Blar i NTNU Open på forfatter "Sletta, Håvard"
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Acid preservation of cultivated brown algae Saccharina latissima and Alaria esculenta and characterization of extracted alginate and cellulose
Nøkling-Eide, Katharina; Tan, Fangchang; Wang, Shennan; Zhou, Qi; Gravdahl, Mina; Langeng, Anne-Mari; Bulone, Vincent; Aachmann, Finn Lillelund; Sletta, Håvard; Arlov, Øystein (Peer reviewed; Journal article, 2023)Cultivated brown algae represent an important potential source of carbohydrate polymers for packaging and other biobased materials. However, their exploitation is currently limited by a short harvest season and a lack of ... -
Acid preservation of Laminaria hyperborea with formic and acetic acid and its effects on alginate
Nøkling-Eide, Katharina; Aachmann, Finn Lillelund; Josefsen, Kjell Domaas; Szczybelski Ciordia, Ariadna Sabina; Sletta, Håvard; Arlov, Øystein (Journal article; Peer reviewed, 2024)Each year, 150,000 tons of Laminaria hyperborea is harvested commercially for alginate production in Norway. Traditionally, formalin has been an attractive preservative in the industry because it inhibits microbial growth ... -
Assembly and application of genome-scale metabolic models to study Streptomyces coelicolor and Prochlorococcus
Sulheim, Snorre (Doctoral theses at NTNU;2021:96, Doctoral thesis, 2021)Summary: Metabolism is the set of all chemical reactions responsible for the conversion of nutrients into the energy and cellular building blocks required for growth and cellular maintenance in a living organism. Because ... -
An assessment of physical and chemical conditions in alginate extraction from two cultivated brown algal species in Norway: Alaria esculenta and Saccharina latissima
Nøkling-Eide, Katharina; Langeng, Anne-Mari; Åslund, Karl Olof Andreas; Aachmann, Finn Lillelund; Sletta, Håvard; Arlov, Øystein (Peer reviewed; Journal article, 2023)Alginates are linear anionic polysaccharides originating from brown algae. Their properties target several application areas in in food-, technical- and pharmaceutical industries, and thus they are highly valued. Norway ... -
Biosynthesis and Function of Long Guluronic Acid-Blocks in Alginate Produced by Azotobacter vinelandii
Aarstad, Olav Andreas; Stanisci, Annalucia; Sætrom, Gerd Inger; Tøndervik, Anne; Sletta, Håvard; Aachmann, Finn Lillelund; Skjåk-Bræk, Gudmund (Journal article; Peer reviewed, 2019)With the present accessibility of algal raw material, microbial alginates as a source for strong gelling material are evaluated as an alternative for advanced applications. Recently, we have shown that alginate from algal ... -
Butanol production from lignocellulosic sugars by Clostridium beijerinckii in microbioreactors
Birgen, Cansu; Degnes, Kristin Fløgstad; Markussen, Sidsel; Wentzel, Alexander; Sletta, Håvard (Peer reviewed; Journal article, 2021)Butanol (n-butanol) has been gaining attention as a renewable energy carrier and an alternative biofuel with superior properties to the most widely used ethanol. We performed 48 anaerobic fermentations simultaneously with ... -
Cellulose Nanofibrils/Alginates Double-Network Composites: Effects of Interfibrillar Interaction and G/M Ratio of Alginates on Mechanical Performance
Zha, Li; Aachmann, Finn Lillelund; Sletta, Håvard; Arlov, Øystein; Zhou, Qi (Journal article; Peer reviewed, 2024)Interfibrillar phases and bonding in cellulose nanofibril (CNF)-based composites are crucial for materials performances. In this study, we investigated the influence of CNF surface characteristics, the guluronic acid/mannuronic ... -
Chitosan as a wound dressing starting material: antimicrobial Properties and mode of action
Matica, Mariana Adina; Aachmann, Finn Lillelund; Tøndervik, Anne; Sletta, Håvard; Ostafe, Vasile (Journal article; Peer reviewed, 2019)Fighting bacterial resistance is one of the concerns in modern days, as antibiotics remain the main resource of bacterial control. Data shows that for every antibiotic developed, there is a microorganism that becomes ... -
Cytotoxicity of poly(Alkyl cyanoacrylate) nanoparticles
Sulheim, Einar; Iversen, Tore Geir; To, Vu; Klinkenberg, Geir; Sletta, Håvard; Schmid, Ruth; Hatletveit, Anne Rein; Wågbø, Ane Marit; Sundan, Anders; Skotland, Tore; Sandvig, Kirsten; Mørch, Ýrr Asbjørg (Journal article; Peer reviewed, 2017)Although nanotoxicology has become a large research field, assessment of cytotoxicity is often reduced to analysis of one cell line only. Cytotoxicity of nanoparticles is complex and should, preferentially, be evaluated ... -
Development of Expression Systems and Cultivation Conditions for Production of Heterologous Proteins in Pseudomonas
Haukaas, Tonje Husby (Master thesis, 2011)This study has been part of the project Development of versatile bacterial expression systems for use in recombinant protein production, metabolic engineering, and systems biology , a collaboration between NTNU, SINTEF ... -
Exploiting mannuronan C-5 epimerases in commercial alginate production
Tøndervik, Anne; Aarstad, Olav Andreas; Aune, Randi; Maleki, Susan; Rye, Philip D; Dessen, Arne; Skjåk-Bræk, Gudmund; Sletta, Håvard (Peer reviewed; Journal article, 2020)Alginates are one of the major polysaccharide constituents of marine brown algae in commercial manufacturing. However, the content and composition of alginates differ according to the distinct parts of these macroalgae and ... -
Fluxome study of Pseudomonas fluorescens reveals major reorganisation of carbon flux through central metabolic pathways in response to inactivation of the anti-sigma factor MucA
Lien, Stina Katrine; Niedenführ, Sebastian; Sletta, Håvard; Nöh, Katharina; Bruheim, Per (Journal article; Peer reviewed, 2015)Background: The bacterium Pseudomonas fluorescens switches to an alginate-producing phenotype when the pleiotropic anti-sigma factor MucA is inactivated. The inactivation is accompanied by an increased biomass yield on ... -
Hvordan styrke SFI-enes bidrag til innovasjon?
Henriksen, Partow Pakdel; Nisja, Ragnhild; Størkersen, Kristine Vedal; Wærnes, Aud Nina; Sletta, Håvard; Haug, Kaja Kristine; Måsøy, Svein-Erik; Langseth, Magnus; Henriksen, Ottar; Skjølsvik, Kjell Olav (Research report, 2023) -
Identification of a Pivotal Residue for Determining the Block Structure-Forming Properties of Alginate C-5 Epimerases
Stanisci, Annalucia; Tøndervik, Anne; Gaardløs, Margrethe; Lervik, Anders; Skjåk-Bræk, Gudmund; Sletta, Håvard; Aachmann, Finn Lillelund (Peer reviewed; Journal article, 2020)Alginate is a linear copolymer composed of 1→4 linked β-d-mannuronic acid (M) and its epimer α-l-guluronic acid (G). The polysaccharide is first produced as homopolymeric mannuronan and subsequently, at the polymer level, ... -
Identification of genes affecting alginate biosynthesis in Pseudomonas fluorescens by screening a transposon insertion library.
Ertesvåg, Helga; Sletta, Håvard; Senneset, Mona; Sun, Yi-Qian; Klinkenberg, Geir; Konradsen, Therese Aursand; Ellingsen, Trond E; Valla, Svein (Journal article; Peer reviewed, 2017)BACKGROUND: Polysaccharides often are necessary components of bacterial biofilms and capsules. Production of these biopolymers constitutes a drain on key components in the central carbon metabolism, but so far little is ... -
Identification of Regulatory Genes and Metabolic Processes Important for Alginate Biosynthesis in Azotobacter vinelandii by Screening of a Transposon Insertion Mutant Library
Mærk, Mali; Jakobsen, Øyvind Mejdell; Sletta, Håvard; Klinkenberg, Geir; Tøndervik, Anne; Ellingsen, Trond Erling; Valla, Svein; Ertesvåg, Helga (Journal article; Peer reviewed, 2020)Azotobacter vinelandii produces the biopolymer alginate, which has a wide range of industrial and pharmaceutical applications. A random transposon insertion mutant library was constructed from A. vinelandii ATCC12518Tc in ... -
In-process epimerisation of alginates from Saccharina latissima, Alaria esculenta and Laminaria hyperborea
Nøkling-Eide, Katharina; Aachmann, Finn Lillelund; Tøndervik, Anne; Arlov, Øystein; Sletta, Håvard (Journal article; Peer reviewed, 2024)Alginates are valued in many industries, due to their versatile properties. These polysaccharides originate from brown algae (Phaeophyceae) and some bacteria of the Azotobacter and Pseudomonas genera, consisting of 1 → 4 ... -
Intracellular metabolite pool changes in response to nutrient depletion induced metabolic switching in Streptomyces coelicolor
Wentzel, Alexander; Sletta, Håvard; Wellington, E.M.H.; Ellingsen, Trond Erling; Bruheim, Per (Journal article; Peer reviewed, 2012)Abstract: A metabolite profiling study of the antibiotic producing bacterium Streptomyces coelicolor A3(2) has been performed. The aim of this study was to monitor intracellular metabolite pool changes occurring as strains ... -
Mannuronan C-5 Epimerases Suited for Tailoring of Specific Alginate Structures Obtained by High-Throughput Screening of an Epimerase Mutant Library
Tøndervik, Anne; Klinkenberg, Geir; Aachmann, Finn Lillelund; Svanem, Britt Iren Glærum; Ertesvåg, Helga; Ellingsen, Trond Erling; Valla, Svein; Skjåk-Bræk, Gudmund; Sletta, Håvard (Journal article; Peer reviewed, 2013)The polysaccharide alginate is produced by brown algae and some bacteria and is composed of the two monomers, β-d-mannuronic acid (M) and α-l-guluronic acid (G). The distribution and composition of M/G are important for ... -
Mannuronate C-5 epimerases and their use in alginate modification
Beenfeldt Petersen, Agnes; Tøndervik, Anne; Gaardløs, Margrethe; Ertesvåg, Helga; Sletta, Håvard; Aachmann, Finn Lillelund (Journal article; Peer reviewed, 2023)Alginate is a polysaccharide consisting of β-D-mannuronate (M) and α-L-guluronate (G) produced by brown algae and some bacterial species. Alginate has a wide range of industrial and pharmaceutical applications, owing mainly ...