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Gunnar Bratbak

Professor
  • E-mailGunnar.Bratbak@uib.no
  • Phone+47 55 58 26 58+47 970 18 791
  • Visitor Address
    Thormøhlensgt. 53 A/B
  • Postal Address
    Postboks 7803
    5020 Bergen

The key words of my research are:

  • Structure and function of marine microbial ecosystems,
  • Carbon and nutrient flow in the microbial food web.
  • Microbial population dynamics and diversity.
  • The ecological significance of virus.
  • Ecological significance of airborne bacteria and virus.
Books
  • Bratbak, Gunnar; Heldal, Mikal; Joint, Ian. 1995. Viruses - the new players in the game; their ecologial role and could they mediate genetic exchange by transduction? ISBN: 3-540-60134-1.
Journal articles
  • Erga, Svein Rune; Haugen, Stig Bjarte; Bratbak, Gunnar; Egge, Jorun Karin; Heldal, Mikal; Mork, Kjell Arne; Norland, Svein. 2017. 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. Marine Chemistry. doi: 10.1016/j.marchem.2017.07.001
  • Johannessen, Torill Vik; Larsen, Aud; Bratbak, Gunnar; Pagarete, António; Edvardsen, Bente; Egge, Elianne Dunthorn; Sandaa, Ruth-Anne. 2017. Seasonal dynamics of haptophytes and dsDNA algal viruses suggest complex virus-host relationship. Viruses. 9. doi: 10.3390/v9040084
  • Lawrence, Janice; Töpper, Joachim Paul; Petelenz-Kurdziel, Elzbieta Anna; Bratbak, Gunnar; Larsen, Aud; Thompson, Eric; Troedsson, Christofer; Ray, Jessica Louise. 2017. Viruses on the menu: The appendicularian Oikopleura dioica efficiently removes viruses from seawater. Limnology and Oceanography.
  • Pree, Bernadette; Larsen, Aud; Egge, Jorun Karin; Simonelli, Paolo; Madhusoodhanan, Rakhesh; Tsagaraki, Tatiana; Våge, Selina; Erga, Svein Rune; Bratbak, Gunnar; Thingstad, T. Frede. 2017. Dampened copepod-mediated trophic cascades in a microzooplankton-dominated microbial food web: A mesocosm study. Limnology and Oceanography. 62: 1031-1044. doi: 10.1002/lno.10483
  • Wilson, Bryan; Müller, Oliver; Nordmann, Eva-Lena; Seuthe, Lena; Bratbak, Gunnar; Øvreås, Lise. 2017. Changes in marine prokaryote composition with season and depth over an Arctic polar year. Frontiers in Marine Science. 4. doi: 10.3389/fmars.2017.00095
  • Paulsen, Maria Lund; Doré, Hugo; Garczarek, Laurence; Seuthe, Lena; Müller, Oliver; Sandaa, Ruth-Anne; Bratbak, Gunnar; Larsen, Aud. 2016. Synechococcus in the Atlantic Gateway to the Arctic Ocean. Frontiers in Marine Science. 3:191. doi: 10.3389/fmars.2016.00191
  • Thingstad, T. Frede; Bratbak, Gunnar. 2016. Microbial Oceanography. Viral strategies at sea. Nature. 531: 454-455. doi: 10.1038/nature17303
  • Bratbak, Gunnar. 2015. On the progress of understanding algal viruses. Perspectives in Phycology. 2: 65-67. doi: 10.1127/pip/2015/0035
  • Gallot-lavallée, Lucie; Pagarete, António; Legendre, Matthieu; Santini, Sebastien; Sandaa, Ruth-Anne; Himmelbauer, Heinz; Ogata, Hiroyuki; Bratbak, Gunnar; Claverie, Jean-Michel. 2015. The 474-kilobase-pair complete genome sequence of CeV-01B, a virus infecting Haptolina (Chrysochromulina) ericina (Prymnesiophyceae). Genome Announcements. 3: 1-2. doi: 10.1128/genomeA.01413-15
  • Johannessen, Torill Vik; Bratbak, Gunnar; Larsen, Aud; Ogata, Hirotaka; Egge, Elianne Sirnæs; Edvardsen, Bente; Eikrem, Wenche; Sandaa, Ruth-Anne. 2015. Characterisation of three novel giant viruses reveals huge diversity among viruses infecting Prymnesiales (Haptophyta). Virology. 476: 180-188. doi: 10.1016/j.virol.2014.12.014
  • Larsen, Aud; Egge, Jorun Karin; Nejstgaard, Jens Christian; Di Capua, Iole; Thyrhaug, Runar; Bratbak, Gunnar; Thingstad, T. Frede. 2015. Contrasting response to nutrient manipulation in Arctic mesocosms are reproduced by a minimum microbial food web model. Limnology and Oceanography. 60: 360-374. doi: 10.1002/lno.10025
  • Pagarete, António; Grébert, Théophile; Stepanova, Olga; Sandaa, Ruth-Anne; Bratbak, Gunnar. 2015. Tsv-N1: A novel DNA algal virus that infects tetraselmis striata. Viruses. 7: 3937-3953. doi: 10.3390/v7072806
  • Carreira, Cátia; Heldal, Mikal; Bratbak, Gunnar. 2013. Effect of increased pCO(2) on phytoplankton-virus interactions. Biogeochemistry. 114: 391-397. doi: 10.1007/s10533-011-9692-x
  • Medina-Sánchez, Juan Manuel; Delgado-Molina, José Antonio; Bratbak, Gunnar; Bullejos, Francisco José; Villar-Argaiz, Manuel; Carrillo, Presentación. 2013. Maximum in the middle : nonlinear response of microbial plankton to ultraviolet radiation and phosphorus. PLoS ONE. 8. 11 pages. doi: 10.1371/journal.pone.0060223
  • Pagarete, Antonio; Lanzén, Anders; Puntervoll, Pål; Sandaa, Ruth-Anne; Larsen, Aud; Larsen, Jens Borggaard; Allen, Michael J; Bratbak, Gunnar. 2013. Genomic sequence and analysis of EhV-99B1, a new coccolithovirus from the Norwegian fjords. Intervirology. 56: 60-66. doi: 10.1159/000341611
  • Heldal, Mikal; Norland, Svein; Erichsen, Egil Severin; Sandaa, Ruth-Anne; Larsen, Aud; Thingstad, Tron Frede; Bratbak, Gunnar. 2012. Mg2+ as an indicator of nutritional status in marine bacteria. The ISME Journal. 6: 524-530. doi: 10.1038/ismej.2011.130
  • Heldal, Mikal; Norland, Svein; Erichsen, Egil Severin; Thingstad, Tron Frede; Bratbak, Gunnar. 2012. An unaccounted fraction of marine biogenic CaCO3 particles. PLoS ONE. 7. 6 pages. doi: 10.1371/journal.pone.0047887
  • Allen, Michael J; Lanzén, Anders; Bratbak, Gunnar. 2011. Characterisation of the coccolithovirus intein. Marine Genomics. 4: 1-7. doi: 10.1016/j.margen.2010.11.001
  • Bratbak, Gunnar; Jacquet, Stephan; Larsen, Aud; Pettersson, Lasse H; Sazhin, Andrey F.; Thyrhaug, Runar. 2011. The plankton community in Norwegian coastal waters-abundance, composition, spatial distribution and diel variation. Continental Shelf Research. 31: 1500-1514. doi: 10.1016/j.csr.2011.06.014
  • Fahlgren, C; Bratbak, Gunnar; Sandaa, Ruth-Anne; Thyrhaug, Runar; Zweifel, Ulla Li. 2011. Diversity of airborne bacteria in samples collected using different devices for aerosol collection. Aerobiologia. 27: 107-120. doi: 10.1007/s10453-010-9181-z
  • Liu, JingWen; Bratbak, Gunnar; Zheng, Tian Ling; Thyrhaug, Runar. 2011. Effects of virus infection on expression of cell cycle regulatory proteins in the unicellular marine algae Emiliania huxleyi. Acta Oceanologica Sinica. 30: 89-95. doi: 10.1007/s13131-011-0138-z
  • Liu, JingWen; Zheng, Tianling; Bratbak, Gunnar; Thyrhaug, Runar. 2011. Virus infection disturbs cyclin expression, leading to cell cycle arrest in the unicellular marine algae Emiliania huxleyi and Chrysochromulina ericina. African Journal of Microbiology Research. 5: 1801-1807.
  • Ogata, Hiroyuki; Ray, Jessica Louise; Toyoda, Kensuke; Sandaa, Ruth-Anne; Nagasaki, Keizo; Bratbak, Gunnar; Claverie, Jean-Michel. 2011. Two new subfamilies of DNA mismatch repair proteins (MutS) specifically abundant in the marine environment. The ISME Journal. 5: 1143-1151. doi: 10.1038/ismej.2010.210
  • Brussaard, Corina P.D.; Wilhelm, Steven W.; Thingstad, T. Frede; Weinbauer, Markus G.; Bratbak, Gunnar; Heldal, Mikal; Kimmance, Susan A.; Middelboe, Mathias; Nagasaki, Keizo; Paul, John H.; Schroeder, Declan C.; Suttle, Curtis A.; Vaqué, Dolors; Wommack, K. Eric. 2008. Global-scale processes with a nanoscale drive: the role of marine viruses. The ISME Journal. 2: 575-578. doi: 10.1038/ismej.2008.31
  • Larsen, Jens Borggaard; Larsen, Aud; Bratbak, Gunnar; Sandaa, Ruth-Anne. 2008. Phylogenetic analysis of members of the Phycodnaviridae virus family, using amplified fragments of the major capsid protein gene. Applied and Environmental Microbiology. 74: 3048-3057. doi: 10.7128/AEM.02548-07
  • Larsen, Jens Borggaard; Larsen, Aud; Thyrhaug, Runar; Bratbak, Gunnar; Sandaa, Ruth-Anne. 2008. Response of marine viral populations to a nutrient induced phytoplankton bloom at different pCO2 levels. Biogeosciences. 5: 523-533.
  • Monier, Adam; Larsen, Jens Borggaard; Sandaa, Ruth-Anne; Bratbak, Gunnar; Claverie, Jean-Michel; Ogata, Hiroyuki. 2008. Marine mimivirus relatives are probably large algal viruses. Virology Journal. 5. 8 pages. doi: 10.1186/1743-422X-5-12
  • Thingstad, T. Frede; Bellerby, Richard; Bratbak, Gunnar; Børsheim, Knut Yngve; Egge, Jorun Karin; Heldal, Mikal; Larsen, Aud; Neill, Craig Chandler; Nejstgaard, Jens Christian; Norland, Svein; Sandaa, Ruth-Anne; Skjoldal, Evy Foss; Tanaka, Tsuneo; Thyrhaug, Runar; Tøpper, Birte. 2008. Counterintuitive carbon-to-nutrient coupling in an Arctic pelagic ecosystem. Nature. 455: 387-391. Published 2008-09-18. doi: 10.1038/nature07235
  • Brussaard, Corina P.D.; Bratbak, Gunnar; Baudoux, Anne-Claire; Ruardij, Piet. 2007. Phaeocystis and its interaction with viruses. Biogeochemistry. 83: 201-215. doi: 10.1007/s10533-007-9096-0
  • Martinez, Joaquín Martínez; Schroeder, Declan C.; Larsen, Aud; Bratbak, Gunnar; Wilson, William H. 2007. Molecular dynamics of Emiliania huxleyi and cooccurring viruses during two separate mesocosm studies. Applied and Environmental Microbiology. 73: 554-562. doi: 10.1128/AEM.00864-06
  • Martínez-Martínez, Joaquin; Norland, Svein; Thingstad, Tron Frede; Schroeder, Declan C.; Bratbak, Gunnar; Wilsow, William H.; Larsen, Aud. 2006. Variability in microbial population dynamics between similarly perturbed mesocosms. Journal of Plankton Research. 28: 783-791. doi: 10.1093/plankt/fbl010
  • Yan, XD; Chipman, PR; Castberg, T; Bratbak, Gunnar; Baker, TS. 2005. The marine algal virus PpV01 has an icosahedral capsid with T=219 quasisymmetry. Journal of Virology. 79: 9236-9243.
  • Brussaard, Corina P.D.; Noordeloos, A.A.M.; Sandaa, Ruth-Anne; Heldal, Mikal; Bratbak, Gunnar. 2004. Discovery of a dsRNA virus infecting the marine photosynthetic protist Micromonas pusilla. Virology. 319: 280-291.
  • Landa, Harald; Bratbak, Gunnar; Heldal, Mikal. 2004. Abundance and dynamics of free flagellate scales in marine costal ecosystems. Aquatic Microbial Ecology. 37: 55-62.
  • Larsen, Aud; Flaten, Gro Anita Fonnes; Sandaa, Ruth-Anne; Castberg, Tonje; Thyrhaug, Runar; Erga, Svein Rune; Jacquet, Stephan; Bratbak, Gunnar. 2004. Spring phytoplankton bloom dynamics in Norwegian coastal waters: Microbial community succession and diversity. Limnology and Oceanography. 49: 180-190.
  • Larsen, Aud; Flaten, Gro Anita Fonnes; Sandaa, Ruth-Anne; Castberg, Tonje; Thyrhaug, Runar; Erga, Svein Rune; Jacquet, Stephan; Bratbak, Gunnar. 2004. Spring phytoplankton bloom dynamics in Norwegian coastal waters: Microbial community succession and diversity. Limnology and Oceanography. 49: 180-190.
  • Jacquet, Stephan; Bratbak, Gunnar. 2003. Effects of ultraviolet radiation on marine virus–phytoplankton interactions. FEMS Microbiology Ecology. 44: 279-289.
  • Sandaa, Ruth-Anne; Skjoldal, Evy Foss; Bratbak, Gunnar. 2003. Virioplankton community structure along a salinity gradient in a solar saltern. Extremophiles. 7: 347-351.
  • Thyrhaug, Runar; Larsen, Aud; Thingstad, Tron Frede; Bratbak, Gunnar. 2003. Stable coexistence in marine algal host-virus systems. Marine Ecology Progress Series. 254: 27-35.
  • Castberg, Tonje; Thyrhaug, Runar; Larsen, Aud; Sandaa, Ruth-Anne; Heldal, Mikal; van Etten, J.L.; Bratbak, Gunnar. 2002. Isolation and characterization of a virus that infects Emiliania huxleyi (Haptophyceae). Journal of Phycology. 38: 767-774.
  • Jacquet, Stephan; Heldal, Mikal; Iglesias-Rodriguez, Debora; Larsen, Aud; Wilson, William; Bratbak, Gunnar. 2002. Flow cytometric Analysis of an E. Huxleyi bloom terminated by viral infection. Aquatic Microbial Ecology. 27: 110-124.
  • Thyrhaug, Runar; Larsen, Aud; Brussaard, Corina P.D.; Bratbak, Gunnar. 2002. Cell cycle dependent virus production in marine phytoplankton. Journal of Phycology. 38: 338-343.
  • Vrede, Katarina; Heldal, Mikal; Norland, Svein; Bratbak, Gunnar. 2002. Elemental composition (C,N,P)and cell volume of exponentially growing and nutrient limited bacterioplankton. Applied and Environmental Microbiology. 68: 2965-2971.
  • Brussaard, Corina P.D.; Marie, Dominique; Thyrhaug, Runar; Bratbak, Gunnar. 2001. Flow cytometric analysis of phytoplankton viability following viral infection. Aquatic Microbial Ecology. 26: 157-166.
  • Castberg, Tonje; Larsen, Aud; Sandaa, Ruth-Anne; Brussaard, Corina P. D.; Egge, Jorun Karin; Heldal, Mikal; Thyrhaug, Runar; Van Hannen, Eric; Bratbak, Gunnar. 2001. Microbial population dynamics and diversity during a bloom of the marine coccolithophorid Emiliania huxleyi (Haptophyta). Marine Ecology Progress Series. 221: 39-46.
  • Hewson, Ian; O'Neil, Judit M; Heil, Cynthia A; Bratbak, Gunnar; Dennison, William C. 2001. Effects of concentrated viral communities on photosynthesis and community composition of cooccurring benthic microalgae and phytoplankton. Aquatic Microbial Ecology. 25: 1-10.
  • Larsen, Aud; Castberg, Tonje; Sandaa, Ruth-Anne; Brussaard, Corina P. D.; Egge, Jorun Karin; Heldal, Mikal; Paulino, Ana; Thyrhaug, Runar; Van Hannen, Eric; Bratbak, Gunnar. 2001. Population dynamics and diversity of phytoplankton, bacteria and viruses in a seawater enclosure. Marine Ecology Progress Series. 221: 47-57.
  • Sandaa, Ruth-Anne; Heldal, Mikal; Castberg, Tonje; Thyrhaug, Runar; Bratbak, Gunnar. 2001. Isolation and characterization of two viruses with large genome size infecting Chrysochromulina ericina (Prymneriophyceae) and Pyramimonas orientalis (Prasinophyceae). Virology. 290: 272-280.
  • Bratbak, Gunnar; Heldal, Mikal. 2000. Virus rule the waves - the smallest and most abundant members of marine ecosystems. Microbiology Today. 27: 171-173.
  • Brussaard, Corina P.D.; Marie, Dominique; Bratbak, Gunnar. 2000. Flow cytometric detection of viruses. Journal of Virological Methods. 85: 175-182.
  • Rodriguez, F.; Fernandez, E.; Head, R.N.; Harbour, D.S.; Bratbak, Gunnar; Heldal, Mikal. 2000. Temporal variability of viruses, bacteria, phytoplankton and zooplankton in the western English Channel off Plymouth. MANGLER.
  • Brussaard, Corina P.D.; Thyrhaug, Runar; Marie, Dominique; Bratbak, Gunnar. 1999. Flow cytometric analysis of virus infection in two marine phytoplankton species, Micromonas pusilla (Prasinophyceae) and Phaeocystis pouchetii (Prymnesiophyceae). Journal of Phycology. 35: 941-948.
  • Marie, Dominique; Brussaard, Corina P.D.; Thyrhaug, Runar; Bratbak, Gunnar; Vaulot, Daniel. 1999. Enumeration of Marine Viruses in Culture and Natural Samples by Flow Cytometry. Applied and Environmental Microbiology. 65: 45-52.
  • Bratbak, Gunnar; Jacobsen, Anita; Heldal, Mikal. 1998. Viral lysis of Phaeocystis pouchetii and bacterial secondary production. Aquatic Microbial Ecology. 16: 11-16. Published 1998-10-15.
  • Bratbak, Gunnar; Jacobsen, Anita; Heldal, Mikal. 1998. Viral lysis of Phaeocystis pouchetii and bacterial secondary production. Aquatic Microbial Ecology. 16: 11-16.
  • Bratbak, Gunnar; Jacobsen, Anita; Heldal, Mikal; Nagasaki, Keizo; Thingstad, Frede. 1998. Virus production in Phaeocystis pouchetii and its relation to host cell growth and nutrition. Aquatic Microbial Ecology. 16: 1-9. Published 1998-10-15.
  • Bratbak, Gunnar; Jacobsen, Anita; Heldal, Mikal; Nagasaki, Keizo; Thingstad, Frede. 1998. Virus production in Phaeocystis pouchetii and its relation to host cell growth and nutrition. Aquatic Microbial Ecology. 16: 1-9.
  • Malin, G.; Wilson, W.H.; Bratbak, Gunnar; Liss, P.S.; Mann, N.H. 1998. Elevated production of dimethylsulfide resulting from viral infection of cultures of <EM>Phaeocystis pouchetii</EM>. Limnology and Oceanography. 43: 1389-1393.
  • Oren, Aharon; Bratbak, Gunnar; Heldal, Mikal. 1997. Occurrence of virus-like particles in the Dead Sea. Extremophies. 1: 143-149.
  • Tuomi, P.; Torsvik, Terje; Heldal, Mikal; Bratbak, Gunnar. 1997. Bacterial population dynamics in a meromictic lake. Applied and Environmental Microbiology. 63: 2181-2188.
  • Bratbak, Gunnar; Heldal, Mikal; Thingstad, Tron Frede; Tuomi, Pirjo. 1996. Dynamics of virus abundance in coastal seawater. FEMS Microbiology Ecology. 19: 263-269.
  • Bratbak, Gunnar; Willson, William; Heldal, Mikal. 1996. Viral control of Emiliania huxleyi blooms? Journal of Marine Systems. 9: 75-81.
  • Gundersen, Kjell; Bratbak, Gunnar; Heldal, Mikal. 1996. Factors influencing the loss of bacteria in preserved seawater samples. Marine Ecology Progress Series. 137: 305-310. Published 1996-06-27.
  • Heldal, Mikal; Norland, Svein; Fagerbakke, Kjell Magne; Thingstad, Tron Frede; Bratbak, Gunnar. 1996. The elemental composition of bacteria: a signature of growth conditions? Marine Pollution Bulletin. 33: 3-9.
  • Jacobsen, Anita; Bratbak, Gunnar; Heldal, Mikal. 1996. Isolation and characterization of a virus infecting Phaeocystis pouchetii (Prymnesiophyceae). Journal of Phycology. 32: 923-927.
  • Jacobsen, Anita; Bratbak, Gunnar; Heldal, Mikal. 1996. Isolation and characterisation of a virus infecting Phaeocystis pouchetii (Haptophyceae). Journal of Phycology. 32: 923-927.
  • Bratbak, Gunnar; Levasseur, M.; Michaud, M.; Cantin, G.; Fernandez, E.; Heimdal, B.R.; Heldal, Mikal. 1995. Viral activity in relation to Emiliania huxleyi blooms: a possible mechanism of DMSP release? Marine Ecology Progress Series. 128: 133-142.
  • Bratbak, Gunnar; Levasseur, M.; Michaud, M.; Cantin, G.; Fernández, E.; Heimdal, B.R.; Heldal, Mikal. 1995. Viral activity in relation to Emiliania huxleyi blooms: a possible mechanism of DMSP release? Marine Ecology Progress Series. 128: 133-142.
  • Tuomi, Pirjo; Fagerbakke, Kjell Magne; Bratbak, Gunnar; Heldal, Mikal. 1995. Nutritional enrichment of a microbial community: The effects on activity, elemental composition, community structure and virus production. FEMS Microbiology Ecology. 16: 123-134.
  • Heldal, Mikal; Norland, Svein; Bratbak, Gunnar; Riemann, B. 1994. Determination of bacterial cell number and cell volume by means of flow cytometer, transmission electron microscopy, and epifluorescene microscopy. Journal of Microbiological Methods.
  • Bratbak, Gunnar; Egge, Jorun Karin; Heldal, Mikal. 1993. Viral mortality of the marine alga Emiliania huxleyi (Haptophyceae) and termination of algal blooms. Marine Ecology Progress Series. 93: 39-48.
  • Bratbak, Gunnar; Egge, Jorun Karin; Heldal, Mikal. 1993. Viral mortality of the marine algae Emiliania huxleyi (Haptophyceae) and termination of algal blooms. Marine Ecology Progress Series. 93: 39-48.
  • Thingstad, Tron Frede; Heldal, Mikal; Bratbak, Gunnar; Dundas, Ingrid. 1993. Are viruses important partners in pelagic food webs? Trends in Ecology & Evolution. 8: 209-213.
  • Bratbak, Gunnar; Heldal, Mikal; Thingstad, T.F; Riemann, B; Haslund, O.H. 1992. Incorporation of viruses into the budget of microbial C-transfer. A first approach. Mar.Ecol.Prog.. 83: 273-280.
  • Dundas, Ingrid; Bratbak, Gunnar; Heldal, Mikal. 1992. Roles of virus/phage in marine microbial ECOSYSTEMS. Short Communications of the 1991 International Biotechnology Conferense. 1: 146-150.
  • Heldal, Mikal; Bratbak, Gunnar. 1991. Production and decay of viruses in aquatic environments. Marine Ecology Progress Series. 72: 205-212.
  • Bratbak, Gunnar. 1990. Virus: Spiller de noen økologisk rolle? Naturen. 4: 148-152.
  • Bratbak, Gunnar; Heldal, Mikal; Norland, Svein; Thingstad, Tron Frede. 1990. Viruses as Partners in Spring Bloom Microbial Trophodynamics. Applied and Environmental Microbiology. 1400-1405.
  • Børsheim, K. Y.; Bratbak, Gunnar; Heldal, Mikal. 1990. Enumeration and biomass estimation on planktonic bacteria and viruses by transmission electron microscopy. Applied and Environmental Microbiology. 56: 352-356.
  • Bergh, Ø; Børsheim, K. Y.; Bratbak, Gunnar; Heldal, Mikal. 1989. High abundance of viruses found in aquatic environments. Nature. 340: 467-468.
Reports and theses
  • Bratbak, Gunnar. 2001. BIO 101 Basal Biologi Laboratorieøvelser i Cellebiologi. Institutt for mikrobiologi, Bergen. 102 pages.
  • Bratbak, Gunnar; et al., [Mangler fornavn]. 1998. Algal Virus Workshop : Abstracts - Program - Participiants : Bergen, Norway June 14 - 18, 1998. Department of Microbiology, University of Bergen. 27 pages.
  • Bratbak, Gunnar; Heldal, Mikal. 1997. Program and group reports from course in Microbial activity and diversity in aquatic interphases. Institutt for mikrobiologi, Universitetet i Bergen.
  • Bratbak, Gunnar. 1996. Abstracts - Program - Participants. Fifth European Marine Microbiology Symposium. Institutt for mikrobiologi, UiB.
  • Bratbak, Gunnar. 1988. Production, amount and fate of bacterial biomass in marine waters : a discussion of field methods and results in a laboratory perspective.
Book sections
  • Thingstad, T. Frede; Bratbak, Gunnar; Heldal, Mikal. 2008. Aquatic phage ecology. Kapittel. In:
    • Abedon, Stephen T. 2008. Bacteriphage ecology - population growth, evolution, and impact of bacterial viruses. Advances in molecular and cellular microbiology No. 15. Cambridge University Press. 526 pages. ISBN: 9780521858458.
  • Heldal, Mikal; Bratbak, Gunnar; Erichsen, Egil S.; Norland, Svein. 2003. X-ray microanalysis of native aquatic bacteria. 836-842. In:
    • Mendes-Vilas, A. 2003. Science, Technology and Education of Microscopy; an Overview.
  • Bratbak, Gunnar. 1993. Microscope methods for measuring bacterial biovolume: epifluorescence microscopy, scanning electron microscopy and transmission electron microscopy. In:
    • [Mangler etternavn], [Mangler fornavn]. 1993. Handbook of methods in aquatic microbial ecology. (Red.: Kemp, P. F., Sherr, B. F., Sherr, E. B., Cole, J. J.).
  • Bratbak, Gunnar; Heldal, Mikal. 1993. Total Counts of Viruses in Aquatic Environments. In:
    • [Mangler etternavn], [Mangler fornavn]. 1993. Handbook of methods in Aquatic Microbial ecology. (Red.: Kemp, P. F., Sherr, B. F., Sherr, E. B., Cole, J. J.).

More information in national current research information system (CRIStin)

ISI statistics (August, 2011): Articles: 63, Citations: 4836, h-index: 35, Citations/article: 77

Mikal Heldal, Svein Norland, Egil Severin Erichsen, Ruth-Anne Sandaa, Aud Larsen, Frede Thingstad and Gunnar Bratbak. 2011 Mg2+ as indicator of nutritional status in marine bacteria. The ISME Journal. In press

Gunnar Bratbak, Stéphan Jacquet, Aud Larsen, Lasse H. Pettersson, Andrey F. Sazhin and Runar Thyrhaug. 2011 The plankton community in Norwegian coastal waters - abundance, composition, spatial distribution and diel variation. Continental Shelf Research doi:10.1016/j.csr.2011.06.014

Allen, Michael J., Lanzén, Anders and Bratbak, Gunnar. 2011. Characterisation of the coccolithovirus intein. Marine Genomics. Marine Genomics. doi:10.1016/j.margen.2010.11.001

Hiroyuki Ogata, Jessica Ray, Kensuke Toyoda, Ruth-Anne Sandaa, Keizo Nagasaki, Gunnar Bratbak, Jean-Michel Claverie. 2011. Girus-encoded MutS subfamilies abundant in the marine environment. The ISME Journal doi:10.1038/ismej.2010.210

Camilla Fahlgren, Gunnar Bratbak, Ruth-Anne Sandaa, Runar Thyrhaug & Ulla Li Zweifel 2011. Diversity of airborne bacteria in samples collected using different devices for aerosol collection. Aerobiologia 27:107–120

Nagasaki, K and Bratbak, G 2010. Isolation of viruses infecting photosynthetic and non-photosynthetic protists. Limnology and Oceanography: Methods, Manual of Aquatic Viral Ecology (Chapter 10, 2010, 92–101) DOI 10.4319/mave.2010.978-0-9845591-0-7.92

T. F. Thingstad , R. G. J. Bellerby, G. Bratbak, K. Y. Børsheim, J. K. Egge, M. Heldal, A. Larsen, C. Neill, J. Nejstgaard, S. Norland, R.-A. Sandaa, E. F. Skjoldal, T. Tanaka, R. Thyrhaug & B. Töpper. 2008. Counterintuitive carbon-to-nutrient coupling in an Arctic pelagic ecosystem. Nature 455:387-390.

Larsen JB, Larsen A, Bratbak G and Sandaa R-A. 2008. Phylogenetic analysis of members of the Phycodnaviridae virus family using amplified fragments of the major capsid protein gene.  Appl Environ Microbiol. 74: 3048–3057.

Larsen, J. B., Larsen, A., Thyrhaug, R., Bratbak, G and Sandaa, R-A. 2008. Response of marine viral populations to a nutrient induced phytoplankton bloom at different pCO2 levels. Biogeosciences 5: 523–533.

Corina PD Brussaard, Steven W Wilhelm, Frede Thingstad, Markus G Weinbauer, Gunnar Bratbak, Mikal Heldal, Susan A Kimmance, Mathias Middelboe, Keizo Nagasaki, John H Paul, Declan C Schroeder, Curtis A Suttle, Dolors Vaque´ and K Eric Wommack. 2008.  Commentary: Global-scale processes with a nanoscale drive: the role of marine viruses. The ISME Journal 1–4.

Monier A, Larsen JB, Sandaa R-A, Bratbak G, Claverie J-M and Ogata H. 2008. Marine mimivirus relatives are probably large algal viruses. Virology Journal 2008, 5:12 doi:10.1186/1743-422X-5-12

Brussaard CPD, G Bratbak, AC Baudoux & P Ruardij 2007. Phaeocystis and its interaction with viruses. Biogeochemistry 83: 201-215.

Joaquin Martínez Martínez, Declan C. Schroeder, Aud Larsen, Gunnar Bratbak and William H. Wilson. 2007. Molcular dynamics of Emliania huxleyi and their co-occurring viruses during two separate mesocosm studies. Appl. Environ. Microbiol. 73:554-562

J. Martínez-Martínez, S. Norland T. F. Thingstad, D.C. Schroeder, G. Bratbak, W. H. Wilson, A. Larsen. 2006. Variability in microbial population dynamics between similarly perturbed mesocosms. Journal of Plankton Research. 28:783-791.

Xiaodong Yan, Paul R. Chipman, Tonje Castberg, Gunnar Bratbak, and Timothy S. Baker. 2005 The Marine Algal Virus PpV01 Has an Icosahedral Capsid with T_219 Quasisymmetry. Journal of Virology 79: 9236–9243.

Landa H, Bratbak G, Heldal M. 2004. Abundance and dynamics of free flagellate scales in marine costal ecosystems. Aquatic Microbial Ecology 37:55-62

Brussaard CPD, Noordeloos AAM, Sandaa R-A, Heldal M, Bratbak G. 2004. Discovery of a dsRNA virus infecting the marine photosynthetic protist Micromonas pusilla. Virology 319: 280-291.

Larsen, A., Fonnes, A., Sanda, R.-S., Casberg, T., Thyrhaug, R., Erga. SE., Jacquet, S and Bratbak, G. 2004.  Spring phytoplankton bloom dynamics in Norwegian coastal waters: Microbial community succession and diversity. Limnol. Oceanogr. 49:180-190.

Ruth-Anne Sandaa, Evy Foss Skjoldal and Gunnar Bratbak. 2003. Virioplankton community structure along a salinity gradient in a solar saltern. Extremophiles 7:347-351.

Thyrhaug. R., Larsen, A, Thingstad, TF, Bratbak, G. 2003. Stable coexistence in marine algal host-virus systems. Marine Ecology Progress Series. 254:27-35.

Stéphan Jacquet and Gunnar Bratbak. 2003. Effects of ultraviolet radiation on marine virus–phytoplankton interactions. FEMS Microbiology Ecology 44:279-289

Tonje Castberg, Runar Thyrhaug, Aud Larsen, Ruth-Anne Sandaa, Mikal Hedal, James L. Van Etten, Gunnar Bratbak. 2002. Isolation and characterization of a virus that infects Emiliania huxleyi (Haptophyceae). Journal of Phycology 38:767-774.

Vrede, K., Heldal, H., Norland, S. and Bratbak, G. 2002. The Elemental Composition (C, N, P) and Cell Volume of Expontially Growing and Nutrient Limited Bacterioplankton. Appl. Environ Microbiol. 68:2965-2971

Stéphan Jacquet, Mikal Heldal, Debora Iglesias-Rodriguez, Aud Larsen, William Wilson, Gunnar Bratbak. 2002.  Flow cytometric Analysis of an E. Huxleyi bloom terminated by viral infection. Aquatic Microbial Ecology 27:111-124.

Thyrhaug  R., Larsen, A, Brussaard, C.P.D., Bratbak, G. 2002. Cell cycle dependent virus production in marine phytoplankton. Journal of Phycology 38:338-343

Brussaard C, Marie D, Thyrhaug R, Bratbak G. 2001 Flow cytometric analysis of phytoplankton viability following viral infection. Aquat. Microb. Ecol. 26:157-166.

Ruth-Anne Sandaa, Mikal Heldal, Tonje Castberg, Runar Thyrhaug and Gunnar Bratbak. 2001. Isolation and characterization of two viruses with large genome size infecting Chrysochromulina ericina (Prymnesiophyceae) and Pyramimonas orientalis Prasinophyceae). Virology 290:272-280.

Larsen, A., Castberg, T., Sandaa, R-A., Brussaard, C., Egge, J., Heldal, M., Paulino, A., Thyrhaug, R., van Hannen, E. and Bratbak, G. (2001). Population dynamics and diversity of phytoplankton, bacteria and virus in a seawater enclosure. Mar. Ecol. Prog. Ser. 221:47-57.

Castberg, T., Larsen, A., Brussaard, C., Egge, J., Heldal, M., Sandaa, R-A., Thyrhaug, R., van Hannen, E. and Bratbak, G. (2001). Microbial population dynamics and diversity during blooms of the marine coccolithophorid Emiliania huxleyi (Haptophyta). Mar. Ecol. Prog. Ser. 221:39-46.

Ian Hewson, Judith M. O’Neil, Cynthia A. Heil, Gunnar Bratbak, William C. Dennison.  2001. Effects of Elevated Virus Abundance on Benthic Microbial Communities. Aquat. Microb. Ecol 25:1-10.

F. Rodríguez, E. Fernández, R.N. Head, D.S. Harbour, G. Bratbak, M. Heldal and R.P. Harris. 2000. Temporal variability of viruses, bacteria, phytoplankton and zooplankton in the western English Channel off Plymouth. J. Mar.Biol. Ass. UK. 80:575-586.

Brussaard, C.P.D., Marie, D. and Bratbak, G. 2000. Flow cytometric detection of viruses. Journal of Virological Methods. 85:175-182

Brussaard C, Thyrhaug R, Marie D, and Bratbak G. 1999 Flow cytometric analysis of virus infection in two marine phytoplankton species, Micromonas pusilla (Prasinophyceae) and Phaeocystis pouchetii (Prymnesiophyceae). Journal of Phycology 35:941-948.

Dominique Marie, Corina P. D. Brussaard, Runar Thyrhaug, Gunnar Bratbak, and Daniel Vaulot. 1999.  Enumeration of Marine Viruses in Culture and Natural Samples by Flow Cytometry Appl. Envir. Microbiol. 65: 45-52.

Malin G., Wilson W.H., Bratbak G., Liss P.S. Mann N.H. 1998. Elevated production of dimethylsulfide resulting from viral infection of cultures of Phaeocystis pouchetii. Limnol. Oceanogr. 43:1389-1393.

Bratbak G, Jacobsen A, Heldal M. 1998. Viral lysis of Phaeocystis pouchetii and bacterial secondary production. Aquat. Microb. Ecol. 16:11-16.

Bratbak G, Jacobsen A, Heldal M, Nagasaki K, Thingstad F. 1998. Virus production in Phaeocystis pouchetii and its relation to host cell growth and nutrition. Aquat. Microb. Ecol. 16:1-9.

Oren A., Bratbak, G., and Heldal M. 1997. Occurrence of virus-like particles in the Dead Sea. Extremophiles 1:143-149.

Tuomi, P., Torsvik, T. Heldal, M. and. Bratbak, G. 1997. Bacterial population dynamics in a meromictic lake. Appl. Environ. Microbiol. 63:2181-2188.

Heldal, M., Norland, S., Fagerbakke, K.M., Thingstad, T.F and. Bratbak, G, 1997. The elemental composition of bacteria: a signature of growth condition. Marine Pollution Bulletin 33:3-9.

Guixa-Boixareu Nuria, Calderón-Paz Juan I., Heldal, Mikal, Bratbak, Gunnar, Pedrós-Alió Carlos. 1996. Viral lysis and bacterivory as procaryotic loss factors along a salinity gradient. Aquatic Microb. Ecol. 11:215-227.

Heldal, M., Fagerbakke, K.M., Tuomi, P., and. Bratbak, G. 1996.  Abundant populations of iron and manganese sequestering bacteria in coastal water. Aquatic Microbial Ecology. 11:127-133.

Jacobsen, A.,  Bratbak, G. and Heldal, M. 1996. Isolation and characterisation of a virus infecting Phaeocystis pouchetii (Prymnesiophyceae). J. Phycol. 32:923-927.

Bratbak, G., Heldal, M., Thingstad, T.F. and Tuomi, P. 1996.  Dynamics of virus abundance in coastal seawater. FEMS Microbiology Ecology. 19:263-269

Kjell Gundersen, Gunnar Bratbak and Mikal Heldal. 1996. Factors influencing the loss of bacteria in preserved seawater samples. Mar. Ecol. Prog. Ser. 137: 305-310.

Bratbak, G., Willson, W. and Heldal, M. 1996. Viral control of Emiliania huxleyi blooms? Journal of Marine Systems 9:75-81.

Bratbak, G., Levasseur, M.,  Michaud, S., Cantin, G., Fernández, E., Heimdal, B.R. and Heldal, M . 1995. Viral activity in relation to Emiliania huxleyi blooms: a possible mechanism of DMSP release? Mar. Ecol. Prog. Ser. 128:133-142.

Tuomi, P., Fagerbakke, K.M., Bratbak G. and Heldal, M. 1995. Nutritional enrichment of a microbial community: the effects on activity, elemental composition, community structure and virus production. FEMS Microbiology Ecology 16:123-134.

Bratbak, G., Heldal, M., and Thingstad, T. 1994. Viruses and the microbial loop. Microbial Ecology 28:209-221.

Heldal, M., S. Norland, B. Riemann and G. Bratbak. 1994. Determination of bacterial cell number and cell volume by means of flowcytometry, TEM and epifluorescence microscopy. Journal of Microbial Methods 20:255-263.

Thingstad,T.F., Heldal,M., Bratbak,G., and Dundas,I. 1993. Are viruses important partners in pelagic food webs? Trends in Ecology and Evolution. 8:209-213.

Bratbak, G., J.K. Egge and M. Heldal. 1993. Viral mortality of the marine alga Emiliania huxleyi (Haptophyceae) and termination of algal blooms. Mar. Ecol. Prog. Ser. 93:39-48.

Bratbak, G., Haslund, O.H., Heldal, M., Næss, A., and Røeggen, T. 1992. Giant marine viruses ? Mar. Ecol. Prog. Ser. 85:201-202.

Bratbak, G., M. Heldal, T.F. Thingstad, B. Riemann and O.H. Haslund. 1992. Incorporation of viruses into the budget of microbial C-transfer. A first approach. Mar. Ecol. Prog. Ser. 83:273-280.

Heldal, M. and G. Bratbak. 1991. Production and decay of viruses in marine waters. Mar. Ecol. Prog. Ser. 72: 205-212.

Bratbak, G., M. Heldal, S. Norland, and T.F. Thingstad. 1990. Viruses as partners in spring bloom microbial trophodynamics. Appl. Environ. Microbiol 56:1400-1405.

Børsheim, Y., G. Bratbak, and M. Heldal. 1990.  Enumeration and biomass estimation of planktonic bacteria and viruses by transmission electron microscopy. Appl. Environ. Microbiol. 56: 352-356.

Bergh, Ø., K.Y.Børsheim, G. Bratbak, and M. Heldal. 1989. High abundance of viruses found in aquatic environments. Nature 340: 467-468.

Bratbak, G. 1987. Carbon flow in an experimental microbial  ecosystem.  Mar. Ecol. Prog. Ser. 36: 267-276.

Børsheim, K.Y., and G. Bratbak. 1987.  Cell volume to cell carbon conversion factors for a bacterivorous Monas sp. enriched from seawater.  Mar. Ecol. Prog. Ser. 36: 171-175.

Bratbak, G., and T.F. Thingstad. 1985. Phytoplankton-bacteria interactions: an apparent paradox? Analysis of a model system with both competition and commensalism. Mar. Ecol. Prog. Ser. 25: 23-30.

Bratbak, G. 1985. Bacterial biovolume and biomass estimations. Appl. Environ. Microbiol. 49: 1488-1493.

Bratbak, G., and I. Dundas. 1984. Bacterial dry matter content and biomass estimations.  Appl. Environ. Microbiol. 48: 755-757.

Bratbak, G., M. Heldal, G. Knutsen T. Lien, and S. Norland. 1982. Correlation of dispersant effectiveness and toxicity of oil dispersants towards the alga Chlamydomonas reinhardti. Marine Pollution Bulletin 13: 351-353.

 

Cand. real.  1981

Dr. philos.  1988

Research groups