Your search resulted in 104 documents. Displaying 25 entries per page.
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
Measuring fungal cellulolytic enzyme activity in degrading wood
2011 - IRG/WP 11-10753
An enzyme assay which measures enzyme activity directly from wood will assist in the fundamental understanding of the enzyme components of the decay mechanism of rot fungi and any changes in the presence of wood protectants. At present, to measure fungal carbohydrate degrading enzyme activity in the presence of wood, two methods are used: either 1) the enzyme is measured in the growth media containing lignocellulosic material after the fungus has been allowed to utilize the cellulolytic substrate or 2) the fungus is grown on the lignocellulosic material and the enzymes are extracted using buffers after the growth period and the buffer is analyzed for enzyme activity. This research presents an enzyme assay where wood slivers are added to the assay mixture. The brown rot fungus Postia placenta was grown on wafers measuring 70mm by 23mm by 1.5mm for 12 days. The wafers were then sliced into 3mm by 1mm slivers and assayed using a micro assay using Azo-carbohydrates as substrates. The use of a 96-well microtiter plate allowed a large number of samples to be analyzed at one time with reduced reagent use. Using this assay method allows screening for enzyme activity along the length of the wafer. Our results showed detectable differences over the length of the wafer with a peak of endoglucanase activity closest to the colonization point of P.placenta. Small samples of decayed wood from the field were assayed for endoglucanase activity and the results indicate that this method has a potentially to be used to determine early decay. This assay will be useful in many research fields to gauge the presence and location of fungi and their carbohydrate degrading enzyme activity within a wood sample.
S M Duncan, J S Schilling
Fungicidal activity of some organic solvents, copper carboxylates and their complexes with 2-aminoethanol
1997 - IRG/WP 97-30136
We evaluated the activity of eight organic solvents against wood - rotting fungus Trametes versicolor in order to choose the most appropriate one for rapid screening tests of some copper(II) carboxylates and their adducts with 2-aminoethanol. Their activity against the selected fungus was classified in the following order: chloroform > N,N-dimethylformamide > acetonitrile > methanol > dimethyl sulfoxide > ethanol > acetone. The non-polar white spirit did not dissolve in the growth medium and the results could not be directly compared with the results for other solvents. As an appropriate solvent for screening of the tested copper(II) carboxylates, dimethyl sulfoxide (DMSO) was chosen. Minimal inhibitory concentration against Trametes versicolor of the screened carboxylates was in the concentration range of 1x10-4 to 1x10-3 mol/l. Coordinated amine ligands slightly, and not significantly, decreased fungicidal properties of the tested carboxylates.
M Petric, F Pohleven
Localization of oxalate decarboxylase in the brown-rot fungus Postia placenta
1996 - IRG/WP 96-10161
Oxalate decarboxylase, the enzyme that breaks oxalic acid down into formic acid and carbon dioxide, was recently detected in mycelial extracts of the brown-rot fungus Postia placenta. Differential centrifugation was used to demonstrate that the enzyme is loosely associated with the hyphal surface. Enzyme activity can be removed by washing the hyphae with a low pH buffer. Only low levels of activity were detected in soluble and membrane-bound intracellular fractions. The presence of the enzyme on the hyphal surface and possibly in the hyphal sheath supports the hypothesis that this brown-rot fungus actively regulates the pH and oxalic acid concentration of its environment.
J A Micales
Studies on the biological improvement of permeability in New Zealand grown Douglas fir
1983 - IRG/WP 3231
This report outlines progress towards optimizing conditions for water storage of New Zealand grown Douglas fir with the aim of improving permeability to water-borne preservatives, in particular CCA. Small scale laboratory tests are in progress but the need to scale up to potential commercial applications is being considered. Mixed populations of bacteria isolated from 10 week water sprinkled Douglas fir are being used to inoculate green, sterile timber. Environmental parameters such as pH, temperature and nutrient status are controlled to evaluate optimum conditions of growth, enzyme production and pitmembrane degradation leading to permeability improvement.
K J Archer
Differences in feeding activity among colonies of Formosan subterranean termite Coptotermes formosanus Shiraki
1983 - IRG/WP 1202
Feeding activities of 7 colonies of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were examined. Wood-consumption rates among colonies differed significantly, ranging from 23.80-78.48 mg/g/day. This large intraspecific variation raised a question of whether differences in feeding activity reported for other termite species were due to interspecific differences. When rates were expressed as mg wood consumed by one g termite per day (mg/g/day), termites of larger body weight appeared to consume less wood. This negative correlation, however, was not significant when rates were expressed as mg wood consumed by an individual per day (mg/worker/day).
N-Y Su, J P La Fage
Questionnaire for Volume 2 of the basidiomycete monographs
1985 - IRG/WP 1254
12 monographs of wood destroying basidiomycetes were published in volume 1. Volume 2 includes the following 17 basidiomycetes: Antrodia serialis, Chondrostereum purpureum, Climacocystic borealis, Fomitopsis pinicola, Hyphoderma tenue, Lentinus degener, Lentinus squarrulosus, Paxillus panuoides, Phellinus contiguus, Poria xantha, Pycnoporus sanguineus, Rigidoporus vitreus, Serpula himantoides, Sistotrema brinkmannii, Stereum sanguinolentum, Trametes corrugata
Some tests on ES - AS 11, a novel anti-sapstain formulation, and its properties
1987 - IRG/WP 3399
The results of some tests with the formulation ES - AS 11 are given. The formulation is an attempt to improve the performance of an anti-sapstain chemical by: 1) increasing its penetrability 2) uniquely combining its active ingredients. Very short times of treatment (dipping not longer than 5 seconds), low concentrations of active ingredients, and lower toxicological and environmental risks may be a promising result.
The development of a screening method for the activity of pyrethroids against wood boring marine crustaceans, Limnoria spp
1978 - IRG/WP 443
The present work is concerned with the develepment of a suitable bio-assay technique to determine the biological activity (contact action) of pyrethroids against Limnoria spp. Estimates of the toxicity of three pyrethroids, permethrin, cypermethrin and decamethrin (the structures of which are shown in Fig. 1.) to the marine borer have been obtained.
D Rutherford, R C Reay, M G Ford
Antifungal activity of a stilbene glucoside from the bark of Picea glehnii
2001 - IRG/WP 01-10402
Stilbene glucosides are widely distributed as phenolic extractives in the bark of Picea glehnii, a commercially species planted in the northern area of Japan, and its content reaches to more than 10% by the dried weight of the bark. Although antifungal activities of these compounds have been reported, the mechanism of growth inhibition is still unclear. Isorhapontin (5,4'-dihydroxy-3'-methoxystilbene-3-ß-D-glucoside) is the major constituent of the stilbene glucosides in the bark of P. glehnii. In the present work, the relation between metabolism and antifungal activities of isorhapontin for the white-rot fungus Phanerochaete chrysosporium and the wood staining fungus Trichoderma viride was investigated. Inhibition of fungal growth was obviously depending on the conversion of isorhapontin to the aglycone isorhapontigenin (3'-methoxy-3,5,4'-trihydroxystilbene) by ß-glucosidic activities in the cultures. Exogenous addition of ß-glucosidase also enhances the antifungal activity of isorhapontin. Moreover, less than 100 ppm addition of the stilbene aglycone isorhapontigenin is sufficient to inhibit the growth of both fungi. However, further metabolism of isorhapontigenin was observed after prolonged incubation of the fungi and resulted in detoxification.
S Shibutani, M Samejima
Fungicidal properties of boron containing preservative Borosol 9
2004 - IRG/WP 04-30348
The fungicidal properties of new boron containing wood preservative Borosol 9 is described in this paper. These properties were of particular interest as this new boron containing preservative, exhibit very good performance against wood damaging insects. But because the tested boron formulation contain also nitrogen compounds, we wanted to verify if nitrogen as a nutrient could promote growth of wood rotting and blue stain fungi. Fungicidal activity of the boron based wood preservative Borosol 9 was evaluated according to the standard EN 113 procedure. Samples made of Norway spruce were brushed two times with 10% aqueous solution of Borosol 9, air dried, steam sterilized and exposed to the following wood rotting fungi: Coniophora puteana, Gloeophyllum trabeum and Lentinus lepideus. After 16 weeks of exposure the specimens were isolated and their mass losses were determined. After this respective period, the treated wood samples lost on an average less than 1 % of their initial mass. Parallel to this experiment, blue stain testing according to the EN 152-1 procedure was performed. Specimens brushed with Borosol were for six weeks exposed to blue stain fungi Aureobasidium pullulans and Sclerophoma pithyophila. After testing period the specimens were isolated and anti blue stain efficacy was determined visually. Both tests showed that Borosol 9 has fungicidal properties. Preservative, containing the boric acid - alkanolamine complex did not enhance fungal decay or growth. On the contrary, they showed high activity against wood decay and blue stain fungi.
G Babuder, M Petric, F Cadež, M Humar, F Pohleven
Feasibility of AE (Acoustic Emission) monitoring for the detection of the activities of wood-destroying insects
1992 - IRG/WP 92-2416
The feasibility of acoustic emission (AE) as a nondestructive testing method for the detection of the wood destroying insects was investigated. AEs were detected from the wood specimens under feeding attack of sugi bark borers or powder-post beetles. However, the feasible monitoring area of an AE sensor is influenced by the attenuation of AE amplitude, so that this could be a problem in the practical AE measurements, especially with wood specimens of higher moisture content.
Y Fujii, Y Imamura, E Shibata, M Noguchi
A novel defaunation method of the protozoa to investigate cellulose metabolism in Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)
1994 - IRG/WP 94-10050
The largest protozoa in the hindgut of workers of Formosan subterranean termite, Coptotermes formosanus Shiraki, was selectively eliminated by forced-feeding on low-molecular weight cellulose (LC) with a mean DP of 17. Although one week's feeding on LC caused perfect disappearance of Pseudotrichonympha grassii Koidzumi, the selective defaunation method itself had no detrimental effect on the health conditions of termite on the basis of survival rates and weight changes of workers in the latter feeding. In addition, the fact that the defaunated workers repidly recovered their wood-attacking activity by being mixed with normally faunated workers could well support this assumption. By the results of changes of protozoan fauna when selectively defaunated workers were forced to feed on various cellulose substrates, it was suggested that each protozoan species had its inherent role in cellulose metabolism.
T Yoshimura, K Tsunoda, M Takahashi
Report of activity of CEN/TC 38: Test Methods for Wood Preservatives
1987 - IRG/WP 2287
Effects of terpene compounds on the growth and peroxidase activity of Phellinus pini
1979 - IRG/WP 2130
The volatile compounds myrcene, limonene, a-pinene, a-terpineol, D-fenchol and 1,8-cineole, present in the oleoresin fraction of coniferous wood, were tested individually and as mixtures for their effect on the growth and peroxidase activity of cultures of six strains of Phellinus pini (Fr.) A.Ames and one strain of Phellinus chrysoloma (Fr.) Donk (Phellinus pini var. abietis (Karst.) Pilát). Phellinus pini was more tolerant of the substances than Phellinus chrysoloma. There were differences in the tolerance and peroxidase activity between the strains of Phellinus pini. Peroxidase activity was generally higher in the test cultures than in the controls, but was lower in cultures exposed to 1,8-cineole and a-terpineol.
Physiologic response of Phanerochaete chrysosporium to exposure to triazole fungicides
1994 - IRG/WP 94-10066
Triazoles are increasingly important fungicides which are employed for a variety of applications included wood protection. Several recent studies suggest that white rot fungi are more tolerant of triazole compounds than other wood degrading fungi. Cultural studies using a white rot fungus, Phanerochaete chrysosporium, and 0.2 or 0.8 ppm of tebuconazole or propiconazole suggested that mycelial dry weight was most affected by the presence of triazoles. Extracellular carboxymethylcellulase, cellobiosidase and phenol oxidase activities were depressed but not inhibited by triazoles, while ß-glucosidase activity appeared to be slimulated by the presence of these biocides. The results suggest that white rot fungi may be less sensitive to triazoles and this diminished sensitivity may permit these fungi to become more important on wood treated with this biocide.
J J Morrell, R K Velicheti
Effects of Trichoderma harzianum on enzyme activity and oxalic acid production of Gloeophyllum trabeum in ponderosa pine sapwood blocks
1992 - IRG/WP 92-1550
The effect of a bioprotectant, Trichoderma harzianum, on the activity of Gloeophyllum trabeum was investigated using a wood wafer sandwich method. Wood weight loss was greatest with Gloeophyllum trabeum exposed wafers, intermediate with those exposed to both the bioprotectant and decay fungus, and lowest with the bioprotectant exposed wafers. Extracts of wood wafers after 2, 4, or 6 weeks of fungal exposure revealed that the bioprotectant depressed, but did not completely inhibit enzyme activity of the decay fungus. Analysis of extracts for oxalate content revealed that the bioprotectant had little effect on the levels of oxalate present. The results suggest that the bioprotectant was not capable of completely inhibiting the decay fungus. Further trials to evaluate the effect of prior bioprotectant colonization on basidiomycete activity are planned.
C M Sexton, J J Morrell
Wood decay of Pinus sylvestris L. by marine fungi
1990 - IRG/WP 1463
Waterlogged wood decay by marine microorganisms represents a major problem for the conservation of wood structures of historic value. It is important to know which kind of decay affects the wood from a conservation point of view. Enzyme activities of 14 marine fungi belonging to several localities were studied. Also, the weight loss and the rot type suffered by the wood at a microscopic level were studied, in comparison with 3 standard rot-producing fungi (white rot, brown rot and soft rot).
M C Escorial, M T De Troya, J E Garcia de los Rios
Assessment of dehydrogenase activity, fluoride content and total chromium content of soil profiles exposed to preservative treated wood within a model system
1993 - IRG/WP 93-10015
The development and prospective use of a closed model system to facilitate study of a number of indicators of environmental impact of wood preservatives laboratory conditions has been described (IRG/WP/2395-92). Chemical analysis of leachate samples collected from drained soil profiles containing creosoted pole sections remedially treated with a chromated fluoride preservative indicated small increases in fluoride and chromium concentrations. This paper details measurement of dehydrogenase activity and chemical analysis of soil samples recovered from the surface layers of the model soil profiles adjacent to treated pole sections. Reduced levels of dehydrogenase activity were associated with increased soil concentrations of leached preservative components and lower organic matter content. Findings are discussed as part of an assessment of environmental impact of the remedial treatment in the field
G M Smith, D C R Sinclair, A Bruce, H J Staines
A Long-term Observation of Termite Activity in The Nest by Continuous Acoustic Emission (AE) Monitoring
2003 - IRG/WP 03-20280
In order to evaluate the influence of temperature on the termite activity, acoustic emission (AE) monitoring was applied to two nests of Coptotermes formosanus SHIRAKI; a nest in the stem of a standing tree and a nest in the underground of a wooden house, respectively. Temperature change in and around the nests were continuously measured for about one year using thermocouples at four points; the centre of the nest, the periphery of the nest, the environment around the nest, and the underground, respectively. AEs were detected at the centre of nest and underneath the nest sphere by using wave-guides inserted into the nest of the standing tree and at the centre of nest. AEs were also detected at the wooden construction member near the nest in the wooden house. The termites in the nests were periodically stimulated by rotating, drawing and sticking the wave-guides. The temperatures in the both nests varied from 5 to 35 °C during the experiment. The highest and the lowest temperatures were recorded in August and February, respectively. The highest AEs event rate was recorded when the temperature of the nest in the tree was between 30 and 35 °C and when the temperature of the nest under the house was above 25 °C. In winter, when the nest temperature was below 10 °C, no significant numbers of AE were detected. These findings clearly show that AE generation has a close relation to the termite activities, which are influenced by the temperature in the nest.
Y Yanase, Y Fujii, S Okumura, T Yoshimura, Y Imamura
Enzyme systems of bacterial isolates from ponded logs - Potentials of pectin and/or starch degradation
2000 - IRG/WP 00-10378
This paper deals with the degradation potentials of wood constituents by the bacterial isolates from ponded logs. The potentials to degrade pectin as a constituent of pit-tori as well as starch existing in ray parenchyma cells in the areas of sap- and transition wood with the isolates were examined. The pectinase activity was investigated by means of the degradation degree of a carrot strip used as a single carbon source in a liquid medium. The amylase activity was studied by the colour change on the iodostarch reaction in an agar medium containing soluble starch as a single carbon source. The results suggested that these substrates were degraded sequentially by plural bacterial species that invaded in the logs during ponding.
S Doi, S Ohta
Some data on the activity of alternative fungicides for wood preservation
1985 - IRG/WP 3333
Data from laboratory tests against basidiomycete fungi are presented for 9 alternative fungicides in organic solvent formulations and also in water for one product. Results are compared with data for reference preservatives, tributyltin oxide, copper and zinc naphthenates and pentachlorophenol. Of special interest is the apparently better than additive effect of mixing tributyltin naphthenate and Xyligen B, and the promising performance of Armoblen 480, a novel organic solvent formulation of n-alkyl coco-derived quaternary ammonium compounds.
A F Bravery, J K Carey
A comparison of inductively coupled plasma spectroscopy and neutron activity analysis for the determination of concentrations in wood
1993 - IRG/WP 93-10048
As wood decays the ionic composition changes, with increases often being seen in the concentrations of Ca, Mg, Fe, Mn and sometimes K. The concentration of eight cations in red spruce sapwood and heartwood samples was determined independently by inductively coupled plasma spectroscopy (ICP) and by neutron activation analysis (NAA) as part of an effort to standardize our analytical procedures and create a uniform wood standard for use by multiple researchers. Preliminary studies indicate a difference in the values of Ca and K as estimated by ICP and NAA, possibly due to a loss of these elements due to volatilization during ashing.
J Jellison, J Connolly, K C Smith, W T Shortle
ATP assay for the determination of mould activity on wood at different moisture conditions
1992 - IRG/WP 92-2397
To determine fungal responses to fungicides and environmental conditions and for detection of microbial activity in wood, sensitive and objective methods are needed. We have developed a suitable assay based on analysis of adenosine triphosphate (ATP) by using the luciferin-luciferase reaction. With the aid of this assay the activity of Penicillium brevicompactum on wood at different RH levels was studied. The ATP content in a two week old culture responded quite rapidly to changes in humidity. The ATP content in the colony moved to 70% or lower RH for one week was 10 times lower than the ATP content in the colony kept at 100% relative humidity for the same time period. Increasing the humidity level to 100% RH one week before the ATP determination from a period at lower humidities did not result in a significant increase in the ATP content. This probably indicates that the mycelia of the fungus did not survive the low humidity treatment.
Fungicidal activity of some new water borne copper octanoate based formulations
1999 - IRG/WP 99-30198
Four new water borne formulations for preservation of wood were prepared: the composition of Cu(II) octanoate, 2-aminoethanol (ethanolamine) and water; the composition of complex of Cu(II) octanoate with nicotinamide, 2-aminoethanol and water; the one of Cu(II) octanoate, organic boron complex, 2-aminoethanol, dimethyl sulfoxide and water and finally, the mixture of Cu(II) octanoate, diazene, 2-aminoethanol and water. Fungicidal activity of these new formulations against Trametes versicolor, Antrodia vaillantii and Coniophora puteana was determined by filter paper and mini-block test methods. Compared to the commercially used wood preservative containing Cu(II) naphthenate / Cu(II) 2-ethylhexanoate, the new compositions have stronger fungicidal activity. The strongest biocidal activity was exhibited by the formulation with a Cu(II) octanoate/nicotinamide complex.
M Petric, M Pavlic, F Pohleven, P Segedin, B Kozlevcar, S Polanc, B Stefane, R Lenarsic