Your search resulted in 229 documents. Displaying 25 entries per page.
Effect of Volatiles from Trichoderma species on the regulation of protein synthesis in Serpula lacrymans isolates
2002 - IRG/WP 02-10440
The growth of wood decay fungi has previously been shown to be inhibited by volatile organic compounds (VOCs) from selected Trichoderma isolates. No mechanism of action has however been established for such inhibition. This paper reports the effects of VOCs produced by Trichoderma pseudokoningii, T. viride and T. aureoviride on the growth of four dry rot isolates and corresponding protein synthesis in two of these Serpula lacrymans strains. Volatile inhibition of growth was measured using a simple plate bioassay with S.lacrymans mycelium subsequently extracted and protein profiles analysed by SDS-PAGE. Two S.lacrymans strains isolated from building timbers were generally more sensitive to the Trichoderma VOCs compared with a strain isolated from the Himilayas or a standard lab culture strain. VOCs from T. aureoviride and T. viride affected protein synthesis in both target S. lacrymans strains, but those from T. pseudokoningii.had no effect. These results mirrored the patterns of growth inhibition in the target fungi with VOCs from T.pseudokoningii having little effect on growth of the dry rot fungi. Interestingly, when the antagonists were removed growth of the S. lacrymans isolates resumed and the original protein patterns were restored. This suggests that the VOCs act on the basic expression of proteins by the S. lacrymans rather than interfering with protein function after synthesis.
S Humphris, R Wheatley, E Buultjens, A Bruce
A new approach to wood protection: Potential of biologically synthesised CuO and ZnO nanoparticle formulation as a wood preservative
2022 - IRG/WP 22-30758
Even though metal nanoparticles are effective in protecting wood, they are less preferred, as they are synthesised using methods which are expensive and are not environmentally friendly. Biological synthesis of nanoparticles using plants, fungi, yeast, bacteria and viruses, has been accepted as an alternative approach and is referred to as green synthesis. Utilization of biologically synthesised nanoparticles is a new approach in wood protection. In the present study, copper oxide and zinc oxide nanoparticles were synthesised using leaf extracts of, Azadirachta indica A. Juss, Pongamia pinnata L Pierre, Lantana camara L, Chromolaena odorata L. R.M. King & H. Rob, Ocimum sanctum, Parthenium hysterophorus L and Nerium oleander L respectively. The formulation of leaf extracts and the synthesised nanoparticles were tested for their efficacy as a wood preservative as per BIS standards against termites, wood decay fungi (Trametes hirsuta Wulf. ex Fr., White-rot and Oligoporus placenta (Fr.) Gilb. and Ryvarden, brown-rot) and wood borer (Lyctus africanus Lesne). After one year of field evaluation, it was observed that control stakes were destroyed completely as an indication of active termite infestation. Formulation of P. hysterophorus leaf extract and CuO nanoparticles protected the treated rubberwood specimens from termite attack for a period of three months and CuO-P. pinnata for six months. Whereas formulations of L. camara, N. oleander and A. indica leaf extract with CuO nanoparticles protected the treated rubber wood specimens for a period of seven months. C. odorata leaf extract and CuO nanoparticle formulation gave complete protection to the treated rubberwood specimens for a period of 12 months. Results of the laboratory assay indicated that, when compared to control blocks, the formulation of L. camara leaf extract and CuO nanoparticles effectively protected the treated rubberwood from the attack of both white-rot and brown-rot, whereas the formulation of N. oleander leaf extract, CuO and ZnO nanoparticles protected brown-rot attack only. Formulation of leaf extracts of A. indica and L. camara with CuO nanoparticle were found to be effective against the Lyctus africanus Lesne for a period of two years. Leaching studies were conducted as per AWPA and the ability of chitosan to prevent leaching and its effect on efficacy was also evaluated. It was observed that dip treatment with chitosan (5%) significantly prevented the leaching of copper ions from the treated rubberwood specimens. Further studies are required to assess the stability, shelf life and toxicity of the formulation in order to recommend it as a commercially viable wood preservative.
Shiny K S, R Sundararaj, N Mamatha
Biological screening assays of wood samples treated with creosote plus chemical additives exposed to Limnoria tripunctata
1980 - IRG/WP 408
Laboratory methods for exposure of treated wood coupons to Limnoria tripunctata are described. Chemical additions to creosote were screened using this method. Three pesticides, Endrin, Kepone, and Malathion proved particularly effective. The addition of varying percentages of naphthalene to creosote using several treatment methods are currently being assayed. Results to date show that the coupons treated by the empty cell method have better performance than those prepared by the toluene dilution method. The naphthalene coupons treated by the full cell method show no attack after six months' exposure.
B R Richards, D A Webb
Penichroa fasciata (Stephens) (Col. Cerambycidae) a pest in wood materials
1988 - IRG/WP 1365
Penichroa fasciata (Stephens) (Col. Cerambycidae) is found to be a frequent pest occurring in hardwood in storage in Italy. This paper reports the characteristic for identification, biological features, distribution and timber liable to attack.
A Gambetta, E Orlandi.
Biological control with Trichoderma harzianum in relation to the formation for spores the production of soluble metabolites
1994 - IRG/WP 94-10073
The amount of spores produced by three strains of Trichoderma harzianum on the aerial mycelium of agar cultures and in shake cultures, respectively, correlated with the inhibition zones exerted against Phanerochaete chrysosporium in an agar diffusion test. The amount of soluble antifungal metabolites as well as the protein content also correlated with the inhibition zones and the amount of spores produced. The antifungal metabolites were identified to be trichorzianines. They were the only compounds with antifungal activity. It is concluded that the trichorzianines are responsible for the biocontrol effect by soluble metabolites and that they are produced during conidiogenesis.
J Bürgel, E Horvath, J Haschka, K Messner
Chemical compounds from Eperua falcata and Eperua grandiflora heartwood and their biological activities against wood destroying fungus (Coriolus versicolor)
2005 - IRG/WP 05-30373
The chemistry analysis of the compounds present in dichloromethane and ethanolic fraction as well as bioassays enables to understand the durability differences of Eperua falcata and Eperua grandiflora. The principal distinction between these two species is the acidic subfraction of diterpenoic extract, which is antifungic in Eperua falcata when tested in in-vitro conditions. This study also enables to show that ethanolic fraction plays an important role in the mechanism of natural durability. It also reports the first isolation of cativic acid in Eperua falcata wood.
N Amusant, C Moretti, B Richard, E Prost, J M Nuzillard, M-F Thévenon
Physical and biological properties of albizzia waferboards modified with cross-linking agents
1995 - IRG/WP 95-40043
Chemically-modified low-density waferboards with cross-linking agents were produced using a fast-growing species of hardwood albizzia (Paraserienthes falcata Becker) as a raw materials and isocyanate resin as a glue adhesive. For the chemical modification, the vapor-phase formalization of the boards and the pad-dry-cure treatment of wafers with cross-linking agents were employed. The vapor-phase formalization was conducted for 5, 10 and 24 hours using tetraoxane as a source of formaldehyde, and the pad-dry-cure treatments with glutaraldehyde and ethyleneurea compound (DMDHEU) were made after impregnation of their 5 and 10% aqueous solutions of each chemical. Sulfur dioxide was used as a catalyst in both treatments. About 70% of antiswelling efficiency (ASE) was gained in all treated boards irrespective of reaction time or solution concentration. All treated boards were very stable to water soaking even in the 2-hour boiling on thickness swelling as well as linear expansion. Laboratory tests with brown-rot and white-rot fungi revealed that decay was completely suppressed in formaldehyde-treated boards, and small losses in weight were counted in other treated boards. All treated boards were also effective in resisting to the attack by the destructive termite Coptotermes formosanus.
S Yusuf, Y Imamura, M Takahashi, K Minato
Biological control of the Formosan subterranean termite Coptotermes formosanus Shiraki
1971 - IRG/WP 100
M Tamashiro, J K Fujii, P Lai, T E Richardson
Working Group I 'Biological Problems' Sub-group 'Insects in dry wood (other than termites)', Scope of work
1976 - IRG/WP 152
Antagonistic effects of a range of fungi to Serpula lacrymans
1996 - IRG/WP 96-10156
Certain fungi have been demonstrated to exhibit antagonism towards Serpula lacrymans in culture. Species from the genera Trichoderma, Gliocladium, Penicillium and Hypomyces were among those exhibiting the strongest antagonism. Certain species showed antagonism in a range of media of varying nutritional status. The possible role of antagonistic fungi as biocontrol agents for Serpula lacrymans is discussed.
P Rattray, G McGill, D D Clarke
Possibility of use of wood species per class of biological risks. Attempt to determine criteria based on Pr EN 350-1/2/3
1992 - IRG/WP 92-2409
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
Effects of a chitin synthesis inhibitor on spore germination of the decay fungi Gloeophyllum trabeum and Poria tenuis
1986 - IRG/WP 2253
This study sought to determine the effect of a chitin synthesis inhibitor - Polyoxin D, on spore germination and early hyphal development of a brown rot and a white rot fungus in-vitro. Polyoxin D is a competitive, substrate-analogue type of chitin synthtase inhibitor (2). The drawbacks to use of such a compound as a wood preservative tie. cost - $20,000/g, possible leaching or degradation) might be reduced should it be effective in preventing decay initiation by spore germination at very low concentrations.
E L Schmidt
Biological Durability of Laminated Veneer Lumber from Durable and Non-Durable Wood Species
2005 - IRG/WP 05-10567
Laminated Veneer Lumber (LVL) was laboratory manufactured using veneers from decay and non decay resistant species in order to evaluate changes in the durability as a result of the LVL manufacturing process, and to test if the mixing of decay resistant species and non decay resistant species can improve durability. Laboratory soil block test and field test were conducted. The durability of solid wood was comparable to that of LVL made using the same species. For LVL made using veneer from durable and non-durable wood species, durability was improved when two faces and one core veneers were from decay resistant species.
P Nzokou, J Zyskowski, S Boury, D P Kamdem
Biological performance of gypsum products containing borates
2000 - IRG/WP 00-30237
At suitable retentions borates have biostatic properties enabling them to be used for biodeterioration control in wood. They provide protection against decay fungi, mould, and termites, which are known to also attack gypsum products. Currently, many gypsum products contain added borates, which are used to improve physical and processing characteristics. Work examining the effect of borates at controlling biological attack in gypsum products is presented in this paper. Gypsum or gypsum board with different borate loadings was tested for its performance against dry rot, mould, and subterranean termites in order to see if current commercial levels of borates used in gypsum products would also render them resistant to these common types of biodeterioration. It was confirmed that the presence of borates significantly decreases the amount of biological attack found in gypsum products. From the results obtained it can be concluded that the addition of borates to gypsum products provides more than simple mechanical and processing improvements. For complete biodeterioration control however, especially against mould, higher retentions should be considered. This knowledge could have great significance in the near future, with moves to require termite resistant construction materials (including gypsum board) in some areas and the rising concern of illnesses associated with 'sick building syndrome' caused by in-house mould growth.
J L Fogel, J D Lloyd
Biological control of Serpula lacrymans using Trichoderma spp
1994 - IRG/WP 94-10069
The effectiveness, or otherwise, in killing Serpula lacrymans, of a range of Trichoderma spp. in a variety of media and using two different incubation systems has been tested. In agar based systems with normal nutrients or minimal nutrients with high or low nitrogen contents and high or low iron content Trichoderma harzianum 25 proved to be the most efficient and killing Serpula lacrymans. Other species, such as Trichoderma hamatum 150, were effective in some media but not in others. Initial observation on partially decayed small wood blocks suggested that actively growing Serpula lacrymans could not be killed by Trichoderma spp.. Experiments undertaken on a specially designed system, however, indicated that certain Trichoderma spp. can act as effective antagonists even in wood based systems.
A J Score, J W Palfreyman
European standardization for wood preservation
1990 - IRG/WP 2359
Biological control of decay in standing creosote-treated poles
1976 - IRG/WP 156
Internal decay caused by basidiomycetes in standing creosoted poles can be controlled biologically, it seems, by artificial inoculation near the ground line. For such inoculation IC-type facultative mycoparasites, Scytalidium sp FY strain or Trichoderma spp for example, may be used. Apparent residual action can be explained by the release of non water soluble chemically stable antibiotics from the growing hyphae of the artificially planted micro-organism.
Biological agents of timber degradation in Portugal. Marine borers
1991 - IRG/WP 4171
A brief report of the studies carried out in Portugal on marine borers is presented. The marine borers found in the portuguese coast are refered as well as the wood species where those organisms were identified. Emphasis is given to a study carried out from 1960 to 1975 at the Tagus estuary in Lisbon with the purpose, among others, of establishing the natural durability of different timbers.
J S Machado, L Nunes
How best to specify retentions of preservative treatments: kg/m3 or % (m/m)
1998 - IRG/WP 98-20151
When specifying treatments according to the European Standard EN 351-1, retentions in the analytical zone are based on the amount of product found to be effective in biological tests; this is expressed in terms of the retention of the product per unit volume (kg/m3) for penetrating treatments and per unit area (g/m2) for superficial treatments. However, to check whether the retentions have been achieved, chemical analyses are carried out where the results are initially expressed as% (m/m). In converting results from% (m/m) to kg/m3 , a value for the density of the wood must be applied that is closely associated with the sample of wood taken for chemical analysis. This is difficult to achieve and it has been suggested that the results from biological tests and the associated retention values be expressed in% (m/m) to avoid this difficulty. For treatments applied by penetrating treatment processes, expression of the retention of a wood preservative product as% (m/m) reduces error. The initial dry weight of the test specimens affects the relationship between retentions expressed as kg/m3 and% (m/m) because heavier test specimens take up less treating solution. The change in the method of expressing the retention of a wood preservative product to% (m/m) is unlikely to have any major effect on the results within a wood species. However, the change reduces the difference between the retentions which are effective in Scots pine sapwood and beech against attack by Coriolus versicolor. Use of% (m/m) instead of g/m2 offers no advantages for superficial treatment processes.
J K Carey
About the water and biological resistance of some new chemically modified wood composites
1997 - IRG/WP 97-40077
As well known, wood represents a valuable natural composite material with a very large utilisation as solid wood or in wood based composite materials. Its qualities but also its defects as the dimensional instability, the susceptibility to biological attack, the anisotropy, are due to its complex structure. Research has demonstrated that the chemical modification of wood, meaning the involving of its main chemical components through their reactive alcoholic hydroxyl groups in chemical reactions with different chemical reagents, can be a new way to ameliorate the wood or wood composites but also to obtain new wood based materials. The chemical thermoplasticization of wood, studied theoretically and experimentally by the Japanese researchers as Matsuda, Mori, Morita, Nakano, Shiraishi, Ueda seems to be a very interesting possibility. The paper presents the results of our experiments concerning the chemical thermoplasticization of wood through oligoesterification and the obtaining and characterisation of some products based on this type of chemically modified wood. In fact the main goals of this stage of the researches were: - the obtaining and characterisation of the thermoplastic wood; - the study of the thermoformation possibilities for the thermally flowable material obtained as sawdust; - the evaluation of the possibilities to carry out this chemical modification process as a surface treatment for solid wood; - the evaluation of the water and biological resistance for the obtained products.
M C Timar, M D Mihai, G Baciu
The leachability, biological resistance, and mechanical properties of wood (Pinus sylvestris L.) treated with CCA and CCB preservatives
1999 - IRG/WP 99-30207
Scots pine (Pinus sylvestris L.) specimens treated with CCA and CCB preservative solutions (1.0%) were subjected to several fixation processes and leached elements from the specimens were determined. In addition, the specimens exposed to different fixation temperatures were subjected to soil-block test using two brown-rot fungi and one white-rot fungus in order to investigate the effects of fixation temperature on the biological performance of treated wood. The effects of preservative treatment and subsequent redrying at temperatures of 20°C and 70°C on the bending strength, MOE (modulus of elasticity), and impact bending strength of small, clear specimens treated with CCA. At 20°C and high moisture contents and also with steaming, leaching rate of the components decreased. In addition, the specimens treated with CCB and conditioned at 20°C/32-100% RH (relative humidity) conditions, the percent elements leached were less than those in the specimens treated with CCA and also the rate of fixation increased significantly in the CCB-treated specimens. In the CCA treatments, the weight losses by Gloeophyllum trabeum and Postia placenta fungi were more than 5% with the fixation methods such as ovendrying at 120°C, and steaming at 80°C for 60 and 90 minutes while with the other fixation methods, the weight losses obtained were less than 5%. At redrying temperatures of 20 and 70°C, CCA had no significant negative effect on the bending strength, MOE, and impact bending strength properties of the specimens.
S N Kartal
Some biological observations on the management of preservativion experiments with submerged timber in the marine environment
1976 - IRG/WP 421 E
Antagonistic effect of some mycorrhiza fungi as biological control of blue-stain
1987 - IRG/WP 1314
This report discussed the possibility of using some mycorrhiza fungi as biological control of blue-stain. The results show that new bio-technological possibilities are opening, because, by cultivating antibiosis fungi in fermentor, it is possible to prepare extracts which can then be used as the natural preservative to control the blue-stain in wood.
Biological and chemical observation on the early fungal colonization of TBTO treated Swedish redwood stakes
1984 - IRG/WP 3311
Data on the early fungal colonization of Swedish redwood stakes, impregnated with 1% TBT0 / 0.5% dieldrin solution, both by double vacuum impregnation and immersion processes are presented. Results of chemical analyses of wood samples from the outer 1 mm of separate painted and unpainted stakes, exposed over the same twelve month period, are also discussed.
R Hill, A H Chapman, A Samuel, K Manners, G Morton