Blar i Bergen Open Research Archive på forfatter "Roalkvam, Irene"
-
Assessment of the carbon monoxide metabolism of the hyperthermophilic sulfate-reducing archaeon Archaeoglobus fulgidus VC-16 by comparative transcriptome analyses
Hocking, William Peter; Roalkvam, Irene; Magnussen, Carina; Stokke, Runar; Steen, Ida Helene (Peer reviewed; Journal article, 2015)The hyperthermophilic, sulfate-reducing archaeon, Archaeoglobus fulgidus, utilizes CO as an energy source and it is resistant to the toxic effects of high CO concentrations. Herein, transcription profiles were obtained ... -
A case study of biofilter activation and microbial nitrification in a marine recirculation aquaculture system for rearing Atlantic salmon (Salmo salar L.)
Roalkvam, Irene; Drønen, Karine; Dahle, Håkon; Wergeland, Heidrun Inger (Peer reviewed; Journal article, 2020-09)Marine recirculation aquaculture system (RAS) is a prominent technology within fish farming. However, the nitrifying bacteria in the biofilter have low growth rates, which can make the biofilter activation a long and ... -
Diversity, stratification and in situ metabolism of anaerobic methanotrophic archaea in Nyegga cold seeps
Roalkvam, Irene (Doctoral thesis, 2012-06-08)Anaerobic methanotrophic Archaea (ANME) have considerable importance in a global environmental context as they are considered the major biological sink for methane due to their ubiquitous distribution in anaerobic ... -
Identification of key components in the energy metabolism of Archaeoglobus fulgidus by transcriptome analyses
Hocking, William Peter; Stokke, Runar; Roalkvam, Irene; Steen, Ida Helene (Peer reviewed; Journal article, 2014-03-11)Energy conservation via the pathway of dissimilatory sulfate reduction is present in a diverse group of prokaryotes, but is most comprehensively studied in Deltaproteobacteria. In this study, whole-genome microarray analyses ... -
Microbial colonization and community stability in a marine post-smolt RAS inoculated with a commercial starter culture
Drønen, Asbjørg Karine; Roalkvam, Irene; Dahle, Håkon; Nilsen, Hanne Katrine; Olsen, Anne Berit; Wergeland, Heidrun Inger (Journal article; Peer reviewed, 2021)The performance of a commercial starter culture was investigated in a new marine post-smolt RAS, analyzing the microbial communities of 100 samples collected monthly over a year from biofilter biofilm carriers, tank wall ... -
Microbial Communities in a Flow-Through Fish Farm for Lumpfish (Cyclopterus lumpus L.) During Healthy Rearing Conditions
Roalkvam, Irene; Drønen, Karine; Dahle, Håkon; Wergeland, Heidrun Inger (Peer reviewed; Journal article, 2019-07-12)Lumpfish can efficiently remove sea lice from Atlantic salmon in net-pens, and production of lumpfish in closed fish farms is a new, fast developing industry in Norway. However, periodic outbreaks of bacterial diseases in ... -
Presence and habitats of bacterial fish pathogen relatives in a marine salmon post-smolt RAS
Drønen, Asbjørg Karine; Roalkvam, Irene; Nilsen, Hanne Katrine; Olsen, Anne Berit; Dahle, Håkon; Wergeland, Heidrun Inger (Journal article; Peer reviewed, 2022)Recycling aquaculture system (RAS) requires well-functioning microbial communities to support fish welfare and to minimize the risk of spreading diseases. In this study of a marine post-smolt RAS we searched for groups of ... -
Profundibacter amoris gen. nov., sp. nov., a new member of the Roseobacter clade isolated from Loki's Castle Vent Field on the Arctic Mid-Ocean Ridge
Le Moine Bauer, Sven; Sjøberg, Andreas Gilje; L´Haridon, Stephane; Stokke, Runar; Roalkvam, Irene; Steen, Ida Helene; Dahle, Håkon (Peer reviewed; Journal article, 2019)A bacterial strain, designated BAR1T, was isolated from a microbial mat growing on the surface of a barite chimney at the Loki’s Castle Vent Field, at a depth of 2216 m. Cells of strain BAR1T were rod-shaped, Gram-reacti ...