Changes in sorption and electrical properties of wood caused by fungal decay

Holzforschung ◽  
2019 ◽  
Vol 73 (5) ◽  
pp. 445-455 ◽  
Author(s):  
Christian Brischke ◽  
Simon Stricker ◽  
Linda Meyer-Veltrup ◽  
Lukas Emmerich
Keyword(s):  
Beech Wood ◽  
Sorption Isotherms ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
White Rot Fungus ◽  
Decayed Wood ◽  
Vapor Sorption ◽  
Fungal Decay ◽  
Dynamic Vapor Sorption

Abstract As wet wood is prone to degradation by wood-destroying fungi, the monitoring of the moisture content (MC) of wood can be used to quantify the risk of fungal infestation. Fungal decay alters the sorption and electrical conductivity of wood, and thus the goal of the present study was to measure the electrical resistance (R) of wood after fungal decay as a function of MC. Scots pine sapwood (Pinus sylvestris L.) and European beech wood (Fagus sylvatica L.) were submitted to decay by Coniophora puteana (a brown rot fungus, BR) and Trametes versicolor (a white rot fungus, WR) and the mass loss (ML) due to the fungal metabolism was measured. The sorption isotherms were determined by dynamic vapor sorption (DVS), and comparative gravimetric- and R-based MC measurements were conducted. BR and WR reduced the sorption of wood and lowered its R in the hygroscopic range, where the decay led to an overestimation of wood MC, while wood MC was dramatically underestimated above fiber saturation (FS). Specimens showed an MC well above FS if measured directly after harvesting and an increased R compared to undecayed wood at a given MC. BR-decayed specimens were dried and rewetted, and such specimens showed an elevated R beyond FS. In the case of WR-decayed wood, the R was reduced at a given MC.

scholarly journals The Impact of Paraffin-Thermal Modification of Beech Wood on Its Biological, Physical and Mechanical Properties

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1102 ◽  
Author(s):  
Ladislav Reinprecht ◽  
Miroslav Repák
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Beech Wood ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
White Rot Fungus ◽  
Poria Placenta ◽  
The Impact

The European beech (Fagus sylvatica L.) wood was thermally modified in the presence of paraffin at the temperatures of 190 or 210 °C for 1, 2, 3 or 4 h. A significant increase in its resistance to the brown-rot fungus Poria placenta (by 71.4%–98.4%) and the white-rot fungus Trametes versicolor (by 50.1%–99.5%) was observed as a result of all modification modes. However, an increase in the resistance of beech wood surfaces to the mold Aspergillus niger was achieved only under more severe modification regimes taking 4 h at 190 or 210 °C. Water resistance of paraffin-thermally modified beech wood improved—soaking reduced by 30.2%–35.8% and volume swelling by 26.8%–62.9% after 336 h of exposure in water. On the contrary, its mechanical properties worsened—impact bending strength decreased by 17.8%–48.3% and Brinell hardness by 2.4%–63.9%.

The fungal resistance of wood modified with glutaraldehyde

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Zefang Xiao ◽  
Yanjun Xie ◽  
Carsten Mai
Keyword(s):  
Scots Pine ◽  
Beech Wood ◽  
Weight Percent Gain ◽  
Brown Rot ◽  
European Beech ◽  
Soft Rot ◽  
Weight Percent ◽  
Fungal Resistance ◽  
White Rot ◽  
White Rot Fungus

Abstract Scots pine sapwood (Pinus sylvestris L.) and European beech wood (Fagus sylvatica L.) were treated with glutaraldehyde (GA) in aqueous solution in the presence of magnesium chloride as a catalyst to evaluate the durability improvement towards staining and rot fungi. The GA modified specimens were dipped in a spore suspension of the blue stain fungus Aureobasidium pullulans and incubated for 8 weeks. The growth on both pine and beech wood was restrained, when the weight percent gain (WPG) of the specimens was above 7%. Under this condition, GA-modified beech wood did not suffer any mass loss after incubation with the white rot fungus Trametes versicolor. The threshold to prevent decay of beech and pine specimens towards the brown rot fungus Coniophora puteana was at a WPG of only 3%. GA treatment to a WPG over 6% protected the Scots pine stakes from soft rot decay during 32 weeks’ exposure according to ENv 807 (2001).

scholarly journals Ability of some species of fungi of the Basidiomycetes class to degrade cellulose and lignocellulose substrates

2014 ◽  
Vol 19 (2) ◽  
pp. 323-330
Author(s):  
Zdzisław Tagoński
Keyword(s):  
Beech Wood ◽  
Brown Rot ◽  
White Rot ◽  
White Rot Fungus ◽  
Cellulolytic Enzymes ◽  
Pine Wood ◽  
Wood Meal ◽  
Fomes Fomentarius

Studies were carried-out on the ability of 18 strains of 15 white-rot and brown-rot basidiomycetons fungi to degrade wood components and to synthesize cellulolytic enzymes and laccase. 28,5% lignin and 26,1% carbohydrates of pine wood meal, 46,2% lignin and 67,8% carbohydrates of beech wood meal was degraded after 6 weeks incubation by the white-rot fungus <i>Phanerochate chrysosporium</i>. The highest activity of laccase was obtained in from fungi <i>Coriotus zonatus</i> and <i>Fomes fomentarius</i>.

Investigation of fungal decay of poplar wood treated with pistachio resin

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 779-788
Author(s):  
Maede Ahadnezhad ◽  
Soheila Izadyar ◽  
Davood Efhamisisi
Keyword(s):  
Mass Loss ◽  
Trametes Versicolor ◽  
Populus Deltoides ◽  
Treated Wood ◽  
Brown Rot ◽  
White Rot ◽  
White Rot Fungus ◽  
Poplar Wood ◽  
Fungal Decay ◽  
Brown Rot Fungus

The density, swelling, and fungal decay of poplar (Populus deltoides) wood treated with pistachio resin (PR) obtained from Pistacia atlantica were investigated. The white-rot fungus Trametes versicolor and the brown-rot fungus Coniophora puteana were used. Methanolic solutions of PR with different concentrations of 1%, 6%, 12%, and 15% were used as the preservative solution. Wood samples were saturated by two different vacuum/pressure (V/P) and dipping methods. The density, volumetric swelling of treated wood, and their mass loss (ML) caused by fungal decay were determined. The density of treated species increased to 15.4% and 5.8% for V/P and dipping methods, respectively, at 15% PR concentration. The volumetric swelling of the treated samples was reduced to 24.5% and 16.8% for V/P and dipping procedure, respectively, at 15% PR concentration. The mass loss of treated samples after exposure to T. versicolor was less than the untreated one (17.4% for V/P and 22.6% for dipping methods at 15% PR concentration). The results showed the better performance of V/P treatment in promotion of wood durability against fungal decay than the dipping method.

Decay resistance of wood treated with amino-silicone compounds

Holzforschung ◽  
2008 ◽  
Vol 62 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Oliver Weigenand ◽  
Miha Humar ◽  
Geoffrey Daniel ◽  
Holger Militz ◽  
Carsten Mai
Keyword(s):  
Beech Wood ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Decay Resistance ◽  
Solute Concentration ◽  
White Rot ◽  
White Rot Fungus ◽  
European Standard ◽  
Brown Rot Fungi ◽  
Amino Silicone

AbstractAn amino-silicone (AS; amino-polydimethylsiloxane) micro-emulsion was tested for its suitability to preserve wood against basidiomycetes in a mini-block experiment and in a test according to the European standard (1996) EN 113. Decay resistance was assessed against the white rot fungiTrametes versicolor,Ceriporiopsis subvermispora, andHypoxylon fragiforme, as well as the brown rot fungiConiophora puteana,Antrodia vaillantii,Gloeophyllum trabeumandSerpula lacrymans. Pine sapwood and beech wood were treated with AS emulsions at solute concentration levels of 2%, 5% and 15%. The mini-blocks treated with 15% concentrations of AS resisted decay byT. versicolorandC. puteanaover a long time (12 weeks), while samples treated with low and moderate concentrations underwent considerable mass losses. Accordingly, microscopic studies revealed a high degree of colonisation by the white rot fungus and loss of cell wall integrity (brown rot) in samples treated with 2% AS. At high AS content (15%), no or only initial stages of decay could be observed. In the European standard (1996) test EN 113, the mass loss in all fungal cultures except for the white rot ascomyceteH. fragiformewas below 5%, when the samples were treated with 15% AS. The effect of low and moderate AS concentration on the decay resistance was dependent on the fungal strain. The mode of action of AS treatment against basidiomycete decay is discussed.

Detection of fungal decay by high-energy multiple impact (HEMI) testing

Holzforschung ◽  
2006 ◽  
Vol 60 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Christian Brischke ◽  
Christian Robert Welzbacher ◽  
Andreas Otto Rapp
Keyword(s):  
Structural Changes ◽  
Brown Rot ◽  
High Energy ◽  
White Rot ◽  
Fungal Decay ◽  
Highly Correlated ◽  
Thermally Modified Wood ◽  
Impact Milling ◽  
Multiple Impact ◽  
Steel Balls

Abstract The suitability of a previously described high-energy multiple impact (HEMI) test for the detection of early fungal decay was examined. The HEMI test characterises the treatment severity of thermally modified wood by stressing the treated material by thousands of impacts of pounding steel balls. This method differentiates between heat treatment intensities, which are manifest as structural changes in the wood. Similar changes in wood structure are known for wood decayed by fungi. Pine (Pinus sylvestris L.) decayed by brown rot and beech (Fagus sylvatica L.) decayed by white rot were tested. Mass loss caused by fungal decay and resistance to impact milling (RIM) determined in HEMI tests were found to be highly correlated. Testing of non-degraded pine, beech, and ash (Fraxinus exelsior L.) showed only marginal effects of wood density on RIM. Furthermore, annual ring angles and RIM of spruce (Picea abies Karst.) were not correlated. Accordingly, the detection of RIM reduction in decayed wood is not masked by variations in density and orientation of the annual rings. Previous results showed no adverse effects of weathering on RIM. Thus, the detection of fungal decay with HEMI tests is feasible not only for laboratory purposes, but also for wood in outdoor applications that has already undergone weathering.

Fungal decay of spruce and beech wood assessed by near-infrared spectroscopy in combination with uni- and multivariate data analysis

Holzforschung ◽  
2007 ◽  
Vol 61 (6) ◽  
pp. 680-687 ◽  
Author(s):  
Karin Fackler ◽  
Manfred Schwanninger ◽  
Cornelia Gradinger ◽  
Ewald Srebotnik ◽  
Barbara Hinterstoisser ◽  
...  
Keyword(s):  
Data Analysis ◽  
Multivariate Data Analysis ◽  
Near Infrared ◽  
Lignin Content ◽  
Beech Wood ◽  
Multivariate Data ◽  
Principal Component ◽  
Brown Rot ◽  
White Rot ◽  
Least Squares Regression

Abstract Wood is colonised and degraded by a variety of micro-organisms, the most efficient ones are wood-rotting basidiomycetes. Microbial decay processes cause damage to wooden constructions, but also have great potential as biotechnological tools to change the properties of wood surfaces and of sound wood. Standard methods to evaluate changes in infected wood, e.g., EN350-1 1994, are time-consuming. Rapid FT-NIR spectroscopic methods are also suitable for this purpose. In this paper, degradation experiments on surfaces of spruce (Picea abies L. Karst) and beech (Fagus silvatica L.) were carried out with white rot basidiomycetes or the ascomycete Hypoxylon fragiforme. Experiments with brown rot or soft rot caused by Chaetomium globosum were also performed. FT-NIR spectra collected from the degraded wood were subjected to principal component analysis. The lignin content and mass loss of the specimens were estimated based on univariate or multivariate data analysis (partial least squares regression).

Iron and calcium translocation from pure gypsum and iron-amended gypsum by two brown rot fungi and a white rot fungus

Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Jonathan S. Schilling ◽  
Kaitlyn M. Bissonnette
Keyword(s):  
Building Materials ◽  
Woody Debris ◽  
White Rot Fungi ◽  
Brown Rot ◽  
White Rot ◽  
White Rot Fungus ◽  
Irpex Lacteus ◽  
Brown Rot Fungi ◽  
Ca Oxalate ◽  
Iron And Calcium

AbstractWood-degrading fungi commonly grow in contact with calcium (Ca)-containing building materials and may import Ca and iron (Fe) from soil into forest woody debris. For brown rot fungi, imported Ca2+may neutralize oxalate, while Fe3+may facilitate Fenton-based degradation mechanisms. We previously demonstrated, in two independent trials, that degradation of spruce by wood-degrading fungi was not promoted when Ca or Fe were imported from gypsum or metallic Fe, respectively. Here, we tested pine wood with lower endogenous Ca than the spruce blocks used in prior experiments, and included a pure gypsum treatment and one amended with 1% with FeSO4. Electron microscopy with microanalysis verified that brown rot fungiSerpula himantioidesandGloeophyllum trabeumand the white rot fungusIrpex lacteusgrew on gypsum and produced iron-free Ca-oxalate crystals away from the gypsum surface. Wood cation analysis verified significant Fe import by both brown rot isolates in Fe-containing treatments. Wood degradation was highest in Fe-gypsum-containing treatments for all three fungi, although only wood degraded byI. lacteushad significant Ca import. We suggest that Fe impurities may not exacerbate brown rot, and that both brown and white rot fungi may utilize Ca-containing materials.

Études mycologique, entomologique et physico-chimique de troncs de Betula pendula en voie de dégradation. I. Répartition spatiale de l'état physico-chimique et de la mycoflore des troncs

1996 ◽  
Vol 74 (10) ◽  
pp. 1657-1664 ◽  
Author(s):  
Marie-Hélène Prince Sigrist ◽  
Daniel Job
Keyword(s):  
Fungal Biomass ◽  
Betula Pendula ◽  
Lignin Content ◽  
Brown Rot ◽  
Absorption Capacity ◽  
Decay Process ◽  
White Rot ◽  
Water Absorption Capacity ◽  
Decayed Wood ◽  
Brown Rot Decay

Decaying Betula pendula Roth trunks (measuring about 6 m in length) with brown rot or white rot were analyzed for the followings: stage of decay, wood structure, porosity, chemical composition of decayed wood, spatial distribution of fungal biomass, and mycoflora diversity. The fungal biomass in the trunks, although heterogeneous, is higher in white rot than in brown rot. As expected, the lignin/holocellulose ratio is higher in brown rot than in white rot (maximum 14.83 versus 0.67). Brown rot is generally more porous than white rot and presents a higher water absorption capacity but it retains less air. The results show that the basidiomycetes mycoflora is active in the white rot decay process. However it is not involved in the brown rot decay process because the wood is already much decayed (as much as 80% and more of lignin content). With the exception of moulds, the only mycoflora that could be isolated repetitively from the brown rot station was in fact pockets of white rot. Moreover, in brown rot, none of the epiflora matched the isolated endoflora. Keywords: white rot, brown rot, mycoflora, biomass.

scholarly journals Efficacy of Caffeine Treatment for Wood Protection—Influence of Wood and Fungi Species

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3758
Author(s):  
Miloš Pánek ◽  
Vlastimil Borůvka ◽  
Jana Nábělková ◽  
Kristýna Šimůnková ◽  
Aleš Zeidler ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Beech Wood ◽  
Ecological Integrity ◽  
Treated Wood ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
European Beech ◽  
Brown Rot Fungi ◽  
Wood Protection ◽  
Caffeine Treatment

In the future, we can expect increased requirements to the health and ecological integrity of biocides used for the protection of wood against bio-attacks, and it is therefore necessary to search for and thoroughly test new active substances. Caffeine has been shown to have biocidal efficacy against wood-destroying fungi, moulds and insects. The aim of the research was to determine whether the effectiveness of caffeine, as a fungicide of natural origin, is affected by a different type of treated wood. Norway spruce mature wood (Picea abies), Scots pine sapwood (Pinus sylvestris), and European beech wood (Fagus sylvatica) were tested in this work. The samples were treated using long-term dipping technology or coating (according to EN 152:2012) and then tested against selected wood-destroying brown rot fungi according to the standard EN 839:2015, wood-staining fungi according to EN 152:2012, and against mould growth according to EN 15457:2015. The penetration of caffeine solution into wood depth was also evaluated using liquid extraction chromatography, as well as the effect of the treatment used on selected physical and mechanical properties of wood. The test results showed that the type of wood used and the specific type of wood-degrading agent had a significant effect on the effectiveness of caffeine protection. The most resistant wood was the treated spruce, whereas the most susceptible to deterioration was the treated white pine and beech wood. The results of the work showed that caffeine treatment is effective against wood-destroying fungi at a concentration of 2%, and at 1% in some of the tested cases. It can be used as an ecologically acceptable short-term protection alternative against wood-staining fungi in lumber warehouses and is also partially effective against moulds. It also does not have negative effects on changes in the physical and mechanical properties of the tested wood species.

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