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Growth of two selected sapstain fungi and one mould on chitosan amended nutrient medium
2003 - IRG/WP 03-10466
In vitro studies were undertaken to investigate the effect of chitosan on growth of Leptographium procerum, Sphaeropsis sapinea and Trichoderma harzianum. Chitosan was tested at three molecular weight (MW) ranges and different concentrations formulated as either a powdered suspension or as a solution. The results generally showed that low MW chitosan produced a greater inhibitory effect on growth of test fungi than medium and high MW, irrespective of the chitosan formulation used. However, chitosan was more effective when applied in solution with much lower concentrations exerting inhibition of test fungi than chitosan suspensions. Furthermore, susceptibility of test fungi to chitosan differed, with T. harzianum being the most tolerant and S. sapinea the most sensitive species irrespective of chitosan formulation used.
C Chittenden, R N Wakeling, B Kreber

In vitro studies on the effect of chitosan on mycelial growth and spore germination of decay fungi, moulds and staining fungi
2004 - IRG/WP 04-10507
The effect of solubilised, low molecular weight chitosan on established mycelial growth of a range of decay fungi, moulds and staining fungi was investigated using nutrient medium amended with different concentrations of chitosan that ranged from 0.1 to 0.4% weight per volume (%w/v). Also, spore germination of Trichoderma harzianum and Leptographium procerum was examined on chitosan amended nutrient medium using visual and microscopic assessment. The results showed that chitosan affected mycelial growth of a wide range of test fungi which generally showed lower growth rates as the chitosan concentration increased. However, the degree of inhibition exhibited by chitosan varied with fungal species. Under the present test conditions, chitosan was fungistatic, but not fungitoxic, against established mycelium of the staining fungi tested and also two moulds, Botrytis cinera and Cladosporium herbarum, but not against any of the decay fungi tested. Spores of T. harzianum germinated on chitosan amended nutrient medium at all chitosan concentrations tested, except for the highest level (0.2%w/v) used, while L. procerum failed to germinate on 0.15 and 0.2%. Also, T. harzianum and L. procerum spores incubated on 0.15% and 0.2% chitosan failed to germinate when placed onto fresh malt extract agar suggesting fungitoxic activity of chitosan at these higher concentration levels.
C Chittenden, B Kreber, N McDowell, T Singh

Ibuprofen inhibits in vitro growth of brown-rot fungi
1996 - IRG/WP 96-10160
Ibuprofen, a phenyl propionic acid derivative (2-(4-isobutylphenyl)propionic acid) inhibited growth in vitro of 17 brown-rot fungi at a concentration of 100 µg/mL, while exhibiting no growth inhibition for 8 white-rot fungi at the same concentration. Propionic acid did not inhibit fungal growth in vitro. Morphological changes were noted in fungi that were able to grow in the presence of ibuprofen.
C A Clausen

Comparison of the effects of borate, germanate and tellurate on fungal growth and wood decay
1992 - IRG/WP 92-1533
The tetra-hydroxy borate ion is known to undergo complexation with polyols and has been shown to inhibit dehydrogenase enzymes in this way. It has been previously suggested that this complexation is responsible for the inhibition of fungal growth and the protection of boron treated timber. Other ions that have the ability to complex with polyols have also been shown to inhibit dehydrogenase activity. The effect of two of these ions on fungal growth and wood decay was compared to that of borate. It was found that both germanate and tellurate could reduce fungal growth and provide protection of wood against decay at similar molar concentrations as borate. The results have been used to further develop our understanding of the mechanisms of action of borate wood preservatives and substantiate the theory that borate ion/polyol complexation is responsible for the protection of boron treated timber.
J D Lloyd, D J Dickinson

The probable mechanism of action of boric acid and borates as wood preservatives
1990 - IRG/WP 1450
The tetrahydroxyborate ion [B(OH)4-] acts by complexation with poly-ols and probably attacks decay fungi through extracellular substrate sequestration; intracellular substrate sequestration; enzyme inhibition; and change in membrane function. Work was carried out to investigate this further and to try to explain certain phenomena observed in the area of boron preservation. The effect of Na borate in the presence of different concentrations or various carbohydrates upon the radial growth rate of certain fungi was investigated; along with parallel experiments on the activity of 6-phosphogluconate dehydrogenase as an example of a borate inhibited enzyme system. It was found that upon the addition of certain poly-ols, the inhibitory effect of borate on both fungal growth and enzyme activity could be reduced. These results have been used in the development of our understanding of the mechanism of action of borates as wood preservatives. The commonly held belief that certain mould species are resistant to borates may also need re-evaluation.
J D Lloyd, D J Dickinson, R J Murphy

Susceptibility of Lentinus lepideus (Fr.:Fr.) Fr. to volatiles produced by Trichoderma spp
1987 - IRG/WP 1316
A range of Trichoderma species and strains were tested for their ability to produce fungistatic volatiles. Volatiles from all isolates produced fungistatic effects on Lentinus lepideus however wide interspecies and interstrain variability in the level of response was evident. Cross plating studies between the Trichoderma isolates and Lentinus lepideus showed that Lentinus lepideus was overgrown and lysed by its Trichoderma competitor in all cases. The results indicate that the rate of overgrowth of Lentinus lepideus was directly related to the levels of volatiles produced by each of the Trichoderma isolates. The implications of the results on the use of Trichoderma species as biological control agents is briefly discussed.
A Bruce, C Johnstone, J A P McVey

Gaseous treatment of timber with allyl isothiocyanate. Fungicidal and insecticidal effects
1996 - IRG/WP 96-30108
Gaseous treatment with allyl isothiocyanate (AIT) was tested for its effects on the growth of microorganisms on the wood substrate and the mortality of subterranean termites and powder-post beetles. Toxic limits of AIT were determined as concentrations in the air when an AIT-treated filter paper was placed in a sealed container with fungus-inoculated wood specimens. Those were <3.8 ppm for Aureobasidium pullulans, 7.5-15 ppm for Aspergillus niger, 30-59 ppm for Gliocladium virens, 59-118 ppm for Penicillium funiculosum and >118 ppm for Rhizopus stolonifer. LD 50 values were determined for insects. Twenty workers of Coptotermes formosanus or 10 adults of Lyctus brunneus were placed in an air-circulated glass bottle, and the mortality of the test insects was recorded after 24 hours. LD 50/24h were 10-13 ppm and approximately 80 ppm in the air for Coptotermes formosanus and Lyctus brunneus, respectively.
K Tsunoda, T Yoshimura

Algal growth resistance of paints for coating of wood; a laboratory study
1997 - IRG/WP 97-10213
Twelve paints were tested for resistance against algae. In addition, one algicidal compound commercially used for remedial treatments of algal growth on paints was tested for its effectiveness for prevention of algal growth. An agar diffusion bioassay was employed in which paint films on filter paper discs were placed on mineral salt medium and sprayed with an algal suspension containing a mixture of one blue-green alga, Oscillatoria tenuis, and two green algae, Ankistrodesmus gracilis and Pleurococcus sp. Most growth was recorded in plates with discs painted with acrylic paints. Two acrylic paints containing a commercial fungicide at normal or double concentration permitted the same amount of growth as the same acrylic paint without fungicide addition. The solvent-borne alkyd paints and the alkyd emulsion paints were more inhibitory against growth of algae. Only some of the acrylic paints permitted any growth of the green alga Ankistrodesmus gracilis. Acrylic paints containing a commercial algicide inhibited the growth of the Pleurococcus sp. and Ankistrodesmus gracilis but permitted some growth of Oscillatoria on the agar medium used.
J Bjurman

Antagonistic effects of Dacrymyces stillatus against growth of other fungi
1991 - IRG/WP 2363
The antagonistic effects in dual cultures on malt extract agar of 5 wood decay fungi and the antagonistic effects of Dacrymyces stillatus against 1 mould fungus and 1 blue stain fungus were determined. Dacrymyces stillatus was the only fungus which exhibited clear antagonistic effects. The effects of Dacrymyces stillatus against the different test fungi varied however to a great extent. Dacrymyces stillatus exhibited clear antagonism against brown rot fungi and a weaker effect against a mould fungus and a blue stain fungus. The antagonistic effect against a white rot fungus was weaker in dual culture. Spore germination of the responding white rot fungus Pycnoporus cinnabarinus was completely inhibited on an agar overlay over a culture of Dacrymyces stillatus on malt extract agar. Inhibitory activity was present in extracts.
J Bjurman

Effect of amphiphilic antioxidant alkyl ammonium ascorbate on inhibition of fungal growth: Application to wood preservatives formulation
2008 - IRG/WP 08-30466
Amphiphilic surfactants were synthesized from ascorbic acid and different fatty amines and evaluated for formulation of wood preservation products. Characterization of physicochemical properties of the new compounds indicated classical behavior of cationic surfactants. Antioxidant properties, estimated using methyl linoleate oxidation inhibition method, were similar to that of ascorbic acid tested in the same conditions. Growth inhibition assays indicated that amphiphilic dodecylammonium ascorbate is able to inhibit Coriolus versicolor mycelium development, while butylammonium ascorbate deprived of surfactant properties has no effect. This compound was then investigated in the formulation of wood preservation mixtures containing propiconazole and compared to formulation obtained with an industrial surfactant. Biological tests based on the ability of these formulations to protect beech wood blocks exposed to a white rot fungus Coriolus versicolor were carried out under laboratory conditions. Results indicated that use of propiconazole formulation in aqueous solution allows to reduce the quantity of biocide compared to solutions of the same concentrations in ethanol. Protection achieved with antioxidant surfactant was slightly superior to that conferred by conventional surfactant.
C Gérardin , T Koumbi Mounanga, P Gérardin

Influence of a pulsed electric field on the growth of surface fungi
2013 - IRG/WP 13-10795
The colonization of mold and staining fungi are not only an aesthetical problem. Blue stain fungi are able to penetrate paint films. Maintenance of coatings on wood are time consuming and costly. A new approach uses a pulsed electric field (PLEOT) in order to protect wood against surface fungi. This technology is evaluated in non-sterile laboratory conditions on different coated and uncoated Scots pine sapwood and spruce wood samples exposed to a fungi mix for 12 weeks and in sterile test conditions on wood samples exposed to Aureobasidium pullulans and Ulocladium atrum for 8 weeks. The installation of PLEOT could reduce the growth of surface fungi. The addition of graphite to the coating led to significantly reduced growth of fungi on the front side of the samples using a fungi mix. The addition of graphite did not influence the growth of surface fungi. Growth of A. pullulans on the front side of wood samples in a sterile test showed to be slightly influenced by PLEOT, while growth inhibition of U. atrum was more pronounced on the back side of the wood samples.
M Starck, A Treu

Investigations on the durability of several Congo basin wood species
2015 - IRG/WP 15-10840
The sawdust of ten wood species was studied to assess their natural resistance to decay. The extractives and lignin contents were primarily determined (between 2.7-16.0% and 26.8-35.9% respectively) to give an overview of the chemical distribution. Then, a phytochemical screening (colorimetric methods) characterized the different chemical functional groups in all extracts studied. Antioxidant activity indicated values comprised between 18 and 175 µmol AAE/µg of extract correlated to total phenolic content which were comprised between 51 and 935 mg eq. of gallic acid/g of extract. The resistance to decay of extracted and unextracted sawdust against the two white-rot fungi was evaluated and showed that extractives amounts and compositions partially influenced wood durability.
S Mounguengui, J-B Tchinda Saha, M Kor Ndikontar, S Dumarçay, C Attéké, D Perrin, E Gelhaye,

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

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

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

The dry rot fungus Serpula lacrymans. Examples of attack and remedial treatment
1988 - IRG/WP 1347
The film deals with several aspects of dry rot attack and eradication in buildings. The detailed biology and morphological charasteristics of the fungus are portrayed. The various forms of mycelial growth, the role of the strands in the nourishment and spread of the fungus, as well as the many types of fruitbody formation are outlined. Environmental and nutritional requirements of the fungus as well as the potential infection danger posed by the basidiospores are discussed. The second part of the film, outlining the main reasons for dry-rot attack and spread in building together with the significant damage caused, shows the full extent of the problem to expert and lay-person alike. The necessity of correct survey and inspection of decayed areas to determine the full range of attack is stressed. Examples of various remedial treatments and the present technological state of eradication techniques, e.g. pressure injection, in Germany are discussed.
G Buchwald, B M Hegarty, W Metzner, R Pospischil, H Siegmund, P Grabow

Influence of moisture content of rubber wood on the growth of Botryodiplodia theobromae
1993 - IRG/WP 93-10029
Botryodiplodia theobromae is the main fungus causing sapstain on rubber wood (Hevea brasiliensis). The entry and establishment of the stain fungus is nighly influenced by the moisture content of the wood. To determine the optimum moisture content of wood required for maximum growth of Botryodiplodia theobromae wood blocks at different moisture contents were inoculated with the test fungus and incubated for a period of two weeks. The study showed if the moisture content of the wood was reduced to less than 24%, the wood can be protected from fungal sapstain.
E J M Florence, R Gnanaharan, J K Sharma

Targeting fungal proteinases to prevent sapstain on wood
1995 - IRG/WP 95-10097
Discoloration of wood, caused by a variety of sapstaining fungi, leads to periodic losses in the Canadian lumber export industry. Proteolytic enzymes are thought to be necessary for retrieval of nitrogen during fungal growth on wood. The major extracellular proteinase of Ophiostoma piceae, a representative sapstaining fungus, was purified to homogeneity and its inhibition pattern characterised. Classic serine proteinase inhibitors inhibited the activity of the purified proteinase in a dose-dependent manner. Several chelating agents, detergents, heavy metals and PQ-8, a currently used commercial antisapstain formulation, also caused a reduction in proteolytic activity in vitro. Selected inhibitory compounds were then tested for their effect on growth of Ophiostoma piceae in artificial media and on wood. Heavy metals and several chelators inhibited growth on media containing protein or inorganic nitrogen, suggesting that they were toxic to the fungus rather than specific to the proteinase. However, chymostatin and PQ-8 did appear to be specific proteinase inhibitors. These products caused a decrease in growth on a protein-supplemented medium which induces proteinase production, but had little effect on growth on medium containing inorganic nitrogen. Visual assessment of lodgepole pine sapwood samples inoculated with Ophiostoma piceae also identified PQ-8 as an effective inhibitor of fungal growth. Other pure chelators and serine proteinase inhibitors did not perform well on wood. While some compounds showed promise in these tests, definitive testing and commercial application are constrained by the current lack of stable, cheap, non-toxic, specific serine proteinase inhibitors.
L D Abraham, D E Bradshaw, A Byrne, P I Morris, C Breuil

Temperature influence on the growing velocity and cellulolytic activities of Poria placenta strains from several locations
1986 - IRG/WP 2263
The differences observed on the FPRL 280 Poria Placenta strain at several Research European Laboratories for determining up the fungicide effectiveness of wood preservative has carry us to do a comparative study about the cellulolytic activity and growth velocity of each of this strains at different temperatures (22, 24 and 28°C). The results show significative differences when the temperature is changed.
A M Navarrete, M T De Troya

Blue-stain fungi (Ceratocystis spp.) found in Spain on pine woods
1989 - IRG/WP 1410
So far, there is only a very limited reported description of the different Ceratocystis spp. present on fresh wood in Spain. So, the main goal of this work has been the identification of species of this genus causing blue-stain on Pinus pinaster A. Ait. and Pinus sylvestris L. woods. We have also investigated the relationship between the species found and their propagation vectors (insects and wind). Finally, we have determined the growing velocity of two of the most representative species found and the presence or absence of degradative enzymatic activities.
M T De Troya, A M Navarrete

Synergistic effects between 2-HPNO, Irganox 1076 and EDTA on the inhibition of wood degradation by Coriolus versicolor
2004 - IRG/WP 04-30331
The efficiency of 2-hydroxypyridine-N-oxide (2-HPNO) as wood preservative has been investigated. As shown using classical experiments as well as using response surface methodology, the efficiency of 2-HPNO as wood preservative is strongly improved in presence a chelator like EDTA and/or of Irganox 1076 an industrial antioxidant. In these conditions, wood preservative efficiency of the mixture the three previous compounds is quite similar to that of tebuconazole used alone. 2-HPNO exhibits an hydroxamic acid function and is a susbtrate of fungal peroxidase. These properties could explain the observed synergy. The implications of these data for the design of new wood preservation strategies are also discussed.
A Mabicka, S Dumarçay, N Rouhier, M Linder, J P Jacquot, P Gérardin, E Gelhaye

Research on the effects of wood preservatives on the physical and mechanical properties of Iranian beech (Fagus orientalis Lipsky)
1985 - IRG/WP 3351
This research work was conducted with the aim of using preservatives such as Basilit and Wolman Salts with Iranian beech and to study any physical and mechanical changes these might have on the beech species of Iran. Samples were divided into three groups; one group were used as untreated controls, the second group was treated with Basilit and the third group was treated with Wolmanit. Results obtained according to the AFNOR French system of standards were: (1) After 140 days the moisture content of each group had reached 7.3%. (2) Samples with Wolmanit absorbed twice as much as those with Basilit and the two groups has some differences in specific gravity. (3) The volumetric shrinkage of wood preserved with Wolmanit was one fifth of that treated with Basilit. (4) In bending tests the samples treated with Wolmanit had more strength up to point of rupture than those preserved with Basilit. (5) The modulus of elasticity was more in samples preserved with Basilit than in those preserved with Wolmanit. (6) In compression parallel to the grain the samples impregnated with Basilit had more resistance than in those impregnated with Wolmanit. (7) In tension tests, the samples preserved with Basilit were stronger than those treated with Wolmanit. (8) In impact bending tests, the Basilit samples were stronger than the the Wolmanit ones. (9) In hardness tests, the resistance to indentation was less with the samples treated with Basilit than with those treated with Wolmanit; the Basilit seems to make the wood softer and from this result this type of treated wood could be recommended for use by carpenters and in woodworking shops.
P Niloufari

Characterisation of growth and stain of different groups of sapstain fungi on lodgepole pine
1999 - IRG/WP 99-10326
Canada is the world&apos;s largest exporter of softwood lumber. These softwood shipments are susceptible to a variety of wood-inhabiting fungi that can lead to sapstain discolouration, which in turn decrease the product value. Furthermore, the presence of these microorganisms may be unacceptable to the importing countries. The objective of this work is to assess the sapstaining capability and basic nutrition of thirty-four fungi isolates representing nine species that were isolated from sawmills across western Canada. The isolates were infected onto fresh lodgepole pine billets and assessed for staining ability, longitudinal growth, host-nutrient consumption, and host viability. The results indicated that the most aggressive saptain species on fresh logs was Ceratocystis coerulescens, followed consecutively by Leptographium spp, Ophiostoma minus, O. piliferum, O. piceae, Ophiostoma spp (D and E) and Aureobasidium pullulans. Preliminary HPLC analysis of soluble sugars indicated that mannose was the free monomer carbohydrate of choice for most of the staining fungi, followed by glucose. Arabinose and galactose were not well utilised. Gas chromatography of infected wood extracts that Leptographium sp. and C. coerulescens significantly reduced the triglyceride fraction.
C Fleet, C Breuil, A Uzunovic, A Byrne

Influence of storage on mould susceptibility of wood at relative humidity values lower than 100%
1989 - IRG/WP 1413
It is well known that wood material changes with time because of different environmental influences. The effects of such changes on the subsequent mould susceptibility are less known. In this paper we report on increased mould susceptibility of pine wood after storage. Mould growth was detected by indirect methods.
J Bjurman

Report on the status of collaborative experiments within the Sub-group on Basidiomycete tests
1983 - IRG/WP 2194
This report summarises the results of co-operative work carried out within the Sub-Group on Basidiomycete tests up to December 1982. The principle findings are recorded in the Conclusions Section. Work intended between IRG-13 in Turkey and IRG-14 in Australia is cited under Future Programme. An Annex provides a response sheet for existing and new participants to notify their contributions.
A F Bravery

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