Your search resulted in 1426 documents. Displaying 25 entries per page.
Preliminary studies of the decay mechanism of some brown-rot fungi
1989 - IRG/WP 1402
The importance of the enzymatic degradation of hemicellulose and cellulose by brown-rot fungi is still under discussion. Endo-ß-1,4-xylanase and endoglucanase activities of Coniophora puteana and Poria placenta cultures were measured by the increase in reducing groups. Enzymes were produced in liquid and solid sawdust based culture media. Enzyme activities were measured in two, four and eight wee...
A-C Ritschkoff, H Viitanen
Decay resistance of Siberian larch wood against brown rot fungi - Part 2. The effect of genetic variation
1998 - IRG/WP 98-10287
Wood natural decay resistance is mainly restricted in the heartwood part of tree and based on wood microstructure and chemical composition. However, the variation of decay resistant in different wood species is vide and the effect of genotype on decay resistance of Siberian larch wood grown in Finland is not known. The aim of this work was to find out the variation on decay resistance of Siberian ...
H Viitanen, L Paajanen, T Nikkanen, P Velling
Soluble nutrient content in wood and its susceptibility to fungal discoloration and decay in above ground and ground tests
2000 - IRG/WP 00-10336
The objective of this comprehensive study was to reveal the impact of soluble nutrients in wood on its susceptibility to fungal discoloration and decay in various tests, which is important for the test methodology and standardisation. Seven tests were carried out including pure culture above and ground contact tests, above ground field test and laboratory ground contact tests. The samples containi...
O M Caballero, N Terziev
Preliminary studies to assess the effects of aeration and lowered humidity on the decay capacity, growth and survival of the dry rot fungus Serpula lacrymans (Wulf ex. Fr.)
1997 - IRG/WP 97-10208
Novel microcosms were used to test separately the effects of aeration and humidity on the decay capacity, linear spread and survival of Serpula lacrymans. The application of a pumped air supply resulted in an effective cessation of fungal activity when all but the lowest of the air flow rates was used. Furthermore, the lowest air flow rate caused marked growth tropisms away from the stress. In sep...
G A Low, J W Palfreyman, N A White, H J Staines, A Bruce
A light and electron microscopic study of decayed CCA-treated radiata pine (Pinus radiata) wood from a cooling tower
1994 - IRG/WP 94-10056
An inspection of an industrial cooling tower in New Zealand showed surface decay of 12 year old Pinus radiata wood panels treated with CCA preservative to a retention of around 15 kg/m³ of salt. Wood decay micromorphology typical of that caused by soft rot fungi, white rot fungi, 'stripy' and 'v-shaped' erosion bacteria and cavitation bacteria were all commonly...
A P Singh, R N Wakeling, D R Page
Generation of hydroxyl radical by the brown-rot fungus, Postia placenta
1988 - IRG/WP 1360
In an electron spin resonance (ESR) survey of various liquid cultures and wood slivers innoculated with the brown-rot fungus, Postia placenta, the spin trap dimethyl-l-pyrroline N-oxide (DMPO) was used to detect the presence of the hydroxyl radical. The ESR spectra for the paramagnetic DMPO- hydroxyl radical adduct was observed in (1) nitrogen-limited, liquid cultures having 1.0% glucose or 0.1% c...
B Illman, D C Meinholtz, T L Highley
Accelerated laboratory testing of preservatives on 13 North American wood species
1999 - IRG/WP 99-30201
The ability of selected water and solvent based biocides to protect wood against fungal attack was evaluated on 13 North American wood species using 7 decay fungi in a modified soil block test. Most preservatives were capable of providing protection at their recommended above ground and soil contact use levels. Many decay fungi caused substantial weight losses on blocks treated with chlorothalonil...
J J Morrell, C M Freitag
Fenton's reagent as a modification tool in brown-rot decay
1996 - IRG/WP 96-10155
A biomimetic approach was used to clarify the role and importance of the Fenton-type reaction in the carbohydrate degradation by brown-rot fungi. Spruce sawdust and microcrystalline cellulose were modified in the H2O2/Fe(II) treatment. The degree of hydrolysis of the pretreated spruce sawdust was clearly increased with the complete cellulase (Econase), purified endoglucanase from Trichoderma reese...
M Rättö, A-C Ritschkoff, J Buchert, L Viikari
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
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
The antifungal efficacy of Guayule resin
1987 - IRG/WP 3429
The Naval Research Laboratory is evaluating the non-rubber-producing portion of guayule (Parthenium argentatum) resin as a protectant for wood in terrestrial and marine service. This study phase, in collaboration with the universities of Arizona and Mississippi State, evaluates the resin's fungicidal worth. Resin-impregnated pine sapwood was exposed to brown rot fungi (Gloeophyllum trabeu...
J D Bultman, R L Gilbertson, T L Amburgey, J E Adaskaveg, S V Parikh, C A Bailey
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
Comparative study of lignocellulolytic activities of Pleurotus spp. and white rot and brown-rot fungi
1997 - IRG/WP 97-10210
In this work, the in vitro species of Pleurotus (P.eringii, P. cornucopiae and P. ostreatus), from structures of degraded wood have been studied. This degradative activity was compared to those presented by Trametes versicolor (fungus characteristic of white rot) and Gloeophyllum trabeum (fungus representative of brown rot). The activities studied were the following: cellulase, xylanase, pectinase...
D Muñoz-Mingarro, F Llinares, M T De Troya, F Rubio, M Yuste, C Rodríguez-Borrajo, J E Garcia de los Rios, F Alvarez, P Jiménez, A Rojas, A Navarrete, P Reche
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
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
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
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
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
Micromorphology of Schizophyllum commune attack in pine (Pinus sylvestris) wood
1983 - IRG/WP 1184
The decay pattern caused by Schizophyllum commune in pine latewood tracheids was studied using both light and transmission electron microscopy. The attack began as isolated concentric slits within the S2 layer with extensive lamellation and separation of individual wall layers observed in subsequent stages of decay. The slits resulting from attack appeared to be formed in thin, regular concentric ...
T Nilsson, G F Daniel
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