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Archibald KM, Dutkiewicz S, Laufkötter C, Moeller HV. Emergent trade-offs among plasticity strategies in mixotrophs. J Theor Biol 2024; 590:111854. [PMID: 38763324 DOI: 10.1016/j.jtbi.2024.111854] [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: 11/20/2023] [Revised: 03/14/2024] [Accepted: 05/14/2024] [Indexed: 05/21/2024]
Abstract
Marine mixotrophs combine phagotrophy and phototrophy to acquire the resources they need for growth. Metabolic plasticity, the ability for individuals to dynamically alter their relative investment between different metabolic processes, allows mixotrophs to efficiently exploit variable environmental conditions. Different mixotrophs may vary in how quickly they respond to environmental stimuli, with slow-responding mixotrophs exhibiting a significant lag between a change in the environment and the resulting change metabolic strategy. In this study, we develop a model of mixotroph metabolic strategy and explore how the rate of the plastic response affects the seasonality, competitive fitness, and biogeochemical role of mixotroph populations. Fast-responding mixotrophs are characterized by more efficient resource use and higher average growth rates than slow-responding mixotrophs because any lag in the plastic response following a change in environmental conditions creates a mismatch between the mixotroph's metabolic requirements and their resource acquisition. However, this mismatch also results in increased storage of unused resources that support growth under future nutrient-limited conditions. As a result of this trade-off, mixotroph biomass and productivity are maximized at intermediate plastic response rates. Furthermore, the trade-off represents a mechanism for coexistence between fast-responding and slow-responding mixotrophs. In mixed communities, fast-responding mixotrophs are numerically dominant, but slow-responding mixotrophs persist at low abundance due to the provisioning effect that emerges as a result of their less efficient resource acquisition strategy. In addition to increased competitive ability, fast-responding mixotrophs are, on average, more autotrophic than slow-responding mixotrophs. Notably, these trade-offs associated with mixotroph response rate arise without including an explicit physiological cost associated with plasticity, a conclusion that may provide insight into evolutionary constraints of metabolic plasticity in mixotrophic organisms. When an explicit cost is added to the model, it alters the competitive relationships between fast- and slow-responding mixotrophs. Faster plastic response rates are favored by lower physiological costs as well as higher amplitude seasonal cycles.
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Affiliation(s)
- Kevin M Archibald
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA.
| | - Stephanie Dutkiewicz
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Charlotte Laufkötter
- Climate and Environmental Physics, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA
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2
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Barbaglia GS, Paight C, Honig M, Johnson MD, Marczak R, Lepori-Bui M, Moeller HV. Environment-dependent metabolic investments in the mixotrophic chrysophyte Ochromonas. JOURNAL OF PHYCOLOGY 2024; 60:170-184. [PMID: 38141034 DOI: 10.1111/jpy.13418] [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: 07/24/2023] [Revised: 10/06/2023] [Accepted: 11/15/2023] [Indexed: 12/24/2023]
Abstract
Mixotrophic protists combine photosynthesis and phagotrophy to obtain energy and nutrients. Because mixotrophs can act as either primary producers or consumers, they have a complex role in marine food webs and biogeochemical cycles. Many mixotrophs are also phenotypically plastic and can adjust their metabolic investments in response to resource availability. Thus, a single species's ecological role may vary with environmental conditions. Here, we quantified how light and food availability impacted the growth rates, energy acquisition rates, and metabolic investment strategies of eight strains of the mixotrophic chrysophyte, Ochromonas. All eight Ochromonas strains photoacclimated by decreasing chlorophyll content as light intensity increased. Some strains were obligate phototrophs that required light for growth, while other strains showed stronger metabolic responses to prey availability. When prey availability was high, all eight strains exhibited accelerated growth rates and decreased their investments in both photosynthesis and phagotrophy. Photosynthesis and phagotrophy generally produced additive benefits: In low-prey environments, Ochromonas growth rates increased to maximum, light-saturated rates with increasing light but increased further with the addition of abundant bacterial prey. The additive benefits observed between photosynthesis and phagotrophy in Ochromonas suggest that the two metabolic modes provide nonsubstitutable resources, which may explain why a tradeoff between phagotrophic and phototrophic investments emerged in some but not all strains.
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Affiliation(s)
- Gina S Barbaglia
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, California, USA
| | - Christopher Paight
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, California, USA
| | - Meredith Honig
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, California, USA
| | - Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Ryan Marczak
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, California, USA
| | - Michelle Lepori-Bui
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, California, USA
- Washington Sea Grant, University of Washington, Seattle, Washington, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, California, USA
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3
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Charvet S, Bock NA, Kim E, Duhamel S. Transcriptomics reveal a unique phago-mixotrophic response to low nutrient concentrations in the prasinophyte Pterosperma cristatum. ISME COMMUNICATIONS 2024; 4:ycae083. [PMID: 38957873 PMCID: PMC11217555 DOI: 10.1093/ismeco/ycae083] [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: 12/15/2023] [Revised: 05/23/2024] [Accepted: 06/13/2024] [Indexed: 07/04/2024]
Abstract
Constitutive mixoplankton-plastid-bearing microbial eukaryotes capable of both phototrophy and phagotrophy-are ubiquitous in marine ecosystems and facilitate carbon transfer to higher trophic levels within aquatic food webs, which supports enhanced sinking carbon flux. However, the regulation of the relative contribution of photosynthesis and prey consumption remains poorly characterized. We investigated the transcriptional dynamics behind this phenotypic plasticity in the prasinophyte green alga Pterosperma cristatum. Based on what is known of other mixoplankton species that cannot grow without photosynthesis (obligate phototrophs), we hypothesized that P. cristatum uses phagotrophy to circumvent the restrictions imposed on photosynthesis by nutrient depletion, to obtain nutrients from ingested prey, and to maintain photosynthetic carbon fixation. We observed an increase in feeding as a response to nutrient depletion, coinciding with an upregulation of expression for genes involved in essential steps of phagocytosis including prey recognition, adhesion and engulfment, transport and maturation of food vacuoles, and digestion. Unexpectedly, genes involved in the photosynthetic electron transfer chain, pigment biosynthesis, and carbon fixation were downregulated as feeding increased, implying an abatement of photosynthesis. Contrary to our original hypothesis, our results therefore suggest that depletion of inorganic nutrients triggered an alteration of trophic behavior from photosynthesis to phagotrophy in P. cristatum. While this behavior distinguishes P. cristatum from other groups of constitutive mixoplankton, its physiological response aligns with recent discoveries from natural microbial communities. These findings indicate that mixoplankton communities in nutrient-limited oceans can regulate photosynthesis against bacterivory based on nutrient availability.
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Affiliation(s)
- Sophie Charvet
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States
- Division of Invertebrate Zoology, American Museum of Natural History, New York City, NY 10024, United States
- Department of Biology, School of Natural and Social Sciences, Susquehanna University, Selinsgrove, PA 17870, United States
| | - Nicholas A Bock
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States
- Laboratoire d’Océanographie de Villefranche, CNRS and Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Eunsoo Kim
- Division of Invertebrate Zoology, American Museum of Natural History, New York City, NY 10024, United States
- Division of EcoScience, Ewha Womans University, Seoul 03760, South Korea
| | - Solange Duhamel
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States
- Division of Invertebrate Zoology, American Museum of Natural History, New York City, NY 10024, United States
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, United States
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4
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Ma M, Yang W, Chen H, Ke W, Gong Y, Hu Q. Transcriptional profile reveals the physiological responses to prey availability in the mixotrophic chrysophyte Poterioochromonas malhamensis. Front Microbiol 2023; 14:1173541. [PMID: 37860135 PMCID: PMC10582637 DOI: 10.3389/fmicb.2023.1173541] [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: 02/24/2023] [Accepted: 09/18/2023] [Indexed: 10/21/2023] Open
Abstract
Mixotrophic flagellates, which have diverse nutritional modes and play important roles in connecting the microbial loop with the classical food chain, are ideal models to study the mechanisms of adaptation between different nutritional modes in protists. In their natural ecosystems, mixotrophic flagellates may encounter microalgal prey of different digestibility, which may affect the carbon flow. To date, a molecular biological view of the metabolic processes in the mixotrophic flagellate Poterioochromonas malhamensis during nutritional adaptation and feeding on microalgal prey of different digestibility is still lacking. Accordingly, this study focused on the gene expression differences in P. malhamensis under autotrophy, being fed by the digestible microalga Chlorella sorokiniana GT-1, and being fed by the indigestible microalga C. sorokiniana CMBB-146. Results showed that the growth rate of P. malhamensis under autotrophy was much lower than that when fed by digestible microalgae. Addition of C. sorokiniana CMBB-146 could only increase the growth rate of P. malhamensis in the first 3 days, but the cell concentration of P. malhamensis started to decrease gradually after 4 days. Compared to autotrophic P. malhamensis, total 6,583 and 3,510 genes were significantly and differentially expressed in P. malhamensis fed by digestible microalgae and indigestible microalgae, respectively. Compared to autotrophic cells, genes related to the ribosome, lysosome, glycolysis, gluconeogenesis, TCA cycle, β-oxidation, duplication, and β-1,3-glucan in P. malhamensis grazing on digestible prey were up-regulated, while genes related to light harvesting and key enzymes referring to chlorophyll were down-regulated. Genes related to apoptosis and necrosis in P. malhamensis were up-regulated after grazing on indigestible microalgae compared to the autotrophic group, which we suggest is associated with the up-regulation of genes related to lysosome enzymes. This study provides abundant information on the potential intracellular physiological responses of P. malhamensis during the process of nutritional adaptation.
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Affiliation(s)
- Mingyang Ma
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Wentao Yang
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Hong Chen
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Wanwan Ke
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Yingchun Gong
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Qiang Hu
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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5
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Millette NC, Gast RJ, Luo JY, Moeller HV, Stamieszkin K, Andersen KH, Brownlee EF, Cohen NR, Duhamel S, Dutkiewicz S, Glibert PM, Johnson MD, Leles SG, Maloney AE, Mcmanus GB, Poulton N, Princiotta SD, Sanders RW, Wilken S. Mixoplankton and mixotrophy: future research priorities. JOURNAL OF PLANKTON RESEARCH 2023; 45:576-596. [PMID: 37483910 PMCID: PMC10361813 DOI: 10.1093/plankt/fbad020] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/14/2023] [Indexed: 07/25/2023]
Abstract
Phago-mixotrophy, the combination of photoautotrophy and phagotrophy in mixoplankton, organisms that can combine both trophic strategies, have gained increasing attention over the past decade. It is now recognized that a substantial number of protistan plankton species engage in phago-mixotrophy to obtain nutrients for growth and reproduction under a range of environmental conditions. Unfortunately, our current understanding of mixoplankton in aquatic systems significantly lags behind our understanding of zooplankton and phytoplankton, limiting our ability to fully comprehend the role of mixoplankton (and phago-mixotrophy) in the plankton food web and biogeochemical cycling. Here, we put forward five research directions that we believe will lead to major advancement in the field: (i) evolution: understanding mixotrophy in the context of the evolutionary transition from phagotrophy to photoautotrophy; (ii) traits and trade-offs: identifying the key traits and trade-offs constraining mixotrophic metabolisms; (iii) biogeography: large-scale patterns of mixoplankton distribution; (iv) biogeochemistry and trophic transfer: understanding mixoplankton as conduits of nutrients and energy; and (v) in situ methods: improving the identification of in situ mixoplankton and their phago-mixotrophic activity.
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Affiliation(s)
| | - Rebecca J Gast
- Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543, USA
| | - Jessica Y Luo
- NOAA Geophysical Fluid Dynamics Laboratory, 201 Forrestal Rd., Princeton, NJ 08540, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, 1120 Noble Hall, Santa Barbara, CA 93106, USA
| | - Karen Stamieszkin
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Dr., East Boothbay, ME 04544, USA
| | - Ken H Andersen
- Center for Ocean Life, Natl. Inst. of Aquatic Resources, Technical University of Denmark, Kemitorvet, Bygning 202, Kongens Lyngby 2840, Denmark
| | - Emily F Brownlee
- Department of Biology, St. Mary’s College of Maryland, 18952 E. Fisher Road, St. Mary’s City, MD 20686, USA
| | - Natalie R Cohen
- Skidaway Institute of Oceanography, University of Georgia, 10 Ocean Science Circle, Savannah, GA 31411, USA
| | - Solange Duhamel
- Department of Molecular and Cellular Biology, The University of Arizona, 1007 E Lowell Street, Tucson, AZ 85721, USA
| | - Stephanie Dutkiewicz
- Center for Global Change Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02874, USA
| | - Patricia M Glibert
- Horn Point Laboratory, University of Maryland Center for Environmental Science, 2020 Horns Point Rd, Cambridge, MD 21613, USA
| | - Matthew D Johnson
- Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543, USA
| | - Suzana G Leles
- Department of Marine and Environmental Biology, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089, USA
| | - Ashley E Maloney
- Geosciences Department, Princeton University, Guyot Hall, Princeton, NJ 08544, USA
| | - George B Mcmanus
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Rd., Groton, CT 06340, USA
| | - Nicole Poulton
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Dr., East Boothbay, ME 04544, USA
| | - Sarah D Princiotta
- Biology Department, Pennsylvania State University, Schuylkill Campus, 200 University Drive, Schuylkill Haven, PA 17972, USA
| | - Robert W Sanders
- Department of Biology, Temple University, 1900 N. 12th St., Philadelphia, PA 19122, USA
| | - Susanne Wilken
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
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6
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Competition between phytoplankton and mixotrophs leads to metabolic character displacement. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2023.110331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
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7
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Mitra A, Flynn KJ. Low rates of bacterivory enhances phototrophy and competitive advantage for mixoplankton growing in oligotrophic waters. Sci Rep 2023; 13:6900. [PMID: 37106077 PMCID: PMC10140275 DOI: 10.1038/s41598-023-33962-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/21/2023] [Indexed: 04/29/2023] Open
Abstract
With climate change, oceans are becoming increasingly nutrient limited, favouring growth of prokaryotic picoplankton at the expense of the larger protist plankton whose growth support higher trophic levels. Constitutive mixoplankton (CM), microalgal plankton with innate phototrophic capability coupled with phagotrophy, graze on these picoplankton, indirectly exploiting the excellent resource acquisition abilities of the prokaryotes. However, feeding rates can be very low (e.g., a few bacteria d-1). For the first time, the significance of such low consumption rates has been quantified. We find that while prokaryote-carbon (C) supply to CM grown at non-limiting light was so low that it may appear insignificant (< 10%), contributions of nitrogen (N) and phosphorus (P) from ingestions of 1-12 prokaryotes d-1 were significant. Under limiting light, contributions of ingested C increased, also raising the contributions of N and P. The order of nutritional importance for CM growth from predation was P > N > C. Further, provision of N through internal recycling of ingested prey-N stimulates C-fixation through photosynthesis. Importantly, coupled photo-phago-mixoplanktonic activity improved CM resource affinities for both inorganic and prey-bound nutrients, enhancing the nutritional status and competitiveness of mixoplankton. With warming oceans, with increased prokaryote abundance, we expect CM to exhibit more phagotrophy.
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Affiliation(s)
- Aditee Mitra
- School of Earth and Environmental Sciences, Cardiff University, Park Place, Cardiff, CF10 3AT, Wales, UK.
| | - Kevin J Flynn
- Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, PL1 3DH, UK
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8
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Dorrell RG, Kuo A, Füssy Z, Richardson EH, Salamov A, Zarevski N, Freyria NJ, Ibarbalz FM, Jenkins J, Pierella Karlusich JJ, Stecca Steindorff A, Edgar RE, Handley L, Lail K, Lipzen A, Lombard V, McFarlane J, Nef C, Novák Vanclová AM, Peng Y, Plott C, Potvin M, Vieira FRJ, Barry K, de Vargas C, Henrissat B, Pelletier E, Schmutz J, Wincker P, Dacks JB, Bowler C, Grigoriev IV, Lovejoy C. Convergent evolution and horizontal gene transfer in Arctic Ocean microalgae. Life Sci Alliance 2023; 6:6/3/e202201833. [PMID: 36522135 PMCID: PMC9756366 DOI: 10.26508/lsa.202201833] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Microbial communities in the world ocean are affected strongly by oceanic circulation, creating characteristic marine biomes. The high connectivity of most of the ocean makes it difficult to disentangle selective retention of colonizing genotypes (with traits suited to biome specific conditions) from evolutionary selection, which would act on founder genotypes over time. The Arctic Ocean is exceptional with limited exchange with other oceans and ice covered since the last ice age. To test whether Arctic microalgal lineages evolved apart from algae in the global ocean, we sequenced four lineages of microalgae isolated from Arctic waters and sea ice. Here we show convergent evolution and highlight geographically limited HGT as an ecological adaptive force in the form of PFAM complements and horizontal acquisition of key adaptive genes. Notably, ice-binding proteins were acquired and horizontally transferred among Arctic strains. A comparison with Tara Oceans metagenomes and metatranscriptomes confirmed mostly Arctic distributions of these IBPs. The phylogeny of Arctic-specific genes indicated that these events were independent of bacterial-sourced HGTs in Antarctic Southern Ocean microalgae.
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Affiliation(s)
- Richard G Dorrell
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Alan Kuo
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Zoltan Füssy
- Department of Parasitology, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
| | - Elisabeth H Richardson
- Division of Infectious Diseases, Department of Medicine, University of Alberta and Department of Biological Sciences, and University of Alberta, Edmonton, Canada
| | - Asaf Salamov
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Nikola Zarevski
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Nastasia J Freyria
- Département de Biologie, Institut de Biologie Intégrative des Systèmes, Université Laval, Quebec, Canada
| | - Federico M Ibarbalz
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Jerry Jenkins
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Juan Jose Pierella Karlusich
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Andrei Stecca Steindorff
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Robyn E Edgar
- Département de Biologie, Institut de Biologie Intégrative des Systèmes, Université Laval, Quebec, Canada
| | - Lori Handley
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Kathleen Lail
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vincent Lombard
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - John McFarlane
- Division of Infectious Diseases, Department of Medicine, University of Alberta and Department of Biological Sciences, and University of Alberta, Edmonton, Canada
| | - Charlotte Nef
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Anna Mg Novák Vanclová
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Yi Peng
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Chris Plott
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Marianne Potvin
- Département de Biologie, Institut de Biologie Intégrative des Systèmes, Université Laval, Quebec, Canada
| | - Fabio Rocha Jimenez Vieira
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Kerrie Barry
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Colomban de Vargas
- CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France.,Sorbonne Université, CNRS, Station Biologique de Roscoff, AD2M, UMR 7144, Roscoff, France
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Eric Pelletier
- CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France.,Génomique Métabolique, Genoscope, Institut de Biologie François Jacob, Commissariat à l'Énergie Atomique, CNRS, Université Évry, Université Paris-Saclay, Évry, France
| | - Jeremy Schmutz
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Patrick Wincker
- CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France.,Génomique Métabolique, Genoscope, Institut de Biologie François Jacob, Commissariat à l'Énergie Atomique, CNRS, Université Évry, Université Paris-Saclay, Évry, France
| | - Joel B Dacks
- Division of Infectious Diseases, Department of Medicine, University of Alberta and Department of Biological Sciences, and University of Alberta, Edmonton, Canada
| | - Chris Bowler
- Institut de Biologie de l'ENS, Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.,CNRS Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, Paris, France
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Connie Lovejoy
- Département de Biologie, Institut de Biologie Intégrative des Systèmes, Université Laval, Quebec, Canada
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9
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Lepori‐Bui M, Paight C, Eberhard E, Mertz CM, Moeller HV. Evidence for evolutionary adaptation of mixotrophic nanoflagellates to warmer temperatures. GLOBAL CHANGE BIOLOGY 2022; 28:7094-7107. [PMID: 36107442 PMCID: PMC9828162 DOI: 10.1111/gcb.16431] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 08/19/2022] [Indexed: 05/28/2023]
Abstract
Mixotrophs, organisms that combine photosynthesis and heterotrophy to gain energy, play an important role in global biogeochemical cycles. Metabolic theory predicts that mixotrophs will become more heterotrophic with rising temperatures, potentially creating a positive feedback loop that accelerates carbon dioxide accumulation in the atmosphere. Studies testing this theory have focused on phenotypically plastic (short-term, non-evolutionary) thermal responses of mixotrophs. However, as small organisms with short generation times and large population sizes, mixotrophs may rapidly evolve in response to climate change. Here, we present data from a 3-year experiment quantifying the evolutionary response of two mixotrophic nanoflagellates to temperature. We found evidence for adaptive evolution (increased growth rates in evolved relative to acclimated lineages) in the obligately phototrophic strain, but not in the facultative phototroph. All lineages showed trends of increased carbon use efficiency, flattening of thermal reaction norms, and a return to homeostatic gene expression. Generally, mixotrophs evolved reduced photosynthesis and higher grazing with increased temperatures, suggesting that evolution may act to exacerbate mixotrophs' effects on global carbon cycling.
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Affiliation(s)
- Michelle Lepori‐Bui
- Department of Ecology, Evolution, and Marine BiologyUniversity of California – Santa BarbaraSanta BarbaraCaliforniaUSA
- Washington Sea GrantUniversity of WashingtonSeattleWashingtonUSA
| | - Christopher Paight
- Department of Ecology, Evolution, and Marine BiologyUniversity of California – Santa BarbaraSanta BarbaraCaliforniaUSA
| | - Ean Eberhard
- Department of Ecology, Evolution, and Marine BiologyUniversity of California – Santa BarbaraSanta BarbaraCaliforniaUSA
| | - Conner M. Mertz
- Department of Ecology, Evolution, and Marine BiologyUniversity of California – Santa BarbaraSanta BarbaraCaliforniaUSA
- Department of BiologyUniversity of New MexicoAlbuquerqueNew MexicoUSA
| | - Holly V. Moeller
- Department of Ecology, Evolution, and Marine BiologyUniversity of California – Santa BarbaraSanta BarbaraCaliforniaUSA
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10
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Broad phylogenetic and functional diversity among mixotrophic consumers of Prochlorococcus. THE ISME JOURNAL 2022; 16:1557-1569. [PMID: 35145244 PMCID: PMC9122939 DOI: 10.1038/s41396-022-01204-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 11/26/2022]
Abstract
Small eukaryotic phytoplankton are major contributors to global primary production and marine biogeochemical cycles. Many taxa are thought to be mixotrophic, but quantitative studies of phagotrophy exist for very few. In addition, little is known about consumers of Prochlorococcus, the abundant cyanobacterium at the base of oligotrophic ocean food webs. Here we describe thirty-nine new phytoplankton isolates from the North Pacific Subtropical Gyre (Station ALOHA), all flagellates ~2–5 µm diameter, and we quantify their ability to graze Prochlorococcus. The mixotrophs are from diverse classes (dictyochophytes, haptophytes, chrysophytes, bolidophytes, a dinoflagellate, and a chlorarachniophyte), many from previously uncultured clades. Grazing ability varied substantially, with specific clearance rate (volume cleared per body volume) varying over ten-fold across isolates and six-fold across genera. Slower grazers tended to create more biovolume per prey biovolume consumed. Using qPCR we found that the haptophyte Chrysochromulina was most abundant among the isolated mixotrophs at Station ALOHA, with 76–250 cells mL−1 across depths in the upper euphotic zone (5–100 m). Our results show that within a single ecosystem the phototrophs that ingest bacteria come from many branches of the eukaryotic tree, and are functionally diverse, indicating a broad range of strategies along the spectrum from phototrophy to phagotrophy.
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11
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García-Oliva O, Hantzsche FM, Boersma M, Wirtz KW. Phytoplankton and particle size spectra indicate intense mixotrophic dinoflagellates grazing from summer to winter. JOURNAL OF PLANKTON RESEARCH 2022; 44:224-240. [PMID: 35356359 PMCID: PMC8962713 DOI: 10.1093/plankt/fbac013] [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: 07/16/2021] [Accepted: 02/10/2021] [Indexed: 06/14/2023]
Abstract
Mixotrophic dinoflagellates (MTD) are a diverse group of organisms often responsible for the formation of harmful algal blooms. However, the development of dinoflagellate blooms and their effects on the plankton community are still not well explored. Here we relate the species succession of MTD with parallel changes of phytoplankton size spectra during periods of MTD dominance. We used FlowCAM analysis to acquire size spectra in the range 2-200 μm every one or two weeks from July to December 2007 at Helgoland Roads (Southern North Sea). Most size spectra of dinoflagellates were bimodal, whereas for other groups, e.g. diatoms and autotrophic flagellates, the spectra were unimodal, which indicates different resource use strategies of autotrophs and mixotrophs. The biomass lost in the size spectrum correlates with the potential grazing pressure of MTD. Based on size-based analysis of trophic linkages, we suggest that mixotrophy, including detritivory, drives species succession and facilitates the formation of bimodal size spectra. Bimodality in particular indicates niche differentiation through grazing of large MTD on smaller MTD. Phagotrophy of larger MTD may exceed one of the smaller MTD since larger prey was more abundant than smaller prey. Under strong light limitation, a usually overlooked refuge strategy may derive from detritivory. The critical role of trophic links of MTD as a central component of the plankton community may guide future observational and theoretical research.
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Affiliation(s)
| | - Florian M Hantzsche
- Institute of Coastal Systems - Analysis and Modeling, Helmholtz-Zentrum Hereon, Max-Planck-straße 1, Geesthacht 21502, Germany
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Biologischen Anstalt Helgoland, Helgoland 27483, Germany
| | - Maarten Boersma
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Biologischen Anstalt Helgoland, Helgoland 27483, Germany
- FB2, University of Bremen, Leobener-Straße, Bremen 28359, Germany
| | - Kai W Wirtz
- Institute of Coastal Systems - Analysis and Modeling, Helmholtz-Zentrum Hereon, Max-Planck-straße 1, Geesthacht 21502, Germany
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12
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The dynamic trophic architecture of open-ocean protist communities revealed through machine-guided metatranscriptomics. Proc Natl Acad Sci U S A 2022; 119:2100916119. [PMID: 35145022 PMCID: PMC8851463 DOI: 10.1073/pnas.2100916119] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2021] [Indexed: 12/25/2022] Open
Abstract
Mixotrophy is a ubiquitous nutritional strategy in marine ecosystems. Although our understanding of the distribution and abundance of mixotrophic plankton has improved significantly, the functional roles of mixotrophs are difficult to pinpoint, as mixotroph nutritional strategies are flexible and form a continuum between heterotrophy and phototrophy. We developed a machine learning–based method to assess the nutritional strategies of in situ planktonic populations based on metatranscriptomic profiles. We demonstrate that mixotrophic populations play varying functional roles along physicochemical gradients in the North Pacific Ocean, revealing a degree of physiological plasticity unique to aquatic mixotrophs. Our results highlight mechanisms that may dictate the flow of biogeochemical elements and ecology of the North Pacific Ocean, one of Earth's largest biogeographical provinces. Intricate networks of single-celled eukaryotes (protists) dominate carbon flow in the ocean. Their growth, demise, and interactions with other microorganisms drive the fluxes of biogeochemical elements through marine ecosystems. Mixotrophic protists are capable of both photosynthesis and ingestion of prey and are dominant components of open-ocean planktonic communities. Yet the role of mixotrophs in elemental cycling is obscured by their capacity to act as primary producers or heterotrophic consumers depending on factors that remain largely uncharacterized. Here, we develop and apply a machine learning model that predicts the in situ trophic mode of aquatic protists based on their patterns of gene expression. This approach leverages a public collection of protist transcriptomes as a training set to identify a subset of gene families whose transcriptional profiles predict trophic mode. We applied our model to nearly 100 metatranscriptomes obtained during two oceanographic cruises in the North Pacific and found community-level and population-specific evidence that abundant open-ocean mixotrophic populations shift their predominant mode of nutrient and carbon acquisition in response to natural gradients in nutrient supply and sea surface temperature. Metatranscriptomic data from ship-board incubation experiments revealed that abundant mixotrophic prymnesiophytes from the oligotrophic North Pacific subtropical gyre rapidly remodeled their transcriptome to enhance photosynthesis when supplied with limiting nutrients. Coupling this approach with experiments designed to reveal the mechanisms driving mixotroph physiology provides an avenue toward understanding the ecology of mixotrophy in the natural environment.
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13
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Potvin M, Rautio M, Lovejoy C. Freshwater Microbial Eukaryotic Core Communities, Open-Water and Under-Ice Specialists in Southern Victoria Island Lakes (Ekaluktutiak, NU, Canada). Front Microbiol 2022; 12:786094. [PMID: 35222298 PMCID: PMC8873588 DOI: 10.3389/fmicb.2021.786094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Across much of the Arctic, lakes and ponds dominate the landscape. Starting in late September, the lakes are covered in ice, with ice persisting well into June or early July. In summer, the lakes are highly productive, supporting waterfowl and fish populations. However, little is known about the diversity and ecology of microscopic life in the lakes that influence biogeochemical cycles and contribute to ecosystem services. Even less is known about the prevalence of species that are characteristic of the seasons or whether some species persist year-round under both ice cover and summer open-water conditions. To begin to address these knowledge gaps, we sampled 10 morphometrically diverse lakes in the region of Ekaluktutiak (Cambridge Bay), on southern Victoria Island (NU, Canada). We focused on Greiner Lake, the lakes connected to it, isolated ponds, and two nearby larger lakes outside the Greiner watershed. The largest lakes sampled were Tahiryuaq (Ferguson Lake) and the nearby Spawning Lake, which support commercial sea-run Arctic char (Salvelinus alpinus) fisheries. Samples for nucleic acids were collected from the lakes along with limnological metadata. Microbial eukaryotes were identified with high-throughput amplicon sequencing targeting the V4 region of the 18S rRNA gene. Ciliates, dinoflagellates, chrysophytes, and cryptophytes dominated the lake assemblages. A Bray–Curtis dissimilarity matrix separated communities into under-ice and open-water clusters, with additional separation by superficial lake area. In all, 133 operational taxonomic units (OTUs) occurred either in all under-ice or all open-water samples and were considered “core” microbial species or ecotypes. These were further characterized as seasonal indicators. Ten of the OTUs were characteristic of all lakes and all seasons sampled. Eight of these were cryptophytes, suggesting diverse functional capacity within the lineage. The core open-water indicators were mostly chrysophytes, with a few ciliates and uncharacterized Cercozoa, suggesting that summer communities are mixotrophic with contributions by heterotrophic taxa. The core under-ice indicators included a dozen ciliates along with chrysophytes, cryptomonads, and dinoflagellates, indicating a more heterotrophic community augmented by mixotrophic taxa in winter.
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Affiliation(s)
- Marianne Potvin
- Département de Biologie, Québec Océan, and Institut Intégrative et des Systèmes (IBIS), Université Laval, Quebec, QC, Canada
| | - Milla Rautio
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Saguenay, QC, Canada
- Groupe de Recherche Interuniversitaire de Limnologie (GRIL), Montreal, QC, Canada
- Center D’Études Nordiques (CEN), Quebec, QC, Canada
| | - Connie Lovejoy
- Département de Biologie, Québec Océan, and Institut Intégrative et des Systèmes (IBIS), Université Laval, Quebec, QC, Canada
- *Correspondence: Connie Lovejoy,
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14
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González-Olalla JM, Medina-Sánchez JM, Norici A, Carrillo P. Regulation of Phagotrophy by Prey, Low Nutrients, and Low Light in the Mixotrophic Haptophyte Isochrysis galbana. MICROBIAL ECOLOGY 2021; 82:981-993. [PMID: 33661311 DOI: 10.1007/s00248-021-01723-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
Mixotrophy combines autotrophy and phagotrophy in the same cell. However, it is not known to what extent the phagotrophy influences metabolism, cell composition, and growth. In this work, we assess, on the one hand (first test), the role of phagotrophy on the elemental and biochemical composition, cell metabolism, and enzymes related to C, N, and S metabolism of Isochrysis galbana Parke, 1949. On the other hand, we study how a predicted increase of phagotrophy under environmental conditions of low nutrients (second test) and low light (third test) can affect its metabolism and growth. Our results for the first test revealed that bacterivory increased the phosphorous and iron content per cell, accelerating cell division and improving the cell fitness; in addition, the stimulation of some C and N enzymatic routes help to maintain, to some degree, compositional homeostasis. Under nutrient or light scarcity, I. galbana grew more slowly despite greater bacterial consumption, and the activities of key enzymes involved in C, N, and S metabolism changed according to a predominantly phototrophic strategy of nutrition in this alga. Contrary to recent studies, the stimulation of phagotrophy under low nutrient and low irradiance did not imply greater and more efficient C flux.
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Affiliation(s)
- Juan Manuel González-Olalla
- Laboratory of Algal and Plant Physiology, Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, via Brecce Bianche, 60131, Ancona, Italy.
- University Institute of Water research, University of Granada, C/Ramón y Cajal, 4, 18071, Granada, Spain.
| | - Juan Manuel Medina-Sánchez
- University Institute of Water research, University of Granada, C/Ramón y Cajal, 4, 18071, Granada, Spain
- Department of Ecology, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, 18071, Granada, Spain
| | - Alessandra Norici
- Laboratory of Algal and Plant Physiology, Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, via Brecce Bianche, 60131, Ancona, Italy
| | - Presentación Carrillo
- University Institute of Water research, University of Granada, C/Ramón y Cajal, 4, 18071, Granada, Spain
- Department of Ecology, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, 18071, Granada, Spain
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15
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Hattenrath-Lehmann TK, Nanjappa D, Zhang H, Yu L, Goleski JA, Lin S, Gobler CJ. Transcriptomic and isotopic data reveal central role of ammonium in facilitating the growth of the mixotrophic dinoflagellate, Dinophysis acuminata. HARMFUL ALGAE 2021; 104:102031. [PMID: 34023078 DOI: 10.1016/j.hal.2021.102031] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
Dinophysis spp. are mixotrophs that are dependent on specific prey, but are also potentially reliant on dissolved nutrients. The extent to which Dinophysis relies on exogenous N and the specific biochemical pathways important for supporting its autotrophic and heterotrophic growth are unknown. Here, the nutritional ecology of Dinophysis was explored using two approaches: 1) 15N tracer experiments were conducted to quantify the concentration-dependent uptake rates and associated kinetics of various N compounds (nitrate, ammonium, urea) of Dinophysis cultures and 2) the transcriptomic responses of Dinophysis cultures grown with multiple combinations of prey and nutrients were assessed via dinoflagellate spliced leader-based transcriptome profiling. Of the N compounds examined, ammonium had the highest Vmax and affinity coefficient, and lowest Ks for both pre-starved and pre-fed cultures, collectively demonstrating the preference of Dinophysis for this N source while little-to-no nitrate uptake was observed. During the transcriptome experiments, Dinophysis grown with nitrate and without prey had the largest number of genes with lower transcript abundances, did not increase abundance of transcripts associated with nitrate/nitrite uptake or reduction, and displayed no cellular growth, suggesting D. acuminata is not capable of growing on nitrate. When offered prey, the transcriptomic response of Dinophysis included the production of phagolysosomes, enzymes involved in protein and lipid catabolism, and N acquisition through amino acid degradation pathways. Compared with cultures only offered ammonium or prey, cultures offered both ammonium and prey had the largest number of genes with increased transcript abundances, the highest growth rate, and the unique activation of multiple pathways involved in cellular catabolism, further evidencing the ability of Dinophysis to grow optimally as a mixotroph. Collectively, this study evidences the key role ammonium plays in the mixotrophic growth of Dinophysis and reveals the precise biochemical pathways that facilitate its mixotrophic growth.
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Affiliation(s)
- Theresa K Hattenrath-Lehmann
- Stony Brook University, School of Marine and Atmospheric Sciences, 239 Montauk Hwy, Southampton, NY 11968, United States
| | - Deepak Nanjappa
- Stony Brook University, School of Marine and Atmospheric Sciences, 239 Montauk Hwy, Southampton, NY 11968, United States
| | - Huan Zhang
- Department of Marine Sciences, University of Connecticut, Groton, CT 06340, United States
| | - Liying Yu
- State Key Laboratory of Marine Environmental Science and Marine Biodiversity and Global Change Research Center, Xiamen University, Xiamen 361101, China
| | - Jennifer A Goleski
- Stony Brook University, School of Marine and Atmospheric Sciences, 239 Montauk Hwy, Southampton, NY 11968, United States
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, CT 06340, United States; State Key Laboratory of Marine Environmental Science and Marine Biodiversity and Global Change Research Center, Xiamen University, Xiamen 361101, China
| | - Christopher J Gobler
- Stony Brook University, School of Marine and Atmospheric Sciences, 239 Montauk Hwy, Southampton, NY 11968, United States.
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16
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Jimenez V, Burns JA, Le Gall F, Not F, Vaulot D. No evidence of Phago-mixotropy in Micromonas polaris (Mamiellophyceae), the Dominant Picophytoplankton Species in the Arctic. JOURNAL OF PHYCOLOGY 2021; 57:435-446. [PMID: 33394518 DOI: 10.1111/jpy.13125] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 11/28/2020] [Accepted: 12/06/2020] [Indexed: 06/12/2023]
Abstract
In the Arctic Ocean, the small green alga Micromonas polaris dominates picophytoplankton during the summer months but is also present in winter. It has been previously hypothesized to be phago-mixotrophic (capable of bacteria ingestion) based on laboratory and field experiments. Prey uptake was analyzed in several M. polaris strains isolated from different regions and depths of the Arctic Ocean and in Ochromonas triangulata, a known phago-mixotroph used as a control. Measuring ingestion of either fluorescent beads or fluorescently labeled bacteria by flow cytometry, we found no evidence of phago-mixotrophy in any M. polaris strain while O. triangulata was ingesting both beads and bacteria. In addition, in silico predictions revealed that members of the genus Micromonas lack a genetic signature of phagocytotic capacity.
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Affiliation(s)
- Valeria Jimenez
- Ecology of Marine Plankton, Sorbonne Université, CNRS, UMR7144, Station Biologique de Roscoff, Roscoff, 29680, France
| | - John A Burns
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Florence Le Gall
- Ecology of Marine Plankton, Sorbonne Université, CNRS, UMR7144, Station Biologique de Roscoff, Roscoff, 29680, France
| | - Fabrice Not
- Ecology of Marine Plankton, Sorbonne Université, CNRS, UMR7144, Station Biologique de Roscoff, Roscoff, 29680, France
| | - Daniel Vaulot
- Ecology of Marine Plankton, Sorbonne Université, CNRS, UMR7144, Station Biologique de Roscoff, Roscoff, 29680, France
- Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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17
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Pujari L, Narale D, Kan J, Wu C, Zhang G, Ding C, Li L, Sun J. Distribution of Chromophytic Phytoplankton in the Eddy-Induced Upwelling Region of the West Pacific Ocean Revealed Using rbcL Genes. Front Microbiol 2021; 12:596015. [PMID: 33737916 PMCID: PMC7960667 DOI: 10.3389/fmicb.2021.596015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 01/19/2021] [Indexed: 11/17/2022] Open
Abstract
Marine chromophytic phytoplankton are a diverse group of algae and contribute significantly to the total oceanic primary production. However, the spatial distribution of chromophytic phytoplankton is understudied in the West Pacific Ocean (WPO). In this study, we have investigated the community structure and spatial distribution of chromophytic phytoplankton using RuBisCO genes (Form ID rbcL). Our results showed that Haptophyceae, Pelagophyceae, Cyanophyceae, Xanthophyceae, and Bacillariophyceae were the dominant groups. Further, chromophytic phytoplankton can be distinguished between upwelling and non-upwelling zones of the WPO. Surface and 75 m depths of a non-upwelling area were dominated by Prochlorococcus strains, whereas chromophytic phytoplankton were homogenously distributed at the surface layer in the upwelling zone. Meanwhile, Pelagomonas-like sequences were dominant at DCM (75 m) and 150 m depths of the upwelling zone. Non-metric multidimensional scaling (NMDS) analysis did not differentiate between chromophytic phytoplankton in the upwelling and non-upwelling areas, however, it showed clear trends of them at different depths. Further, redundancy analysis (RDA) showed the influence of physicochemical parameters on the distribution of chromophytic phytoplankton. Along with phosphate (p < 0.01), temperature and other dissolved nutrients were important in driving community structure. The upwelling zone was impacted by a decrease in temperature, salinity, and re-supplement of nutrients, where Pelagomonas-like sequences outnumbered other chromophytic groups presented.
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Affiliation(s)
- Laxman Pujari
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Dhiraj Narale
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Jinjun Kan
- Stroud Water Research Center, Avondale, PA, United States
| | - Chao Wu
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Guicheng Zhang
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Changling Ding
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Liuyang Li
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences, Wuhan, China
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18
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Majda S, Beisser D, Boenigk J. Nutrient-driven genome evolution revealed by comparative genomics of chrysomonad flagellates. Commun Biol 2021; 4:328. [PMID: 33712682 PMCID: PMC7954800 DOI: 10.1038/s42003-021-01781-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 01/28/2021] [Indexed: 01/31/2023] Open
Abstract
Phototrophic eukaryotes have evolved mainly by the primary or secondary uptake of photosynthetic organisms. A return to heterotrophy occurred multiple times in various protistan groups such as Chrysophyceae, despite the expected advantage of autotrophy. It is assumed that the evolutionary shift to mixotrophy and further to heterotrophy is triggered by a differential importance of nutrient and carbon limitation. We sequenced the genomes of 16 chrysophyte strains and compared them in terms of size, function, and sequence characteristics in relation to photo-, mixo- and heterotrophic nutrition. All strains were sequenced with Illumina and partly with PacBio. Heterotrophic taxa have reduced genomes and a higher GC content of up to 59% as compared to phototrophic taxa. Heterotrophs have a large pan genome, but a small core genome, indicating a differential specialization of the distinct lineages. The pan genome of mixotrophs and heterotrophs taken together but not the pan genome of the mixotrophs alone covers the complete functionality of the phototrophic strains indicating a random reduction of genes. The observed ploidy ranges from di- to tetraploidy and was found to be independent of taxonomy or trophic mode. Our results substantiate an evolution driven by nutrient and carbon limitation.
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Affiliation(s)
- Stephan Majda
- Department of Biodiversity, University of Duisburg-Essen, Essen, Germany.
| | - Daniela Beisser
- Department of Biodiversity, University of Duisburg-Essen, Essen, Germany
| | - Jens Boenigk
- Department of Biodiversity, University of Duisburg-Essen, Essen, Germany
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19
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Algae-induced taste and odour problems at low temperatures and the cold stress response hypothesis. Appl Microbiol Biotechnol 2020; 104:9079-9093. [PMID: 32965560 DOI: 10.1007/s00253-020-10884-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/03/2020] [Accepted: 08/10/2020] [Indexed: 12/17/2022]
Abstract
The existence of taste and odour (T&O) in drinking water is one of the principal causes of consumer complaints and is commonly related to algae growth. Numerous studies have confirmed the existence of algal blooms emerging specifically in low-temperature periods, herein referred to as "cold algae"; these include chrysophytes, cryptophytes, dinoflagellates and diatoms. In addition, the adaption mechanisms of these "cold algae" involve high flexibility in their nutrient intake and to the hydrological characteristics of the waters and their high contents of intracellular polyunsaturated fatty acids (PUFAs). Like algae proliferating in higher temperature waters, cold algae can also produce offensive odours. The potential dominant T&O compounds of low-temperature algae probably include saturated/unsaturated aldehydes and even some terpenoids. Among these, the polyunsaturated aldehydes (PUAs), the derivatives of polyunsaturated fatty acids, are the dominant T&O compounds and are probably synthesized during cell rupture. It was found that, for cold algae, low temperature may have a favourable effect on the generation of algae-induced T&O compounds. Furthermore, to better understand the internal mechanisms of algal T&O production, the stress response theory is introduced, which provides ideas for T&O control in raw water and in water treatment. Finally, implications for T&O management are given based on this review. KEY POINTS: • Like algae proliferating in higher temperature waters, cold algae can produce offensive odours. • Low temperatures may have a favourable effect on the generation of algae-induced T&O compounds. • The stress response theory can help to better understand the internal mechanisms of algal T&O production.
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20
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Livanou E, Barsakis K, Psarra S, Lika K. Modelling the nutritional strategies in mixotrophic nanoflagellates. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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21
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Comparative Transcriptomics Reveals Distinct Gene Expressions of a Model Ciliated Protozoa Feeding on Bacteria-Free Medium, Digestible, and Digestion-Resistant Bacteria. Microorganisms 2020; 8:microorganisms8040559. [PMID: 32295093 PMCID: PMC7232342 DOI: 10.3390/microorganisms8040559] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/07/2020] [Accepted: 04/11/2020] [Indexed: 01/03/2023] Open
Abstract
Bacterivory is an important ecological function of protists in natural ecosystems. However, there are diverse bacterial species resistant to protistan digestion, which reduces the carbon flow to higher trophic levels. So far, a molecular biological view of metabolic processes in heterotrophic protists during predation of bacterial preys of different digestibility is still lacking. In this study, we investigated the growth performance a ciliated protozoan Tetrahymenathermophila cultivated in a bacteria-free Super Proteose Peptone (SPP) medium (control), and in the media mixed with either a digestion-resistant bacterial species (DRB) or a digestible strain of E. coli (ECO). We found the protist population grew fastest in the SPP and slowest in the DRB treatment. Fluorescence in situ hybridization confirmed that there were indeed non-digested, viable bacteria in the ciliate cells fed with DRB, but none in other treatments. Comparative analysis of RNA-seq data showed that, relative to the control, 637 and 511 genes in T. thermophila were significantly and differentially expressed in the DRB and ECO treatments, respectively. The protistan expression of lysosomal proteases (especially papain-like cysteine proteinases), GH18 chitinases, and an isocitrate lyase were upregulated in both bacterial treatments. The genes encoding protease, glycosidase and involving glycolysis, TCA and glyoxylate cycles of carbon metabolic processes were higher expressed in the DRB treatment when compared with the ECO. Nevertheless, the genes for glutathione metabolism were more upregulated in the control than those in both bacterial treatments, regardless of the digestibility of the bacteria. The results of this study indicate that not only bacterial food but also digestibility of bacterial taxa modulate multiple metabolic processes in heterotrophic protists, which contribute to a better understanding of protistan bacterivory and bacteria-protists interactions on a molecular basis.
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Wilken S, Choi CJ, Worden AZ. Contrasting Mixotrophic Lifestyles Reveal Different Ecological Niches in Two Closely Related Marine Protists. JOURNAL OF PHYCOLOGY 2020; 56:52-67. [PMID: 31529498 PMCID: PMC7065223 DOI: 10.1111/jpy.12920] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/13/2019] [Indexed: 05/13/2023]
Abstract
Many marine microbial eukaryotes combine photosynthetic with phagotrophic nutrition, but incomplete understanding of such mixotrophic protists, their functional diversity, and underlying physiological mechanisms limits the assessment and modeling of their roles in present and future ocean ecosystems. We developed an experimental system to study responses of mixotrophic protists to availability of living prey and light, and used it to characterize contrasting physiological strategies in two stramenopiles in the genus Ochromonas. We show that oceanic isolate CCMP1393 is an obligate mixotroph, requiring both light and prey as complementary resources. Interdependence of photosynthesis and heterotrophy in CCMP1393 comprises a significant role of mitochondrial respiration in photosynthetic electron transport. In contrast, coastal isolate CCMP2951 is a facultative mixotroph that can substitute photosynthesis by phagotrophy and hence grow purely heterotrophically in darkness. In contrast to CCMP1393, CCMP2951 also exhibits a marked photoprotection response that integrates non-photochemical quenching and mitochondrial respiration as electron sink for photosynthetically produced reducing equivalents. Facultative mixotrophs similar to CCMP2951 might be well adapted to variable environments, while obligate mixotrophs similar to CCMP1393 appear capable of resource efficient growth in oligotrophic ocean environments. Thus, the responses of these phylogenetically close protists to the availability of different resources reveals niche differentiation that influences impacts in food webs and leads to opposing carbon cycle roles.
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Affiliation(s)
- Susanne Wilken
- Monterey Bay Aquarium Research Institute7700 Sandholdt RoadMoss LandingCalifornia95039USA
- Department of Freshwater and Marine EcologyInstitute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Chang Jae Choi
- Monterey Bay Aquarium Research Institute7700 Sandholdt RoadMoss LandingCalifornia95039USA
- Ocean EcoSystems Biology UnitGEOMAR Helmholtz Centre for Ocean ResearchDüsternbrooker Weg 20Kiel24105Germany
| | - Alexandra Z. Worden
- Monterey Bay Aquarium Research Institute7700 Sandholdt RoadMoss LandingCalifornia95039USA
- Ocean EcoSystems Biology UnitGEOMAR Helmholtz Centre for Ocean ResearchDüsternbrooker Weg 20Kiel24105Germany
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23
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Kim JI, Jeong M, Archibald JM, Shin W. Comparative Plastid Genomics of Non-Photosynthetic Chrysophytes: Genome Reduction and Compaction. FRONTIERS IN PLANT SCIENCE 2020; 11:572703. [PMID: 33013997 PMCID: PMC7511666 DOI: 10.3389/fpls.2020.572703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/24/2020] [Indexed: 05/11/2023]
Abstract
Spumella-like heterotrophic chrysophytes are important eukaryotic microorganisms that feed on bacteria in aquatic and soil environments. They are characterized by their lack of pigmentation, naked cell surface, and extremely small size. Although Spumella-like chrysophytes have lost their photosynthetic ability, they still possess a leucoplast and retain a plastid genome. We have sequenced the plastid genomes of three non-photosynthetic chrysophytes, Spumella sp. Baeckdong012018B8, Pedospumella sp. Jangsampo120217C5 and Poteriospumella lacustris Yongseonkyo072317C3, and compared them to the previously sequenced plastid genome of "Spumella" sp. NIES-1846 and photosynthetic chrysophytes. We found the plastid genomes of Spumella-like flagellates to be generally conserved with respect to genome structure and housekeeping gene content. We nevertheless also observed lineage-specific gene rearrangements and duplication of partial gene fragments at the boundary of the inverted repeat and single copy regions. Most gene losses correspond to genes for proteins involved in photosynthesis and carbon fixation, except in the case of petF. The newly sequenced plastid genomes range from ~55.7 kbp to ~62.9 kbp in size and share a core set of 45 protein-coding genes, 3 rRNAs, and 32 to 34 tRNAs. Our results provide insight into the evolutionary history of organelle genomes via genome reduction and gene loss related to loss of photosynthesis in chrysophyte evolution.
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Affiliation(s)
- Jong Im Kim
- Department of Biology, Chungnam National University, Daejeon, South Korea
| | - Minseok Jeong
- Department of Biology, Chungnam National University, Daejeon, South Korea
| | - John M. Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Woongghi Shin
- Department of Biology, Chungnam National University, Daejeon, South Korea
- *Correspondence: Woongghi Shin,
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24
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Moeller HV, Neubert MG, Johnson MD. Intraguild predation enables coexistence of competing phytoplankton in a well-mixed water column. Ecology 2019; 100:e02874. [PMID: 31463931 DOI: 10.1002/ecy.2874] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 11/10/2022]
Abstract
Resource competition theory predicts that when two species compete for a single, finite resource, the better competitor should exclude the other. However, in some cases, weaker competitors can persist through intraguild predation, that is, by eating their stronger competitor. Mixotrophs, species that meet their carbon demand by combining photosynthesis and phagotrophic heterotrophy, may function as intraguild predators when they consume the phototrophs with which they compete for light. Thus, theory predicts that mixotrophy may allow for coexistence of two species on a single limiting resource. We tested this prediction by developing a new mathematical model for a unicellular mixotroph and phytoplankter that compete for light, and comparing the model's predictions with a laboratory experimental system. We find that, like other intraguild predators, mixotrophs can persist when an ecosystem is sufficiently productive (i.e., the supply of the limiting resource, light, is relatively high), or when species interactions are strong (i.e., attack rates and conversion efficiencies are high). Both our mathematical and laboratory models show that, depending upon the environment and species traits, a variety of equilibrium outcomes, ranging from competitive exclusion to coexistence, are possible.
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Affiliation(s)
- Holly V Moeller
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA.,Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Michael G Neubert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA
| | - Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA
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25
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Beisser D, Bock C, Hahn MW, Vos M, Sures B, Rahmann S, Boenigk J. Interaction-Specific Changes in the Transcriptome of Polynucleobacter asymbioticus Caused by Varying Protistan Communities. Front Microbiol 2019; 10:1498. [PMID: 31354646 PMCID: PMC6629928 DOI: 10.3389/fmicb.2019.01498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 06/14/2019] [Indexed: 11/29/2022] Open
Abstract
We studied the impact of protist grazing and exudation on the growth and transcriptomic response of the prokaryotic prey species Polynucleobacter asymbioticus. Different single- and multi-species communities of chrysophytes were used to determine a species-specific response to the predators and the effect of chrysophyte diversity. We sequenced the mRNA of Pn. asymbioticus in communities with three single chrysophyte species (Chlorochromonas danica, Poterioochromonas malhamensis and Poteriospumella lacustris) and all combinations. The molecular responses of Pn. asymbioticus significantly changed in the presence of predators with different trophic modes and combinations of species. In the single-species samples we observed significant differences related to the relative importance of grazing and exudation in the protist-bacteria interaction, i.e., to the presence of either the heterotrophic Ps. lacustris or the mixotrophic C. danica. When grazing dominates the interaction, as in the presence of Ps. lacustris, genes acting in stress response are up-regulated. Further genes associated with transcription and translation are down-regulated indicating a reduced growth of Pn. asymbioticus. In contrast, when the potential use of algal exudates dominates the interaction, genes affiliated with iron transport are up-regulated. Rapid phototrophic growth of chrysophytes, with a high demand on soluble iron, could thus lead to iron-limitation and cause changes in the iron metabolism of Pn. asymbioticus. Additionally, we observe a benefit for Pn. asymbioticus from a more diverse protistan community, which could be due to shifts in the relative importance of phototrophy in the mixotrophic chrysophytes when competing for food with other species. Our study highlights the importance of biotic interactions and the specificity of such interactions, in particular the differential effect of grazing and algal exudation in the interaction of bacteria with mixotrophic protists.
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Affiliation(s)
| | - Christina Bock
- Biodiversity, University of Duisburg-Essen, Essen, Germany
| | - Martin W. Hahn
- Research Institute for Limnology, University of Innsbruck, Mondsee, Austria
| | - Matthijs Vos
- Theoretical and Applied Biodiversity, Ruhr-University Bochum, Bochum, Germany
| | - Bernd Sures
- Aquatic Ecology, University of Duisburg-Essen, Essen, Germany
- Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Sven Rahmann
- Genome Informatics, University of Duisburg-Essen, Essen, Germany
| | - Jens Boenigk
- Biodiversity, University of Duisburg-Essen, Essen, Germany
- Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
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26
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Principles of plastid reductive evolution illuminated by nonphotosynthetic chrysophytes. Proc Natl Acad Sci U S A 2019; 116:6914-6923. [PMID: 30872488 DOI: 10.1073/pnas.1819976116] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The division of life into producers and consumers is blurred by evolution. For example, eukaryotic phototrophs can lose the capacity to photosynthesize, although they may retain vestigial plastids that perform other essential cellular functions. Chrysophyte algae have undergone a particularly large number of photosynthesis losses. Here, we present a plastid genome sequence from a nonphotosynthetic chrysophyte, "Spumella" sp. NIES-1846, and show that it has retained a nearly identical set of plastid-encoded functions as apicomplexan parasites. Our transcriptomic analysis of 12 different photosynthetic and nonphotosynthetic chrysophyte lineages reveals remarkable convergence in the functions of these nonphotosynthetic plastids, along with informative lineage-specific retentions and losses. At one extreme, Cornospumella fuschlensis retains many photosynthesis-associated proteins, although it appears to have lost the reductive pentose phosphate pathway and most plastid amino acid metabolism pathways. At the other extreme, Paraphysomonas lacks plastid-targeted proteins associated with gene expression and all metabolic pathways that require plastid-encoded partners, indicating a complete loss of plastid DNA in this genus. Intriguingly, some of the nucleus-encoded proteins that once functioned in the expression of the Paraphysomonas plastid genome have been retained. These proteins were likely to have been dual targeted to the plastid and mitochondria of the chrysophyte ancestor, and are uniquely targeted to the mitochondria in Paraphysomonas Our comparative analyses provide insights into the process of functional reduction in nonphotosynthetic plastids.
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27
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Ma Y, Balamurugan S, Yuan W, Yang F, Tang C, Hu H, Zhang H, Shu X, Li M, Huang S, Li H, Wu L. Quercetin potentiates the concurrent hyper-accumulation of cellular biomass and lipids in Chlorella vulgaris. BIORESOURCE TECHNOLOGY 2018; 269:434-442. [PMID: 30093226 DOI: 10.1016/j.biortech.2018.07.151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 07/28/2018] [Accepted: 07/30/2018] [Indexed: 06/08/2023]
Abstract
Provision of chemical modulators has emerged as an effective strategy to govern cell growth and development. Here, the impact of flavonoid quercetin on algal growth, lipid accumulation and transcriptional patterns was investigated in the green microalga Chlorella vulgaris. These results demonstrated that quercetin (15 μg/l) significantly enhanced the cellular biomass and photosynthetic efficiency, with up to 2.5-fold in the biomass in the stationary phase. Lipidomic analyses revealed that lipid content was increased by 1.8-fold. Furthermore, the functional mechanism of quercetin on the molecular level was dissected by transcriptomic analysis. Results revealed that quercetin upregulated the expression pattern of key genes involved in cellular signaling mechanisms such as phosphatidylinositol 4-kinase α, thus consequently enhanced cell growth. Altogether, the data present in this study demonstrate the dramatic role of quercetin on enhancing microalgal biomass and lipid accumulation by unprecedented regulation, of key metabolic nodes, for the first time and provide a novel insight into microalgal metabolism and regulation.
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Affiliation(s)
- Yuhan Ma
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, Guangdong 510632, China
| | - Wasiqi Yuan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, Guangdong 510632, China
| | - Fan Yang
- School of Forestry and Landscape Architecture, Anhui Agriculture University, Hefei, Anhui 230031, China
| | - Caiguo Tang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Hao Hu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Huilan Zhang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Xian Shu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Minghao Li
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Shengwei Huang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Hongye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, Guangdong 510632, China
| | - Lifang Wu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China.
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28
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Hu SK, Liu Z, Alexander H, Campbell V, Connell PE, Dyhrman ST, Heidelberg KB, Caron DA. Shifting metabolic priorities among key protistan taxa within and below the euphotic zone. Environ Microbiol 2018; 20:2865-2879. [PMID: 29708635 DOI: 10.1111/1462-2920.14259] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/12/2022]
Abstract
A metatranscriptome study targeting the protistan community was conducted off the coast of Southern California, at the San Pedro Ocean Time-series station at the surface, 150 m (oxycline), and 890 m to link putative metabolic patterns to distinct protistan lineages. Comparison of relative transcript abundances revealed depth-related shifts in the nutritional modes of key taxonomic groups. Eukaryotic gene expression in the sunlit surface environment was dominated by phototrophs, such as diatoms and chlorophytes, and high abundances of transcripts associated with synthesis pathways (e.g., photosynthesis, carbon fixation, fatty acid synthesis). Sub-euphotic depths (150 and 890 m) exhibited strong contributions from dinoflagellates and ciliates, and were characterized by transcripts relating to digestion or intracellular nutrient recycling (e.g., breakdown of fatty acids and V-type ATPases). These transcriptional patterns underlie the distinct nutritional modes of ecologically important protistan lineages that drive marine food webs, and provide a framework to investigate trophic dynamics across diverse protistan communities.
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Affiliation(s)
- Sarah K Hu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Zhenfeng Liu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Harriet Alexander
- Department of Population Health and Reproduction, University of California Davis, Davis, CA, USA
| | - Victoria Campbell
- Division Allergy and Infectious Diseases, UW Medicine, Seattle, WA, USA
| | - Paige E Connell
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Sonya T Dyhrman
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - Karla B Heidelberg
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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