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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

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Abstract

Environmental transmission of antibiotic resistance poses a significant threat to human health by undermining the efficacy of therapeutic interventions against bacterial infections. Agricultural practices, particularly the application of organic fertilizers derived from animal manure, are major contributors to the spread of antibiotic resistance determinants (ARDs) in soil ecosystems. However, the fates of ARDs and their bacterial hosts in soil following organic fertilization as well as the impact of water management regimes remain poorly understood. We investigated the attenuation and persistence of ARDs in soil following organic fertilization under water management practices of upland, continuous flooding, and intermittent flooding. Most ARDs introduced via the organic fertilizer exhibited significant attenuation, with half-lives ranging from 19 to 50 days, primarily due to the decline of fertilizer-derived bacterial hosts. Specific ARDs, such as aph(3’)-IIIa and tetO, persisted across all treatments. Upland conditions accelerated the attenuation of ARDs and their pathogenic hosts compared to f looding conditions, which prolonged their survival and promoted horizontal gene transfer. The divergent responses of ARD composition and soil bacterial communities to the environmental variables revealed a unique dissemination pattern, wherein the soil co-occurring bacterial communities served as critical hubs for the dissemination of ARDs and their bacterial hosts from organic fertilizers. The soil co-occurring bacterial communities exhibited strong interspecies interactions and high sensitivity to environmental changes. Targeted strategies to disrupt these assembly hubs may provide an effective way to mitigate the spread of antibiotic resistance from organic fertilizers to soil ecosystems.

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Abstract

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.

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Abstract

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.

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Abstract

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.