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Duerschlag J, Mohr W, Ferdelman TG, LaRoche J, Desai D, Croot PL, Voß D, Zielinski O, Lavik G, Littmann S, Martínez-Pérez C, Tschitschko B, Bartlau N, Osterholz H, Dittmar T, Kuypers MMM. Niche partitioning by photosynthetic plankton as a driver of CO 2-fixation across the oligotrophic South Pacific Subtropical Ocean. ISME JOURNAL 2021; 16:465-476. [PMID: 34413475 PMCID: PMC8776750 DOI: 10.1038/s41396-021-01072-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/08/2021] [Accepted: 07/16/2021] [Indexed: 11/09/2022]
Abstract
Oligotrophic ocean gyre ecosystems may be expanding due to rising global temperatures [1-5]. Models predicting carbon flow through these changing ecosystems require accurate descriptions of phytoplankton communities and their metabolic activities [6]. We therefore measured distributions and activities of cyanobacteria and small photosynthetic eukaryotes throughout the euphotic zone on a zonal transect through the South Pacific Ocean, focusing on the ultraoligotrophic waters of the South Pacific Gyre (SPG). Bulk rates of CO2 fixation were low (0.1 µmol C l-1 d-1) but pervasive throughout both the surface mixed-layer (upper 150 m), as well as the deep chlorophyll a maximum of the core SPG. Chloroplast 16S rRNA metabarcoding, and single-cell 13CO2 uptake experiments demonstrated niche differentiation among the small eukaryotes and picocyanobacteria. Prochlorococcus abundances, activity, and growth were more closely associated with the rims of the gyre. Small, fast-growing, photosynthetic eukaryotes, likely related to the Pelagophyceae, characterized the deep chlorophyll a maximum. In contrast, a slower growing population of photosynthetic eukaryotes, likely comprised of Dictyochophyceae and Chrysophyceae, dominated the mixed layer that contributed 65-88% of the areal CO2 fixation within the core SPG. Small photosynthetic eukaryotes may thus play an underappreciated role in CO2 fixation in the surface mixed-layer waters of ultraoligotrophic ecosystems.
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Affiliation(s)
- Julia Duerschlag
- Max Planck Institute for Marine Microbiology, Bremen, Germany.,Department of Geophysical Sciences, University of Chicago, Chicago, IL, USA
| | - Wiebke Mohr
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | | | - Julie LaRoche
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Dhwani Desai
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Peter L Croot
- iCRAG (Irish Centre for Research in Applied Geoscience), Earth and Ocean Sciences, School of Natural Sciences and the Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Daniela Voß
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Oliver Zielinski
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany.,Marine Perception Research Group, German Research Center for Artificial Intelligence (DFKI), Oldenburg, Germany
| | - Gaute Lavik
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Sten Littmann
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Clara Martínez-Pérez
- Max Planck Institute for Marine Microbiology, Bremen, Germany.,Institute for Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, Zurich, Switzerland
| | | | - Nina Bartlau
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Helena Osterholz
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany.,Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
| | - Thorsten Dittmar
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany.,Helmholtz Institute for Functional Marine Biodiversity (HIFMB), University of Oldenburg, Oldenburg, Germany
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Pitt FD, Millard A, Ostrowski M, Dervish S, Mazard S, Paulsen IT, Zubkov MV, Scanlan DJ. A Sample-to-Sequence Protocol for Genus Targeted Transcriptomic Profiling: Application to Marine Synechococcus. Front Microbiol 2016; 7:1592. [PMID: 27790194 PMCID: PMC5063861 DOI: 10.3389/fmicb.2016.01592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 09/22/2016] [Indexed: 12/02/2022] Open
Abstract
Recent studies using whole community metagenomic and metatranscriptomic approaches are revealing important new insights into the functional potential and activity of natural marine microbial communities. Here, we complement these approaches by describing a complete ocean sample-to-sequence protocol, specifically designed to target a single bacterial genus for purposes of both DNA and RNA profiling using fluorescence activated cell sorting (FACS). The importance of defining and understanding the effects of a sampling protocol are critical if we are to gain meaningful data from environmental surveys. Rigorous pipeline trials with a cultured isolate, Synechococcus sp. BL107 demonstrate that water filtration has a well-defined but limited impact on the transcriptomic profile of this organism, whilst sample storage and multiple rounds of cell sorting have almost no effect on the resulting RNA sequence profile. Attractively, the means to replicate the sampling strategy is within the budget and expertise of most researchers.
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Affiliation(s)
- Frances D Pitt
- School of Life Sciences, University of Warwick Coventry, UK
| | - Andrew Millard
- Warwick Medical School, University of Warwick Coventry, UK
| | - Martin Ostrowski
- Department of Biochemistry and Biomolecular Science, Faculty of Science and Engineering, Macquarie University Sydney, NSW, Australia
| | - Suat Dervish
- Sydney Cytometry, Centenary Institute, University of Sydney Sydney, NSW, Australia
| | - Sophie Mazard
- Department of Biochemistry and Biomolecular Science, Faculty of Science and Engineering, Macquarie University Sydney, NSW, Australia
| | - Ian T Paulsen
- Department of Biochemistry and Biomolecular Science, Faculty of Science and Engineering, Macquarie University Sydney, NSW, Australia
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Lepère C, Ostrowski M, Hartmann M, Zubkov MV, Scanlan DJ. In situ associations between marine photosynthetic picoeukaryotes and potential parasites - a role for fungi? ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:445-51. [PMID: 26420747 DOI: 10.1111/1758-2229.12339] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 05/25/2023]
Abstract
Photosynthetic picoeukaryotes (PPEs) are important components of the marine picophytoplankton community playing a critical role in CO2 fixation but also as bacterivores, particularly in the oligotrophic gyres. Despite an increased interest in these organisms and an improved understanding of the genetic diversity of this group, we still know little of the environmental factors controlling the abundance of these organisms. Here, we investigated the quantitative importance of eukaryotic parasites in the free-living fraction as well as in associations with PPEs along a transect in the South Atlantic. Using tyramide signal amplification-fluorescence in situ hybridization (TSA-FISH), we provide quantitative evidence of the occurrence of free-living fungi in open ocean marine systems, while the Perkinsozoa and Syndiniales parasites were not abundant in these waters. Using flow cytometric cell sorting of different PPE populations followed by a dual-labelled TSA-FISH approach, we also demonstrate fungal associations, potentially parasitic, occurring with both pico-Prymnesiophyceae and pico-Chrysophyceae. These data highlight the necessity for further work investigating the specific role of marine fungi as parasites of phytoplankton to improve understanding of carbon flow in marine ecosystems.
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Affiliation(s)
- Cécile Lepère
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
- Université Clermont Auvergne, Université Blaise Pascal, Laboratoire 'Microorganismes : Génome et Environnement', BP 10448, Clermont-Ferrand, F-63000, France
- CNRS, UMR 6023, LMGE, Aubière, F-63171, France
| | - Martin Ostrowski
- Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | | | | | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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