Blar i NTNU Open på forfatter "Ertesvåg, Helga"
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Identification of a New Phosphatase Enzyme Potentially Involved in the Sugar Phosphate Stress Response in Pseudomonas fluorescens
Maleki, Susan; Hrudikova, Radka; Zotchev, Sergey; Ertesvåg, Helga (Journal article; Peer reviewed, 2017)The alginate-producing bacterium Pseudomonas fluorescens utilizes the Entner-Doudoroff (ED) and pentose phosphate (PP) pathways to metabolize fructose, since the upper part of its Embden-Meyerhof-Parnas pathway is defective. ... -
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 ... -
Investigation of Encystment and Characterization of Exopolysaccharides in Azotobacter Species
Solem, Anita (Master thesis, 2022)Bakterier tilhørende slekten Azotobacter kan danne en hvilene celletype, kalt cyster. Cyster er mer motstandsdyktige enn vegetative celler mot skadelige effekter som tørking, stråling og sonikering. En forståelse av hvilke ... -
Karakterisering av gener som påvirker biosyntesen av alginat i Azotobacter vinelandii
Haugsnes, Margit Dagsdatter (Master thesis, 2012)For å undersøke faktorer som innvirker på alginat-produksjonen til Azotobacter vinelandii har det blitt laget et mutant-bibliotek med stammen A. vinelandii ATCC 12518 som utgangspunkt. Etter screeningsforsøk med henblikk ... -
Karakterisering av gener som påvirker biosyntesen av alginat i Pseudomonas fluorescens
Selsaas, Eirik (Master thesis, 2011)Pseudomonas fluorescens har evne til å produsere store store mengder alginat. Tidligere er det laget en stamme, P. fluorescens SBW25 MS1 ΔalgC::TnKb61, hvor algD-operonet og algC er satt under kontroll av Pm-promotor. Dette ... -
Karakterisering av promotorsystemene AntR-pAnt og RhaSR-pRha for Pseudomonas fluorescens og effekten av antranilat på alginatproduksjonen
Wesche, Andreas Fossland (Master thesis, 2024)Biopolymeren alginat har flere egenskaper som gjør den egnet til bruk i flere forskjellige industrier. Alginat består av to monomerer, mannuronsyre og guluronsyre. Det er sammensetningen av disse bestanddelene som bestemmer ... -
Konstruksjon av vektorer for et CRISPR-Cas9 muteringssystem for Azotobacter vinelandii
Dahl, Marie Duus (Master thesis, 2019)Azotobacter vinelandii er en alginatproduserende bakterie med en viss industriell interesse. Alginat er en biopolymer benyttet i mange industrielle felt på grunn av dens geldannende egenskap. Bakteriell alginat har en annen ... -
Lipid and DHA-production in Aurantiochytrium sp. – Responses to nitrogen starvation and oxygen limitation revealed by analyses of production kinetics and global transcriptomes
Heggeset, Tonje Marita Bjerkan; Ertesvåg, Helga; Liu, Bin; Ellingsen, Trond Erling; Vadstein, Olav; Aasen, Inga Marie (Journal article; Peer reviewed, 2019)Thraustochytrids of the genera Schizochytrium and Aurantiochytrium accumulate oils rich in the essential, marine n3 fatty acid docosahexaenoic acid (DHA). DHA production in Aurantiochytrium sp T66 was studied with the aim ... -
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 ... -
Mapping global effects of the anti-sigma factor MucA in Pseudomonas fluorescens SBW25 through genome-scale metabolic modeling
Borgos, Sven Even F.; Bordel, Sergio; Sletta, Håvard; Ertesvåg, Helga; Jakobsen, Øyvind Mejdell; Bruheim, Per; Ellingsen, Trond Erling; Nielsen, Jens; Valla, Svein (Journal article; Peer reviewed, 2013)Background: Alginate is an industrially important polysaccharide, currently produced commercially by harvesting of marine brown sea-weeds. The polymer is also synthesized as an exo-polysaccharide by bacteria belonging to ... -
Marinobacter algicola - en ny alginatprodusent?
Heddeland Instefjord, Kamilla (Master thesis, 2013)Alginat er et polysakkarid bredt utnyttet i industrien, og består av beta-D-mannuronsyre (M) og alfa-L-guluronsyre (G). Disse monomerene er gruppert sammen i blokker av M, G eller MG. Under biosyntesen av alginat hos ... -
Method Development Progress in Genetic Engineering of Thraustochytrids
Rau, E-Ming; Ertesvåg, Helga (Peer reviewed; Journal article, 2021)Thraustochytrids are unicellular, heterotrophic marine eukaryotes. Some species are known to store surplus carbon as intracellular lipids, and these also contain the long-chain polyunsaturated fatty acid docosahexaenoic ... -
A non-canonical Δ9-desaturase synthesizing palmitoleic acid identified in the thraustochytrid Aurantiochytrium sp. T66.
Rau, E-Ming; Aasen, Inga Marie; Ertesvåg, Helga (Journal article; Peer reviewed, 2021)Thraustochytrids are oleaginous marine eukaryotic microbes currently used to produce the essential omega-3 fatty acid docosahexaenoic acid (DHA, C22:6 n-3). To improve the production of this essential fatty acid by strain ... -
Overexpression of two new acyl-CoA:diacylglycerol acyltransferase 2-like acyl-CoA:sterol acyltransferases enhanced squalene accumulation in Aurantiochytrium limacinum
Rau, E-Ming; Bartosova, Zdenka; Kristiansen, Kåre Andre; Aasen, Inga Marie; Bruheim, Per; Ertesvåg, Helga (Peer reviewed; Journal article, 2022)Thraustochytrids are heterotrophic marine eukaryotes known to accumulate large amounts of triacylglycerols, and they also synthesize terpenoids like carotenoids and squalene, which all have an increasing market demand. ... -
Produksjon og transport av alkylresorcinol i Azotobacter vinelandii
Gresholt, Ole Andreas (Master thesis, 2014)A. vinelandii er kjent for sin evne til å danne cyster ved mangel på en tilstrekkelig næringskilde. Under cystedannelsen blir mange av fosfolipidene i yttermembranen erstattet med alkylresorcinoler og alkylpyroner. Et ... -
Regulation of alginate biosynthesis in Azotobacter vinelandii
Sharma, Junu (Master thesis, 2014)Alginate is a linear exopolysaccharide composed of various amount of (1-4) linked β-D mannuronic acid and its C5 epimer α-L-guluronic acid. Alginate is synthesized by two bacterial genera Azotobacter and Pseudomonas. ... -
Reporter genes for relative quantification of promoter strength and c-di-GMP in Pseudomonas fluorescens.
Vold, Susanna (Master thesis, 2021)Alginat er en industrielt viktig polymer som består av de to monomerene mannuronsyre og guluronsyre. Denne polymeren kan brukes til å transportere legemidler inn i kroppen, sårheling og muligens i vevsregenerering. Alginat ... -
RpoS controls the expression and the transport of the AlgE1-7 epimerases in Azotobacter vinelandii
Moreno, Soledad; Ertesvåg, Helga; Valla, Svein; Nunez, C; Espín, Guadalupe; Cocotl-Yanez, Miguel (Journal article; Peer reviewed, 2018)Azotobacter vinelandii produces differentiated cells, called cysts, surrounded by two alginate layers, which are necessary for their desiccation resistance. This alginate contains variable proportions of guluronate residues, ...