Blar i Faculty of Mathematics and Natural Sciences på forfatter "Bratbak, Gunnar"

Viser treff 1-20 av 25

    • The 474-Kilobase-Pair Complete Genome Sequence of CeV-01B, a Virus Infecting Haptolina (Chrysochromulina) ericina(Prymnesiophyceae) 

      Gallot-lavallée, Lucie; Pagarete, António; Legendre, Matthieu; Santini, Sebastien; Sandaa, Ruth-Anne; Himmelbauer, Heinz; Ogata, Hiroyuki; Bratbak, Gunnar; Claverie, Jean-Michel (Peer reviewed; Journal article, 2015-12-03)
      We report the complete genome sequence of CeV-01B, a large double-stranded DNA virus infecting the unicellular marine phytoplankton Haptolina (formerly Chrysochromulina) ericina. CeV-01B and its closest relative Phaeocystis ...

    • Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study 

      Tsagaraki, Tatiana Margo; Pree, Bernadette; Leiknes, Øystein; Larsen, Aud; Bratbak, Gunnar; Øvreås, Lise; Egge, Jorun Karin; Spanek, Roman; Paulsen, Maria Lund; Olsen, Yngvar; Vadstein, Olav; Thingstad, T. Frede (Peer reviewed; Journal article, 2018)
      Combining a minimum food web model with Arctic microbial community dynamics, we have suggested that top-down control by copepods can affect the food web down to bacterial consumption of organic carbon. Pursuing this ...

    • Bacterial Response to Permafrost Derived Organic Matter Input in an Arctic Fjord 

      Müller, Oliver; Seuthe, Lena; Bratbak, Gunnar; Paulsen, Maria Lund (Peer reviewed; Journal article, 2018-08-06)
      The warming of the Arctic causes increased riverine discharge, coastal erosion, and the thawing of permafrost. Together, this is leading to an increased wash out of terrestrial dissolved organic matter (tDOM) into the ...

    • Bioorthogonal Non-canonical Amino Acid Tagging Combined With Flow Cytometry for Determination of Activity in Aquatic Microorganisms 

      Lindivat, Mathilde; Larsen, Aud; Hess-Erga, Ole-Kristian; Bratbak, Gunnar; Hoell, Ingunn (Journal article; Peer reviewed, 2020)
      In this study, we have combined bioorthogonal non-canonical amino acid tagging (BONCAT) and flow cytometry (FCM) analysis, and we demonstrate the applicability of the method for marine prokaryotes. Enumeration of active ...

    • Changes in marine prokaryote composition with season and depth over an Arctic polar year 

      Wilson, Bryan; Müller, Oliver; Nordmann, Eva-Lena; Seuthe, Lena; Bratbak, Gunnar; Øvreås, Lise (Peer reviewed; Journal article, 2017-04-13)
      As the global climate changes, the higher latitudes are seen to be warming significantly faster. It is likely that the Arctic biome will experience considerable shifts in ice melt season length, leading to changes in ...

    • Contrasting response to nutrient manipulation in Arctic mesocosms are reproduced by a minimum microbial food web model 

      Larsen, Aud; Egge, Jorun Karin; Nejstgaard, Jens Christian; Di Capua, Iole; Thyrhaug, Runar; Bratbak, Gunnar; Thingstad, Tron Frede (Peer reviewed; Journal article, 2015-01-27)
      A minimum mathematical model of the marine pelagic microbial food web has previously shown to be able to reproduce central aspects of observed system response to different bottom-up manipulations in a mesocosm experiment ...

    • Differential toxicity of bioorthogonal non-canonical amino acids (BONCAT) in Escherichia coli 

      Landor, Lotta Anni Ingeborg; Bratbak, Gunnar; Larsen, Aud; Tjendra, Jesslyn; Våge, Selina (Journal article; Peer reviewed, 2023)
      Single-cell methods allow studying the activity of single bacterial cells, potentially shedding light on regulatory mechanisms involved in services like biochemical cycling. Bioorthogonal non-canonical amino acid tagging ...

    • Earlier sea-ice melt extends the oligotrophic summer period in the Barents Sea with low algal biomass and associated low vertical flux 

      Kohlbach, Doreen; Goraguer, Lucie; Bodur, Yasemin V.; Müller, Oliver; Amargant Arumí, Martí; Blix, Katalin; Bratbak, Gunnar; Chierici, Melissa; Dabrowska, Anna Maria; Dietrich, Ulrike; Edvardsen, Bente; Garcia, Laura; Gradinger, Rolf Rudolf; Hop, Haakon; Jones, Elizabeth Marie; Øyvind, Lundesgaard; Olsen, Lasse Mork; Reigstad, Marit; Saubrekka, Karoline; Tatarek, Agnieszka; Wiktor, Josef Maria; Wold, Anette; Assmy, Philipp (Journal article; Peer reviewed, 2023)
      The decrease in Arctic sea-ice extent and thickness as a result of global warming will impact the timing, duration, magnitude and composition of phytoplankton production with cascading effects on Arctic marine food-webs ...

    • First phytoplankton community assessment of the Kong Håkon VII Hav, Southern Ocean, during austral autumn 

      Kauko, Hanna Maria; Assmy, Philipp; Peeken, Ilka; Rózańska-Pluta, Magdalena; Wiktor, Józef M; Bratbak, Gunnar; Singh, Asmita; Ryan-Keogh, Thomas J.; Moreau, Sebastien (Journal article; Peer reviewed, 2022)
      We studied phytoplankton and protozooplankton community composition based on light microscopy, flow cytometry, and photosynthetic pigment data in the Atlantic sector of the Southern Ocean during March 2019 (early austral ...

    • Flow Cytometric Analysis of Bacterial Protein Synthesis: Monitoring Vitality After Water Treatment 

      Lindivat, Mathilde; Bratbak, Gunnar; Larsen, Aud; Hess-Erga, Ole-Kristian; Hoell, Ingunn Alne (Journal article; Peer reviewed, 2021)
      Bacterial vitality after water disinfection treatment was investigated using bio-orthogonal non-canonical amino acid tagging (BONCAT) and flow cytometry (FCM). Protein synthesis activity and DNA integrity (BONCAT–SYBR ...

    • How microbial food web interactions shape the arctic ocean bacterial community revealed by size fractionation experiments 

      Müller, Oliver; Seuthe, Lena; Pree, Bernadette; Bratbak, Gunnar; Larsen, Aud; Paulsen, Maria Lund (Journal article; Peer reviewed, 2021-11-17)
      In the Arctic, seasonal changes are substantial, and as a result, the marine bacterial community composition and functions differ greatly between the dark winter and light-intensive summer. While light availability is, ...

    • Marine mimivirus relatives are probably large algal viruses 

      Monier, Adam; Borggaard Larsen, Jens; Sandaa, Ruth-Anne; Bratbak, Gunnar; Claverie, Jean-Michel; Ogata, Hiroyuki (Peer reviewed; Journal article, 2008-01-23)
      Background Acanthamoeba polyphaga mimivirus is the largest known ds-DNA virus and its 1.2 Mb-genome sequence has revealed many unique features. Mimivirus occupies an independent lineage among eukaryotic viruses and its ...

    • Multiomics in the central Arctic Ocean for benchmarking biodiversity change 

      Mock, Thomas; Boulton, William; Balmonte, John-Paul; Barry, Kevin; Bertilsson, Stefan; Bowman, Jeff; Buck, Moritz; Bratbak, Gunnar; Chamberlain, Emelia J.; Cunliffe, Michael; Creamean, Jessie; Ebenhöh, Oliver; Eggers, Sarah Lena; Fong, Allison A.; Gardner, Jessie; Gradinger, Rolf Rudolf; Granskog, Mats A.; Havermans, Charlotte; Hill, Thomas; Hoppe, Clara J.M.; Korte, Kerstin; Larsen, Aud; Müller, Oliver; Nicolaus, Anja; Oldenburg, Ellen; Popa, Ovidiu; Rogge, Swantje; Schäfer, Hendrik; Shoemaker, Katyanne; Snoeijs-Leijonmalm, Pauline; Torstensson, Anders; Valentin, Klaus; Vader, Anna; Barry, Kerrie; Chen, I-M A; Clum, Alicia; Copeland, Alex; Daum, Chris; Eloe-Fadrosh, Emiley; Foster, Brian; Foster, Bryce; Grigoriev, Igor V.; Huntemann, Marcel; Ivanova, Natalia; Kuo, Alan; Kyrpides, Nikos C.; Mukherjee, Supratim; Palaniappan, Krishnaveni; Reddy, T.B.K.; Salamov, Asaf; Roux, Simon; Varghese, Neha; Woyke, Tanja; Wu, Dongying; Leggett, Richard M.; Moulton, Vincent; Metfies, Katja (Journal article; Peer reviewed, 2022-10-17)
      Multiomics approaches need to be applied in the central Arctic Ocean to benchmark biodiversity change and to identify novel species and their genes. As part of MOSAiC, EcoOmics will therefore be essential for conservation ...

    • Phenology and Environmental Control of Phytoplankton Blooms in the Kong Håkon VII Hav in the Southern Ocean 

      Kauko, Hanna Maria; Hattermann, Tore; Ryan-Keogh, Thomas J.; Singh, Asmita; de Steur, Laura; Fransson, Agneta; Chierici, Melissa; Falkenhaug, Tone; Hallfredsson, Elvar H.; Bratbak, Gunnar; Tsagaraki, Tatiana Margo; Berge, Terje; Zhou, Qin; Moreau, Sebastien (Journal article; Peer reviewed, 2021)
      Knowing the magnitude and timing of pelagic primary production is important for ecosystem and carbon sequestration studies, in addition to providing basic understanding of phytoplankton functioning. In this study we use ...

    • Removal of large viruses and their dispersal through fecal pellets of the appendicularian Oikopleura dioica during Emiliania huxleyi bloom conditions 

      Mayers, Kyle; Lawrence, Janice; Skaar, Katrine Sandnes; Töpper, Joachim Paul; Petelenz-Kurdziel, Elzbieta Anna; Saltvedt, Marius Rydningen; Sandaa, Ruth-Anne; Larsen, Aud; Bratbak, Gunnar; Ray, Jessica Louise (Journal article; Peer reviewed, 2021)
      Despite their importance in shaping the structure and function of marine microbial food webs, little is known about factors regulating marine virus abundance. Previous work demonstrated clearance of laboratory-cultured ...

    • Reproducing the virus-to-copepod link in Arctic mesocosms using host fitness optimization. 

      Thingstad, T. Frede; Larsen, Aud; Bratbak, Gunnar; Våge, Selina; Egge, Jorun Karin; Sandaa, Ruth-Anne; Nejstgaard, Jens Christian (Journal article; Peer reviewed, 2020)
      By shunting material out of the predatory pathway toward detritus and dissolved material, viruses are believed to have an important impact on biogeochemical functions of the pelagic microbial food web. To include viruses ...

    • Seasonal dynamics of haptophytes and dsDNA algal viruses suggest complex virus-host relationship 

      Johannessen, Torill Vik; Larsen, Aud; Bratbak, Gunnar; Pagarete, António; Edvardsen, Bente; Egge, Elianne Dunthorn; Sandaa, Ruth-Anne (Peer reviewed; Journal article, 2017-04-20)
      Viruses influence the ecology and diversity of phytoplankton in the ocean. Most studies of phytoplankton host–virus interactions have focused on bloom-forming species like Emiliania huxleyi or Phaeocystis spp. The role of ...

    • Seasonal variations in C:N:Si:Ca:P:Mg:S:K:Fe relationships of seston from Norwegian coastal water: Impact of extreme offshore forcing during winter-spring 2010 

      Erga, Svein Rune; Haugen, Stig Bjarne; Bratbak, Gunnar; Egge, Jorun Karin; Heldal, Mikal; Mork, Kjell Arne; Nordland, Svein (Peer reviewed; Journal article, 2017-11)
      The aim of this study was to reveal the relative content of C, N, Ca, Si, P, Mg, K, S and Fe in seston particles in Norwegian coastal water (NCW), and how it relates to biological and hydrographic processes during seasonal ...

    • Seasonality of the Physical and Biogeochemical Hydrography in the Inflow to the Arctic Ocean Through Fram Strait 

      Randelhoff, Achim; Reigstad, Marit; Chierici, Melissa; Sundfjord, Arild; Ivanov, Vladimir; Cape, Matthias; Vernet, Maria; Tremblay, Jean-Éric; Bratbak, Gunnar; Kristiansen, Svein (Peer reviewed; Journal article, 2018-06-29)
      Eastern Fram Strait and the shelf slope region north of Svalbard is dominated by the advection of warm, salty and nutrient-rich Atlantic Water (AW). This oceanic heat contributes to keeping the area relatively free of ice. ...

    • Simple models combining competition, defence and resource availability have broad implications in pelagic microbial food webs 

      Våge, Selina; Bratbak, Gunnar; Egge, Jorun Karin; Heldal, Mikal; Larsen, Aud; Norland, Svein; Paulsen, Maria Lund; Pree, Bernadette; Sandaa, Ruth-Anne; Skjoldal, Evy Foss; Tsagaraki, Tatiana Margo; Øvreås, Lise; Thingstad, T. Frede (Peer reviewed; Journal article, 2018-09)
      In food webs, interactions between competition and defence control the partitioning of limiting resources. As a result, simple models of these interactions contain links between biogeochemistry, diversity, food web structure ...