Your search resulted in 58 documents. Displaying 25 entries per page.
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
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
The use of X-ray diffraction for analyzing biomodification of crystalline cellulose by wood decay fungi
2007 - IRG/WP 07-10622
X-ray diffraction (XRD) is based on the creation of an interference pattern by x-rays when they encounter a regularly spaced matrix. In wood, this process has been used to determine, among other things, the average width of the cellulose microcrystals, the percent of crystalline cellulose within the wood, and can be used to examine the changes in these parameters during degradation. Enhanced under...
C Howell, A C Steenkjær Hastrup, J Jellison
A novel cellulose-binding domain from the brown-rot fungus Gloeophyllum trabeum
2023 - IRG/WP 23-11019
Wood-rotting basidiomycetes are the major organisms decomposing wood in nature. They are classified into two groups based on their decay modes; white-rot fungi and brown-rot fungi. White-rot fungi secrete various cellulolytic enzymes during the wood degradation process. The enzymes are known to be often appended with a cellulose binding domain (CBD) which assists the activity of catalytic domain. ...
Y Kojima, N Sunagawa, M Aoki, M Wada, K Igarashi, M Yoshida
The cellulose binding mechanism of a novel cellulose binding domain from the brown-rot fungus Gloeophyllum trabeum
2023 - IRG/WP 23-11021
In nature, wood decay is caused by various wood-rotting basidiomycetes. Wood-rotting basidiomycete are mainly divided into white-rot fungi and brown-rot fungi. Their main carbon source is cellulose of the wood cell wall during wood decay, and they produce a variety of enzymes to decompose cellulose. The cellulolytic enzymes often possess a cellulose binding domain (CBD) as an additional domain con...
M Aoki, Y Kojima, M Wada, M Yoshida
A novel cellulose-binding domain from the brown-rot fungus that can be used to evaluate cellulose in wood
2024 - IRG/WP 24-11046
Wood-rotting basidiomycetes are the primary microorganisms that decay wood in nature. They are classified as white-rot fungi and brown-rot fungi by the difference in decaying types. White-rot fungi secrete a variety of cellulolytic enzymes during wood degradation. These enzymes often have an additional cellulose-binding domain (CBD) that adsorbs to the cellulose surface and localizes the catalytic...
Y Kojima, N Sunagawa, S Tagawa, T Hatano, S Nakaba, M Aoki, M Wada, K Igarashi, M Yoshida
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...
J Bjurman
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
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
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
Contribution of wood components on the absorption of copper amine
2000 - IRG/WP 00-30216
The contribution of wood components on the absorption of copper amine was investigated. Holocellulose, lignin and xylan absorbed significant amount of copper. The amount of copper absorbed by cellulose was almost negligible. The removal of extractive also decreased the amount of copper absorption. This study clearly indicates the importance of lignin, hemicellulose in the absorption of copper amin...
D P Kamdem, Jun Zhang
Defining fungal decay types - Final proposal
1988 - IRG/WP 1355
The term soft rot is proposed for all forms of decay caused by Ascomycetes and non-basidiomyceteous Fungi imperfecti. The terms brown rot and white rot should be used only for decay caused by Basidiomycetes. Brown rot is characterized by extensive depolymerization of the cellulose and limited lignin degradation. White rot is characterised by significant degradation of the lignin component in wood....
T Nilsson
Non-enzymatic Gloeophyllum trabeum decay mechanisms: Further study
2001 - IRG/WP 01-10395
Information will be presented on the mechanisms involved in, and potential application of, non-enzymatic wood decay by brown rot decay fungi. Specifically, the hypothesized role of low molecular weight phenolate derivatives will be discussed in relation to non-enzymatic degradation of wood. The mechanism of binding of iron by cellulose, and binding and reduction of iron by fungal derivatives and m...
B Goodell, J Jellison
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
A novel defaunation method of the protozoa to investigate cellulose metabolism in Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)
1994 - IRG/WP 94-10050
The largest protozoa in the hindgut of workers of Formosan subterranean termite, Coptotermes formosanus Shiraki, was selectively eliminated by forced-feeding on low-molecular weight cellulose (LC) with a mean DP of 17. Although one week's feeding on LC caused perfect disappearance of Pseudotrichonympha grassii Koidzumi, the selective defaunation method itself had no detrimental effect on ...
T Yoshimura, K Tsunoda, M Takahashi
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
An electron spin resonance study of manganese changes in wood decayed by the brown-rot fungus, Postia placenta
1988 - IRG/WP 1359
Electron spin resonance (ESR) spectrometry was used to examine wood decay by the brown-rot fungus, Postia placenta. Wood slivers of Douglas-fir, white fir, redwood, sweetgum and yellow poplar were incubated for 4 weeks in custom-made quartz ESR tubes with or without Postia placenta. In all wood species without fungus, a weak partially resolved signal (about g=2, presumably due to manganese) was de...
B Illman, D C Meinholtz, T L Highley
Natural weathering of wood in a sunny climate effects on surface chemistry and paint adhesion
1997 - IRG/WP 97-20109
Radiata pine veneers and blocks were exposed to natural weathering under Australian summer conditions over a period of 30 days. Infrared spectroscopy revealed that there was perceptible surface delignification after 4 hours exposure, substantial surface delignification after 3 days exposure and almost complete surface delignification after 6 days. Viscometry determinations on holocellulose samples...
P D Evans, P D Thay, K J Schmalzl
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
Soft rot decay in acetylated wood. Chemical and anatomical changes in decayed wood
2002 - IRG/WP 02-40231
Acetylated Beech (Fagus sylvatica) and Scots Pine (Pinus sylvestris) wood were studied in soil beds under laboratory conditions for longer periods. High mass losses and dynamic MOE losses were measured in non-acetylated wood and at lower weight percent gains (WPG). Rapid losses of lignin, holocellulose and ?-cellulose occurred in non-acetylated beech wood and no losses were detected at the highest...
B Mohebby, H Militz
Preservative effect of cellulose insulation material against some mould fungi and brown rot fungus Coniophora puteana in pine sapwood
1991 - IRG/WP 1484
The influence of mineral wool and loose-fill cellulose wool on biodeterioration of pine sapwood was studied. The test fungi were mould fungi Aspergillus versicolor, Cladosporium sphaerospermum, Penicillium sp. and Aureobasidium pullullans and brown rot fungus Coniophora puteana. Cellulose wool inhibited the growth of mould fungi on the face of wood contacted with insulation material at RH of 97 an...
H Viitanen
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
Biochemical relationships between biodegradation of cellulose and formation of oxalic acid in brown-rot wood decay
1991 - IRG/WP 1472
Non-enzymic hydrolysis of cellulose with low concentrations of oxalic acid was examined. The incubation of pine wood pulp with 1% oxalic acid (pH 1.3) at 35°C for 4 weeks reduced the original viscosity to 60%. Reducing sugars were liberated from various cellulosic samples by the oxalic acid treatment. However, crystallinities of cellulose in those samples did not change before and after the treat...
M Shimada, Y Akamatsu, A Ohta, M Takahashi