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Bacterial Degradation of Pentachlorophenol Indicated in Groundwater Undergoing Long Term In-Situ Remediation
2016 - IRG/WP 16-50318
Pentachlorophenol (PCP, Penta) is a worldwide soil and water contaminant. The pervasive use of PCP as a fungicide, herbicide, pesticide, and as preservative for wood products has led to its global distribution. It is a highly effective preventative measure for most invasive insects, bacteria, fungi, and molds, as well as an excellent wood protection treatment. This study examined a known PCP contaminated site that has been undergoing remediation treatment since 2000 to determine if PCP degrading bacteria could be identified using molecular techniques. Bacteria were identified by sequencing the 16s rDNA fragment from DNA extracted from groundwater cultures and comparing those sequences to a database using a basic local alignment search tool, BLAST. The PCP-degraders Burkholderia cepacia and Flavobacterium (Sphingobium) chlorophenolicum were identified in multiple wells, as were the 4-chlorophenol degrader Herbaspirillum chlorophenolicum, and the common soil bacteria Pseudomonas sp., Aquaspirillum sp., and Rhodocista sp., among others. Numerous bacterial samples also appeared in the results as “uncultured”. Diversity measures including species richness, Simpson’s and Shannon’s indices, and species evenness were calculated from operational taxonomic unit results for each well at each sampling point in order to better understand changes in the bacterial community. Species richness tended to be higher at wells further away from the biosparging line, while diversity and evenness varied throughout the area. Correlations between PCP concentration, operational taxonomic units, and distance from biosparging wells were determined by Pearson’s product-moment correlation and Spearman’s rank correlation. Positive correlations were found between distance from biosparging wells and PCP concentration, species richness and distance, and to a smaller degree, diversity and distance. Biosparging remediation has a significant impact on the types of PCP-degrading bacteria within the groundwater matrix, and installations of this type of treatment should be applied to maximize the use of the native bacteria to assist in degradation of the contaminant.
C E Stokes, H Borazjani, L Prewitt

Wood and filter paper degradation, phenol oxidase and one-electron oxidation activities by the white rot fungus Ceriporiopsis subvermispora
2003 - IRG/WP 03-10486
The activities of one-electron oxidation and phenol oxidase during incubation of cultures of the white-rot basidiomycete Ceriporiopsis subvermispora containing either glucose or wood were periodically measured. Further, the degradation activities against wood and filter paper were examined during the course of cultivation. Weight losses of Japanese beech wood and Japanese cedar wood after 12 weeks were about 20% and 15%, respectively. Weight loss of filter paper was about 23% after 9 weeks. The one-electron oxidation and phenol oxidase activities in wood-containing cultures were higher than those in glucose-containing cultures. Extracellular low-molecular-weight substance has been isolated and has been characterized to compare with the substances from other wood degrading fungi that catalyze a redox reaction between O2 and electron donors to produce hydroxyl radicals. The mechanism on wood degradation caused by the white-rot fungus C. subvermispora is discussed.
H Tanaka, S Itakura, A Enoki

Phenol oxidase activity and one-electron oxidation activity in wood degradation by soft-rot deuteromycetes
2007 - IRG/WP 07-10615
Wood degradation, one-electron oxidation activity as assayed by ethylene generation from 2-keto-4-thiomethylbutyric acid (KTBA), and phenol oxidase activity were measured in cultures of six deuteromyce fungi, with glucose or wood as the carbon source. The four fungi that degraded Japanese beech wood had higher one-electron oxidation activities in wood-containing cultures than in glucose-containing cultures. These four fungi also had measurable phenol oxidase activity in wood-containing cultures, but not in glucose-containing cultures. The two mould fungi that did not significantly degrade wood had no phenol oxidase activity in either wood- or glucose-containing cultures. The one-electron oxidation activity in intact cultures of the soft-rot deuteromycetes was roughly related with the rate of mass loss during wood degradation in those cultures. However, there was no clear relationship between phenol oxidase activity and either one-electron oxidation activity or the rate of wood mass loss, either over time, or in total. Most of the one-electron oxidation activity resulted from phenol oxidase and hydroxyl radical. Most of the phenol oxidase activity resulted from laccase. Furthermore, the mechanism of wood degradation by one of these deuteromycete fungi, Graphium sp., was investigated. Most of the phenol oxidase activity appeared to derive from laccase. Most of the ethylene generation from KTBA was attributed to hydroxyl radicals, produced by a low-molecular-mass substance in the extracellular media. This substance was composed of protein, carbohydrates, and Fe(II), and catalyzed redox reactions between O2 and unidentified electron donors, to produce hydroxyl radicals via H2O2. It is suggested that hydroxyl radicals may produce new phenolic substructures on the lignin polymer, making it susceptible to attack by laccase. Thus, one-electron oxidation acitivity and laccase activity are both important in wood degradation by Graphium sp.
H Tanaka, M Yamakawa, S Itakura, A Enoki

Microbiological degradation of wooden piles in building foundations
1988 - IRG/WP 1370
White rot, soft rot and bacterial attack have been detected in softwood piles under buildings. In some cases bacteria were found to be the main degradation organisms in the studied piles. The water content of degraded piles was very high. The compression strength was quite low also in the piles deteriorated by bacteria. The density of wood was very variable, and the degree of degradation could not be evaluated according to density analyses.
L Paajanen, H Viitanen

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. The extent of damage to wood cells due to microbial activity varied, combined fungal and bacterial attack having the most damaging impact.
A P Singh, M E Hedley, D R Page, C S Han, K Atisongkroh

Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observed followed after 40 days exposure by extensive separation of individual fibres at the interface of the middle lamella and secondary wall. Degradation of the S2 layer of the cell wall revealed corrugations orientated parallel to the fibre axis suggesting preferential removal of cell wall components. Further degradation proceeded by progressive delamination and checking of the S2 and erosion of the S3 cell wall layer. In addition to the above changes preferential degradation of the rays was observed in radial (R.L.S.) and tangential (T.L.S.) longitudinal surfaces.
P D Evans, S Thein

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 other wall areas in Alstonia scholaris wood cells were severely degraded. The size comparison indicated vestures to be considerably smaller than TB, and we suspect that this may primarily be the reason why vestures in Alstonia scholaris wood were found to be resistant to degradation by TB.
A P Singh, T Nilsson, G F Daniel

Effect of medium-term degradation of beech wood by erosive (Phanerochaete chrysosporium) and lignin-selective (Ceriporiopsis subvermispora) strains of white rot fungi on its selected physical properties
2004 - IRG/WP 04-40292
At the Faculty of Wood Sciences and Technology a fungal delignification of normal and tension beech wood by erosive and lignin-selective strains white-rot fungi has been studied. The pre-treatment of both kind of wood samples was accompanied by partial delignification and apparent changes of their physical properties influencing the polar liquids penetration.
R Solár, S Kurjatko, M Mamonová, J Hudec

Detoxification of preservatives: Tri-n-butyltin oxide as a biocide
1982 - IRG/WP 1156
T E Dudley-Brendell, D J Dickinson

The present classification of wood degradation factors
1994 - IRG/WP 94-10071
The revised version of classification of wood degradation factors is presented after discussion and remarks sended by IRG-Members. The classification contains the biotic and abiotic factors in two aspects: etiological and symptomatical.
J Wazny

Airborne algae as a wood degradation factor
1992 - IRG/WP 92-1549
The occurrence of airborne (aerophytic) algae on wood is a very frequent phenomenon. However, there is currently a lack of information concerning their effect on the wood tissue. Some important genus of algae infesting wood under natural conditions are listed, as well as the results of experimental studies in the "in vitro" culture concerning the effect of two selected algal species on some physico-mechanical properties and on the structure of beech and Scots pine woods.
K J Krajewski, J Wazny

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

Studies of the distribution and degradation of tributyltin naphthenate in double-vacuum treated wood
1983 - IRG/WP 3230
The effects of forced solvent evaporation by kilning redwood (Pinus sylvestris) that has been double-vacuum treated with tributyltin naphthenate (TBTN) have been investigated. Contrary to previous studies reported, it has been shown that forced evaporation can have a considerable influence on the losses of the fungicide. It has been found that, whether the solvent is allowed to evaporate slowly or the evaporation is forced by kilning, the TBTN breaks down considerably in freshly treated wood. In view of the implications of this work for the long-term effectiveness of TBTN further studies are called for.
J Jermer, M-L Edlund, W Hintze, S V Ohlsson

Accelerated ageing of preservatives in treated wood
1988 - IRG/WP 3476
New preservatives are tested in the laboratory and often in field tests before they are used commercially. Some preservatives, however, tested in the laboratory do not show the expected stability when used in service. The differences between laboratory tests and practical use can never be completely eliminated but must be minimized as far as possible by relevant testing methods. Studies of the effect of different accelerated ageing procedures on the chemical degradation and the wood preserving capacity of six different fungicides or combinations thereof have been carried out. Chemicals tested were tributyltinoxide (TBTO), tributyltin naphthenate (TBTN), furmecyclox, benzalkoniumchloride (AAC) + guazatin and pentachlorophenol. The ageing procedures included exposure of test specimens in a wind tunnel (according to EN 73), in an oven at 40°C, 60°C and 70°C, leaching (according to EN 84) and combinations of these procedures. The influence of the different accelerated ageing procedures on the chemical degradation and toxic effect of different fungicides was obvious and, for some procedures and chemicals, comparable with experiences from practice.
M-L Edlund, B Henningsson, B Jensen, C-E Sundman

Contribution to study of the degradation caused in Pinus spp. poles used in field test
1989 - IRG/WP 1417
The study of the degradation produced by soil natural microflora on wood in contact with it in the field, has been going on for several years now. Our contribution to this aim in the present work has dealt with the possible relationship of the microorganisms in the soil. The microscopic visualization of wood colonization by the microorganisms, and the chemical analysis of the degraded wood compared with the undergraded.
M T De Troya, A Garcia, M J Pozuelo, A M Navarrete, A Cabanas

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 using TEM demonstrated the presence of H2O2 within the fungal hyphae. Furthermore, our results give an indication of the diffusion of extarcellular H2O2 from brown-rot decay fungi into the intact wood cell walls in the early stages of decay.
Yoon Soo Kim, Seung-Gon Wi

Testing of termiticides in soil by a new laboratory method with regard to Phoxim for replacement of chlorinated hydrocarbons
1986 - IRG/WP 1292
In comparison to chlorinated hydrocarbons insecticides of the compound classes organophosphates, carbamates and pyrethroids were tested according to an earlier described soil-test in the laboratory. The following termite-species were used: Heterotermes indicola, Reticulitermes santonensis and in addition Reticulitermes flavipes, Reticulitermes lucifugus, Reticulitermes speratus and Coptotermes formosanus (Rhinotermitidae). The method gives reliable results. Criteria for evaluation are mortality and penetration of the termites into the treated soil. According to this test organophosphates, specially phoxim, have a good potential to replace chlorinated hydrocarbons.
R Pospischil

A comparison of the effectiveness of a vacuum oven and a wind tunnel in the accelerated ageing of treated wood by evaporation
1989 - IRG/WP 2334
R J Orsler, G E Holland

A laboratory soil-block decay evaluation of plywoods edge-treated with preservatives
1982 - IRG/WP 2174
Preservative-treated plywood used under conditions or severe decay hazard frequently has its original, or cut edges, protected by the application of a field-cut preservative. This study uses a laboratory test method to compare the efficacy of four commercial preservative treatments against two commonly occurring brown-rot fungi. The results are not meant to indicate the service life of such treated plywood.
R S Smith, A Byrne

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

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. Correlated T.E.M. and T.E.M.-EDAX studies showed most of the preservative elements to remain outside the bacteria associated with bacterial tunnel wall and cross-wall extracellular secretions. T.E.M.-EDAX showed the levels of preservative elements present in the tunnel walls and cross walls to often greatly exceel that recorded in neighbouring S2 cell wall regions, while studies on the bacteria showed that only copper and very low levels of chromium and arsenic had entered the cells. Observations suggested that the metals found within the cells were associated with electron-dense deposits or inclusions within the nuclear region or cell cytoplasm, the deposits often containing high levels of phosphorus and calcium together with lesser levels of other cations. The study also provided evidence for the direct visualisation of CCA preservative elements within fibre walls using T.E.M. without any form of secondary chemical enhancing, and in addition, considerable new information on the nature and structure of the single celled, Gram-negative, motile bacteria involved in the decay.
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 fibre walls under the light microscope suggests that extractives may also permeate fibre walls. In parenchyma, extractives are present in large amounts in the lumen. Inner areas of parenchyma walls are also heavily permeated. The degradation of Eusideroxylon zwageri wood is markedly slower than any wood species we have examined before. However, in advanced stages of TB attack all areas of the fibre, except corner middle lamellae and extractive filled lumen, are heavily degraded. The degradation of Eusideroxylon zwageri wood involves other differences. The TB attack of the fibre wall starts from the S1 layer moving inwards and the tunnels formed vary greatly in their form, ranging from long and relatively straight to "S","V", hook, folded and convoluted forms. These variations from previously observed appearances most likely reflect differences in the thickness and chemical composition of the fibre wall of Eusideroxylon zwageri wood from the woods examined previously.
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 of hours. White crystalline material observed on the surface of treated wood was identified as tributyltin acetate (TBTA). Other tributyltin esters, dibutyltin ethers, and butyltin chlorides were also identified.
K J Archer, R Meder

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

Lignin degradation by wood-degrading fungi
1986 - IRG/WP 1310
The wood-degrading white-rot fungus Phanerochaete chrysosporium, has been the subject of intensive research in recent years and, based upon isolation of the extracelluar enzyme ligninase, major advances have now been made toward elucidating the mechanism by which this fungus degrades lignin. From these developments, a model emerges which could explain the process by which wood-degrading fungi in general, attack lignin.
P J Harvey, H E Schoemaker, J M Palmer

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