Your search resulted in 3092 documents. Displaying 25 entries per page.
Fungal and bacterial attack of CCA-treated Pinus radiata timbers from a water-cooling tower
1991 - IRG/WP 1488
Transmission electron microscopy of decaying CCA-treated Pinus radiata timbers from an industrial water cooling tower showed presence of a thick biofilm covering some areas of the wood. The biofilm contained various morphologically distinct forms of microorganisms embedded in a slime. The study provided evidence of the activity of soft rot fungi and tunnelling and erosion bacteria in wood cells. T...
A P Singh, M E Hedley, D R Page, C S Han, K Atisongkroh
Resistance of Alstonia scholaris vestures to degradation by tunnelling bacteria
1992 - IRG/WP 92-1547
Electron microscopic examination of vessels and fibre-tracheids in the wood of Alstonia scholaris exposed to tunnelling bacteria (TB) in a liquid culture showed degradation of all areas of the secondary wall. The highly lignified middle lamella was also degraded in advanced stages of TB attack. However, vestured pit membranes and vestures appeared to be resistant to degradation by TB even when oth...
A P Singh, T Nilsson, G F Daniel
Detoxification of preservatives: Tri-n-butyltin oxide as a biocide
1982 - IRG/WP 1156
T E Dudley-Brendell, D J Dickinson
Cytochemical localization of hydrogen peroxide in brown rot fungus Tyromyces palustris by cerium chloride technique
1999 - IRG/WP 99-10299
Cerium chloride (CeCl3) was used to localize H2O2 cytochemically for studying relationship between ultrastructural and functional characteristics of cellulose degradation by brown rot fungi. This technique proved very useful in localizing discrete electron-densereactionproducts at high resolution with minimal nonspecific deposition. The cytochemical localization of extracellular H2O2 by CeCl3 usin...
Yoon Soo Kim, Seung-Gon Wi
Ultrastructural and TEM-EDAX studies on the degradation of CCA treated radiata pine by tunnelling bacteria
1985 - IRG/WP 1260
An ultrastructural study was carried out on bacterial attacked Pinus radiata stakes treated with a high level (24.7 kg/m³) of Tanalith NCA preservative. The purpose of the investigation was to determine whether the organism possessed intracellular and/or extracellular detoxification mechanisms in order to overcome the high levels of copper, chrome and arsenic present within the wood fibre walls. ...
G F Daniel, T Nilsson
Ultrastructure of the attack of a naturally durable timber by tunnelling bacteria
1990 - IRG/WP 1462
The attack of the wood of Eusideroxylon zwageri, a naturally durable species, by tunnelling bacteria (TB) was examined by light microscopy and transmission electron microscopy. Observations were made primarily on fibres. Parenchyma were included in some cases. Both fibres and parenchyma are rich in extractives. In fibres, extractives are primarily present in the lumen. The amber colouration of fib...
A P Singh, T Nilsson, G F Daniel
An investigation into the stability of TBTO in LOSP-treated radiata pine
1987 - IRG/WP 3459
Nuclear magnetic resonance (NMR) spectroscopy and reverse phase paper chromatography were used to characterise the organotin compounds found in radiata pine treated with bis (tri-n-butyl) tin oxide (TBTO). Preliminary results indicate that the preservative is remarkably unstable in wood after light organic solvent preservative (LOSP) treatment. Significant decomposition of TBTO occurs in a matter ...
K J Archer, R Meder
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
Susceptibility of angiosperm sapwood to white-rot fungal colonization and subsequent degradation: a hypothesis
1997 - IRG/WP 97-10211
It has long been recognized that angiosperm sapwood in nature is relatively easily and preferentially degraded by white-rot fungi. This susceptibility to white-rot fungi is generally believed to be mainly caused by the structure and concentration of angiosperm lignin. However, an explicit explanation as to why lignin structure makes a particular wood vulnerable to white-rot colonisation and subseq...
T Schultz, D D Nicholas
The effect of didecyldimethylammonium chloride on growth of different strains of mould fungus Gliocladium roseum
1995 - IRG/WP 95-10105
The tolerance and degrading ability of different strains of Gliocladium roseum towards didecyldimethylammonium chloride (DDAC) were studied. All four of the strains of Gliocladium roseum were tolerant to DDAC and after their growth on amended malt agar, the retention of DDAC in the medium was reduced....
Yu Zheng, J N R Ruddick
Étude in vitro de la colonisation et de la dégradation structural du bois de hêtre par Coriolus versicolor (L.) Quélet
1976 - IRG/WP 158
L'attaque du bois de Hêtre par Coriolus versicolor (L.) Quélet, agent de pourriture fibreuse blanche est étudiée après des périodes d'exposition à ce champignon variant de 15 jours à trois mois. L'observation des premiers stades, c'est à dire de la colonisation du bois par les filaments de champignon est faite en microscopie optique, puis au fur et à m...
D Dirol
Proposed degradation pathway for quaternary ammonium compounds by mould fungi
1996 - IRG/WP 96-10166
One group of chemicals that has attracted considerable attention as potential wood preservatives are the quaternary ammonium compounds (QACs). Based upon results of previous research this study confirmed the degradation pathway employed in QAC-tolerant fungi. For this experiment the two dialkylammonium compounds didecyldimethylammonnium chloride and dioctyldimethylammonium chloride were used. QAC-...
J L Bürgel, J Dubois, J N R Ruddick
Degradation of the normal fibre walls of rubberwood (Hevea brasiliensis) by the tropical blue-stain fungus Botryodiplodia theobromae
1998 - IRG/WP 98-10286
Rubberwood was examined by light microscopy and transmission electron microscopy (TEM) after exposure to the common tropical sapstain fungus Botryodiplodia theobromae for four weeks to study hyphal colonisation of wood cells and to determine if this fungus also degraded lignified normal fibre cell walls in addition to the walls of non-lignified elements. Light microscopy revealed relatively large ...
A A H Wong, A P Singh
The preliminary characterization of ß-1,4-xylanase of the brown-rot fungus Gloeophyllum trabeum
1990 - IRG/WP 1447
The extracellular ß-1,4-xylanase of the brown-rot fungus, Gloeophyllum trabeum, was isolated from crude extract by chromatofocusing method (PBE 94 column chromatography). The isoelectric point was estimated to 4.2-4.8 by cromatofocusing and 4.5 by isoelectric focusing (IEF). The molecular weight of the enzyme was estimated to 37,000 dalton by SDS-PAGE. The optimal temperature for the crude extrac...
A-C Ritschkoff, M Rättö, L Viikari
Stability and performance of tributyltin compounds
1984 - IRG/WP 3275
Based on the critical examinations of the disputable permanence of tributyltin compounds in wood, this paper deals with a number of examinations of the relative evaporation, thermal stability and oxidation stability of some TBT-compounds. While thermal and oxidative stability is high for all TBT-species, the relative evaporation at elevated temperature is highly variable, and lowest for the TBT-es...
F Imsgard, B Jensen, H A B Landsiedel, H Plum
Evaluation of New Zealand staining fungi for degradation of radiata pine
1999 - IRG/WP 99-10310
This investigation sought to determine the potential of selected NZ staining fungi to induce weight loss and changes in toughness (impact bending strength) and composition in unseasoned radiata pine sapwood. Furthermore, assays were performed to eveluate enzyme production by staining fungi. Sets of side-matched specimens were inoculated with Ophiostoma floccosum, Sphaeropsis sapinea and O. plurian...
A Schirp, R L Farrell, B Kreber
Immunogold localisation of catalytic domain of endocellulase in the cellulosic substrates
1997 - IRG/WP 97-10205
The reaction of catalytic domain of endocellulase on the cellulosic substrates was visualised by using immunogold labelling procedures to obtain a better understanding of the mechanism of enzymatic cellulose hydrolysis. Polyclonal antibody was produced against the catalytic domain of endo-l, 4-ß-glucanase (EGI) from a ruminal anaerobic bacterium Ruminococcus albus F-40. Immuno-TEM works showed th...
Yoon Soo Kim, Seung-Gon Wi, Kyu Ho Myung, K Ohmiya, S Karita
Identification of terminal structures in cellulose degraded by the brown-rot fungus Postia placenta
1989 - IRG/WP 1389
To gain insight into the biochemical mechanism employed by brown-rot fungi to depolymerize cellulose, we identified the end-groups of chemically pure cellulose that had been depolymerized by the brown-rot fungus, Postia placenta. The depolymerized cellulose was acid hydrolyzed and the anion fractions isolated by ion chromatography. Sugar acids were identified by gas chromatographic and mass spectr...
T K Kirk, T L Highley, R E Ibach, M D Mozuch
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 a...
S Doi, S Ohta
Étude in vitro de la colonisation et de la dégradation structurale du bois d'aubier de Pin sylvestre par la Mérule: Serpula lacrymans Schum. ex Fr. S. F. Gray
1979 - IRG/WP 198
The degradation of Scots pine sapwood cell walls by Serpula lacrymans, a brown rot fungus, is observed after various periods of exposure from two weeks to twelve weeks. The observation by microscopy shows that the hyphae of Serpula rapidly invade the wood tissues as cell wall degradation starts. That deterioration is not gradual, it is observed to be very irregular as well within the whole of the ...
D Dirol
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
Effects of alkali treatment on some mechanical and chemical properties of creosote treated oaks
1991 - IRG/WP 2366
To date, there is a lack of information on the effects of chemical treatment on the performance of creosote preservative treated oak sleepers. This factorial experiment was designed to analyze three main effects: species (Quercus alba and Quercus rubra) creosote treatment (treated and untreated), and alkali (NaOH) soaking (0, 1, and 10 percent). The modulus of elasticity (MOE) and fiber stress at ...
P Chow, A J Reinschmidt, E J Barenberg, L C Chang
Production of exraxellular hydrogen peroxide and oxalic acid by brown-rot fungus Poria placenta
1995 - IRG/WP 95-10112
Hydrogen peroxide and oxalic acid have been suggested to be essential in the degradation of wood carbohydrates by brown-rot fungi. Hydrogen peroxide has been suggested to be one of the diffusible low molecular weight agents produced by brown-rot fungi for the degradation of wood carbohydrates by generating highly active radicals. The production of hydrogen peroxide and oxalic acid by Poria placent...
A-C Ritschkoff, M Rättö, J Buchert, L Viikari
Degradation of lignin model compounds with coordinated copper in the presence of peroxide
1998 - IRG/WP 98-10282
A novel diffusible system capable of decomposing lignin model compounds with copper, coordinators and peroxides has been proposed. When pyridine was used as a copper coordinator, two synthetic dyes, Poly-R and RBBR were intensively decolorized with Cu(II) and H2O2 in aqueous solutions at room temperature. Although reactions with Cu(II) and H2O2 produce a strong oxidant, hydroxyl radical, via a Fen...
K Koller, K Messner, T Watanabe
The rôle of lignin in the nutrition of several Australian termites
1983 - IRG/WP 1191
The ability of Nasutitermes exitiosus (Hill), Coptotermes acinaciformis (Frogatt), Coptotermes lacteus (Froggatt) and Mastotermes darwiniensis (Froggatt) to degrade 14C-lignin preparations was examined. The lower termites were unable to degrade lignin. Nasutitermes exitiosus was able to cause a 5-8% degradation of hardwood lignins and a synthetic lignin. It failed to degrade the lignin of Pinus ra...
L J Cookson