Wood Biodegradation Research Articles

An Experimental Validated Computational Method for pKa Determination of Substituted 1,2-Dihydroxybenzenes

1,2-dihydroxybenzenes (DHBs) are organic compounds which are widely studied as they are applied to advanced oxidation processes (AOPs). These compounds are also related to the development of oxidative stress, wood biodegradation, and neuronal disease in humans. DHBs are metal ligands with pro-oxidant and antioxidant properties. These activities are related to their chelation properties and a consequence of the deprotonation of their hydroxyl groups. In literature, there are several pKa values for the hydroxyl groups of DHBs. These values vary depending on the experimental conditions or the algorithm used for calculation. In this work, an experimentally validated computational method was implemented in aqueous solution for pKa determination of 24 DHBs. The deprotonation order of the hydroxyl groups in DHB was determined observing a selective deprotonation, which depended on the ability of the substituent to donate or withdraw electron density over the ring.

Investigating the effect of white-rot hymenomycetes biodegradation on basal stem rot infected oil palm wood blocks: Biochemical and anatomical characterization

Basal Stem rot (BSR) disease of oil palm caused by Ganoderma boninense is one of the major obstacle in oil palm production. The root contact with unattended infected debris left in the plantations during replanting is known to be the primary source of infection spread. Abiding with the law, potentially effective technique of managing Ganoderma infected oil palm debris is deemed necessary because of the zero-burning policy in Malaysian oil palm plantations. The wood degradation abilities of four white-rot hymenomycetes were assessed using oil palm blocks obtained from healthy and diseased portions of oil palm trunks infected with G. boninense. In general, out of four white-rot hymenomycetes, Pycnoporus sanguineus FBR secreted a significantly (P≤0.05) greater quantity of oxidative enzymes than that secreted by the Grammothele fuligo strains. The ability of G. fuligo ST2 and P. sanguineus FBR to secrete amylase enzymes has been well documented and the enzyme profiles were about 4.5-fold (G. fuligo ST2) and 2.8-fold (P. sanguineus FBR) higher in samples collected at day 120 than at day 30 of biodegradation, supported with Fourier transform infrared (FTIR) spectra. The crystallinity ratio was found to increase in the middle of decay process, owing to the preferential degradation of non-crystalline lignins and hemicelluloses by both strains. Syringyl (S)-lignin units were favorably degraded than guaiacyl (G)-lignin units by both strains, resulting in a decreased S/G ratio in the diseased portions, at the end of decay process. Scanning electron microscopy (SEM) revealed that penetration of fungal hyphae within the wood vessels and the parenchymal tissues with boreholes, resulting in the loosening of the parenchymal tissue and wood rays. Based on the lignocellulolytic enzymes production and the level of degradation, P. sanguineus FBR and G. fuligo ST2 regarded as the best bio-degraders of G. boninense colonized wood blocks. This study provides the novel insight on understanding the biochemical and anatomical changes induced by white-rot hymenomycetes during biodegradation of oil palm wood blocks with an ultimate aim of reducing the Ganoderma inoculum under heavy BSR infection pressure in ecofriendly manner.

Antifungal activity of several essential oils and major components against wood-rot fungi

Biodegradation of wood by fungi is recognized as one of the most serious problems for wooden structures and forest management. This study evaluated the fungicidal activity of 6 plant essential oils (Origanum vulgare, Cymbopogon citratus, Thymus vulgaris, Pelargonium graveolens, Cinnamomum zeylanicum and Eugenia caryophyllata) against the wood-rot fungi, Trametes hirsuta and Laetiporus sulphureus.Results from antifungal tests revealed that six essential oils showed good antifungal activities, in which, O. vulgare was the most toxic to the wood-rot fungi, with the IC50 values against T. hirsuta and L. sulphureus of 79.1 and 36.9μg/mL, respectively. The composition of six essential oils was indentified by using gas chromatographic-mass spectrometry. The six major compounds from 6 essential oils were tested individually for their fungicidal activities against two wood-rot fungi.Results from the antifungal tests demonstrated that the six major compounds exhibited strong fungicidal activity. In addition, carvacrol was the most toxic against the wood-rot fungi, with the IC50 values against T. hirsuta and L. sulphureus of 33.6 and 17.2μg/mL, respectively. Furthermore, phenol and aldehyde groups were more toxic than alcohol. The results show that the six plant essential oils and their major chemical constituents have potential for the development of natural wood preservatives.

Whole-cell biosensor of cellobiose and application to wood decay detection

Fungal biodegradation of wood is one of the main threats regarding its use as a material. So far, the detection of this decaying process is empirically assessed by loss of mass, when the fungal attack is advanced and woody structure already damaged. Being able to detect fungal attack on wood in earlier steps is thus of special interest for the wood economy. In this aim, we designed here a new diagnostic tool for wood degradation detection based on the bacterial whole-cell biosensor technology. It was designed in diverting the soil bacteria Streptomyces CebR sensor system devoted to cellobiose detection, a cellulolytic degradation by-product emitted by lignolytic fungi since the onset of wood decaying process. The conserved regulation scheme of the CebR system among Streptomyces allowed constructing a molecular tool easily transferable in different strains or species and enabling the screen for optimal host strains for cellobiose detection. Assays are performed in microplates using one-day culture lysates. Diagnostic is performed within one hour by a spectrophotometric measuring of the cathecol deshydrogenase activity. The selected biosensor was able to detect specifically cellobiose at concentrations similar to those measured in decaying wood and in a spruce leachate attacked by a lignolytic fungus, indicating a high potential of applicability to detect ongoing wood decay process.

Impact of enzymatic treatment on wood surface free energy: contact angle analysis

The aim of this study was to investigate the effect of cellulase treatment on wood surface physicochemical characteristics. The cedar wood samples were treated by cellulase for 30 min at different concentrations: 0.2, 0.4, 0.6, 0.8, 1, and 1.2 mg/ml. Then the physicochemical properties (the wetting behavior and interfacial free energy) of the cedar samples surfaces were characterized by the sessile drop technique. The obtained results showed that the untreated cedar wood samples exhibited a hydrophobic character with a high water contact angle (θw = 71.9°) and a negative value of the interfacial free energy (∆Giwi = −59.3 mJ/m2). Thereafter, the wood hydrophobicity decreased continuously until it reached the hydrophilicity qualitatively (at the first concentration of cellulase (0.2 mg/ml)) and quantitatively (at 0.8 mg/ml of cellulase). The cedar wood surface treatment with cellulase also revealed a significant evolution of the acid-base parameters. Moreover, a linear relationship between the degree of hydrophobicity and the cellulase concentration has been found. This study clearly shows the impact that could have the produced enzyme by micro-organisms involved in wood biodegradation and especially their consequences on the physicochemical surface properties of the wooden materials.

TRANSLOCATION OF TRANSITION METALS DURING THE DEGRADATION OF PINUS RADIATA BY GLOEOPHYLLUM TRABEUM ON THE FOREST SOIL

Brown rot fungi (BRF) are highly destructive wood degraders characterized by extensive degradation and mineralization of cellulose and hemicellulose, in most of the cases without causing a substantial removal of lignin. BRF have not a complete cellulase complex neither ligninolytic enzymes, therefore, has been hypothesized that to degrade wood components, a non-enzymatic mechanism based on ●OH radicals production through Fenton reaction is also involved. The availability of iron limits the Fenton reaction in wood biodegradation by BRF, because this metal (and other transition metals) is found in small amounts in wood. For this reason, it has been postulated that the fungus transport metals from the soil. To study the effect of soil and transition metal translocation (Fe, Cu, and Mn) on wood biodegradation by the BRF Gloeophyllum trabeum , Pinus radiata wood chips (20 years old) were incubated with forest soil in stationary tray bioreactor for a period until 16 weeks. Translocation of transition metals, mass and wood components (extractives, carbohydrates, and lignin) loss, the decrease of holocellulose viscosity and oxalic acid production were determined at different intervals of time. Wood on soil showed a high translocation of transition metals mainly Fe. Translocation of soil metals into the wood was relevant for improving fungal growth and wood decay, which is correlated significantly with higher loss mass and wood components compared with degradation without soil.

Antifungal activity of monoterpenes against wood white-rot fungi

Biodegradation of wood by fungi is a chronic problem for wood utilization. Natural products from plants have great potential as novel fungicide sources for controlling wood decay fungi as alternative to synthetic pesticides. Many plant extracts and essential oils contain monoterpenes, sesquiterpenes and aliphatic compounds. In the present study, 41 pure monoterpenes were tested for the toxicity against wood white-rot fungi, Trametes hirsuta, Schizphylhls commune, and Pycnoporus sanguineus. Results from antifungal tests revealed that β-citronellol, geraniol, carvacrol, thymol, eugenol and citral showed good antifungal activities against the three tested fungi. In addition, the carvacrol was the most toxic monoterpenes against the three tested fungi, the IC50 values against T. hirsuta, S. commune and P. sanguineus were 87.6, 53.6 and 71.7 μg ml−1, respectively. The present results indicated that carvacrol have potential to be developed as natural fungicidal agents, suggesting that further study of wood preservation treatment be warranted.

Antitermitic and antifungal activities of eugenol and its congeners from the flower buds of Syzgium aromaticum (clove)

Biodegradation of wood by fungi and termites is recognized as one of the most serious problems for wooden structures. In this study, we analyzed the antitermitic and antifungal activities of flower buds essential oil from Syzygium aromaticum and its dominant constituents. Essential oil components were analyzed by gas chromatography and the major compound of essential oil was eugenol (90.6%). The results demonstrated that at the dosage of 50μg/g, clove essential oil had 100% mortality to Reticulitermes chinensis after testing for 5 d. Furthermore, we found eugenol killed all termites after testing for 3 d, with an LC50 value of 12.1μg/g. Meanwhile, we also found clove essential oil and eugenol displayed activity against three fungi, Trametes hirsuta, Schizphylhls commne, and Pycnoporus sanguineus. We found eugenol was principal antifungal constituent of clove oil. The IC50 values of eugenol against T. hirsuta, S. commne, and P. sanguineus were 83.6, 116.1, and 102.4μg/mL, respectively. In addition, comparisons of the termite mortality and antifungal indices of eugenol and its congeners proved that eugenol exhibited the strongest antitermitic and antifungal activities. The clove oil and eugenol have potential for the development of natural wood preservatives.

伝統的木構造物で使用される銅金物の劣化抑制への寄与（第Ⅰ報）－京都三条大橋欄干の蛍光X 線分析－

伝統的木構造物で使用される銅金物の劣化抑制への寄与（第Ⅰ報）－京都三条大橋欄干の蛍光X 線分析－

Biodegradation of wood exposed in the marine environment: Evaluation of the hazard posed by marine wood-borers in fifteen European sites

The activity of marine wood-borers causes great destruction in maritime wooden structures. Therefore, the aim of this study was to evaluate the hazard posed by marine wood-borers in fifteen European sites, to assist authorities and researchers concerned with the protection of wood in the sea. In northern Europe, Teredo navalis is the species that poses the highest borer hazard while in the Atlantic coast of southern Europe Lyrodus pedicellatus is the most destructive species, with the exception of two sites in Portugal. In these sites, Limnoria tripunctata was more destructive than L. pedicellatus. In the Mediterranean both T. navalis and L. pedicellatus pose a very high borer hazard to wooden structures.Salinity and temperature emerged as the environmental conditions that best explain the occurrence and abundance of wood boring species in the sites surveyed. Three of the species highlighted in this study are warm water species. Therefore their activity might increase in the future, due to global warming. Considering that wood is still a very valuable material for construction, its use for maritime construction should be favoured. Thus research to improve the durability of wooden materials in the marine environment is of paramount importance.

Diversity of decay resistance strategies of durable tropical woods species: Bocoa prouacencsis Aublet, Vouacapoua americana Aublet, Inga alba (Sw.) Wild

The study of decay resistance in wood is of interest for wood end-users but also for the global carbon balance since wood biodegradation is a key driver of forest ecosystem functioning through its impacts on carbon and nutrient cycling. We studied the density and wood extractive contents in order to understand decay resistance against soil microflora after 90 days exposure of sapwood and heartwood from three Neotropical wood species known for their decay resistance: Bocoa prouacensis, Vouacapoua americana, Inga alba. Decay resistance was correlated with density more than wood extractive content. The results highlighted different decay resistance strategies. In B. prouacensis, both sapwood and heartwood were highly resistant due to the high density and high content of antifungal wood extractives. In V. americana heartwood, decay resistance was due to the high synergistic-acting wood extractive content. Conversely, with the least dense wood species I. alba, we found that decay resistance was due to the antifungal wood extractives synthesized early in the sapwood. In conclusion, we showed that the three wood species with the same level of heartwood decay resistance performance had different decay resistance strategies according to the anatomic and defensive wood traits.

Biodegradation of eucalyptus urograndis wood by fungi

We focused in selecting four fungi, naturally living in Eucalyptus sp. fields, for application in accelerating stump decay. The wood-rot fungi Pycnoporus sanguineus (Ps), Lentinus bertieri (Lb) and Xylaria sp. (Xa) were isolated from Eucalyptus sp. field and the fungus Lentinula edodes (Led) was obtained from a commercial strain. All fungi were studied according to their capacity to degrade eucalyptus urograndis wood. In order to evaluate mass losses of seven years old eucalyptus urograndis' wood test blocks from heartwood were prepared added to glass flasks with red clay soil. The humidity of the soil was adjusted with 50 and 100% of its water retention capacity. Mass loss evaluations occurred at 30 until 120 days after eucalyptus wood degradation. Chemical analysis and soil pH were measured only in the last evaluation. Mycelial growth assays with potato-dextrose-agar, malt-agar and sawdust-dextrose-agar at three temperatures was carried out in order to get information about the best conditions of fungi growth. On the 120th day, Ps and Lb showed good capacity of wood degradation by leading to a high mass loss in soil with highest humidity. These fungi were the best consumers of lignin, hemicellulose, cellulose and extractives, caused acidification in the soil. Ps and Lb had faster mycelial growth in sawdust-dextrose-agar, especially in high temperature, comparing to Xa and Led. Xa and Led are not good eucalyptus urograndis heartwood degraders, because they consume preferentially hemicellulose.

FENTON REACTION DRIVEN BY IRON LIGANDS

ABSTRACT One of the most important sources of reactive oxygen species (ROS) in biological systems is the Fenton reaction. In this, the Fe 2+ or Fe 3+ reacts with H 2 O 2 to produce ROS as the hydroxyl radical (∙OH), superoxide radical (O 2∙- ) and singlet oxygen ( 1 O 2 ).The main ROS, responsible for the high oxidizing power of the Fenton reaction, is not clear. Some authors claim that the principal reactive species is ∙OH, while others propose a ferryl specie (Fe 4+ or [FeO] 2+ ) ( 1, 2 ) . Recently, have been proposed that the kind of reaction species produced depends mainly of pH and the iron composition of the coordination sphere. This is highlighted for Fe 3+ , because in mono and (some) bis-complexes Fe is reduced to Fe 2+ and there are some positions occupied by water or hydroxide ligands, readily to be exchanged by H 2 O 2 . On the other hand, in tris-complexes there are not any positions occupied by water or hydroxide, avoiding the formation of peroxo-complexes, necessary for Fenton or Fenton like reaction.The 1,2-dihydroxybenzenes (DHBs) have been described as modulators of Fenton reaction. The DHBs driven Fenton reaction have been used for environmental applications as an advanced oxidation process. Furthermore, these systems participate in different biological process, as the wood biodegradation by fungi and oxidative stress in neurodegenerative diseases.In this review, the effect of 1,2-dihydroxybenzenes on the activated species production by the Fenton and Fenton like reaction will be discussed and its participation in different systems.

Density mapping of decaying wood using X-ray computed tomography

Wood biodegradation is a central process at the crossroads of several disciplines. It is not only important for carbon storage in forests, but it is also important for wood conservation, wood protection and wood transformation products. Many methods already exist for studying wood biodegradation; however, they present several drawbacks, being time-consuming or destructive. Moreover, they provide little information regarding the complexity of the degradation process and the heterogeneity of the wood substrate. Based on a kinetic study of the biodegradation of Fagus sylvatica by the white-rot fungus Phanerochaete chrysosporium, we developed an X-ray computed tomography method coupled with an in-house plugin for fast, non-destructive and accurate measurement of the density variations of decaying wood. This method allowed us to examine the spatial heterogeneity of woody decayed material at the millimeter scale, providing information about the fungal pattern of degradation. Thus, X-ray computed tomography is an efficient tool that can be used for measuring the degradation of a variety of wood substrates ranging from small normalized wood blocks to fallen logs in the forest.

Evaluation of termiticidal activity of coconut shell oil and its comparison to commercial wood preservatives

Among several factors leading to biodegradation of wood, termites are one of the most damaging agents to wooden structures worldwide. To avoid environmental pollution and health problems caused by the use of synthetic pesticides, wood preservation research is currently focusing on discovery and application of termiticides derived from plants. This paper reports and discusses the use of coconut shell oil (CSO) as a potential termiticide. Termiticidal activity of CSO was assessed and compared to wood preservatives currently in use. After 18 months of field trial, all the control stakes were destroyed completely and there was damage of 34.2 % in the CSO brush coated stakes. CSO is a promising new biodegradable compound which can be utilized for the development of a termiticide of biological origin.

In-vitro studies on wood degradation in soil by soft-rot fungi: Aspergillus niger and Penicillium chrysogenum

This paper focuses on the biodegradation of wood by two soft-rot fungi, Aspergillus niger and Penicillium chrysogenum, in soil which was artificially infested. The structural changes of pine and sycamore wood were evaluated by scanning electron microscope (SEM). Surprisingly, soft-rot fungi tolerate low moisture to cause extensive decay in the wood samples. The micrographs showed differences in hyphae colonization and wood degradation patterns between soft-rot species under this study; A. niger produced soft-rot decay type I (cavity formation) and soft-rot decay type II (erosion), while P. chrysogenum caused only soft-rot decay type II.

Fungal biodegradation of CCA-treated wood and removal of its metal components

In the present study, 5 isolates of brown-rot fungi were used for fungal bioprocessing (FB) of chromated copper arsenate (CCA)-treated wood wastes: Antrodia vaillantii SEL8501, Fomitopsis palustris TYP0507 and TYP6137, and Crustoderma sp. KUC8065 and KUC8611. The isolates showed notable capacity for the degradation of treated wood and removal of CCA components via the American Wood Protection Association soil block test. Among them, Crustoderma sp. KUC8611 effectively decayed the treated wood, causing a mass loss of up to 60%. F. palustris caused extensive leaching of CrO3 of up to 79% and As2O5 of up to 87%, but only moderate leaching of CuO of up to 50%. This high capacity for removal of CrO3 and As2O5 showed a strong logarithmic relationship with the amount of oxalic acid produced in the decayed wood. The majority of metals removed from treated wood during the decay process were deposited in the soil and feeder strip. Further investigation will be required to establish the capability of selected fungi for FB of full-sized lumber treated with CCA.

Lignin--Designed Randomness

0 0 1 282 1608 Biologic Institute 13 3 1887 14.0 Normal 0 false false false EN-US ZH-CN X-NONE Humans have long used wood as a structural material for some of the same reasons that trees use it—it combines great strength, flexibility and durability with a relatively low density. These desirable properties depend partly on lignin , a major chemical constituent of many plants, including trees. Lignin is the most abundant aromatic polymer on earth and the second most abundant organic polymer of any kind, exceeded only by cellulose. It is estimated that 30% of the earth’s non-fossil organic carbon is in the form of lignin. Considering its massive abundance and its high energy content (40% higher than cellulose, gram for gram), it is striking that no organism seems to have tapped it as an energy source. After posing this as an evolutionary enigma, we prepare to address it by reviewing what is known about the structure, biosynthesis and biodegradation of wood in general and of lignin in particular. Then, returning to the enigma, we ask whether it is more readily explained within a Darwinian framework or a design framework. The Darwinian account must somehow reconcile 400 million years of failure to evolve a relatively modest innovation—growth on lignin—with a long list of spectacular innovations thought to have evolved in a fraction of that time. How can one mechanism have been at the same time so effective and so ineffective? That tension vanishes completely when the design perspective is adopted. Terrestrial animal life is crucially dependent on terrestrial plant life, which is crucially dependent on soil, which is crucially dependent on the gradual photo- and biodegradation of lignin. Fungi accomplish th e bio degradation, and the surprising fact that it costs them energy to do so keeps the process gradual. The peculiar properties of lignin therefore make perfect sense when seen as part of a coherent design for the entire ecosystem of our planet.

Uso de aditivos na biodegradação de madeira pelo fungo Ceriporiopsis subvermispora: efeito na peroxidação de lipídios dependente de manganês-peroxidase

Ceriporiopsis subvermispora is a selective fungus in the wood delignification and the most promising in biopulping. Through the lipid peroxidation initiated by manganese peroxidase (MnP), free radicals can be generated, which can act in the degradation of lignin nonphenolic structures. This work evaluated the prooxidant activity (based in lipid peroxidation) of enzymatic extracts from wood biodegradation by this fungus in cultures containing exogenous calcium, oxalic acid or soybean oil. It was observed that MnP significant activity is required to promote lipid peroxidation and wood delignification. Positive correlation between prooxidant activity x MnP was observed up to 300 IU kg-1 of wood.

Coprinopsis cinerea

Coprinopsis cinerea