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Dong K, Wang Y, Zhang W, Li Q. Prevalence and Preferred Niche of Small Eukaryotes with Mixotrophic Potentials in the Global Ocean. Microorganisms 2024; 12:750. [PMID: 38674694 PMCID: PMC11051772 DOI: 10.3390/microorganisms12040750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/23/2024] [Accepted: 03/24/2024] [Indexed: 04/28/2024] Open
Abstract
Unicellular eukaryotes that are capable of phago-mixotrophy in the ocean compete for inorganic nutrients and light with autotrophs, and for bacterial prey with heterotrophs. In this study, we ask what the overall prevalence of eukaryotic mixotrophs in the vast open ocean is, and how the availability of inorganic nutrients, light, and prey affects their relative success. We utilized the Tara Oceans eukaryotic 18S rRNA gene and environmental context variables dataset to conduct a large-scale field analysis. We also performed isolate-based culture experiments to verify growth and nutritional resource relationships for representative mixotrophic taxa. The field analysis suggested that the overall prevalence of mixotrophs were negatively correlated with nutrient concentrations and positively associated with light availability. Concentrations of heterotrophic bacteria as a single variable also presented a positive correlation with mixotrophic prevalence, but to a lesser extent. On the other hand, the culture experiments demonstrated a taxa-specific relationship between mixotrophic growth and nutrition resources, i.e., the growth of one group was significantly dependent on light availability, while the other group was less affected by light when they received sufficient prey. Both groups were capable of growing efficiently with low inorganic nutrients when receiving sufficient prey and light. Therefore, our field analysis and culture experiments both suggest that phago-mixotrophy for ocean eukaryotes is seemingly an efficient strategy to compensate for nutrient deficiency but unnecessary to compensate for light scarcity. This study collectively revealed a close relationship between abiotic and biotic nutritional resources and the prevalence of trophic strategies, shedding light on the importance of light and nutrients for determining the competitive success of mixotrophs versus autotrophic and heterotrophic eukaryotes in the ocean.
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Affiliation(s)
- Kaiyi Dong
- School of Oceanography, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Ying Wang
- School of Oceanography, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Wenjing Zhang
- School of Oceanography, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Qian Li
- School of Oceanography, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
- Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Ministry of Education, 1954 Huashan Road, Shanghai 200030, China
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2
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Beckett SJ, Demory D, Coenen AR, Casey JR, Dugenne M, Follett CL, Connell P, Carlson MCG, Hu SK, Wilson ST, Muratore D, Rodriguez-Gonzalez RA, Peng S, Becker KW, Mende DR, Armbrust EV, Caron DA, Lindell D, White AE, Ribalet F, Weitz JS. Disentangling top-down drivers of mortality underlying diel population dynamics of Prochlorococcus in the North Pacific Subtropical Gyre. Nat Commun 2024; 15:2105. [PMID: 38453897 PMCID: PMC10920773 DOI: 10.1038/s41467-024-46165-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 02/16/2024] [Indexed: 03/09/2024] Open
Abstract
Photosynthesis fuels primary production at the base of marine food webs. Yet, in many surface ocean ecosystems, diel-driven primary production is tightly coupled to daily loss. This tight coupling raises the question: which top-down drivers predominate in maintaining persistently stable picocyanobacterial populations over longer time scales? Motivated by high-frequency surface water measurements taken in the North Pacific Subtropical Gyre (NPSG), we developed multitrophic models to investigate bottom-up and top-down mechanisms underlying the balanced control of Prochlorococcus populations. We find that incorporating photosynthetic growth with viral- and predator-induced mortality is sufficient to recapitulate daily oscillations of Prochlorococcus abundances with baseline community abundances. In doing so, we infer that grazers in this environment function as the predominant top-down factor despite high standing viral particle densities. The model-data fits also reveal the ecological relevance of light-dependent viral traits and non-canonical factors to cellular loss. Finally, we leverage sensitivity analyses to demonstrate how variation in life history traits across distinct oceanic contexts, including variation in viral adsorption and grazer clearance rates, can transform the quantitative and even qualitative importance of top-down controls in shaping Prochlorococcus population dynamics.
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Affiliation(s)
- Stephen J Beckett
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Department of Biology, University of Maryland, College Park, MD, USA.
| | - David Demory
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Sorbonne Université, CNRS, USR 3579, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Observatoire Océanologique, Banyuls-sur-Mer, France.
| | - Ashley R Coenen
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - John R Casey
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Mathilde Dugenne
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Sorbonne Université, CNRS, UMR 7093, Laboratoire d'Océanographie de Villefranche-sur-Mer (LOV), Villefranche-sur-Mer, France
| | - Christopher L Follett
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Paige Connell
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
- Biology Department, San Diego Mesa College, San Diego, CA, USA
| | - Michael C G Carlson
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
- Department of Biological Sciences, California State University, Long Beach, CA, USA
| | - Sarah K Hu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Department of Oceanography, Texas A&M University, College Station, TX, USA
| | - Samuel T Wilson
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Daniel Muratore
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Santa Fe Institute, Santa Fe, NM, USA
| | | | - Shengyun Peng
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Adobe, San Jose, CA, USA
| | - Kevin W Becker
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
| | - Daniel R Mende
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Laboratory of Applied Evolutionary Biology, Department of Medical Microbiology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | | | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Debbie Lindell
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Angelicque E White
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - François Ribalet
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Joshua S Weitz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Department of Biology, University of Maryland, College Park, MD, USA.
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA.
- Institut de Biologie, École Normale Supérieure, Paris, France.
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3
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Cai L, Li H, Deng J, Zhou R, Zeng Q. Biological interactions with Prochlorococcus: implications for the marine carbon cycle. Trends Microbiol 2024; 32:280-291. [PMID: 37722980 DOI: 10.1016/j.tim.2023.08.011] [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: 04/29/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/20/2023]
Abstract
The unicellular picocyanobacterium Prochlorococcus is the most abundant photoautotroph and contributes substantially to global CO2 fixation. In the vast euphotic zones of the open ocean, Prochlorococcus converts CO2 into organic compounds and supports diverse organisms, forming an intricate network of interactions that regulate the magnitude of carbon cycling and storage in the ocean. An understanding of the biological interactions with Prochlorococcus is critical for accurately estimating the contributions of Prochlorococcus and interacting organisms to the marine carbon cycle. This review synthesizes the primary production contributed by Prochlorococcus in the global ocean. We outline recent progress on the interactions of Prochlorococcus with heterotrophic bacteria, phages, and grazers that multifacetedly determine Prochlorococcus carbon production and fate. We discuss that climate change might affect the biological interactions with Prochlorococcus and thus the marine carbon cycle.
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Affiliation(s)
- Lanlan Cai
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
| | - Haofu Li
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen, China
| | - Junwei Deng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Ruiqian Zhou
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Qinglu Zeng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen, China; Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Hong Kong, China.
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4
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Thompson AW, Nyerges G, Brevick K, Sutherland KR. Ubiquitous filter feeders shape open ocean microbial community structure and function. PNAS NEXUS 2024; 3:pgae091. [PMID: 38505693 PMCID: PMC10949910 DOI: 10.1093/pnasnexus/pgae091] [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: 01/10/2024] [Accepted: 02/13/2024] [Indexed: 03/21/2024]
Abstract
The mechanism of mortality plays a large role in how microorganisms in the open ocean contribute to global energy and nutrient cycling. Salps are ubiquitous pelagic tunicates that are a well-known mortality source for large phototrophic microorganisms in coastal and high-latitude systems, but their impact on the immense populations of smaller prokaryotes in the tropical and subtropical open ocean gyres is not well quantified. We used robustly quantitative techniques to measure salp clearance and enrichment of specific microbial functional groups in the North Pacific Subtropical Gyre, one of the largest ecosystems on Earth. We discovered that salps are a previously unknown predator of the globally abundant nitrogen fixer Crocosphaera; thus, salps restrain new nitrogen delivery to the marine ecosystem. We show that the ocean's two numerically dominant cells, Prochlorococcus and SAR11, are not consumed by salps, which offers a new explanation for the dominance of small cells in open ocean systems. We also identified a double bonus for Prochlorococcus, wherein it not only escapes salp predation but the salps also remove one of its major mixotrophic predators, the prymnesiophyte Chrysochromulina. When we modeled the interaction between salp mesh and particles, we found that cell size alone could not account for these prey selection patterns. Instead, the results suggest that alternative mechanisms, such as surface property, shape, nutritional quality, or even prey behavior, determine which microbial cells are consumed by salps. Together, these results identify salps as a major factor in shaping the structure, function, and ecology of open ocean microbial communities.
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Affiliation(s)
- Anne W Thompson
- Department of Biology, Portland State University, Portland, OR 97201, USA
| | - Györgyi Nyerges
- Department of Biology, Pacific University, Forest Grove, OR 97116, USA
| | - Kylee Brevick
- Department of Chemistry, Portland State University, Portland, OR 97201, USA
| | - Kelly R Sutherland
- Oregon Institute of Marine Biology, University of Oregon, Eugene, OR 97403, USA
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5
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Safonov P, Berdieva M, Nassonova E, Skarlato S, Pozdnyakov I. The first arctic strain of Rhizochromulina: Morphology, ultrastructure, and position in the evolutionary tree of the order Rhizochromulinales (Heterokontophyta, Dictyochophyceae). Eur J Protistol 2024; 92:126050. [PMID: 38150922 DOI: 10.1016/j.ejop.2023.126050] [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: 09/15/2023] [Revised: 11/29/2023] [Accepted: 12/12/2023] [Indexed: 12/29/2023]
Abstract
Rhizochromulina marina is a unicellular amoeboid alga capable of forming flagellate cells; it is a single validly named species in the genus. Besides, there are numerous environmental sequences and undescribed strains designated as Rhizochromulina sp. or R. marina. The biogeography of the genus is understudied: rhizochromulines from the Indian, Southern, and Arctic Oceans are unknown. Here, we present the description of Rhizochromulina sp. B44, which was for the first time isolated from an arctic habitat. Biofilms of this microalga grow at the bottom of a culture vessel, where neighbouring amoeboid cells form associations through a common network of pseudopodia, i.e. meroplasmodia. Pseudopodia branch, anastomose mainly during meroplasmodia formation, and are supported by microtubules that arise from the perinuclear zone. Actin filaments are localized in the cytoplasm and can be revealed only near the bases of pseudopodia. We succeeded in inducing the transformation of amoeboid cells into flagellates using a prolonged agitation of cultures. Morphological and molecular analyses revealed that the studied strain is most closely related to the type strain of R. marina. At the same time, 18S rDNA sequences of early branching-off rhizochromulinids differ significantly from Rhizochromulina sp. B44, suggesting a high divergence at the genus level.
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Affiliation(s)
- Pavel Safonov
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russia.
| | - Mariia Berdieva
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russia
| | - Elena Nassonova
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russia; Saint Petersburg State University, Saint Petersburg 199034, Russia
| | - Sergei Skarlato
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russia
| | - Ilya Pozdnyakov
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russia
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6
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Kiørboe T. Predation in a Microbial World: Mechanisms and Trade-Offs of Flagellate Foraging. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:361-381. [PMID: 37368955 DOI: 10.1146/annurev-marine-020123-102001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Heterotrophic nanoflagellates are the main consumers of bacteria and picophytoplankton in the ocean and thus play a key role in ocean biogeochemistry. They are found in all major branches of the eukaryotic tree of life but are united by all being equipped with one or a few flagella that they use to generate a feeding current. These microbial predators are faced with the challenges that viscosity at this small scale impedes predator-prey contact and that their foraging activity disturbs the ambient water and thus attracts their own flow-sensing predators. Here, I describe some of the diverse adaptations of the flagellum to produce sufficient force to overcome viscosity and of the flagellar arrangement to minimize fluid disturbances, and thus of the various solutions to optimize the foraging-predation risk trade-off. I demonstrate how insights into this trade-off can be used to develop robust trait-based models of microbial food webs.
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Affiliation(s)
- Thomas Kiørboe
- Centre for Ocean Life, DTU Aqua, Technical University of Denmark, Kongens Lyngby, Denmark;
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7
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Ban H, Sato S, Yoshikawa S, Yamada K, Nakamura Y, Ichinomiya M, Sato N, Blanc-Mathieu R, Endo H, Kuwata A, Ogata H. Genome analysis of Parmales, the sister group of diatoms, reveals the evolutionary specialization of diatoms from phago-mixotrophs to photoautotrophs. Commun Biol 2023; 6:697. [PMID: 37420035 PMCID: PMC10328945 DOI: 10.1038/s42003-023-05002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 05/31/2023] [Indexed: 07/09/2023] Open
Abstract
The order Parmales (class Bolidophyceae) is a minor group of pico-sized eukaryotic marine phytoplankton that contains species with cells surrounded by silica plates. Previous studies revealed that Parmales is a member of ochrophytes and sister to diatoms (phylum Bacillariophyta), the most successful phytoplankton group in the modern ocean. Therefore, parmalean genomes can serve as a reference to elucidate both the evolutionary events that differentiated these two lineages and the genomic basis for the ecological success of diatoms vs. the more cryptic lifestyle of parmaleans. Here, we compare the genomes of eight parmaleans and five diatoms to explore their physiological and evolutionary differences. Parmaleans are predicted to be phago-mixotrophs. By contrast, diatoms have lost genes related to phagocytosis, indicating the ecological specialization from phago-mixotrophy to photoautotrophy in their early evolution. Furthermore, diatoms show significant enrichment in gene sets involved in nutrient uptake and metabolism, including iron and silica, in comparison with parmaleans. Overall, our results suggest a strong evolutionary link between the loss of phago-mixotrophy and specialization to a silicified photoautotrophic life stage early in diatom evolution after diverging from the Parmales lineage.
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Affiliation(s)
- Hiroki Ban
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Shinya Sato
- Department of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuen-cho, Obama City, Fukui, 917-0003, Japan
| | - Shinya Yoshikawa
- Department of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuen-cho, Obama City, Fukui, 917-0003, Japan
| | - Kazumasa Yamada
- Department of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuen-cho, Obama City, Fukui, 917-0003, Japan
| | - Yoji Nakamura
- Bioinformatics and Biosciences Division, Fisheries Stock Assessment Center, Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fuku-ura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Mutsuo Ichinomiya
- Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto, 862-8502, Japan
| | - Naoki Sato
- Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Romain Blanc-Mathieu
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
- Laboratoire de Physiologie Cellulaire & Végétale, CEA, Univ. Grenoble Alpes, CNRS, INRA, IRIG, Grenoble, France
| | - Hisashi Endo
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Akira Kuwata
- Shiogama field station, Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 3-27-5 Shinhama-cho, Shiogama, Miyagi, Japan.
| | - Hiroyuki Ogata
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.
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8
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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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9
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Obiol A, López-Escardó D, Salomaki ED, Wiśniewska MM, Forn I, Sà E, Vaqué D, Kolísko M, Massana R. Gene expression dynamics of natural assemblages of heterotrophic flagellates during bacterivory. MICROBIOME 2023; 11:134. [PMID: 37322519 PMCID: PMC10268365 DOI: 10.1186/s40168-023-01571-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/12/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND Marine heterotrophic flagellates (HF) are dominant bacterivores in the ocean, where they represent the trophic link between bacteria and higher trophic levels and participate in the recycling of inorganic nutrients for regenerated primary production. Studying their activity and function in the ecosystem is challenging since most of the HFs in the ocean are still uncultured. In the present work, we investigated gene expression of natural HF communities during bacterivory in four unamended seawater incubations. RESULTS The most abundant species growing in our incubations belonged to the taxonomic groups MAST-4, MAST-7, Chrysophyceae, and Telonemia. Gene expression dynamics were similar between incubations and could be divided into three states based on microbial counts, each state displaying distinct expression patterns. The analysis of samples where HF growth was highest revealed some highly expressed genes that could be related to bacterivory. Using available genomic and transcriptomic references, we identified 25 species growing in our incubations and used those to compare the expression levels of these specific genes. Video Abstract CONCLUSIONS: Our results indicate that several peptidases, together with some glycoside hydrolases and glycosyltransferases, are more expressed in phagotrophic than in phototrophic species, and thus could be used to infer the process of bacterivory in natural assemblages.
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Affiliation(s)
- Aleix Obiol
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain.
| | - David López-Escardó
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain
| | - Eric D Salomaki
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Monika M Wiśniewska
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Irene Forn
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain
| | - Elisabet Sà
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain
| | - Dolors Vaqué
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain
| | - Martin Kolísko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Ramon Massana
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain.
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10
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Edwards KF, Li Q, McBeain KA, Schvarcz CR, Steward GF. Trophic strategies explain the ocean niches of small eukaryotic phytoplankton. Proc Biol Sci 2023; 290:20222021. [PMID: 36695036 PMCID: PMC9874276 DOI: 10.1098/rspb.2022.2021] [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] [Indexed: 01/26/2023] Open
Abstract
A large fraction of marine primary production is performed by diverse small protists, and many of these phytoplankton are phagotrophic mixotrophs that vary widely in their capacity to consume bacterial prey. Prior analyses suggest that mixotrophic protists as a group vary in importance across ocean environments, but the mechanisms leading to broad functional diversity among mixotrophs, and the biogeochemical consequences of this, are less clear. Here we use isolates from seven major taxa to demonstrate a tradeoff between phototrophic performance (growth in the absence of prey) and phagotrophic performance (clearance rate when consuming Prochlorococcus). We then show that trophic strategy along the autotrophy-mixotrophy spectrum correlates strongly with global niche differences, across depths and across gradients of stratification and chlorophyll a. A model of competition shows that community shifts can be explained by greater fitness of faster-grazing mixotrophs when nutrients are scarce and light is plentiful. Our results illustrate how basic physiological constraints and principles of resource competition can organize complexity in the surface ocean ecosystem.
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Affiliation(s)
- Kyle F. Edwards
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
| | - Qian Li
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,School of Oceanography, Shanghai Jiao Tong University, 1954 Huashan Rd, Shanghai Shi, Xuhui Qu 200240, China
| | - Kelsey A. McBeain
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
| | - Christopher R. Schvarcz
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
| | - Grieg F. Steward
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
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11
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Thompson AW, Sweeney CP, Sutherland KR. Selective and differential feeding on marine prokaryotes by mucous mesh feeders. Environ Microbiol 2023; 25:880-893. [PMID: 36594240 DOI: 10.1111/1462-2920.16334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023]
Abstract
Microbial mortality impacts the structure of food webs, carbon flow, and the interactions that create dynamic patterns of abundance across gradients in space and time in diverse ecosystems. In the oceans, estimates of microbial mortality by viruses, protists, and small zooplankton do not account fully for observations of loss, suggesting the existence of underappreciated mortality sources. We examined how ubiquitous mucous mesh feeders (i.e. gelatinous zooplankton) could contribute to microbial mortality in the open ocean. We coupled capture of live animals by blue-water diving to sequence-based approaches to measure the enrichment and selectivity of feeding by two coexisting mucous grazer taxa (pteropods and salps) on numerically dominant marine prokaryotes. We show that mucous mesh grazers consume a variety of marine prokaryotes and select between coexisting lineages and similar cell sizes. We show that Prochlorococcus may evade filtration more than other cells and that planktonic archaea are consumed by macrozooplanktonic grazers. Discovery of these feeding relationships identifies a new source of mortality for Earth's dominant marine microbes and alters our understanding of how top-down processes shape microbial community and function.
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Affiliation(s)
- Anne W Thompson
- Department of Biology, Portland State University, Portland, Oregon, USA
| | - Carey P Sweeney
- Department of Biology, Portland State University, Portland, Oregon, USA
| | - Kelly R Sutherland
- Oregon Institute of Marine Biology, University of Oregon, Eugene, Oregon, USA
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