Your search resulted in 108 documents. Displaying 25 entries per page.
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
The role of oxidation in wood degradation by brown-rot fung
1992 - IRG/WP 92-1562
Brown-rot fungi are suggested to degrade cellulose by oxidation with hydrogen radicalsformed eg. in the conversion of hydrogen peroxide in the Fenton type reactions. The stuctural changes in the holocellulose in wood induced by Fenton's reaction on wood components are very similar to those caused by brown-rot fungi. In this work the effect of the Fenton reaction on wood components was stu...
A-C Ritschkoff, J Pere, J Buchert, L Viikari
Effect of some resin treatments on fungal degradation reactions
1999 - IRG/WP 99-10318
The effect of impregnation of wood with vegetable oil, tall oil and two water soluble on fungal degradation reactions was assessed by hydrolysis and enzyme activity measurements. The experiments were carried out by using isolated enzyme preparations and a living brown-rot fungus Poria placenta. The results indicate that the inhibitory effect of treatments was clearly directec towards the enzymatic...
A-C Ritschkoff, M Rättö, A J Nurmi, H Kokko, A O Rapp, H Militz
Toxic values derived from EN 113 tests - are they determined by the virulence of a test fungus?
- Results from a round robin test -
1999 - IRG/WP 99-20176
The virulence of Coniophora puteana BAM Ebw. 15, the obligatory test fungus on softwood in tests according to EN 113, is known to be rather inconstant at least in some laboratories. The mass losses of untreated Scots pine sapwood blocks in an EN 113 test may range from below 20% to up to more than 50%. Possible reasons for these differences as well as the impact of a low virulence on the toxic val...
H Leithoff, R-D Peek, H V Borck, R Goettsche, H Kirk, M Grinda
Differences in pH, electrical resistance, cation composition and NIR spectra of red spruce wood during early stages of brown rot degradation
2002 - IRG/WP 02-10449
Red spruce sapwood was exposed to degradation by the brown rot fungi Coniophora puteana, Postia placenta, Gloeophyllum trabeum and Serpula lacrymans for 0, 1, 2 or 3 weeks using a modified soil block assay design. Average weight losses over time ranged from 0-8.9% during this time period. Detectable changes in pH, electrical resistance and cation compostion were observed in the wood as early as 1 ...
J Jellison, S Kelley, B Goodell, D Hui, A Ostrofsky
Regulation of hyphal sheath formation iron-chelator production by the brown rot fungi Gloeophyllum trabeum and Postia placenta
1994 - IRG/WP 94-10074
Hyphal sheath formation and iron-chelator production by liquid cultures of the brown rot fungi Gloeophyllum trabeum and Postia placenta were monitored over time. The effects of incubation at various temperatures, pH's and concentrations of iron, manganese and nitrogen were determined. Hyphal sheath production was observed microscopically and quantified with JAVA video analysis. The hyphal...
Y Chen, J Jellison
Properties of cellulose degraded by the brown rot fungus, Postia placenta
1988 - IRG/WP 1350
To gain further understanding of the nature of the cellulose depolymerizing agent or agents of brown-rot fungi, brown-rotted cellulose was chemically and physically characterized. Various culture conditions, such as low nitrogen and elevated oxygen levels, did not induce degradation of cellulose by Postia placenta in liquid cultures. Therefore, brown-rotted cellulose for analysis was prepared by a...
T L Highley, R E Ibach, T K Kirk
Dimensional stabilization and decay resistance of wood treated with brown-rotted lignin and copper sulfate
1990 - IRG/WP 3608
The objective of this study was to evaluate the potential usefulness of brown-rotted lignin (BRL) as a dimensional stabilization and copper complexing agent for wood treatment. For dimensional stabilization, aqueous solutions of the lignin extract were combined with either copper sulfate, glyoxal or other additives. Anti-shrink efficiency (ASE) values as high as 42% were obtained with wood treated...
L Jin, D D Nicholas, T Schultz
Silicon tetrachloride: A potential wood preservative
1980 - IRG/WP 3133
In its present form, this paper is a preliminary draft of a paper that will eventually be submitted for publication in the Forest Products Journal. We are continuing the work on the effects of silicon tetrachloride on wood and expect to have additional data for the meeting in May 1980. Specifically we are measuring the penetration rate and depth of SiCl4, and we are chemically analyzing the treate...
C W Owens, W T Shortle, A L Shigo
The nature of osmiophilic particles and their distribution during different stages of brown and white rot decay
1983 - IRG/WP 1213
The distribution of osmiophilic particles during the course of brown and white rot decay was investigated by applying transmission electron microscopic (TEM) methods. It was found that it correlates with the brown and white rot pattern.The osmiophilic particles are produced by the fungus and are supposed to be wood rotting enzymes....
K Messner, H Stachelberger
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 p...
O Schmidt
Effect of crude tall oil, linseed oil and rapeseed oil on the growth of the decay fungi
2002 - IRG/WP 02-30299
The influence of crude tall oil, linseed oil and rapeseed oil on the growth of Coniophora puteana, Poria placenta and Coriolus versicolor was studied. The selected test oils were observed to have different effects on the the fungal growth. Crude tall oil inhibited the radial growth of all fungi. Rapeseed oil either accelerated or inhibited the growth of fungi depending on the type of fungus involv...
L Paajanen, A-C Ritschkoff
Screening wood preservatives: Comparison of the soil block, agar block and agar plate tests
1993 - IRG/WP 93-20001
Several test procedures have been developed over the years to screen potential biocides for their value as wood preservatives. Each test has inherent advantages and disadvantages. In this paper the relative merits of the soil block, agar block and agar plate tests are compared. Eight commercially available biocides encompassing inorganic and organic systems were tested against four basidiomycete d...
K J Archer, D D Nicholas, T Schultz
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...
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 present...
O Schmidt, U Moreth
The production of extracellular hydrogen peroxide by some brown-rot fungi
1990 - IRG/WP 1446
The role of hydrogen peroxide (H2O2) has been discussed in the degradation of wood by wood-rotting fungi. The production of extracellular hydrogen peroxide was studied by detecting the oxidation of the chromogen 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) by H2O2 and horse radish peroxidase (HPR). ABTS and HPR were added to a solid wood based culture media. In this study ...
A-C Ritschkoff, L Paajanen, L Viikari
Immunolocalization of extracellular metabolites from Poria placenta
1988 - IRG/WP 1361
Polyclonal antisera produced to Poria placenta extracellular metabolites was used in immuno-fluoresence microscopy and immuno-gold TEM studies. In the fluorescence work, labelling of Poria placenta hyphae in wet fixed wood material was observed but not in infected wood which was oven dried prior to sectioning and immunolabelling. TEM studies provided better resolution, with gold labelling detected...
B Goodell, G F Daniel, J Jellison, T Nilsson
Cation analysis of wood degraded by white and brown rot fungi
1992 - IRG/WP 92-1552
Changes in the concentrations and composition of cations within wood colonized by the brown-rot fungi Postia placenta and Gloeophyllum trabeum and the white-rot fungi Trametes versicolor and Phanaerochaete chrysosporium were analyzed using plasma emission and atomic absorption spectrophotometry. In degraded poplar wood significant decreases in pH and electrical resistance readings were observed as...
J Jellison, K C Smith, W T Shortle
Effects of chemical pretreatment of Douglas-fir heartwood on efficacy of potential bioprotection agents
1990 - IRG/WP 1440
Biological protection against wood decay fungi represents an environmentally attractive alternative to the use of chemicals; however, the process of identifying suitable candidates and the conditions that ensure successful protection pose major challenges. One critical aspect of this problem is to identify organisms that can rapidly and uniformly colonize the wood. Wood contains low levels of nutr...
B Dawson-Andoh, J J Morrell
Co-operative studies on determining toxic values against wood-destroying basidiomycetes: Progress report to April 1990
1990 - IRG/WP 2357
This document reports progress on the co-operative study between nine laboratories, set up following the proposals contained in Document IPG/WP/2316 (1988). Results have been received from eight laboratories. Toxic values data have been established successfully for the test fungus Coniophora puteana with soil, malt agar and vermiculite methods and with the test fungi Gloeophyllum trabeum and Poria...
J K Carey, A F Bravery
Enzyme immunoassay to detect Postia placenta in field tests: Comparison of plate ELISA with hydrophobic cloth and cotton dipstick
1991 - IRG/WP 2378
Standard indirect enzyme-linked immunosorbent assay in polystyrene 96-well plates was compared to hydrophobic polyester cloth and cotton dipstick for detection of wood-derived antigens from the brown-rot fungus Postia placenta. The ease of handling, larger surface area, and economics of the latter two adsorbents were surveyed for application as field tests for detection of early decay. At high ant...
C A Clausen
Method to determine the depth of penetration of the biologically active components of wood preservatives
1978 - IRG/WP 2108
A time-saving method for determining the depth of penetration of the biologically active components of wood preservatives is described. The test specimens were obtained by cutting thin slices from the wood either parallel or perpendicular to the treated surface. The slices were then exposed to fungal attack. A good correlation was found between the test results obtained by the modified German Stan...
H-P Sutter
Oxalic acid metabolism of Postia placenta
1992 - IRG/WP 92-1566
The oxalic acid metabolism of Postia placenta was studied in liquid culture in order to identify the metabolic pathways of biosynthesis and to determine whether oxalic acid physiology could be correlated with efficiency in wood decay. Oxalic acid production was determined for test strain MAD698 grown in a basal defined medium with a variety of different carbohydrate and nitrogen sources. The highe...
J A Micales
Immuno-scanning electron microscopic localization of extracellular polysaccharidases within the fibrillar sheath of the brown rot fungus Postia placenta
1991 - IRG/WP 1497
Extracellular polysaccharidases of the brown-rot fungus Postia placenta were localized using colloidal gold labeled monoclonal antibodies to the B-1,4-xylanase (32-36kDa) fraction of Postia placenta. Postia placenta was grown from agar onto glass coverslips, immunolabeled with or without prior fixation, and examined by SEM. Enzymes were localized on the hyphal surface and on the clumped fibrillar ...
F Green III, C A Clausen, M J Larsen, T L Highley
The effect of Tween 80 on the growth, morphology, and enzyme secretion of Postia placenta
1990 - IRG/WP 1456
The nonionic surfactant Tween 80 (polyethylene oxide sorbitan mono-oleate) has been reported to increase enzyme production and/or secretion in bacteria and fungi. Such a procedure could greatly facilitate research into the physiology of wood-decay fungi since quantities of available enzyme are often limiting. The brown-rot fungus Postia placenta was grown in a synthetic medium supplemented with 0,...
J A Micales