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.
2017
Authors
Mihaela-Olivia Dobrica Catalin Lazar Lisa Paruch Hanne Skomedal Hege Særvold Steen Sissel Haugslien Catalin Tucureanu Iuliana Caras Adrian Onu Sonya Ciulean Alexandru Branzan Jihong Liu Clarke Crina Stavaru Norica Branza-NichitaAbstract
Chronic Hepatitis B Virus (HBV) infection leads to severe liver pathogenesis associated with significant morbidity and mortality. As no curable medication is yet available, vaccination remains the most costeffective approach to limit HBV spreading and control the infection. Although safe and efficient, the standard vaccine based on production of the small (S) envelope protein in yeast fails to elicit an effective immune response in about 10% of vaccinated individuals, which are at risk of infection. One strategy to address this issue is the development of more immunogenic antigens. Here we describe a novel HBV antigen obtained by combining relevant immunogenic determinants of S and large (L) envelope proteins. Our approach was based on the insertion of residues 21-47 of the preS1 domain of the L protein (nomenclature according to genotype D), involved in virus attachment to hepatocytes, within the external antigenic loop of S. The resulting S/preS121-47 chimera was successfully produced in HEK293T and Nicotiana benthamiana plants, as a more economical recombinant protein production platform. Comparative biochemical, functional and electron microscopy analysis indicated assembly of the novel antigen into subviral particles in mammalian and plant cells. Importantly, these particles preserve both S- and preS1-specific epitopes and elicit significantly stronger humoral and cellular immune responses than the S protein, in both expression systems used. Our data promote this antigen as a promising vaccine candidate to overcome poor responsiveness to the conventional, S protein-based, HBV vaccine.
2016
Abstract
No abstract has been registered
Authors
Frans-Jan W. Parmentier Daniel Rasse Georg Heinrich Hansen Jarle W. Bjerke Simon Weldon Magnus LundAbstract
No abstract has been registered
Authors
Elisa Lopez-Capel Kor Zwart Simon Shackley Romke Postma John Stenström Daniel Rasse Alice Budai Bruno GlaserAbstract
No abstract has been registered
Authors
Ma Xingzhu Baoku Zhou Alice Budai Alhaji S. Jeng Xiaoyu Hao Dan Wei Yulan Zhang Daniel RasseAbstract
Biochar is a carbon-rich solid product obtained by pyrolysis of biomass. Here, we investigated multiple biochars produced under slow pyrolysis (235–800 °C), flash carbonization, and hydrothermal carbonization (HTC), using Scanning Electron Microscope—Energy Dispersive X-ray Spectroscopy (SEM-EDX) in order to determine whether SEM-EDX can be used as a proxy to characterize biochars effectively. Morphological analysis showed that feedstock has an integrated structure compared to biochar; more pores were generated, and the size became smaller when the temperature increased. Maximum carbon content (max. C) and average carbon content (avg. C) obtained from SEM-EDX exhibited a positive relationship with pyrolysis temperature, with max. C correlating most closely with dry combustion total carbon content. The SEM-EDX O/C ratios displayed a consistent response with the highest treatment temperature (HTT). The study suggests that SEM-EDX produces highly consistent C, oxygen (O), and C/O ratios that deserve further investigation as an operational tool for characterization of biochar products.
Authors
Hanna Marika Silvennoinen Christophe Moni Teresa Gómez de la Bárcena Mats Höglind Daniel RasseAbstract
No abstract has been registered
Abstract
Biochar and its properties can be significantly altered according to how it is produced, and this has ramifications towards how biochar behaves once added to soil. We produced biochars from corncob and miscanthus straw via different methods (slow pyrolysis, hydrothermal and flash carbonization) and temperatures to assess how carbon cycling and soil microbial communities were affected. Mineralization of biochar, its parent feedstock, and native soil organic matter were monitored using 13C natural abundance during a 1-year lab incubation. Bacterial and fungal community compositions were studied using T-RFLP and ARISA, respectively. We found that persistent biochar-C with a half-life 60 times higher than the parent feedstock can be achieved at pyrolysis temperatures of as low as 370 °C, with no further gains to be made at higher temperatures. Biochar re-applied to soil previously incubated with our highest temperature biochar mineralized faster than when applied to unamended soil. Positive priming of native SOC was observed for all amendments but subsided by the end of the incubation. Fungal and bacterial community composition of the soil-biochar mixture changed increasingly with the application of biochars produced at higher temperatures as compared to unamended soil. Those changes were significantly (P < 0.005) related to biochar properties (mainly pH and O/C) and thus were correlated to pyrolysis temperature. In conclusion, our results suggest that biochar produced at temperatures as low as 370 °C can be utilized to sequester C in soil for more than 100 years while having less impact on soil microbial activities than high-temperature biochars.
Authors
Yanliang Wang Tore Krogstad Jihong Liu Clarke Moritz Hallama Anne Falk Øgaard Susanne Eich-Greatorex Ellen Kandeler Nicholas ClarkeAbstract
Many arable lands have accumulated large reserves of residual phosphorus (P) and a relatively large proportion of soil P is less available for uptake by plants. Root released organic anions are widely documented as a key physiological strategy to enhance P availability, while limited information has been generated on the contribution of rhizosphere organic anions to P utilization by crops grown in agricultural soils that are low in available P and high in extractable Ca, Al, and Fe. We studied the role of rhizosphere organic anions in P uptake from residual P in four common crops Triticum aestivum, Avena sativa, Solanum tuberosum, and Brassica napus in low- and high-P availability agricultural soils from long-term fertilization field trials in a mini-rhizotron experiment with four replications. Malate was generally the dominant organic anion. More rhizosphere citrate was detected in low P soils than in high P soil. B. napus showed 74–103% increase of malate in low P loam, compared with clay loam. A. sativa had the greatest rhizosphere citrate concentration in all soils (5.3–15.2 μmol g−1 root DW). A. sativa also showed the highest level of root colonization by arbuscular mycorrhizal fungi (AMF; 36 and 40%), the greatest root mass ratio (0.51 and 0.66) in the low-P clay loam and loam respectively, and the greatest total P uptake (5.92 mg P/mini-rhizotron) in the low-P loam. B. napus had 15–44% more rhizosphere acid phosphatase (APase) activity, ~0.1–0.4 units lower rhizosphere pH than other species, the greatest increase in rhizosphere water-soluble P in the low-P soils, and the greatest total P uptake in the low-P clay loam. Shoot P content was mainly explained by rhizosphere APase activity, water-soluble P and pH within low P soils across species. Within species, P uptake was mainly linked to rhizosphere water soluble P, APase, and pH in low P soils. The effects of rhizosphere organic anions varied among species and they appeared to play minor roles in improving P availability and uptake.
Authors
Marcin Stróz ̇ecki Mateusz Samson Bogdan Chojnicki Jacek Leśny Christophe Moni Marek Urbaniak Janusz Olejnik Radoslaw Juszczak Hanna Marika SilvennoinenAbstract
No abstract has been registered
Authors
Atle Mysterud William Ryan Easterday Vetle Malmer Stigum Anders Aas Erling Meisingset Hildegunn ViljugreinAbstract
Global environmental changes are causing Lyme disease to emerge in Europe. The life cycle of Ixodes ricinus, the tick vector of Lyme disease, involves an ontogenetic niche shift, from the larval and nymphal stages utilizing a wide range of hosts, picking up the pathogens causing Lyme disease from small vertebrates, to the adult stage depending on larger (non-transmission) hosts, typically deer. Because of this complexity the role of different host species for emergence of Lyme disease remains controversial. Here, by analysing long-term data on incidence in humans over a broad geographical scale in Norway, we show that both high spatial and temporal deer population density increase Lyme disease incidence. However, the trajectories of deer population sizes play an overall limited role for the recent emergence of the disease. Our study suggests that managing deer populations will have some effect on disease incidence, but that Lyme disease may nevertheless increase as multiple drivers are involved.