White-rot Fungus Trametes Versicolor Research Articles

Gama-aminopropiltrietoksisilan ile Modifiye Edilmiş Kayın ve Göknarın Fiziksel, Mekanik ve Biyolojik Özellikleri

Silanes have potential for modifying wood materials to improving their properties. The aim of this study was to determine the physical and mechanical properties of beech (Fagus orientalis Lipsky) and fir (Abies bornmülleriana Mattf.) wood samples impregnated with gamma-aminopropyltriethoxysilane (APTES) as well as their performance against decay fungi. Beech and fir wood samples were impregnated with APTES at 20% and 40% concentrations. Control and treated samples were subjected to water uptake, bending strength and thermogravimetric analysis (TGA) tests as well as exposure to the white-rot fungus Trametes versicolor and the brown-rot fungus Coniophora puteana. Weight percentage gain (WPG) was higher in fir samples than in beech samples after APTES treatment. Water uptake was higher in fir samples than beech for control and impregnated samples. Water uptake decreased with higher APTES concentrations. APTES treatment slightly increased modulus of rupture (MOR) and modulus of elasticity (MOE). Mass loss caused by decay fungi was much lower in APTES treated timbers.

Aerobic H2 production related to formate metabolism in white-rot fungi.

Biohydrogen is mainly produced by anaerobic bacteria, anaerobic fungi, and algae under anaerobic conditions. In higher eukaryotes, it is thought that molecular hydrogen (H2) functions as a signaling molecule for physiological processes such as stress responses. Here, it is demonstrated that white-rot fungi produce H2 during wood decay. The white-rot fungus Trametes versicolor produces H2 from wood under aerobic conditions, and H2 production is completely suppressed under hypoxic conditions. Additionally, oxalate and formate supplementation of the wood culture increased the level of H2 evolution. RNA-seq analyses revealed that T. versicolor oxalate production from the TCA/glyoxylate cycle was down-regulated, and conversely, genes encoding oxalate and formate metabolism enzymes were up-regulated. Although the involvement in H2 production of a gene annotated as an iron hydrogenase was uncertain, the results of organic acid supplementation, gene expression, and self-recombination experiments strongly suggest that formate metabolism plays a role in the mechanism of H2 production by this fungus. It is expected that this novel finding of aerobic H2 production from wood biomass by a white-rot fungus will open new fields in biohydrogen research.

Treatability Changes of Radiata Pine Heartwood Induced by White-Rot Fungus Trametes versicolor

Desired retention and depth into wood are necessary for wood preservatives to provide long-term durability. In general, heartwood of wood is difficult to treat, and bioincising was investigated as a potential technique to improve the treatability of refractory wood and heartwood. In order to study the effects of bioincising treatment with white-rot fungus Trametes versicolor on the pore structure and treatability of radiata pine heartwood, this research conducted tests of mass loss, microscopic structures, pore structure parameters, uptake, and penetration of preservative of radiata pine heartwood specimens incubated by T. versicolor for 4, 8, and 12 weeks. The results showed that the optimal inoculation time of T. versicolor bioincising on radiata pine heartwood was 4 to 8 weeks. At this time, the retention of injected preservatives increased by 5.01%–17.73%, the penetration depth of preservatives increased significantly, and the corresponding mass loss was 3.04%–6.45%. The results of microstructure and pore structure showed that T. versicolor entered the adjacent tracheids via apertures, with less impact on the cell wall, mainly degrading pit membranes and ray parenchyma cells early in the inoculation of radiata pine heartwood. As the structures impeding fluid flow were connected, the porosity of the wood and the range of the main pore size distribution increased significantly, thus increasing the treatability of radiata pine heartwood.

Wood Degradation by Fomitiporia mediterranea M. Fischer: Exploring Fungal Adaptation Using Metabolomic Networking

Fomitiporia mediterranea M. Fischer (Fmed) is a white-rot wood-decaying fungus associated with one of the most important and challenging diseases in vineyards: Esca. To relieve microbial degradation, woody plants, including Vitis vinifera, use structural and chemical weapons. Lignin is the most recalcitrant of the wood cell wall structural compounds and contributes to wood durability. Extractives are constitutive or de novo synthesized specialized metabolites that are not covalently bound to wood cell walls and are often associated with antimicrobial properties. Fmed is able to mineralize lignin and detoxify toxic wood extractives, thanks to enzymes such as laccases and peroxidases. Grapevine wood's chemical composition could be involved in Fmed's adaptation to its substrate. This study aimed at deciphering if Fmed uses specific mechanisms to degrade grapevine wood structure and extractives. Three different wood species, grapevine, beech, and oak. were exposed to fungal degradation by two Fmed strains. The well-studied white-rot fungus Trametes versicolor (Tver) was used as a comparison model. A simultaneous degradation pattern was shown for Fmed in the three degraded wood species. Wood mass loss after 7 months for the two fungal species was the highest with low-density oak wood. For the latter wood species, radical differences in initial wood density were observed. No differences between grapevine or beech wood degradation rates were observed after degradation by Fmed or by Tver. Contrary to the Tver secretome, one manganese peroxidase isoform (MnP2l, jgi protein ID 145801) was the most abundant in the Fmed secretome on grapevine wood only. Non-targeted metabolomic analysis was conducted on wood and mycelium samples, using metabolomic networking and public databases (GNPS, MS-DIAL) for metabolite annotations. Chemical differences between non-degraded and degraded woods, and between mycelia grown on different wood species, are discussed. This study highlights Fmed physiological, proteomic and metabolomic traits during wood degradation and thus contributes to a better understanding of its wood degradation mechanisms.

Changes in chemical composition, crystallinity, and microstructure of wood fiber mat-reinforced composite caused by white-rot fungus Trametes versicolor and brown-rot fungus Gloeophyllum trabeum

ABSTRACT Wood fiber mat-reinforced composite (WFMRC) is a novel type of engineering wood-based polymer composite for decorative and building applications. Fungal decay strongly influences the service life of wood composites in outdoor environments. In this study, fungal durability tests were conducted to investigate how white- and brown-rot fungi (Trametes versicolor and Gloeophyllum trabeum, respectively) affect the chemical composition, crystallinity, and morphology of WFMRCs made from two different wood species (poplar and larch). The poplar WFMRC lost more mass (18.3% and 18.4% by T. versicolor and G. trabeum, respectively) than the decayed larch WFMRC (11.4% and 18.4% by T. versicolor and G. trabeum, respectively) after 12 weeks of fungal exposure. Chemical analysis and Fourier-transform infrared spectroscopy measurement revealed the degradation of holocellulose of the WFMRCs after fungal decay. X-ray diffraction analyses demonstrated that fungal decay increased the crystallinity of the poplar WFMRC but decreased the crystallinity of the larch WFMRC. Bore hole formation on the walls of wood cells, cell wall thinning, and collapsed cells were found in decayed samples, particularly in the poplar WFMRC. Although the WFMRCs could be classified as resistant to fungal decay, an appropriate protective measure should be considered to improve the outdoor durability of the WFMRC.

Changes in Chemical Structure of Thermally Modified Spruce Wood Due to Decaying Fungi.

Fungi play a critical role in the decomposition of wood and wood-based products in use. The ability of decaying fungi to cause degradation of polysaccharides and lignin in the thermally modified Norway spruce (Picea abies L. Karst.) wood was examined with pure culture decomposition tests in laboratory conditions using the brown-rot fungus Serpula lacrymans (Schumacher ex Fries) S.F. Gray and white-rot fungus Trametes versicolor (Linnaeus ex Fries) Pilat. Spruce wood samples were primary thermally treated under atmospheric pressure at the temperatures of 100, 150, 200, 220, 240 and 260 °C during 1, 3 and 5 h, whereby larger losses in their mass, holocellulose, mannose and xylose were achieved at harder thermal regimes. Meanwhile, the holocellulose percent content reduced considerably, and the percent content of lignin increased sharply. Spruce wood thermally modified at and above 200 °C better resisted to brown-rot fungus S. lacrymans than the white-rot fungus T. versicolor. Due to the decay processes, the mass fractions of holocellulose, cellulose and hemicelluloses were lower in those spruce wood samples in which thermal degradation was more intensive, with achieving the highest mass loss values after thermal treatments, after which the decay attacks were poorer or even none with the minimal mass loss values due to action by the brown-rot fungus S. lacrymans and the white-rot fungus T. versicolor. The mannose and glucose percent content in thermally–fungally attacked spruce wood was intensive reduced, e.g., by 17% to 98% in wood after thermal treatments at temperature equal and above 200 °C.

Fatty acid secretion by the white-rot fungus, Trametes versicolor.

Fungi can acquire and store nutrients through decomposing and converting organic matter into fatty acids. This research demonstrates for the first time that the white-rot fungus Trametes versicolor has the ability to secrete extracellular droplets which can contain a high concentration of long-chain fatty acids and unsaturated fatty acids as well as monosaccharides and polysaccharides. The concentration and composition of the fatty acids varied according to the age of the droplet and the feedstock used for growth of the fungi. The results raise the possibility that these droplets could be harvested offering a new approach for the microbial generation of oil from waste.

Outdoor Wood Mats-Based Engineering Composite: Influence of Process Parameters on Decay Resistance against Wood-Degrading Fungi Trametesversicolor and Gloeophyllumtrabeum.

The process parameters significantly influence the preparation and final properties of outdoor wood mats-based engineering composite (OWMEC). During outdoor use, wood composites are susceptible to destruction by rot fungi. Herein, the role of process parameters such as density and resin content on OWMEC resistance to fungal decay was investigated. The poplar OWMEC samples were exposed to white-rot fungus Trametes versicolor and brown-rot fungus Gloeophyllum trabeum for a period of 12 weeks. The chemical composition, crystallinity, and morphology were evaluated to investigate the effect of process parameters on the chemical composition and microstructure of the decayed OWMEC. With an increase in the density and resin content, the mass loss of the decayed OWMEC decreased. The highest antifungal effect against T. versicolor (12.34% mass loss) and G. trabeum (19.43% mass loss) were observed at a density of 1.15 g/m3 and resin content of 13%. As results of the chemical composition and microstructure measurements, the resistance of OWMEC against T. versicolor and G. trabeum fungi was improved remarkably by increasing the density and resin content. The results of this study will provide a technical basis to improve the decay resistance of OWMEC in outdoor environments.

Hesperozygis ringens (Benth.) Epling essential oil: antifungal activity and effect on ergosterol content of wood-decay fungi

ABSTRACT This study aimed to evaluate the antifungal potential of the essential oil (EO) from Hesperozygis ringens leaves and its major compound pulegone against wood-decay fungi. In addition, their effect on mycelia ergosterol content was assayed. The EO was extracted by hydrodistillation and its chemical composition was analyzed by gas chromatography coupled to mass spectrometry and gas chromatography with flame ionization detector. Pulegone was isolated through column chromatography. The EO and pulegone were tested on white-rot fungi (Ganoderma applanatum and Trametes versicolor), and brown-rot fungi (Gloeophyllum trabeum and Lentinus lepideus) in five and three concentrations, respectively. Propiconazole was used as positive control. The EO inhibited T. versicolor growth while pulegone inhibited growth of both white-rot species. Pulegone presented lower half-maximal inhibitory concentration than the EO for white-rot fungi. Both EO and pulegone negatively affected white-rot fungi ergosterol contents. White-rot fungi, in general, were more susceptible to EO and pulegone.

Investigation of fungal decay of poplar wood treated with pistachio resin

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.

Glutathione Transferases: Surrogate Targets for Discovering Biologically Active Compounds.

Glutathione transferases comprise a large class of multifunctional enzymes, some involved in detoxification pathways. Since these enzymes are able to interact with potentially toxic molecules, they could be used as targets to screen for compounds with biological activity. To test this hypothesis, glutathione transferases (GSTs) from the white-rot fungus Trametes versicolor have been used to screen for antifungal molecules from a library of tropical wood extracts. The interactions between a set of six GSTs from the omega class and 116 extracts from 21 tropical species were quantified using a high-throughput thermal shift assay. A correlation between these interactions and the antifungal properties of the tested extracts was demonstrated. This approach has been extended to the fractionation of an Andira coriacea extract and led to the detection of maackiain and lapachol in this wood. Altogether, the present results supported the hypothesis that such detoxification enzymes could be used to detect biologically active molecules.

Influence of Copper and Biopolymer/Saqez Resin on the Properties of Poplar Wood

There is an increasing trend in the use of environmentally-friendly materials in wood protection. This includes the use of less toxic active ingredients, as well as better fixation. This study investigates the formulation based on the combination of copper and Saqez resin on the physical and biological resistance properties of poplar wood. Samples were treated by either copper-ethanolamine (Cu/MEA) and/or Saqez resin at various treatment levels. A vacuum pressure procedure was applied. The retention, weight percent gain, water absorption, volumetric swelling, and decay resistance of the samples were then determined. The highest retention and weight percent gain were obtained in the samples treated with the combination of copper-based system and Saqez resin. Additionally, the combination of the copper and Saqez improved the physical properties and decay-resistance against white-rot fungus Trametes versicolor.

Exploring the degradation capability of Trametes versicolor on selected hydrophobic pesticides through setting sights simultaneously on culture broth and biological matrix

Pesticides introduced inadvertently or deliberately into environment by global agricultural practices have caused growing public concern, therefore the search of approaches for elimination of such xenobiotics should be motivated. The degradation of hydrophobic pesticides including chlorpyrifos, dicofol and cypermethrin were assayed with the white-rot fungus Trametes versicolor. Experiments were set at realistic concentration as 5 μg L−1, and both culture medium and biologic matrix were analyzed for pollutants residues. Results showed that the first step was due to a fast adsorption, which also played an important role, accounting for more than 90% removal in average. Then mass balances proposal evidenced the biodegradation of the adsorbed pollutants, demonstrating efficient depletion as 94.7%, 87.9% and 93.1%, respectively. Additionally, the related degradation metabolites were identified using ultra performance liquid chromatography coupled to high resolution mass spectrometry. Two compounds, namely O,O-diethyl thiophosphate and diethyl phosphate were detected as transformation products of chlorpyrifos, whereas dicofol was degraded into benzaldehyde that is first time to be reported. It also confirms the degradation capability of T. versicolor. Our results suggest that T. versicolor is a potential microorganism for bioremediation of hydrophobic pesticide contaminated environments.

The efficiency of Pistacia atlantica gum for increasing resistance of rapeseed oil-heat treated wood to fungal attacks

In this research, we used Pistacia atlantica gum during cooling phase of oil-heat treatment of poplar wood (Populus deltoids) to improve its resistance to the white-rot fungus Trametes versicolor and growth of the mold fungus Penicillium expansum. Thermal modification was carried out using rapeseed oil at 180 °C, 200 °C and 220 °C for 2 hours and 4 hours. The modified wood specimens were then directly cooled in the oil containing 0 %, 5 % and 10 % (w/w) of the gum at 25 °C for 30 minutes. The chemical constituents of the essential oil extracted with a Clevenger type apparatus were determined by chromatography–mass spectrometry (GC-MS). The amounts of α-pinene, β-pineneand α-terpinolene of the essential oil were 60,2 %, 8,7 % and 3,9 %, respectively. The mold resistance was greatly improved, while the improvement against the decay fungus was only observed for the specimens modified at 180 °C. Our results confirmed that the enhanced fungal resistance was not only due to the presence of monoterpenes in the essential oil, but also to a further reduction in the hygroscopicity of the treated wood

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

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%.

White-Rot Fungi Control on Populus spp. Wood by Pressure Treatments with Silver Nanoparticles, Chitosan Oligomers and Propolis

There is growing interest in the development of non-toxic, natural wood preservation agents to replace conventional chemicals. In this paper, the antifungal activities of silver nanoparticles, chitosan oligomers, and propolis ethanolic extract were evaluated against white-rot fungus Trametes versicolor (L.) Lloyd, with a view to protecting Populus spp. wood. In order to create a more realistic in-service type environment, the biocidal products were assessed according to EN:113 European standard, instead of using routine in vitro antimicrobial susceptibility testing methods. Wood blocks were impregnated with the aforementioned antifungal agents by the vacuum-pressure method in an autoclave, and their biodeterioration was monitored over 16 weeks. The results showed that treatments based on silver nanoparticles, at concentrations ranging from 5 to 20 ppm, presented high antifungal activity, protecting the wood from fungal attack over time, with weight losses in the range of 8.49% to 8.94% after 16 weeks, versus 24.79% weight loss in the control (untreated) samples. This was confirmed by SEM and optical microscopy images, which showed a noticeably higher cell wall degradation in control samples than in samples treated with silver nanoparticles. On the other hand, the efficacy of the treatments based on chitosan oligomers and propolis gradually decreased over time, which would be a limiting factor for their application as wood preservatives. The nanometal-based approach is thus posed as the preferred choice for the industrial treatment of poplar wood aimed at wood-based engineering products (plywood, laminated veneer lumber, cross-laminated timber, etc.).

Rot resistance of tropical wood species affected by water leaching

Initial water leaching affects were studied relative to the rot resistance of 21 tropical wood species to the brown-rot fungus Coniophora puteana and the white-rot fungus Trametes versicolor. The rot resistance of tropical woods, determined by their weight loss (∆m) at 6-weeks fungal attack, was differently influenced by the initial water leaching, as follows: in the 1st group of eight durable species (dark red meranti, macassar ebony, cerejeira, merbau, santos rosewood, zebrano, wengé, and karri) there occurred a very significant decrease of their high rot resistance (with statistical confidence in the range 99 to 99.9% for different species); in the 2nd group of 10 durable species (ipé, yellow balau, doussié, bubinga, ovengol, padouk, iroko, blue gum, maçaranduba, and makoré) there did not occur a decrease of their high rot resistance; and in the 3rd group of three less durable species (okoumé, tineo, sapelli) a weaker rot resistance did not change due to leaching. The durable tropical woods (18 species from the 1st and 2nd groups) were more resistant to the brown-rot fungus (∆mC.p.-average = 0.72%) than the white-rot fungus (∆mT.v.-average = 1.07%). However, this phenomenon was no longer apparent after water leaching (∆mC.p.-Leached-average = 2.61%; ∆mT.v.-Leached-average = 2.32%).

Decolourization and detoxification of monoazo dyes by laccase from the white-rot fungus Trametes versicolor

The decolourization and detoxification of azo dyes (Orange 2, Acid Orange 6) by fungal laccase from Trametes versicolor were evaluated. For laccase catalysed reaction, the azonaphthol Orange 2, with 72.8% decolourization, was degraded more rapidly than the azobenzene Acid Orange 6, with 45.3%. The presence of hydroxyl group at o-position to azo bond in the structure of Orange 2 was more preferable than the presence of two hydroxyl groups at o- and p-positions to azo bond in Acid Orange 6. Although the laccase treatment was more effective for the Orange 2 decolourization, the toxicity of both monoazo dye solutions became less toxic for the prokaryote growth. The phytotoxicity of Orange 2 and Acid Orange 6 solutions after laccase treatment was decreased in the range of 41.2–64.3 %. Also, the photoxicity, as measured by the production of chlorophylls a and b by Chlorella vulgaris and Microcystis aeruginosa, was decreased by laccase treatment of selected monoazo dyes. Our results show that different dyes can be decolorized and detoxified by laccase from T. versicolor in a single step.

Removal of phenols-like substances in pharmaceutical wastewater with fungal bioreactors by adding Trametes versicolor.

Fungi are known to be more resistant to toxic compounds and more effective in removing recalcitrant organics such as phenols than bacteria. Here we examined the removal of phenols (as a component of Zopliclone drugs), added to non-sterile pharmaceutical wastewater with continuous treatment fungal bioreactor by its augmentation with mono-species of white-rot fungi (WRF) Trametes versicolor. Results showed that WRF in a sterile reactor (a batch mode) were moderately effective for removal of phenols (40% in seven days); however, native wastewater microbes at optimal conditions for fungi (pH 5.5, 25 °C) were more effective (90%, both in batch and continuous flow modes). In continuous flow mode, addition of WRF was an effective way to mitigate high loads of phenols (up to 400 mg/L), by both fungal enzymes (growth rate 0.075 h-1, laccase enzymatic activity 4 nkat/mL) and biosorption. The study confirmed that naturaly occuring fungi in combination with fungus-augmentation is an effective approach for treatment of high-strength pharmaceutical wastewater.

Biodegradation of diuron in artificially contaminated water and seawater by wood colonized with the white-rot fungus Trametes versicolor

We investigated the potential of white-rot fungi for bioremediation of aqueous environments contaminated with diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea). First, diuron degradation activities of several white-rot fungi (Ceriporia lacerata, Phanerochaete chrysosporium, Phanerochaete sordida, Trametes versicolor) and a brown-rot fungus (Gloeophyllum trabeum) were evaluated under low- or high-nitrogen conditions. While G. trabeum showed hardly any degradation activity, white-rot fungi except for C. lacerata showed degradation activity, at least under some conditions. In particular, the activity of T. versicolor was high regardless of culture conditions (30–35% degradation at both levels of nitrogen). T. versicolor degraded diuron to two metabolites, 1-(3,4-dichlorophenyl)-3-methylurea and 1-(3,4-dichlorophenyl)urea, and did not accumulate the highly toxic metabolite 3,4-dichloroaniline. Moreover, the diuron content of artificially contaminated water dramatically decreased from 1.0 to 0.012 µM and artificially contaminated seawater (3.4% sea salt, w/v) decreased to 0.405 µM after incubation for 2 weeks with shaking on T. versicolor-colonized wood medium. These results indicated that wood medium colonized with white-rot fungi may be applicable for bioremediation and detoxification of diuron-contaminated aqueous environments.