Your search resulted in 32 documents. Displaying 25 entries per page.
Decay resistance of wood removed from poles treated with Trichoderma
1989 - IRG/WP 1386
Wood blocks removed from a distribution pole previously treated with a biological control product (Binab FYT pellets) were exposed in soil block tests to selected basidiomycetes. The blocks were removed from regions of poles where Trichoderma colonization had been confirmed by extensive sampling and computer mapping of microbial inhabitants. The results indicate that material from pole interiors colonized by Trichoderma is able to resist decay by Lentinus lepideus and Antrodia carbonica. Any decay prevention was lost however when the wood was steam sterilized prior to exposure to the basidiomycetes. The implications of the results for the use of biological control of internal decay in creosoted poles is briefly discussed.
A Bruce, B King, T L Highley
Evaluation of bacteria for biological control of wood decay
1990 - IRG/WP 1426
Laboratory soil-block and agar-block tests were carried out to evaluate the efficacy of bacteria as biological control agents against 5 brown-rot and 3 white-rot fungi. Pretreatment of Southern pine and sweetgum with a bacterial solution prevented decay in agar-block tests. However, the bacteria were generally ineffective in preventing decay in Southern pine, Douglas-fir, sweetgum and yellow poplar in soil-block tests. Wood blocks treated with an autoclaved bacterial solution were not decay resistant by either test method.
R Benko, T L Highley
The dry rot fungus and other fungi in houses. Part 2
1993 - IRG/WP 93-10001
An attempt to evaluate wood resistance against fungal decay in non-sterile conditions by measuring the variation of resistance to bending test
1988 - IRG/WP 2308
The main object of this work was to determine the variation of strength on large test specimens of wood (800 x 45 x 45 mm³) when exposed to accelerated fungal attacks close to natural conditions, out of test vessels. The modulus of elasticity (MOE) and the modulus of rupture (MOR) have been assessed. Thereby, the natural resistance of the wood species to fungal decay, the efficiency of preservative as well as the treatment applied are discussed. The wood tested is a guianese secondary species (Couma guianensis). The fungi tested are two guianese strains of brown and white rot. The exposure time is 12 weeks. No mould contamination has been recorded by use of a selective fungicide. The results obtained show that it is possible to infest in nonsterile conditions large wood specimens. Furthermore, modulus of rupture appears to be the most reliable criterion. The investigation, that requires limited equipment and staff could be performed in any tropical research station as it has been done at CTFT, French Guiana center.
L N Trong
The dry rot fungus and other fungi in houses. Part 1
1992 - IRG/WP 92-2389
Monographic card on Antrodia serialis
1984 - IRG/WP 1145
Effect of asphyxiation on wood decay fungi treated
with argon and nitrogen gas
2002 - IRG/WP 02-10452
The effects of low-oxygen conditions, achieved with either argon or nitrogen gas, on the viability of wood decay fungi Coniophora puteana, Antrodia vaillantii and Trametes versicolor, cultivated on PDA medium and infected wood samples, were examined. The fungal cultures were exposed to low oxygen concentration (below 10 ppm) for one to five weeks in hermetically sealed vessels. Anoxic treatment did not affect T. versicolor cultures in the time span of the experiment. Therefore treatment of only C. puteana and A. vaillantii mycelial cultures was extended to 10 and 16 weeks. After treatment, respiration and regeneration of mycelium were tested by measurements of CO2 production and resumed growth of hyphae onto fresh PDA growth medium. The effect of anoxic conditions on the mycelia of treated fungal species was expressed as an increased time needed for regeneration or as a complete absence of growth of inocula taken from the exposed cultures or wooden blocks reintroduced on new nutrient medium. The cultures that were retarded by the low oxygen concentration consequently produced less CO2. For C. puteana cultures, the effects of anoxic treatment became evident in the second week of the treatment. The number of affected cultures rose steadily with the prolongation of anoxic treatment. By the sixteenth week of the anoxic treatment, 80% of the inocula of C. puteana did not regenerate. A. vaillantii inocula regeneration was not affected until after the fourth week of treatment, and similarly for infected wood samples, after five weeks. The influence of anoxic treatment on the cultures of this species was more pronounced on the tenth and especially after the sixteenth week, when 67% of inocula did not regenerate. In general fungal species were differently sensitive to asphyxiation. T. versicolor cultures were not affected by anoxic conditions, caused by either argon or nitrogen gas, and A. vaillantii mycelial cultures proved to be less sensitive than those of C. puteana. In the test with infested wood blocks argon proved to be more effective, compared to nitrogen gas.
C Tavzes, F Pohleven, M Janisek, R J Koestler
About the relations between the natural durability of some tropical species and their extractives content
1983 - IRG/WP 1208
G R Y Déon
Experience with an industrial scale-up for the biological purification of CCA-treated wood waste
1997 - IRG/WP 97-50095
The biological purification of CCA-treated wood waste was tested in co-operation of the BFH and the Italian impregnation plant SoFoMe. Chipped poles were infested with the chromium and arsenic tolerant brown-rot fungus Antrodia vaillantii which can transform in the laboratory ca. 90% of the chromium and arsenic into watersoluble salts. These can be leached to 100-200 ppm residual metal content. The fermentation techniques tested will be described and the fermentation success as well as the possible use of the purified material will be discussed.
H Leithoff, R-D Peek
Bioprocessing preservative-treated waste wood
2000 - IRG/WP 00-50145
Disposal of preservative-treated waste wood is a growing problem worldwide. Bioprocessing the treated wood offers one approach to waste management under certain conditions. One goal is to use wood decay fungi to reduce the volume of waste with an easily managed system in a cost-effective manner. Wood decay fungi were obtained from culture collections in the Mycology Center and Biodeterioration research unit at the USDA-FS Forest Products Laboratory (FPL), Madison, Wisconsin, and from FPL field sites. The 95 isolates had originally been taken from at least 66 sites from around the United States. Isolates were screened in a bioassay (known as the 'choice test') for tolerance to CCA, ACQ, creosote and pentachlorophenol. A tolerant rating was based on fungal growth toward or on treated wood, with 17 tolerant to CCA, 21 to ACQ, 12 to creosote and 5 to pentachlorophenol. Decay capacity of the tolerant isolates was determined as percent weight loss by the ASTM D-1413-76 soil bottle method. We identified 8 isolates for experiments on preservative remediation. Isolates of Meruliporia incrassata and Antrodia radiculosa gave the highest percent degradation of ACQ and CCA-treated wood. Several A. radiculosa isolates and a Neolentinus lepideus isolate grew on creosote-treated wood, but had only a 4-5% weight loss. In this paper we discuss the potential use of decay fungi to degrade or remediate preservative-treated wood.
B Illman, V W Yang, L Ferge
Determination of absorption, accumulation and transport of copper in mycelium of some wood decay fungi
1999 - IRG/WP 99-10323
Copper compounds are common wood preservatives. However, tolerance of some wood decay fungi to copper compounds has been observed recently. Therefore, we tried to elucidate possible causes of this phenomenon. We investigated uptake, accumulation and secretion of copper in the mycelium of potentially copper tolerant fungi (Antrodia sp.) and non tolerant fungus Trametes versicolor. We observed that potentially tolerant fungi have lower uptake of copper to the mycelium than non tolerant species. They also do not transport copper into the medium. That means that copper tolerance of fungi is probably based on low uptake of copper to the mycelium and not on the active transport from the mycelium to the medium.
F Pohleven, S Breznikar, P Kalan, M Petric
Microbial decomposition of salt treated wood
1993 - IRG/WP 93-50001-22
Specialized microorganisms which are able to convert fixed inorganic preservatives from treated wood into water soluble components are investigated. A number of brown rot fungi like Antrodia vaillantii have been isolated from cases of damage and examined under unsterile conditions with CCA-, CCB-, CCF- and CC-treated wood at retention levels of at least 50% higher than recommended for wood in ground contact. Depending on the kind of fungus, preservative retention, wood particle size, culture conditions and duration Cr and As can be almost completely leached from the treated wood. Cu reacts with oxalic acid to a compound of limited water solubility.
R-D Peek, I Stephan, H Leithoff
Feasibility of using biological control agents to arrest and prevent colonization of Douglas fir and southern pine by decay fungi
1988 - IRG/WP 1345
The use of microfungi to control basidiomycetous decay has been evaluated in Europe for many years, where it has produced mixed results against Lentinus lepideus Fries, the fungus presumed to be the major cause of decay in Scots Pine poles. In the United States, remedial decay control has been largely chemical, with little use of alternative decay control strategies. Increasing restrictions on chemical usage have stimulated renewed interest in biological decay control. In our tests, a European biological control, BinabÒ,was evaluated for its ability to prevent or arrest attack of southern pine sapwood or Douglas fir heartwood by 5 Basidiomycetes commonly isolated from poles in service. Lentinus lepideus was included as a comparison. In general, BinabÒ performed well against Lentinus lepideus and the other brown rotters, but was unable to completely eliminate most of the test fungi. In addition, the biological had little effect on white rot fungi, which are an important component of the microflora in decaying poles. The results suggest that biologicals will not be suitable for remedial decay control without supplemental treatments that favor growth and activity of the biocontrol agent.
J J Morrell, C M Sexton
Decay in window joinery in Sweden
1977 - IRG/WP 390
Systematic investigations of decay in window joinery in Sweden have not been undertaken until very recently. One might guess that one of the reasons for the minor interest is that this type of joinery did not rot strikingly faster than people expected. In the last 10-15 years, however, house owners, tenantowners, building societies and others have repeatedly argued that windows do rot more than in earlier days. As long as reliable figures supporting these complaints were not presented, only little attention was shown by the house-building industry and the authorities responsible for the building sector. Finally, 1974, Sveriges Allmännyttiga Bostadföretag (SABO), one of the major public building societies in Sweden, with financial support from the Building Research Council, started a special investigation of their dwellings with regard to rotting window joinery. When the results of this investigation was presented in September 1975, the magnitude of the problem became apparent and further investigations were immediately started.
Intraspecific variability of durability of Wapa courbaril (Eperua grandiflora) against Antrodia sp. and Coriolus versicolor: effect of radial and height position in the stem
2004 - IRG/WP 04-10531
The variation of a lesser-used species, Eperua grandiflora attacked by brown and white rot has been examined. Trees of this specie showed differences in their behaviour against the type of rot used and also showed evidence of intra and inter tree variation. The “tree” effect is very significant concerning natural resistance. In the same way, there is variation of durability observed according to radial and vertical position in the stem. Although the vertical effect is less significant from practises point of view.
N Amusant, J Beauchêne, M Fournier
Growth of the copper tolerant brown rot fungus Antrodia vaillantii on different substrates
1995 - IRG/WP 95-10121
In recent years the copper tolerant brown rot fungus Antrodia vaillantii caused severe damages on impregnated wood in ground contact. The pattern of decay gave the impression that impregnated wood was even more severely attacked than unimpregnated. To investigate this question more closely laboratory tests were carried out. In a "choice test" Antrodia vaillantii grew preferably towards CC-impregnated wood. Furthermore, when adding nutrients to the specimens, the mass loss of impregnated wood significantly increased, while the nutrients did not affect the mass loss of the unimpregnated wood. In addition, the temperature tolerance of the fungi increased slightly when growing on impregnated wood. It could also be shown that Antrodia vaillantii reacts with an increased production of oxalic acid to the presence of a CC preservative.
H Leithoff, I Stephan, M-T Lenz, R-D Peek
Characterization of Poria indoor brown-rot fungi
1995 - IRG/WP 95-10094
The heterogeneous group of "Poria" fungi causing brown rot in buildings and also of wood in ground contact comprises Antrodia vaillantii, Antrodia serialis, Antrodia sinuosa, Antrodia xantha and Tyromyces placenta. These fungi have similar morphological appearance and biology. Their nomenclature has a confusing history and is still not uniform. As a consequence, misinterpretations may occur. SDS polyacrylamide gel electrophoresis showed a species-specific protein pattern for different cultures of Antrodia vaillantii separating the species from the other pore fungi as well as from Coniophora puteana and Serpula lacrymans. Electrophoresis also detected misidentifications. Investigations on growth rate, response to temperature, copper tolerance and wood decay revealed: Radial growth extension reached from 4 to 9 mm/d. Temperature optimum was 25 to 31°C. All withstood 1 hour at 60°C and some even 3 h at 65°C. Antrodia vaillantii was copper tolerant up to 0.05 M Cu. Wood weight loss after 20 weeks was higher by Tyromyces placenta (35%) and Antrodia sinuosa (33%) than by Antrodia xantha (21%), Antrodia serialis (16%) and Antrodia vaillantii (14%). Dual cultures revealed various inter- and intraspecific interactions and detected identity of differently coded cultures of a species. The former Poria vaporaria sensu Liese 'Normstamm II' for testing wood preservatives and the recent Poria placenta EN 113 strain FPRL 280 were shown to be either identical or at least sister monokaryons originating from the same individual.
Effects of air-seasoning on fungal colonization and wood strength of Douglas fir poles
1987 - IRG/WP 1315
Air seasoning economically reduces the moisture content of Douglas fir poles before pressure treatment with preservatives. Advanced decay in poles in service has resulted when decay fungi (Basidiomycetes) colonized poles during air-seasoning and survived the treatment process. These problems have led to recommendations to severely limit this practice. To determine the role of these fungi in peeled and unpeeled Douglas fir poles during air-seasoning in the Pacific Northwest, we identified many of the fungi involved, measured their effect on wood strength, and studied methods for limiting fungal colonization. Over 90 percent of peeled poles air-dried for more than 1 year contained decay fungi, suggesting that air-seasoning in the Pacific Northwest might pose some hazard; however, no significant strength losses were noted in poles dried 1 to 2 years. Poles seasoned for 3 years began to show significant strength losses, but these strength values fell within suggested design parameters for Douglas fir poles. Although Douglas fir poles are colonized by decay fungi as they dry, our results indicate that these fungi do not cause serious damage for at least 2 years. On the basic of these results, we recommend that poles be air dried no longer than 3 years in the Pacific Northwest. We also emphasize the importance of heating air-seasoned wood adequately during the treatment process to kill any fungi present.
J J Morrell, M E Corden, R D Graham, B L Kropp, P Przybylowicz, S M Smith, C A Sexton
rDNA-ITS sequence of Serpula lacrymans and other important indoor rot fungi and taxon-specific priming PCR for their detection
1999 - IRG/WP 99-10298
Taxon-specific priming polymerase chain reaction (TSPP) is a powerful molecular tool for fungal diagnosis. For its application to indoor rot fungi, the internal transcribed spacer (ITS) of the ribosomal DNA (rDNA) of the main fungal species causing wood rot in European buildings was amplified with the polymerase chain reaction (PCR). The ITS region was sequenced. The complete sequences are presented. From base sequence divergency among the fungi, species-specific oligonucleotide primers were designed for TSPP. These marker molecules were suitable for the differential diagnosis of the dry rot fungus, Serpula lacrymans, the wild merulius, S. himantioides, the oak polypore, Donkioporia expansa, the brown cellar fungus, Coniophora puteana, the broad-spored white polypore, Antrodia vaillantii, the sap polypore, Tyromyces placenta, and the yellow-red gill polypore, Gloeophyllum sepiarium. Each specific marker identified isolates of its respective target species. Cross reaction with 'foreign' fungi was the exception. Species identification from unknown field samples from rot damage in buildings is also possible, because DNA from contaminating organisms does not response to the specific primers. Our variant of the technique is fast, because no preceding fungal pure cultures, no special DNA extraction/purification, and no restriction by endonucleases are necessary.
O Schmidt, U Moreth
Changes of EPR spectra of wood, impregnated with copper based preservatives, during exposure to Antrodia vaillantii
2000 - IRG/WP 00-10355
Spruce wood (Picea abies) samples were impregnated with two different aqueous solutions: copper(II) octanoate with ethanolamine or copper(II) sulfate (cCu = 1,0 x 10-2 mol/l). Impregnated and unimpregnated test pieces were exposed to wood rotting fungus Antrodia vaillantii. Some strains of this fungus are known as copper tolerant. After four weeks of exposure to A. vaillantii, we could not detect any Electron Paramagnetic Resonance (EPR) signal of Cu(II) in the spectrum of copper(II) sulfate treated wood. This means that Cu(II) was translocated or conversed into a form that cannot be detected by EPR. Instead of copper signal, manganese signal appeared. The same, manganese signal appeared also in untreated wood, after exposure to A. vaillantii. On the other hand, line shapes of the EPR spectra of Cu(II) in copper(II) octanoate/ethanolamine treated wood changed by rotting, from anisotropic to isotropic. We believe that these changes are mostly caused by oxalic acid, excreted by A. vaillantii, because we observed the same changes on EPR spectra of impregnated and unimpregnated wood, additionally treated with oxalic acid.
M Humar, M Petric, F Pohleven, M Šentjurc
Copper tolerance of various Antrodia vaillantii isolates
2001 - IRG/WP 01-10406
Copper based preservatives have been extensively used in the field of wood preservation. However, several brown-rot fungi to be tolerant to copper and consequently, efficacy of copper based wood preservatives may not be sufficient. Copper tolerance is especially by some fungi that are closely aligned to or included in genus Antrodia. The highest copper tolerance was found at some strains of wood rotting fungus A. vaillantii. In this research, we investigated the variation of tolerance to copper among 14 isolates of Antrodia using different screening tests. Screening test on potato dextrose agar wasused as nutrient medium. The concentration of copper(II) sulfate in growth medium varied between 1.0x10-3 mol/l and 5.0x10-2 mol/l. There was almost no growth detected at all observed isolates when nutrient media contained the highest concentration of copper. Nevertheless, six strains were still able to grow on solid media containing 2.5x10-2 mol/l of copper. Further tests confirmed copper tolerance atselected isolates. Thus we can conclude that various isolates performed different copper tolerance.
F Pohleven, A Malnaric, M Humar, C Tavzes
Selecting fumigants for treatment of internal decay in wood
1986 - IRG/WP 3370
A number of potential fumigants were screened with respect to their toxicity to decay fungi, (Poria carbonica, and Lentinus lepideus) and their sorption characteristics on Douglas Fir (Pseudotsuga menziesii Mirb. Franco) wood. Wafers of infected wood were exposed to different fumigant concentrations for various times then cultured to determine viability. The lethal concentration X time (ct) factors were determined for each fungus species and fumigant chemical. The "pulse chromatograph technique" was used to determine sorption isotherms for the fumigants to establish the relative degree of interaction between the chemicals and wood. Formaldehyde, chloropicrin (trichloronitromethane), and methylisothiocyanate (MIT) were the most fungitoxic of the chemicals investigated. MIT had the strongest affinity for wood, suggesting that this fumigant should persist longer in treated wood than chloropicrin. The proportion of vapor adsorbed on wood increased greatly with decreasing temperature and was generally higher in decayed wood than in sound wood and in 8% moisture content wood than in dry wood.
P A Cooper
Antagonism of Scytalidium lignicola against wood decay fungi
1989 - IRG/WP 1392
Antagonistic abilities of Scytalidium lignicola against white- and brown-rot wood decay fungi were evaluated. Scytalidium lignicola did not produce inhibition zones but overgrew the decay fungi on a malt-agar medium and in most cases killed them. Pretreatment of Douglas-fir and Southern pine blocks with Scytalidium lignicola prevented decay. Blocks that were heated or treated with propylene oxide to kill the antagonist were not decay resistant. Thus, Scytalidium lignicola does not confer a residual fungistatic effect to wood. Scytalidium lignicola was able to eradicate all the decay fungi in wood except for Postia placenta and Gloeophyllum trabeum. Wood blocks treated with filter-sterilized filtrates of Scytalidium lignicola were not decay resistant, and filtrates were not inhibitory to growth of the decay fungi in agar medium. The antagonistic effect, therefore, apparently does not involve toxins.
T L Highley
Fungal degradation of wood treated with metal-based preservatives. Part 1: Fungal tolerance
1996 - IRG/WP 96-10163
In recent years, concerns have arisen about the leaching of heavy metals from wood treated with chromated copper arsenate (CCA), particularly because of the large amount of CCA treated wood that will be discarded in the coming years. The long term objectives of this work are to determine the fate of copper, chromium and arsenic with the aging and potential decay of CCA-treated wood, and to develop strategies for recycling and remediation of disposed wood. In this study, we determined the ability of various decay fungi to decompose southern yellow pine wood treated with CCA or other metal-based preservatives. Isolates of Meruliporia incrassata and an isolate of Antrodia radiculosa caused the highest weight losses in CCA-treated southern yellow pine. One isolate of Meruliporia incrassata produced similar weight losses in CCA-treated and untreated southern pine after 10 weeks. Pine samples treated with very high levels of copper sulphate were decayed by Meruliporia incrassata, but the fungus was unable to decay wood treated with copper napthenate or copper-8-quinolinolate.
B Illman, T L Highley
Correlation between modulus of elasticity, mass losses and FTIR spectra of copper treated decayed wood
2006 - IRG/WP 06-10580
The composition of copper-based preservatives will change from copper-chromium to copper-ethanolamine, due to environmental demands. The most important drawback of copper-impregnated wood is the presence of tolerant fungal organisms that have developed an ability to degrade such preserved wood. In order to elucidate these processes, specimens (0.5×1.0×15 cm) made of Norway spruce (Picea abies) were vacuum-impregnated with copper-, chromium-, and copper-ethanolamine-based aqueous solutions (cCu=0.5%), and afterwards exposed to copper-sensitive Gloeophyllum trabeum and copper-tolerant Antrodia vaillantii for various times, between one and eight weeks. After incubation, specimens were isolated, and modulus of elasticity (MOE) losses determined using a nondestructive technique. Mass losses, FTIR spectra, and color changes were measured as well. The results showed that there is significant difference between brown rot decay caused by G. trabeum and A. vaillantii. Decay caused by A. vaillantii is more selective than that caused by G. trabeum. Additionally, it was proven that copper effectively protected spruce from G. trabeum, but not completely against A. vaillantii. Decay of copper-impregnated wood by copper-tolerant fungi is similar to decay of control, unimpregnated wood. Whereas decay of copper-impregnated specimens by G. trabeum, was effectively stopped in its initial stage.
M Humar, B Bucar, F Pohleven