Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2019
Forfattere
Olav Aaseth Hegnar Barry Goodell Claus Felby Lars Johansson Nicolé Labbe Keonhee Kim Vincent Eijsink Gry Alfredsen Aniko VarnaiSammendrag
The recalcitrance bottleneck of lignocellulosic materials presents a major challenge for biorefineries, including second-generation biofuel production. Because of their abundance in the northern hemisphere, softwoods, such as Norway spruce, are of major interest as a potential feedstock for biorefineries. In nature, softwoods are primarily degraded by basidiomycetous fungi causing brown rot. These fungi employ a non-enzymatic oxidative system to depolymerize wood cell wall components prior to depolymerization by a limited set of hydrolytic and oxidative enzymes. Here, it is shown that Norway spruce pretreated with two species of brown-rot fungi yielded more than 250% increase in glucose release when treated with a commercial enzyme cocktail and that there is a good correlation between mass loss and the degree of digestibility. A series of experiments was performed aimed at mimicking the brown-rot pretreatment, using a modified version of the Fenton reaction. A small increase in digestibility after pretreatment was shown where the aim was to generate reactive oxygen species within the wood cell wall matrix. Further experiments were performed to assess the possibility of performing pretreatment and saccharification in a single system, and the results indicated the need for a complete separation of oxidative pretreatment and saccharification. A more severe pretreatment was also completed, which interestingly did not yield a more digestible material. It was concluded that a biomimicking approach to pretreatment of softwoods using brown-rot fungal mechanisms is possible, but that there are additional factors of the system that need to be known and optimized before serious advances can be made to compete with already existing pretreatment methods.
Sammendrag
Im Laufe der vergangenen 15 Jahre wurden in verschiedenen, vor allem europäischen Ländern große Anstrengungen unternommen, Modelle zur Vorhersage der Gebrauchsdauer von Holzbauteilen zu entwickeln. Heute steht ein System zur Verfügung, mit dem sich Exposition, Dimension, Konstruktionsdetails und die Fähigkeit des Holzes, Wasser aufzunehmen und wieder abzugeben, so miteinander in Beziehung setzen lassen, dass sich das feuchteinduzierte Befallsrisiko für Holzprodukte quantitativ abschätzen lässt. Das Ziel dieser Studie war es, die „Vorhersagekraft“ von Performancemodellen einerseits und unterschiedlichen Gruppen von Holzverwendern andererseits zu vergleichen. Neben Zimmerern und Tischlern wurden auch Holzwissenschaftler, Architekten und Kunden sogenannter „Heimwerkermärkte“ gebeten, die Zeitspanne zwischen Beginn der Exposition und dem ersten Auftreten pilzlicher Holzschäden für eine Reihe von Fallbeispielen mit bekannter Historie und Gebrauchsdauer abzuschätzen. Die verwendeten Modelle sagten die Gebrauchsdauern der Bauteile in den unterschiedlichen Fallbeispielen zufriedenstellend vorher, mit Ausnahme eines Spielgerätes, das aus schutzmittelbehandeltem Holz gefertigt war. Weitere materialspezifische Daten zur Resistenz und zum Feuchteverhalten sind offenbar notwendig, um die Genauigkeit des Modells zu erhöhen. In vielen Fällen lag der Mittelwert der Gebrauchsdauerabschätzung der Befragten ebenfalls recht nahe an der tatsächlich erreichten Gebrauchsdauer. Die Einzelschätzungen unterlagen hierbei jedoch einer extrem hohen Streuung. Expertengruppen, wie z. B. Holzhandwerker und Holzwissenschaftler, vermochten die Gebrauchsdauern nicht genauer vorherzusagen als die Gruppe von Laien. Die Notwendigkeit für umfassende und komplexe Vorhersageinstrumente wurde sehr deutlich, da weder Laien noch Experten sich in der Lage zeigten, ausreichend genau und statistisch verlässlich die Gebrauchsdauern von Holzbauteilen vorherzusagen.
Forfattere
Ed Suttie Christian Brischke Eva Frühwald Hansson Stefania Fortino Jakub Sandak Magdalena Kutnik Gry Alfredsen Christophe Lucas Rod StirlingSammendrag
Det er ikke registrert sammendrag
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Sammendrag
Tømmerstokker kan snart bli til grisefôr, stabilisator i maten og mye mer.
Forfattere
Gry AlfredsenSammendrag
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Sammendrag
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Sammendrag
Understanding the quality of new raw material sources will be of great importance to ensure the development of a circular bioeconomy. Building up quality understanding of wood waste is an important step in this development. In this paper we probe two main questions, one substantial and one theoretical: What different understandings of wood waste quality exist and what significance do they have for the recycling and re-use of this waste fraction? And, what is the evolution of knowledge and sustainable practices of wood waste qualities a case of? The analysis is based on diverse perspectives and forms of methods and empirical material. Studies of policy documents, regulations, standards, etc. have been reviewed to uncover what kind of measures and concepts that have been important for governing and regulating wood waste handling. Interviews concerning wood and wood waste qualities have been conducted with key informants and people visiting recycling and waste management stations in Oslo and Akershus in Norway. By studying quality conceptions through the social birth, production, life, end-of-life and re-birth of wood products, we analyse socio-cultural conditions for sustainability. Furthermore we show how the evolution of knowledge and sustainable practices of wood waste qualities, in the meeting with standards and regulations, is a case of adaptation work in the evolution of Norwegian bioeconomy.
Sammendrag
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Forfattere
Inger Skrede Monica Hongrø Solbakken Jaqueline Hess Carl Gunnar Fossdal Olav Aaseth Hegnar Gry AlfredsenSammendrag
The aim of this study was to investigate differential expression profiles of the brown rot fungus Rhodonia placenta (previously Postia placenta) harvested at several time points when grown on radiata pine (Pinus radiata) and radiata pine with three different levels of modification by furfuryl alcohol, an environmentally benign commercial wood protection system. The entire gene expression pattern of a decay fungus was followed in untreated and modified wood from initial to advanced stages of decay. The results support the current model of a two-step decay mechanism, with the expression of genes related to initial oxidative depolymerization, followed by an accumulation of transcripts of genes related to the hydrolysis of cell wall polysaccharides. When the wood decay process is finished, the fungus goes into starvation mode after five weeks when grown on unmodified radiata pine wood. The pattern of repression of oxidative processes and oxalic acid synthesis found in radiata pine at later stages of decay is not mirrored for the high-furfurylation treatment. The high treatment level provided a more unpredictable expression pattern throughout the incubation period. Furfurylation does not seem to directly influence the expression of core plant cell wall-hydrolyzing enzymes, as a delayed and prolonged, but similar, pattern was observed in the radiata pine and the modified experiments. This indicates that the fungus starts a common decay process in the modified wood but proceeds at a slower pace as access to the plant cell wall polysaccharides is restricted. This is further supported by the downregulation of hydrolytic enzymes for the high treatment level at the last harvest point (mass loss, 14%). Moreover, the mass loss does not increase during the last weeks. Collectively, this indicates a potential threshold for lower mass loss for the high-furfurylation treatment. IMPORTANCE Fungi are important decomposers of woody biomass in natural habitats. Investigation of the mechanisms employed by decay fungi in their attempt to degrade wood is important for both the basic scientific understanding of ecology and carbon cycling in nature and for applied uses of woody materials. For wooden building materials, long service life and carbon storage are essential, but decay fungi are responsible for massive losses of wood in service. Thus, the optimization of durable wood products for the future is of major importance. In this study, we have investigated the fungal genetic response to furfurylated wood, a commercial environmentally benign wood modification approach that improves the service life of wood in outdoor applications. Our results show that there is a delayed wood decay by the fungus as a response to furfurylated wood, and new knowledge about the mechanisms behind the delay is provided.