Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Abstract
No abstract has been registered
Authors
Carl Gunnar Fossdal Ari M. Hietala Igor A. Yakovlev Gustav Vaaje-Kolstad Emil Stefaczyk Halvor SolheimAbstract
The GH61 represents the most enigmatic Glycoside Hydrolase Family (GH) regarding putative enzymatic activity and importance in cellulose degradation. Heterobasidion irregulare is a necrotizing pathogen and white rot fungus, causing enormous damages in conifer forests.The genome of H. irregulare allowed identification of ten HiGH61 genes. qRT-PCR analysis separate the HiGH61 members into two groups; one that show up regulation on lignocellulosic substrates and another that show either down regulation or constitutive expression. This grouping suggests that the fungus relates different sets of GH61s for different substrates, like in the various stages of necrotizing and saprophytic growth on the host.One HiGH61 showed up to 17000 fold increase on spruce heartwood suggesting a pivotal role in cellulose decomposition during saprophytic growth. Sequence analysis of these genes reveals that all GH61s but one possess the conserved metal binding motif predicted to be essential for activity.The sequences also divide into groups having either an insert near the N-terminus or an insert near the second catalytic histidine, which both may represent extensions of the substrate binding surface. Three HiGH61s encode cellulose-binding modules (CBM1), indicating direct targeting of crystalline cellulose, two being up regulated on pure cellulose.There was a common substrate-specific induction patterns of the HiGH61s with several reference cellulolytic and hemicellulolytic GHs, this taken together with their low levels on media lacking lignocellulose, reflect the concerted nature of cell wall polymer degradation.
Authors
Igor A. Yakovlev Gustav Vaaje-Kolstad Ari Hietala Emil Stefanczyk Halvor Solheim Carl Gunnar FossdalAbstract
No abstract has been registered
Authors
Sekhar Udaya Nagothu David Nicholas Barton A.K. Gosain K. Palanisami Kota Tirupathaiah Per Stålnacke Sanjay Gupta Johannes DeelstraAbstract
No abstract has been registered
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No abstract has been registered
Authors
Arne StensvandAbstract
No abstract has been registered
Authors
Aruppillai Suthaparan Arne Stensvand Knut Asbjørn Solhaug Sissel Torre Leiv M. Mortensen David M. Gadoury R.C. Seem Hans Ragnar GislerødAbstract
No abstract has been registered
Abstract
The study describes the development of surface mould and blue stain fungi on painted wooden claddings exposed to outdoor weathering. The materials consisted of Norway spruce (Picea abies) claddings that were processed from inner boards, outer boards, and edge-grained boards with known origin. Heartwood proportion, density, annual ring width, knot diameters and relative knot area were measured, and all boards were coated with the same water-borne alkyd modified acrylic paint system. Most of the tangentially sawn boards were coated on the side facing the pith, but a sub-sample was coated on the opposite side for comparison. The specimens were exposed with a 45° angle of inclination facing south in a field trial in Oslo from 2007 to 2011, and mould growth was evaluated visually according to EN 927-3. The development of mould rating was described with an ordinal logistic regression model. The model predicts expected mould rating to follow a sigmoid curve with some deviation in the first part. Neither wood properties nor manufacturing characteristics had any significant effect on the model, and this may in part be due to the use of a high performance coating system.
Authors
Dag-Ragnar BlystadAbstract
No abstract has been registered
Abstract
No abstract has been registered