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Hooper PM, Bass D, Feil EJ, Vincent WF, Lovejoy C, Owen CJ, Tsola SL, Jungblut AD. Arctic cyanobacterial mat community diversity decreases with latitude across the Canadian Arctic. FEMS Microbiol Ecol 2024; 100:fiae067. [PMID: 38653723 DOI: 10.1093/femsec/fiae067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 04/15/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024] Open
Abstract
Cyanobacterial mats are commonly reported as hotspots of microbial diversity across polar environments. These thick, multilayered microbial communities provide a refuge from extreme environmental conditions, with many species able to grow and coexist despite the low allochthonous nutrient inputs. The visibly dominant phototrophic biomass is dependent on internal nutrient recycling by heterotrophic organisms within the mats; however, the specific contribution of heterotrophic protists remains little explored. In this study, mat community diversity was examined along a latitudinal gradient (55-83°N), spanning subarctic taiga, tundra, polar desert, and the High Arctic ice shelves. The prokaryotic and eukaryotic communities were targeted, respectively, by V4 16S ribosomal RNA (rRNA) and V9 18S rRNA gene amplicon high-throughput sequencing. Prokaryotic and eukaryotic richness decreased, in tandem with decreasing temperatures and shorter seasons of light availability, from the subarctic to the High Arctic. Taxonomy-based annotation of the protist community revealed diverse phototrophic, mixotrophic, and heterotrophic genera in all mat communities, with fewer parasitic taxa in High Arctic communities. Co-occurrence network analysis identified greater heterogeneity in eukaryotic than prokaryotic community structure among cyanobacterial mats across the Canadian Arctic. Our findings highlight the sensitivity of microbial eukaryotes to environmental gradients across northern high latitudes.
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Affiliation(s)
- Patrick M Hooper
- Science Department, Natural History Museum, Cromwell Road, London, SW7 5BD, United Kingdom
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom
| | - David Bass
- Science Department, Natural History Museum, Cromwell Road, London, SW7 5BD, United Kingdom
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Barrack Road, Weymouth, DT4 8UB, United Kingdom
- Centre for Sustainable Aquaculture Futures, University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
| | - Edward J Feil
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom
| | - Warwick F Vincent
- Département de Biologie, Takuvik International Research Laboratory and Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, G1V 0A6, Canada
- Centre d'études nordiques (CEN), Université Laval, Québec, QC, G1V 0A6, Canada
| | - Connie Lovejoy
- Département de Biologie, Takuvik International Research Laboratory and Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, G1V 0A6, Canada
- Centre d'études nordiques (CEN), Université Laval, Québec, QC, G1V 0A6, Canada
- Québec Océan, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Christopher J Owen
- UCL Genetics Institute, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Stephania L Tsola
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom
| | - Anne D Jungblut
- Science Department, Natural History Museum, Cromwell Road, London, SW7 5BD, United Kingdom
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2
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Tytgat B, Verleyen E, Sweetlove M, Van den Berge K, Pinseel E, Hodgson DA, Chown SL, Sabbe K, Wilmotte A, Willems A, Vyverman W. Polar lake microbiomes have distinct evolutionary histories. SCIENCE ADVANCES 2023; 9:eade7130. [PMID: 37976353 PMCID: PMC10656066 DOI: 10.1126/sciadv.ade7130] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 10/19/2023] [Indexed: 11/19/2023]
Abstract
Toward the poles, life on land is increasingly dominated by microorganisms, yet the evolutionary origin of polar microbiomes remains poorly understood. Here, we use metabarcoding of Arctic, sub-Antarctic, and Antarctic lacustrine benthic microbial communities to test the hypothesis that high-latitude microbiomes are recruited from a globally dispersing species pool through environmental selection. We demonstrate that taxonomic overlap between the regions is limited within most phyla, even at higher-order taxonomic levels, with unique deep-branching phylogenetic clades being present in each region. We show that local and regional taxon richness and net diversification rate of regionally restricted taxa differ substantially between polar regions in both microeukaryotic and bacterial biota. This suggests that long-term evolutionary divergence resulting from low interhemispheric dispersal and diversification in isolation has been a prominent process shaping present-day polar lake microbiomes. Our findings illuminate the distinctive biogeography of polar lake ecosystems and underscore that conservation efforts should include their unique microbiota.
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Affiliation(s)
- Bjorn Tytgat
- Laboratory of Protistology and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Elie Verleyen
- Laboratory of Protistology and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Maxime Sweetlove
- Laboratory of Protistology and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Koen Van den Berge
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Gent, Belgium
| | - Eveline Pinseel
- Laboratory of Protistology and Aquatic Ecology, Ghent University, Gent, Belgium
- Meise Botanic Garden, Meise, Belgium
| | - Dominic A. Hodgson
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
- Department of Geography, Durham University, Durham, UK
| | - Steven L. Chown
- Securing Antarctica’s Environmental Future, School of Biological Sciences, Monash University, Melbourne, VIC, Australia
| | - Koen Sabbe
- Laboratory of Protistology and Aquatic Ecology, Ghent University, Gent, Belgium
| | - Annick Wilmotte
- InBio-Centre for Protein Engineering, University of Liège, Liège, Belgium
| | - Anne Willems
- Laboratory of Microbiology, Ghent University, Gent, Belgium
| | | | - Wim Vyverman
- Laboratory of Protistology and Aquatic Ecology, Ghent University, Gent, Belgium
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3
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Modeling Virus and Bacteria Populations in Europa’s Subsurface Ocean. Life (Basel) 2022; 12:life12050620. [PMID: 35629289 PMCID: PMC9147769 DOI: 10.3390/life12050620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/15/2022] [Accepted: 04/18/2022] [Indexed: 12/11/2022] Open
Abstract
The search for life in the universe is often informed by the study of “extreme” environments on Earth, which provide analogs for habitable locations in the Solar System, and whose microbial inhabitants may therefore also serve as analogs for potential life forms in extraterrestrial milieus. Recent work has highlighted the ubiquity and importance of viral entities in terrestrial ecosystems, which calls for a greater understanding of the roles that viruses might play in hypothetical extraterrestrial biomes. While some studies have modeled the dynamics of viral and bacterial populations in icy ocean environments on Earth, previous work has yet to apply these findings to icy ocean worlds such as Jupiter’s moon Europa. It is commonly theorized that hydrothermal vents on Europa could produce the necessary reductants for chemosynthesis to take place on the ocean bottom. In the case that Europa’s ocean is a reductant-limited environment, how might reductants and organic matter reach the sub-ice region to power a more easily accessible ecosystem? Here, we propose a ‘viral elevator,’ a mechanism that functions similarly to the ‘viral shunt’ in Earth’s oceans, which could create and shuttle dissolved organic matter (DOM) to a hypothetical sub-ice biosphere through viral carriers. Current models of Europa’s ocean currents and stratification support the movement of DOM to the sub-ice biosphere. We adapt an existing model for bacterial and viral population dynamics in Earth’s Arctic sea ice to Europa and use parameters from various Arctic-based studies as proxies for Europa’s environment. We find that viral burst size has the most significant effect on the virus-to-bacteria ratio (VBR) and system longevity in closed systems (such as brine pockets within Europa’s icy crust), with higher burst sizes clearly increasing both. When applying our model to an open system with an influx of DOM from the viral elevator, we found that a steady-state system is attainable, with resulting sub-ice biofilms on the order of 0.1 mm thick (global equivalent layer). This has implications for future searches for life on Europa, given that life directly under the ice will be easier to detect and observe than life near the ocean bottom.
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4
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Marois C, Girard C, Klanten Y, Vincent WF, Culley AI, Antoniades D. Local Habitat Filtering Shapes Microbial Community Structure in Four Closely Spaced Lakes in the High Arctic. Front Microbiol 2022; 13:779505. [PMID: 35222324 PMCID: PMC8873593 DOI: 10.3389/fmicb.2022.779505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 01/20/2022] [Indexed: 11/13/2022] Open
Abstract
Arctic lakes are experiencing increasingly shorter periods of ice cover due to accelerated warming at northern high latitudes. Given the control of ice cover thickness and duration over many limnological processes, these changes will have pervasive effects. However, due to their remote and extreme locations even first-order data on lake ecology is lacking for many ecosystems. The aim of this study was to characterize and compare the microbial communities of four closely spaced lakes in Stuckberry Valley (northern Ellesmere Island, Canadian Arctic Archipelago), in the coastal margin zone of the Last Ice Area, that differed in their physicochemical, morphological and catchment characteristics. We performed high-throughput amplicon sequencing of the V4 16S rRNA gene to provide inter- and intra-lake comparisons. Two deep (>25 m) and mostly oxygenated lakes showed highly similar community assemblages that were distinct from those of two shallower lakes (<10 m) with anoxic bottom waters. Proteobacteria, Verrucomicrobia, and Planctomycetes were the major phyla present in the four water bodies. One deep lake contained elevated proportions of Cyanobacteria and Thaumarchaeota that distinguished it from the others, while the shallow lakes had abundant communities of predatory bacteria, as well as microbes in their bottom waters that contribute to sulfur and methane cycles. Despite their proximity, our data suggest that local habitat filtering is the primary determinant of microbial diversity in these systems. This study provides the first detailed examination of the microbial assemblages of the Stuckberry lakes system, resulting in new insights into the microbial ecology of the High Arctic.
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Affiliation(s)
- Catherine Marois
- Département de Biochimie, Microbiologie et Bio-Informatique, Université Laval, Québec, QC, Canada
- Centre d’Études Nordiques (CEN), Université Laval, Québec, QC, Canada
- Institut de Biologie Intégrative des Systèmes (IBIS), Université Laval, Québec, QC, Canada
| | - Catherine Girard
- Centre d’Études Nordiques (CEN), Université Laval, Québec, QC, Canada
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Yohanna Klanten
- Centre d’Études Nordiques (CEN), Université Laval, Québec, QC, Canada
- Département de Géographie, Université Laval, Québec, QC, Canada
| | - Warwick F. Vincent
- Centre d’Études Nordiques (CEN), Université Laval, Québec, QC, Canada
- Institut de Biologie Intégrative des Systèmes (IBIS), Université Laval, Québec, QC, Canada
- Département de Biologie, Université Laval, Québec, QC, Canada
| | - Alexander I. Culley
- Département de Biochimie, Microbiologie et Bio-Informatique, Université Laval, Québec, QC, Canada
- Centre d’Études Nordiques (CEN), Université Laval, Québec, QC, Canada
- Institut de Biologie Intégrative des Systèmes (IBIS), Université Laval, Québec, QC, Canada
| | - Dermot Antoniades
- Centre d’Études Nordiques (CEN), Université Laval, Québec, QC, Canada
- Département de Géographie, Université Laval, Québec, QC, Canada
- *Correspondence: Dermot Antoniades,
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5
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Jungblut AD, Raymond F, Dion MB, Moineau S, Mohit V, Nguyen GQ, Déraspe M, Francovic-Fontaine É, Lovejoy C, Culley AI, Corbeil J, Vincent WF. Genomic diversity and CRISPR-Cas systems in the cyanobacterium Nostoc in the High Arctic. Environ Microbiol 2021; 23:2955-2968. [PMID: 33760341 DOI: 10.1111/1462-2920.15481] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 03/22/2021] [Indexed: 11/27/2022]
Abstract
Nostoc (Nostocales, Cyanobacteria) has a global distribution in the Polar Regions. However, the genomic diversity of Nostoc is little known and there are no genomes available for polar Nostoc. Here we carried out the first genomic analysis of the Nostoc commune morphotype with a recent sample from the High Arctic and a herbarium specimen collected during the British Arctic Expedition (1875-76). Comparisons of the polar genomes with 26 present-day non-polar members of the Nostocales family highlighted that there are pronounced genetic variations among Nostoc strains and species. Osmoprotection and other stress genes were found in all Nostoc strains, but the two Arctic strains had markedly higher numbers of biosynthetic gene clusters for uncharacterised non-ribosomal peptide synthetases, suggesting a high diversity of secondary metabolites. Since viral-host interactions contribute to microbial diversity, we analysed the CRISPR-Cas systems in the Arctic and two temperate Nostoc species. There were a large number of unique repeat-spacer arrays in each genome, indicating diverse histories of viral attack. All Nostoc strains had a subtype I-D system, but the polar specimens also showed evidence of a subtype I-B system that has not been previously reported in cyanobacteria, suggesting diverse cyanobacteria-virus interactions in the Arctic.
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Affiliation(s)
- Anne D Jungblut
- Life Sciences Department, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Frédéric Raymond
- Department of Molecular Medicine and Big Data Research Centre, Université Laval, Quebec, QC, G1V 0A6, Canada.,School of Nutrition and Institute on Nutrition and Functional Foods, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Moïra B Dion
- Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Groupe de Recherche en Écologie Buccale, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Sylvain Moineau
- Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Groupe de Recherche en Écologie Buccale, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Vani Mohit
- Centre for Northern Studies (CEN), Université Laval, Quebec City, QC, G1V 0A6, Canada.,Takuvik Joint International Laboratory and Institute of Integrative Biology and Systems, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Département de Biologie, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Guillaume Quang Nguyen
- School of Nutrition and Institute on Nutrition and Functional Foods, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Maxime Déraspe
- Department of Molecular Medicine and Big Data Research Centre, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Élina Francovic-Fontaine
- Department of Molecular Medicine and Big Data Research Centre, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Connie Lovejoy
- Takuvik Joint International Laboratory and Institute of Integrative Biology and Systems, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Département de Biologie, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Québec-Océan, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Alexander I Culley
- Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Groupe de Recherche en Écologie Buccale, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Centre for Northern Studies (CEN), Université Laval, Quebec City, QC, G1V 0A6, Canada.,Takuvik Joint International Laboratory and Institute of Integrative Biology and Systems, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Jacques Corbeil
- Department of Molecular Medicine and Big Data Research Centre, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Warwick F Vincent
- Centre for Northern Studies (CEN), Université Laval, Quebec City, QC, G1V 0A6, Canada.,Takuvik Joint International Laboratory and Institute of Integrative Biology and Systems, Université Laval, Quebec City, QC, G1V 0A6, Canada.,Département de Biologie, Université Laval, Quebec City, QC, G1V 0A6, Canada
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6
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Motaung TE, Peremore C, Wingfield B, Steenkamp E. Plant-associated fungal biofilms-knowns and unknowns. FEMS Microbiol Ecol 2021; 96:5956487. [PMID: 33150944 DOI: 10.1093/femsec/fiaa224] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/03/2020] [Indexed: 02/07/2023] Open
Abstract
Nearly all microbes, including fungi, grow firmly attached to surfaces as a biofilm. Yet, attention toward fungal interactions with plants and the environment is dedicated to free-floating (planktonic) cells. Fungal biofilms are generally thought to configure interactions across and among plant populations. Despite this, plant fungal biofilm research lags far behind the research on biofilms of medically important fungi. The deficit in noticing and exploring this research avenue could limit disease management and plant improvement programs. Here, we provide the current state of knowledge of fungal biofilms and the different pivotal ecological roles they impart in the context of disease, through leveraging evidence across medically important fungi, secondary metabolite production, plant beneficial functions and climate change. We also provide views on several important information gaps potentially hampering plant fungal biofilm research, and propose a way forward to address these gaps.
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Affiliation(s)
- Thabiso E Motaung
- University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Chizné Peremore
- University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Brenda Wingfield
- University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Emma Steenkamp
- University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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7
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Fournier IB, Lovejoy C, Vincent WF. Changes in the Community Structure of Under-Ice and Open-Water Microbiomes in Urban Lakes Exposed to Road Salts. Front Microbiol 2021; 12:660719. [PMID: 33868217 PMCID: PMC8044900 DOI: 10.3389/fmicb.2021.660719] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/04/2021] [Indexed: 02/01/2023] Open
Abstract
Salinization of freshwater is increasingly observed in regions where chloride de-icing salts are applied to the roads in winter, but little is known about the effects on microbial communities. In this study, we analyzed the planktonic microbiomes of four lakes that differed in degree of urbanization, eutrophication and salinization, from an oligotrophic reference lake with no surrounding roads, to a eutrophic, salinized lake receiving runoff from a highway. We tested the hypothesis that an influence of road salts would be superimposed on the effects of season and trophic status. We evaluated the microbial community structure by 16S rRNA sequencing for Bacteria, and by four methods for eukaryotes: 16S rRNA chloroplast analysis, 18S rRNA sequencing, photosynthetic pigment analysis and microscopy. Consistent with our hypothesis, chloride and total nitrogen concentrations were among the most important statistical factors explaining the differences in taxonomic composition. These factors were positively correlated with the abundance of cryptophytes, haptophytes, and cyanobacteria. Ice-cover was also a major structuring factor, with clear differences between the winter communities and those of the open-water period. Nitrifying and methane oxidizing bacteria were more abundant in winter, suggesting the importance of anaerobic sediment processes and release of reduced compounds into the ice-covered water columns. The four methods for eukaryotic analysis provided complementary information. The 18S rRNA observations were strongly influenced by the presence of ribosome-rich ciliates, but revealed a much higher degree of taxonomic richness and greater separation of lakes, seasonal changes and potential salinity effects than the other methods.
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Affiliation(s)
- Isabelle B. Fournier
- Département de Biologie and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada
- Centre for Northern Studies (CEN), Université Laval, Quebec City, QC, Canada
| | - Connie Lovejoy
- Département de Biologie and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada
- Québec-Océan, Université Laval, Quebec City, QC, Canada
| | - Warwick F. Vincent
- Département de Biologie and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada
- Centre for Northern Studies (CEN), Université Laval, Quebec City, QC, Canada
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8
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Water column gradients beneath the summer ice of a High Arctic freshwater lake as indicators of sensitivity to climate change. Sci Rep 2021; 11:2868. [PMID: 33536480 PMCID: PMC7858640 DOI: 10.1038/s41598-021-82234-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 01/12/2021] [Indexed: 11/08/2022] Open
Abstract
Ice cover persists throughout summer over many lakes at extreme polar latitudes but is likely to become increasingly rare with ongoing climate change. Here we addressed the question of how summer ice-cover affects the underlying water column of Ward Hunt Lake, a freshwater lake in the Canadian High Arctic, with attention to its vertical gradients in limnological properties that would be disrupted by ice loss. Profiling in the deepest part of the lake under thick mid-summer ice revealed a high degree of vertical structure, with gradients in temperature, conductivity and dissolved gases. Dissolved oxygen, nitrous oxide, carbon dioxide and methane rose with depth to concentrations well above air-equilibrium, with oxygen values at > 150% saturation in a mid-water column layer of potential convective mixing. Fatty acid signatures of the seston also varied with depth. Benthic microbial mats were the dominant phototrophs, growing under a dim green light regime controlled by the ice cover, water itself and weakly colored dissolved organic matter that was mostly autochthonous in origin. In this and other polar lakes, future loss of mid-summer ice will completely change many water column properties and benthic light conditions, resulting in a markedly different ecosystem regime.
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9
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Colby GA, Ruuskanen MO, St.Pierre KA, St.Louis VL, Poulain AJ, Aris-Brosou S. Warming Climate Is Reducing the Diversity of Dominant Microbes in the Largest High Arctic Lake. Front Microbiol 2020; 11:561194. [PMID: 33133035 PMCID: PMC7579425 DOI: 10.3389/fmicb.2020.561194] [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: 05/11/2020] [Accepted: 08/28/2020] [Indexed: 11/13/2022] Open
Abstract
Temperatures in the Arctic are expected to increase dramatically over the next century, and transform high latitude watersheds. However, little is known about how microbial communities and their underlying metabolic processes will be affected by these environmental changes in freshwater sedimentary systems. To address this knowledge gap, we analyzed sediments from Lake Hazen, NU Canada. Here, we exploit the spatial heterogeneity created by varying runoff regimes across the watershed of this uniquely large high-latitude lake to test how a transition from low to high runoff, used as one proxy for climate change, affects the community structure and functional potential of dominant microbes. Based on metagenomic analyses of lake sediments along these spatial gradients, we show that increasing runoff leads to a decrease in taxonomic and functional diversity of sediment microbes. Our findings are likely to apply to other, smaller, glacierized watersheds typical of polar or high latitude ecosystems; we can predict that such changes will have far reaching consequences on these ecosystems by affecting nutrient biogeochemical cycling, the direction and magnitude of which are yet to be determined.
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Affiliation(s)
- Graham A. Colby
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | | | - Kyra A. St.Pierre
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Vincent L. St.Louis
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | | | - Stéphane Aris-Brosou
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
- Department of Mathematics and Statistics, University of Ottawa, Ottawa, ON, Canada
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10
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DeSiervo MH, Ayres MP, Virginia RA, Culler LE. Consumer–resource dynamics in Arctic ponds. Ecology 2020; 101:e03135. [DOI: 10.1002/ecy.3135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 05/11/2020] [Accepted: 05/21/2020] [Indexed: 01/28/2023]
Affiliation(s)
- Melissa H. DeSiervo
- Department of Biological Sciences Dartmouth College Hanover New Hampshire03755USA
| | - Matthew P. Ayres
- Department of Biological Sciences Dartmouth College Hanover New Hampshire03755USA
- Institute of Arctic Studies The Dickey Center for International Understanding Dartmouth College Hanover New Hampshire03755USA
| | - Ross A. Virginia
- Institute of Arctic Studies The Dickey Center for International Understanding Dartmouth College Hanover New Hampshire03755USA
- Environmental Sciences Program Dartmouth College Hanover New Hampshire03755USA
| | - Lauren E. Culler
- Institute of Arctic Studies The Dickey Center for International Understanding Dartmouth College Hanover New Hampshire03755USA
- Environmental Sciences Program Dartmouth College Hanover New Hampshire03755USA
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11
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Mallick I, Kirtania P, Szabó M, Bashir F, Domonkos I, Kós PB, Vass I. A simple method to produce Synechocystis PCC6803 biofilm under laboratory conditions for electron microscopic and functional studies. PLoS One 2020; 15:e0236842. [PMID: 32730363 PMCID: PMC7392257 DOI: 10.1371/journal.pone.0236842] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/14/2020] [Indexed: 11/20/2022] Open
Abstract
Cyanobacteria can form biofilms in nature, which have ecological roles and high potential for practical applications. In order to study them we need biofilm models that contain healthy cells and can withstand physical manipulations needed for structural studies. At present, combined studies on the structural and physiological features of axenic cyanobacterial biofilms are limited, mostly due to the shortage of suitable model systems. Here, we present a simple method to establish biofilms using the cyanobacterium Synechocystis PCC6803 under standard laboratory conditions to be directly used for photosynthetic activity measurements and scanning electron microscopy (SEM). We found that glass microfiber filters (GMF) with somewhat coarse surface features provided a suitable skeleton to form Synechocystis PCC6803 biofilms. Being very fragile, untreated GMFs were unable to withstand the processing steps needed for SEM. Therefore, we used polyhydroxybutyrate coating to stabilize the filters. We found that up to five coats resulted in GMF stabilization and made possible to obtain high resolution SEM images of the structure of the surface-attached cells and the extensive exopolysaccharide and pili network, which are essential features of biofilm formation. By using pulse-amplitude modulated variable chlorophyll fluorescence imaging, it was also demonstrated that the biofilms contain photosynthetically active cells. Therefore, the Synechocystis PCC6803 biofilms formed on coated GMFs can be used for both structural and functional investigations. The model presented here is easy to replicate and has a potential for high-throughput studies.
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Affiliation(s)
- Ivy Mallick
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Prithwiraj Kirtania
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Milán Szabó
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Faiza Bashir
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
- Biology PhD School, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Ildiko Domonkos
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Peter B. Kós
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
- * E-mail:
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12
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Chrismas NAM, Williamson CJ, Yallop ML, Anesio AM, Sánchez-Baracaldo P. Photoecology of the Antarctic cyanobacterium Leptolyngbya sp. BC1307 brought to light through community analysis, comparative genomics and in vitro photophysiology. Mol Ecol 2019; 27:5279-5293. [PMID: 30565777 DOI: 10.1111/mec.14953] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 10/11/2018] [Indexed: 12/17/2022]
Abstract
Cyanobacteria are important photoautotrophs in extreme environments such as the McMurdo Dry Valleys, Antarctica. Terrestrial Antarctic cyanobacteria experience constant darkness during the winter and constant light during the summer which influences the ability of these organisms to fix carbon over the course of an annual cycle. Here, we present a unique approach combining community structure, genomic and photophysiological analyses to understand adaptation to Antarctic light regimes in the cyanobacterium Leptolyngbya sp. BC1307. We show that Leptolyngbya sp. BC1307 belongs to a clade of cyanobacteria that inhabits near-surface environments in the McMurdo Dry Valleys. Genomic analyses reveal that, unlike close relatives, Leptolyngbya sp. BC1307 lacks the genes necessary for production of the pigment phycoerythrin and is incapable of complimentary chromatic acclimation, while containing several genes responsible for known photoprotective pigments. Photophysiology experiments confirmed Leptolyngbya sp. BC1307 to be tolerant of short-term exposure to high levels of photosynthetically active radiation, while sustained exposure reduced its capacity for photoprotection. As such, Leptolyngbya sp. BC1307 likely exploits low-light microenvironments within cyanobacterial mats in the McMurdo Dry Valleys.
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Affiliation(s)
- Nathan A M Chrismas
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, UK.,School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Christopher J Williamson
- School of Geographical Sciences, University of Bristol, Bristol, UK.,School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, UK
| | - Marian L Yallop
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, UK
| | - Alexandre M Anesio
- School of Geographical Sciences, University of Bristol, Bristol, UK.,Department of Environmental Sciences, Aarhus University, Roskilde, Denmark
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13
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Vigneron A, Cruaud P, Mohit V, Martineau MJ, Culley AI, Lovejoy C, Vincent WF. Multiple Strategies for Light-Harvesting, Photoprotection, and Carbon Flow in High Latitude Microbial Mats. Front Microbiol 2018; 9:2881. [PMID: 30564204 PMCID: PMC6288179 DOI: 10.3389/fmicb.2018.02881] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/09/2018] [Indexed: 12/27/2022] Open
Abstract
Microbial mats are ubiquitous in polar freshwater ecosystems and sustain high concentrations of biomass despite the extreme seasonal variations in light and temperature. Here we aimed to resolve genomic adaptations for light-harvesting, bright-light protection, and carbon flow in mats that undergo seasonal freeze-up. To bracket a range of communities in shallow water habitats, we sampled cyanobacterial mats in the thawed littoral zone of two lakes situated at the northern and southern limits of the Canadian Arctic permafrost zone. We applied a multiphasic approach using pigment profiles from high performance liquid chromatography, Illumina MiSeq sequencing of the 16S and 18S rRNA genes, and metagenomic analysis. The mats shared a taxonomic and functional core microbiome, dominated by oxygenic cyanobacteria with light-harvesting and photoprotective pigments, bacteria with bacteriochlorophyll, and bacteria with light-driven Type I rhodopsins. Organisms able to use light for energy related processes represented up to 85% of the total microbial community, with 15–30% attributable to cyanobacteria and 55–70% attributable to other bacteria. The proportion of genes involved in anaplerotic CO2 fixation was greater than for genes associated with oxygenic photosynthesis. Diverse heterotrophic bacteria, eukaryotes (including metazoans and fungi) and viruses co-occurred in both communities. The results indicate a broad range of strategies for capturing sunlight and CO2, and for the subsequent flow of energy and carbon in these complex, light-driven microbial ecosystems.
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Affiliation(s)
- Adrien Vigneron
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Perrine Cruaud
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada.,Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, Québec, QC, Canada
| | - Vani Mohit
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Marie-Josée Martineau
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada
| | - Alexander I Culley
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada.,Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, Québec, QC, Canada
| | - Connie Lovejoy
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Warwick F Vincent
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
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14
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Tripathi VC, Satish S, Horam S, Raj S, lal A, Arockiaraj J, Pasupuleti M, Dikshit DK. Natural products from polar organisms: Structural diversity, bioactivities and potential pharmaceutical applications. POLAR SCIENCE 2018; 18:147-166. [DOI: 10.1016/j.polar.2018.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2023]
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15
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Microbial connectivity and sorting in a High Arctic watershed. ISME JOURNAL 2018; 12:2988-3000. [PMID: 30087410 DOI: 10.1038/s41396-018-0236-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 06/09/2018] [Accepted: 06/19/2018] [Indexed: 02/07/2023]
Abstract
Aquatic ecosystems in the High Arctic are facing unprecedented changes as a result of global warming effects on the cryosphere. Snow pack is a central feature of northern landscapes, but the snow microbiome and its microbial connectivity to adjacent and downstream habitats have been little explored. To evaluate these aspects, we sampled along a hydrologic continuum at Ward Hunt Lake (latitude 83°N) in the Canadian High Arctic, from snow banks, water tracks in the permafrost catchment, the upper and lower strata of the lake, and the lake outlet and its coastal marine mixing zone. The microbial communities were analyzed by high-throughput sequencing of 16 and 18S rRNA to determine the composition of potentially active Bacteria, Archaea and microbial Eukarya. Each habitat had distinct microbial assemblages, with highest species richness in the subsurface water tracks that connected the melting snow to the lake. However, up to 30% of phylotypes were shared along the hydrologic continuum, showing that many taxa originating from the snow can remain in the active fraction of downstream microbiomes. The results imply that changes in snowfall associated with climate warming will affect microbial community structure throughout all spatially connected habitats within snow-fed polar ecosystems.
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16
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Ruuskanen MO, St Pierre KA, St Louis VL, Aris-Brosou S, Poulain AJ. Physicochemical Drivers of Microbial Community Structure in Sediments of Lake Hazen, Nunavut, Canada. Front Microbiol 2018; 9:1138. [PMID: 29922252 PMCID: PMC5996194 DOI: 10.3389/fmicb.2018.01138] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 05/14/2018] [Indexed: 11/13/2022] Open
Abstract
The Arctic is undergoing rapid environmental change, potentially affecting the physicochemical constraints of microbial communities that play a large role in both carbon and nutrient cycling in lacustrine environments. However, the microbial communities in such Arctic environments have seldom been studied, and the drivers of their composition are poorly characterized. To address these gaps, we surveyed the biologically active surface sediments in Lake Hazen, the largest lake by volume north of the Arctic Circle, and a small lake and shoreline pond in its watershed. High-throughput amplicon sequencing of the 16S rRNA gene uncovered a community dominated by Proteobacteria, Bacteroidetes, and Chloroflexi, similar to those found in other cold and oligotrophic lake sediments. We also show that the microbial community structure in this Arctic polar desert is shaped by pH and redox gradients. This study lays the groundwork for predicting how sediment microbial communities in the Arctic could respond as climate change proceeds to alter their physicochemical constraints.
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Affiliation(s)
| | - Kyra A St Pierre
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Vincent L St Louis
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Stéphane Aris-Brosou
- Department of Biology, University of Ottawa, Ottawa, ON, Canada.,Department of Mathematics and Statistics, University of Ottawa, Ottawa, ON, Canada
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17
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Kleinteich J, Hildebrand F, Bahram M, Voigt AY, Wood SA, Jungblut AD, Küpper FC, Quesada A, Camacho A, Pearce DA, Convey P, Vincent WF, Zarfl C, Bork P, Dietrich DR. Pole-to-Pole Connections: Similarities between Arctic and Antarctic Microbiomes and Their Vulnerability to Environmental Change. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00137] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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