Viruses are the most abundant biological entities on the planet. In one drop of seawater there is as many as one million viruses. This means that there are more viruses in one litre of seawater than humans on our planet. Most of these viruses infect microbes, that is bacteria, archaea and phytoplankton, the main primary producers of the world’s oceans. By infecting and killing these microbes, viruses affect all microbial processes, such as global fixation and cycling of key elements e.g. carbon, nitrogen and phosphorous. However, not all viruses cause harm to their hosts. Some have developed different ways to “live” in peace with their host or even being beneficial for host survival. How these different forms of relationships are established, and how they affect the function of the host community, is however unknown. My primary research objective is to discover basic mechanisms of virus-host interaction that contribute to a general understanding of how viruses affect the biodiversity of their host population in the marine microbial foodweb.

Research topics:

• Describe and qualify the dynamics and diversity of viral communities and their effects on the host community in natural and experimental ecosystems.
• Gain fundamental knowledge of how marine algal viruses and their phytoplankton hosts evolve from an acute disease state to peaceful co-existence by examining specific traits (fitness traits/trade-offs)
• Uncovering the keys to success of viruses in Artic marine environments

Academic article

• Eliana Ruiz Martinez; Dean A. Mckeown; Decland C. Schroeder et al. (2023). Phaeoviruses Present in Cultured and Natural Kelp Species, Saccharina latissima and Laminaria hyperborea (Phaeophyceae, Laminariales), in Norway. (external link)
• J.T.R Basso; N.Y.D Ankrah; M.J. Tuttle et al. (2020). Genetically similar temperate phages form coalitions with their shared host that lead to niche-specific fitness effects.. (external link)
• Hiroyuki Ogata; Jessica Louise Ray; Kensuke Toyoda et al. (2011). Two new subfamilies of DNA mismatch repair proteins (MutS) specifically abundant in the marine environment. (external link)
• Ruth-Anne Sandaa; Ø. Enger (1994). Transfer in Marine sediments of the naturally occuring plasmid pRAS1 encoding multiple antibiotic resistance. (external link)
• Sandra Gran Stadniczeñko; Anders Kristian Krabberød; Ruth-Anne Sandaa et al. (2019). Seasonal dynamics of algae-infecting viruses and their inferred interactions with protists. (external link)
• Jens Borggaard Larsen; Aud Larsen; Gunnar Bratbak et al. (2008). Phylogenetic analysis of members of the Phycodnaviridae virus family, using amplified fragments of the major capsid protein gene. (external link)
• Eliana Ruiz Martinez; Monique Oosterhof; Ruth-Anne Sandaa et al. (2017). Emerging interaction patterns in the Emiliania huxleyi-EhV system. (external link)
• Ruth-Anne Sandaa; Øivind Enger; Vigdis Lid Torsvik (1999). Abundance and diversity of Archaea in heavy-metal contaminated soils. (external link)
• Mekonnen Kurabachew; Ruth-Anne Sandaa; Øivind Enger et al. (2003). Sequence analysis in the 23S rDNA region of Mycobacterium tuberculosis and related species. (external link)
• Lise Øvreås; David Bourne; Ruth-Anne Sandaa et al. (2003). Response of bacterial and viral communities to nutrient manipulations in seawater mesocosms. (external link)
• Jessica Louise Ray; Michael Dondrup; Sejal Modha et al. (2012). Finding a needle in the virus metagenome haystack - micro-metagenome analysis captures a snapshot of the diversity of a bacteriophage armoire. (external link)
• Paraskevi Pitta; Jens Christian Nejstgaard; Tatiana Tsagaraki et al. (2016). Confirming the "rapid phosphorus transfer from microorganisms to mesozooplankton in the eastern mediterranean sea" scenario through a mesocosm experiment. (external link)
• Haina Wang; Lingjie Meng; Sara Otaegi Ugartemendia et al. (2025). Haptophyte-infecting viruses change the genome condensing proteins of dinoflagellates. (external link)
• Tonje Castberg; Aud Larsen; Ruth-Anne Sandaa et al. (2001). Microbial population dynamics and diversity during a bloom of the marine coccolithophorid Emiliania huxleyi (Haptophyta). (external link)
• Ruth-Anne Sandaa; Vigdis Torsvik; Øivind Enger (2001). Influence of long-term heavy-metal contamination on microbial communities in soil. (external link)
• Tron Frede Thingstad; Selina Våge; Julia Endresen Storesund et al. (2014). A theoretical analysis of how strain-specific viruses can control microbial species diversity. (external link)
• Ruth-Anne Sandaa; Vigdis Lid Torsvik; J Goksøyr (1992). Transferable drug resistance in bacteria isolated from fish farm sedime ents. (external link)
• Antonio Pagarete; Cheryl-Emiliane T. Chow; Torill Vik Johannessen et al. (2013). Strong seasonality and interannual recurrence in marine myovirus communities. (external link)
• C Fahlgren; Gunnar Bratbak; Ruth-Anne Sandaa et al. (2011). Diversity of airborne bacteria in samples collected using different devices for aerosol collection. (external link)
• Aud Larsen; Gro Anita Fonnes Flaten; Ruth-Anne Sandaa et al. (2004). Spring phytoplankton bloom dynamics in Norwegian coastal waters: Microbial community succession and diversity. (external link)
• Ruth-Anne Sandaa; Julia Endresen Storesund; Emily Maria Olesin et al. (2018). Seasonality drives microbial community structure, shaping both eukaryotic and prokaryotic host–viral relationships in an Arctic marine ecosystem. (external link)
• Ruth-Anne Sandaa; Bernadette Pree; Aud Larsen et al. (2017). The response of heterotrophic prokaryote and viral communities to labile organic carbon inputs is controlled by the predator food chain structure. (external link)
• Ruth-Anne Sandaa; Thorolf Magnesen; Lise Torkildsen et al. (2003). Characterisation of bacterial communities associated with early life stages of cultured Great Scallop, Pecten maximus using Denaturing Gradient Gel Electrophoresis (DGGE). (external link)
• Ruth-Anne Sandaa; Aud Larsen (2006). Seasonal variations in virus-host populations in Norwegian coastal waters: Focusing on the cyanophage community infecting marine Synechococcus spp. (external link)
• Emma Tarrant; Isabel G Cormack; Charlotte E Hunter et al. (2026). Structure, function, and applications of two novel phage recombinases from extreme environments. (external link)
• T. Frede Thingstad; Selina Våge; Gunnar Bratbak et al. (2020). Reproducing the virus-to-copepod link in Arctic mesocosms using host fitness optimization.. (external link)
• Ruth-Anne Sandaa; Mikal Heldal; Tonje Castberg et al. (2001). Isolation and characterization of two viruses with large genome size infecting Chrysochromulina ericina (Prymneriophyceae) and Pyramimonas orientalis (Prasinophyceae). (external link)
• Jens Borggaard Larsen; Aud Larsen; Runar Thyrhaug et al. (2008). Response of marine viral populations to a nutrient induced phytoplankton bloom at different pCO2 levels. (external link)
• Laila Brunvold; Ruth-Anne Sandaa; Helene Mikkelsen et al. (2007). Characterisation of bacterial communities associated with intensively reared cod (Gadus morhua) larvae using Denaturing Gradient Gel Electrophoresis (DGGE). (external link)
• Ruth-Anne Sandaa; Laura Gomez-Consarnau; Jarone Pinhassi et al. (2009). Viral control of bacterial biodiversity - evidence from a nutrient-enriched marine mesocosm experiment. (external link)
• Ruth-Anne Sandaa (2008). Burden or benefit? Virus-host interactions in the marine environment. (external link)
• Dawn B. Goldsmith; Giuseppe Crosti; Bhakti Dwivedi et al. (2011). Development of phoH as a Novel Signature Gene for Assessing Marine Phage Diversity. (external link)
• Sven Le Moine Bauer; Anne Stensland; Frida Lise Daae et al. (2018). Water masses and depth structure prokaryotic and T4-like viral communities around hydrothermal systems of the Nordic Seas. (external link)
• Corina P.D. Brussaard; A.A.M. Noordeloos; Ruth-Anne Sandaa et al. (2004). Discovery of a dsRNA virus infecting the marine photosynthetic protist Micromonas pusilla. (external link)
• Aud Larsen; Gro Anita Fonnes Flaten; Ruth-Anne Sandaa et al. (2004). Spring phytoplankton bloom dynamics in Norwegian coastal waters: Microbial community succession and diversity. (external link)
• Ruth-Anne Sandaa; Marius Rydningen Saltvedt; Håkon Dahle et al. (2021). Adaptive evolution of viruses infecting marine microalgae (haptophytes), from acute infections to stable coexistence. (external link)
• Torill Vik Johannessen; Aud Larsen; Gunnar Bratbak et al. (2017). Seasonal dynamics of haptophytes and dsDNA algal viruses suggest complex virus-host relationship. (external link)
• Ruth-Anne Sandaa; Thorolf Magnesen (2003). Characterization of the bacterial community associated with early stages of great scallop (Pecten maximus) using denaturing gradient gel electrophoresis (DGGE). (external link)
• Kyle Mayers; Janice Lawrence; Katrine Sandnes Skaar et al. (2021). Removal of large viruses and their dispersal through fecal pellets of the appendicularian Oikopleura dioica during Emiliania huxleyi bloom conditions. (external link)
• Ruth-Anne Sandaa; Gunnar Bratbak (2018). Is the virus important? And some other questions. (external link)
• Ruth-Anne Sandaa (1993). Transfer and maintenance of the plasmid RP4 in marine sediments. (external link)
• Daniella Schatz; Guy Schleyer; Marius Rydningen Saltvedt et al. (2021). Ecological significance of extracellular vesicles in modulating host-virus interactions during algal blooms. (external link)
• Eliana Ruiz Martinez; Anne-Claire Baudoux; Nathalie Simon et al. (2017). Micromonas versus virus: New experimental insights challenge viral impact. (external link)
• Aud Larsen; Tonje Castberg; Ruth-Anne Sandaa et al. (2001). Population dynamics and diversity of phytoplankton, bacteria and viruses in a seawater enclosure. (external link)
• S. R. Andersen; Ruth-Anne Sandaa (1994). Distribution of tetracycline resistant determinants among Gram.... (external link)
• Ruth-Anne Sandaa; Laila Brunvold; Thorolf Magnesen et al. (2008). Monitoring the opportunistic bacteria Pseudoalteromonas sp. LT-13 in a great scallop, Pecten maximus hatchery. (external link)
• Ruth-Anne Sandaa (1994). Spredning av antibiotikaresistens blandt bakterier fra .... (external link)
• Lucie Gallot-lavallée; António Pagarete; Matthieu Legendre et al. (2015). The 474-kilobase-pair complete genome sequence of CeV-01B, a virus infecting Haptolina (Chrysochromulina) ericina (Prymnesiophyceae). (external link)
• A. Rozenberg; J. Opperman; J. Wietek et al. (2020). Lateral gene transfer of anion-conducting channelrhodopsins between green algae and giant viruses. (external link)
• Jessica Louise Ray; Birte Tøpper; Shu An et al. (2012). Effect of increased pCO2 on bacterial assemblage shifts in response to glucose addition in Fram Strait seawater mesocosms. (external link)
• Julia Endresen Storesund; Svein Rune Erga; Jessica Louise Ray et al. (2015). Top-down and bottom-up control on bacterial diversity in a western Norwegian deep-silled fjord. (external link)
• Kyle Mayers; Constanze Kuhlisch; Jonelle T. R. Basso et al. (2023). Grazing on Marine Viruses and Its Biogeochemical Implications. (external link)
• Antonio Pagarete; Anders Lanzén; Pål Puntervoll et al. (2013). Genomic sequence and analysis of EhV-99B1, a new coccolithovirus from the Norwegian fjords. (external link)
• Birte Tøpper; Tron Frede Thingstad; Ruth-Anne Sandaa (2013). Effects of differences in organic supply on bacterial diversity subject to viral lysis. (external link)
• Ruth-Anne Sandaa; Ø. Enger (1996). High frequency transfer of a broad host range plasmid present in an atypical strain of the fish pathogen Aeromonas salmonicida. (external link)
• Hasan ARSIN; Andrius Jasilionis; Håkon Dahle et al. (2021). Exploring codon adjustment strategies towards Escherichia coli-based production of viral proteins encoded by HTH1, a novel prophage of the marine bacterium Hypnocyclicus thermotrophus. (external link)
• Ruth-Anne Sandaa; Evy Foss Skjoldal; Gunnar Bratbak (2003). Virioplankton community structure along a salinity gradient in a solar saltern. (external link)
• T. Frede Thingstad; Richard Bellerby; Gunnar Bratbak et al. (2008). Counterintuitive carbon-to-nutrient coupling in an Arctic pelagic ecosystem. (external link)
• Jesslyn Tjendra; Julia Endresen Storesund; Håkon Dahle et al. (2023). Molecular evidence of parallel evolution in a cyanophage. (external link)
• Terje Van der Meeren; Laila Brunvold; Ruth-Anne Sandaa et al. (2011). Water quality and microbial community structure in juvenile Atlantic cod (Gadus morhua L.) cultures. (external link)
• Torill Vik Johannessen; Gunnar Bratbak; Aud Larsen et al. (2015). Characterisation of three novel giant viruses reveals huge diversity among viruses infecting Prymnesiales (Haptophyta). (external link)
• M Kurabachew; O Enger; Ruth-Anne Sandaa et al. (2004). A multiplex polymerase chain reaction assay for genus-, group- and species-specific detection of mycobacteria. (external link)
• Ø. Enger; Ruth-Anne Sandaa (1994). Immunomagnetic beads as a tool in conjugation experiments. (external link)
• Birte Tøpper; Aud Larsen; Tron Frede Thingstad et al. (2010). Bacterial community composition in an Arctic phytoplankton mesocosm bloom: the impact of silicate and glucose. (external link)
• Tonje Castberg; Runar Thyrhaug; Aud Larsen et al. (2002). Isolation and characterization of a virus that infects Emiliania huxleyi (Haptophyceae). (external link)
• Maria Lund Paulsen; Hugo Doré; Laurence Garczarek et al. (2016). Synechococcus in the Atlantic Gateway to the Arctic Ocean. (external link)
• Jessica Louise Ray; Liti Haramaty; Runar Thyrhaug et al. (2014). Virus infection of Haptolina ericina and Phaeocystis pouchetii implicates evolutionary conservation of programmed cell death induction in marine haptophyte-virus interactions. (external link)
• Romain Blanc-Mathieu; Håkon Dahle; Antje Hofgaard et al. (2021). A persistent giant algal virus, with a unique morphology, encodes an unprecedented number of genes involved in energy metabolism. (external link)
• Ruth-Anne Sandaa; Martha Clokie; Nicholas H. Mann (2008). Photosynthetic genes in viral populations with a large genomic size range from Norwegian coastal waters. (external link)
• António Pagarete; Théophile Grébert; Olga Stepanova et al. (2015). Tsv-N1: A novel DNA algal virus that infects tetraselmis striata. (external link)
• Ruth-Anne Sandaa; Vigdis Lid Torsvik; Øivind Enger et al. (1999). Analysis of bacterial communities in heavy metal contaminated soils at different levels of resolution. (external link)
• Vigdis Lid Torsvik; Frida Lise Daae; Ruth-Anne Sandaa et al. (1998). Novel techniques for analysing microbial diversity in natural and perturbed environments. (external link)
• Ruth-Anne Sandaa; Øivind Enger; Vigdis Lid Torsvik (1998). Rapid method for fluorometric quantification of DNA in soil. (external link)
• António Pagarete; Kanthida Kusonmano; Kjell Petersen et al. (2014). Dip in the gene pool: Metagenomic survey of natural coccolithovirus communities. (external link)
• Adam Monier; Jens Borggaard Larsen; Ruth-Anne Sandaa et al. (2008). Marine mimivirus relatives are probably large algal viruses. (external link)
• Elianne Sirnæs Egge; Torill Vik Johannessen; Tom Andersen et al. (2015). Seasonal diversity and dynamics of haptophytes in the Skagerrak, Norway, explored by high-throughput sequencing. (external link)
• Julia Endresen Storesund; Ruth-Anne Sandaa; T. Frede Thingstad et al. (2017). Linking bacterial community structure to advection and environmental impact along a coast-fjord gradient of the Sognefjord, western Norway. (external link)
• Mekonnen Kurabachew; Øivind Enger; Ruth-Anne Sandaa et al. (2003). Amplified ribosomal DNA restriction analysis in the differentiation of related species of mycobacteria. (external link)
• Antonis Chatzinotas; Ruth-Anne Sandaa; Wilhelm Schönhuber et al. (1998). Analysis of broad-scale differences in microbial community composition of two pristine forest soils. (external link)
• Mikal Heldal; Svein Norland; Egil Severin Erichsen et al. (2012). Mg2+ as an indicator of nutritional status in marine bacteria. (external link)

Conference lecture

• Ruth-Anne Sandaa (2024). How can low abundant host and viruses coexist in the ocean?. (external link)
• Ruth-Anne Sandaa; Mikal Heldal; Tonje Castberg et al. (2000). Isolation and characterization of two marine viruses infecting Chrysochromulina ericina and Pyramimonas orientalis. (external link)
• Tonje Castberg; Ruth-Anne Sandaa; Gunnar Bratbak (2000). Bacterial population dynamics and diversity after viral lysis of three different algal species. (external link)
• Corina P.D. Brussaard; Ruth-Anne Sandaa; Gunnar Bratbak (2000). Infection of Micromonas pusilla (Prasinophyceae) by a dsRNA virus. (external link)
• Ruth-Anne Sandaa; Aud Larsen; Tron Frede Thingstad (2005). Viral diversity in the marine environment. Effect on the species richness and activity of planktonic organisms. (external link)
• Ruth-Anne Sandaa (2017). Marine viruses small but ecologically important. (external link)
• Jessica Louise Ray; Torill Vik Johannessen; Brian C. Wilson et al. (2016). Development of a semi-automated method for metagenomic characterization of total virus assemblages from seasonal high-latitude seawater samples. (external link)
• Ruth-Anne Sandaa; Vigdis Lid Torsvik (1996). Changes in the microbial diversity in soil due to heavy metal contamination. (external link)
• Vigdis Lid Torsvik; Karine Drønen; Ruth-Anne Sandaa et al. (1997). Monitoring environmental impact of antropogenic activity on microbial communities. (external link)
• Runar Thyrhaug; Jørn Einen; Ruth-Anne Sandaa et al. (2007). Total numbers and activity of environmental airborne bacteria. (external link)
• Marius Rydningen Saltvedt; Haina Wang; Håkon Dahle et al. (2023). PERSISTENT VIRUS PRODUCTION BY PHYTOPLANKTON. (external link)
• Bente Edvardsen; Elianne Sirnæs Egge; Torill Vik Johannessen et al. (2014). Diversity and seasonal dynamics of marine haptophytes and their viruses. (external link)
• Haina Wang; Marius Rydningen Saltvedt; Romain Blanc-Mathieu et al. (2022). Genomes of two giant viruses and their capacity in the infection cycles. (external link)
• Ruth-Anne Sandaa (2023). How do low abundant viruses and their host survive in the ocean?. (external link)
• Berit Kristine Thorsen; Ruth-Anne Sandaa; Kibret Yimer Mazengia et al. (1998). Transfer of the naturally occuring plasmid pRAS1 affects the microbiological diversity in marine sediments [poster]. (external link)
• Ruth-Anne Sandaa (2006). Viral community analysis. (external link)
• Ruth-Anne Sandaa (2016). Marine Viruses, small but major players in the ocean ecosystem. (external link)
• Ruth-Anne Sandaa (2017). Marine viruses, small but important. (external link)
• Anne Elisabeth Bjune; Gunnar Bratbak; Sigrunn Eliassen et al. (2023). Omlegging fra tradisjonelle forelesninger til studentaktiv læring – eksempel fra et grunnemne i biolog. (external link)
• Ruth-Anne Sandaa (2016). Marine Viruses are small but important. (external link)
• Ruth-Anne Sandaa; Vigdis Lid Torsvik (1996). Molecular methods for investigating changes in microbial communities. (external link)
• Ruth-Anne Sandaa (2021). Algal virus infection strategies and their effect on host diversity. (external link)
• Ruth-Anne Sandaa; Laila Brunvold; Anita Jakobsen et al. (2003). CHARACTERISATION OF BACTERIAL COMMUNITIES ASSOCIATED WITH EARLY LIFE STAGES OF CULTURED GREAT SCALLOP (PECTEN MAXIMUS), USING DENATURING GRADIENT GEL ELECTROPHORESIS (DGGE). (external link)
• Antonio Pagarete; Pål Puntervoll; Anders Lanzén et al. (2011). Geographic segregation and mechanisms of genetic evolution between coccolithovirus populations: a genomic study. (external link)
• A.G. Eide; K.Y. Mazengia; Vigdis Lid Torsvik et al. (1998). Spread of the plasmid pRAS1 in sea water and marine sediment - characterization of recipients [poster]. (external link)
• Ruth-Anne Sandaa (2020). Diversity in marine virus-host relationships and their effect of phytoplankton community structure.. (external link)
• Ruth-Anne Sandaa; Aud Larsen; Tonje Castberg et al. (2000). Population dynamics in the virioplankton community during marine algal blooms. (external link)
• Elianne Sirnæs Egge; Wenche Eikrem; Vladyslava Hostyeva et al. (2012). Diversity and seasonal dynamics of haptophytes in outer Oslofjorden revealed by 454 pyrosequencing. (external link)
• Bente Edvardsen; Elianne Sirnæs Egge; Sandra Gran Stadniczenko et al. (2015). Diversity, seasonal dynamics and biotic interactions in marine phytoplankton and virus communities. (external link)
• Ruth-Anne Sandaa (2005). VIRAL DIVERSITY IN THE MARINE ENVIRONMENT. EFFECT ON THE SPECIES RICHNESS OF PLANKTONIC ORGANISMS. (external link)
• Ruth-Anne Sandaa; Gunnar Bratbak (2004). Viral diversity in solar saltern. (external link)
• Jessica Louise Ray; Janice Lawrence; Elzbieta Anna Petelenz-Kurdziel et al. (2016). Role of appendicularians in aquatic viral ecology: particle trapping, ingestion and consequences for the marine microbial food web. (external link)
• Gunnar Bratbak; Corina P. D. Brussaard; Tonje Castberg et al. (2000). Diversity and succession of algae, virus and bacteria in nutrient enriched seawater enclosures. (external link)
• Aud Larsen; Runar Thyrhaug; Ruth-Anne Sandaa et al. (2002). Marine phytoplankton viruses - ecology, physiology and host virus interactions. (external link)
• Anita Jacobsen; J Martinez-Martinez; P Verity et al. (2005). Are colonies or colonial cells of Phaeocystis pouchetii (prymnesiophyceae) susceptible to virus infection?. (external link)
• Jessica Louise Ray; Aud Larsen; Ruth-Anne Sandaa (2009). Live and let die: Molecular methods for studying host-virus interactions using Chrysochromulina ericina and CeV-01B as a model system. (external link)
• Ruth-Anne Sandaa; B Töpper; Aud Larsen et al. (2012). Viruses, a controlling force on prokaryotic diversity?. (external link)
• Ruth-Anne Sandaa (2018). Reluctant affairs-algal virus-haptophyte relationship in the Ocean.. (external link)
• Ruth-Anne Sandaa (2018). Diversity of marine prymnesioviruses and their strategies for stable co-existence with their phytoplankton hosts. (external link)
• Øivind Enger; Ruth-Anne Sandaa (1998). Bacterial activity and diversity measured by differential-PCR. (external link)
• Bente Edvardsen; Elianne Sirnæs Egge; Sandra Gran Stadniczenko et al. (2015). Diversity and seasonal dynamics of marine haptophytes and their viruses and the role of biotic interactions. (external link)
• Ruth-Anne Sandaa; Jessica Louise Ray; Francois Enoult et al. (2017). Light and depth - main drivers of marine virus diversity and dynamics in the Arctic - Metagenomic analysis of total viral assemblages from surface to the deep. (external link)
• Bente Edvardsen; Elianne Sirnæs Egge; Johannessen Torill Vik et al. (2013). Diversity and dynamics of marine haptophytes and their viruses. (external link)
• Vigdis Lid Torsvik; Frida Lise Daae; Ruth-Anne Sandaa et al. (1997). Novel techniques for analysing microbial diversity in natural and perturbed environments. (external link)
• Ruth-Anne Sandaa (2007). Burden or Benefit- virus-host interactions in the marine environment. (external link)
• Jessica Louise Ray; François Enault; Torill Vik Johannessen et al. (2017). from light to dark and shallow to deep: Metagenomic analysis of total virus assemblages from arctic seawater provides a first glance of season- and depth-driven virus diversity and dynamics. (external link)
• Elianne Sirnæs Egge; Wenche Eikrem; Vladyslava Hostyeva et al. (2012). Diversity and seasonal dynamics of haptophytes in outer Oslofjorden revealed by 454 pyrosequencing. (external link)
• Tatiana Tsagaraki; Jorun Karin Egge; Gunnar Bratbak et al. (2017). Microbial Food web structure in a changing Arctic.. (external link)
• T.F. Thingstad; Richard Bellerby; Gunnar Bratbak et al. (2008). Increased level of CO2 in the ecosphere may modify the structure of marine plankton. (external link)
• Ruth-Anne Sandaa; Romain Blanc-Mathieu; Håkon Dahle et al. (2019). Friends or foes, strategies for stable co-existance in algel viruses infecting haptophytes. (external link)
• Jessica Louise Ray; Liti Haramaty; Helen F Fredricks et al. (2010). Host-viruses interactions in blooming and non-blooming haptophytes. (external link)
• Ruth-Anne Sandaa; Frida Lise Daae; Tonje Catberg et al. (1998). Changes im the microbiological community structure and diversity in metal contaminated soils. (external link)
• Ruth-Anne Sandaa; Berit Kristine Thorsen; Kibret Yimer Mazengia et al. (1998). Transfer of the naturally occuring plasmid pRAS1 affects the microbialdiversity in marine sediments. (external link)
• Maria Lund Paulsen; Hugo Doré; Laurence Garczarek et al. (2017). Synechococcus in the Arctic Ocean. (external link)
• Corina Brussaard; Ruth-Anne Sandaa; Mikal Heldal (2001). The discovery of a novel algal virus type infecxtion of the phytoplankter Micromonas pusilla by a double stranded RNA reovirus. (external link)
• Ruth-Anne Sandaa; Vigdis Lid Torsvik (1996). Effect of heavy metal contamination on the microbial community structure in soil. (external link)
• Aud Larsen; Tonje Castberg; Ruth-Anne Sandaa et al. (2002). Marine Phytoplankton Viruses-Ecology, Physiology and Host Virus Interactions. (external link)
• Ruth-Anne Sandaa (2024). How low abundant viruses and their hosts coexist in the ocean. (external link)

Academic book chapter

• Ruth-Anne Sandaa; Steven M. Short; Declan C. Schroeder (2010). Fingerprinting aquatic virus communities. (external link)
• Vigdis Torsvik; Frida L. Daae; Ruth-Anne Sandaa et al. (2000). Molecular biology and genetic diversity of microorganisms. (external link)

Media interview

• Ruth-Anne Sandaa; Aud Larsen; Ivar Grydeland (2004). Maneter, virus og bakterier. (external link)

Lecture

• Ruth-Anne Sandaa (2013). Unexpected diversity in algal viruses. (external link)
• Ruth-Anne Sandaa (1993). Antibiotika-resistens i oppdrettsanlegg. Hvor kommer den fra - hvordan kan den spres?. (external link)
• Aud Larsen; Ruth-Anne Sandaa (2007). Av og til er en nanometer nok. (external link)
• Runar Thyrhaug; Aud Larsen; Gunnar Bratbak et al. (2010). Use of flow cytometry in air and marine microbiological research. (external link)
• Ruth-Anne Sandaa (1993). Antibiotika resistens i oppdrettsanlegg. (external link)
• Ruth-Anne Sandaa; Birte Töpper; Aud Larsen et al. (2013). VIRUSES, CONTROLLING FORCE ON HOST DIVERSITY? -Life in the fast-line,. (external link)
• Ruth-Anne Sandaa (2007). Virus-viktig økologisk faktor i havet. (external link)
• Berit Kristine Thorsen; Ruth-Anne Sandaa; Øivind Enger (1996). Plasmid diversity in Icelandic hot springs. (external link)
• Ruth-Anne Sandaa (1993). Gene-transfer in marine sediments. (external link)
• Ruth-Anne Sandaa; Marius Rydningen Langvad; Håkon Dahle et al. (2025). The paradox of virus-host coexistence in the ocean. (external link)
• Ruth-Anne Sandaa (1993). Gene transfer between bacteria in marine sediments. (external link)
• Marius Rydningen Saltvedt; Janice Lawrence; Haina Wang et al. (2021). Vital and all over the place – A neglected group of frenemy viruses. (external link)

Conference poster

• Hasan Arsin; Anita-Elin Fedøy; Victoria Røyseth et al. (2020). Enzyme discovery from the edge of (sequence) space. (external link)
• Jessica Louise Ray; Liti Haramaty; Helen F Fredricks et al. (2010). Host-viruses interactions in blooming and non-blooming haptophytes. (external link)
• Eliana Ruiz Martinez; Aud Larsen; Ruth-Anne Sandaa et al. (2024). Phaeoviruses present in cultured and natural kelp species, Saccharina latissima and Laminaria hyperborea (Phaeophyceae, Laminariales), in Norway.. (external link)
• Jessica U. Kegel; Torill Vik Johannessen; Uwe John et al. (2016). RNA-Seq analysis of host and viral gene expression highlights the interaction between Prymnesium kappa and the virus HeV-RF02.. (external link)
• Ruth-Anne Sandaa; Torill Johanessen; Janice Lawrence et al. (2017). Diversity of novel viruses infecting haptophytes. (external link)
• Sven Le Moine Bauer; Ida Helene Steen; Ruth-Anne Sandaa et al. (2014). Microbial community changes within a chimney wall at the basalt-hosted Jan Mayen vent field (JMVF):Modeled predictions vs. Pyrosequencing data. (external link)
• Jessica Louise Ray; Ruth-Anne Sandaa; Aud Larsen (2011). Virus resistance in eukariotic marine phytoplankton - a status update. (external link)
• Ruth-Anne Sandaa; Ø. Enger (1993). Transfer of a broad host range plasmid from Aeromonas salmonicida to bacteria indigenous to the marine environment. (external link)
• Ruth-Anne Sandaa; Øyvind Enger (1993). In situ transfer in the marine environment of a broad host range plasmid indigenious to Aeromonas salmonicida. (external link)
• Gunnar Bratbak; Corina Brussaard; Tonje Castberg et al. (1999). Virus i Havet. (external link)
• Jessica Louise Ray; Ruth-Anne Sandaa; Aud Larsen (2011). Virus resistance in marine phytoplankton - a status update. (external link)
• Ruth-Anne Sandaa; Aud Larsen; Tron Frede Thingstad (2004). Microbial biodiversity control. (external link)
• Aud Larsen; Ruth-Anne Sandaa; Runar Thyrhaug et al. (2011). Pelagiske virus i Kongsfjord. (external link)
• Laila Brunvold; Ruth-Anne Sandaa; Anita Jakobsen et al. (2003). Inlet water flown over a biofilm with probiotic bacteria-a possible strategy to increase survival of scallop larvae?. (external link)
• Marius Rydningen Saltvedt; Haina Wang; Janice Lawrence et al. (2022). Friend or enemy: The story of a frenemy relationship between a virus and its host. (external link)
• Ruth-Anne Sandaa; Gunnar Bratbak (2000). A method for diversity analysis of viruses in small volumes of seawater. (external link)
• Haina Wang; Marius Rydningen Saltvedt; Romain Blanc-Mathieu et al. (2022). Genomes of two giant viruses and their capacity in the infection cycles. (external link)
• Hasan Arsin; Anita-Elin Fedøy; Victoria Røyseth et al. (2020). Bringing deep-sea enzymes to light. (external link)
• Mikal Heldal; Svein Norland; Egil Severin Erichsen et al. (2005). Mg2+ plays an important role in marine bacteria. (external link)
• Ruth-Anne Sandaa; Jessica Louise Ray; Julia Endresen Storesund et al. (2016). Marine viral diversity in the Arctic - from surface to deep waters through the long polar night and day.. (external link)
• Elianne Sirnæs Egge; Wenche Eikrem; Vladyslava Hostyeva et al. (2012). Diversity and seasonal dynamics of haptophytes in outer Oslofjorden revealed by 454 pyrosequencing. (external link)

Research report

• Ruth-Anne Sandaa; Vigdis Lid Torsvik; J. Goksøyr (1994). Miljøeffekter ved utsetting av mikroorganismer. SFT, 93513. (external link)
• Ruth-Anne Sandaa; Vigdis Lid Torsvik; J. Goksøyr (1994). Miljøeffekter ved utsetting av mikroorganismer. Dir. for naturforvaltning, BTEK 69404. (external link)

Doctoral thesis (PhD)

• Julia Endresen Storesund; Ruth-Anne Sandaa (2016). Bacterial, archaeal and viral community structure in a deep Norwegian fjord. (external link)
• Ruth-Anne Sandaa (1994). Conjugal transfer of antibiotic resistance genes in marine sediments. (external link)
• Laila Brunvold; Ruth-Anne Sandaa (2010). Microbial ecology in the early life stages of intensively reared marine species. (external link)

Popular science article

• Ruth-Anne Sandaa (2003). Vennlige Virus. (external link)
• Ruth-Anne Sandaa; Thorolf Magnesen (2004). Produksjon av kamskjellyngel. Vekk med antibiotika og opp med overlevelsen. (external link)

Academic literature review

• Cátia Carreira; Christian Lonborg; Michael Kühl et al. (2020). Fungi and viruses as important players in microbial mats. (external link)
• Arnthór Aevarsson; Anna-Karina Kaczorowska; Björn Thor Adalsteinsson et al. (2021). Going to extremes - A metagenomic journey into the dark matter of life. (external link)
• Selina Våge; Gunnar Bratbak; Jorun Karin Egge et al. (2018). Simple models combining competition, defence and resource availability have broad implications in pelagic microbial food webs. (external link)

Encyclopedia entry

• Ruth-Anne Sandaa (2009). Viral pool, environmental. (external link)

Master’s thesis

• Øyvind Karlbom; Ruth-Anne Sandaa (2006). DNA characterization and phylogenetic analyses on species of pelagic Crustacea from the Mid-Atlantic ridge. (external link)

See a complete overview of publications in Cristin.

 

1.Sandaa, R.-A., V. Torsvik, J. Goksøyr. 1992. Transferable drug resistance in bacteria from fish-farm sediments. Can. J. Microbiol. 38:1061-1065.

2.Sandaa, R.-A. 1993. Transfer and maintenance of the plasmid RP4 in marine sediments. Microb. Releases. 2:115-119.

3.Enger, Ø., R.-A. Sandaa. 1994. Immunomagnetic beads as a tool in conjugation experiments. J. of Microb. Meth. 19:111-115.

4.Sandaa R.-A., and Ø. Enger. 1994. High frequency transfer of a broad host range plasmid indigenous to the fish pathogen Aeromonas salmonicida. Dis. Aquat. Org. 24:71-75.

5.Sandaa, R.-A., and Ø. Enger. 1994. Transfer of a naturally occurring plasmid in  Aeromonas salmonicida 718 in unsterile marine sediments. Appl. Environ. Microbiol. 60: 4234-4238.

6.Andersen, S.R., R.-A. Sandaa. 1994. Distribution of tetracycline resistance determinants among gram-negative bacteria isolated from polluted and unpolluted marine sediments. Appl. Environ. Microbiol. 60:908-912.

7.Sandaa, R-A., Ø. Enger, and V. Torsvik. 1998. Rapid method for fluorometric quantification of bacterial DNA in soil. Soil Biol. Biochem. 30:265-268.

8.Torsvik, V., F.L. Daae, R.-A. Sandaa, and L. Øvreås. 1998. Review. Novel Techniques for analysing microbial diversity in natural and pertutibed environments. J  Biotech 64:53-62

9.Chatzinotas A., R.-A. Sandaa, D. Hahn, W. Schönhuber, F.L. Daae, V. Torsvik, J. Zeyer, and R. Amann. 1998. Analysis of Broad-scale Differences in Microbial Community Compositions of Two Pristine Forest Soils. Syst. Appl. Microbiol. 21:579-587

10.  Sandaa, R-A., V. Torsvik, Ø. Enger, F.L. Daae, T. Castberg and D. Hahn. 1999. Analysis of bacterial communities in heavy metal contaminated soils at different levels of resolution. FEMS Microb. Ecol. 30:237-251.

11.  Sandaa, R-A., Ø. Enger, and V. Torsvik. 1999. Abundance of Archaea in Heavy Metal Contaminated Soils. Appl. Environ. Microbiol. 65:3293-3297

12.  Torsvik, V., F.L. Daae, R.-A. Sandaa and L. Øvreås. 2000. Molecular Biology and genetic diversity of microorganisms. In: Journey to diverse Microbial world: Adaptation to exotic environments. J. Seckbach (Ed.) Kluwer Academic Publishers. the Netherlands. pp 43-57.

13.  Sandaa, R.-A., V. Torsvik and Ø. Enger. 2001. Influence by long term heavy metal contamination on microbial communities in soil. Soil Biol. Biochem. 33:287-295.

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

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

16.  Smalla K., E. Krogerrecklenfort, H. Heuer, W. Dejonghe, E. Top, M. Osborn, J. Niewint, C. Tebbe, M. Barr, M. Bailey, A. Greated, C. Thomas, S. Turner, P. Young, D. Nikolakopoulou, A. Karagouni, A. Wolters, J. D. van Elsas, K. Drønen, R. Sandaa, S. Borin, J. Brabhu, E. Grohmann and P. Sobecky. 2000. PCR-based detection of mobile genetic elements in total community DNA. Microbiol. 146:1256-1257

17.  Sandaa, R.-A., M. Heldal, T. Castberg, R. Thyrhaug and G. Bratbak. 2001. Isolation and characterization of two viruses with large genom size infecting Chrysochromulina ericina (Prymnesiophyceae) and Pyramimonas orientalis (Prasinophyceae). Virol. 290:272-280

18.  Castberg, T, R. Thyrhaug,  A. Larsen, R-A.  Sandaa, M. Heldal, G. Bratbak. 2002. Isolation and characterization of virus infecting Emiliania huxleyi (Haptophyceae). Phycol. 38:767-774

19.  Øvreås, L., D. Bourne, R-A. Sandaa, E. O. Casamayor, S. Benlloch, V. Goddard, G. Smerdon, M. Heldal, T. F. Thingstad. 2003. Response of bacterial and viral communities to nutrient manipulations in seawater mesocosms. Aquat. Microb. Ecol. 31: 109–121

20.  Sandaa R-A., T. Magnesen, L. Torkildsen, Ø. Bergh. 2003. Characterisation of bacterial communities associated with early life stages of cultured Great Scallop, Pecten maximus using Denaturing Gradient Gel Electrophoresis (DGGE). Syst. Appl. Microbiol. 26:302-311

21.  Sandaa, R-A., E. Skjoldal, G. Bratbak. 2003. Virioplankton community structure along a salinity gradient in a solar saltern. Extremophiles. 7:347-351,

22.  Kurabachew M.D., Ø. Enger, Sandaa, R-A., B. Bjorvatn. 2003. Sequence analysis in the 23SDNA region of Mycobacterium tuberculosis and related species. J. Microbiol. Methods. 54:373-380

23.  Kurabachew M.D., Sandaa, R-A., Ø. Enger, B. Bjorvatn. 2003. Amplified Ribosomal DNA Restriction Analysis (ARDRA) in the differentiation of related species of Mycobacteria. J. Microbiol. Methods. 55: 83-90.

24.  Larsen, A., G.A .Fonnes, R-A. Sandaa, T. Castberg, R .Thyrhaug, S.E. Erga, S. Jacquet, and G. Bratbak. 2004. Spring phytoplankton bloom in Norwegian coastal waters: Microbial community dynamics, succession and diversity. Limn. Oceanog.  49:180-190

25.  Brussaard, C.P.D, R-A. Sandaa, G. Bratbak. 2004. The discovery of a novel algal virus type infection of the phytoplankter Micromonas pusilla by a double stranded RNA reovirus. Virol. 319:280-291

26.  Kurabachew M.D., Ø. Enger, R-A. Sandaa, R.  Skuce  and B. Bjorvatn. 2004. Multiplex PCR assay for the detection of mycobacteria and species identification of Mycobacterium bovis and Mycobacterium tuberculosis. Diagn. Microbiol. Infect. Dis. 49:99-104.

27.  Sandaa R-A., A. Larsen. 2006. Seasonal variations in viral-host populations in Norwegian coastal waters: Focusing on the cyanophage community infecting marine Synechococcus species. Appl. Environ. Microbiol. 72:4610-4618.

28.  Brunvold, L, R-A. Sandaa, H. Bleie, D. Herke, A.B. Olsen,  H. Mikkelsen, E. Welde, A. Nerland, and Ø. Bergh. 2007.  Characterisation of bacterial communities associated with intensively reared cod (Gadus morhua) larvae using Denaturing Gradient Gel Electrophoresis (DGGE).  Aquaculture, 272: 319-327

29.  Sandaa R-A., M. Clokie, N. Mann. 2008. Photosynthetic genes in viral populations within a huge genomic size range, isolated from Norwegian coastal waters.  FEMS Microb. Ecol. 63:2-11

30.  Sandaa, R-A., L. Brunvold,  T. Magnesen, and Ø. Bergh. 2008.  Monitoring opportunistic bacteria in a hatchery for great scallop, Pecten maximus by means of Denaturing Gradient Gel Elecrophoresis (DGGE). Aquaculture 276:14–21.

31.  Monier A., J. Borggaard Larsen, R-A. Sandaa, G. Bratbak, J-M. Claverie, H. Ogata. 2008. Marine mimivirus relatives are probably large algal viruses. Virol. J. 5:12

32.  Larsen, J.B., A. Larsen, R. Thyrhaug, G. Bratbak, and R-A. Sandaa. 2008. Marine viral populations detected during a nutrient induced phytoplankton bloom at elevated pCO2 levels. Biogeosciences 5: 523–533

33.  Larsen, J.B. A. Larsen, G. Bratbak, and R.-A. Sandaa. 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.

34.     Sandaa, R-A. 2008. Review. Burden or Benefit-viral –host interaction in the marine environment. Review in Research in Microbiology, 159, 374-381.

35.     Thingstad TF, 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 food web response to organic carbon enrichment in anarctic pelagic ecosystem.  Nature,  455:387-390

36.  Sandaa, R-A.  2009. Viral pool, environmental. In: Encyclopedia in Microbiology, third edition, Ed: Moselio Schaechter, Section: Environmental Microbiology and Ecology.  pp 553-567. Elsevier Ltd.   

37.  Sandaa, R-A., S. Short, D. Schröder.  2009, Fingerprinting aquatic virus communities. In: Methods in Aquatic Viral Ecology.  American Society of Limnology and Oceanography, Inc.,   Chapter 2, pp 9–18.

38.  Sandaa, R.-A., L. Gomez-Consarnau, J. Pinhassi, L. Riemann, A. Malits, M. Weinbauer, P.A. Gasol,  and T. F. Thingstad. 2009. Viruses control of bacterial biodiversity - Linkages between viral and bacterial community structure in a nutrient enriched mesocosm experiment. Environmental Microbiology, 11:2585-2595.

39.  Birte Töpper, Aud Larsen, Tron Frede Thingstad, Runar Thyrhaug & Ruth-Anne Sandaa. 2010.Dynamics in bacterial community composition during an Arctic phytoplankton mesocosm bloom. Polar Biology, 33:1557–1565.

40.  Fahlgren, C., Bratbak, G., Sandaa, R-A., Thyrhaug, R., Zweifel, U.L. 2010. Diversity of airborne bacteria in samples collected by use of different devices for aerosol collection. Aerobiologia 1:14.

41.  van der Meeren T, Brunvold, L., Sandaa, R-A., Bergh, Ø., Castberg, T.,Thyrhaug, R., Mangor-Jensen, A.  2011. Water quality and microbial community structure in juvenile Atlantic cod (Gadus morhua L.) cultures. Aquaculture International, 316:111-120.

42.  Ogata, H., Ray, J., Toyoda, K., Sandaa, R.-A, Nagasaki K, Bratbak, G.,  Claverie, J.M. 2011. Girus-encoded MutS subfamilies abundant in the marine environment. ISME journal, 1-9.

43.  Goldsmith, Crosti, Varsani, McDaniel, Dwivedi, Carlson, Suttle, Weinbauer, Sandaa, Breitbart.2011.  Pho Regulon Genes in Phage: Development of a Novel Signature Gene for Assessing Marine Phage Diversity. Appl. Microb. Ecol,77:7730-7739

44.  Heldal, M, Norland, S, Erichsen, E.S., Sandaa, R.-A.Larsen, A., Thingstad, F. and Bratbak, G. 2011. Mg2+ as an indicator of nutritional status in marine bacteria, ISME Journal, 1–7.

45.  Modha, S. Ray, J., Dondrup, M., Steen, I. H., Sandaa, R.-A. and Clokie, M.. Finding the needle in the  metagenomic viral haystack -  Micro-metagenome analysis captures a snapshot of the evolution of a bacteriophage armoire, submitted to PLoS One

• VirVar: Uncovering key players for regulation of phytoplankton function and structure: lessons to be learned from algal virus-haptophyte coexistence, NFR
• Arven etter Nansen (The Nansen Legacy), NFR
• Virus-X, “Viral metagenomics for innovation value” , EU project Horizon 2020-Biotech
• VIROVAC: Filter-feeding mesozooplankton as uncharted accomplices in marine virus ecology. NFR