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.
2019
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Authors
Arohi Srivastava Sharad Mohan Tim H. Mauchline Keith DaviesAbstract
Pasteuria spp. belong to a group of genetically diverse endospore-forming bacteria (phylum: Firmicutes) that are known to parasitize plant-parasitic nematodes and water fleas (Daphnia spp.). Collagen-like fibres form the nap on the surface of endospores and the genes encoding these sequences have been hypothesised to be involved in the adhesion of the endospores of Pasteuria spp. to their hosts. We report a group of 17 unique collagen-like genes putatively encoded by Pasteuria penetrans (strain: Res148) that formed five different phylogenetic clusters and suggest that collagen-like proteins are an important source of genetic diversity in animal pathogenic Firmicutes including Pasteuria. Additionally, and unexpectedly, we identified a putative collagen-like sequence which had a very different sequence structure to the other collagen-like proteins but was similar to the protein sequences in Megaviruses that are involved in host-parasite interactions. We, therefore, suggest that these diverse endospore surface proteins in Pasteuria are involved in biological functions, such as cellular adhesion; however, they are not of monophyletic origin and were possibly obtained de novo by mutation or possibly through selection acting upon several historic horizontal gene transfer events.
Abstract
Recent studies on using soil enhancer material, such as biochar, provide varying results from a soil hydrological and chemical perspective. Therefore, research focusing on soil-biochar-plant interactions is still necessary to enhance our knowledge on complex effects of biochar on soil characteristics. The present study investigated the changes in soil water content (SWC) and soil respiration (belowground CO2 production) over time during the growth of Capsicum annuum (pepper) in pot experiments. Concurrently, we investigated the influence of grain husk biochar with the amount of 0, 0.5%, 2.5%, and 5.0% (by weight) added to silt loam soil. Pepper plants were grown under natural environmental conditions to better represent field conditions, and additional irrigation was applied. SWC among treatments showed minor changes to precipitation during the beginning of the study while plants were in the growing phase. The highest water holding throughout the experiment was observed in the case of BC5.0. CO2 production increased in biochar amended soils during the first few days of the experiments; while the overall cumulative CO2 production was the highest in control and the lowest in BC2.5 treatments. We used the HYDRUS 1D soil hydrological model to simulate changes in SWC, using the control treatment without biochar as a reference data source for model calibration. The simulated SWC dynamics fitted well the measured ones in all treatments. Therefore, the HYDRUS 1D can be an exceptionally valuable tool to predict the hydrological response of different amount of biochar addition to silt loam soil including plant growth.
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This study addresses changes in visual appearance of unpainted wood materials exposed outdoors. Specimens of aspen (Populus tremula), Norway spruce (Picea abies), untreated Scots pine (Pinus sylvestris), DMDHEU-modified Scots pine and acetylated Radiata pine (Pinus radiata) were exposed facing south in Ås, Norway for 62 weeks. During this period, mould growth coverage, lightness (L*) and the uniformity of the weather grey colour were assessed. Mould growth coverage was evaluated visually using a rating system. L* and the uniformity were evaluated using image analysis. The increase in mould rating of the wood materials developed in varying speed, but all specimens had reached the maximum rating after 42 weeks. Until then, the changes in L* correlated significantly with the mould rating. However, the specimens continued to darken after they had reached maximum mould rating. DMDHEU was the only material that obtained a more uniform colour as a consequence of the weathering.
Authors
Christophe Moni Hanna Marika Silvennoinen Bruce A. Kimball Erling Fjelldal Marius Brenden Ingunn Burud Andreas Svarstad Flø Daniel RasseAbstract
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Abstract
Mediterranean climate areas are home to highly relevant and distinctive agro-ecosystems, where sustainability is threatened by water scarcity and continuous loss of soil organic carbon. In these systems, recycling strategies to close the loop between crop production (and agrorelated industries) and soil conservation are of special interest in the current context of climate change mitigation. Pyrolysis represents a recycling option for the production of energy and biochar, a carbonaceous product with a wide range of environmental and agronomic applications. Considering that biochar functionality depends on both the original biomass and the pyrolysis conditions, we produced and characterized 22 biochars in order to evaluate their potential to sequester C and modify soil physicochemical properties. The pore size distribution was a function of the original biomass and did not change with the temperature of pyrolysis. The highest number of pores within the size 0.2−30 μm, relevant for plant available water retention, was reached at 600 °C. However, ideal pyrolysis conditions to optimize C stability and hydrologic properties was reached at 400 °C in woody derived biochars, as higher temperatures lead to a nontransient hydrophobicity. This study highlights relevant physicochemical properties of locally derived biochars that can be used to tackle specific challenges in Mediterranean agroecosystems.
Abstract
Prosjektleder Øyvind Kaste