Your search resulted in 109 documents. Displaying 25 entries per page.
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
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
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
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
Extracellular carbohydrate production by isolates of Postia (=Poria) placenta
1989 - IRG/WP 1388
A monokaryotic strain of Postia (=Poria) placenta, ME20, which is unable to degrade wood, also failed to produce extracellular polysaccharide when grown in liquid culture, regardless of carbon source or concentration. Other isolates of Postia placenta, including another monokaryon and a hybrid of this monokaryon with ME20, produced large quantities of this material. The polysaccharide consisted pr...
J A Micales, A L Richter, T L Highley
Production of fungal protoplasts from selected wood-degrading fungi
1991 - IRG/WP 1500
Studies of hyphal morphology and the effects of various chemicals on growth are often difficult to perform on filamentous fungi because of the difficulty of observing the protoplasm through the rigid hyphae wall and because most activity occurs in a limited region near the hyphal tip. As an alternative, hyphae can be reacted with certain cell wall degrading enzymes to remove the cell wall to produ...
C Rui, J J Morrell
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 ...
T L Highley
Natural durability of tamarack (Larix laricina (Du Roi) K. Koch)
1998 - IRG/WP 98-10277
Eastern larch or tamarack (Larix laricina (Du Roi) K. Koch) lumber from New Brunswick, Canada was evaluated for heartwood natural durability according to ASTM D2017-81. The natural durability of tamarack heartwood exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta was low and generally inferior to that of the heartwood of spruce (Picea sp.) and white pine (Pinus strobus L.) a...
U Srinivasan, A Taylor, P A Cooper
The role of oxalic acid in short fiber formation by the brown-rot fungus Postia placenta
1993 - IRG/WP 93-10028
The mechanism by which brown-rot fungi depolymerize wood and cellulose remains a perplexing problem. Current evidence favors oxidation by low-molecular weight, non-enzymatic fungal metabolites. During attack of cotton cellulose by Postia placenta MAD-698, the degree of polymerization (DP) decreases to limit of degree of polymerization (LODP) over a period of 5-6 weeks with relatively low weight lo...
F Green III, J M Hackney, C A Clausen, M J Larsen, T L Highley
Assessment of the Envelope Effect of Three Hot Oil Treatments: Resistance to Decay by Coniophora puteana and Postia placenta
2006 - IRG/WP 06-40344
Timber of Corsican pine (Pinus nigra var. maritima) and Norway spruce (Picea abies) was treated in hot linseed oil, rapeseed oil and a proprietary resin derived from linseed oil. The samples were immersed in oil or resin under reduced pressure at temperatures of 180°C and 200°C. Very high uptakes of the oils or resin were recorded for pine, while spruce showed lower weight percent gains, below...
M J Spear, C A S Hill, S F Curling, D Jones, M D C Hale
Effect of ozone treatment on survival of termites and wood decay fungi
2007 - IRG/WP 07-40365
There is increased concern about the potential for transport of invasive pests on or in untreated wood. Current regulations utilize heating or fumigation as mitigation tools, but both have drawbacks that have stimulated interest in new phytosanitation methods. Ozone fumigation has been shown to control insects, fungi and bacteria on a variety of agricultural products. Systems for the controlled g...
A M Taylor, L J Mason, J J Morrell
Postia placenta gene expression of oxidative and carbohydrate metabolism related genes during growth in furfurylated wood
2009 - IRG/WP 09-10701
A range of studies the last decade have shown that modified wood can provide excellent protection against a range of wood deteriorating organisms, including decay fungi. However, we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward e.g. inhibition of action of specific enzymes, but they still need testing. An understandi...
G Alfredsen, C G Fossdal
Laboratory and above ground exposure efficacy of silicon-boron treatments
2009 - IRG/WP 09-30510
The study deals with silicon compounds, namely tetraethoxysilane (TEOS), phenyltriethoxysilane (PhTES) and methyltriethoxysilane (MTES) at concentrations of 23, 16 and 10% in combination with 1.2-1.5% boric acid. The aim with the study was to combine the chemical approach with the necessary biological tests of the impregnated wood. The tested silicon-boron combinations ensured mass loss less than ...
N Terziev, D Panov, A Temiz, S Palanti, E Feci, G Daniel
Postia placenta gene expression during growth in furfurylated wood
2010 - IRG/WP 10-10734
Modified wood can provide protection against a range of wood deteriorating organisms. But we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward for the mode of action against wood decaying fungi, including inhibition of action of specific enzymes, but they still need further testing. In this study gene expression of the b...
G Alfredsen, C G Fossdal
Measurements of rot fungal activity as a function of moisture content by isothermal calorimetry
2010 - IRG/WP 10-20428
Measurements of heat production rate have been made on wood samples with the brown rot fungus Postia placenta at different moisture contents. The results clearly indicate that the heat production rate (a measure of respiration rate and activity) is moisture dependent. When the moisture content is decreased, less heat is produced, and when the moisture content is increased, more heat is produced. I...
L Wadsö, A Pilgård, G Alfredsen
The effects of acetylation level on the growth of Postia placenta
2011 - IRG/WP 11-10751
To understand the defence mechanisms utilized by decay fungi when exposed to different wood protection systems the study of gene expression can give us some answers. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by differen...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
Molecular investigation of Postia placenta growing in modified wood
2011 - IRG/WP 11-10756
Brown rot is the most common and destructive type of fungal decay for wood in service. These fungi depolymerize preferentially the structural carbohydrates, cellulose and hemicellulose in the cell wall leaving oxidized lignin behind. Modified wood can provide protection against a variety of wood deteriorating organisms, including decay fungi. However, there is still little known about the mode of ...
B Schmöllerl, G Alfredsen, C G Fossdal, M Westin, A Steitz
Variation in two Postia placenta strains, MAD-698-R and FPRL 280 – mass loss, DNA content and gene
2012 - IRG/WP 12-10781
Brown-rot fungi such as Postia placenta are common inhabitants of forest ecosystems and brown rot fungi are also largely responsible for the destructive decay of wooden structures. The aim of this study was to compare two commonly used strains of Postia placenta – MAD-698-R and FPRL 280. Scots pine sapwood samples were exposed for two and eight weeks to both fungal strains. The following was inv...
N Thaler, G Alfredsen, C G Fossdal
The effects of acetylation level on the growth of Postia placenta over 36 weeks
2012 - IRG/WP 12-40589
Genomic sequencing gives us a tool to systematically and rapidly discover novel genes, how their products function in the cell, and explore their interactions. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by different wood...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
The activity of a wood-decaying fungus during drying and rewetting cycles measured by isothermal calorimetry
2013 - IRG/WP 13-20526
Wood decaying fungi are an essential part of any ecosystems as they are the main decomposers of cellulose and lignin-containing materials. But as wood is a common building material the risk for decay fungi growth and subsequent degradation of our construction material is a concern. There are important physiological aspects of the growth and activity of decay fungi that are unknown today, and witho...
S Johansson, L Wadsö, A Pilgård, G Alfredsen
Preliminary testing of spiroborate esters as wood preservatives
2013 - IRG/WP 13-30614
Fungicide and insecticide properties of boric acid are known since 30’s of the last century, but high solubility and leachability of inorganic borates limit their use for only applications not directly exposed to liquid water. A number of attempts were made to fixate borate salts into the wood structure but this research topic is still up to date and undiscovered. Water insoluble organoboron est...
D Panov, N Terziev
Postia placenta cellulase gene expression in modified wood during incipient decay
2013 - IRG/WP 13-40626
In optimization of modified wood, it is important to understand the mode of action of the wood modification and how the fungi response to it. The aim of this study was to investigate the expression of cellulases during the first two weeks of Postia placenta exposure in acetylated, DMDHEU-treated and thermally modified as well as in untreated wood. Using real-time PCR, the gene expression patterns ...
R Ringman, A Pilgård, K Richter