36
|
Landscape Distribution of Microbial Activity in the McMurdo Dry Valleys: Linked Biotic Processes, Hydrology, and Geochemistry in a Cold Desert Ecosystem. Ecosystems 2009. [DOI: 10.1007/s10021-009-9242-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
37
|
Hopkins DW, Sparrow AD, Gregorich EG, Elberling B, Novis P, Fraser F, Scrimgeour C, Dennis PG, Meier-Augenstein W, Greenfield LG. Isotopic evidence for the provenance and turnover of organic carbon by soil microorganisms in the Antarctic dry valleys. Environ Microbiol 2009; 11:597-608. [DOI: 10.1111/j.1462-2920.2008.01830.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
38
|
Büdel B, Bendix J, Bicker FR, Allan Green TG. DEWFALL AS A WATER SOURCE FREQUENTLY ACTIVATES THE ENDOLITHIC CYANOBACTERIAL COMMUNITIES IN THE GRANITES OF TAYLOR VALLEY, ANTARCTICA(1). JOURNAL OF PHYCOLOGY 2008; 44:1415-1424. [PMID: 27039856 DOI: 10.1111/j.1529-8817.2008.00608.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Endolithic photosynthetic microorganisms like cyanobacteria and algae are well known from savannas and deserts of the world, the high Arctic, and also Antarctic habitats like the Dry Valleys in the Ross Dependency. These endolithic microbial communities are thought to be at the limits of life with reported ages in the order of thousands of years. Here we report on an extensive chasmoendolithic cyanobacterial community inside granite rocks of Mt. Falconer in the lower Taylor Valley, Dry Valleys. On average, the cyanobacterial community was 4.49 ± 0.95 mm below the rock surface, where it formed a blue-green layer. The community was composed mainly of the cyanobacterium Chroococcidiopsis sp., with occasional Cyanothece cf. aeruginosa (Nägeli) Komárek and Nostoc sp. Mean biomass was 168 ± 44 g carbon · m(-2) , and the mean chl a content was 24.3 ± 34.2 mg · m(-2) . In situ chl fluorescence measurements-a relative measure of photosynthetic activity-showed that they were active over long periods each day and also showed activity the next day in the absence of any moisture. Radiocarbon dating gave a relatively young age (175-280 years) for the community. Calculations from microclimate data demonstrated that formation of dew or rime was possible and could frequently activate the cyanobacteria and may explain the younger age of microbial communities at Mt. Falconer compared to older and less active endolithic microorganisms reported earlier from Linnaeus Terrace, a higher altitude region that experiences colder, drier conditions.
Collapse
Affiliation(s)
- Burkhard Büdel
- Department of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyFaculty of Geography, University of Marburg, Deutschhausstraße 10, D-35032 Marburg, GermanyDepartment of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyBiological Sciences, Waikato University, Hamilton, New Zealand Vegetal II, Farmacia Facultad, Universidad Complutense, Madrid, Spain
| | - Jörg Bendix
- Department of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyFaculty of Geography, University of Marburg, Deutschhausstraße 10, D-35032 Marburg, GermanyDepartment of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyBiological Sciences, Waikato University, Hamilton, New Zealand Vegetal II, Farmacia Facultad, Universidad Complutense, Madrid, Spain
| | - Fritz R Bicker
- Department of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyFaculty of Geography, University of Marburg, Deutschhausstraße 10, D-35032 Marburg, GermanyDepartment of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyBiological Sciences, Waikato University, Hamilton, New Zealand Vegetal II, Farmacia Facultad, Universidad Complutense, Madrid, Spain
| | - T G Allan Green
- Department of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyFaculty of Geography, University of Marburg, Deutschhausstraße 10, D-35032 Marburg, GermanyDepartment of Biology, University of Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, GermanyBiological Sciences, Waikato University, Hamilton, New Zealand Vegetal II, Farmacia Facultad, Universidad Complutense, Madrid, Spain
| |
Collapse
|
39
|
Bardgett RD, Richter A, Bol R, Garnett MH, Bäumler R, Xu X, Lopez-Capel E, Manning DA, Hobbs PJ, Hartley IR, Wanek W. Heterotrophic microbial communities use ancient carbon following glacial retreat. Biol Lett 2007; 3:487-90. [PMID: 17609172 PMCID: PMC2391183 DOI: 10.1098/rsbl.2007.0242] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
When glaciers retreat they expose barren substrates that become colonized by organisms, beginning the process of primary succession. Recent studies reveal that heterotrophic microbial communities occur in newly exposed glacial substrates before autotrophic succession begins. This raises questions about how heterotrophic microbial communities function in the absence of carbon inputs from autotrophs. We measured patterns of soil organic matter development and changes in microbial community composition and carbon use along a 150-year chronosequence of a retreating glacier in the Austrian Alps. We found that soil microbial communities of recently deglaciated terrain differed markedly from those of later successional stages, being of lower biomass and higher abundance of bacteria relative to fungi. Moreover, we found that these initial microbial communities used ancient and recalcitrant carbon as an energy source, along with modern carbon. Only after more than 50 years of organic matter accumulation did the soil microbial community change to one supported primarily by modern carbon, most likely from recent plant production. Our findings suggest the existence of an initial stage of heterotrophic microbial community development that precedes autotrophic community assembly and is sustained, in part, by ancient carbon.
Collapse
Affiliation(s)
- Richard D Bardgett
- Institute of Environmental and Natural Sciences, Lancaster UniversityLancaster LA1 4YQ, UK
- Author for correspondence ()
| | - Andreas Richter
- Department of Chemical Ecology and Ecosystem Research, University of Vienna1090 Wien, Austria
| | - Roland Bol
- Institute of Grassland and Environmental Research, North WykeOkehampton, Devon EX20 2SB, UK
| | - Mark H Garnett
- NERC Radiocarbon Laboratory, East KilbrideGlasgow G75 0QF, UK
| | - Rupert Bäumler
- Institute of Geography, University of ErlangenNürnberg, Kochstrasse 4/4, 91054 Erlangen, Germany
| | - Xingliang Xu
- Department of Chemical Ecology and Ecosystem Research, University of Vienna1090 Wien, Austria
| | - Elisa Lopez-Capel
- School of Civil Engineering and Geoscience, University of NewcastleNewcastle-upon-Tyne NE1 7RU, UK
| | - David A.C Manning
- School of Civil Engineering and Geoscience, University of NewcastleNewcastle-upon-Tyne NE1 7RU, UK
| | - Phil J Hobbs
- Institute of Grassland and Environmental Research, North WykeOkehampton, Devon EX20 2SB, UK
| | - Ian R Hartley
- Institute of Environmental and Natural Sciences, Lancaster UniversityLancaster LA1 4YQ, UK
| | - Wolfgang Wanek
- Department of Chemical Ecology and Ecosystem Research, University of Vienna1090 Wien, Austria
| |
Collapse
|
40
|
Yergeau E, Kang S, He Z, Zhou J, Kowalchuk GA. Functional microarray analysis of nitrogen and carbon cycling genes across an Antarctic latitudinal transect. ISME JOURNAL 2007; 1:163-79. [DOI: 10.1038/ismej.2007.24] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|