Your search resulted in 220 documents. Displaying 25 entries per page.
The involvement of extracellular substances for the generation of hydroxyl radical during wood degradation by white-rot fungi
1997 - IRG/WP 97-10218
The activities of one-electron oxidation, hydroxyl radical generation, and phenol oxidase during the incubation of cultures of four white-rot fungi containing either glucose or wood were periodically measured. Further, their degradation activities against wood were examined during the course of cultivation. The generation of hydroxyl radical was correlated to the activity of wood degradation and i...
H Tanaka, S Itakura, A Enoki
Micromorphology of oak wood degraded by brown rot fungus Coniophora puteana
2000 - IRG/WP 00-10356
To characterize the degradation of hardwood by brown rot fungus, Coniophora puteana was incubated on the wood blocks of Quercus accutissima. For comparison, the same fungus was also incubated on the pine wood blocks of Pinus densiflora. In softwood, the shape of the wood cells and thickness of the cell appeared unchanged even the loss of birefringence in the affected areas. In contrast, oak wood d...
Yoon Soo Kim, Seung-Gon Wi, Kwang-Ho Lee
Kinetics of the dissociation of Cr, Cu, and As in fixed CCA-treated wood
2001 - IRG/WP 01-50168
The results of an experiment showing the kinetics of the dissociation of CCA compo-nents in water within treated wood samples are presented. Dry red pine (Pinus resinosa Ait.) samples were simultaneously vacuum-treated with water, then expressed to re-move the water at successive time intervals. The expressate was then analyzed for Cr, Cu, and As concentration by inductively coupled plasma (ICP). ...
L Waldron, P A Cooper
Persistence and residual activity of organophosphorus termiticides in soil and prevention against the degradation of chlorpyrifos
1991 - IRG/WP 1518
The persistence and the residual activity of four comercial organophosphorous termiticides, Chlorpyrifos, Fenitrothion, Tetrachlorvinphos, Pyridaphenthion, in soil were studied under laboratory conditions. The persistence and the residual activity of four organophosphorous termiticides in two types of soil decreased with the lapse of time. These termiticides were mostly degraded by microorganisms ...
T Iijima, M Tanaka, M Higaki
Biological degradation resistance of wood acetylated with thioacetic acid
1983 - IRG/WP 3223
Chemically, modification of wood is being considered as an alternative to conventional preservation by toxic chemicals. Acetylated wood has been reported to be quite resistant to most biodegrading organisms at weight percent gains (WPG) around 15-19. The conventional acetylation techniques with acethic anhyrdride result in generation of acetic acid. However, acetylation with thioacetic acid overco...
S Kumar, S C Agarwal
Chemical and biological investigations of double-vacuum treated windows after 7½ years in service
1985 - IRG/WP 3339
Earlier investigations of double-vacuum treated windows after five years in service have shown that tributyltin oxide (TBTO) degrades to di- and monobutyltin compounds and that the resistance of the wood against decay decreases. An investigation 2.5 years later of the same windows shows that the degradation of TBTO proceeds fast. After 7.5 years in service only 15-35% of the remaining organotin co...
M-L Edlund, J Jermer, B Henningsson, W Hintze
Screening of fungal strains for wood extractive degradation
1998 - IRG/WP 98-10254
Fungal strains were screened for their ability to degrade apolar extractives in wood from scots pine. The degradation of total wood extractives by 91 different strains was monitored in stationary batch assays incubated for 6 weeks. The results obtained show that the ability of wood-inhabiting fungi to utilize wood extractives varied greatly, even for different isolates of the same species. Fungal ...
J Dorado, M J Martinez-Inigo, T A van Beek, F W Claassen, J B P A Wijnberg, R Sierra-Alvarez
Microscopic FT-IR depth profiling study of photo-induced degradation in wood
2001 - IRG/WP 01-20229
FT-IR microspectroscopy was used to monitor the changes in the chemical composition at various depths from the photo-irradiated surface of sugi (Cryptomeria japonica D. Don) sapwood. The radially cut wood face was exposed to artificial solar radiation from a xenon light source at 375 Wm-2 (in a 300 - 700 nm spectral range) for up to 600 h. The IR depth profiling spectra showed that the artificial ...
Y Kataoka, M Kiguchi.
Bacterial degradation of wood cell wall: A review of degradation patterns
1990 - IRG/WP 1460
Information from bacterial degradation studies of 60's and 70's was reviewed by Nilsson in 1982. The application of electron microscopy to this area in recent years has provided much useful information and has eliminated earlier scepticism among workers about the ability of bacteria to degrade lignified wood cell walls. Studies using transmission electron microscopy together with...
A P Singh, J A Butcher
The degradation of wood surfaces by dilute acids
1985 - IRG/WP 3326
Thin radial/longitudinal sections(~100 µ) of Corsican Pine (Pinus nigra) and Lime (Tilia vulgaris), were exposed to Sulphuric, Sulphurous, nitric, acetic, and formic acid at 40°C in the pH range 2-6. After about 3 months exposure to Sulphuric, nitric, acetic and formic acid at pH 2.0 Pine lost some 20-25% of its tensile strength. Losses in tensile strength due to sulphurous acid were greater bei...
P D Evans, W B Banks
Degradation of resin constituents in various wood species by the white rot fungus Bjerkandera sp. strain BOS55
1999 - IRG/WP 99-10301
In previous studies, the white-rot fungus Bjerkandera sp. strain BOS55 was shown to cause extensive degradation of lipophilic extractives (resin) in Scots pine wood. Further research was carried out in order to investigate the ability of Bjerkandera sp. for reducing resinous constituents in various softwood (Douglas fir, larch and spruce) and hardwood species (birch, beech and poplar). The greates...
J Dorado, T A Van Beek, F W Claassen, R Sierra-Alvarez
Effect of fungal degradation on the chemical composition of acetylated beech wood
2003 - IRG/WP 03-40267
This study investigated the impact of fungal attack on the chemical composition of acetylated wood. Beech wood acetylated to different degrees was exposed to decay by the white-rot fungus Trametes versicolor under solid-state fermentation conditions. Laboratory soil-bed assays were also conducted to study the degradation of acetylated wood by soft rot fungi and other soil-inhabiting microorganisms...
H Militz, Dong-won Son, L Gómez-Hernández, R Sierra-Alvarez
Influence of the content of organic matter of soil on the degradation of wood by soft rot fungi
1970 - IRG/WP 27
The degradation of wood specimen burried in the soil by soft rot fungi is influenced by a number of factors. These are in particular the water holding capacity, water content, content of organic matter, pH, content of mineral nutritive substances etc. The results of the interlaboratory tests, carried out within the IRG/WP let presume that the intensity of wood degradation occurs proportionally inv...
O Wälchli
Degradation of woods by obligately anaerobic fungi
1990 - IRG/WP 1452
Little is known about the processes occurring during the degradation of wood by obligately anaerobic fungi. When woods from a range of hardwood species were incubated for 11 days with a strain of the Chytrid Neocallimastix frontalis many of the woods were measurably fermented; Fagus sylvatica (23%) was the most highly degraded. Microscopic examination of Populus tremuloides wood after incubation w...
K N Joblin, G E Naylor
Determination of thermal degradation of isothiazolone treated wood
1997 - IRG/WP 97-30154
Wood treated with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one was the subject of thermal degradation study. The study included burning isothiazolone treated wood under various temperatures with and without oxygen. The result showed that no harmful combustion products, such as polychlorinated dibenzo-p-dioxins, polychlorinated dibenzo-p-furans and polychlorinated biphenyls, were detected. These fin...
Bing Yu
Analysis of the degradation of carbohydrates by blue-stain fungi
1990 - IRG/WP 1457
The topic of the degradative ability of blue-stain fungi literature is not clear. Many authors support the idea that those fungi don't have enzymatic capability to decay the wall of the ligneous cells. However, others have found some decay activity. In this study, we have attempted to analyze which wall cells soluble carbohydrates are metabolized by some blue-stain fungi, found in Spain. ...
M T De Troya, A M Navarrete, E Relano
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 4: Conversion reactions during storage
1974 - IRG/WP 332
Precipitates simulating those produced in wood by preservative fixation reactions were prepared by the reduction of Boliden K 33 and Celcure AP solutions with hydrogen peroxide and hydrazine. The pH changes on aging at 20 and 50°C were studied and related to the chemistry of fixation previously described. Hydrolysis of copper arsenates may render arsenic acid temporarily water soluble pending pre...
S-E Dahlgren
Extracellular laccase production in brown-rot fungus Coniophora puteana
2001 - IRG/WP 01-10391
Coniophora puteana, one of representing brown-rot fungus, was investigated in terms of extracellular ligninolytic enzyme production. Three fungal strains of C. puteana were inoculated in liquid culture medium with sawdust of pine and oak wood. Extracellular laccase production was observed in some strains of C. puteana in the culture medium with sawdust of oak wood. The highest activity occurred at...
Kwang-Ho Lee, Seung-Gon Wi, Yoon Soo Kim
Immunolabelling studies on the detection of enzymes during the degradation of wood by Phanerochaete chrysosporium
1988 - IRG/WP 1364
The degradation of lignin in native lignocellulosic substrates by white rot fungi is poorly understood. Biochemical studies have shown the involvement of a number extracellular ligninolytic enzymes released by white rot fungi which are capable of the oxidative conversion of DHP's (lignin model compounds) in vitro, but to date conclusive evidence for occurrence of these enzymes in wood und...
G F Daniel, T Nilsson, B Pettersson
Fungal degradation of wood treated with metal-based preservatives. Part 1: Fungal tolerance
1996 - IRG/WP 96-10163
In recent years, concerns have arisen about the leaching of heavy metals from wood treated with chromated copper arsenate (CCA), particularly because of the large amount of CCA treated wood that will be discarded in the coming years. The long term objectives of this work are to determine the fate of copper, chromium and arsenic with the aging and potential decay of CCA-treated wood, and to develop...
B Illman, T L Highley
Inhibition of the biodegradation of coniferous and broadleaved wood by new imidazolium salts
2003 - IRG/WP 03-30320
Studies were carried out on fungicidal values of fourteen potential wood preservatives – modified quaternary heteroaromatic compounds using the screening agar-block. The vacuum treated blocks (22mm x 17mm x 12mm) of Scots pine (Pinus sylvestris L.), spruce (Picea excelsa L.), beech (Fagus silvatica L.) and birch (Betula verrucosa Ehrh.) with testing compounds were exposed to Coniophota puteana a...
J Zabielska-Matejuk, J Pernak, W Wieczorek
Biological variability in the oxalate/oxalate decarboxylase system among five isolates of the wood-degrading fungus Meruliporia incrassate
2006 - IRG/WP 06-10573
The “dry-rot” wood decay fungus Meruliporia incrassata has recently attracted attention, primarily in the western coastal United States, as a particularly destructive pest of building material. Recently, the US Environmental Protection Agency (EPA) has accepted a voluntary withdrawal of the historically effective chromated-copper arsenate (CCA) as a preservative for wood used in residential se...
C Howell, J Jellison
Fun with Soil Block Jars: Teaching fungal wood decay in the classroom
2006 - IRG/WP 06-10574
In this world of increasing complexity and technological advancements, it is ever more important to raise scientifically literate children. The National Science Foundation Teaching Fellowship Program (NSF GK-12) at the University of Maine provides an opportunity for advanced graduate students in science, mathematics and engineering to bring their knowledge, as well as the latest equipment, to stud...
C Howell, L Gott, B Meehan
Micromorphological Characteristics of Degradation in Bamboo Attacked by White Rot Fungus Lentinus edodes
2006 - IRG/WP 06-10575
In comparison with micromorphological works for wood decay, little known is about the decay pattern of bamboos by wood decay fungi. The present work was undertaken to understand the general degradation pattern of bamboo and the influence of polylaminate layers in bamboo fiber walls on the restriction of fungal decay. The weight loss of bamboo species Phyllostachys puberscens against the white rot ...
Chang Hyun Cho, Kwang Ho Lee, Yoon Soo Kim
The bacterial transformation of organic biocides; a common mechanism?
2006 - IRG/WP 06-10585
It was found that a number of unformulated organic biocides showed a susceptibility to degradation by proteobacteria. Exposure of tebuconazole, a candidate biocide, chlorothalonil and IPBC to a Ralstonia strain was found to result in biocide detoxification, as demonstrated through HPLC and a bioassay. Exposure of the biocides to a previously identified extracellular factor was also found to resu...
D F Wallace, D J Dickinson