Stilbene impregnation retards brown-rot decay of Scots pine sapwood

Abstract Stilbenes are abundant in the heartwood of Scots pine (Pinus sylvestris L.) and are known to have strong antifungal efficiency. In this study, Scots pine sapwood blocks were impregnated with crude heartwood extract containing the stilbenes pinosylvin (PS) and the pinosylvin monomethyl ether (PSM). Impregnated blocks were submitted to brown-rot fungi, Coniophora puteana, Gloeophyllum trabeum, and Rhodonia (Poria) placenta, and fungal growth test and decay test were performed. Both tests showed that the impregnation with a high concentration of stilbenes (60 mg g-1 dry wood) significantly suppressed the growth of fungi and slowed down the decay process of wood blocks, especially in case of G. trabeum. However, chemical analysis showed that PS and PSM were degraded by all the three types of fungi, obviously via modification to resveratrol and methylresveratrol. Rhodonia placenta displayed the fastest rate of degradation. Thus, impregnation with biodegradable stilbenes could be a viable alternative for wood preservation only in service situations with low or transient risk of decay.

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Changes in chemical composition of decayed Scots pine and beech wood

Science and Engineering of Composite Materials ◽

10.1515/secm-2013-0180 ◽

2014 ◽

Vol 21 (4) ◽

pp. 589-595 ◽

Cited By ~ 6

Author(s):

Eylem Dizman Tomak

Keyword(s):

Chemical Composition ◽

Ir Spectra ◽

Scots Pine ◽

Degradation Mechanism ◽

Beech Wood ◽

Accelerated Aging ◽

Brown Rot ◽

Brown Rot Fungi ◽

Decay Test ◽

Ft Ir

AbstractIn this study, changes in chemical composition of aged and unaged Scots pine and beech wood decayed by brown-rot fungi Coniophora puteana and Poria placenta were presented by Fourier transform infrared (FT-IR) spectra. Samples were exposed to six complete cycles of accelerated aging for 12 days and then subjected to brown-rot fungi attack for 8 weeks. Weight loss of samples was found to be 25–46% depending on wood and fungi species and being aged ones. Accelerated aging treatments seemed to have a slight role on chemical composition of Scots pine and beech samples while they increased biodegradation of samples. FT-IR spectra showed degradation of wood carbohydrates revealed by reduction of the peaks responsible for hemicellulose and cellulose at 1730, 1370, 1150, and 897 cm-1 in pine and 1730, 1370, 1027, and 897 cm-1 in beech. Stronger lignin peaks at 1650, 1593, 1506, 1455, 1422, 1261, and 1230 cm-1 in pine and 1650, 1506, 1455, and 1422 cm-1 in beech were obtained after decay test. FT-IR spectra of samples were consistent with the degradation mechanism of brown-rot fungi. In general, changes in the carbohydrate and lignin peaks were greater in samples exposed to accelerated aging treatments for both wood species.

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Condensed conifer tannins as antifungal agents in liquid culture

Holzforschung ◽

10.1515/hf-2012-0154 ◽

2013 ◽

Vol 67 (7) ◽

pp. 825-832 ◽

Cited By ~ 21

Author(s):

Anna-Kaisa Anttila ◽

Anna Maria Pirttilä ◽

Hely Häggman ◽

Anni Harju ◽

Martti Venäläinen ◽

...

Keyword(s):

Growth Inhibition ◽

Fungal Growth ◽

White Rot Fungi ◽

Brown Rot ◽

Wood Preservative ◽

Soft Rot ◽

White Rot ◽

Wood Preservatives ◽

Active Components ◽

Brown Rot Fungi

Abstract In the last decades, many wood preservatives have been prohibited for their ecotoxicity. The present article is focusing on the conifer-derived condensed tannins as environment-friendly options for the substitution of artificial wood preservatives. Eight different tannin fractions were extracted from spruce cones, spruce barks, and pine cones. The parameters of tannin extraction, such as the methods of purification and concentration of active components in the extracts, have been investigated. The cone and bark extracts were tested for the growth inhibition of eight brown-rot fungi, three white-rot fungi, and four soft-rot fungi in liquid cultures. The cone tannins provided a more efficient fungal growth inhibition than bark tannins. Purification increased the antifungal properties of the extracts. The growth of brown-rot fungi was inhibited by the tannins already at low concentrations. However, the extracts were not effective against the white-rot or soft-rot fungi. More investigation is needed concerning the tannin source and the purification procedure of the extracts before tannins can be considered as an ecologically benign wood preservative.

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Cellular level chemical changes in Scots pine heartwood during incipient brown rot decay

Scientific Reports ◽

10.1038/s41598-019-41735-8 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 5

Author(s):

Tiina Belt ◽

Michael Altgen ◽

Mikko Mäkelä ◽

Tuomas Hänninen ◽

Lauri Rautkari

Keyword(s):

Scots Pine ◽

Brown Rot ◽

Cellular Level ◽

Chemical Changes ◽

Brown Rot Decay

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Decay resistance, extractive content, and water sorption capacity of Siberian larch (Larix sibirica Lebed.) heartwood timber

Holzforschung ◽

10.1515/hf.2006.017 ◽

2006 ◽

Vol 60 (1) ◽

pp. 99-103 ◽

Cited By ~ 13

Author(s):

Martti Venäläinen ◽

Anni M. Harju ◽

Nasko Terziev ◽

Tapio Laakso ◽

Pekka Saranpää

Keyword(s):

Siberian Larch ◽

Brown Rot ◽

Decay Resistance ◽

Extractive Content ◽

Strong Negative Correlation ◽

Average Mass ◽

Brown Rot Fungi ◽

Hygroscopic Properties ◽

Decay Test

Abstract The aim of this study was to find chemical or physical properties of Siberian larch heartwood timber that correlate with the variation in decay resistance. Juvenile heartwood from 24-year-old grafts of 15 clones was exposed to three brown-rot fungi according to the standard in vitro decay test (European standard EN 113). The mass losses caused by the brown rot fungi Coniophora puteana, Poria placenta, and Gloeophyllum trabeum were 20%, 28% and 17% of the dry mass, respectively. The average mass loss over the three fungi had a strong negative correlation with the concentration of taxifolin (r=–0.673, P=0.006), as well as with the concentration of total phenolics determined by the Folin-Ciocalteu assay (r=–0.677, P=0.006). Thus, the concentration of flavonoids is a promising property for indirect measurement of the decay resistance of Siberian larch timber. The most abundant heartwood extractives, arabinogalactans, had a non-significant relationship with the decay resistance, but their concentration correlated positively with the capacity of the wood to adsorb water (r=0.736, P=0.002). The hygroscopic properties of the wood or the wood density were not associated with the decay resistance.

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Efficacy of Pinosylvins against White-Rot and Brown-Rot Fungi

Holzforschung ◽

10.1515/hf.1999.081 ◽

1999 ◽

Vol 53 (5) ◽

pp. 491-497 ◽

Cited By ~ 56

Author(s):

Catherine C. Celimene ◽

Jessie A. Micales ◽

Leslie Ferge ◽

Raymond A. Young

Keyword(s):

Picea Glauca ◽

Pinus Banksiana ◽

White Rot Fungi ◽

Brown Rot ◽

Monomethyl Ether ◽

Decay Resistance ◽

White Rot ◽

Red Maple ◽

Brown Rot Fungi ◽

Agar Media

Summary Three stilbenes, pinosylvin (PS), pinosylvin monomethyl ether (PSM) and pinosylvin dimethyl ether (PSD), were extracted from white spruce (Picea glauca), jack pine (Pinus banksiana), and red pine (Pinus resinosa) pine cones, and their structures were confirmed by spectroscopic and chromatographic (HPLC, GC/MS, NMR and FTIR) analysis. PS, PSM, PSD or a 1:1:1 mixture of these stilbenes at concentrations of 0.1 % and 1.0 % were examined for their fungal inhibitory activity by two bioassay methods. Growth of white-rot fungi (Trametes versicolor and Phanerochaete chrysosporium), and brown-rot fungi (Neolentinus lepideus, Gloeophyllum trabeum and Postia placenta) on agar media in the presence of each of the stilbenes or a 1:1:1 mixture inhibited growth of white-rot fungi, but slightly stimulated growth of brown-rot fungi. Soil-block assays, conditions more representative of those found in nature, did not correlate with those from the screening on agar media. PS, PSM, PSD or a 1:1:1 mixture of the three compounds at concentrations of 0.1 % and 1.0 % did not impart any significant decay resistance to white-rot fungi inoculated on a hardwood (Red maple). However under the same conditions, decay resistance was observed against brown-rot fungi on a softwood (Southern yellow pine). It appears that stilbenes at least partially contribute to wood decay resistance against brown-rot fungi.

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Initial Rhodonia placenta Gene Expression in Acetylated Wood: Group-Wise Upregulation of Non-Enzymatic Oxidative Wood Degradation Genes Depending on the Treatment Level

Forests ◽

10.3390/f10121117 ◽

2019 ◽

Vol 10 (12) ◽

pp. 1117 ◽

Cited By ~ 4

Author(s):

Martina Kölle ◽

Rebecka Ringman ◽

Annica Pilgård

Keyword(s):

Hydrolytic Enzymes ◽

Oxidative Degradation ◽

Brown Rot ◽

Treatment Level ◽

Wood Degradation ◽

Weight Percentage ◽

Brown Rot Fungi ◽

Number Of Genes ◽

Brown Rot Decay ◽

Underlying Mechanisms

Acetylation has been shown to delay fungal decay, but the underlying mechanisms are poorly understood. Brown-rot fungi, such as Rhodonia placenta (Fr.) Niemelä, K.H. Larss. & Schigel, degrade wood in two steps, i.e., oxidative depolymerization followed by secretion of hydrolytic enzymes. Since separating the two degradation steps has been proven challenging, a new sample design was applied to the task. The aim of this study was to compare the expression of 10 genes during the initial decay phase in wood and wood acetylated to three different weight percentage gains (WPG). The results showed that not all genes thought to play a role in initiating brown-rot decay are upregulated. Furthermore, the results indicate that R. placenta upregulates an increasing number of genes involved in the oxidative degradation phase with increasing WPG.

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Degradation of chemically modified Scots pine (Pinus sylvestris L.) with Fenton reagent

Holzforschung ◽

10.1515/hf-2014-0067 ◽

2015 ◽

Vol 69 (2) ◽

pp. 153-161 ◽

Cited By ~ 5

Author(s):

Yanjun Xie ◽

Zefang Xiao ◽

Carsten Mai

Keyword(s):

Fenton Reaction ◽

Oxidative Degradation ◽

Brown Rot ◽

Fenton Reagent ◽

Wood Degradation ◽

Weight Percentage ◽

Brown Rot Fungi ◽

Minor Losses ◽

Brown Rot Decay ◽

Modified Wood

AbstractThe Fenton reaction is supposed to play a key role in the initial wood degradation by brown rot fungi. Wood was modified with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) and glutaraldehyde (GA) to various weight percentage gains in order to study if these types of modifications are able to reduce wood degradation by Fenton reagent. Veneers modified with higher concentrations (1.2 and 2.0 mol l-1) of both chemicals exhibited minor losses in mass and tensile strength during treatment with Fenton reagent, which shows restrained oxidative degradation by hydroxyl radicals. The decomposition rate of H2O2was lower in the Fenton solutions containing modified veneers than in those containing unmodified controls. More CO2evolved in systems containing unmodified veneers than in systems with modified veneers, indicating that modification protected wood from mineralisation. The reason for the enhanced resistance of modified wood to the Fenton reaction is attributed to impeded diffusion of the reagent into the cell wall rather than to inhibition of the Fenton reaction itself. The results show that wood modification with DMDHEU and GA is able to restrain the degradation of wood by the Fenton reaction and can explain why modified wood is more resistant to brown rot decay.

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Effects of Wood Moisture Content and the Level of Acetylation on Brown Rot Decay

Forests ◽

10.3390/f11030299 ◽

2020 ◽

Vol 11 (3) ◽

pp. 299 ◽

Cited By ~ 4

Author(s):

Samuel L. Zelinka ◽

Grant T. Kirker ◽

Amy B. Bishell ◽

Samuel V. Glass

Keyword(s):

Moisture Content ◽

Mass Loss ◽

Linear Trend ◽

Fungal Growth ◽

Weight Percent Gain ◽

Brown Rot ◽

Weight Percent ◽

Wood Moisture Content ◽

Wood Moisture ◽

Brown Rot Decay

Acetylation is one of the most common types of wood modification and is commercially available throughout the world. Many studies have shown that acetylated wood is decay resistant at high levels of acetylation. Despite its widespread use, the mechanism by which acetylation prevents decay is still not fully understood. It is well known that at a given water activity, acetylation reduces the equilibrium moisture content of the wood cell wall. Furthermore, linear relationships have been found between the acetylation weight percent gain (WPG), wood moisture content, and the amount of mass loss in decay tests. This paper examines the relationships between wood moisture content and fungal growth in wood, with various levels of acetylation, by modifying the soil moisture content of standard soil block tests. The goal of the research is to determine if the reduction in fungal decay of acetylated wood is solely due to the reduction in moisture content or if there are additional antifungal effects of this chemical treatment. While a linear trend was observed between moisture content and mass loss caused by decay, it was not possible to separate out the effect of acetylation from fungal moisture generation. The data show significant deviations from previously proposed models for fungal moisture generation and suggest that these models cannot account for active moisture transport by the fungus. The study helps to advance our understanding of the role of moisture in the brown rot decay of modified wood.

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Chemical factors affecting the brown-rot decay resistance of Scots pine heartwood

Trees ◽

10.1007/s00468-002-0233-z ◽

2003 ◽

Vol 17 (3) ◽

pp. 263-268 ◽

Cited By ~ 41

Author(s):

Anni M. Harju ◽

Martti Venäläinen ◽

Seija Anttonen ◽

Hannu Viitanen ◽

Pirjo Kainulainen ◽

...

Keyword(s):

Scots Pine ◽

Brown Rot ◽

Decay Resistance ◽

Factors Affecting ◽

Chemical Factors ◽

Brown Rot Decay

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Effects of white rot and brown rot decay on the drilling resistance measurements in wood

Holzforschung ◽

10.1515/hf-2017-0204 ◽

2018 ◽

Vol 72 (10) ◽

pp. 905-913 ◽

Cited By ~ 3

Author(s):

Evgenii Sharapov ◽

Christian Brischke ◽

Holger Militz ◽

Elena Smirnova

Keyword(s):

Scots Pine ◽

Free Water ◽

Brown Rot ◽

European Beech ◽

White Rot ◽

Drilling Tool ◽

Significant Difference ◽

Brown Rot Decay ◽

Drilling Resistance ◽

The Impact

AbstractAn IML-RESI PD 400 drilling tool and a standard spade drill bit (IML System GmbH, Wiesloch, Germany) were used to study the impact of white and brown rot decay on drilling resistance (DR) measurements in wood. In total, 720 drillings were made in specimens of Scots pine (Pinus sylvestrisL.) heartwood and sapwood, European beech (Fagus sylvaticaL.) and English oak (Quercus roburL.), which were decayed byConiophora puteanaandTrametes versicolor. Drillings were made with specimens conditioned in normal climate (20°C/65% RH) and with specimens vacuum-impregnated in water. DR and feeding force (FF) were negatively correlated with mass loss (ML) due to fungal decay. The intensity of reduction was higher for DR than for FF with increasing ML for all decay types and moisture contents (MCs). A significant difference (at 95% confidence level) in DR was found between decay types using water-saturated (WS) Scots pine specimens (3–35% ML). In most cases, DR revealed a higher predictive power of the models for ML prediction than FF. Free water in decayed specimens significantly reduced the DR and FF. Hence, the effect of ML on DR and FF of decayed and WS wood was less prominent.

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