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

Holzforschung ◽  
2015 ◽  
Vol 69 (2) ◽  
pp. 153-161 ◽  
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.

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

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1117 ◽  
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.

Mode of action of brown rot decay resistance in phenol-formaldehyde-modified wood: resistance to Fenton’s reagent

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 253-259 ◽  
Author(s):  
Reza Hosseinpourpia ◽  
Carsten Mai
Keyword(s):  
Cell Wall ◽  
Mode Of Action ◽  
Fenton Reaction ◽  
Phenol Formaldehyde ◽  
Brown Rot ◽  
Weight Percent ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Brown Rot Decay ◽  
Modified Wood

Abstract The mode of action of phenol-formaldehyde (PF)-modified wood has been investigated with respect to its resistance to brown rot decay. The Fenton reaction is assumed to play a key role in the initial brown rot decay. Pine microveneers were modified to various weight percent gains (WPG) with low molecular weight PF and exposed to a solution containing Fenton’s reagent. The mass loss (ML) and tensile strength loss (TSL) as well as the decomposition of hydrogen peroxide within the incubation time decreased with the increasing WPG of the veneers. Incubation of untreated and PF-modified veneers in acetate buffer containing ferric ions without H2O2 revealed that the modification strongly reduces the uptake of iron by the wood cell wall. Further studies indicated that lignin promotes the decay of wood by Fenton’s reagent. The reason for the enhanced resistance of modified wood to the Fenton reaction is attributable to the impeded diffusion of iron ions into the cell wall rather than to the blocking of free phenolic sites of lignin, which accelerate redox cycling of iron.

scholarly journals Comparative Transcriptomics During Brown Rot Decay in Three Fungi Reveals Strain-Specific Degradative Strategies and Responses to Wood Acetylation

2021 ◽  
Vol 2 ◽  
Author(s):  
Martina Kölle ◽  
Maria Augusta Crivelente Horta ◽  
J. Philipp Benz ◽  
Annica Pilgård
Keyword(s):  
Oxidative Degradation ◽  
Brown Rot ◽  
Gene Clusters ◽  
Brown Rot Fungi ◽  
Platform Chemicals ◽  
Regulatory Circuits ◽  
Detection And Identification ◽  
Brown Rot Decay ◽  
Underlying Mechanisms ◽  
The Impact

Brown rot fungi degrade wood in a two-step process in which enzymatic hydrolysis is preceded by an oxidative degradation phase. While a detailed understanding of the molecular processes during brown rot decay is mandatory for being able to better protect wooden products from this type of degradation, the underlying mechanisms are still not fully understood. This is particularly true for wood that has been treated to increase its resistance against rot. In the present study, the two degradation phases were separated to study the impact of wood acetylation on the behavior of three brown rot fungi commonly used in wood durability testing. Transcriptomic data from two strains of Rhodonia placenta (FPRL280 and MAD-698) and Gloeophyllum trabeum were recorded to elucidate differences between the respective decay strategies. Clear differences were found between the two decay stages in all fungi. Moreover, strategies varied not only between species but also between the two strains of the same species. The responses to wood acetylation showed that decay is generally delayed and that parts of the process are attenuated. By hierarchical clustering, we could localize several transcription factors within gene clusters that were heavily affected by acetylation, especially in G. trabeum. The results suggest that regulatory circuits evolve rapidly and are probably the major cause behind the different decay strategies as observed even between the two strains of R. placenta. Identifying key genes in these processes can help in decay detection and identification of the fungi by biomarker selection, and also be informative for other fields, such as fiber modification by biocatalysts and the generation of biochemical platform chemicals for biorefinery applications.

scholarly journals Mode of action of brown rot decay resistance in modified wood: a review

Holzforschung ◽  
2014 ◽  
Vol 68 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Rebecka Ringman ◽  
Annica Pilgård ◽  
Christian Brischke ◽  
Klaus Richter
Keyword(s):  
Cell Wall ◽  
Mode Of Action ◽  
Wood Decay ◽  
Brown Rot ◽  
Decay Resistance ◽  
Hydroxyl Groups ◽  
Decay Fungi ◽  
Brown Rot Decay ◽  
Thermally Modified Wood ◽  
Modified Wood

Abstract Chemically or physically modified wood materials have enhanced resistance to wood decay fungi. In contrast to treatments with traditional wood preservatives, where the resistance is caused mainly by the toxicity of the chemicals added, little is known about the mode of action of nontoxic wood modification methods. This study reviews established theories related to resistance in acetylated, furfurylated, dimethylol dihydroxyethyleneurea-treated, and thermally modified wood. The main conclusion is that only one theory provides a consistent explanation for the initial inhibition of brown rot degradation in modified wood, that is, moisture exclusion via the reduction of cell wall voids. Other proposed mechanisms, such as enzyme nonrecognition, micropore blocking, and reducing the number of free hydroxyl groups, may reduce the degradation rate when cell wall water uptake is no longer impeded.

Stilbene impregnation retards brown-rot decay of Scots pine sapwood

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 261-266 ◽  
Author(s):  
Jinrong Lu ◽  
Martti Venäläinen ◽  
Riitta Julkunen-Tiitto ◽  
Anni M. Harju
Keyword(s):  
Scots Pine ◽  
Fungal Growth ◽  
Brown Rot ◽  
Monomethyl Ether ◽  
Wood Preservation ◽  
High Concentration ◽  
Brown Rot Fungi ◽  
Decay Test ◽  
Antifungal Efficiency ◽  
Brown Rot Decay

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.

scholarly journals Evidence from Serpula lacrymans that 2,5-Dimethoxyhydroquinone Is a Lignocellulolytic Agent of Divergent Brown Rot Basidiomycetes

2013 ◽  
Vol 79 (7) ◽  
pp. 2377-2383 ◽  
Author(s):  
Premsagar Korripally ◽  
Vitaliy I. Timokhin ◽  
Carl J. Houtman ◽  
Michael D. Mozuch ◽  
Kenneth E. Hammel
Keyword(s):  
Coniferous Forest ◽  
White Rot Fungi ◽  
Brown Rot ◽  
White Rot ◽  
Fenton Reagent ◽  
Fenton Chemistry ◽  
Content Type ◽  
Brown Rot Fungi ◽  
Serpula Lacrymans

ABSTRACTBasidiomycetes that cause brown rot of wood are essential biomass recyclers in coniferous forest ecosystems and a major cause of failure in wooden structures. Recent work indicates that distinct lineages of brown rot fungi have arisen independently from ligninolytic white rot ancestors via loss of lignocellulolytic enzymes. Brown rot thus proceeds without significant lignin removal, apparently beginning instead with oxidative attack on wood polymers by Fenton reagent produced when fungal hydroquinones or catechols reduce Fe3+in colonized wood. Since there is little evidence that white rot fungi produce these metabolites, one question is the extent to which independent lineages of brown rot fungi may have evolved different Fe3+reductants. Recently, the catechol variegatic acid was proposed to drive Fenton chemistry inSerpula lacrymans, a brown rot member of the Boletales (D. C. Eastwood et al., Science 333:762-765, 2011). We found no variegatic acid in wood undergoing decay byS. lacrymans. We found also that variegatic acid failed to reducein vitrothe Fe3+oxalate chelates that predominate in brown-rotting wood and that it did not drive Fenton chemistryin vitrounder physiological conditions. Instead, the decaying wood contained physiologically significant levels of 2,5-dimethoxyhydroquinone, a reductant with a demonstrated biodegradative role when wood is attacked by certain brown rot fungi in two other divergent lineages, the Gloeophyllales and Polyporales. Our results suggest that the pathway for 2,5-dimethoxyhydroquinone biosynthesis may have been present in ancestral white rot basidiomycetes but do not rule out the possibility that it appeared multiple times via convergent evolution.

Mode of action of brown rot decay resistance of thermally modified wood: resistance to Fenton’s reagent

Holzforschung ◽  
2016 ◽  
Vol 70 (7) ◽  
pp. 691-697 ◽  
Author(s):  
Reza Hosseinpourpia ◽  
Carsten Mai
Keyword(s):  
Cell Wall ◽  
Brown Rot ◽  
Strength Loss ◽  
Decay Resistance ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Brown Rot Fungi ◽  
Brown Rot Decay ◽  
Wood Resistance ◽  
Fe Ions

Abstract The resistance of heat treated (HT) wood to brown rot fungi has been investigated, while the role of the Fenton reaction (FR) in the initial phase of degradation was in focus. Micro-veneers made of Scots pine, were HT with various intensities and their mass losses (MLHT) were determined before soaking with a solution of Fenton’s reagent containing Fe ions and hydrogen peroxide. The mass loss of the veneers treated that way (MLFT), their tensile strength loss (TSLFT) and the H2O2 decomposition were observed. The MLFT, TSLFT, and H2O2 loss decreased with increasing MLHT of the veneers. Soaking of the veneers in acetate buffer containing only Fe without H2O2 revealed that the heat treatment (HT) strongly reduces the Fe uptake by the cell walls. FTIR spectroscopy indicated oxidation of the unmodified control veneers but did not reveal predominant decay of cell wall components; the HT veneers were not changed at all due to FR. It was concluded that the reason for the enhanced resistance of HT wood to FR is attributable to hindered diffusion of Fe ions into the wood cell wall.

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