Your search resulted in 768 documents. Displaying 25 entries per page.
Detection of a brown-rot fungus using serological assays
1986 - IRG/WP 1305
Polyclonal antisera produced to Poria placenta (Fr.) Cooke were used in two tests to qualitatively assay for the fungus. Fungal hyphae were fixed to slides and fluorescent antibody (FA) techniques used to visualize the hyphae under the microscope. Fluorescence of non-Poria fungi, when present, could be reduced but not eliminated by cross-absorbing the sera with these fungi. The antisera was also u...
B Goodell, J Jellison
Preservative ability of wood to be fixed hydroxyl apatite substituted for antimicrobial metals
2001 - IRG/WP 01-30272
We succeeded in forming hydroxy apatite (HAp) in wood. HAp is non-toxicity and safe. Preservative ability of the wood, which substituted one part of Ca of constituent element of this HA p for antibacterial metals was measured. When Ca was substituted for Ag or Zn, mass loss in decay by brown-rot fungus F. palustris was restrained in about 50% (Ag) ~30% (Zn) of value of control specimen. However, w...
Y Haruhiko, I Sumaru
Studies on the resistance of DMDHEU treated wood against white-rot and brown-rot fungi
2005 - IRG/WP 05-10566
Beech wood (Fagus sylvatica) modified with the textile finishing agent 1,3 dimethylol-4,5-dihydroxyethylen urea (DMDHEU) has shown to improve durability against the white-rot fungus Trametes versicolor. In a mini-block test, the weight loss over eight weeks of incubation decreased with increasing weight percent gain (WPG) of DMDHEU. At 25% WPG, no significant weight loss was observed, while untrea...
P Verma, C Mai, A Krause, H Militz
Influence of CCA and TnBTO on wood decay, under different oxygen levels and various initial moisture content
2001 - IRG/WP 01-10415
Fagus sylvatica (beech) and Pinus sylvestris (Scots pine) were impregnated by TnBTO (tributyl-tin oxide) and CCA (chromated copper arsenate). In wood blocks two levels of moisture content (50% and 100% of saturation point) were used. Three levels of oxygen concentrations (10, 21, and 50%) were chosen. Treated and untreated wood were exposed to three fungi (C. versicolor a white rot, C. puteana, a ...
S M Kazemi, R J Murphy, D J Dickinson
Extracellular hydrogen peroxide producing and hydrogen peroxide reducing compounds of wood decay fungi
1991 - IRG/WP 1516
Extracellular H2O2-producing and H2O2-reducing compounds were isolated from wood-containing cultures of all the white-rot and brown-rot fungi and Ascomycetes which well degraded wood, but were not detected in the culture of the fungi which degraded little wood. The compounds are glycopeptides with a low molecular weight, require H2O2 for one-electron oxidation, catalyze the redox reaction between ...
A Enoki, G Fuse, H Tanaka
Control of sapwood-inhabiting fungi by fractionated extracellular metabolites from Coniophora puteana
1991 - IRG/WP 1494
The objective of this study was to test the fractionated metabolites released by Coniophora puteana for their antagonistic activity against the sapstain fungi Ceratocystis coerulescens and Aureobasidum pullulans, and the molds Asperigillus niger and Penicillium spp. The acetone-soluble fraction obtained from the culture filtrate prepared from Coniophora puteana grown on 6% malt extract agar inhibi...
S C Croan, T L Highley
Decay resistance of densified ammonia-plasticized stems of oil palm (Elaeis guineensis)
1991 - IRG/WP 3673
When wafers of oil palm stems (Elaeis guineensis) were plasticized with 28% aqueous ammonia and immediately compressed mechanically, the treated material, gained 73% in basic density (average basic density, 0.695 g/cm³), and was highly resistant to decay by wood rot basidiomycetes. Compared with the control specimens (density, 0.403 g/cm³), resistance to decay of the densified specimens by Corio...
A H H Wong, M P Koh
Dimensional lumber model demonstrates the sensitivity of the particle capture immunoassay in early detection of brown-rot fungi
1995 - IRG/WP 95-20058
A dimensional lumber model was designed to test the sensitivity of the particle capture immunoassay (PCI) compared to traditional methods of culturing and microscopic examination for detection of brown-rot fungi. Southern yellow pine 2 x 4's (5.1x10.2 cm²), and 86.4 cm in length, were inoculated on one end with the brown-rot fungus, Postia placenta, and tested over the full length of the...
C A Clausen, L Ferge
Detection of brown-rot antigens in southern pine
1996 - IRG/WP 96-20090
Brown rot fungal antigens were detected by particle capture immunoassay (PCI) in southern pine 2 x 4's beyond visible or culturable hyphal growth. Further analysis of test samples revealed changes along the 2 x 4's that could be grouped into zones. Zone 1, the point of inoculation through 6 cm, showed low pH, measurable oxalic acid, high moisture, and high protein. Zone 2, throug...
C A Clausen
Lignin degradation by a non-enzymatic system supposed to be active in white rot fungi
2000 - IRG/WP 00-10340
Electron microscopic investigations have shown that ligninolytic enzymes of white-rot fungi are only able to penetrate the wood cell wall in late stages of degradation. Thus, the selective degradation of lignin of certain white-rot fungi can only be explained on the basis of a low molecular weight, highly diffusible system. A system, consisting of copper, a coordination compound and either H2O2 or...
P Lamaipis, W Gindl, T Watanabe, K Messner
Hemicellulosic induction of oxalic acid in Postia placenta
1994 - IRG/WP 94-10060
Most studies suggest that enzymes produced by brown-rot fungi are too large to penetrate sound wood structures, even after decay begins. Thus, nonenzymatic agents have been proposed to initiate brown-rot decay. We have reported that the brown-rot fungus Postia placenta MAD-698 initiates a 2-fold decrease in wood pH within 7 days of colonization which is mediated by production of oxalic acid. Strai...
F Green III, M Larsen, T L Highley
The long road to understanding brown-rot decay. A view from the ditch
1995 - IRG/WP 95-10101
Interest in understanding how brown-rot fungi decay wood has received increasing interest in recent years because of a need to identify novel targets that can be inhibited for the next generation of antifungal wood preservatives. Brown-rot fungi are unique in that they can degrade holocellulose (cellulose and hemicellulose) in wood without first removing the lignin. Furthermore, they degrade holoc...
F Green III, T L Highley
Respiration measurement of dry-rot
1995 - IRG/WP 95-10095
Methods for measuring the production of carbondioxide from wood infected with the dry-rot fungus were evaluated. By enclosing whole wood blocks and measuring the concentration of gas in the headspace by gas chromatography, an exponential increase in the concentration of CO2 was observed for at least 2 months. This technique could therefore present a method for evaluating various treatments of dry-...
L Toft
Targeted inhibition of wood decay (Using everything but the kitchen sink)
1997 - IRG/WP 97-10203
Low molecular weight oxidative decay agents have been implicated in the degradation of wood by brown-rot decay as evidenced by chemical analysis of brown-rotted wood and detection of oxalic acid and hydroxy radicals. Fenton chemistry (H2O2 / Fe++) is often proposed as the mechanism for generating hydroxy radicals. Previous authors have shown iron to enhance the brown-rot hydrolysis of wood, while ...
F Green III, T A Kuster, T L Highley
The biological effectiveness of wood modified with heptadecenylsuccinic anhydride against two brown rot fungi: Coniophora puteana and Gloeophyllum trabeum
1992 - IRG/WP 92-3705
A modified soil block test was carried out using wood samples reacted with heptadecenylsuccinic anhydride (ASA). This modification gave good resistance to decay brought about by the brown rot fungi Coniophora puteana and Gloeophyllum trabeum during the twelve week exposure period. Results indicated that there was a good correlation between increased loading of modifying reagent and an increase in ...
C Codd, W B Banks, J A Cornfield, G R Williams
Utilization of coconut timber from north Sulawesi, Indonesia. Part 1: Durability
1994 - IRG/WP 94-30044
Coconut timber from non-productive plantations is a byproduct of an agricultural crop and, by the same token, constitutes a renewable resource which may serve as a complement to or, at least in part, as a substitute for traditional timbers in local markets. Its more extensive utilization is expected to contribute to the conservation of tropical rain forests. Export of coconut timber and/or wood pr...
R-D Peek
Extracellular substance from the white rot basidiomycete Irpex lacteus involved in wood degradation
1992 - IRG/WP 92-1571
Cellulases, phenol oxidase, and a substance that both produced and reduced H2O2 were isolated from cultures containing wood or glucose on which the white-rot fungus Irpex lacteus was growing. The rate of wood degradation by the fungus with different amounts of glucose in the medium was measured. More of the substance that produced and reduced H2O2 was found extracellularly in cultures containing w...
H Tanaka, T Hirano, G Fuse, A Enoki
Lab and field test results for wood treated with polymeric alkylphenol polysulfide
2001 - IRG/WP 01-30268
A new wood preservative based on polymeric alkyphenol polysulfide (PXTS-A) is being evaluated in a series of laboratory and field tests and the results continue to show promise. A modified formulation (PXTS-B), which contains additives to reduce the viscosity, is being evaluated along with the original formulation. Soil block decay tests comparing PXTS-B with CCA-C indicate that PXTS-B is equally ...
J Goswami, A Abramson, R Buff, D D Nicholas, T Schultz
Influence of acidification on decay processes of CCB treated wood
2004 - IRG/WP 04-10514
The phenomenon of copper tolerance by brown rot fungal strains has been known for a long period but the complete mechanism of copper tolerance by these fungi is not understood yet. Copper tolerance has previously been linked to oxalic acid excreted by copper tolerant brown rot fungal strains. This acid reacts with copper in the wood to form an insoluble and therefore less toxic copper oxalate. The...
M Humar, S A Amartey, M Šentjurc, F Pohleven
Durability aspects of (hydro)thermal treated wood
2000 - IRG/WP 00-40160
Samples of several wood species were treated in a two steps process, subsequently hydrothermal and dry heat-treated, by the so-called PLATO-process and analysed for their resistance against fungal attack. Both PLATO-treated and dry heat-treated specimen were prepared and analysed, in order to study the influence of moisture during hydrothermal treatment of wood. The resistance against all of the s...
B F Tjeerdsma, M Stevens, H Militz
Identification of brown rot fungi on wood in above ground conditions by PCR, T-RFLP and sequencing
2004 - IRG/WP 04-10512
Fungi selected in test fields in Germany and Estonia and fungi (Coniophora puteana) cultivated on medium have been identified by the molecular methods PCR (Polymerase Chain Reaction), T-RFLP (Terminal Restricted Fragment Length Polymorphism) and sequenced to species level. The samples from the German field test showed that the fruit body sample was a different fungus than from the mycelium sample....
U Råberg, N Högberg, C J Land
Relative merits of laboratory and field tests for assessing wood decay resistance
1993 - IRG/WP 93-20009
Laboratory and field trials have long been employed for assessing natural durability of a variety of wood species, but there is a continuing debate concerning the relative merits of approach. While laboratory tests provide carefully controlled conditions for decay, they are often criticized for being too artificial to produce meaningful results. Conversely, field trials often vary widely between t...
T C Scheffer, J J Morrell
Preliminary studies of the performance of iron chelators as inhibitors of brown rot (Coniophora puteana) attack
1996 - IRG/WP 96-10185
This paper describes experiments to examine the proposal that the presence of iron is essential for brown rot fungi to utilize hydroxyl radicals remote from the hyphae as a means of converting the wood into a food source. reliminary test results are presented from trials using three different iron chelators impregnated into Scots pine (Pinus sylvestris) sapwood blocks. Their relative effects on th...
E D Suttie, R J Orsler, P M Wood
Cytoplasmic and extracellular localization of manganese II dependent peroxidase(s) in white rot fungi during degradation of woody materials
1989 - IRG/WP 1416
The manner by which lignin is degraded in-situ in natural substrates by white rot fungi still remains a controversial issue particularly the distribution and role(s) played by lignin degrading enzymes (i.e. manganese II peroxidase and lignin peroxidase). In the present study, use was made of anti-manganese II peroxidase and immunolabelling techniques in conjunction with transmission electron micro...
G F Daniel, B Pettersson, T Nilsson, J Volc
Micromorphology of decay in Keruing heartwood by the basidiomycetes Phellinus contiguus and Dacrymyces stillatus
2002 - IRG/WP 02-10454
This study aimed to characterise the micromorphology of fungal decay in a wooden handrailing in an above ground exposure at the Thames embankment in London. Keruing heartwood (Dipterocarpus spp.) was determined as the construction timber and the two basidiomycetes Phellinus contiguus and Dacrymyces stillatus identified as main decay organisms.
Their decay patterns within Keruing heartwood were...
G Kleist, M Ray, R J Murphy