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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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Cubillos CF, Aguilar P, Moreira D, Bertolino P, Iniesto M, Dorador C, López-García P. Exploring the prokaryote-eukaryote interplay in microbial mats from an Andean athalassohaline wetland. Microbiol Spectr 2024; 12:e0007224. [PMID: 38456669 PMCID: PMC10986560 DOI: 10.1128/spectrum.00072-24] [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: 01/10/2024] [Accepted: 01/28/2024] [Indexed: 03/09/2024] Open
Abstract
Microbial community assembly results from the interaction between biotic and abiotic factors. However, environmental selection is thought to predominantly shape communities in extreme ecosystems. Salar de Huasco, situated in the high-altitude Andean Altiplano, represents a poly-extreme ecosystem displaying spatial gradients of physicochemical conditions. To disentangle the influence of abiotic and biotic factors, we studied prokaryotic and eukaryotic communities from microbial mats and underlying sediments across contrasting areas of this athalassohaline ecosystem. The prokaryotic communities were primarily composed of bacteria, notably including a significant proportion of photosynthetic organisms like Cyanobacteria and anoxygenic photosynthetic members of Alpha- and Gammaproteobacteria and Chloroflexi. Additionally, Bacteroidetes, Verrucomicrobia, and Deltaproteobacteria were abundantly represented. Among eukaryotes, photosynthetic organisms (Ochrophyta and Archaeplastida) were predominant, alongside relatively abundant ciliates, cercozoans, and flagellated fungi. Salinity emerged as a key driver for the assembly of prokaryotic communities. Collectively, abiotic factors influenced both prokaryotic and eukaryotic communities, particularly those of algae. However, prokaryotic communities strongly correlated with photosynthetic eukaryotes, suggesting a pivotal role of biotic interactions in shaping these communities. Co-occurrence networks suggested potential interactions between different organisms, such as diatoms with specific photosynthetic and heterotrophic bacteria or with protist predators, indicating influences beyond environmental selection. While some associations may be explained by environmental preferences, the robust biotic correlations, alongside insights from other ecosystems and experimental studies, suggest that symbiotic and trophic interactions significantly shape microbial mat and sediment microbial communities in this athalassohaline ecosystem.IMPORTANCEHow biotic and abiotic factors influence microbial community assembly is still poorly defined. Here, we explore their influence on prokaryotic and eukaryotic community assembly within microbial mats and sediments of an Andean high-altitude polyextreme wetland system. We show that, in addition to abiotic elements, mutual interactions exist between prokaryotic and eukaryotic communities. Notably, photosynthetic eukaryotes exhibit a strong correlation with prokaryotic communities, specifically diatoms with certain bacteria and other protists. Our findings underscore the significance of biotic interactions in community assembly and emphasize the necessity of considering the complete microbial community.
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Affiliation(s)
- Carolina F. Cubillos
- Ecologie Systématique Evolution, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pablo Aguilar
- Laboratorio de Complejidad Microbiana, Instituto Antofagasta and Centro de Bioingeniería y Biotecnología (CeBiB), Universidad de Antofagasta, Antofagasta, Chile
- Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
- Millennium Nucleus of Austral Invasive Salmonids - INVASAL, Concepción, Chile
| | - David Moreira
- Ecologie Systématique Evolution, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Paola Bertolino
- Ecologie Systématique Evolution, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Miguel Iniesto
- Ecologie Systématique Evolution, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Cristina Dorador
- Laboratorio de Complejidad Microbiana, Instituto Antofagasta and Centro de Bioingeniería y Biotecnología (CeBiB), Universidad de Antofagasta, Antofagasta, Chile
- Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
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3
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Weger HG, Polasek AK, Wright DM, Damodaran A, Stavrinides J. Grazing preferences of three species of amoebae on cyanobacteria and green algae. J Eukaryot Microbiol 2024; 71:e13018. [PMID: 38197812 DOI: 10.1111/jeu.13018] [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: 06/06/2023] [Revised: 11/25/2023] [Accepted: 12/11/2023] [Indexed: 01/11/2024]
Abstract
Twenty species/isolates of cyanobacteria and green algae were isolated from cyanobacterial bloom samples in lakes associated with the upper Qu'Appelle River drainage system in southern Saskatchewan, Canada. Three amoebae species (Cochliopodium sp., Vannella sp. and Vermamoeba vermiformis) were also isolated from one of these samples, and were subjected to grazing assays to determine which species of cyanobacteria or algae could potentially serve as a food source. Amoeba grazing rates were quantified based on the diameter of the plaque after 12 days on agar plate assays, and by estimation of the amoeba population growth rate from the rate of increase of plaque area. The common cyanobacterial bloom-formers Dolichospermum sp. and Aphanizomenon flos-aquae supported high growth rates for all three amoebae, while green algae, with the exception of one green alga/amoeba combination, did not support growth of the tested amoebae. Many of the cyanobacterial and algal isolates that did not support amoebae growth were ingested, suggesting that ingestion did not determine grazing success. Overall, while the cyanobacteria Dolichospermum sp. and Aphanizomenon flos-aquae were suitable food sources for the amoebae, the other cyanobacteria were grazed in an unpredictable manner, with some species/strains grazed by some amoebae and some species not grazed at all.
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Affiliation(s)
- Harold G Weger
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
| | - April K Polasek
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
| | - Derek M Wright
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
| | - Arun Damodaran
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
| | - John Stavrinides
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
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4
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Suthaus A, Hess S. Pseudovampyrella gen. nov.: A genus of Vampyrella-like protoplast extractors finds its place in the Leptophryidae. J Eukaryot Microbiol 2024; 71:e13002. [PMID: 37743754 DOI: 10.1111/jeu.13002] [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: 03/31/2023] [Revised: 08/09/2023] [Accepted: 09/07/2023] [Indexed: 09/26/2023]
Abstract
Vampyrellid amoebae are predatory protists, which consume a variety of eukaryotic prey and inhabit freshwater, marine and terrestrial ecosystems. Although they have been known for almost 150 years, much of their diversity lacks an in-depth characterization. To date, environmental sequencing data hint at several uncharacterized lineages, to which no phenotype is associated. Furthermore, there are numerous historically described species without any molecular information. This study reports on two new vampyrellid strains from moorlands, which extract the protoplasts of Closterium species (Zygnematophyceae). Our data on morphology, prey range specificity and feeding strategy reveal that the studied vampyrellids are very similar to the historically described Vampyrella closterii. However, phylogenetic analyses demonstrate that the two strains do not belong to the genus Vampyrella and, instead, form a distinct clade in the family Leptophryidae. Hence, we introduce a new genus of algivorous protoplast extractors, Pseudovampyrella gen. nov., with the species P. closterii (= V. closterii) and P. minor. Our findings indicate that the genetic diversity of morphologically described vampyrellid species might be hugely underrated.
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Affiliation(s)
- Andreas Suthaus
- Institute for Zoology, University of Cologne, Cologne, Germany
| | - Sebastian Hess
- Institute for Zoology, University of Cologne, Cologne, Germany
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
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5
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Jessu A, Delafont V, Moyen JL, Biet F, Samba-Louaka A, Héchard Y. Characterization of Rosculus vilicus sp. nov., a rhizarian amoeba interacting with Mycobacterium avium subsp. paratuberculosis. Front Microbiol 2023; 14:1324985. [PMID: 38188567 PMCID: PMC10770858 DOI: 10.3389/fmicb.2023.1324985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/06/2023] [Indexed: 01/09/2024] Open
Abstract
Free-living amoebae are described as potential reservoirs for pathogenic bacteria in the environment. It has been hypothesized that this might be the case for Mycobacterium avium subsp. paratuberculosis, the bacterium responsible for paratuberculosis. In a previous work, we isolated an amoeba from a water sample in the environment of infected cattle and showed that this amoeba was associated with Mycobacterium avium subsp. paratuberculosis. While a partial 18S rRNA gene has allowed us to suggest that this amoeba was Rosculus-like, at that time we were not able to sub-cultivate it. In the present study, we succeeded in cultivating this strain at 20-25°C. This amoeba is among the smallest (5-7 μm) described. The sequencing of the whole genome allowed us to extract the full 18S rRNA gene and propose this strain as a new species of the Rosculus genus, i.e., R. vilicus. Of note, the mitochondrial genome is particularly large (184,954 bp). Finally, we showed that this amoeba was able to phagocyte Mycobacterium avium subsp. paratuberculosis and that the bacterium was still observed within amoebae after at least 3 days. In conclusion, we characterized a new environmental amoeba species at the cellular and genome level that was able to interact with Mycobacterium avium subsp. paratuberculosis. As a result, R. vilicus is a potential candidate as environmental reservoir for Mycobacterium avium subsp. paratuberculosis but further experiments are needed to test this hypothesis.
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Affiliation(s)
- Amélie Jessu
- Université de Poitiers, CNRS, EBI, Poitiers, France
- Laboratoire Départemental d’Analyse et de Recherche de la Dordogne, Coulounieix-Chamiers, France
| | | | - Jean-Louis Moyen
- Laboratoire Départemental d’Analyse et de Recherche de la Dordogne, Coulounieix-Chamiers, France
| | - Franck Biet
- Laboratoire Départemental d’Analyse et de Recherche de la Dordogne, Coulounieix-Chamiers, France
| | | | - Yann Héchard
- Université de Poitiers, CNRS, EBI, Poitiers, France
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6
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Hu SK, Smith AR, Anderson RE, Sylva SP, Setzer M, Steadmon M, Frank KL, Chan EW, Lim DSS, German CR, Breier JA, Lang SQ, Butterfield DA, Fortunato CS, Seewald JS, Huber JA. Globally-distributed microbial eukaryotes exhibit endemism at deep-sea hydrothermal vents. Mol Ecol 2023; 32:6580-6598. [PMID: 36302092 DOI: 10.1111/mec.16745] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/21/2022] [Accepted: 10/06/2022] [Indexed: 11/30/2022]
Abstract
Single-celled microbial eukaryotes inhabit deep-sea hydrothermal vent environments and play critical ecological roles in the vent-associated microbial food web. 18S rRNA amplicon sequencing of diffuse venting fluids from four geographically- and geochemically-distinct hydrothermal vent fields was applied to investigate community diversity patterns among protistan assemblages. The four vent fields include Axial Seamount at the Juan de Fuca Ridge, Sea Cliff and Apollo at the Gorda Ridge, all in the NE Pacific Ocean, and Piccard and Von Damm at the Mid-Cayman Rise in the Caribbean Sea. We describe species diversity patterns with respect to hydrothermal vent field and sample type, identify putative vent endemic microbial eukaryotes, and test how vent fluid geochemistry may influence microbial community diversity. At a semi-global scale, microbial eukaryotic communities at deep-sea vents were composed of similar proportions of dinoflagellates, ciliates, Rhizaria, and stramenopiles. Individual vent fields supported distinct and highly diverse assemblages of protists that included potentially endemic or novel vent-associated strains. These findings represent a census of deep-sea hydrothermal vent protistan communities. Protistan diversity, which is shaped by the hydrothermal vent environment at a local scale, ultimately influences the vent-associated microbial food web and the broader deep-sea carbon cycle.
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Affiliation(s)
- Sarah K Hu
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Amy R Smith
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- Bard College at Simon's Rock, Great Barrington, Massachusetts, USA
| | - Rika E Anderson
- Biology Department, Carleton College, Northfield, Minnesota, USA
| | - Sean P Sylva
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Michaela Setzer
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA
- Department of Oceanography, University of Hawaii at Mānoa, Honolulu, Hawai'i, USA
| | - Maria Steadmon
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA
- Department of Oceanography, University of Hawaii at Mānoa, Honolulu, Hawai'i, USA
| | - Kiana L Frank
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA
| | - Eric W Chan
- School of Earth, Environmental, and Marine Sciences, The University of Texas Rio Grande Valley, Edinburg, Texas, USA
| | | | - Christopher R German
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - John A Breier
- School of Earth, Environmental, and Marine Sciences, The University of Texas Rio Grande Valley, Edinburg, Texas, USA
| | - Susan Q Lang
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- School of the Earth, Ocean, and Environment, University of South Carolina, Columbia, South Carolina, USA
| | - David A Butterfield
- Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington and NOAA/PMEL, Seattle, Washington, USA
| | | | - Jeffrey S Seewald
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Julie A Huber
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
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7
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Lamża Ł. Diversity of 'simple' multicellular eukaryotes: 45 independent cases and six types of multicellularity. Biol Rev Camb Philos Soc 2023; 98:2188-2209. [PMID: 37475165 DOI: 10.1111/brv.13001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/22/2023]
Abstract
Multicellularity evolved multiple times in the history of life, with most reviewers agreeing that it appeared at least 20 times in eukaryotes. However, a specific list of multicellular eukaryotes with clear criteria for inclusion has not yet been published. Herein, an updated critical review of eukaryotic multicellularity is presented, based on current understanding of eukaryotic phylogeny and new discoveries in microbiology, phycology and mycology. As a result, 45 independent multicellular lineages are identified that fall into six distinct types. Functional criteria, as distinct from a purely topological definition of a cell, are introduced to bring uniformity and clarity to the existing definitions of terms such as colony, multicellularity, thallus or plasmodium. The category of clonal multicellularity is expanded to include: (i) septated multinucleated thalli found in Pseudofungi and early-branching Fungi such as Chytridiomycota and Blastocladiomycota; and (ii) multicellular reproductive structures formed by plasmotomy in intracellular parasites such as Phytomyxea. Furthermore, (iii) endogeneous budding, as found in Paramyxida, is described as a form of multicellularity. The best-known case of clonal multicellularity, i.e. (iv) non-separation of cells after cell division, as known from Metazoa and Ochrophyta, is also discussed. The category of aggregative multicellularity is expanded to include not only (v) pseudoplasmodial forms, such a sorocarp-forming Acrasida, but also (vi) meroplasmodial organisms, such as members of Variosea or Filoreta. A common set of topological, geometric, genetic and life-cycle criteria are presented that form a coherent, philosophically sound framework for discussing multicellularity. A possibility of a seventh type of multicellularity is discussed, that of multi-species superorganisms formed by protists with obligatory bacterial symbionts, such as some members of Oxymonada or Parabasalia. Its inclusion is dependent on the philosophical stance taken towards the concepts of individuality and organism in biology. Taxa that merit special attention are identified, such as colonial Centrohelea, and a new speculative form of multicellularity, possibly present in some reticulopodial amoebae, is briefly described. Because of insufficient phylogenetic and morphological data, not all lineages could be unequivocally identified, and the true total number of all multicellular eukaryotic lineages is therefore higher, likely close to a hundred.
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Affiliation(s)
- Łukasz Lamża
- Copernicus Center for Interdisciplinary Studies, Jagiellonian University, Szczepanska 1, Kraków, 31-011, Poland
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8
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Sacharow J, Salehi-Mobarakeh E, Ratering S, Imani J, Österreicher Cunha-Dupont A, Schnell S. Control of Blumeria graminis f. sp. hordei on Barley Leaves by Treatment with Fungi-Consuming Protist Isolates. Curr Microbiol 2023; 80:384. [PMID: 37872440 PMCID: PMC10593611 DOI: 10.1007/s00284-023-03497-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 09/08/2023] [Indexed: 10/25/2023]
Abstract
The obligate biotrophic fungal pathogen Blumeria graminis causes the powdery mildew disease of cereals, which results in large crop losses. Control of B. graminis in barley is mainly achieved by fungicide treatment and by breeding resistant varieties. Vampyrellid amoebae, just like mycophagous protists, are able to consume a variety of fungi. To reveal the impact of some selected fungus-consuming protists on Blumeria graminis f. sp. hordei (Bgh), and to evaluate the possibility of using these protists as biological agents in the future, their feeding behaviour on B. graminis spores on barley leaves was investigated. An experiment was carried out with five different protist isolates (Leptophrys vorax, Platyreta germanica, Theratromyxa weberi U 11, Theratromyxa weberi G7.2 and Acanthamoeba castellanii) and four matched controls, including the food sources of the cultures and the medium. Ten-day-old leaves of barley (Hordeum vulgare cv. Golden Promise) were first inoculated with Blumeria graminis (f. sp. hordei race A6) spores, then treated with protists and fungal colonies on the leaf surfaces were counted under the microscope after 5 days. The isolates L. vorax, P. germanica, and T. weberi U11 did not show a significant reduction in the number of powdery mildew colonies whereas the isolates T. weberi G7.2 and A. castellanii significantly reduced the number of powdery mildew colonies on the leaf surfaces compared to their respective controls. This indicates that these two isolates are capable of reducing B. graminis colonies on barley leaves and are suitable candidates for further investigation for possible use as biological agents. Nevertheless, the susceptibility to dryness and the cell division rate should be considered during the optimisation of the next steps like application procedure and whole plant treatment.
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Affiliation(s)
- Julia Sacharow
- Institute of Applied Microbiology, IFZ, Justus-Liebig-University, Giessen, Germany
| | | | - Stefan Ratering
- Institute of Applied Microbiology, IFZ, Justus-Liebig-University, Giessen, Germany
| | - Jafargholi Imani
- Institute of Phytopathology, IFZ, Justus-Liebig-University, Giessen, Germany
| | | | - Sylvia Schnell
- Institute of Applied Microbiology, IFZ, Justus-Liebig-University, Giessen, Germany.
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9
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Geisen S, Lara E, Mitchell E. Contemporary issues, current best practice and ways forward in soil protist ecology. Mol Ecol Resour 2023; 23:1477-1487. [PMID: 37259890 DOI: 10.1111/1755-0998.13819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/23/2023] [Accepted: 05/17/2023] [Indexed: 06/02/2023]
Abstract
Soil protists are increasingly studied due to a release from previous methodological constraints and the acknowledgement of their immense diversity and functional importance in ecosystems. However, these studies often lack sufficient depth in knowledge, which is visible in the form of falsely used terms and false- or over-interpreted data with conclusions that cannot be drawn from the data obtained. As we welcome that also non-experts include protists in their still mostly bacterial and/or fungal-focused studies, our aim here is to help avoid some common errors. We provide suggestions for current terms to use when working on soil protists, like protist instead of protozoa, predator instead of grazer, microorganisms rather than microflora and other terms to be used to describe the prey spectrum of protists. We then highlight some dos and don'ts in soil protist ecology including challenges related to interpreting 18S rRNA gene amplicon sequencing data. We caution against the use of standard bioinformatic settings optimized for bacteria and the uncritical reliance on incomplete and partly erroneous reference databases. We also show why causal inferences cannot be drawn from sequence-based correlation analyses or any sampling/monitoring, study in the field without thorough experimental confirmation and sound understanding of the biology of taxa. Together, we envision this work to help non-experts to more easily include protists in their soil ecology analyses and obtain more reliable interpretations from their protist data and other biodiversity data that, in the end, will contribute to a better understanding of soil ecology.
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Affiliation(s)
- Stefan Geisen
- Laboratory of Nematology, Wageningen University, Wageningen, The Netherlands
| | | | - Edward Mitchell
- Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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10
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Michoud G, Kohler TJ, Ezzat L, Peter H, Nattabi JK, Nalwanga R, Pramateftaki P, Styllas M, Tolosano M, De Staercke V, Schön M, Marasco R, Daffonchio D, Bourquin M, Busi SB, Battin TJ. The dark side of the moon: first insights into the microbiome structure and function of one of the last glacier-fed streams in Africa. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230329. [PMID: 37564072 PMCID: PMC10410210 DOI: 10.1098/rsos.230329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/20/2023] [Indexed: 08/12/2023]
Abstract
The glaciers on Africa's 'Mountains of the Moon' (Rwenzori National Park, Uganda) are predicted to disappear within the next decades owing to climate change. Consequently, the glacier-fed streams (GFSs) that drain them will vanish, along with their resident microbial communities. Despite the relevance of microbial communities for performing ecosystem processes in equatorial GFSs, their ecology remains understudied. Here, we show that the benthic microbiome from the Mt. Stanley GFS is distinct at several levels from other GFSs. Specifically, several novel taxa were present, and usually common groups such as Chrysophytes and Polaromonas exhibited lower relative abundances compared to higher-latitude GFSs, while cyanobacteria and diatoms were more abundant. The rich primary producer community in this GFS likely results from the greater environmental stability of the Afrotropics, and accordingly, heterotrophic processes dominated in the bacterial community. Metagenomics revealed that almost all prokaryotes in the Mt. Stanley GFS are capable of organic carbon oxidation, while greater than 80% have the potential for fermentation and acetate oxidation. Our findings suggest a close coupling between photoautotrophs and other microbes in this GFS, and provide a glimpse into the future for high-latitude GFSs globally where primary production is projected to increase with ongoing glacier shrinkage.
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Affiliation(s)
- Grégoire Michoud
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Tyler J. Kohler
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Leïla Ezzat
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Hannes Peter
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Juliet Kigongo Nattabi
- Department of Zoology, Entomology and Fisheries Sciences (ZEFs), College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Rosemary Nalwanga
- Department of Zoology, Entomology and Fisheries Sciences (ZEFs), College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Paraskevi Pramateftaki
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Michail Styllas
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Matteo Tolosano
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Vincent De Staercke
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Martina Schön
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ramona Marasco
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Daniele Daffonchio
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Massimo Bourquin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Susheel Bhanu Busi
- Systems Ecology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Tom J. Battin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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Garvetto A, Murúa P, Kirchmair M, Salvenmoser W, Hittorf M, Ciaghi S, Harikrishnan SL, Gachon CMM, Burns JA, Neuhauser S. Phagocytosis underpins the biotrophic lifestyle of intracellular parasites in the class Phytomyxea (Rhizaria). THE NEW PHYTOLOGIST 2023; 238:2130-2143. [PMID: 36810975 PMCID: PMC10953367 DOI: 10.1111/nph.18828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/06/2023] [Indexed: 05/04/2023]
Abstract
Phytomyxea are intracellular biotrophic parasites infecting plants and stramenopiles, including the agriculturally impactful Plasmodiophora brassicae and the brown seaweed pathogen Maullinia ectocarpii. They belong to the clade Rhizaria, where phagotrophy is the main mode of nutrition. Phagocytosis is a complex trait of eukaryotes, well documented for free-living unicellular eukaryotes and specific cellular types of animals. Data on phagocytosis in intracellular, biotrophic parasites are scant. Phagocytosis, where parts of the host cell are consumed at once, is seemingly at odds with intracellular biotrophy. Here we provide evidence that phagotrophy is part of the nutritional strategy of Phytomyxea, using morphological and genetic data (including a novel transcriptome of M. ectocarpii). We document intracellular phagocytosis in P. brassicae and M. ectocarpii by transmission electron microscopy and fluorescent in situ hybridization. Our investigations confirm molecular signatures of phagocytosis in Phytomyxea and hint at a small specialized subset of genes used for intracellular phagocytosis. Microscopic evidence confirms the existence of intracellular phagocytosis, which in Phytomyxea targets primarily host organelles. Phagocytosis seems to coexist with the manipulation of host physiology typical of biotrophic interactions. Our findings resolve long debated questions on the feeding behaviour of Phytomyxea, suggesting an unrecognized role for phagocytosis in biotrophic interactions.
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Affiliation(s)
- Andrea Garvetto
- Institute of MicrobiologyUniversity of InnsbruckTechnikerstraße 25Innsbruck6020TyrolAustria
| | - Pedro Murúa
- Laboratorio de Macroalgas, Instituto de AcuiculturaUniversidad Austral de ChilePuerto Montt5480000Chile
| | - Martin Kirchmair
- Institute of MicrobiologyUniversity of InnsbruckTechnikerstraße 25Innsbruck6020TyrolAustria
| | - Willibald Salvenmoser
- Institute of ZoologyUniversity of InnsbruckTechnikerstraße 25Innsbruck6020TyrolAustria
| | - Michaela Hittorf
- Institute of MicrobiologyUniversity of InnsbruckTechnikerstraße 25Innsbruck6020TyrolAustria
| | - Stefan Ciaghi
- Institute of MicrobiologyUniversity of InnsbruckTechnikerstraße 25Innsbruck6020TyrolAustria
| | - Srilakshmy L. Harikrishnan
- Centre for Plant Systems BiologyVIBZwijnaarde 71Ghent9052Belgium
- Department of Plant Biotechnology and BioinformaticsGhent UniversityZwijnaarde 71Ghent9052Belgium
| | - Claire M. M. Gachon
- Muséum National d'Histoire Naturelle, UMR 7245, CNRS CP 2657 rue Cuvier75005ParisFrance
- Scottish Association for Marine ScienceScottish Marine InstituteDunbegObanPA37 1QAUK
| | - John A. Burns
- Bigelow Laboratory for Ocean Sciences60 Bigelow Dr.East BoothbayME04544USA
| | - Sigrid Neuhauser
- Institute of MicrobiologyUniversity of InnsbruckTechnikerstraße 25Innsbruck6020TyrolAustria
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12
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Moye J, Schenk T, Hess S. Experimental evidence for enzymatic cell wall dissolution in a microbial protoplast feeder (Orciraptor agilis, Viridiraptoridae). BMC Biol 2022; 20:267. [PMID: 36464670 PMCID: PMC9721047 DOI: 10.1186/s12915-022-01478-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/24/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Several protists have evolved the ability to perforate the cell walls of algae and fungi to specifically feed on their cell contents. These phagotrophic "protoplast feeders" represent an interesting mechanistic intermediate between predators and parasites and pose a number of cell biological questions. Although their fascinating feeding behaviour has been observed for the last 150 years, it is still unknown how protoplast feeders produce the well-defined and species-specific perforations in biochemically diverse cell walls. Differential expression analyses of the algivorous flagellate Orciraptor agilis (Viridiraptoridae, Cercozoa, Rhizaria) suggested the involvement of a highly expressed putative glycoside hydrolase of family GH5_5. To assess the importance of this carbohydrate-active enzyme in the feeding act of Orciraptor, we recombinantly produced its catalytic domain and studied the enzymatic activity, cellular localisation and function. RESULTS The GH5_5 catalytic domain from Orciraptor showed pronounced activity on soluble cellulose derivatives and mixed-linkage glucans, with reaction optima comparable to known GH5_5 representatives. Crystalline cellulose was not digested by the enzyme, which suggests a typical endocellulase activity. Immunocytochemistry with a polyclonal antibody raised against the GH5_5 domain revealed that the native endocellulase localises to the contact zone of Orciraptor and the algal cell wall (= perforation zone) and to intracellular granules, which were enriched during attack. Furthermore, the anti-GH5_5 antibody applied to live cells significantly reduced the feeding success of Orciraptor. The cells attacked the algae, which, however, resulted in numerous incomplete perforations. CONCLUSIONS Our experimental data from enzymatic assays, immunocytochemistry and inhibition experiments strongly suggest a key role of the GH5_5 endocellulase in cell wall dissolution by Orciraptor agilis. With that, we provide evidence that the well-defined perforations produced by protoplast feeders are caused by extracellular carbohydrate-active enzymes and made a first step towards establishing the molecular basis of a fascinating, yet poorly understood microbial feeding strategy.
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Affiliation(s)
- Jannika Moye
- grid.6190.e0000 0000 8580 3777Institute for Zoology, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Tobias Schenk
- grid.6190.e0000 0000 8580 3777Institute for Zoology, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Sebastian Hess
- grid.6190.e0000 0000 8580 3777Institute for Zoology, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
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Kinopus chlorellivorus
gen. nov., sp. nov. (Vampyrellida, Rhizaria), a New Algivorous Protist Predator Isolated from Large-Scale Outdoor Cultures of
Chlorella sorokiniana. Appl Environ Microbiol 2022; 88:e0121522. [PMID: 36300943 PMCID: PMC9680614 DOI: 10.1128/aem.01215-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The vampyrellids (Vampyrellida, Rhizaria) are a major group of predatory amoebae that have attracted significant attention because of their diversity of feeding strategies. The crucial roles they play in important processes such as suppressing soil disease and controlling aquatic algae, and as microbial contaminants in outdoor large-scale algal cultures, have also received increasing attention.
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Gabaldón T, Völcker E, Torruella G. On the Biology, Diversity and Evolution of Nucleariid Amoebae (Amorphea, Obazoa, Opisthokonta. Protist 2022; 173:125895. [DOI: 10.1016/j.protis.2022.125895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 10/18/2022]
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