Browsing NTNU Open by Author "Vadstein, Olav"
Now showing items 1-20 of 115
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A study of the interactions and dynamics of microbial communties
Pettersen, Jakob Peder (Master thesis, 2019)De seneste årene har strukturen, sammensetningen og interaksjonene i mikrobielle samfunn vært et hett tema i de vitenskapelig miljøene. En rekke næringer som havbruk, vannbehandling og helse har mye å tjene dersom en utvidet ... -
Anaerobic digestion of pig manure supernatant at high ammonia concentrations characterized by high abundances of Methanosaeta and non-euryarchaeotal archaea
Nordgård, Anna Synnøve Røstad; Bergland, Wenche Hennie; Vadstein, Olav; Mironov, Vladimir; Bakke, Rune; Østgaard, Kjetill; Bakke, Ingrid (Journal article; Peer reviewed, 2017)We examined the effect of ammonium and temperature on methane production in high rate upflow anaerobic sludge bed reactors treating pig manure supernatant. We operated four reactors at two ammonium concentrations (‘low’ ... -
Analytical challenges and characterization of skin and gut microbiota of Atlantic salmon fry in a commercial smolt production facility.
Udoye, Chinweike (Master thesis, 2018)Although the Atlantic salmon is an economically important specie, little information exist on the composition of its gut and skin microbiota during early lifestages. Fish microbiota play an essential role in health of fish ... -
Aquaculture rearing systems induce no legacy effects in Atlantic cod larvae or their rearing water bacterial communities
Gundersen, Madeleine S.; Vadstein, Olav; De Schryver, Peter; Attramadal, Kari (Peer reviewed; Journal article, 2022)The microbial rearing quality influences the survival of marine larvae. Microbially matured water treatment systems (MMS) provide a more favourable rearing water microbiome than flow-through systems (FTS). It has previously ... -
Bacterial community assembly in Atlantic cod larvae (Gadus morhua): Contributions of ecological processes and metacommunity structure
Vestrum, Ragnhild Inderberg; Attramadal, Kari; Vadstein, Olav; Gundersen, Madeleine Stenshorne; Bakke, Ingrid (Peer reviewed; Journal article, 2020)Many studies demonstrate the importance of the commensal microbiomes to animal health and development. However, the initial community assembly process is poorly understood. It is unclear to what extent the hosts select for ... -
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 (Journal article; Peer reviewed, 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 community structures and dynamics in host and built environments of Arctic charr (Salvelinus alpinus) aquacultured in RAS and FTS
Stubban Berg, Malin (Master thesis, 2022)Resirkulerende akvakultursystemer (RAS) øker i populæritet for produksjon av laksefisk. Vannet resirkuleres i et RAS, sammenlignet med gjennomstrømningssystemer (FTS) hvor det er behov for konstant tilførsel av nytt vann. ... -
Biodiesel fra mikroalger: Betydning av næringssaltbegrensning for syntese og utbytte av lipider og karbohydrater i kiselalger (diatomeer).
Heien, Hilde Rau (Master thesis, 2011)Målet med masteroppgaven var å vurdere effekten av ulike fortynningsrater ved dyrking av Phaeodactylum tricornutum og Chaetoceros muelleri i silikat- og nitrogenredusert medium, med fokus på vekst (biomasse og celletall) ... -
Biofilms remember: Osmotic stress priming as a microbial management strategy for improving salinity acclimation in nitrifying biofilms
Navada, Sharada; Vadstein, Olav; Gaumet, Frederic; Tveten, Ann-Kristin; Spanu, Claudia; Mikkelsen, Øyvind; Kolarevic, Jelena (Peer reviewed; Journal article, 2020)With increasing freshwater scarcity and greater use of seawater,fluctuating salinities are becomingcommon in water treatment systems. This can be challenging for salinity-sensitive processes like nitri-fication, especially ... -
Biosynthesis and characterization of Ti-doped silica-based Nanostructures formed by the Diatoms Pinnularia sp. and Coscinodiscus wailesii
Skolem, Lotte Maria Beate (Master thesis, 2011)The metabolic insertion of titanium into the biosilica frustules of the pennate diatom Pinnularia sp. and the centric diatom Coscinodiscus wailesii was explored in the present study. A total of five titanium incorporation ... -
Bruk av selektiv dyrkningsstrategi for å øke spesifikt lipidinnhold i mikroalger, for produksjon av biodiesel
Sæther, Ruben Mathias (Master thesis, 2013)Mineralolje er en begrenset og ikke-fornybar resurs, og drivstoff produsert fra mineralolje har flere negative effekter på miljøet. Dette gjør at det på lang sikt vil være nødvendig med en alternativ energikilde som er ... -
Capacity of a flow-through biofilter system to secure K-selection and microbial stability in the out-flowing water
Solberg, Erlend Hafsten (Master thesis, 2018)Water treatment and design of aquaculture systems are typically focused on optimising physicochemical water quality and efforts to maintain bacteria numbers low. High bacteria numbers are not necessarily problematic for ... -
Carbon sequestration by microbial carbon pump with production of recalcitrant dissolved organic matter in different marine environments
Avarachen, Mathew Kuttivadakkethil (Doctoral theses at NTNU;2023:331, Doctoral thesis, 2023)The carbon dioxide in the atmosphere is causing global warming and other associated climate change events. The world countries have pledged to cut down the carbon dioxide emissions to counter act these climate change ... -
Cell Wall Biomineralization in the Centric Diatom Thalassiosira pseudonana: Investigation of the Putative Role of Silicanin Tp23191 and the Impact of Microfilaments and Microtubules
Årdal, Vilde (Master thesis, 2020)Kiselalgar inkorporerar kiseldioksid, betre kjent som silika (SiO2), i celleveggen, frustulen, i eit karakteristisk og artspesifikt mønster. Denne silika-strukturen er av høg styrke, og nettopp difor er det fordelaktig å ... -
Changes in microbial water quality in RAS following altered feed loading
Rojas-Tirado, Paula; Pedersen, Per Bovbjerg; Vadstein, Olav; Pedersen, Lars-Flemming (Journal article; Peer reviewed, 2018)Intensive recirculating aquaculture systems (RAS) with its hyper-eutrophic water offer ideal conditions for bacterial growth, abundance and activity, potentially affecting fish and system performance. Feed composition and ... -
Changes in the microbial community of an anammox consortium during adaptation to marine conditions revealed by 454 pyrosequencing
Gonzalez Silva, Blanca Magdalena; Rønning, Are J.; Andreassen, Ingrid Krogrud; Bakke, Ingrid; Cervantes, Francisco J.; Østgaard, Kjetill; Vadstein, Olav (Journal article; Peer reviewed, 2017)The anammox activity of a freshwater anammox consortium was strongly inhibited at low-salinity level. Stepwise adaptation from 0 to 3 g NaCl L−1 took 153 days. Further adaptation to high-salinity concentration (from 3 to ... -
Commensal and opportunistic bacteria present in the microbiota in atlantic cod (Gadus morhua) larvae differentially alter the hosts’ innate immune responses
Vestrum, Ragnhild Inderberg; Forberg, Torunn; Luef, Birgit; Bakke, Ingrid; Winge, Per; Olsen, Yngvar; Vadstein, Olav (Journal article; Peer reviewed, 2022)The roles of host-associated bacteria have gained attention lately, and we now recognise that the microbiota is essential in processes such as digestion, development of the immune system and gut function. In this study, ... -
Comparative transcriptomics reveals domestication‐associated features of Atlantic salmon lipid metabolism
Jin, Yang; Olsen, Rolf Erik; Harvey, Thomas Nelson; Østensen, Mari-Ann; Li, Keshuai; Santi, Nina; Vadstein, Olav; Bones, Atle M.; Vik, Jon Olav; Sandve, Simen Rød; Olsen, Yngvar (Peer reviewed; Journal article, 2020)Domestication of animals imposes strong targeted selection for desired traits but can also result in unintended selection due to new domestic environments. Atlantic salmon was domesticated in the 1970s and has subsequently ... -
A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish
Fossmark, Ragnhild Olsen; Attramadal, Kari; Kristian, Nordøy; Østerhus, Stein Wold; Vadstein, Olav (Peer reviewed; Journal article, 2021)The land-based production phase in Norwegian Atlantic salmon farming has the past years been extended to include post-smolt for an increasing number of farmers. Post-smolt production can involve introduction of brackish/seawater ... -
Correlation between microbiota and growth in Mangrove Killifish (Kryptolebias marmoratus) and Atlantic cod (Gadus morhua)
Forberg, Torunn; Sjulstad, Eli Bjørnø; Bakke, Ingrid; Olsen, Yngvar; Hagiwara, Atsushi; Sakakura, Yoshitaka; Vadstein, Olav (Journal article; Peer reviewed, 2016)The vertebrate gut is host to large communities of bacteria, and one of the beneficial contributions of this commensal gut microbiota is the increased nutritional gain from feed components that the host cannot degrade on ...