Your search resulted in 238 documents. Displaying 25 entries per page.
Cytochemical localization of hydrogen peroxide in brown rot fungus Tyromyces palustris by cerium chloride technique
1999 - IRG/WP 99-10299
Cerium chloride (CeCl3) was used to localize H2O2 cytochemically for studying relationship between ultrastructural and functional characteristics of cellulose degradation by brown rot fungi. This technique proved very useful in localizing discrete electron-densereactionproducts at high resolution with minimal nonspecific deposition. The cytochemical localization of extracellular H2O2 by CeCl3 usin...
Yoon Soo Kim, Seung-Gon Wi
Involvement of hydrogen peroxide in wood decay by brown-rot and white-rot fungi
1985 - IRG/WP 1256
To gain further understanding of the role of H2O2 in wood degradation by brown- and white-rot fungi, we studied the following: (a) extracellular H2O2 production, (b) effect of various hydroxyl radical (·OH) and singlet O2 (1O2) quenching agents on wood and cellulose degradation, (c) intracellular H2O2 production and catalase activity, and (d) cytochemical localization of H2O2 with diaminobenzidin...
T L Highley, L L Murmanis
Immunogold localisation of catalytic domain of endocellulase in the cellulosic substrates
1997 - IRG/WP 97-10205
The reaction of catalytic domain of endocellulase on the cellulosic substrates was visualised by using immunogold labelling procedures to obtain a better understanding of the mechanism of enzymatic cellulose hydrolysis. Polyclonal antibody was produced against the catalytic domain of endo-l, 4-ß-glucanase (EGI) from a ruminal anaerobic bacterium Ruminococcus albus F-40. Immuno-TEM works showed th...
Yoon Soo Kim, Seung-Gon Wi, Kyu Ho Myung, K Ohmiya, S Karita
Ultrastructure of degraded, CCA-treated Pinus radiata wood from a marine pile
1990 - IRG/WP 1461
During an inspection of marine piles, 12 years after installation, severe degradation was noted on one of them in the vicinity of a corroded eye-bolt. The wood was dark brown in colour and tended to crumble easily. Wood fragments were examined by light microscopy and scanning and transmission electron microscopy and were also analysed for carbohydrates and lignin. Light microscopy showed numerous ...
A P Singh, M E Hedley
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
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
Effects of alkali treatment on some mechanical and chemical properties of creosote treated oaks
1991 - IRG/WP 2366
To date, there is a lack of information on the effects of chemical treatment on the performance of creosote preservative treated oak sleepers. This factorial experiment was designed to analyze three main effects: species (Quercus alba and Quercus rubra) creosote treatment (treated and untreated), and alkali (NaOH) soaking (0, 1, and 10 percent). The modulus of elasticity (MOE) and fiber stress at ...
P Chow, A J Reinschmidt, E J Barenberg, L C Chang
Relationship between degradation of wood, cellulose or lignin-related compounds and production of hydroxyl radical or accumulation of oxalic acid in cultures of brown-rot fungi
1994 - IRG/WP 94-10062
The degradation activities of brown rot fungi against wood, cellulose, and lignin-related compounds were measured in cultures containing glucose or wood as a carbon source. Also the activities of one-electron oxidation and hydroxyl radical production and the amount of oxalic acid present in the cultures were measured. The degradation activities of the fungi against wood, crystalline cellulose and ...
S Itakura, T Hirano, H Tanaka, A Enoki
The role of oxidation in wood degradation by brown-rot fung
1992 - IRG/WP 92-1562
Brown-rot fungi are suggested to degrade cellulose by oxidation with hydrogen radicalsformed eg. in the conversion of hydrogen peroxide in the Fenton type reactions. The stuctural changes in the holocellulose in wood induced by Fenton's reaction on wood components are very similar to those caused by brown-rot fungi. In this work the effect of the Fenton reaction on wood components was stu...
A-C Ritschkoff, J Pere, J Buchert, L Viikari
Properties of cellulose degraded by the brown rot fungus, Postia placenta
1988 - IRG/WP 1350
To gain further understanding of the nature of the cellulose depolymerizing agent or agents of brown-rot fungi, brown-rotted cellulose was chemically and physically characterized. Various culture conditions, such as low nitrogen and elevated oxygen levels, did not induce degradation of cellulose by Postia placenta in liquid cultures. Therefore, brown-rotted cellulose for analysis was prepared by a...
T L Highley, R E Ibach, T K Kirk
Targeted inhibition of wood decay fungi: degradation of cotton cellulose
1999 - IRG/WP 99-10321
Brown-rot decay is responsible for 80% of the damage and replacement of wood in service. For nearly thirty years, researchers have postulated a one-electron oxidase system combining Fe+2 oxalic acid, and H2O2 in the production of hydroxy radicals which ultimately oxidize cellulose in situ. Recently, researchers have been investigating antioxicants, in combination with biocides (Schultz, et al.,199...
F Green III, T A Kuster
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
Micromorphological and chemical characteristics of waterlogged archaeological bamboos excavated from the Yellow Sea
2012 - IRG/WP 12-10785
Bamboos have widely used as documentation material in Far Eastern countries such China, Korea and Japan. In particular, bamboo slips as documentation material were extensively used even after the wide spread of paper in those countries. A large number of bamboo slips have been excavated from the shipwreck since 2009 in Korea. Understanding the cause of deterioration of ancient bamboos is crucial f...
Mi Young Cha, Yoon Soo Kim
Microbiological degradation of wooden piles in building foundations
1988 - IRG/WP 1370
White rot, soft rot and bacterial attack have been detected in softwood piles under buildings. In some cases bacteria were found to be the main degradation organisms in the studied piles. The water content of degraded piles was very high. The compression strength was quite low also in the piles deteriorated by bacteria. The density of wood was very variable, and the degree of degradation could not...
L Paajanen, H Viitanen
Fungal and bacterial attack of CCA-treated Pinus radiata timbers from a water-cooling tower
1991 - IRG/WP 1488
Transmission electron microscopy of decaying CCA-treated Pinus radiata timbers from an industrial water cooling tower showed presence of a thick biofilm covering some areas of the wood. The biofilm contained various morphologically distinct forms of microorganisms embedded in a slime. The study provided evidence of the activity of soft rot fungi and tunnelling and erosion bacteria in wood cells. T...
A P Singh, M E Hedley, D R Page, C S Han, K Atisongkroh
Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observ...
P D Evans, S Thein
Leaching of components from water-borne paints and fungitoxic effects
1995 - IRG/WP 95-20062
Water-borne model paints, acrylics and alkyd emulsion paints, of known composition were leached according to a procedure modified in accordance with ASTM 6271.1. The effectiveness of fungicidal compounds in the painted specimens before and after leaching was evaluated with a biotest in which Penicillium brevicompactum was used as a test fungus. The leaching of the fungicide Troysan Polyphase accor...
Resistance of Alstonia scholaris vestures to degradation by tunnelling bacteria
1992 - IRG/WP 92-1547
Electron microscopic examination of vessels and fibre-tracheids in the wood of Alstonia scholaris exposed to tunnelling bacteria (TB) in a liquid culture showed degradation of all areas of the secondary wall. The highly lignified middle lamella was also degraded in advanced stages of TB attack. However, vestured pit membranes and vestures appeared to be resistant to degradation by TB even when oth...
A P Singh, T Nilsson, G F Daniel
Effect of medium-term degradation of beech wood by erosive (Phanerochaete chrysosporium) and lignin-selective (Ceriporiopsis subvermispora) strains of white rot fungi on its selected physical properties
2004 - IRG/WP 04-40292
At the Faculty of Wood Sciences and Technology a fungal delignification of normal and tension beech wood by erosive and lignin-selective strains white-rot fungi has been studied. The pre-treatment of both kind of wood samples was accompanied by partial delignification and apparent changes of their physical properties influencing the polar liquids penetration....
R Solár, S Kurjatko, M Mamonová, J Hudec
A discussion of current theories concerning CCA fixation
1983 - IRG/WP 3238
The understanding of the fixation mechanism of CCA and related preservatives in wood has been greatly improved by a significant series of recent scientific papers. In view of recent concerns in New Zealand regarding the long-term efficacy of CCA in high decay-hazard situations, it was considered appropriate to review this recent work and to contrast it with theories presented by previous workers....
D V Plackett
Detoxification of preservatives: Tri-n-butyltin oxide as a biocide
1982 - IRG/WP 1156
T E Dudley-Brendell, D J Dickinson
The present classification of wood degradation factors
1994 - IRG/WP 94-10071
The revised version of classification of wood degradation factors is presented after discussion and remarks sended by IRG-Members. The classification contains the biotic and abiotic factors in two aspects: etiological and symptomatical....
Response of the Formosan Subterranean Termite (Coptotermes formosanus) to Cellulose Insulation Treated with Boric Acid in Choice and No-Choice Tests.
2004 - IRG/WP 04-10532
The tunneling ability of the Formosan subterranean termite Coptotermes formosanus Shiraki through a cellulose insulation material containing11.1% boric acid was tested in choice and no-choice bioassays. We examined tunneling behavior and mortality of termites exposed to treated and untreated insulation material in miniature simulated wall voids. In a choice test termites tunneled through untreat...
M E Mankowski, J K Grace
The influence of crystalline and amorphous cellulose on extracellular hydrogen peroxide production by brown-rot fungi
1991 - IRG/WP 1482
The production of hydrogen peroxide (H2O2) has been suggested to play a key role in the degradation of wood by wood-rotting fungi. The production of extracellular hydrogen peroxide was studied by a quantitative method which detects the oxidation of the 2,2-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) by H2O2 and horseradish peroxidase (HRP) in liquid culture medium. The carbon sources u...
A-C Ritschkoff, L Viikari
Studies of the distribution and degradation of tributyltin naphthenate in double-vacuum treated wood
1983 - IRG/WP 3230
The effects of forced solvent evaporation by kilning redwood (Pinus sylvestris) that has been double-vacuum treated with tributyltin naphthenate (TBTN) have been investigated. Contrary to previous studies reported, it has been shown that forced evaporation can have a considerable influence on the losses of the fungicide. It has been found that, whether the solvent is allowed to evaporate slowly or...
J Jermer, M-L Edlund, W Hintze, S V Ohlsson