Your search resulted in 62 documents. Displaying 25 entries per page.
Quantification of wood decay effects by HPLC analysis
1992 - IRG/WP 92-1576
The present work quantified the effects of the white rot basidiomycetes Coriolus versicolor and Phanaerochaete chrysosporium, and also those of the brown rot fungi Coniophora puteana and Lentinus lepideus, on Pinus patula and Eucalyptus grandis. Wood colonisation was quantified by Kjeldahl nitrogen determinations converted to biomass assays, and degradation was quantified by weight losses produced...
V Singh, M Tarin, G D Shelver, A A W Baecker
The metabolism and comparative elimination of polychlorinated biphenyl congeners in termites
1993 - IRG/WP 93-10038
Termites may serve as a potential supplementary food source for fish, poultry and pigs. Waste paper may be used as a source of food in mass rearing the termites. However, paper products and printing inks contain trace levels of toxic xenobiotics e.g. polychlorinatecl biphenyls (PCBs) and dioxins. This study examined the ability of Mastotermes darwinensis and Coptotermes acinaciformis to metabolise...
V S Haritos, J R J French, J T Ahokas
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
Breakdown of cellulose derivatives by cellulolytic enzymes. I. Action of fungal ß-glucosidases toward substituted PNP ß-D-glucopyranosides
1998 - IRG/WP 98-10281
The action of fungal ß-glucosidases on the methyl derivatives of p-nitrophenyl (PNP) ß-D-glucopyranoside, which were regioselectively substituted at 0-2, 0-3, 0-4 and 0-6 positions was studied. Several ß-glucosidases from brown-rot, white-rot, and soft-rot fungi and almond were used for the study. These ß-glucosidases did not act on the 2, 3, and 4-0-methyl derivatives, while the 6-0-methyl on...
T Nishimura, I Momohara, M Ishihara
Fruitbody formation and basidiosporogenesis by the white rot fungus Pycnoporus cinnabarinus
1988 - IRG/WP 1348
Conditions for fruitbody formation by the white rot fungus Pycnoporus cinnabarinus in vitro were outlined. A marked difference in substrate requirements in comparison to previously tested brown rot fungi was revealed. Agar media containing Walseth cellulose and NH4 tartrate at 1 g/l permit profound production of basidiospores particularly at 15°C but only under light treatment. Higher NH4 tartrat...
J Bjurman
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
Weathering of copper-amine treated wood
2000 - IRG/WP 00-40155
Copper ethanolamine (Cu-EA) treated southern pine (SP) were artificially weathered with a QUV Weathering Tester. The weathering regime was composed of a continuous UV-light irradiation for 2 hours followed by a water spray for 18 minutes for a total time of 1200 hours. The changes on the surface of the weathered samples were characterized by Fourier transform infrared spectroscopy (FTIR) analysis,...
J Zhang, D P Kamdem
Solid state NMR study on pine wood degraded by brown rot fungus Gloeophyllum trabeum
1994 - IRG/WP 94-10067
Blocks of Pinus koraiensis wood were degraded by Gloeophyllum trabeum and examined by solid-state 13C NMR spectroscopy. Chemical compositions were estimated from relative signal aras. There was no evidence for preferential degradation of the noncrystalline cellulose which accounted for about 4% by weight of the wood. Loss of partly ordered cellulose on crystal surfaces exceeded the loss of crystal...
Yoon Soo Kim, R Newman
The use of selective media for studying the colonization of wood in ground contact by microorganisms
1978 - IRG/WP 186
In October1976 a field trial was set up in order to monitor the progressive colonisation of wood in ground contact using orientated small stakes of Scots pine (Pinus sylvestris) and birch (Betula sp.) (30 x 45 x 250 mm³). Half the number of each species were treated with a 1% solution of CCA by a vacuum impregnation process. All the stakes were coated on three sides with an epoxy-resin sealant to...
C P Clubbe
Extracellular osmiophilic particles in connection with brown rot and white rot
1982 - IRG/WP 1157
The way of attack on Pine woodblocks of two brown-rot fungi (Fomitopsis pinicola, Coniophora puteana) differing in their cellulase activities, and one white-rot fungus (Trametes hirsuta) has been investigated by transmission electron microscopy. Even at early stages of decay, osmiophilic particles were found with all the fungi investigated. In the brown-rotted wood, the osmiophilic particles occur...
K Messner, H Stachelberger
Oxalic acid metabolism of Postia placenta
1992 - IRG/WP 92-1566
The oxalic acid metabolism of Postia placenta was studied in liquid culture in order to identify the metabolic pathways of biosynthesis and to determine whether oxalic acid physiology could be correlated with efficiency in wood decay. Oxalic acid production was determined for test strain MAD698 grown in a basal defined medium with a variety of different carbohydrate and nitrogen sources. The highe...
J A Micales
FTIR characterization of copper ethanolamine - wood interaction
1999 - IRG/WP 99-20154
The interaction of copper ethanolamine (Cu-EA) and wood components was studied by using Fourier transform infrared spectroscopy (FTIR). In Cu-EA treated wood, significant reduction was noticed on the band attributed to carbonyl vibration from carboxylic groups at 1735±5 cm-1 and an increase in band intensity was obtained from carbonyl in carboxylate at 1595±5 cm-1. The same observation was made ...
Jun Zhang, D P Kamdem
The examination of preservative-treated radiata pine using electron spin resonance spectroscopy
1987 - IRG/WP 3423
Electron spin resonance spectroscopy (ESR) may be used to characterise the molecular environment of chemical species containing unpaired electrons. These species include free radicals, bi-radicals, point defects in solids, localised crystal imperfections and many transition metal ions. ESR has previously been applied to the examination of wood weathering or wood pyrolysis and now FRI and Massey Un...
D V Plackett, E W Ainscough, A M Brodie
Protection of cellulose string with biocide/water repellent mixtures
1997 - IRG/WP 97-30148
Protecting cellulosic materials in soil contact poses a formidable challenge. Many soil inhabiting bacteria and fungi that cannot degrade wood can nevertheless rapidly depolymerize cellulose once its protective lignin matrix is removed. As a result, cellulose based materials are rarely used in direct contact with soil. One exception, however, is the use of cellulose string to support climbing vine...
A B Chang, J J Morrell
Defining fungal decay types - A proposal for discussion
1985 - IRG/WP 1264
The present definitions of the fungal decay types, white rot, brown rot, and soft rot are somewhat vague. The definitions are based on a mixture of criteria involving morphological and chemical aspects of decay as well as taxonomic affiliation of the responsible fungal species. The present vague definitions have led some fungi being erroneously places in a wrong decay type. Furthermore, some fungi...
T Nilsson
The action of siderophores isolated from Gloeophyllum trabeum on the structure and crystallinity of cellulose compounds
1991 - IRG/WP 1479
Low molecular weight, high affinity iron-binding compounds (siderophores) were isolated from the brown-rot fungus Gloeophyllum trabeum. The compounds were shown to be inducible by iron starvation and could be purified by ultra-filtration, ethyl acetate extraction, column chromatography and preparative HPLC. The isolated compounds were shown by analytical and immunological techniques to be produced...
J Jellison, V Chandhoke, B Goodell, F Fekete, N Hayashi, M Ishihara, K Yamamoto
Extracellular carbohydrate production by isolates of Postia (=Poria) placenta
1989 - IRG/WP 1388
A monokaryotic strain of Postia (=Poria) placenta, ME20, which is unable to degrade wood, also failed to produce extracellular polysaccharide when grown in liquid culture, regardless of carbon source or concentration. Other isolates of Postia placenta, including another monokaryon and a hybrid of this monokaryon with ME20, produced large quantities of this material. The polysaccharide consisted pr...
J A Micales, A L Richter, T L Highley
The resistance of wood coated with different water-borne paints against colonisation by decay fungi
1996 - IRG/WP 96-10165
The susceptibility of wood painted with model paints of known composition to decay fungi was tested without previous weathering. Included in the study were five alkyd emulsion paints and five acrylic paints; one linseed oil paint and two solvent-borne alkyd paints. It was found that several components influenced the susceptibility of these paints. The results of the present study indicate that the...
J Bjurman
The role of oxalic acid in short fiber formation by the brown-rot fungus Postia placenta
1993 - IRG/WP 93-10028
The mechanism by which brown-rot fungi depolymerize wood and cellulose remains a perplexing problem. Current evidence favors oxidation by low-molecular weight, non-enzymatic fungal metabolites. During attack of cotton cellulose by Postia placenta MAD-698, the degree of polymerization (DP) decreases to limit of degree of polymerization (LODP) over a period of 5-6 weeks with relatively low weight lo...
F Green III, J M Hackney, C A Clausen, M J Larsen, T L Highley
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
Wood plastic composites from modified wood. Part 3. Durability of WPCs with bioderived matrix
2008 - IRG/WP 08-40423
The decay resistance of fully bio-derived wood plastic composites, WPCs, was tested in both laboratory and field tests. The laboratory tests were performed according to modified versions of AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils) and the field tests according to EN 252 (stakes in ground) and EN 275 (resistance to marine borers). The WPC materials for laboratory tes...
M Westin, P Larsson Brelid, B K Segerholm, M Van den Oever
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
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