Your search resulted in 1091 documents. Displaying 25 entries per page.
The Chelator Mediated Fenton System in the Brown Rot Fungi: Details of the Mechanism, and Reasons Why it has Been Ineffective as a Biomimetic Treatment in some Biomass Applications – a Review
2014 - IRG/WP 14-10828
The chelator-mediated Fenton (CMF) reaction requires the action of two types of chelating compounds. The first chelator, oxalate, solubilizes and then sequesters iron, and the second chelator reduces iron. Iron reduction must be controlled near the fungal hyphae to prevent damaging Fenton chemistry from occurring in that location. Similarly, iron reduction must be promoted within the wood/plant ce...
B S Goodell, M Nakamura, J Jellison
In-ground durability of wood-based products – Comparative assessment of graveyard field tests and terrestrial microcosms
2014 - IRG/WP 14-20538
Traditionally wood durability and the effectiveness of wood preservatives are determined in so-called graveyard tests (according to EN 252 or AWPA E7). For laboratory testing, terrestrial microcosms (TMC) can serve as an alternative. Both tests have been applied for different types of wood-based materials, preservative treated, modified and unmodified wood. However, the usability of laboratory res...
A Soetbeer, L Meyer, C Brischke, P Larsson-Brelid, J Jermer
Effectiveness of Copper Indicators in Treated Wood Exposed to Copper Tolerant Fungi
2014 - IRG/WP 14-20554
Wood treated with a copper based wood preservative will typically turn a green color. While the depth of copper penetration can be readily discerned from the green color of the copper it is standard practice in research and commercial treating plants to make use of a color reagent such as Chrome Azurol S, Rubeanic acid or PAN indicator to reveal the penetration more clearly. When copper treat...
L Jin, K Brown, A Zahora, K Archer
Decay resistance of wood-plastic composites reinforced with extracted or delignified wood flour
2014 - IRG/WP 14-40655
The moisture and decay resistance of wood-plastic composites (WPCs) reinforced with extracted or delignified wood flour (WF) was investigated. Three different extractions were preformed: toluene/ethanol (TE), acetone/water (AW), and hot water (HW). Delignification (DL) was performed using a sodium chlorite/acetic acid solution. All WPCs specimens were made with 50% by weight HDPE and WF, first com...
R E Ibach, Yao Chen, N M Stark, M A Tshabalala, Yongming Fan, Jianmin Gao
Development of new wood treatments combining boron impregnation and thermo modification - Effect on decay and termites durability
2014 - IRG/WP 14-40666
Environmental pressures appeared in most European countries during the last decade has lead to the development of more environmentally acceptable preservation methods. In this context, wood heat treatment has been one of the most investigated alternative methods during the last years. Treated at temperatures ranging between 180 and 220°C, wood components undergo more or less important chemical mo...
S Salman, A Pétrissans, M-F Thévenon, S Dumarçay, B Pollier, P Gérardin
Possible targets of wood modification in brown rot degradation
2014 - IRG/WP 14-40676
Wood modification protects wood from fungal degradation in a non-toxic manner. However, the mechanisms behind the decay resistance in modified wood are currently unknown. The aim of this study was to discuss the i) colonisation, ii) nutrient recognition, iii) transcription, iv) depolymerisation and v) hydrolysis steps in the brown rot degradation progress and explore whether they are inhibited by ...
R Ringman, A Pilgård, G Alfredsen, B Goodell, K Richter
Interpretation of moisture monitoring data - Relevance of moisture content thresholds for fungal decay
2015 - IRG/WP 15-10839
It is widely accepted that besides temperature wood moisture content (MC) is the key factor when it comes to durability of wooden structures exposed to weathering. Many approaches to predict the service life of wooden structures have therefore been based on using wood MC as one major input-variable to develop dose-response relationships between material climate and decay response. However, to impr...
L Meyer, C Brischke
The copper-transporting ATPase pump and its potential role in copper-tolerance
2016 - IRG/WP 16-10859
Copper-tolerant brown-rot decay fungi exploit intricate mechanisms to neutralize the efficacy of copper-containing preservative formulations. The production and accumulation of oxalate is the most widely recognized theory regarding the mechanism of copper-tolerance in these fungi. The role of oxalate, however, may be only one part of a series of necessary components required for this complex mecha...
K M Ohno, C A Clausen, F Green III, G Stanosz
Production of reactive oxygen species in the presence of oxidized iron and oxalate under conditions mimicking brown-rot fungal degradation of wood
2016 - IRG/WP 16-10861
The biochemical role of oxalate in the fungal solubilization of iron is well known, but additional information is needed on the role that oxalate plays in the brown-rot decay of lignocellulose. In this study iron sequestration from iron and iron oxide-hydroxides was assessed with regard to the function of a chelator-mediated Fenton (CMF) reaction and the generation of reactive oxygen species (ROS)...
Yuan Zhu, Liangpeng Zhuang, B Goodell, Jinzhen Cao, J Mahaney
High-frequency monitoring of mass loss due to brown rot degradation of modified wood
2016 - IRG/WP 16-10862
Fungi growing in liquid culture undergoes three separate phases in which they i) adapt to the new environment, ii) grow unrestrictedly and exponentially, and iii) are inhibited to increase in number/mass due to lack of nutrients etc. Filamentous fungi have been shown to exhibit similar growth phases in a solid food substrate and have been modelled to grow in this way also in solid wood. In modifie...
R Ringman, A Pilgård, K Richter
Fungicidal Effect of Tobacco Stalks (Nicotiana tabacum L.) Against Brown Rot Fungi “Coniophora puteana”
2016 - IRG/WP 16-10865
In this study it was investigated that the fungicidal effect of tobacco plant (Nicotiana tabacum L.), which is grown in many countries of the world, against brown rot fungi “Coniophora puteana”. The protective effect of this plant on Scotch pine (Pinus sylvestris L.) wood was considered by means of fungi decay test (EN 113). The wood samples have been treated by five different extracts; at 3%,...
Ü C Yıldız, S Yıldız, A Yılmaz, S Durmaz
Resistance of heat treated Ash wood under steam pressure: rot fungi, soil micro-organisms and termites
2016 - IRG/WP 16-40724
Thermal modification processes have been developed to increase the biological durability and dimensional stability of wood. The aim of this paper was to study the influence of ThermoWood® treatment intensity on wood decay resistance improvement against soil-inhabiting micro-organisms, brown/white rots and termite’s exposures. All of the tests were carried out in the laboratory with two differen...
K Candelier, S Hannouz, M-F Thévenon, D Guibal, P Gérardin, M Pétrissans, R Collet
Superhydrophobic treatment of Norway spruce wood for improvement of its resistance against brown rot and moulds
2016 - IRG/WP 16-40734
Water repellence of wood can be increased and its some other properties influenced by introduction of hydrophobic chemicals into and on cell walls without affecting the wood’s bulk density due to lumen filling. Herein, a simple dipping method to insert octadecyltrichlorosilane (OTS) into cell walls and to deposit the self-assembled hydrophobic monolayers (SAMs) of OTS is reported. It was found o...
A Kumar, P Ryparová, P Hajek, B Kričej, M Pavlič, A S Škapin, M Šernek, J Tywoniak, J Žigon, M Petrič
Role of cell wall specific moisture content on the brown-rot fungal attack on wood
2016 - IRG/WP 16-40736
Wood is a hydroscopic resource because the cell wall polymers contain hydroxyl and other oxygen-containing groups that attract moisture through hydrogen bonding. Moisture content varies with changing moisture content in its environment. The moisture content in wood is responsible for many of the performance properties we observe. The strength properties of wood are dependent on the moisture con...
R M Rowell
Untreated and copper-treated wood soaked in sodium oxalate: Effects of decay by copper-tolerant and copper-sensitive fungi
2017 - IRG/WP 17-10888
Copper is widely used as the primary component in wood protectants because it demonstrates a broad range of biocidal properties. However, a key concern with using copper in wood preservative formulations is the possibility for brown-rot basidiomycetes to resist the toxic effect. Many brown-rot basidiomycetes have evolved mechanisms, like the production and accumulation of oxalate, which helps thes...
K M Ohno, G T Kirker, A B Bishell, C A Clausen
Enhancing Our Understanding of Brown Rot Mechanisms through Catalytic Pretreatment and Cellulase Cocktail
2018 - IRG/WP 18-10909
A catalytic mechanism, described as the “chelator-mediated Fenton” (CMF) mechanism, is proposed to mimic the non-enzymatic action of brown rot fungi. A CMF treatment was used together with an enzymatic cocktail to study how wood was deconstructed and solubilized. This was done in-part to determine if the treatment mimicked the action of brown rot fungi, but also to explore improved treatment p...
S Tabor, L Orjuela, D Contreras, G Alfredsen, J Jellison, S Renneckar, B Goodell
Mechanism of nano metal fluorides against fungi
2018 - IRG/WP 18-30730
Metal fluoride nanoparticles are promising because of their low water solubility, which reduces the need for fixatives required in widely used active ingredient in wood preservatives such as copper and boron. Wood specimens treated with fluoride sols of MgF2 and CaF2 have been tested against brown-rot fungi (Coniophora puteana and Rhodonia placenta) in accordance with EN 113 and against termites (...
S M Usmani, K Klutzny, I Stephan, T Hübert, E Kemnitz
FTIR-ATR monitoring of chemical changes of thermo-chemically modified beech wood degraded by brown-rot fungus
2018 - IRG/WP 18-40823
Wood chemical modification with lactic acid oligomers (OLA) has been reported to confer promising properties for wood outdoors applications. To better understand the lactic acid interaction with wood, chemical changes following biological degradation have been characterized with a battery of tests. Fourier transform infrared (FTIR) spectroscopy has been proved to be a valuable tool for studying fu...
C Grosse, M Noël, M-F Thevenon, P Gérardin
Recent findings clarifying the mechanism of brown-rot decay protection in acetylated wood
2018 - IRG/WP 18-40827
This paper summarizes the findings obtained during my PhD research over the past three years. The results provide insights which help to understand the enhanced brown-rot decay resistance of acetylated wood with particular emphasis on the role of water. The protection acetylation provides is derived from moisture exclusion within the acetylated cell wall, but the exact mechanism by which water is ...
G Beck
Non-stochiometric oxidation and ROS generation promoted by guaiacol lignin structures and lignocelluose surfaces may be a component of brown rot fungal degradation mechanisms
2019 - IRG/WP 19-10937
Model guaiacol compounds representing lignin monomers, as well as DHP-lignin and wood flour of controlled particle size were used to assess iron reduction at the pH of the natural wood cell wall. All compounds functioned as electron donors for ferric iron, with the lignin monomers demonstrating capacity for non-stochiometric reduction of iron with multiple moles of ferric ion reduced per mole of l...
Y Tamarua, M Yoshidaa, L D Eltisb, B Goodell
Difference of wood decay manner between brown-rot species
2019 - IRG/WP 19-10938
Wood blocks (Cryptomeria japonica) which were decayed by a Polyporales white-rot fungus (Trametes versicolor) and brown-rot fungi (Fomitopsis palustris, F. pinicola, and Wolfiporia cocos), respectively, were analyzed by X-ray diffraction and infrared spectroscopic methods followed by multivariate analysis. In the analyses, the differences in the cellulose crystallinities and infrared spectral patt...
R Kondo, Yo Horikawa, S Nakaba, K Ando, M Yoshida
From fungal detoxification systems to wood durability in neotropical forests
2019 - IRG/WP 19-10946
White-rot fungi are able to mineralize all the wood components due in particular to an efficient detoxification system. We hypothesised that components of this detoxification systems, glutathione transferases, could be used as tools to explore the natural durability of neotropical wood species. Analysis of the interactions between six glutathione transferases of Trametes versicolor and extracts of...
T Perrot, G Salzet, N Amusant, J Duchene, E Gelhaye
Characterization of Pectinases from Brown-rot Fungus Fomitopsis palustris
2019 - IRG/WP 19-10951
Brown-rot fungi occur on softwood used as building materials and cause destructive breakdown of wood structure. Therefore, a more accurate understanding is important from the perspective of wood protection. Previous studies have reported that hyphae of brown-rot fungi go through bordered pits on tracheids when the fungi grow into softwood [Francis W.M.R.Schwarze (2007)], and torus existing in the ...
Y Tanaka, N Konno, T Suzuki, N Habu
Chemical composition, antitermite and antifungal activity of Dacryodes edulis oleoresin
2019 - IRG/WP 19-20653
Damages to wood structures and other cellulosic materials caused by wood destroying insects and fungi are estimated to several billions of dollars each year in the world. Among these, termites are considered as one of the most economically important pests for wooden structures. In the past, several wood protection chemicals like CCA, creosote, lindane or pentachlorophenol have been used. However, ...
W F Bedounguindzi, K Candelier, P E Engonga, Se Dumarcay, M-F Thevenon, P Gerardin
Hydroxyl accessibility - A brief review of deuterium exchange studies on modified wood
2019 - IRG/WP 19-20656
Wood modification imparts dimensional stability and decay resistance. The mechanism(s) by which this occurs are thought to be related to the bulking of the wood cell wall and subsequent moisture exclusion. Hence, quantification of accessible hydroxyl (OH) groups is of great interest when evaluating and increasing the understanding of the performance of modified wood. The aim of this study was to b...
G Beck, C Hill, G Alfredsen