Your search resulted in 1175 documents. Displaying 25 entries per page.
Oxalic acid quantification, oxaloacetase assay and ESI localization of P, C, and Fe from the brown rot fungus Postia placenta
1994 - IRG/WP 94-10063
The mechanism by which brown-rot fungi initiate depolymerization of holocellulose in wood remains unknown. Recently, oxalic acid (OA) has received considerable attention in cellulose breakdown by brown-rot fungi. The OA could serve as a proton donor for hydrolytic or an electron donor for oxidative (Fenton's reaction-H2O2/Fe2+) cleavages of cellulose. The acid may originate via oxaloaceta...
C R Jordan, W V Dashek, T L Highley
Evidence for the participation of the osmiophilic particles in the enzymatic demethylation of lignin
1984 - IRG/WP 1239
Transmission electron microscopic observations of the white-rot fungi Trametes hirsuta and Phanerochaete chrysosporium grown on a series of wood pulp with a graded lignin content and mycelium from the clarified centre of an agar-medium containing lignin (E1-effluent from the bleaching process) showed that osmiophilic particles are only induced by native lignin. Taking into account that the osmioph...
K Messner, H Stachelberger
Proposed model for the penetration and decay of wood by the hyphal sheath of the brown-rot fungus Postia placenta
1989 - IRG/WP 1391
Scanning electron microscopy (SEM) of Pinus sp. decayed by the brown-rot fungus Postia placenta confirmed the existence of extracellular membranous structures previously described by transmission electron microscopy (TEM). These structures appear to be an integral part of the hyphal sheath and assume a variety of forms including lamellar sheets, fibrils, and vesicles. These structures were observe...
F Green III, M J Larsen, L L Murmanis, T L Highley
Production of exraxellular hydrogen peroxide and oxalic acid by brown-rot fungus Poria placenta
1995 - IRG/WP 95-10112
Hydrogen peroxide and oxalic acid have been suggested to be essential in the degradation of wood carbohydrates by brown-rot fungi. Hydrogen peroxide has been suggested to be one of the diffusible low molecular weight agents produced by brown-rot fungi for the degradation of wood carbohydrates by generating highly active radicals. The production of hydrogen peroxide and oxalic acid by Poria placent...
A-C Ritschkoff, M Rättö, J Buchert, L Viikari
Early detection of brown-rot decay in southern yellow pine using immunodiagnostic procedures
1990 - IRG/WP 2356
Immunodiagnostic procedures have been used to detect incipient decay of southern yellow pine by six common brown-rot fungi. Rabbit polyclonal antibodies were raised to liquid culture fractions of the six fungi. The antibodies, after preadsorption to sawdust, were tested in particle agglutination assays, immuno-dot blot, and ELISA for their·ability to detect the decay organisms when they were grow...
C A Clausen, F Green III, T L Highley
A study of the colonization of wood blocks in a laboratory unsterile soil test
1988 - IRG/WP 2318
CCA treated and untreated beech blocks were exposed to a defined horticultural loam using the method proposed for the collaborative soft rot test in the soft rot sub-group of Working Group Two. At intervals during the incubation wood samples were removed and fungal isolations were made using selective media. Fungi were identified and tested for their cellulolytic ability and their decay capacity i...
M T De Troya, S M Gray, D J Dickinson
Degradation of lignin model compounds with coordinated copper in the presence of peroxide
1998 - IRG/WP 98-10282
A novel diffusible system capable of decomposing lignin model compounds with copper, coordinators and peroxides has been proposed. When pyridine was used as a copper coordinator, two synthetic dyes, Poly-R and RBBR were intensively decolorized with Cu(II) and H2O2 in aqueous solutions at room temperature. Although reactions with Cu(II) and H2O2 produce a strong oxidant, hydroxyl radical, via a Fen...
K Koller, K Messner, T Watanabe
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
Enhanced biodegradation of cocopeat by soft rot fungi
1998 - IRG/WP 98-10276
Biodegradation of cocopeat (coir dust) was enhanced by the addition of nitrogen (N) fertilizer and inoculation with the soft rot fungus Chaetomium globosum. The N and fungally treated cocopeats had a greater percentage weight loss (27%) after 3 months compared with 7% weight loss without the added fungi and N fertilizer. In addition, their hemicellulose, cellulose and lignin contents were greatly ...
P Y Yau, R J Murphy
Protection of southern pine using N,N-Napthaloylhydroxylamine: Field tests, soft-rot cellars and aquatic bioassay leach testing
1999 - IRG/WP 99-30204
Recent environmental restrictions are limiting the use of broad-spectrum biocides for wood preservation. There is an urgent need for new, sharply targeted, environmentally benign wood preservatives. N'N-Napthaloylhydroxylamine (NHA), a water-soluble calcium-precipitating agent, has been shown to inhibit decay by brown-rot and white-rot fungi in soil-block tests and prevent damage by Easte...
D M Crawford, F Green III
Soft rot
1978 - IRG/WP 179
Soft rot decay of treated wood is examined with special reference to hardwoods treated with CCA. Factors which adversely affect the chances of protection of hardwoods against soft rot are discussed. The ratio of the volume of the fibre cell wall to the volume of the fibre lumen is presented as a major factor influencing final preservative concentration in the fibre cell wall, the major strength co...
C R Levy
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
Molecular studies on house rot fungi by RAPD-PCR
1997 - IRG/WP 97-10195
For genetic information and in view as a possible diagnosis method various isolates of the dry rot fungus, Serpula lacrymans, the wild merulius, S. himantioides, and the cellar fungus, Coniophora puteana, from Asia, Europe and USA were investigated by the polymerase chain reaction (PCR) based technique of randomly amplified polymorphic DNA (RAPD). The banding patterns obtained revealed for S. lacr...
O Schmidt, U Moreth
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
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
Laboratory testing of wood natural durability - In soil-bed assays
1998 - IRG/WP 98-20141
Laboratory methods for assessing wood decay resistance are being investigated in the framework of an ongoing European research project. This paper summarizes the main results obtained for soil-bed tests based on the European prestandard ENV 807-Test 2. The data suggest that this testing methodology is suitable for evaluating the natural durability of timber species in soil-contact under conditions...
R Sierra-Alvarez, I Le Bayon, J K Carey, I Stephan, J Van Acker, M Grinda, G Kleist, H Militz, R-D Peek
Decay resistance of Platanus acerifolia wood against White Rot Fungi (Coriolus versicolor)
2002 - IRG/WP 02-10431
Degradation of the lignocellulose complex in wood varies on the microorganism causing decay and chemical composition of wood. The weight loss of Platanus acerifolia wood after decay by white rot fungus (Coriolus versicolor) for period 16 weeks were evaluated according to European standard EN 113 and beech wood as a control. The samples were collected in October 2000 from Nantes, France. The aim of...
M Irmouli, O Duchelier, N Ayadi, B Charrier
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
Immuno-electron microscopic localization of extracellular metabolites in spruce wood decayed by brown-rot fungus Postia placenta
1990 - IRG/WP 1441
Degradation by Postia placenta in spruce and birch wood was shown to occur not only in the wood cell wall but also in the middle lamellae region. Middle lamellae was often found to be degraded along the centerline so that cells could separate along this line. Extracellular membrane structures were found surrounding the hyphae and this matrix labelled positively with antisera produced to Postia pla...
Y S Kim, B Goodell, J Jellison
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
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
The effectiveness of three tributyltin compounds in beech against soft rot fungi using a soil-bed technique: A preliminary report
1986 - IRG/WP 3390
The effectiveness, towards soft rot fungi, of bis (tributyltin) oxide, tributyltin ethanesulphonate (TBTES) and benzyltributylammonium tributyldichlorostannate in both leached and unleached beech stakes is compared to that of a CCA preservative (Tanalith CT 106), using a soilbed technique. In addition, the effect of test solvent (water or toluene) on the performance of TBTES is evaluated. Total ti...
R Hill, A H Chapman, B Patel, A Samuel, J K Carey