Background and activities
I am a research professor and adjunct professor at the Department of Biotechnology and Food Science and Nobipol. My research has been focused on microbiology/biochemistry/biotechnology on industrial microorganisms, both basic and applied projects. I teach parts of Biochemistry II and the PhD course BT8120.
Areas of speciality
- Understand and control the biosynthesis of alginate in Pseudomonas fluorescens and Azotobacter vinelandii
- Studies of alginate-modifying enzymes
- Design enzymes with new properties.
- Develop microorganisms (bacteria and thraustochytrids) producing feed ingredients, especially DHA and EPA
- Study the effect of bacterially produced surfactants, proteins and polysaccharides on the floatability of nanosized mineral particles.
- A. vinelandii encystment
- The collection of Actinomycetes from the Trondheim fjord
- Tutoring master and PhD students
Background and expertise
I took my master degree in 1987, and PhD in 1994, both at the University of Trondheim, AVH. From 1987 to 2004 I was employed at SINTEF as a researcher/senior researcher. From 2005 I have been working at NTNU.
My work has been within industrial biotechnology. In most cases the motivation has been to understand the bacteria and the properties of pathways and enzymes in order to ultimately construct bacteria that may produce various products (proteins or metabolites) at levels sufficent for an industrial process. I have now expertise on cloning, homologous recombination and tailoring of genetic tools in different bacteria. Another aspect has been production, purification and characterization of enzymes. the projects have also involved genome mining and the use of other databases to find genes coding for a desired activity or to better understand metbolic pathways.
Scientific, academic and artistic work
Displaying a selection of activities. See all publications in the database
- (2020) Translational regulation of periplasmic folding assistants and proteases as a valuable strategy to improve production of translocated recombinant proteins in Escherichia coli. BMC Biotechnology. vol. 20.
- (2020) Functional characterization of three Azotobacter chroococcum alginate-modifying enzymes related to the Azotobacter vinelandii AlgE mannuronan C-5-epimerase family. Scientific Reports. vol. 10.
- (2020) Green foam-based methods of mineral and ion separation. Multidisciplinary Advances in Efficient Separation Processes.
- (2020) Identification of Regulatory Genes and Metabolic Processes Important for Alginate Biosynthesis in Azotobacter vinelandii by Screening of a Transposon Insertion Mutant Library. Frontiers in Bioengineering and Biotechnology. vol. 7 (475).
- (2019) Construction and characterization of broad-host-range reporter plasmid suitable for on-line analysis of bacterial host responses related to recombinant protein production. Microbial Cell Factories. vol. 18 (80).
- (2019) Lipid and DHA-production in Aurantiochytrium sp. – Responses to nitrogen starvation and oxygen limitation revealed by analyses of production kinetics and global transcriptomes. Scientific Reports. vol. 9.
- (2018) RpoS controls the expression and the transport of the AlgE1-7 epimerases in Azotobacter vinelandii. FEMS Microbiology Letters. vol. 365 (19).
- (2017) Identification of genes affecting alginate biosynthesis in Pseudomonas fluorescens by screening a transposon insertion library. BMC Genomics. vol. 18:11.
- (2017) Identification of a new phosphatase enzyme potentially involved in the sugar phosphate stress response in Pseudomonas fluorescens. Applied and Environmental Microbiology. vol. 83 (2).
- (2017) New insights into Pseudomonas fluorescens alginate biosynthesis relevant for the establishment of an efficient production process for microbial alginates. New Biotechnology. vol. 37.
- (2016) Thraustochytrids as production organisms for docosahexaenoic acid (DHA), squalene, and carotenoids. Applied Microbiology and Biotechnology. vol. 100 (10).
- (2016) Draft genome sequence of the docosahexaenoic acid producing thraustochytrid Aurantiochytrium sp. T66. Genomics Data. vol. 8.
- (2016) Alginate Biosynthesis Factories in Pseudomonas fluorescens : Localization and Correlation with Alginate Production Level. Applied and Environmental Microbiology. vol. 82 (4).
- (2016) Guluronic acid content as a factor affecting turbidity removal potential of alginate. Environmental science and pollution research international. vol. 23 (11).
- (2015) Alginate-modifying enzymes: Biological roles and biotechnological uses. Frontiers in Microbiology. vol. 6 (MAY).
- (2015) Mutational analyses of glucose dehydrogenase and glucose-6-phosphate dehydrogenase genes in Pseudomonas fluorescens reveal their effects on growth and alginate production. Applied and Environmental Microbiology. vol. 81 (10).
- (2014) Safety in numbers: multiple occurrences of highly similar homologs among Azotobacter vinelandii carbohydrate metabolism proteins probably confer adaptive benefits. BMC Genomics. vol. 15 (192).
- (2013) Mapping global effects of the anti-sigma factor MucA in Pseudomonas fluorescens SBW25 through genome-scale metabolic modeling. BMC Systems Biology. vol. 7 (19).
- (2013) Mannuronan C-5 Epimerases Suited for Tailoring of Specific Alginate Structures Obtained by High-Throughput Screening of an Epimerase Mutant Library. Biomacromolecules. vol. 14 (8).
- (2012) Rapid reagentless quantification of alginate biosynthesis in Pseudomonas fluorescens bacteria mutants using FT-IR spectroscopy coupled to multivariate partial least squares regression. Analytical and Bioanalytical Chemistry. vol. 403 (9).
- (2010) Isolation of Mutant Alginate Lyases with Cleavage Specificity for Di-guluronic Acid Linkages. Journal of Biological Chemistry. vol. 285 (46).
- (2009) Enzymatic alginate modification. Alginates: Biology and Applications.
- (2009) Characterization of Three New Azotobacter vinelandii Alginate Lyases, One of Which Is Involved in Cyst Germination. Journal of Bacteriology. vol. 191 (15).
- (2009) Genome sequence of Azotobacter vinelandii, an obligate aerobe specialized to support diverse anaerobic metabolic processes. Journal of Bacteriology. vol. 191 (14).
- (2006) Identification and characterization of an Azotobacter vinelandii type I secretion system responsible for export of the AlgE-Type mannuronan C-5-epimerases. Journal of Bacteriology. vol. 188 (15).
- (2005) Role of the Pseudomonas fluorescens alginate lyase (AlgL) in clearing the periplasm of alginates not exported to the extracellular environment. Journal of Bacteriology. vol. 187 (24).
- (2004) The pseudomonas syringae genome encodes a combined mannuronan C-5-epimerase and O-acetylhydrolase, which strongly enhances the predicted gel-forming properties of alginates. Journal of Biological Chemistry. vol. 279 (28).
- (2003) The Pseudomonas fluorescens AlgG protein, but not its mannuronan C-5-epimerase activity, is needed fro alginate polymer formation. Journal of Bacteriology. vol. 185 (12).