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.
2025
Sammendrag
Wood modification by impregnation with phenol-formaldehyde (PF) resins is a promising method to improve the woods’ fungal decay resistance, weathering resistance, and dimensional stability. Recent research indicates that 30% of the non-renewable phenol may be substituted by renewable softwood kraft lignin cleavage products obtained through microwave-assisted pyrolysis. Pinus sylvestris sapwood modified with this resin has good fungal decay resistance but slightly enhanced formaldehyde emission. While these results on solid wood indicate a high potential of the method, the properties of modified plywood may differ, and the weathering resistance has not been studied. In this study, formaldehyde emission, weathering resistance and fungal decay resistance against three basidiomycetes (Trametes versicolor, Rhodonia placenta, and Gloeophyllum trabeum) of plywood modified with pure PF resin and PF resin with 30% substitution of the phenol by lignin cleavage products were analysed. The 30% lignin cleavage product substitution didn’t affect the plywood’s fungal decay resistance, with less than 1% initial mass loss in all modified specimens. While the decay resistance improved significantly for all modified samples compared to reference samples, weathering resistance slightly declined with phenol substitution compared to pure PF resin modification. The formaldehyde emissions of the plywood modified with both resins were in similar ranges to that of unmodified reference plywood. Overall, plywood with good properties for exterior applications may be produced even with the substitution of 30% of the phenol by lignin cleavage products, allowing for increased use of renewable resources.
Sammendrag
No abstract has been registered
Sammendrag
Diptera larvae and Nematoda were extracted from soil samples collected in the foreland of the receding Hardangerjøkulen glacier near Finse, central south Norway. Samples were standardized by being taken in snowbed habitats with Salix herbacea L. vegetation. Diptera larvae were sampled in twenty plots from 32 to 227 years age, complemented by five plots with about 10,000-year-old soil. Nematodes were studied in soils of 4, 37, 39, 62, 78, 119, and 204 years age. There was a rapid colonization in young soils of both Diptera larvae and nematodes. Brachycera larvae were sparsely represented, and Sciaridae and Chironomidae larvae were most numerous in soils younger than 50 years. Genera of Chironomidae larvae were Bryophaenocladius, Pseudosmittia, Parasmittia, and Smittia. The number of nematode taxa increased from six in the youngest soil to fourteen in the oldest. Bacterial feeders were dominated by the genus Rhabditis sensu lato and fungal feeders by Tylenchus sensu lato. The plant-parasitic Paratylenchus sp. was present at 4 years, with highest abundance at 39 years. The abundance of omnivores (subfamily Dorylaiminae) did not vary between soil ages, but predators (fam. Mononchidae and genus Tripyla) were more abundant at 78 and 119 years.
Forfattere
Ana-Maria Pantazica Alexander Hammel Iuliana Caras Irina Ionescu Catalin Tucureanu Adrian Onu Maria Murace Jihong Liu Clarke Crina Stavaru Norica Branza-Nichita Ralph BockSammendrag
Microalgae represent promising production factories for the light-driven, cost-effective production of recombinant proteins. The red microalga Porphyridium purpureum displays particularly favourable transgene expression properties due to the episomal maintenance of transformation vectors at high copy numbers in the nucleus. In this work, we explored the potential of Porphyridium purpureum to synthesise a candidate vaccine against Hepatitis B virus (HBV). We show high-yield expression of an HBV chimeric surface antigen and efficient assembly of virus-like particles (VLPs) in algal cells. We established a purification protocol for the VLPs and conducted vaccination studies in experimental animals. The results demonstrate that the alga-produced HBV antigen elicits superior humoral and cellular immune responses compared to a commercial HBV vaccine produced in yeast. The antigen triggers virus-neutralising antibodies against different HBV variants, including vaccine-escape mutations that evade the immune response to current vaccines in humans. Our work establishes Porphyridium as a highly promising production platform for vaccines and other proteinaceous biopharmaceuticals.
Forfattere
Atle Wehn HegnesSammendrag
No abstract has been registered
Forfattere
Anita SønstebySammendrag
No abstract has been registered
Forfattere
Anita SønstebySammendrag
No abstract has been registered
Forfattere
Tomasz Leszek WoznickiSammendrag
No abstract has been registered
Forfattere
Katrine Marie Brynildsrud Peter Horvath Michael Angeloff Wenche Dramstad Adam Eindride Naas Kerstin Potthoff Anders BrynSammendrag
Expanding cities and urban densification is one of the major threats to biodiversity, ecosystem services and human welfare. Using Oslo, the capital city of Norway, as a case study this study addresses the following questions: (i) What vegetation changes have occurred between 1980s and 2021 and to what extent? (ii) What are the potential consequences of documented changes for biodiversity and other functions of green spaces? (iii) What future direction is the present development plan aiming for? To answer these questions, detailed vegetation maps (1:10 000) of Oslo from around 1980s were remapped in situ in 2021. We present results on land cover transformations, area statistics, and analyses of ecological impacts using landscape metrics. Our results document that large areas previously covered by vegetation types and cultivated land have been lost to urban densification. Housing dominated the new use. This loss of areas with vegetation types will affect ecosystem diversity negatively. On average, the total area and the mean patch area of each vegetation type decreased, whereas the mean Euclidean nearest-neighbor distance increased. These changes have lowered connectivity and increased fragmentation. Despite explicitly stated aims, previous efforts to reduce loss of areas with high biodiversity and maintain urban green spaces have not succeeded, and the planned future urban development indicates that a further decrease will follow in the next decades.
Forfattere
Begüm Bilgiç Thea Os Andersen Getachew Birhanu Abera Michal Sposob Lu Feng Svein Jarle HornSammendrag
Syngas biomethanation represents a promising pathway to convert recalcitrant feedstocks into biomethane. However, the hydrogen (H2) content in syngas is often insufficient or fluctuates, which affects the overall performance. This study evaluated the effect of H2 addition on syngas conversion efficiency and microbial community dynamics using two trickle bed reactors (TBRs). One TBR was fed with syngas, while another received syngas supplemented with H2. Both TBRs demonstrated the feasibility of converting CO from syngas to methane, with the H2 supplemented TBR outperforming the syngas-only TBR. The H2 supplemented TBR achieved over 90 % conversion rate at a gas loading rate of 15 NL/Lreactor/d and reached peak methane production at a gas loading rate at 20 NL/Lreactor/d. Microbial community structure analysis revealed a dominance of Methanobacterium, a known thermophilic hydrogenotrophic methanogen. Although H2 addition enhanced performance, a decline in conversion efficiency at higher gas loading rates highlights the need for further optimization.