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Matthias Noll - One of the best experts on this subject based on the ideXlab platform.

  • material resistance of flame retarded wood plastic composites against fire and fungal decay
    Polymer Degradation and Stability, 2012
    Co-Authors: Annette Naumann, Matthias Noll, Ina Stephan, Henrik Seefeldt, Ulrike Braun
    Abstract:

    Flame retarded wood-plastic composites (WPCs) should allow safe application in areas of fire risk. Halogen-free flame retardants can contain high amounts of nitrogen, phosphorus or sulphur, which may serve as nutrition source for wood degrading fungi and accelerate wood decay. Therefore, the material resistance of WPCs with each of four flame retardants against both fire or fungal decay was examined in comparison to WPC without flame retardant. Expandable graphite showed the best performance against fire in cone calorimetry and radiant panel testing. Two ammonium polyphosphates and a third nitrogen-containing flame retardant were not as effective. Contrary to the possibility that flame retardants might enhance fungal decay of WPC, the opposite effect occurred in case of the wood-degrading fungi Trametes versicolor and Coniophora puteana according to determination of mass loss and decrease of bending modulus of elasticity. Only the surface mould Alternaria alternata slightly increased the degradation of WPCs with nitrogen-containing flame retardants compared to WPC without flame retardant according to mass loss data and FTIR-ATR analyses. Finally, WPC including expandable graphite as flame retardant was effective against both fire and fungal decay.

Franc Pohleven - One of the best experts on this subject based on the ideXlab platform.

Ilze Irbe - One of the best experts on this subject based on the ideXlab platform.

  • lignocellulolytic activity of Coniophora puteana and trametes versicolor in fermentation of wheat bran and decay of hydrothermally modified hardwoods
    International Biodeterioration & Biodegradation, 2014
    Co-Authors: Ilze Irbe, Bruno Andersons, Ingeborga Andersone, Vladimir Elisashvili, Mikheil D Asatiani, Anna Janberga, Vladimirs Biziks, Juris Grinins
    Abstract:

    In submerged- (SF) and solid-state fermentation (SSF) of wheat bran (WB) substrate, the brown-rot fungus Coniophora puteana produced high levels of endoglucanase, xylanase and filter paper activity (FPA) but neither laccase nor manganese-dependent peroxidase (MnP) activity was detected. SF favored the accumulation of endoglucanase (3.2 U ml−1), xylanase (9.4 U ml−1), and FPA (0.14 U ml−1) by C. puteana. Under the same cultivation conditions, the white-rot fungus Trametes versicolor secreted lower levels of hydrolytic enzymes but expressed high laccase and MnP activities in SF (0.93 U ml−1 and 1.75 U ml−1, respectively) and SSF (1.54 U ml−1 and 1.63 U ml−1, respectively) of WB. Extracellular enzymatic activities and weight loss (WL) were investigated in untreated and hydrothermally modified (HTM) birch, aspen, and alder wood blocks, exposed to C. puteana and T. versicolor. Acetone soluble extractives and cellulose content were determined in HTM hardwoods colonized by C. puteana. WL and cellulose degradation in untreated wood correlated with the high levels of cellulase activity produced by C. puteana. HTM noticeably increased decay resistance, although it was not toxic to the fungal growth and did not disturb the secretion of the enzymes involved in wood degradation.

  • Characterisation of the initial degradation stage of Scots pine (Pinus sylvestris L.) sapwood after attack by brown-rot fungus Coniophora puteana
    Biodegradation, 2011
    Co-Authors: Ilze Irbe, Bruno Andersons, Ingeborga Andersone, Guna Noldt, Tatiana Dizhbite, Nina Kurnosova, Mari Nuopponen, Derek Stewart
    Abstract:

    In our study, early period degradation (10 days) of Scots pine ( Pinus sylvestris L.) sapwood by the brown-rot fungus Coniophora puteana (Schum.: Fr.) Karst. (BAM Ebw.15) was followed at the wood chemical composition and ultrastructurelevel, and highlighted the generation of reactive oxygen species (ROS). An advanced decay period of 50 days was chosen for comparison of the degradation dynamics. Scanning UV microspectrophotometry (UMSP) analyses of lignin distribution in wood cells revealed that the linkages of lignin and polysaccharides were already disrupted in the early period of fungal attack. An increase in the lignin absorption A_280 value from 0.24 (control) to 0.44 in decayed wood was attributed to its oxidative modification which has been proposed to be generated by Fenton reaction derived ROS. The wood weight loss in the initial degradation period was 2%, whilst cellulose and lignin content decreased by 6.7% and 1%, respectively. Lignin methoxyl (–OCH_3) content decreased from 15.1% (control) to 14.2% in decayed wood. Diffuse reflectance Fourier-transform infrared (DRIFT) spectroscopy corroborated the moderate loss in the hemicellulose and lignin degradation accompanying degradation. Electron paramagnetic resonance spectra and spin trapping confirmed the generation of ROS, such as hydroxyl radicals (HO^∙), in the early wood degradation period. Our results showed that irreversible changes in wood structure started immediately after wood colonisation by fungal hyphae and the results generated here will assist in the understanding of the biochemical mechanisms of wood biodegradation by brown-rot fungi with the ultimate aim of developing novel wood protection methods.

  • on the changes of pinewood pinus sylvestris l chemical composition and ultrastructure during the attack by brown rot fungi postia placenta and Coniophora puteana
    International Biodeterioration & Biodegradation, 2006
    Co-Authors: Ilze Irbe, Bruno Andersons, Ingeborga Andersone, Jelena Chirkova, U Kallavus, O Faix
    Abstract:

    Abstract Pine sapwood blocks were exposed to brown-rot fungi Postia placenta and Coniophora puteana for 1, 2, 3, and 4 months. Ion exchange chromatography method was used to determine the changes in sugar content during brown-rot decay. The most remarkable feature was the preferred degradation of mannose both by P. placenta (80.9% weight loss) and C. puteana (77.5% weight loss) in comparison to the control. It can be interpreted as a result of the preferred degradation of the backbone chains of O -acetyl-galacto-glucomannans. For scanning electron microscopy, the wood degradation sequences obtained by the fracture method were used. The fractured surface of cell wall reflected the pattern of degradation of cellulose microfibrils. The surface of secondary wall decayed by P. placenta revealed both smooth and uneven regions throughout the test. C. puteana retained uneven cell wall surface only after the first month, while later the surface became smooth. This suggests that P. placenta tended to degrade cellulose amorphous regions more readily, while C. puteana , possessing full enzyme complement, was able to degrade both amorphous and crystalline regions more readily. The water vapor sorption method was applied for microstructural characteristics of wood. The formation of new pores of size 2.1–9.9 nm occurred during brown-rot decay, whose sizes and volume depend on the fungus culture and exposure time. It is assumed that the appearance of these pores is caused by the destruction of carbohydrates.

Jan T Bonarski - One of the best experts on this subject based on the ideXlab platform.

  • changes in strength of scots pine wood pinus silvestris l decayed by brown rot Coniophora puteana and white rot trametes versicolor
    Construction and Building Materials, 2016
    Co-Authors: Piotr Witomski, Wieslaw Olek, Jan T Bonarski
    Abstract:

    Abstract Alterations in static bending strength, compressive strength parallel to the grain and the modulus of elasticity (MOE) of Scots pine ( Pinus sylvestris L.) wood decayed by the white-rot fungus ( Trametes versicolor ) and the brown-rot fungus ( Coniophora puteana ) were investigated. The drastic decrease of the bending strength was observed for the initial phase of the decay and the changes were exponential. A 50% decrease in the property was found for 7% of mass loss in the case of brown rot and 20% for white rot. A linear decrease in compressive strength was observed with an increasing mass loss. White rot caused a 50% decrease of compression strength for the mass loss of ca. 30%, while for the brown rot the same decrease was observed for 20% of mass loss. The slowest linear changes were observed for the modulus of elasticity (MOE). In the case of white rot the MOE values were reduced by ca. 50% for a mass loss of 40%, while for brown rot a 50% decrease in the property was found in a mass decrease as low as 20%.

Ümit Cafer Yildiz - One of the best experts on this subject based on the ideXlab platform.

  • Decay resistance of scotch pine wood impregnated with Agaricus campestris bio-protective extract
    Maderas-ciencia Y Tecnologia, 2019
    Co-Authors: Sibel Yildiz, Ümit Cafer Yildiz, Ayşenur Yılmaz
    Abstract:

    In this study, it was investigated the possibilities of the use of fungal extract as wood protection solution against wood-degrading fungi. For that purpose, the decay resistance of Scotch pine wood samples, impregnated with Agaricus campestris fungal extract, was observed against the brown rot fungus Coniophora puteana. Impregnation procedure was applied at four different concentration levels and with two different extraction methods (hot water and methanol). The concentration levels were arranged as 1%, 3%, 5%, 7% for hot water and as 1.25%, 3.75%, 6.25%, 8.75% for methanol. The wood protective efficacy of extract solutions was determined by means of fungi decay test. The mass losses of the samples treated with both fungal extracts ranged from 3.53 to 20.91. The lowest mass losses in hot water (4.57%) and methanol extractions (3.53%) were seen in the samples treated at the highest concentration levels (7% and 8.75%). The wood samples impregnated at 7% and 8.75% concentration levels met the requirements of durability class 1 and were classified as very durable. Antifungal activity of methanol extract was stronger than that of the hot water extract. The variations which concentration levels were less than 7% did not have adequate protection to meet the requirements of the European norms.

  • Examination of the chemical changes in spruce wood degraded by brown-rot fungi using FT-IR and FT-Raman spectroscopy
    Vibrational Spectroscopy, 2016
    Co-Authors: Sefa Durmaz, Ümit Cafer Yildiz, Ozlem Ozgenc, Ismail Hakki Boyaci, Emir Erişir
    Abstract:

    Abstract Spruce sapwood was subjected to brown rot fungi ( Coniophora puteana ) for up to 80 days to study the degradation of the cell wall. The chemical composition of spruce sapwood that was modified by brown-rot fungi causing mass losses up to 60.99% was examined using Fourier transform infrared (FT-IR) and FT-Raman spectroscopy. During the first stage of brown rot, no changes were observed using light microscopy but electron microscopy clearly showed how the cell lumens were occupied by fungal hyphae. FT-IR and FT-Raman results revealed that carbohydrate peaks simultaneously diminished or disappeared with mass loss as decay proceeded. However, as the decay proceeded and the wood polysaccharides depolymerized, the intensity of peaks corresponding to lignin increased. However, the lignin content maintains relatively constant.

  • leaching and decay resistance of alder and pine wood treated with copper based wood preservatives
    Maderas-ciencia Y Tecnologia, 2014
    Co-Authors: Ali Temiz, Ümit Cafer Yildiz, Engin Derya Gezer, Gry Alfredsen, Gaye Kose, Selcuk Akbas, Sibel Yildiz
    Abstract:

    The objective of this study was to determine the leaching and decay resistance of Alder (Alnus glutinosa subsp. barbata) and Scots pine (Pinus sylvestris) wood samples treated with copper based preservatives. Samples were treated with CCA, ACQ, Tanalith E and Wolmanit with different concentrations. Scots pine samples were exposed the mini-block test against brown rot fungi (Poria placenta) and Coniophora puteana while alder wood samples were tested against brown rot fungi (Coniophora puteana) and white rot fungi (Coriolus versicolor). Regarding to leaching test, treated samples were impregnated with 300 ml of distilled water and after 6, 24, 48 and thereafter at 48-hour intervals, the leachate was removed and replaced with fresh distilled water according to AWPA E11. Samples of each leachate were collected and retained for copper analysis. Amount of copper released from treated wood during the leaching test was chemically analyzed with Atomic Absorption spectroscopy. Perchloric acid procedure for the digestion of wood was used according to AWPA A7-97. The amount of copper component (Qd), the cumulative quantities leached (Qc) and the average daily fluxes (FLUX) were calculated. Results shows that CCA treated samples release less copper compared to other copper based preservatives used in this study. Highest mass losses were obtained from the leached samples treated with 1% of ACQ-2200 against decay fungi.

  • biological resistance of acetylated spruce particleboards against to brown rot fungi Coniophora puteana
    Artvin Çoruh Üniversitesi Orman Fakültesi Dergisi, 2011
    Co-Authors: Eylem Dizman, Sibel Yildiz, Ümit Cafer Yildiz, Mustafa Aslan, Ali Temiz, Engin Derya Gezer
    Abstract:

    Curutucu mantarlara karsi oduna oldukca iyi koruma ve biyolojik dayanim saglayan asetillendirme teknolojisinin etkinligini yongalevhada gozlemleyebilmek amaciyla yurutulen calismada,  yaklasik %15 ve %20 agirlik kazanc degerleri verecek  sekilde 1 ve 3 saat boyunca asetillendirilen ladin yongalevhalari EN 113 standardina uygun olarak esmer curukluk mantarinin saldirisina (Coniophora puteana) maruz birakilmistir.  Calismada, asetillendirilmis levhalar ile asetillendirilmemis kontrol levhalarinin biyolojik dayanim performanslari karsilastirilmistir. Asetillendirme isleminin yongalevhalari esmer curukluk mantarlarina  karsi buyuk olcude korudugu gozlenmistir. Ozellikle 3 saat uygulanan asetillendirme islemi yogun mantar tahribatina karsi oldukca dusuk agirlik kaybi degerleri vererek iyi bir performans sergilemistir.

  • the combined effects of boron and oil heat treatment on the properties of beech and scots pine wood part 2 water absorption compression strength color changes and decay resistance
    Journal of Materials Science, 2011
    Co-Authors: Eylem Dizman Tomak, Ümit Cafer Yildiz, Hannu Viitanen, Mark Hughes
    Abstract:

    The effect of oil treatments on several properties of wood treated with boron compounds was studied: water absorption, water repellent efficiency, compression strength parallel to grain, color changes, and decay resistance against Coniophora puteana and Coriolus versicolor. Oil heat treatment evidently decreased the water absorption to approximately 20% and increased water repellent efficiency to 80–90% after 2 weeks immersion in water. Compression strength was not adversely affected by oil heat treatment at 160 °C. Oil impregnation as a second treatment step caused remarkable color changes especially in specimens pretreated with 5% boric acid. Boric acid treatment protected the specimens against brown and white rot when no leaching prior the decay test was used, but the protective effect was low when boron was leached. Oil treated specimens gave better efficiency against fungal decay compared to controls; however, the effect was not within the range of the efficacy needed for a wood preservative. Double treatment gave synergistic effect for both in unleached and leached specimens.