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Types of decay observed in CCA-treated pine posts in horticultural situations in New Zealand
1984 - IRG/WP 1226
The few reported failures of 11-12-year-old horticultural posts in New Zealand in 1982 were caused by brown-rot. A subsequent survey of CCA-treated posts in all the major horticultural areas has revealed decay of many posts. A microscopic examination of these posts has shown decay by brown-rot, white-rot, soft-rot and bacteria. Several types of bacterial decay have been observed.
J A Drysdale, M E Hedley


A new concept of oxalic acid biosynthesis in physiology of copper-tolerant brown-rot fungi
2001 - IRG/WP 01-10394
Recently, a wide variety of roles of oxalic acid (oxalate) in wood decay systems have been receiving much attention. Copper tolerance of wood-rotting basidiomycetes has been believed to be due to the detoxification of copper wood preservatives by oxalate produced by these fungi. However, biochemical mechanism of oxalate biosynthesis in relation to physiology of wood-rotting fungi has not been elucidated although two oxalate-forming enzymes, oxaloacetase and glyoxylate dehydrogenase, have been studied in our laboratory. Recently, a new role of glyoxylate cycle in oxalate biosynthesis in wood- rotting fungi has been presented, and the cycle commonly occurred to varying extents among the fungi although they were grown on glucose. Enzymatic analyses showed that isocitrate was cleaved by isocitrate lyase in the glyoxylate cycle rather than oxidized by isocitrate dehydrogenase in tricarboxylic acid (TCA) cycle, and the fungi were found to lack a normal TCA cycle due to the absence of - ketoglutarate dehydrogenase. It is noteworthy that glucose was efficiently converted to oxalate in a theoretical yield of about 80%, accumulating in the culture media of F. palustris. The results further indicate that acetyl-CoA derived from glucose was not completely oxidized to CO2 in TCA cycle but was mainly converted to oxalate with help of the other coupling metabolic cycles, including glyoxylate cycle. Formation of oxalate from several intermediary metabolites using cell-free extracts of F. palustris confirmed that oxalate is also the final product of the metabolic pathway in the in vitro system. Thus, it is proposed as a new concept that most of copper-tolerant brown-rot fungi may acquire the energy by oxidizing glucose to oxalate, i.e. oxalate fermentation expressed in the following equation; Glucose + 5O2 --> 2 Oxalate + 2CO2 + 4H2O.
E Munir, T Hattori, M Shimada


Extracellular layers of wood decay fungi and copper tolerance
1983 - IRG/WP 1180
Extracellular layers around the hyphae of brown, white and soft rot fungi have been examined using electron microscopy. These layers were isolated for identification. Particular interest was directed towards the extracellular layers of copper-tolerant soft rot fungi.
D M Francis, L E Leightley


Copper based water-borne preservatives: The biological performance of wood treated with various formulations
1987 - IRG/WP 3451
Wood samples treated with the various components of CCA preservative singly and in combination were tested against a soft rot organism, a copper tolerant brown rot organism and in soil burial both unleached and after leaching. The results suggest that, of the elements tested, fixed copper is essential for preventing soft rot attack and fixed arsenic is essential for preventing attack by a copper tolerant brown rot organism in leaching environments.
S M Gray, D J Dickinson


Oxalic acid production of fifteen brown-rot fungi in copper citrate- treated southern yellow pine
2001 - IRG/WP 01-10388
Non-arsenical copper-based wood preservatives have grown in number since the 1980's as a response to environmental concerns posed by arsenicals. Interest in copper tolerant decay fungi has increased accordingly. Oxalic acid (OA) production by brown-rot fungi has been proposed as one mechanism of copper tolerance. Fifteen brown-rot fungi representing the genera Postia, Wolfiporia, Serpula, Gloeophyllum, Laetiporus, Coniophora, Antrodia, and Tyromyces were evaluated for OA production bi- weekly in southern yellow pine (SYP) blocks treated with 1.2% AI copper citrate (CC). Ten fungi were designated copper tolerant and produced 2 to 17 times more OA in the CC-treated blocks than in untreated SYP after 2 weeks. Weight losses ranged from 20 to 55% in CC-treated SYP after 10 wks. Five fungi were copper-sensitive, producing low levels of OA and low weight losses on CC-treated blocks. In this study, early induction of OA appears to closely correlate with copper tolerance. We conclude that brown-rot fungi able to exceed and maintain an OA concentration of >400 mM in this study effectively decayed SYP treated with copper citrate.
F Green III, C A Clausen


CCA modifications and their effect on soft rot in hardwoods. Part 2
1983 - IRG/WP 3244
The work outlined in this document is a continuation of that presented in Document No: IRG/WP/3201. The findings described in the previous paper are summarised below: a double treatment of CCB followed by arsenic (CCB+A) is more effective than a double treatment of boron followed by CCA (B+CCA) or a single treatment of CCA, CCB or CCAB in controlling soft-rot due to Chaetomium globosum in birch. CCB+A is as effective as the other formulations in controlling Coniophora puteana and Coriolus versicolor in birch and scots pine. CCB fails to copper tolerant basidiomycetes such as Coniophora puteana (F.P.R.L. 11E). A further investigation into the relative activities of CCA and CCB+A was carried out in a soil-bed using loss in strength and loss in weight as the criteria of decay. At the same time some aspects of the chemical nature of the formulations were examined in an attempt to explain the different performances of the treatments in birch. Amongst these tests, gross chemical analysis of the treated woodblocks and observation of the progressive fixation of the preservatives were the most significant.
S M Gray, D J Dickinson


Susceptibility of CCB treated wood to fungal colonization
2003 - IRG/WP 03-10492
CCB treated wood is generally resistant to all wood decay fungi. However, like CCA impregnated wood, susceptibility of CCB treated wood to copper tolerant fungi have been observed. The ability of various brown rot fungal hyphae to penetrate and overgrow the wood samples was investigated. Samples made of Norway spruce (Picea abies) were impregnated with 5 % CCB solution according to the EN 113 procedure. After conditioning, part of the samples was leached according to the EN 84 method. Small stick of unimpregnated wood (r = 1.5 mm, l = 25 mm) was inserted into a hole, bored in the center of the samples, and after that sealed with epoxy coating. Sterilized, leached and non-leached impregnated and unimpregnated specimens were exposed to two copper-tolerant (Antrodia vaillantii, Leucogyrophana pinastri) and two copper sensitive (Poria monticola, Gloeophyllum trabeum) brown rot fungi for one, two or four weeks. After exposure, the inserted wood pieces were removed from the specimens and put onto nutrient medium in petri dishes. Growth of the hyphae from those wood pieces was then visually determined. Rate of colonization by the fungi were determined by measurement of CO2 production. After that, mass losses of parallel specimens were also determined. The fastest colonization of the unimpregnated specimens was by G. trabeum (one week). On the other hand, no fungal growth could be detected on non-leached CCB impregnated specimens even after four weeks of exposure. However, significantly more intense colonization by the copper tolerant fungi were detected on the leached CCB treated samples.
F Pohleven, U Andoljsek, P Karabegovic, C Tavzes, S A Amartey, M Humar


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


Serpula lacrymans, The Dry Rot Fungus and its Tolerance towards Copper-based Wood Preservatives
2005 - IRG/WP 05-10555
Serpula lacrymans (Wulfen : Fries) Schröter, the dry rot fungus, is considered the most economically important wood decay fungus in temperate regions of the world i.e. northern Europe, Japan and Australia. Previously copper based wood preservatives were the most commonly used preservatives for pressure treatment of wood for building constructions. Because of a suspicion about tolerance toward copper components, a soil block test was undertaken to clarify the effect of two copper based preservatives, copper citrate and ACQ-D, on the dry rot fungus, Serpula lacrymans compared to an alternative non-copper containing wood preservative. The extensive use of copper-based wood preservatives has hastened the need for understanding why some fungi are able to attack copper-treated wood. The copper tolerance of S. lacrymans and other brown-rot fungi is thought to be due in part to oxalic acid production and accumulation. Oxalic acid has been implicated in copper tolerance by the formation of copper oxalate crystals. Twelve isolates of the dry rot fungus, S. lacrymans and four other brown rot species were evaluated for weight loss on wood treated with 1.2% copper citrate, 0.5% ACQ-D and 0.5% N’N-naphthaloylhydroxylamine (NHA). Eleven out of 12 S. lacrymans were shown to be tolerant towards copper citrate. ACQ-D and NHA, on the other hand, were both effective against the dry rot isolates. These wood preservatives are less toxic toward the environment than traditional copper based preservatives.
A C Steenkjær Hastrup, F Green III, C A Clausen, B Jensen


IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 21: Report of eighth inspection (7 years) in Australia
1985 - IRG/WP 4119
This report tabulates the seven year (86 month) inspection results, obtained on 28 Fabruary l985, of the IRG/COIPM International Marine Test at Goat Island, Australia. This test was installed in December 1977. The results are given in Tables 1-6. Table 7 lists the number of marine borers identified from blocks (2 cm and 6 cm long respectively) cut from the ends of specimens removed at the previous inspection, i.e. after 72 months. At that inspection the central portion of the specimens removed from test were used for chemical analysis, and bacterial and soft rot assessment by various IRG researchers. Limnoria quadripunctata has been previously identified from other timbers treated with copper-containing preservatives (Barnacle et al., 1983). Limnoria indica had not been identified previously from Australia, and this occurrence together with additions to the description of the borer, will be given by Cookson (in preparation).
L J Cookson, J E Barnacle


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


Biological detoxification of wood treated with salt preservatives
1992 - IRG/WP 92-3717
The use of microorganisms that are capable to convert chemically fixed inorganic preservative complexes from impregnated wood waste into watersoluble components is investigated. A number of fungi were isolated from deteriorated and initially well-treated wood. They revealed an exceptionally high production of organic acids (pH 2). The fungi were identified and used together with others of the same genus for experiments under non-sterile conditions on a laboratory scale with CCA-, CCB and CC-treated wood at retention levels of at least 50% higher than recommended for wood in ground contact. As a result Cr and As were leached to more than 90% depending on culture conditions, whereas Cu reacts with oxalic acid to a complex with limited water solubility.
I Stephan, R-D Peek


Tolerance of Wood Decay Fungi to Commercial Copper Based Wood Preservatives
2002 - IRG/WP 02-30291
Due to the use of copper based preservatives like CCB or CCA for more than a century, copper tolerant fungi have appeared in some European countries in recent times. It is therefore important to find out whether this phenomenon is specific for only classical copper ingredients, or generally for all copper based formulation. Thus, we tested the tolerance of three commercial copper based preservatives and copper(II) sulphate as well as potassium dichromate for comparison. In this research, seven copper tolerant Antrodia isolates and copper intolerant fungus Gloeophyllum trabeum were tested using a screening test and standard laboratory test SIST EN 113. Screening test were performed on potato dextrose agar (PDA) with copper concentration between 5.0×10-4 and 2.5×10-2 mol/l. The tolerance determined by the screening test was not always comparable with results obtained with the standard laboratory test. However, results obtained on wood samples showed that various fungal isolates exhibited different levels of copper tolerance depending on the copper based biocide. Tolerant strains were able to decay copper sulfate as well as copper naphthenate preserved wood samples. On the other hand, even the most tolerant fungi could not decompose wood preserved with classical CCB or copper amine preservative. It can therefore be concluded that various fungal isolates exhibited different copper tolerance regarding copper formulations. This finding is very important for remediation of waste treated wood by fungi. For a successful detoxification of waste wood impregnated with multi salt preservatives like CCA or CCB the suitable tolerant fungal strains have to be used, simultaneously for synergistic action.
F Pohleven, M Humar, S A Amartey, J Benedik


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. There has been a suggestion that copper tolerance had more to do with lowering of the pH of the substrate rather than the low solubility of copper oxalate. In order to elucidate this presumption CCB treated wood samples were acidified with organic (oxalic, acetic, lactic, formic) and inorganic (sulphuric) acids and afterwards exposed to copper tolerant (Antrodia vaillantii, Leucogyrophana pinastri) and copper sensitive (Poria monticola, Gloeophyllum trabeum) brown rot fungal strains according to the mini block procedure. After eight weeks of exposure, the samples were isolated and their mass losses were determined. In addition, electron paramagnetic resonance (EPR) measurements on the exposed samples were performed. The EPR spectra of the samples decayed by A. vaillantii were very similar to those of the samples acidified with oxalic acid. Furthermore, acidification of the CCB impregnated samples made them significantly more susceptible to copper tolerant and copper sensitive brown rot fungi what can be clearly seen from weight losses.
M Humar, S A Amartey, M Šentjurc, F Pohleven


The Copper Tolerance of Mycelium vs. Spores for Two Brown Rot Fungi
2002 - IRG/WP 02-10422
The copper tolerance of two brown rot fungi, Gloeophyllum sepiarium and Oligoporus placentus, has been tested using both mycelia and basidiospores as inoculum sources. Mycelial growth of O. placentus on agar medium was shown to be much more tolerant to copper (as copper sulfate) than that of G. sepiarium. However, there was no difference in copper tolerance of basidiospores between the two species. Spores were much more sensitive to copper than mycelia in both species. This may explain why copper-based preservatives without co-biocide perform well in stake tests unless there is copper tolerant fungi mycelium in the soil.
S Choi, J N R Ruddick, P I Morris


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.
O Schmidt


Working plan: Second international collaborative field trial
1995 - IRG/WP 95-20056
This paper describes the scope, objectives, and approaches to be used in the second international collaborative field trial approved by the Scientific Programme Committee for partial funding in 1994. The trial is designed to develop a broad data base on causal mechanisms, interactions, and factor affecting the performance of treated wood in ground contact. The trial encompasses 12 different field test sites representing all continents except Antarctica. Preservatives were chosen to represent new technologies and include oilborne, waterborne copper-organic, and water-dispersible systems. CCA is used as the reference system. Task forces to research the following areas are described: accelerated soilbed testing, decay types/modes of failure, preservative depletion, abiotic factors, and copper tolerance.
H M Barnes, T L Amburgey


The effect of copper/chrome/arsenic (CCA) treated timber on soil fungi
1981 - IRG/WP 1131
The aim of this investigation was to study the effect of CCA treated wood on the microflora of soil with particular reference to copper tolerant soft rot fungi. The IRG collaborative field experiment was designed to monitor the performance of a range of preservative treated hardwoods with particular reference to soft rot in CCA treated timber (Dickinson 1976) and site 33 of this experiment was used in this investigation. The results clearly show that CCA impregnated timber affects the mycoflora of adjacent soil leading to increased frequency of isolation of copper tolerant fungi and particulary Phialophora spp.No significant increases in occurrence of copper tolerant fungi were noted in soil 1 cm from the wood surface indicating that the effect of treated timber is confined to a small area of soil.
R J Murphy, D J Dickinson


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


Limnoria quadripunctata Holthuis - a threat to copper-treated wood
1983 - IRG/WP 4100
This paper presents the first reported attack by the crustacean marine wood-borer Limnoria quadripunctata Holthuis of CCA treated eucalypt piles. The attack occurred after 12 years service of the piles in the River Derwent at Hobart, Tasmania. Attack by both this borer and Limnoria tripunctata Menzies is also reported in CCA treated softwoods and hardwoods over periods ranging from 5 to 22.9 years in Sydney Harbour. No estimate of the relative importance of the two borers in CCA treated wood at the Sydney site could be made. Chemical analyses of some of the attacked wood specimens is provided.
J E Barnacle, L J Cookson, C N McEvoy


Influence of fungal exposure on the redistribution of copper in treated spruce wood
2002 - IRG/WP 02-10450
The redistribution of copper in treated wood after exposure to basidiomycete decay fungi is described. The micro-distribution of copper in copper(II) sulphate or copper(II) octanoate/ethanolamine treated Norway spruce wood before and after exposure to 3 different wood decay fungi was studied using transmission electron microscopy with X-ray microanalysis. The copper content of the mycelium and the nutrient medium was also determined by atomic absorption spectroscopy. Finally, light microscopic analyses of decayed samples was performed. Both copper-tolerant (Antrodia vaillantii) and copper-sensitive fungi (Trametes versicolor and Gloeophyllum trabeum) changed the distribution of copper in the treated wood after 16 weeks of exposure. The redistribution of copper in copper sulphate treated samples exposed to tolerant A. vaillantii was characterised by the excretion of oxalic acid and formation of copper oxalate in the cell lumens, on the surface of treated wood blocks and on the fungal hyphae. In the presence of ethanolamine, the formation of copper oxalate by A. vaillantii did not occur but instead diffusion of copper into regions of lower copper concentration (centre of the blocks and nutrient medium) took place. This type of redistribution/diffusion of copper was also observed when treated wood specimens were exposed to the copper-sensitive fungi.
M Humar, F Pohleven, R J Murphy, D J Dickinson, I Moris, M Zupancic, P Kalan, M Petric


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


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