Your search resulted in 54 documents. Displaying 25 entries per page.
Identification of terminal structures in cellulose degraded by the brown-rot fungus Postia placenta
1989 - IRG/WP 1389
To gain insight into the biochemical mechanism employed by brown-rot fungi to depolymerize cellulose, we identified the end-groups of chemically pure cellulose that had been depolymerized by the brown-rot fungus, Postia placenta. The depolymerized cellulose was acid hydrolyzed and the anion fractions isolated by ion chromatography. Sugar acids were identified by gas chromatographic and mass spectr...
T K Kirk, T L Highley, R E Ibach, M D Mozuch
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Reaction of osmium tetroxide with a diphenolic compound as a model substance for demethylated lignin
1986 - IRG/WP 1303
By using caffeic acid as a model substance for diphenolic moieties of demethylated lignin it was found that electron dense particles called by the authors "osmiophilic particles" in former papers are reaction products of OsO4 with the model substance. By these products it is possible to indicate the enzymatic demethylation of lignin taking place during wood decay. The appearance of the electron de...
K Messner, E Srebotnik
Fenton's reagent as a modification tool in brown-rot decay
1996 - IRG/WP 96-10155
A biomimetic approach was used to clarify the role and importance of the Fenton-type reaction in the carbohydrate degradation by brown-rot fungi. Spruce sawdust and microcrystalline cellulose were modified in the H2O2/Fe(II) treatment. The degree of hydrolysis of the pretreated spruce sawdust was clearly increased with the complete cellulase (Econase), purified endoglucanase from Trichoderma reese...
M Rättö, A-C Ritschkoff, J Buchert, L Viikari
Chelator production and cellobiose dehydrogenase activity of wood inhabiting fungi
2000 - IRG/WP 00-10363
Multiple components have been postulated to be involved in the Fenton-based biological degradation of wood by brown rot fungi. Chelators have been implicated in essential iron reduction steps. Cellobiose dehydrogenase activity and quinone reducing activity have also been implicated in brown rot biodegradation. When biochelator production by three white rot fungi, three brown rot fungi and three wo...
Weihong Qi, J Jellison
Regulation of hyphal sheath formation iron-chelator production by the brown rot fungi Gloeophyllum trabeum and Postia placenta
1994 - IRG/WP 94-10074
Hyphal sheath formation and iron-chelator production by liquid cultures of the brown rot fungi Gloeophyllum trabeum and Postia placenta were monitored over time. The effects of incubation at various temperatures, pH's and concentrations of iron, manganese and nitrogen were determined. Hyphal sheath production was observed microscopically and quantified with JAVA video analysis. The hyphal...
Y Chen, J Jellison
Appendage-mediated attachment in spores of lignicolous marine fungi
1982 - IRG/WP 487
The role of appendages in aiding attachment and entrapment of marine fungal spores to wood substrata is described in this paper. Scanning electron microscope (S.E.M.) observations indicated five different classes of attachment or entrapment response in the sixteen species examined. These responses varied -hith the degree to which appendages attached or entrapped spores to wood surfaces. In additio...
G Rees
A diffusion and reaction model for the leaching of Cr-VI from unfixed CCA-treated wood
2001 - IRG/WP 01-50169
A physical model applicable to the leaching of any substance undergoing a first-order fixation reaction with wood is presented. Using this model and a laboratory leaching experiment with small wood samples immersed in water, the radial and tangential diffusion coefficients and the reaction rate constants of Cr-VI in unfixed CCA-treated red pine (Pinus resinosa Ait.) are measured. Reaction rate con...
L Waldron, P A Cooper
Log fumigation prevents enzyme-mediated sapwood discolorations in hardwoods
1993 - IRG/WP 93-10003
Non-microbial sapwood discolorations in hardwood lumber can cause economic loss by degrade of quality. Based on the hypothesis that the enzyme-mediated sapstain may develop in part from byproducts of parenchyma cells in wood, reshly felled logs of red oak (Quercus spp.) and sugar hackberry (Celtis laevigata) were fumigated under a plastic tarp with methyl bromide. Log sections were checked after f...
E L Schmidt, T L Amburgey
The role of oxygen and oxygen radicals in one-electron oxidation reactions mediated by low-molecular weight chelators isolated from Gloeophyllum trabeum.markup
1994 - IRG/WP 94-10086
The KTBA assay for determination of one-electron oxidation activity was used to assay reactions of low-molecular weight chelators isolated from the brown rot fungus Gloeophyllum trabeum. The assay, performed either under air or nitrogen showed that molecular oxygen was an important factor in chelator-mediated oxidation reactions. A reduction in oxidative activity was observed when superoxide dismu...
Jun Lu, B Goodell, Jiang Liu, A Enoki, J Jellison, H Tanaka, F Fekete
Amine copper reaction with wood components: acidity versus copper adsorption
1997 - IRG/WP 97-30161
The bonding sites for copper in wood from CCA, as well as ammoniacal/amine based systems, has long been a topic of investigation. Both phenolic and carboxylic functional groups have been discussed as potential bonding sites for copper. However, no consensus on the adsorption mechanism has been realized. Thus, the selective adsorption of copper in southern yellow pine from ethanolamine-copper solut...
S M Thomason, E A Pasek
Examination of preservative-treated Pinus sylvestris using electron paramagnetic resonance
1992 - IRG/WP 92-3710
EPR is currently being used to help elucidate the nature and extent of the chemical reactions occurring between wood and copper based timber preservatives. In the work reported here treated Scots pine samples were examined at room temperature and in the frozen state. Plots of the electronic parameters A|| vs. g|| were found to be a useful index of the electronic properties of the various formulati...
A S Hughes, R J Murphy, J F Gibson, A J Cornfield
A model for attack at a distance from the hyphae based on studies with the brown rot Coniophora puteana
1995 - IRG/WP 95-10104
In timber infested by brown rot fungi, a rapid loss in strength is attributed to production of hydroxyl radicals (HO·) at a distance from the hyphae. The immediate precursor is Fenton's reagent (Fe(II)/H2O2), but the pathways leading to Fe(II) and H2O2 have remained unclear. Cellobiose dehydrogenase, purified from cultures of Coniophora puteana, will couple oxidation of cellodextrins to ...
S M Hyde, P M Wood
Comparative study of lignocellulolytic activities of Pleurotus spp. and white rot and brown-rot fungi
1997 - IRG/WP 97-10209
Field and fungal cellar trials have been set up to assess the biocontrol potential of a selected Trichoderma viride isolate in a situation representative of the end use of treated timber in ground contact situations. These trials are designed to give information about the efficacy of biological control as well as the suitability of existing chemical treatment methods for use with biocontrol fungi....
H L Brown, A Bruce
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
Chemical reactions involved in furfurylation of solid wood - An investigation by ATR-IR spectroscopy
2006 - IRG/WP 06-40347
Wood modification with furfuryl alcohol (FA) has gained renewed interest during the last five to ten years because of advances in process technology and because of increased focus on the environmental hazards of traditional wood impregnation. The reaction mechanisms involved in the furfurylation process are not yet understood in detail. In the work presented here, the chemical reactions and their ...
T Mark Venås, L Garbrecht Thygesen, S Barsberg
Wood decay fungi from New Zealand ‘leaky’ buildings: PCR identification and laboratory decay tests of wood preservative-treated Pinus radiata (Part 1)
2007 - IRG/WP 07-10620
Fungi colonising Pinus radiata D. Don framing timber of ‘leaky’ New Zealand buildings were isolated to produce pure cultures. Mycelia from these cultures on agar media were collected to extract DNA. To identify the fungi to the species level, polymerase chain reaction (PCR) with primer pairs ITS1-F and ITS4 were performed followed by sequencing of the internal transcribed spacer (ITS) region. ...
D Stahlhut, R L Farrell, R Wakeling, M Hedley
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
Wood decay fungi from New Zealand leaky buildings – PCR identification (Part 2) and aerial spore trapping
2008 - IRG/WP 08-10649
Prior to this study, it was not know which species of decay fungi caused decay in New Zealand leaky buildings. Use of molecular biology methodology, polymerase chain reaction (PCR), and subsequent DNA sequencing, as well as classical mycological techniques based on morphology, has enabled identification of decay fungi and has provided insight into their relative importance based on isolation frequ...
D Stahlhut, R L Farrell, R Wakeling, M Hedley
Bi-oleothermal treatment of wood at atmospheric pressure: resistance to fungi and insects, resistance to weathering and reaction to fire results
2008 - IRG/WP 08-40418
Bi-oleothermal process is a simple treatment which has been developped by CIRAD in cooperation with FCBA. It allows a deep impregnation of wood with hydrophobic products using cheap facilities. The process includes two steps at atmospheric pressure. The first one is a dipping of wood samples in a hot oil bath (between 110 °C and 200°C) which creates an overpressure inside the wood. The second on...
L Podgorski, I Le Bayon, I Paulmier, J-D Lanvin, V Georges, D Grenier, H Baillères, J-M Méot
Serpula lacrymans – calcium, iron, and foundering wooden boats
2009 - IRG/WP 09-10691
Serpula lacrymans is one of the most destructive wood-degrading brown rot fungi in temperate environments. Its virulence has often been linked to its ability to grow over non-woody materials and extract calcium (Ca) or iron (Fe) to promote wood degradation in buildings. This fungus has also been a severe problem in historic wooden warships and in modern wooden vessels, sometimes leading to founder...
J S Schilling, S M Duncan
Protection mechanisms of modified wood against decay by white and brown rot fungi
2010 - IRG/WP 10-10713
The resistance of beech and pine wood blocks treated with 1,3-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) against T. versicolor and C. puteana increased with increasing WPG. Full protection (mass loss below 3%) was reached at WPGs of approximately 15% (beech) and 10% (pine). Metabolic activity of the fungi in the wood blocks was assessed as heat or energy production determined by isothermal mic...
C Mai, P Verma, Yanjun Xie, J Dyckmans, H Militz
Communities of mold fungi on flooded building materials
2013 - IRG/WP 13-10799
A small building built to residential code was flooded using farmland pond water to a depth of two feet at Tuskegee University. The building was drained and left enclosed for an additional three weeks. A total of 168 material samples were removed either immediately after opening (wet) or seven months after flooding (dry). Wall materials sampled included fiberglass batt insulation, gypsum wallboard...
F Skrobot III, H Aglan, S V Diehl
Durability of reaction to fire performance of FRT wood products in different end use applications – Methods and results
2015 - IRG/WP 15-40705
Fire retardant treatments (FRT) may considerably improve the reaction to fire properties of wood-based products and the highest fire classifications for combustible products can be reached, but the maintained reaction to fire performance e. g. in exterior applications needs to be addressed in order to form a basis for new and reliable wood products with improved fire performance.
A European Techn...
B Östman, L Tsantaridis
Fire protection of wooden facades in Norway
2015 - IRG/WP 15-40710
Wood products are experiencing a renaissance as construction material in Europe due to their environmental benefits. In Norwegian building design however, timber has always played an important role but has had its limitations in urban architecture. One of the reasons is a high demand to fire safety in dense house building and multi-story buildings. Though novel construction methods and fire safety...
U Hundhausen, K-C Mahnert