Your search resulted in 728 documents. Displaying 25 entries per page.
Questionnaire - Fungal decay types
1985 - IRG/WP 1265
The effect of certain wood extractives on the growth of marine micro-organisms
1977 - IRG/WP 438
S E J Furtado, E B G Jones, J D Bultman
Isolation and identification of the fungal flora in treated wood
1976 - IRG/WP 144
J F Levy
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 an electron donor such as NADH or ascorbic acid and O2 to produce H2O2 via O2·-, and produce ·OH by Fenton's reaction between the ferrous iron bound to the ligands and H2O2. The compounds show no phenol-oxidase activity and catalyze the hydroxylation of phenol to catechol and hydroquinone in the presence of H2O2.
A Enoki, G Fuse, H Tanaka
Field study: Wood degradation pattern in buildings and utility poles in tropical climates of Nigeria
1992 - IRG/WP 92-1521
The paper is the result of five years field study of wood degradation patterns in three ecological forest zones (Guinea Savannah, Tropical rain forest and mangrove forest zones, respectively). It involved 800 residential buildings and 700 electric overhead transmission poles. The methodology used was a modified Eslyn (6) test. A high rate of Ascomycetes and Basidiomycetes attack especially on the windward side of residential buildings was noted. A high incidence of subterranean termite attack as well as their ability to bridge resistant structures to reach their ultimate host was recorded. Powderpost beetles attack in household furniture and fittings made of non-durable wood and sapwood were common, but particle board proved immune. Overhead electric transmission poles pressure treated with cole tar based preservatives proved very resistant to biodeterioration. Seasoning defects are a common feature on the windward side of buildings and a major problem in poles. The author concluded that because of the favourable climate, pressure or other deep penetration treatments is desirable for all non-durable woods in tropical climates. Wood preservative formulations for utility poles should possess some dimensional stabilization properties. Remedial treatments were also recommended for dry rot, termite and powderpost beetles in existing structures.
E O Onuorah
List of fungi observed in avalanche barriers located in subalpine and alpine regions
1970 - IRG/WP 17
In the Subalpine region (Schilt-Stein; 1400-1500 m above sea level) the following fungi were observed: Basidiomycetes: Corticium alutaceum, Corticium ochraceum, Corticium sp., Collybia sp., Dacryomyces deliquescens, Exidia glandulosa, Lenzites abietina, Lenzites sepiaria, Lenzites trabea, Osmoporus odoratus, Peniophora pubera, Peniophora sp., Polystictus abietina, Poria placenta, Poria mucida, Poria versipora, Poria sp., Schizophyllum commune, Stereum sanguinolentum. In the Alpine region (Dorfberg-Davos; 1900-2500 m above sea level) the following fungi were observed: Basidiomycetes: Corticium alutaceum, Corticium ochraceum, Cyphella sp., Dacryomyces deliquescens, Exidia glandulosa, Flammula sp., Hydnum alutaceum, Hymenochaeta fuliginosa, Hypholoma sublateritium, Lenzites abietina, Lenzites sepiaria, Mycena sanguinolenta, Nematoloma fasciculare, Osmoporus odoratus, Peniophora gigantea, Peniophora pubera, Peniophora subtilis, Peniophora sp., Phellinus nigrolimitatus, Polyporus adustus, Polyporus fragilis, Polystictus abietina, Poria medulla panis, Poria placenta, Poria reticulata, Poria taxicola, Poria vaillantii, Poria vaporaria, Poria versipora, Schizophyllum commune, Stereum sanguinolentum, Trametes pubescens, Trametes serialis Ascomycetes: Geoglossum sp., Lachnea scutellata, Otidea sp. Myxomycetes: Acryria punicea, Stemonitis fusca.
Isolation and identification of the fungal flora in treated wood. Revised technique
1977 - IRG/WP 159
At the 8th Annual Meeting in Wildhaus a paper was presented for discussion on the isolation of fungi from treated wood.·Since then work of this nature has been undertaken at Imperial College and as a result a revision of that document has been made and is presented here. The main alterations are: 1) To streamline the isolation procedure 2) Modification of the benomyl agar 3) The inclusion of a standard, low concentration malt medium, for the comparison of all isolates. This was found to be necessary due to the similar appearance of the same organism on different mediar. This isolation procedure thus supersedes the previous one outlined in Document No: IRG/WP/144.
C P Clubbe, J F Levy
Dynamics of fungi colonization on the surface of Scots pine wood during natural weathering in different European climate zones
2022 - IRG/WP 22-10984
Wood The presence of fungi leads to biomaterial decay and/or changes in aesthetical appeal. The start of fungi colonization as well as the following growth on wood are primarily influenced by four factors: ambient temperature, moisture history of the object, access to oxygen, and intrinsic properties of the exposed wood, considered here as a source of nutrients for microorganisms. A prevalence of fungal spores in a close vicinity, combined with favourable environmental conditions are indispensable for the initiation of the growth of microorganisms. All the above factors are highly dependent on the local circumstances and especially climate conditions. It is important to understand the effect of weather on the diversity and distribution of endemic fungal communities in advance, to identify plausible remedies as related to the present global climatic changes. It is foreseen that the composition of fungal cultures as well as their growth kinetics on various wood substrates may evolve in the near future. The goal of this study was to investigate the relationship between specific weather conditions, representing diverse climate zones, on the occupancies and colonization dynamics of fungi/mould species. The test was performed on untreated Scots pine (Pinus sylvestris L.) wood samples exposed to natural weathering for 12 weeks from July to September 2021, in two locations: 1) Izola (Slovenia, 45°32'12.98"N, 13°39'42.98"E), representing the mild Mediterranean climate of southern Europe, and 2) Skellefteå (Sweden, 64°45'2.41"N, 20°57'10.04"E) representing Scandinavian or northern Europe climate zone. The local weather conditions recorded during the exposure period were used for modelling the growth kinetics. Fungi colonizing wood surfaces were manually collected from twin samples at each location, every second week, by swabs and cultured on nutrient media. The identification of fungi was performed visually according to the mycological keys of the detected genus. The presence of fungi was first noticed after 2 weeks of exposure. The majority of species detected were Ascomycetes from the genus Cladosporium, Aureobasidium, and Aspergillus. The combination of climatic parameters influences the compositions and colonisation of microorganisms on Scots pine wood. However, the obtained results showed fluctuations in the colonisation of the spores of culturable fungi. This might be the influence of other factors including geographic location, sensitivity of each fungal species to environmental factors, animals, plants, human activities, and pollutants that need to be taken in account.
F Poohphajai, O Myronycheva, O Karlsson, L Rautkari, J Sandak, A Sandak
Which fungi cause sapstain in Canadian softwoods?
1998 - IRG/WP 98-10285
The Canadian forest products industry suffers considerable losses in revenue due to fungal stains. There is an increased awareness that more complete knowledge about the causal organisms might help solve the problem. A first step was to initiate a thorough survey of bluestain fungi in Canada. Systematic sampling was done at seven selected sawmills in six Canadian provinces. In summer 1997 fresh logs and lumber were set aside a month prior to sampling for fungi. Five commercially important softwoods, Abies balsamea, Picea mariana, P. glauca, Pinus contorta and P. banksiana were included in the studies. The objectives were to identify the main discoloring fungi and subsequently to evaluate the genetic diversity among isolates of the fungal species found to predominate. Fungi isolated from the experimental timber were identified based on their morphological characteristics, measurement of their growth rates, and by testing their mating compatibility with known mating types. A substantial number of isolates and a variety of species were obtained. Most frequently isolated were species from the genus Ophiostoma. A more diverse range of fungi was found in logs than on lumber. Preliminary data suggest that some species tend to predominate on certain wood species and in certain geographic regions but none appeared to be exclusive.
A Uzunovic, Dian-Qing Yang, P Gagné, C Breuil, L Bernier, A Byrne
Effect of acetylation on decay resistance of wood against brown-rot, white-rot and soft-rot fungi
1989 - IRG/WP 3540
Effect of acetylation on decay resistance of wood was investigated using wood blocks of Cryptomeria japonica, Pinus densiflora, Albizia falcata and Fagus crenata. Blocks were treated with uncatalyzed acetic anhydride for different lengths of time and exposed to Tyromyces palustris, Serpula lacrymans, Coriolus versicolor and unsterilized soil. The action of OH-radical on acetylated wood was also examined using Fenton's reagent. The enhancement of decay resistance by acetylation was revealed clearly for all cases of exposures but varying with fungal and wood species used. For a brown-rot fungus Tyromyces palustris, the weight loss reached almost nil in all woods at 20 WPG (weight percent gain) of acetylation, after the striking decrease from 10 to 15 WPG. For a white-rot fungus Coriolus versicolor, it was counted until 12-15 WPG in the perishable hardwoods used, but not in a softwood Cryptomeria japonica, even at 6 WPG. In cases of another brown-rotter Serpula lacrymans and soil burial, effect of acetylation was intermediate between Tyromyces palustris and Coriolus versicolor. Anti-degradation mechanism by acetylation was discussed, from these weight loss - weight gain relationships, and the IR-and 13C-NMR spectral analyses of fungus-exposed wood.
M Takahashi, Y Imamura, M Tanahashi
JWPA method for testing effectiveness of surface coatings with preservatives against decay fungi
1981 - IRG/WP 2164
In 1979 JWPA established a new method for testing effectiveness of surface coatings in accordance with practical use of preservative-treated lumber. Comparing the new testing method with JIS A 9302, a few new trials - size of wood specimen, weathering procedure, and decay-test procedure - are incorporated.
Preliminary study of the fungicidal and structural variability in copper naphthenates and naphthenic acids
1996 - IRG/WP 96-30114
Copper naphthenates, an oil-borne wood preservative listed by the American Wood-Preservers' Association (AWPA), is manufactured by complexing copper(II) with naphthenic acids. Prior to AWPA listing as a wood preservative, field experiments showed that copper naphthenates generally had good stability and were active against wood-destroying organisms. Recently, however, there have been reports of some copper naphthenate-treated poles rapidly failing. One possible explanation for the varying effectiveness could be that the structure, and resulting biological activity, of the naphthenic acids used to make copper naphthenate may vary. To test this hypothesis several naphthenic acids and copper naphenates were obtained and their fungicidal activity against three wood-destroying fungi measured. In addition, the chemical structure of the naphthenic acids were examined by proton- and carbon- NMR. Different activities were observed, especially against a copper-tolerant fungus. Some apparent correlations were seen between the fungicidal activity and chemical structures for the few samples studied.
T Schultz, D D Nicholas, L L Ingram Jr, T H Fisher
Inhibition of wood-inhabiting fungi by actinomycetes
1981 - IRG/WP 1137
Actinomycetes of the genera Streptomyces, Micromonospora, Microtetraspora, Nocardia and Rhodococcus, isolated from wood, were laboratory tested for their inhibitory effects against the Basidiomycete fungi Polystictus sanguineus and Sistrotrema brinkmannii. One-third of the representatives of the genus Streptomyces which were tested produced significant inhibitory zones whereas actinomycetes belonging to the other genera did not.
M S Cavalcante, R A Eaton
Nondestructive Evaluation of Oriented Strand Board Exposed to Decay Fungi
2002 - IRG/WP 02-20243
Stress wave nondestructive evaluation (NDE) technologies are being used in our laboratory to evaluate the performance properties of engineered wood. These techniques have proven useful in the inspection of timber structures to locate internal voids and decayed or deteriorated areas in large timbers. But no information exists concerning NDE and important properties of wood composites exposed to decay fungi. For our pilot study on several types of wood composites, we examined the relationship between nondestructive stress wave transmission, decay rate and the bending properties of OSB exposed to the brown-rot fungus, Gloeophyllum trabeum (MAD-617). The following measurements were taken: stress wave transmission time (pulse echo test method), static bending test (ASTM D3043-95), and decay (expressed as percent weight). Stress wave measurements correlated with strength loss and with increasing rate of fungal decay. Stress wave NDE has great potential as a method for inspection of wood composite load-bearing (in-service) structures, detection of decay in laboratory tests, assessment of chemical additives to improve wood composite durability, and prediction of long term composite performance.
B Illman, V W Yang, R J Ross, W J Nelson
Screening potential preservatives against stain and mould fungi on pine timber in Zimbabwe
1995 - IRG/WP 95-30063
The search for environmentally and toxicologically safer chemicals for use in the timber preservative industry against stain and mould fungi has been intensified during the past few years. Results of field tests with two chemicals previously evaluated in the laboratory are presented. The conventional sodium pentachlorophenate was the more efficacious chemical against stain and mould fungi, providing up 90% control at a concentration of 2.5%. A potential alternative, Stopstain a borate-based chemical, gave results only slightly better than the untreated control timber, at a concentration of 5%. Unless the environmental cost and toxicological hazards of traditional chemicals are highlighted the newer and safer chemicals will be reluctantly accepted by industry as they are regarded as being prohibitively expensive.
A J Masuka
Moisture content levels and decay of hemlock
1986 - IRG/WP 1287
As a model of decay conditions of wooden members in wooden houses, a decay test was set up in which samples of western hemlock (Tsuga heterophylla) under 4 moisture levels were examined. Each week the samples were weighed and if the weights indicated that their moisture contents were lower than the expected levels, distilled water was added. Every 8 weeks 3 samples from each condition were oven dried at 60°C for 48 hours, up to 48 weeks. After 48 weeks, 3 samples from each condition were oven dried every 16 weeks. The results obtained were as follows: After examining the samples for 96 weeks at 27°C, the mean weight loss of the hemlock samples kept at about 50-100% moisture content level was larger than those of the other levels. If the samples were dried every 8 weeks, the amount of decay in them was not significant. Decay was also not significant in the samples kept at approximately 20-30% moisture content level.
The restricted distribution of Serpula lacrymans in Australian buildings
1989 - IRG/WP 1382
Temperature data has been gathered over a number of years, not only for flooring regions of various buildings in Melbourne, but also within roof spaces and external to the buildings. Findings are discussed in relation to the distribution of Serpula lacrymans within Australia, its restriction to certain types of building construction and its restriction to flooring regions. The subfloor spaces of badly-ventilated, masonry buildings are highlighted as being better suited than are the subfloor spaces of, for example, Japanese buildings for the activity of this fungus. Hence Serpula lacrymans is very restricted in its distribution in Australia, yet where it is active it does grow rapidly and causes rapid flooring failures.
J D Thornton
Monographic cards for wood-destroying fungi. [Fiches monographiques pour les champignons lignivores]
1970 - IRG/WP I 5B
On Donkioporia expansa (Desm.) Kotl. & Pouzar
1986 - IRG/WP 1285
Donkioporia expansa is found more often in houses than realised until now. Virulence tests according to EN 113 show not only an attack of oak, but also of other hardwoods and even soft-woods.
Additions and corrections to recent names for some common decay fungi
1977 - IRG/WP 167
Effect of medium-term degradation of beech wood by erosive (Phanerochaete chrysosporium) and lignin-selective (Ceriporiopsis subvermispora) strains of white rot fungi on its selected physical properties
2004 - IRG/WP 04-40292
At the Faculty of Wood Sciences and Technology a fungal delignification of normal and tension beech wood by erosive and lignin-selective strains white-rot fungi has been studied. The pre-treatment of both kind of wood samples was accompanied by partial delignification and apparent changes of their physical properties influencing the polar liquids penetration.
R Solár, S Kurjatko, M Mamonová, J Hudec
Essais biologiques sur poteaux traités à la Wolmanit C.B. suivant le procédé Boucherie modifé
1974 - IRG/WP 336
D Lapetite, C Jacquiot, J Campredon
Blue stain in service on wood surface coatings. Part 3: The nutritional capability of Aureobasidium pullulans compared to other fungi commonly isolated from wood surface coatings
1993 - IRG/WP 93-10035
The nutritional capability of Aureobasidium pullulans was previously examined, using agar plate tests, with regard to nutrient sources that are potentially available in fresh and weathered wood (Sharpe and Dickinson, 1992). This study compared these findings with the nutritional capability of four other fungi (Alternaria sp., Cladosporium cladosporoides, Stemphylium sp. and Trichoderma sp.) commonly isolated from wood surfaee coatings. The liquid culture techniques were used to assess the relative abilities of the fungi to utilise a range of simple sugars, wood sugar alcohols, hemicelluloses, cellulose and lignin degradation compounds. The observations were used to explain why Aureobasidium pullulans is able to occupy so successfully, often in monoculture, the wood-paint interface niche.
P R Sharpe, D J Dickinson
Effects of acetylation on the dimensional stability and decay resistance of kenaf (Hibiscus cannabinus L.) fiberboard
1996 - IRG/WP 96-40059
The objective of this study was to investigate the influence of the acetylation treated kenaf fiber, Phenol formaldehyde resin content level, and three fungi species on the dimensional stability and decay resistance of high density non wood composition boards. A standard ASTM method was used to evaluate weight loss and thickness change. The linear shrinkage and expansion of each species were also determined. All specimens were exposed to decay chambers for 16 weeks. Test results indicated that most of the main factors significantly influence the thickness, length changes, and decay resistance of the high density kenaf fiberboards.
P Chow, T Harp, R Meimban, J A Youngquist, R M Rowell