Your search resulted in 228 documents. Displaying 25 entries per page.
The effect of chitosan on the growth and physiology of two wood inhabiting fungi
2006 - IRG/WP 06-10590
The effect of chitosan on the wood inhabiting fungi Sphaeropsis sapinea and Trichoderma harzianum was evaluated at cellular level. Increasing concentrations of chitosan caused an increase in the amount of peroxide in cultures of S. sapinea, which was accompanied by a simultaneous decrease in superoxide. The same effect was not observed in T. harzianum. The growth of both fungi was inhibited when h...
D Vesentini, T Singh
Exposure of CCA and ACZA treated parallel strand lumber to marine borer attack in northeastern and southeastern waters of the United States of America
2006 - IRG/WP 06-30400
Southern pine and Douglas fir Parallel Strand Lumber (PSL) panels were treated with chromated copper arsenate (CCA) or ammoniacal copper zinc arsenate (ACZA), respectively and exposed in a marine environment in Massachusetts (northeastern USA coast) for 7 years. Similarly treated panels were also exposed to a site on the Atlantic coast Florida (southeastern USA) for the same period. In the northe...
B Goodell, P Merrick, J Jellison, Y Qian
Investigation of new wood preservation formulations based on synergies between antioxidant, 2-HPNO and Propiconazole
2006 - IRG/WP 06-30401
Wood degradation by fungi is a complex phenomenon taking place in part through oxidative reactions involving many oxidizing agents like free radicals and hydroperoxide. In order to develop novel and more environmentally benign preservative systems, mixtures of Propiconazole and antioxidants with different stabilization mechanisms were investigated to detect possible synergies allowing to reduce th...
B Bakhsous, S Dumarçay, E Gelhaye, P Gérardin
The Effect of Flavonoids on Colour and Spectral Changes of the Wood Surface Caused by Heat Treatment or Ultra-violet Irradiation
2006 - IRG/WP 06-40341
Both heat treatment and UV irradiation can cause discolouration and change in the spectral properties of wood surface. Some of the characteristic flavonols have significant role on colour and spectral changes, despite of their relative small quantities in wood.
Colour changes and spectral properties of natural and extracted black locust (Robinia pseudoacacia L.) and poplar (Populus nigra L.) were...
R Csonka-Rákosa, L Molnár-Hamvas, E Börcsök, J Molnár, K Németh
Phenol oxidase activity and one-electron oxidation activity in wood degradation by soft-rot deuteromycetes
2007 - IRG/WP 07-10615
Wood degradation, one-electron oxidation activity as assayed by ethylene generation from 2-keto-4-thiomethylbutyric acid (KTBA), and phenol oxidase activity were measured in cultures of six deuteromyce fungi, with glucose or wood as the carbon source. The four fungi that degraded Japanese beech wood had higher one-electron oxidation activities in wood-containing cultures than in glucose-containing...
H Tanaka, M Yamakawa, S Itakura, A Enoki
Gypsum effects on ‘dry rot’ wood degradation as a function of environment
2007 - IRG/WP 07-10624
‘Dry rot’ fungi are a unique group of brown rot fungi that can degrade wood away from ground contact where other fungi fail to colonize. Successfully occupying this niche is partially due to efficient water and nutrient transport, but mobilizing elements, notably calcium (Ca) and iron (Fe), from adjacent building materials has also been implicated in their success. Here we report a series of t...
J Schilling, J Jellison
Photo-degradation of modified and non-modified wood, coated with water borne acrylic coatings during artificial light exposure
2007 - IRG/WP 07-30416
A series of experiments were carried out to investigate photo-degradation of thermally modified (at 210oC and – 0.9 bars for two hours) and non-modified spruce wood (Picea abies L (Karst)), coated with transparent and semitransparent (with 3% pigment content) acrylic coatings during artificial UV light irradiation for 200 hours. Photo-degradation was evaluated in terms of colour changes througho...
M Deka, M Tomažic, M Petric
Oxidative stress and lignin peroxidase production in Phanerochaete chrysosporium
2008 - IRG/WP 08-10655
In Phanerochaete chrysosporium liquid cultures, the induction of lignin peroxidases is directly related to accumulation of reactive oxygen species at the mitochondrial level. In this study, we demonstrate that the expression of the mitochondrial thiol-related antioxidant system is not directly coupled to the LiPs expression. When the antioxidant systems are not able to cope with ROS accumulation, ...
M Morel, L Diss, C Fourrey, M Chalot, M Droux, J P Jacquot, E Gelhaye
Heat treatment, thermal treatment, thermal degradation of wood, carbon nanotubes and Damascus steel swords. What do they all have in common?
2008 - IRG/WP 08-40399
Thermal degradation of wood is a well known phenomenon. Yet heat-treatment of wood can also provide protection for wood against certain environmental hazards. This paper explores some of the aspects of thermal degradation of wood fiber at relatively low temperatures with a surprising result. Carbon nanotubes (CNTs) were produced when a specific heating regime was used to carbonize the wood fiber. ...
Xinfeng Xie, B Goodell, Yuhui Qian, G Daniel
Degradation of polychlorinated organic biocides by the wood decaying fungi
2008 - IRG/WP 08-50253
Organochlorine biocides such as lindane, pentachlorophenol sodium salt, and polychlorinated biphenyl 153 have been widely used as wood preservatives. Due to their low degradability by soil bacteria, treated waste wood products pose a serious threat to the environment. Consequently, there is an increased need for development of new strategies for their detoxification. In this work, the bioremediati...
I Vidic, L Zupancic-Kralj, K Sepcic, F Pohleven
Aislamiento, identificación y evaluación enzimática de hongos de pudrición de madera de la Región de los Lagos
2008 - IRG/WP 08-10680
So far, systematic investigations have not been developed to determine the fungal diversity associated with wood in Chile. In addition, little is known about the mycoflora capabilities or their enzymatic processes in biotechnology although different research has hinted at the great potential of these microorganisms in various industrial processes. The aim of this work is to isolate, identify and e...
R Ortiz, J Navarrete, C Oviedo, R Blanchette
The involvement of hydroxyl-radical-producing glycoprotein from the white-rot basidiomycete Ceriporiopsis subvermispora in wood decay
2009 - IRG/WP 09-10688
White-rot decay can be divided into two subtypes. One type involves the simultaneous degradation of all wood components through the formation of erosion troughs with a progressive thinning of wood cell walls. This type of decay is consistent with a model in which several polymer-degrading enzymes act on the exposed surfaces of the wood cell walls, producing progressive erosion from the lumen to th...
H Tanaka, Y Inoue, T Morikawa, S Itakura, A Enoki
Antinomic natural self-protection mechanism in long-lasting woods: a case study with three tropical species from French Guiana
2009 - IRG/WP 09-10696
We demonstrate in this work through 3 examples that Amazonian trees may specialize long-lasting woods by means of at least to different approaches. Wallaba impregnates its wood with large amounts of weakly antifungal compounds acting in synergy, while tatajuba and louro vermelho woods are naturally impregnated with antifungal agents. Comparison of biological activities in vitro and concentrations ...
A Rodrigues, M Royer, N Amusant, J Beauchêne, G Herbette, V Eparvier, A Thibaut, L Salmen Espíndola, B Thibaut, D Stien
Postia placenta gene expression of oxidative and carbohydrate metabolism related genes during growth in furfurylated wood
2009 - IRG/WP 09-10701
A range of studies the last decade have shown that modified wood can provide excellent protection against a range of wood deteriorating organisms, including decay fungi. However, we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward e.g. inhibition of action of specific enzymes, but they still need testing. An understandi...
G Alfredsen, C G Fossdal
Degradation of wood veneers by Fenton’s reagents: effects of low molecular weight phenolic compounds on hydrogen peroxide decay and tensile strength loss
2009 - IRG/WP 09-20400
Pine wood (Pinus sylvestris) veneers strips were incubated in acetate buffer containing hydrogen peroxide and iron to mimic mechanisms of brown rot decay and assess the degradation of cellulose through analysis of the tensile properties of the decayed wood. The tensile properties of thin wood strips treated with Fenton system reagents or precursors were determined and correlated to weight loss as ...
Yanjun Xie, R Well, Zefang Xiao, B Goodell, J Jellison, H Militz, C Mai
Fungal Attack on Lignin and Cellulose: Elucidation of Brown- and White-Rot Mechanisms Comparing Biomimetic and In-Vivo Degradation Patterns
2010 - IRG/WP 10-10714
This paper examines research and hypotheses that have been developed over several years on wood degradation mechanisms. This information is combined with new data and analyses to explain why wood decay patterns caused by brown-rot fungi and specific types of white-rot fungi are different. New data, including work with both biomimetic studies on low molecular weight compounds, degradative enzymes, ...
V Arantes, B Goodell, A M F Milagres, Yuhui Qian, T Filley, J Jellison, S Kelley
Chemical mediated depolymerization of cotton cellulose for the understanding of non-enzymatic fungal decay
2010 - IRG/WP 10-10731
Small, low molecular weight non-enzymatic compounds have been linked to the early stages of brown rot decay as the enzymes involved with holocellulose degradation are found to be too large to penetrate the S3 layer of intact wood cells. The most pronounced of these which were analyzed in this study are hydrogen peroxide, iron, and oxalic. The compounds related to the Fenton reaction: the combinati...
A C Steenkjær Hastrup, B Jensen, F Green III
Glutathione transferases as functional biomarkers of wood degradation?
2010 - IRG/WP 10-10735
The recent release of several fungal genome sequences allows the report of an overview of fungal glutathione transferases (GSTs) focused on their function in the wood-degrading basidiomycete Phanerochaete chrysosporium. A genomic and phylogenetic analysis of GST classes in various sequenced fungi –zygomycetes, ascomycetes and basidiomycetes- revealed some specificity in GSTs distribution, in com...
E Gelhaye, M Morel
Simulation and Investigation of Wood Degradation by Erosion Bacteria in Laboratory Experiments
2010 - IRG/WP 10-20431
A Microcosm experiment was successfully set up to establish, monitor and manipulate bacterial wood degradation under low oxygen conditions. Sound pine sticks were placed in waterlogged sediment from a heavily decayed pine pile foundation site in Amsterdam. The system was subject to different gassing treatment regimes in order to investigate the role of oxygen in the bacterial degradation process o...
J Gelbrich, E I Kretschmar, N Lamersdorf, H Militz
Degradation of Carbon-Based Preservatives by Black-stain Fungi
2010 - IRG/WP 10-30533
Some black-stain fungi are known to exhibit resistance to carbon-based preservatives. However, the cause of this resistance is unclear. The fungi may have mechanisms to tolerate these chemicals, or they may be able to degrade and detoxify them. Fungi capable of degrading carbon-based preservatives are of interest for possible bioremediation of carbon-based preservative-treated wood at the end of i...
R Stirling, P I Morris
Biological degradation of acetylated wood after 18 years in ground contact and 10 years in marine water
2010 - IRG/WP 10-40522
This paper addresses the resistance to biological degradation of acetylated wood.
Firstly, it presents results from an EN 252 test after 18 years’ exposure. The test is still running in Nordic NWPC test fields, Simlångsdalen in Sweden and Viikki in Finland. Results from this test were presented after 5 years’ exposure ( IRG/WP 97-30139), and showed that the resistance of acetylated wood wit...
P Larsson Brelid, M Westin
The effects of acetylation level on the growth of Postia placenta
2011 - IRG/WP 11-10751
To understand the defence mechanisms utilized by decay fungi when exposed to different wood protection systems the study of gene expression can give us some answers. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by differen...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
Utilization of thermodesorption coupled to GC-MS to study kinetics of thermodegradation of different wood species
2011 - IRG/WP 11-40559
Thermdesorption coupled to Gas Chromatography coupled to Mass Spectroscopy (TD-GC-MS) has been investigated to identify volatile degradation products generated during wood heat treatment by mild pyrolysis. For this purpose, wood samples of different softwood and hardwood species have been heat treated under nitrogen for different temperatures comprised between 180 and 230°C during 15 min. in the ...
K Candelier, M Chaouch, S Dumarçay, A Pétrissans, M Pétrissans, P Gérardin
In-situ experimental treatment and consolidation of degraded timber elements from a XIX century building
2012 - IRG/WP 12-10767
This paper presents the in situ experimental conservation work performed on three timber structural elements from a XIX century building: two floor beams and one roof beam. The palace was built in 1877 in the centre of Lisbon initially with residential purposes. It has four floors, with timber structural horizontal elements, stairs and roof beams (generally of Pinus sylvestris L.). The exterior wa...
D F Henriques, J de Brito, L Nunes
Wood decay enzymatic ability of Fusarium circinatum
2012 - IRG/WP 12-10777
There exists pathogens that attack standing trees of forests, and do not usually thrive once the tree is felled. However, occasionally they can be present in a latent state in the wood and can spread and affect new areas with economic, ecological and social consequences. Fusarium circinatum is a fungus that causes “pitch canker” in pine species, and is considered a quarantine organism within t...
M T Troya, F Llinares, Y Serrano, M Conde