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.
2018
Authors
Kine Svensson Oda Marie Kjørlaug Matthew J. Higgins Roar Linjordet Svein Jarle HornAbstract
Post-anaerobic digestion (PAD) treatment technologies have been suggested for anaerobic digestion (AD) to improve process efficiency and assure hygenization of organic waste. Because AD reduces the amount of organic waste, PAD can be applied to a much smaller volume of waste compared to pre-digestion treatment, thereby improving efficiency. In this study, dewatered digestate cakes from two different AD plants were thermally hydrolyzed and dewatered, and the liquid fraction was recirculated to a semi-continuous AD reactor. The thermal hydrolysis was more efficient in relation to methane yields and extent of dewaterability for the cake from a plant treating waste activated sludge, than the cake from a plant treating source separated food waste (SSFW). Temperatures above 165 °C yielded the best results. Post-treatment improved volumetric methane yields by 7% and the COD-reduction increased from 68% to 74% in a mesophilic (37 °C) semi-continuous system despite lowering the solid retention time (from 17 to 14 days) compared to a conventional system with pre-treatment of feed substrates at 70 °C. Results from thermogravimetric analysis showed an expected increase in maximum TS content of dewatered digestate cake from 34% up to 46% for the SSFW digestate cake, and from 17% up to 43% in the sludge digestate cake, after the PAD thermal hydrolysis process (PAD-THP). The increased dewatering alone accounts for a reduction in wet mass of cake leaving the plant of 60% in the case of sludge digestate cake. Additionaly, the increased VS-reduction will contribute to further reduce the mass of wet cake.
Authors
Málfríður Bjarnadóttir Björn Viðar Aðalbjörnsson Anna Nilsson Rasa Slizyte Michael Roleda Guðmundur Óli Hreggviðsson Ólafur H. Friðjónsson Rósa JónsdóttirAbstract
The red seaweed Palmaria palmata has previously been reported to have high protein content high in essential amino acids. To extract the proteins a rigid cell wall consisting mainly of β-(1→4)/β-(1→3)-D-xylans must be disrupted. Different methods have been used to overcome this problem along with various methods used for protein evaluation. In this study, the effect of enzymatic pre-treatment on protein extraction was examined. Both enzymatic hydrolysis with xylanase and protease were tested. The amino acid content of the fractions was examined after extraction. The amino acid composition was similar to what has previously been reported; P. palmata was high in essential amino acids. Accordingly, a nitrogen-to-protein conversion factor was calculated for each fraction individually and protein results were compared with calculation using the proximate 6.25 conversion factor. The nitrogen-to-protein conversion factor varied between fractions but all factors were significantly lower than the popularly used 6.25 indicating that this conversion factor for processed P. palmata is effectively and considerably overestimating the protein content. Enzymatic pre-treatment with xylanase resulted in enhanced amino acid content and successful protein extraction. Enzymatic hydrolysis using protease resulted in higher protein content in the liquid extract compared to hydrolysis with xylanase, due to the release of proteins, peptides, and amino acids. Therefore, hydrolysis with protease is not suitable to extract proteins from P. palmata with the method described within this study but might be an optimal method to examine the bioactivity by extracting the protein hydrolysates. However, the result from this study confirm that hydrolysis with xylanase is a feasible choice to extract proteins of good quality from P. palmata.
Abstract
No abstract has been registered
Authors
Pierrick Francois Denis Stévant Erlend Indergård Aðalheiður Ólafsdóttir Hélène Marfaing Wenche Merete Emblem Larssen Joël Fleurence Michael Roleda Turid Rustad Rasa Slizyte Tom Ståle NordtvedtAbstract
This is a post-peer-review, pre-copyedit version of an article published in [Journal of Applied Phycology] Locked until 23.3.2019 due to copyright restrictions. The final authenticated version is available online at: https://link.springer.com/article/10.1007%2Fs10811-018-1451-0
Authors
Misganu Debella-Gilo Svein Olav Krøgli Vibeke Stærkebye Nørstebø Wenche Dramstad Gerardo Alfredo Perez ValdesAbstract
No abstract has been registered
Authors
Vibeke Stærkebye Nørstebø Gerardo Alfredo Perez Valdes Svein Olav Krøgli Wenche Dramstad Misganu Debella-Gilo Kristin Tolstad UggenAbstract
No abstract has been registered
Authors
Anne-Grete Roer Hjelkrem Heidi Udnes Aamot Guro Brodal Einar Strand Torfinn Torp Simon G. Edwards Ruth Dill-Macky Ingerd Skow HofgaardAbstract
No abstract has been registered
Authors
Hallvard Jensen Paul Eric Aspholm Bjørn Frantzen Tor-Arne Bjørn Eva Narten Høberg Thomas Holm CarlsenAbstract
No abstract has been registered
Authors
Merethe Kleiven Lisa Magdalena Rossbach Julian Alberto Gallego-Urrea Dag Anders Brede Deborah H Oughton Claire CoutrisAbstract
Using Caenorhabditis elegans as a model organism, this study addresses the potential linkage between toxicity of NM300K Ag nanoparticles (AgNPs), their particle size distribution and the presence of dissolved Ag in the test media. Of the three endpoints assessed (growth, fertility and reproduction), reproduction was the most sensitive, with 50% effect concentration (EC50) ranging from 0.26-0.84 mg Ag L-1 and 0.08-0.11 mg Ag L-1 for NM300K and AgNO3, respectively. Silver uptake by C. elegans was similar for both forms of Ag, while bioaccumulation was higher in AgNO3 exposure. The observed differences in toxicity between NM300K and AgNO3 did not correlate to bioaccumulated Ag, which suggests the toxicity to be a function of the type of exposing agent (AgNPs vs AgNO3) and their mode of action. Before addition of the food source, E. coli, size fractionation revealed that dissolved Ag comprised 13-90 % and 4-8 % of total Ag in the AgNO3 and NM300K treatments, respectively. No dissolved Ag was detectable in the actual test media, due to immediate Ag adsorption to bacteria. Results from the current study highlight that information on behavior and characterization of exposure conditions is essential for nanotoxicity studies.
Authors
Manuel J. Steinbauer John-Arvid Grytnes Gerald Jurasinski Aino Kulonen Jonathan Lenoir Harald Pauli Christian Rixen Manuela Winkler Manfred Bardy-Durchhalter Elena Barni Anne D. Bjorkman Frank T. Breiner Sarah Burg Patryk Czortek Melissa A. Dawes Anna Delimat Stefan Dullinger Brigitta Erschbamer Vivian Astrup Felde Olatz Fernández-Arberas Kjetil Farsund Fossheim Daniel Gómez-García Damien Georges Erlend T. Grindrud Sylvia Haider Siri Vatsø Haugum Hanne Henriksen Maria J. Herreros Bogdan Jaroszewicz Francesca Orinda Holl Jaroszynska Robert Kanka Jutta Kapfer Kari Klanderud Ingolf Kühn Andrea Lamprecht Magali Matteodo Umberto Morra di Cella Signe Normand Arvid Odland Siri Lie Olsen Sara Palacio Martina Petey Veronika Piscová Blazena Sedlakova Klaus Steinbauer Veronika Stöckli Jens-Christian Svenning Guido Teppa Jean-Paul Theurillat Pascal Vittoz Sarah J. Woodin Niklaus E. Zimmermann Sonja WipfAbstract
Globally accelerating trends in societal development and human environmental impacts since the mid-twentieth century1–7 are known as the Great Acceleration and have been discussed as a key indicator of the onset of the Anthropocene epoch6 . While reports on ecological responses (for example, changes in species range or local extinctions) to the Great Acceleration are multiplying8,9 , it is unknown whether such biotic responses are undergoing a similar acceleration over time. This knowledge gap stems from the limited availability of time series data on biodiversity changes across large temporal and geographical extents. Here we use a dataset of repeated plant surveys from 302 mountain summits across Europe, spanning 145 years of observation, to assess the temporal trajectory of mountain biodiversity changes as a globally coherent imprint of the Anthropocene. We find a continent-wide acceleration in the rate of increase in plant species richness, with five times as much species enrichment between 2007 and 2016 as fifty years ago, between 1957 and 1966. This acceleration is strikingly synchronized with accelerated global warming and is not linked to alternative global change drivers. The accelerating increases in species richness on mountain summits across this broad spatial extent demonstrate that acceleration in climate-induced biotic change is occurring even in remote places on Earth, with potentially far-ranging consequences not only for biodiversity, but also for ecosystem functioning and services.