Browsing NTNU Open by Author "Ertesvåg, Helga"

A structural and functional study of AlgE mannuronan C5-epimerases and lyases from Azotobacter vinelandii and Azotobacter chroococcum

Sønsteby, Sigrid Tejera (Master thesis, 2021)

Alginat er lineære, anioniske polysakkarider, som består av (1→4) bundet β-D-mannuron- syre (M) og α-L-guluronsyre (G). Hvert polysakkarid syntetiseres først som mannuronan og G-enheter introduseres av mannuronan C5-epimeraser ...

A study of AlgE-type mannuronan C-5-epimerases from Azotobacter chroococcum and Azotobacter vinelandii

Hervig, Silje Trå (Master thesis, 2022)

Alginat er en biopolymer bestående av beta-D-mannuronsyre (M) og alfa-L-guluronsyre (G), bundet sammen med 1-4 glykosidbindinger. Alginat er biokompatibelt og kan danne hydrogeler, som for eksempel kan brukes i medisinsk ...

Alginate Biosynthesis Factories in Pseudomonas fluorescens : Localization and Correlation with Alginate Production Level

Maleki, Susan; Almaas, Eivind; Zotchev, Sergey; Valla, Svein; Ertesvåg, Helga (Journal article; Peer reviewed, 2016)

Pseudomonas fluorescens is able to produce the medically and industrially important exopolysaccharide alginate. The proteins involved in alginate biosynthesis and secretion form a multiprotein complex spanning the inner ...

Alginate-modifying enzymes: Biological roles and biotechnological uses

Ertesvåg, Helga (Journal article; Peer reviewed, 2015)

Alginate denotes a group of industrially important 1-4-linked biopolymers composed of the C-5-epimers β-D-mannuronic acid (M) and α-L-guluronic acid (G). The polysaccharide is manufactured from brown algae where it constitutes ...

Assessing the Capability of Pseudomonas fluorescens and Pseudomonas savastanoi to Produce G-Rich Alginates

May, Carlan (Master thesis, 2020)

Alginate is a naturally occurring polymer produced by brown algae and certain bacterial species – specifically those in the genera Azotobacter and Pseudomonas. This polymer has many applications including as a thickening ...

ATP-Dependent Citrate Lyase and Glycerol 3-Phosphate Dehydrogenase in Aurantiochytrium T66: An Attempted In Vivo Analysis and Heterologous Expression

Jakobsen, Margit Ertresvåg (Master thesis, 2019)

Thraustochytrider er industrielt interessante mikroorganismer på grunn av deres evne til å produsere store mengder lipider, spesielt omega-3 fettsyren dokosaheksaensyre (DHA). Metabolismen til disse organismene er ikke ...

Combined Metabolome and Lipidome analyses for in-depth characterization of lipid accumulation in the DHA producing Aurantiochytrium sp. T66

Bartosova, Zdenka; Ertesvåg, Helga; Nyfløt, Eirin Lishaugen; Kämpe, Kristoffer; Aasen, Inga Marie; Bruheim, Per (Peer reviewed; Journal article, 2021)

Thraustochytrids are marine heterotrophic microorganisms known for their potential to accumulate docosahexaenoic acid (DHA)-enriched lipids. There have been many attempts to improve thraustochytrid DHA bioprocesses, ...

Constructing a Hybrid De novo Genome Assembly of Aurantiochytrium sp. T66 using MinION and Illumina reads to Improve the Quality of its Annotation

Hamza, Amir (Master thesis, 2021)

Thraustochytrids are unicellular marine heterotrophs which have attention due to their ability to accumulate high amount of important nutraceuticals, in particular polyunsaturated fatty acids (PUFA). However, their ...

Construction and characterization of broad-host-range reporter plasmid suitable for on-line analysis of bacterial host responses related to recombinant protein production

Gawin, Agnieszka; Peebo, Karl; Sebastian, Hans; Ertesvåg, Helga; Irla, Marta Katarzyna; Neubauer, Peter; Brautaset, Trygve (Journal article; Peer reviewed, 2019)

Background Bacteria are widely used as hosts for recombinant protein production due to their rapid growth, simple media requirement and ability to produce high yields of correctly folded proteins. Overproduction of ...

Draft genome sequence of the docosahexaenoic acid producing thraustochytrid Aurantiochytrium sp. T66

Liu, Bin; Ertesvåg, Helga; Aasen, Inga Marie; Vadstein, Olav; Brautaset, Trygve; Heggeset, Tonje Marita Bjerkan (Journal article; Peer reviewed, 2016)

Thraustochytrids are unicellular, marine protists, and there is a growing industrial interest in these organisms, particularly because some species, including strains belonging to the genus Aurantiochytrium, accumulate ...

Effekten av å aktivere en genklynge med potensiell kitin syntase aktivitet i Erwinia carotovora

Hagen, Kjersti Næss (Master thesis, 2011)

Kitin er en langkjedet, nitrogenholdig polymer som er bygget opp av N-acetyl-glukosamin-enheter (GlcNAc), og finnes i blant annet det ytre skallet til leddyr, og i celleveggen til sopp. Biosyntese av kitin er katalysert ...

Functional characterization of three Azotobacter chroococcum alginate-modifying enzymes related to the Azotobacter vinelandii AlgE mannuronan C-5-epimerase family

Gawin, Agnieszka Maria; Tietze, Lisa; Aarstad, Olav Andreas; Aachmann, Finn Lillelund; Brautaset, Trygve; Ertesvåg, Helga (Peer reviewed; Journal article, 2020)

Bacterial alginate initially consists of 1-4-linked beta-D-mannuronic acid residues (M) which can be later epimerized to alpha-L-guluronic acid (G). The family of AlgE mannuronan C-5-epimerases from Azotobacter vinelandii ...

Green foam-based methods of mineral and ion separation

Jain, Garima; Havskjold, Håkon; Dhar, Priyanka; Ertesvåg, Helga; Chernyshova, Irina; Kota, Hanumantha Rao (Chapter, 2020)

We discuss an important gap in the literature on progress toward the development of green (microbial-derived) reagents in conventional (froth flotation) and emerging (foam flotation)separation methods. For comparison, we ...

Guluronic acid content as a factor affecting turbidity removal potential of alginate

Moral, Cigdem Kivilcimdan; Ertesvåg, Helga; Sanin, F. Dilek (Journal article; Peer reviewed, 2016)

Alginates are natural polymers composed of mannuronic and guluronic acid residues. They are currently extracted from brown algae; however, alginate can also be synthesized by some species of Azotobacter and Pseudomonas. ...

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 ...