Browsing NTNU Open by Author "Ertesvåg, Helga"
Now showing items 21-38 of 38
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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 ... -
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, ... -
Safety in numbers: multiple occurrences of highly similar homologs among Azotobacter vinelandii carbohydrate metabolism proteins probably confer adaptive benefits
Mærk, Mali; Johansen, Jostein; Ertesvåg, Helga; Drabløs, Finn; Valla, Svein (Journal article; Peer reviewed, 2014)Background Gene duplication and horizontal gene transfer are common processes in bacterial and archaeal genomes, and are generally assumed to result in either diversification or loss of the redundant gene copies. However, ... -
Study and Engineering of Gram- Negative Bacteria as Hosts for Production of Recombinant Proteins and Biopolymers
Gawin, Agnieszka (Doctoral theses at NTNU;2020:173, Doctoral thesis, 2020)Gram-negative bacteria are a large group of prokaryotic organisms that thrive in diverse environments and differ in terms of structure and metabolism. They are capable of producing a variety of natural compounds and ... -
Study of genes Avin5390 and Avin30120's effect on encystment properties in Azotobacter vinelandii
Pedersen, John Leithe (Master thesis, 2019)Azotobacter vinelandii har den uvanlige evnen å gå inn i et metabolsk nedregulert stadie kalt en cyste. Cellen stopper de fleste metabolske aktiviteter og dekker seg selv med to beskyttende lag som forbedrer cellens ... -
Translational regulation of periplasmic folding assistants and proteases as a valuable strategy to improve production of translocated recombinant proteins in Escherichia coli
Gawin, Agnieszka Maria; Ertesvåg, Helga; Hartvigsen Hansen, Sine Alise; Malmo, Jostein; Brautaset, Trygve (Peer reviewed; Journal article, 2020)Background Advantages of translocation of recombinant proteins to the periplasm in Escherichia coli include simplified downstream processing, and improved folding and in vivo activity of the target protein. There are, ... -
Transport av fenyl-lipid i Azotobacter vinelandii
Dalland, Marianne (Master thesis, 2013)Ved lav næringstilgang kan Azotobacter vinelandii gå inn i et cystestadium, hvor en del av fosfolipidene i yttermembranen erstattes med alkylresorcinoler og alkylpyroner. Gener involvert i syntese av alkylresorcinol og ... -
Use of Homologous Recombination to Study Alginate Biosynthesis in Azotobacter vinelandii.
Tingstad, Helga Munkeby (Master thesis, 2021)Alginat er en lineær, anionisk biopolymer bestående av mannuronsyre (M) og guluronsyre (G). Polymeren har mange bruksområder innen industri og er særlig interessant på grunn av dens evne til å danne geler, en egenskap som ... -
Utforsking av seleksjonsmarkørar og effekten av feittsyresyntaseinhibitorar på feittsyresyntese i Aurantiochytrium sp.
Teigen, Marianne (Master thesis, 2019)Thraustochytridar er heterotrofe, marine protistar, som har blitt kommersielt interessante dei siste tiåra sidan dei har ein høg produksjon av docosahexaensyre (DHA), som er ei langkjeda fleirumetta omega-3 feittsyre ... -
Utilizing inhibitors and genetic engineering to study the biosynthesis of unsaturated fatty acids and lipids in two thraustochytrid strains
Rau, E-Ming (Doctoral theses at NTNU;2022:21, Doctoral thesis, 2022)Thraustochytrids are oleaginous heterotrophic marine eukaryotic microbes known to produce large amounts of docosahexaenoic acid (DHA)-containing triacylglycerols (TAGs), and they also synthesize terpenoids like squalene. ...