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Using heat treatment for wood protection has been driven to maturity, but the role of heat-treated wood extracts in decay resistance has lacked attention. To assess the potential of heat-treated wood extract for wood preservation, the antifungal activity of the extract against wood decay fungi and the effects of the extract on fungal wood degrading enzyme activity and cell membrane integrity were tested. Small shavings generated during the processing of larch (Larix gmelinii (Rupr.) Kuzen) were heat-treated and extracted. The antifungal activity of extract against wood decay fungi and decay resistance of extract impregnated wood were tested to assess their potential. The effect of extracts on the enzyme activity of the white-rot fungus, Trametes versicolor (L.) Lloyd and the brown-rot fungus, Gloeophyllum trabeum (Pers.: Fr.) Murr. for wood degradation was assessed by detecting the activity of cellulose, hemicellulose, and ligninase of fungi incubated with extract. The effect of extracts on the integrity of cell membranes of fungi was assessed by staining with propidium iodide (PI) and the leakage detection of nucleic acid and protein in fungi after exposure to extract. The toxicity to freshwater luminescent bacteria (Vibrio qinghaiensis sp. -Q67) and mouse macrophages (RAW264.7) of the extract impregnated wood leachate was tested and compared with the leachate of the raw wood. The results denoted that the decay resistance of poplar (Populus tomentosa Carr.) wood could be improved by heat-treated larch wood extract, and the effect of the extract impregnated wood leachate on Q67 and RAW264.7 was the same as that of raw wood leachate. The extract inhibited ligninase activity (only for T. versicolor), cellulase activity, and respiratory metabolism of tested fungi, and impaired the membrane integrity. The study identified a potential wood preservative. [Display omitted] • Heat-treated wood extract improved the decay resistance of impregnated wood. • Extract disrupts cell membrane integrity of wood decay fungi. • Extract inhibits the activity of fungal wood degrading enzymes. • The use of heat-treated wood extract utilizes the wood processing by-products. [ABSTRACT FROM AUTHOR]

Wood serves as a renewable resource; however, its sustainability is threatened by wood-rotting fungi, a type of filamentous fungi. Although its decay mechanism has been widely investigated, essential factors controlling fungal responses are poorly understood owing to the complex wood architecture mainly formed by cellulose microfibrils, hemicellulose, and lignin. This study aimed to explore the effects of wood structure and chemical components on wood-rotting fungi using chemically simplified wood substrates. Cellulose-based substrates were successfully prepared from wood sections of Cryptomeria japonica by removing non-cellulosic components while maintaining the inherent wood structure. Confocal microscopy analysis combined with Hough transformation after decay tests revealed a clear tendency of hyphae to elongate along tracheids on cellulosic substrates with wood structures. Furthermore, scanning electron microscopy demonstrated that hyphae passed through bordered pits without completely destroying the pit structure. These results indicate that wood structure is the dominant factor in hyphal responses and that the physical forces of tip growth and enzymatic degradation of components contribute simultaneously to fungal invasion in wood. This study demonstrates the usefulness of single-component substrates with preserved wood structures as new evaluation materials for studying wood-rotting, potentially facilitating research on decay for wood preservation. • The effects of wood structure and chemical components on wood-rotting fungi were studied. • Cellulosic substrates with wood anatomical features were successfully prepared. • Structured hyphal elongation was observed on the cellulosic substrates. • Hyphae passed through bordered pits without completely destroying the pit structure. • Physical substrate structure plays a crucial role in hyphal response during the invasion process. [ABSTRACT FROM AUTHOR]

Heat treatment increases the decay resistance of wood by decreasing its hygroscopicity, but the wood material remains degradable by fungi. This study investigated the degradation of heat-treated wood by brown rot fungi, with the aim of identifying fungal-induced hygroscopicity changes that facilitate degradation. Scots pine sapwood samples were modified under superheated steam at 200 and 230 °C and then exposed to Coniophora puteana and Rhodonia placenta in a stacked-sample decay test to produce samples in different stages of decay. Sorption isotherms were measured starting in desorption from the undried, decaying state to investigate their hygroscopic properties. Although there were substantial differences in degradative ability between the two fungi, the results revealed that decay by both species increased the hygroscopicity of wood in the decaying state, particularly at high relative humidity. The effect was stronger in the heat-treated samples, which showed a steep increase in moisture content at low decay mass losses. The reference samples showed decreased hygroscopicity in absorption from the dry state, while the heat-treated samples still showed an increase at low mass losses. Near infrared spectroscopy showed that the early stages of decay were characterised by the degradation of hemicellulose and chemical changes to cellulose and lignin, which may explain the increase in hygroscopicity. The results provide a new perspective on brown rot decay and offer insight into the degradation of heat-treated wood. • Heat-treated and reference samples were degraded by brown rot fungi. • Sorption isotherms were measured starting in desorption from the undried state. • Brown rot degradation increased moisture content in desorption in all samples. • Moisture content of heat-treated samples showed an increase also in absorption. • Near infrared spectroscopy indicated changes in hemicellulose, cellulose and lignin. [ABSTRACT FROM AUTHOR]

Archaeological shipwreck timber often contains elevated amounts of sulfur and iron rich compounds, accumulated during the long-term exposure in marine environments. This paper investigates if the accumulation of iron and sulfur is correlated and restricted to areas where microbial wood degradation takes place. Examination of microbial degradation in two pine and four oak samples from three historical shipwrecks situated in the Baltic Sea are carried out by light microscopy. Type, degree and amount of wood degradation by fungal and bacterial processes is compared to results on sulfur and iron accumulation studied by X-Ray Fluorescence (XRF) scanning. The highest accumulation of iron and sulfur is found in the surface layers (0–2 cm), where microbial degradation is also most intense. A novel finding is that both decay by erosion bacteria- and soft rot fungi promotes accumulation. Our results also imply that accumulation of inorganic sulfur and iron in archaeological wood involves several different processes which might include solely chemical as well as biogeochemical processes. The processes are different in pine compared to oak and the wood species of the shipwreck timber might therefore have a more important role than previously assumed. • Bacterial and fungal wood degradation stimulates accumulation of inorganic iron and sulfur. • Both biogeochemical and solely chemical processes might be involved. • Shipwreck timber of oak and pine accumulates iron and sulfur in different ways. • Interior parts of degraded pine show high concentrations of sulfur but not iron. • Interior parts of non-degraded oak show presence of both sulfur and iron. [ABSTRACT FROM AUTHOR]

Abstract The durability classes (DC) of heartwood from Sessile oak (Quercus petraea) and European larch (Larix decidua) were investigated by in-ground field tests according to EN 350 and EN 252. Tests were performed at five different European field sites. The performance of larch and oak was equal at all fields, resulting in the same average lifetime and DC values at each location. However, basidiomycete lab tests provided completely different durability values, for instance DC 1 for oak and DC 5 for larch. Additionally, the spectrum of fungi was analyzed at pine and beech stakes every half year, over a period of three years, using morphological methods and DNA analysis. The decay was mainly caused by white and soft rot fungi at all five test fields. The mycoflora was influenced by the wood species and the analyzed areas of the exposed specimens. The highest number of fungal species was found in the earth/air transition zone. A total of 98 fungi from 77 genera were detected, whereby not all of them were previously classified as wood degrading fungi. Highlights • Field test results for oak and larch durability fit to the current DC classification in EN 350:2016. • Lab and field test findings differ significantly with larch and oak. • Currently used lab test fungi are not representative of the practice. • Mycoflora is partially detectable by rDNA-ITS sequencing. • A more complete fungal community detection requires more comprehensive analysis methods such as NGS. [ABSTRACT FROM AUTHOR]

Abstract Decay patterns occurring in wood of hornbeam (Carpinus betulus) during natural decay in vivo were investigated and compared to decay in artificially inoculated wood in vitro. The fungal species causing decay was determined by morphological characterization and confirmed as Trametes versicolor using rDNA-ITS PCR and sequencing. T. versicolor caused degradation with properties of both simultaneous and selective white-rot. Chemical and FT-IR analyses suggested that T. versicolor caused severe reduction of lignin-carbohydrate complexes and guaiacyl lignin within the cell walls during natural decay. Under the light microscope, it was clear that decomposition of cell elements in the reaction zones of naturally decayed wood was greater than in inoculated wood. Histological analyses of inoculated wood blocks suggested that T. versicolor was able to switch from a typical simultaneous rot to selective delignification, with degradation of the middle lamella, and of lignin in cell corners. The results of our work demonstrated that test fungus able to attack the hornbeam tree by saprotrophic and parasitic life strategies. Highlight-IBB06 • Histological patterns of decayed hornbeam by T. versicolor indicated that cell decomposition in reaction zones was severe. • Chemical and FT-IR analyses showed that T. versicolor caused reduction of guaiacyl lignin in hornbeam in natural infection. • T. versicolor was able to switch from commonly rot to selective delignification by lignin degradation in ML and cell corner. [ABSTRACT FROM AUTHOR]

Fungi are the primary decomposers of wood across the globe. They redistribute the vast pool of wood carbon to other parts of the carbon cycle using mechanisms that also have intriguing potential in bioconversion and biotechnology applications. To make a living in the relatively sparse microenvironment of wood, these filamentous fungi must import many of their needs, including cations. Understanding the timing of cation import can help us validate the functions of cations in wood decay and create a clearer understanding of these complex wood degradation mechanisms. In this study, we resolved cation timing dynamics across space for two fungi (brown rot fungus Rhodonia placenta and white rot fungus Pleurotus ostreatus) using a wood wafer system. We found some expected patterns of the cation dynamics for both fungi, and a clear role for iron at the early stages of brown rot decay. On the other hand, the lack of an increase in manganese during initial white rot decay was surprising. Unexpectedly, we also saw a spike in copper during early brown rot decay that demands more investigation as a potential player in the brown rot mechanism. • Wood-degrading fungi overcome cation paucity in wood via active import. • Our wood wafer design enabled a high resolution map of cation import timing. • This timing supports the assumed functions for cations, such as iron in brown rot. • Copper is an apparent need in early brown rot, perhaps to assist in ROS production. [ABSTRACT FROM AUTHOR]

Western redcedar (WRC; Thuja plicata Donn) is widely used in outdoor building applications where the natural decay resistance of its heartwood is highly valued. However, as demonstrated in laboratory and field tests, the durability of WRC can be compromised under a variety of circumstances and conditions. The dynamics of the wood decay process are not well-understood. Several fungi, including more than 30 wood decay fungi, have been isolated from WRC wood products in service. However, little is known about the frequency with which these species occur, their succession patterns, the mechanisms involved, or their responses to fungicidal extractives. To ensure the accurate selection of WRC planting stock for heartwood resistance to fungal decay it is crucial that research be initiated to understand the relationship between WRC's natural durability and the suite of extractive-detoxifying and decay fungi that grow on WRC wood products. Moreover, improved knowledge of the fungi that biodegrade WRC wood products is essential for developing new approaches to improve the service life of this valuable species. [ABSTRACT FROM AUTHOR]

In the context of reduction of CO 2 emissions and costs in the construction industry, substitution of concrete by wood for foundation piles seems to be a promising alternative. To promote the use of local wood in pile foundation, diagnostic and prediction methodology of wood decay in soil need to be improved. Outdoor mesocosm decay experiments were performed to evaluate the potential use of beech wood as foundation piles. The stochastic occurrence of soil fungal inoculum in contact with mini-stakes and water gradient in wood explained the observed patchy wood decay pattern. Various patterns of wood rotting fungi were identified. The correlation between measured strength loss and mass loss was weak. Multivariate analyses using biochemical and physico-chemical data as inputs allowed section categorizations and prediction of wood strength. Accuracy of the prediction was validated by experimental measurement of the compression parallel to the grain (f c,o ). The categorization of unknown sections was computed by PLS-DA and provided clues inferring their service life. The described procedure has the potential to be transferred to on-site measurements to predict the f c,o of wood foundation pile or any potentially damaged timber structure. [ABSTRACT FROM AUTHOR]

The present work investigated the degradation of two Indian hardwoods ( Pithecellobium dulce and Tamarindus indica ) and the activities of lignocellulolytic enzymes by Pseudolagarobasidium acaciicola AGST3 and Tricholoma giganteum AGDR1. Laccase exhibited the highest ligninolytic activity, followed by manganese peroxidase and lignin peroxidase in both white rot fungi. Accessory enzymes such as aryl alcohol oxidase and cellobiose dehydrogenase showed higher activities till 21 days after incubation and then declined till 30 days. Xylanase and β-glucosidase were also found to be stable in both fungi during the degradation of hardwoods. The cultures, P. acaciicola AGST3 and T. giganteum AGDR1 accumulated high amounts of oxalic acid and produced weddellite (0.2–9 μm) and whewellite (5–21 μm) crystals, respectively. Comparative decay studies revealed that both the fungi were able to degrade lignin, cellulose and hemicelluloses of two hardwoods efficiently. During the pyrolysis reaction, decrease in onset temperature and activation energy was observed with the fungal treated wood as compared to the untreated wood. The basidiomycete cultures used in the study are efficient lignin degraders and can be applied as a pretreatment for second generation biofuels. [ABSTRACT FROM AUTHOR]

The biological resistance of different preservatives and mechanical properties of particleboard have a key role in panel performance. The attack ability of Microcerotermes diversus and Anacanthotermes vagans termites to particleboard evaluated and also, mechanical properties of particleboards measured. The alkaline copper quat (ACQ), boron-fluorine-chromium-arsenic (BFCA salts) and Chlorotalonil (CTL) were used to particleboard protection against termite. Degradation grading the termite attack was performed in accordance with the ASTM D 1758-06 specifications. This research was conducted in Sistan region for 18 months in field condition. Both weight loss and grading values indicated that the particleboard has the most degradation when exposed to Anacanthotermes vagans termite. The biological resistance of CTL-treated particleboard and control sample is the same. Treated specimens with BFCA and ACQ have a high biological resistance against the Microcerotermes diversus and Anacanthotermes vagans termites (5.5 and 13 percent weight losses, respectively). The weak mechanical strength such as internal bond is related to BFCA-treated particleboard (0.49 Mpa). ACQ-treated particleboard strength (0.74 Mpa) is similar to control sample (0.76 Mpa) and the highest strength value (1.25 Mpa) was obtained for particleboard made from CTL. In general, ACQ-treated particleboard indicated better performance than others particleboard. [ABSTRACT FROM AUTHOR]

We have developed a method based on isothermal calorimetry to monitor the colonization of wood materials by decay fungi. The heat produced is a direct and continuous measure of the activity (respiration) of the fungus. This pre-study shows that wood materials treated in different ways give results that reflect the known ranking of the materials regarding resistance to decay. In addition to this, the 40 days measurements show several phases and periods of oscillating respiration. As the calorimeter continuously monitors the colonization and degradation process, this method provides more information than classical/standardized decay tests in which typically only the final mass loss is determined. [ABSTRACT FROM AUTHOR]

Small wood specimens selected from six slash pine ( Pinus elliottii ) trees were inoculated with brown-rot and white-rot fungi and then evaluated for static modulus of elasticity (MOE) and dynamic MOE (MOE sw ). The experimental variables studied included a brown-rot fungus ( Gloeophyllum trabeum ) and a white-rot fungus ( Trametes versicolor ) for six exposure periods (2, 4, 6, 8, 10, and 12 weeks). The MOE sw was tested by a stress wave timer prior to static bending and the results were compared via regression analyses. Regression analyses indicated good correlations between static MOE and MOE sw . The R 2 ranged from 0.66 to 0.80 for non-decayed, brown-rot, white-rot, and all the specimens. [ABSTRACT FROM AUTHOR]

Copper based wood preservatives are among the most important wood preservatives for heavy-duty applications. Wood treated with copper-based preservatives performs excellently if applied according to preservative specifications. If used improperly, premature failures can appear. In order to elucidate the properties of copper treated wood in use, utility poles and posts treated with copper-based preservatives were investigated. Poles were cut into smaller specimens, and copper and chromium penetration, retention, mechanical properties, extractive content, short-term water uptake and fungicidal properties were then determined. The results clearly showed that wood retains its properties if treated with sufficient amounts of copper-based wood preservatives. Insufficient amounts of preservatives applied result in premature failures of wood commodities. Regardless of the type of wood preservative used, the central part of spruce wood poles and piles is the weakest point, where the majority of the failures occurs. [ABSTRACT FROM AUTHOR]

Conservation agents used to preserve heavily degraded wooden artefacts typically act as consolidants that restore the structural integrity of an object. However, treatments that can provide both dimensional stability and improved resistance to wood-decaying organisms are desirable because even degraded wood is still susceptible to further biodegradation. Some organosilicon compounds proved effective at stabilising waterlogged wood dimensions and could serve as potential multi-purpose conservation agents. To assess whether these chemicals can also impart decay and resistance to filamentous fungi, degraded model Scots pine wood was impregnated with three different organosilicon compounds: Methyltrimethoxysilane – MTMS, (3-Mercaptopropyl) trimethoxysilane – MPTMS, and Bis(diethylamino)-3-propoxypropanol)-1,1,3,3-tetramethyldisiloxane – DEAPTMDS), and moisture properties and durability of the treated wood were measured. All three organosilicons reduced treated pine hygroscopicity and provided various degrees of protection against brown-rot and white-rot fungi. However, only DEAPTMDS completely inhibited the growth of filamentous fungi after four weeks of incubation. The results show that tested organosilicons are suitable multi-purpose conservation agents for degraded wooden objects such as waterlogged archaeological wood because they can both consolidate and protect degraded wood from further biodeterioration. • All three organosilicon compounds tested can serve as multi-purpose agents to consolidate and preserve heavily degraded wood, like waterlogged archaeological wood. • All three organosilicon compounds tested lowered the treated wood hygroscopicity and improved its resistance to fungal decay caused by brown- and white-rot fungi. • Only the amino-siloxane inhibited the growth of filamentous fungi on the treated wood surface, while silanes were not as effective. [ABSTRACT FROM AUTHOR]

In 1995 remains of a 13th century shipwreck, "the Kronholmen cog ", was discovered in sandy soil at a golf green on the island of Gotland, Sweden. Prior to backfilling and in situ preservation, four sacrificial wood samples (SWS) of sound pine sapwood were installed for long-term monitoring of wood decaying processes. In year 2020, the site was re-opened to evaluate the protective nature of the site. All SWS and six archaeological samples were taken for a comparative analysis. Observations by light- and scanning electron microscopy showed severe microbial decomposition by fungi and bacteria. Based on occurrence of decay forms in the wood fibres, soft rot (SR) was identified as the main degrader of both SWS and in the first 2 cm of the heavily eroded archaeological material, accompanied by bacteria (type tunnelling bacteria (TB)). Moderate decay by bacteria (type erosion bacteria, EB) in archaeological samples indicated longer period during the last 700 years under waterlogged and anaerobic condition – e.g., protective. Only initial decay of erosion bacteria (EB) was observed in SWS, strongly indicating a non-protective environment during the last 25 years. Severe brown rot decay was established in SWS and archaeological wood located in the front of the wreck where burial conditions were most critical (0.5 m above groundwater level, and 0.4 below soil/air interface). Here, a total of 0.50 cm surface layer of SWS was lost, yielding an initial decay rate of 20% in 25 years. In general, surfaces were heavily attacked especially for archaeological samples, and plant roots penetrated the soft and degraded surface layer. We conclude that the site since backfilling in 1995 has been semi-oxygenated and has promoted more severe fungal decomposition of cultural heritage. Thus, the site is not able to protect and preserve the precious archaeological remains for future generations and actions must be taken. SWS are concluded to be an important technique for long term monitoring of archaeological sites preserved in situ. • Shipwreck timbers heavily degraded after 25 years of active in situ preservation. • Fungal wood decay takes place 1.5 m below ground. • In situ protection of cultural heritage failed at the terrestrial site Kronholmen. • SWS is a valuable tool for long- and short-term monitoring of wood degradation at archaeological terrestrial sites. [ABSTRACT FROM AUTHOR]

Wood properties and microbial community characteristics were compared between loblolly pine ( Pinus taeda L.) logs protected or unprotected from termites (Blattodea: Rhinotermitidae: Reticulitermes spp.) and other arthropods for two years in seasonally flooded and unflooded forests in the southeastern United States. Significant compositional differences were observed between treatments and between flood patterns for both bacterial and fungal communities. Bacteria were 8–9-fold more abundant in unprotected logs compared to protected logs in both flooded and unflooded forests, with the greatest abundance seen in unprotected and unflooded logs. Wood nitrogen and lignin contents were unaffected by treatment, flood pattern or levels of termite damage visible in unprotected logs. We conclude that termites alter the composition of both bacterial and fungal communities and thus have the potential to indirectly affect wood decomposition and related processes through interactions with the microbial community. [ABSTRACT FROM AUTHOR]

Wood protection against fungal decay is mainly based on chemical protection. Nontoxic protection methods have become more important in Europe due to environmental concerns. A method using electric fields to inhibit wood decay by fungi has been investigated in laboratory trials and wood mass loss and moisture content after exposure to fungal attack were determined. The results show significantly reduced mass loss for wood samples exposed to a low pulsed electric field (LPEF), while wood samples connected to alternating and direct current displayed higher mass loss compared to LPEF. Changing the electrode material reduced the mass increase due to metal ion transfer into the wood samples for LPEF-exposed samples. The use of conductive polymer instead of metal electrodes and carbon fibers was preferable as no ions were transferred and the integrity of the material persisted. Decay of pre-exposed wood samples to white rot could be stopped or slowed down by means of LPEF. [ABSTRACT FROM AUTHOR]

This paper examines how wood decay fungi affect the electrical resistance (resistivity) of wood to determine whether an electrical resistance probe could be deployed as a remote sensor in a wall to detect wood decay. Electrical resistance measurements were taken on wood blocks exposed to Gloeophyllum trabeum in a standard soil bottle tests (AWPA E10) as a function of time. To understand how and why resistance changed with time, results were compared against resistance measurements taken in sterilized, un-inoculated wood at high moisture contents; concentrations of certain mineral ions in the wood were also measured. Results indicate that most of the changes in electrical resistance in the soil bottle test could be described by changes in moisture content alone. When the moisture effects were removed, decay fungi decreased the resistance at small amounts of weight loss but increased the resistance at high weight loss. The results presented herein help to explain the mechanism by which empirical, electrical resistance nondestructive testing devices work and also the limitations on using resistance measurements to detect wood decay. [ABSTRACT FROM AUTHOR]

The extracellular lignocellulolytic enzymes secreted by Porodaedalea pini were investigated for their ability to degrade the wood of Picea jezoensis over various time periods. In addition, changes in wood chemical component contents were also investigated. Enzyme production and wood degradation by P. pini significantly increased starting at 60 days of incubation. The total lignin, holocellulose, and α-cellulose contents, as well as pH, decreased during the degradation process, while hot water, 1% NaOH, and ethanol-toluene extract contents significantly increased. These results indicate that P. pini simultaneously degraded the lignin and polysaccharides of P. jezoensis wood. Additionally, P. pini continuously produced xylanase, β-glucosidase, and endoglucanase with higher activities than those of exoglucanase and cellobiose dehydrogenase. Manganese(II)-dependent peroxidase showed the highest ligninolytic activity, followed by lignin peroxidase and laccase. These results indicate that P. pini produces a variety of lignocellulolytic enzymes, and that the produced enzymes contribute to the degradation of P. jezoensis wood components. [ABSTRACT FROM AUTHOR]

Natural extracts have become of high interest in the past ten years for their inhibiting the growth of molds over wood and wood products surfaces in service or during the storage of building materials. In the present study, the antifungal effects of three natural extracts applied to three woods against five common molds were assessed. The growth of fungal hyphae of Alternaria alternata , Fusarium subglutinans , Chaetomium globosum , Aspergillus niger , and Trichoderma viride on the surfaces of Pinus sylvestris , Pinus rigida and Fagus sylvatica woods treated with extracts of Pinus rigida (heartwood), Eucalyptus camaldulensis (leaves) and Costus speciosus (rhizomes) was visually estimated. GC/MS and FTIR analyses were used to identify the chemical constituents and the functional groups of extracts. α-terpineol (24.91%), borneol (10.95%), terpin hydrate (9.60%), D-fenchyl alcohol (5.99%), and limonene glycol (5.05%), which are the main constituents of P . rigida heartwood methanol extract. The main chemical compounds of methanol extract from Eucalyptus camaldulensis leaves were spathulenol (18.89%), cryptone (5.79%), 4,6,6-trimethyl-2-(3-methylbuta-1,3-dienyl)-3-oxatricyclo[5.1.0.0(2,4)]octane (5.79%), (3,3-dimethylcyclohexylidene)-(E)-acetaldehyde (5.57%), and ascaridole (4.32%). The main constituents identified in the distilled water extract from Costus speciosus rhizomes were meso -erythritol (12.21%), methyl-2-methyl-1,3-oxothiolan-2-yl-ketone (11.61%), (all-Z)-5,8,11,14,17-eicosapentaenoic acid-methyl ester (9.74%), diosgenin (5.07%), 2-ethyl-3-hydroxy-4H-pyran-4-one (4.43%), 3′,4′,7-trimethylquercetin (3.17%), and digitoxin (2.77%). Wood specimens treated at the level of 2% concentration of P . rigida heartwood extract observed good inhibition to the mold growth under laboratory conditions. These findings support the potential use of natural extracts for natural wood protection against mold infestation for surface treatment of wood. The results indicate that wood extracts may be useful for reducing the incidence of mold on wood products, but none of the materials evaluated completely inhibited the test fungi. These extracts may provide a useful value-added application for by-products of lumber production from these species. [ABSTRACT FROM AUTHOR]

Decayed wood samples were collected from naturally infected oak ( Quercus castaneifolia C.A.M.). Fruiting bodies of the basidiomycete white-rot fungus Pleurotus ostreatus were identified morphologically and confirmed with rDNA ITS sequencing. Cellulose and lignin compositions were determined and FT-IR spectroscopy was used to collect spectra from decayed and un-decayed wood samples. Histological aspects of decay were monitored by light microscopy. The results of the chemical analysis indicated that P . ostreatus decayed both cellulose and lignin in similar quantities. FT-IR analysis and microscopic images demonstrated that P . ostreatus exhibited simultaneous white-rot in naturally infected oak samples. [ABSTRACT FROM AUTHOR]

Synthetic polymers are widely used in the conservation of historical relics. These materials are attacked and deteriorated by microorganisms. The environmental factors also accelerate their deterioration. In this study, the antifungal properties of TiO 2 and ZnO nanoparticles in Polyvinyl butyral (PVB) were assessed. In three groups, samples were prepared from Poplar wood and they were treated with the nanocomposites under vacuum condition. Two groups were incubated separately in darkness and light conditions with rainbow fungus ( Trametes versicolor) for 7 weeks according to the Bravery method. The third group was studied after the accelerated aging due to temperature, humidity and UV light irradiation. Treated samples with 1% of nano-TiO 2 and nano-ZnO in 5% of PVB in darkness conditions, did not show antifungal properties. But 2% of these nanoparticles protected the wood against fungal in darkness conditions. There was an appropriate antifungal properties all treatments in light condition. The accelerated aging of the treated samples with the nanocomposite indicated the protective effect of this latter treatment against aging factors compared to the treated samples with the consolidant lacking nanoparticles. [ABSTRACT FROM AUTHOR]

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 IC 50 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. [ABSTRACT FROM AUTHOR]

In the past ten years natural extracts have been used as important potential applications to prevent mold growth on in-service wood. The growth of fungal hyphae of five common mold fungi ( Alternaria alternata , Fusarium subglutinans , Chaetomium globosum , Aspergillus niger , and Trichoderma viride ) on wood surface of Pinus sylvestris , Pinus rigida and Fagus sylvatica treated with the essential oil (EO) of P. rigida (wood) and Eucalyptus camaldulensis (leaves) was visually estimated. EOs were applied by vapor method and the mold growth inhibition was measured. The chemical constituents of the EOs was analyzed by GC/MS, which referred to the presence of α-terpineol (34.49%), borneol (17.57%), and fenchyl alcohol (14.20%) as the major components in P. rigida wood oil, and eucalyptol (60.32%), α-pinene (13.65%), and γ-terpinene (8.77%) in E. camaldulensis leaves. Complete inhibition against the growth of A. alternata , F. subglutinans , C. globosum , and A. niger except of T. viride by applying P. rigida wood EO at 5000 ppm and complete growth with all the studied fungi except of C. globosum at 156.25 ppm was found. Good inhibitions against C. globosum at 5000 ppm and 156.25 ppm and no inhibition against A. niger and T. viride and little inhibition against F. subglutinans at high concentration was found by the application of EO from E. camaldulensis leaves. These findings support the potential use of the EOs for wood protection against mold infestation for surface-treatment or fumigation of wood products. [ABSTRACT FROM AUTHOR]

Given the right climatic and environmental conditions, a range of microorganisms can deteriorate wood. Decay by basidiomycete fungi accounts for significant volumes of wood in service that need to be replaced. In this study, a short-wave infrared hyperspectral camera was used to explore the possibilities of using spectral imaging technology for the fast and non-destructive detection of fungal decay. The study encompassed different degradation stages of Scots pine sapwood (Pinus sylvestris L.) specimens inoculated with monocultures of either a brown rot fungus (Rhodonia placenta Fr.) or a white rot fungus (Trametes versicolor L.). The research questions were if the hyperspectral camera can profile fungal wood decay and whether it also can differentiate between decay mechanisms of brown rot and white rot decay. The data analysis employed Partial Least Squares (PLS) regression with the mass loss percentage as the response variable. For all models, the mass loss could be predicted from the wavelength range 1460–1600 nm, confirming the reduction in cellulose. A single PLS component could describe the mass loss to a high degree (90%). The distinction between decay by brown or white rot fungi was made based on spectral peaks around 1680 and 2240 nm, related to lignin. • A SWIR hyperspectral camera can be used to predict mass loss in Scots pine sapwood due to basidiomycete decay. • The main wavelength range of the prediction model is the spectral range 1460-1600 nm, related to cellulose. • The distinction between decay by brown or white rot fungi is mostly based on the lignin peaks around 1680 and 2240 nm. [ABSTRACT FROM AUTHOR]

Degradation of lignin and non-cellulosic polysaccharides (pectins and hemicelluloses) in Norway spruce wood (softwood) by the white rot fungus Pycnoporus sanguineus was investigated using transmission electron microscopy coupled with immunocytochemistry. P. sanguineus produced selective decay in xylem cells including tracheids, ray tracheids and ray parenchyma cells. Lignin was preferentially removed first from cell walls with hemicelluloses (xylan and mannan) and cellulose remaining. Lignin in compound middle lamella (CML) regions of tracheids was also preferentially degraded prior to degradation of xyloglucan (hemicellulose). This differs from the previous concept of wood decay by selective white rot fungi demonstrating concomitant degradation of lignin and hemicelluloses. In contrast, no clear preferential degradation of lignin prior to pectins and hemicelluloses was observed in middle lamella cell corner (MLcc) regions of tracheids which were the last regions to be attacked by the fungus. Micromorphologically, prominent cell separation between tracheids by delignification of CML regions before complete degradation of secondary cell walls was observed as evidence of selective decay. Variations in resistance to decay by the fungus depending on cell wall orientation (radial vs. tangential) of tracheids and between cell types were also observed. [ABSTRACT FROM AUTHOR]

Degradation of lignin and non-cellulosic polysaccharides (pectins and hemicelluloses) by the white rot fungus Pycnoporus sanguineus were investigated in European ash wood (hardwood) using transmission electron microscopy coupled with immunocytochemistry. Lignin was preferentially removed in secondary cell walls of ash xylem cells including fibers, vessel and (ray/axial) parenchyma cells prior to degradation of hemicelluloses (i.e. selective decay). Concomitantly, degradation of cell walls occurred by progressive thinning from the lumen surface outwards similar to simultaneous decay. Preferential degradation of middle lamellae before complete degradation of secondary cell walls (i.e. a typical feature of selective decay) was only observed in bi-/triseriate rays by initial attack from pit regions. Vessel and parenchyma cells showed greater resistance to decay than fibers with narrower decay zone produced. A comparison of decay between ash and spruce wood (Part I, softwood) demonstrated that P. sanguineus produces selective decay in both hard- and softwoods but more typical micromorphological features of selective decay are produced in spruce tracheids than ash fibers. This study highlights that degradation of lignin proceeds hemicelluloses in wood cell walls attacked by the selective white rot fungus P. sanguineus . [ABSTRACT FROM AUTHOR]

Two isolates of Chlorociboria aeruginascens (Nyl.) Kanouse incubated axenically on aspen wood blocks resulted in 18% and 32% mass loss after 134 wks (2 yrs 8 mo). Aspen wood decayed by C. aeruginascens contained cavities in the S2 layer of the secondary cell wall, similar to Type I soft rot attack, as well as erosion troughs and overall thinning and erosion of wood cell walls, resembling decay by Type II soft rot fungi. Using a selective medium, basidiomycete fungi were isolated from 9 of 17 samples of wood from a variety of tree species colonized and stained by Chlorociboria sp. (putatively C. aeruginascens ) in a mixed hardwood forest from northern North America. Basidiomycete fungi were identified by ITS sequencing and cultural tests and were shown to be predominantly species of common white rot fungi. In axenic decay tests with aspen blocks, basidiomycete isolates caused mass losses in the range of 10%–50% after 26 wks incubation. Decay tests in which a basidiomycete isolate was co-inoculated with an isolate of C. aeruginascens did not differ significantly (p < 0.05) in mass loss from those caused by the respective basidiomycete alone. Results suggest that decay of wood colonized by C. aeruginascens is principally caused by white rot fungi and is neither enhanced nor inhibited by the presence of C. aeruginascens. [ABSTRACT FROM AUTHOR]

The present study samples 19th century maps (belonging to India's Great Trigonometrical Survey) and daptars (official papers of Maratha history) to isolate the microflora and explore their interactions within that niche. Amongst the array of microbial isolates, the work successfully isolates a novel strain of Bacillus, producing a potent, low molecular weight, broad spectrum antagonistic protein fraction. The predominance of this species rendered the documents sampled resistant to biodeterioration in comparison to others. The antifungal activity of the isolate was attributed to a low molecular weight, heat, pH stable, extracellular protein fraction that was isolated with 30% and 60% ammonium sulfate precipitation. The activity of this fraction was established by bio-autography. Its stability upto 50 °C and resistance to proteolytic cleavage makes this protein fraction a novel broad spectrum potent antifungal candidate. [ABSTRACT FROM AUTHOR]

Ailanthus excelsa Roxb. requires less care than other species and thrives in arid and semi-arid regions. Therefore, it becomes an important choice for forestry programs. Young branches of these trees are frequently invaded by the fungus Bjerkandera adusta (Willd.) P. Karst. The main aims of this study were to characterize the wood decay pattern and evaluate the extent of damage caused by the fungus. Infected samples were studied using light microscopy, confocal laser scanning microscopy, transmission electron microscopy, and scanning electron microscopy. Wood of the dead branches became pale white and very soft. In vitro decayed wood showed extensive weight loss of wood blocks (68.6%) at the end of three months. In the xylem, fibres were the most severely affected cell types, whereas wall structure of the axial parenchyma remained virtually unaltered. Unlike axial parenchyma, walls of the ray cells formed several boreholes and finally collapsed in the advanced stage of decay. By contrast, the middle lamella of all the xylem elements remained intact even at the end of three months. In the early stages of infection, vessels appeared to be resistant to the fungal action but they also became eroded at the advanced stage. The degradation pattern showed anatomical characteristics of both the white-rot and soft-rot type of decay. Thinning of walls from the lumen side and appearance of U-notches resembles white-rot decay, while tunnels through the S 2 layer of the fibre wall added the characteristics of the soft-rot decay pattern. Extensive weight loss of wood blocks following infection suggests B. adusta is an aggressive wood-degrading fungus. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the resistance of black pine wood (Pinus nigra L.) vacuum-treated with zinc oxide, zinc borate and copper oxide nanoparticles against mold and decay fungi and the subterranean termites was evaluated. Some of the nanocompounds tested were forced with acrylic emulsions to avoid leaching. Results showed that mold fungi were slightly inhibited by nanozinc borate, while the other nanometal preparations did not inhibit mold fungi. Mass loss from fungal attack by Trametes versicolor was significantly inhibited by the zinc-based preparations, while the brown-rot fungus, Tyromyces palustris was not inhibited by the nanometal treatments. Notably, nanozinc borate plus acrylic emulsion imparted very high resistance in pine wood to the white-rot fungus, T. versicolor with a mass loss of 1.8%. Following leaching, all pine specimens treated with nanozinc borate, with or without acrylic emulsion, strongly inhibited termite feeding, i.e. mass losses varying at 5.2–5.4%. In contrast, the copper-based treatments were much less effective against the subterranean termites, Coptotermes formosanus. In general, nanozinc borate possessed favorable properties, that is, inhibition of termite feeding and decay by T. versicolor. [Copyright &y& Elsevier]

Abstract: Synthetic dyes are extensively used in a number of industries, such as textile dyeing. Due to their low biodegradability, they cause serious environmental pollution. Thus, in the present paper a partially-purified acid fungal laccase from the white-rot basidiomycete Coriolopsis gallica was entrapped into calcium alginate beads and applied to the decolorization of different synthetic dyes. Effects of immobilization conditions such as alginate concentration, CaCl2 concentration and the ratio enzyme/alginate (E/A) on the loading efficiency and immobilization yield were investigated. The optimal conditions for C. gallica laccase immobilization into Ca-alginate beads were 2% (w/v) sodium alginate, 2% (w/v) CaCl2, and 1:4 E/A (v/v). It was also found that laccase stability to pH and temperature increased after immobilization. Both the free and immobilized laccase alone showed a high efficiency to decolorize the anthraquinone dye Remazol Brilliant Blue R (RBBR) while a low decolorization yield was observed for the diazo dyes Reactive Black 5 (RB5) and Bismark Brown R (BBR) and the metal textile dye Lanaset Grey G (LG). The addition of the redox mediator 1-hydroxybenzotriazole (HBT) to the decolorization reaction increased significantly dye removal. The immobilized laccase retained 70% of its activity after four successive decolorization cycles except for BBR (51.2%). The results obtained showed that the immobilized laccase from C. gallica has potential for its application in dyestuff treatment. [Copyright &y& Elsevier]

Abstract: The durability of heartwood from European larch, Sessile oak and Scots pine was tested in laboratory against wood decay basidiomycetes and soft rot. The durability test was performed according to CEN/TS 15083-1:2005 with Coniophora puteana, Oligoporus (Poria) placenta and Trametes (Coriolus) versicolor. CEN/TS 15083-2:2005 was applied in order to test the timber with a bioactive soil substrate against soil rotting organisms. For Sessile oak, a very high durability against basidiomycetes (DC 1) was found in contrast to a low durability (DC 4) against soft rot fungi. Furthermore the results indicated that the durability of European larch and Scots pine is slightly deteriorated after leaching according to EN 84:1997. Beside this a minor influence of raw density on mass loss was detected for larch. [Copyright &y& Elsevier]

Abstract: This study evaluated the decay resistance of ash (Fraxinus excelsior L.), beech (Fagus sylvatica L.), and maple (Acer platanoides L.) wood impregnated by a full cell process with N-methylol melamine (NMM) and combined NMM-metal complex dye (NMM-BS) in aqueous solutions. Basidiomycete decay testing involved incubation with Coniophora puteana (brown rot) and Trametes versicolor (white rot) according to a modified EN 113 (1996) standard, while for the soft rot fungal resistance was evaluated following the standard ENv 807 (2001). NMM and NMM-BS modifications at a WPG range of 7–11% provided decay protection against brown rot resulting in a mass loss less than the required limit (3%). The NMM and NMM-BS modified wood showed increased resistance to white rot decay; however, a higher WPG is needed to prohibit attack from this hardwood specific fungus. The metal-complex dye alone revealed biocidal effects against basidiomycetes. An increased WPG in NMM or NMM-BS had a positive impact against soft rot decay and the lowest mass losses after 32 weeks of exposure were obtained with NMM modification at about 18–21% WPG. NMM modification at this WPG range, however, was not sufficient to protect the wood from soft rot decay. The wood of beech and maple showed slightly higher resistance to all decay types than ash, probably due to the poorer degree of modification of the latter. [Copyright &y& Elsevier]

Abstract: The resistance against white-rot fungus Trametes versicolor was studied for chemically modified samples of hardwood tropical species Teak (Tectona grandis) and Melina (Gmelina arborea), which were treated with acetic anhydride for three different reaction times. Acetylated samples with different weight percent gain (WPG) and untreated solid blocks were exposed to the fungus for ninety days. The weight percent loss (WPL) due to the fungal attack was determined for each treatment, for both treated and untreated samples. It was found that treated Teak samples have good protection against fungal attack, but WPG does not affect significantly this protection. For Melina it was found that at higher values of WPG, a higher protection is achieved. [Copyright &y& Elsevier]

Chitosan (C) is a natural antimicrobial compound that has been widely explored for wood protection, but its application is limited by its high leachability. Genipin is a biobased crosslinking agent that can crosslink with chitosan under mild conditions. This study aims at examining the decay resistance and leachability of genipin-crosslinked chitosan (GC) treated wood against common wood-decaying fungi. GC formation was confirmed using Fourier transform infrared spectroscopy and Thermogravimetric analysis. The antifungal efficacy of GC against two brown-rot fungi, Gloeophyllum trabeum (G.t.) and Rhodonia placenta (R.p.) and two white-rot fungi, Trametes versicolor (T.v.) and Irpex lacteus (I.l.) was first determined using malt-gar as substrate, which revealed that GC exhibited similar efficacy as C treatments in inhibiting the growth of all fungi studied. Micrographs of light and fluorescence microscopy showed changes in fungi morphology and nuclei deformation due to the effect of GC. GC-treated wood samples show an increased retention and mass gain as the function of treating concentrations, which were as high as 21 kg/m2 and 3.6%, respectively. However, upon leaching test, the mass gain of 3% GC treated softwood and hardwood was reduced to 1.6% and 0.9%, respectively, indicating cross-linking chitosan with genipin did not reduce the leaching rate of chitosan. In terms of durability testing, GC treated wood samples showed significantly lower mass loss ranging from 11 to 15% than those of the control groups of ≥30% regardless of the leaching test. • Chitosan can crosslink with genipin with improved thermal stability. • Genipin crosslinked chitosan has similar antifungal properties against common wood decaying fungi. • Genipin crosslinked chitosan treatment caused morphological changes and nuclei deformation of all the tested fungi. • Genipin crosslinked chitosan treated wood has limited improved leachability. [ABSTRACT FROM AUTHOR]

The spherical polyvinylpyrrolidone (PVP) stabilized red Se NPs (PVP–Se NPs) with a mean size of ∼45 nm were prepared via upgraded one-step wet chemical reduction by L-cysteine, which considerably shortened the synthesis procedure. Their morphological features were characterized by high-resolution scanning transmission electron microscopy, UV-VIS spectroscopy, and small-angle X-ray scattering method. The toxicological properties of PVP-Se NPs were analyzed by colorimetric cell viability assay based on the reduction of a yellow tetrazolium salt (XTT) in mitochondria, a further assay based on the measurement of lactate dehydrogenase (LDH) release from damaged cell membrane, and finally by cell proliferation assay. The antifungal effect of PVP-Se NPs alone, or in a mixture of commercial fungicide containing 2% of boric acid, 2% alkylbenzyldimethylammonium chloride, and ∼0.9% ethanolamine in distilled water was tested on the brown-rot fungus Serpula lacrymans The fungus belongs to important basidiomycetes causing economically significant decay of wood, mainly in houses and particularly cold soil cellars. The average mass loss tests performed on spruce wood blocks after four months of inoculation with S. lacrymans showed an enhanced antifungal effect of the mixture of PVP-Se NPs with a commercial fungicide than a PVP-Se NPs or commercial fungicide alone, which proved their synergistic effect on inhibiting fungi growth. Finally, scanning electron microscopy analysis of outer and inner parts of wood blocks treated with our novel mixture was performed. • The synthesis of PVP stabilized selenium nanoparticles is upgraded in one step. • Se NPs-BO mixture is 5 times more efficient than individual Se NPs or BO treatment. • Mass loss tests of wooden blocks prove the synergistic effect of our new mixture. [ABSTRACT FROM AUTHOR]

Abstract: The study investigated the termite resistance, physical and mechanical properties of particleboard made from waste tobacco (Nicotiana tabacum L.) stalk and Paraserianthes falcataria wood particles. Boards containing at least 25% tobacco stalk exhibited excellent termite resistance in laboratory no-choice feeding test against the Asian subterranean termite, Coptotermes gestroi Wasmann. Underground ground field exposure tests also showed that particleboard containing at least 50% tobacco stalk provided excellent protection against Philippine subterranean termites. Termite resistance of particleboard containing tobacco stalk is most likely due to the presence of residual nicotine in the samples. Addition of P. falcataria wood particles in all proportions used in this study resulted in boards with internal bond, stiffness and strength properties above the minimum set by the European standard EN 312-2 (1996) for general use particleboards. Boards containing 50–100% tobacco stalk showed high water absorption and thickness swelling after 24 h soaking in water. Results of the study showed that tobacco stalk can be used as an alternative material either alone or in combination with wood particles for the manufacture of particleboard with direct positive impact on disposal problem and efficient utilization of this waste biomass. [Copyright &y& Elsevier]

Abstract: Most European wood species do not have durable wood. In order to be used in outdoor conditions, non-durable material must be protected. Non-biocidal solutions for wood protection have been attracting a lot of attention, particularly in class 2 and 3 applications. One non-biocidal technique is treatment of wood with water repellents, such as wax emulsions and oils. Linseed oil and tung oil are frequently used water repellents. This research reports on the performance of linseed- and tung-oil-treated Norway spruce and beech wood against wood-decay fungi. Additionally, short-term hydrophobic properties were determined (with a tensiometer), as well as long-term hydrophobic properties (by soaking in water) in laboratory and outdoor conditions (electrical resistance measurements). Wood treated with tung oil and linseed oil is protected against brown- and white-rot fungi; however, tung oil was found more effective. Not only did the oils tested prove efficacious against wood-decay fungi, but also they worked against short-, medium-, and long-term water uptake as well. Oil treated wood takes up less water during laboratory tests, as well as during outdoor testing. [Copyright &y& Elsevier]

Abstract: Fungi play a considerable role in the deterioration of cultural heritage, as their contamination favours the decay of the materials used for historical art objects. Fungus prevention, the treatment of contaminated objects and their successive conservation are important items to restorers. Over the past decade, nanotechnology has been applied in several fields of cultural heritage conservation in order to prevent, for example, the chemical degradation of mural paintings and paper acidity. Nevertheless, nanomaterials have not been yet used as antifungal and biocidal agents for wood handworks. In this work we have treated eight different types of wood, some of which are commonly used in the field of cultural heritage, with a solution of titanium dioxide nanoparticles and placed them in contact with two species of fungi, Hypocrea lixii (white-rot) and Mucor circinelloides (brown-rot), which are known to be responsible for a fast decay of wood. Results show that the photo-catalytic activity of titanium dioxide nanoparticles prevents the fungal colonization of wood samples over long time when compared to untreated ones. [Copyright &y& Elsevier]

Abstract: Some imported timbers are well known for their durability and their reputation has carried them far from their original homes, although some have not maintained their reputation under different conditions or where new varieties of termites have appeared. It is necessary to know the behaviour of wood species under different environmental conditions and their durability class before the timber or timber product is put into use. The degree of wood deterioration is dependent on conditions such as soil, rainfall, altitude, temperature, and other environmental conditions under which the timber is put to use. Natural durability refers to the ability of wood species to resist attack by different agents, especially biological ones. This paper describes the natural resistance of important imported timber species of India against termites in different agro-eco zones. Field experiments were carried out at six locations falling under five Indian agro-eco zones with the aim of evaluating the natural resistance of 20 species of imported woods. Wood stakes measuring 30.5 × 3.8 × 3.8 cm as per IS:401-1982 standards were implanted in the soil and observed for a period of 4 yr, and visual damage assessment was done. The termites active in the test yard and on the test stakes were collected, preserved in 70% ethanol, and identified using taxonomic keys. Results revealed significant variation in rate of degradation of wood species with climatic zones producing significant variation as well. The tested timbers were categorized into three groups: susceptible, resistant, and moderately resistant. Termites collected belonged to nine species under four genera and the single family Termitidae. Odontotermes obesus was the dominant species in most of the locations. [Copyright &y& Elsevier]

Abstract: Fast-growing plant wood Populus ussuriensis Kom, and Micheliamacclurel wood were respectively modified by formation of wood-polymer composite to improve their decay resistance. Two functional monomers, glycidyl methacrylate and ethylene glycol dimethacrylate, added with a few Azo-bis-isobutryonitrile as initiator, and maleic anhydride as catalyst, were first impregnated into wood cell lumen under a vacuum-pressure condition, and then in-situ polymerized into copolymers through a catalyst-thermal treatment. The decay resistances of untreated wood and wood-polymer composites were assessed by weight loss and compared by SEM observations. SEM and FTIR analysis indicated that the in-situ polymerized copolymers fully filled up wood cell lumen and also grafted onto wood cell walls, resulting in the blockage of passages for microorganisms and moisture to wood cell walls. Thus, the decay resistance of poplar wood-polymer composite and Micheliamacclurel wood-polymer composite against brown rot fungus and white rot fungus in terms of weight loss achieved 3.43–3.92% and 1.04–1.33%, improved 95.06–95.18% and 95.10–95.35% than those of untreated poplar wood and Micheliamacclurel wood, respectively; and also respectively higher than that of boron-treated wood. The SEM observations for the decayed poplar wood, Micheliamacclurel wood and their corresponding treated wood also showed the remarkable improvement of decay resistance of wood after such treatment, which effectively protected wood from degradation by fungi. [Copyright &y& Elsevier]

Abstract: Decay resistance of pine sapwood treated with titanium alkoxide solutions was tested against the brown-rot fungi Coniophora puteana and Poria placenta for exposure times of 10 and 16 wk. In practice, wood-specimens were vacuum-impregnated by alcoholic solutions of titanium alkoxide with concentrations in the range of 5–16 mass % (solid content in solution) and subsequently cured under different humidity conditions. Results reveal that treated wood degraded up to 5% in comparison to untreated one that deteriorated 38% and 50%, respectively against both wood-decay fungi. Even full protection (mass loss below 3%) was achieved against brown rot with titanium alkoxide solution containing solid content of around 5 mass% with a weight percentage gain (WPG) of 9 mass%. With increased concentration, fungal resistance decreased slightly which was associated with more cracks and imperfections formed in the deposited layers of titanium dioxide in the adjacent wood matrix. Thermal analysis verified that a considerable amount of precursor remained in the wood structure as un-hydrolyzed organic residues. These organics, being bioactive, had the tendency to induce similar fungicidal effects as those of conventional fungicides. The amount of organic residues is correlated with the decay resistance of the tested samples. In a prolonged decay test, mass losses of 16-wk incubated samples do not show behavior different from that of the wood samples incubated for 10 wk. This result implies that the decay protection is permanent and confirms further the fungicidal activity of titanium-alkoxide-treated wood. [Copyright &y& Elsevier]

Abstract: Extracts of wound-associated beech wood (Fagus sylvatica L.) were spectrophotometrically analyzed and a paper disc screening test was applied to estimate their fungicidal potential against selected brown (Gloeophyllum trabeum) and white (Trametes versicolor) rot fungi. Colorimetric analysis revealed that higher amounts of total phenols, flavonoids and proanthocyanidins were characteristic of the reaction zone, and especially of wound-wood, while the lowest contents were measured in red heart samples. Estimation of the fungicidal properties of wound-associated wood extracts revealed that the evident inhibitory effect on wood decaying fungi can be ascribed to methanolic extracts of wound-wood, as well as to healthy sapwood. Extracts of reaction zones did not exhibit a corresponding inhibitory effect toward the chosen fungi. These results indicate a potential defensive function of wound-wood and sapwood in living trees, whereas already formed reaction zones behave as physical barriers rather than chemically inhibiting fungal growth. [Copyright &y& Elsevier]

Abstract: Field tests were used to evaluate the durability of fenceposts treated with 6.5 kg of chromated copper arsenate (CCA) per m3 of wood. Decay was assessed by qualitative visual analysis and by changes in the chemical structure of the wood. Leaching of CCA from treated fencepost was evaluated by atomic absorption spectroscopy. Moreover, extractives and the acid insoluble lignin were quantified. Treated wood was in perfect condition after 6 yr, in contrast to the untreated wood. Percentages of extractives and lignin increased in the untreated decayed wood. Cr and Cu both migrated from wood to soil, but the concentrations were below those allowed by local environmental law. [Copyright &y& Elsevier]

Abstract: In previous work, a ‘choice’ test was used to test wood durability in mixtures of wood types. Results demonstrated that a filamentous fungus (Gloeophyllum trabeum) made a ‘choice,’ degrading white pine significantly less when less-durable woods were readily available. For this experiment, we substituted white pine with copper-treated pine and used three fungi (G. trabeum, Serpula himantioides, and Wolfiporia cocos) representing a range of copper tolerances. Southern pine blocks treated commercially with micronized copper azole or treated in-house using copper ethanolamine were used as treated wood substrates. Trials were soil-block tests, using two-block combinations to include non-treated, non-durable pine or as single-block treatments. After 12 weeks of decay, copper tolerance by S. himantioides and W. cocos was evident while G. trabeum was not copper tolerant. Availability of non-durable pine blocks, however, had no effect on decay in copper-treated wood. This contrasts with our past results using white pine. The reason for the discrepancy may relate to fungal mechanisms of copper tolerance (e.g., constitutive oxalic acid secretion) which may differ from mechanisms to overcome extractives in white pine. More fungal research using choice trials to assess these ‘neighbor effects’ is logical, given increased use of mixed, composite, and hybrid materials. [Copyright &y& Elsevier]

Abstract: Unique historical shipwrecks in the Baltic Sea are exposed to continuous decay by specialised wood-degrading microorganisms. In this comprehensive literature study, current knowledge on microbial degradation in aquatic environments is synthesised and adapted to a cross-disciplinary context, to further understanding of the ongoing decay processes in shipwreck timbers today. Soft-rot fungi and erosion bacteria are the two most active groups of wood degraders. Their decomposition of the wood surface and interior are described, discussed, and finally compared with the available data from examined shipwrecks found in the Baltic Sea. The rate of decay depends on several parameters, such as wood species, environmental factors, duration of exposure (age of object), sediment protection, and physical damage. More consistent predictions on the longevity of wrecks are dependent on future research on the ecology of the microbes, combined with investigations of the historical wrecks themselves. This research is essential for successful in-situ protection and long-term preservation of significant historical shipwrecks. [Copyright &y& Elsevier]

Abstract: Essential oils and their derivatives might be one of the promising preserving agents to prevent fungal decay and termite/insect attack in wood since such compounds have a long history of safe usage as antimicrobial agents in various industries. Considerable research has focused on utilizing bioactive essential oils and wood extractives based on green technologies to develop environmentally friendly wood preservatives. This study evaluated biological activities of storax from Liquidambar orientalis tree, some storax constituents and commercial styrax against wood-decaying fungi, mold fungi, and termites in laboratory conditions. Scots pine sapwood specimens were treated with various concentrations of styrax, storax and storax constituents i.e. cinnamyl acetate, cinnamyl alcohol and ethyl cinnamate. Treated specimens were subjected to leaching followed by soil block decay tests using two brown rot and two white rot fungi. Specimens were also subjected to two different laboratory termite resistance tests based on the standards methods by the American Society for Testing and Materials (ASTM) and Japanese Industrial Standards (JIS). Inhibitory effects of the compounds were evaluated in vitro against Basidiomycetes, mold, and staining fungi. Treated wood specimens were also tested for mold growth. The storax constituents, storax and styrax did not inhibit fungal decay by the brown rot fungi. The constituents and storax-treated specimens resulted in mostly “moderate resistance” to fungal decay by the white rot fungi based on the ASTM D2017 classification. Styrax only was effective against the Basidiomycetes fungi in vitro tests; however, the mold and staining fungi tested were not completely inhibited. Natural storax at the concentration level of 0.5% inhibited all fungi except Trametes versicolor and Ceratocystis pilifera. Cinnamyl alcohol inhibited fungal growth with the exception of Aspergillus niger. In mold tests, complete inhibition was not observed for any of the test fungi; however, cinnamyl alcohol reduced mold growth considerably on treated wood specimens. Cinnamyl alcohol was also effective against termites in unleached specimens; however, styrax and natural storax at the concentration level of 10% reduced wood consumption in treated specimens. [Copyright &y& Elsevier]

Abstract: A lignocellulosic biomass treatment method utilizing wood rot fungi to improve cellulosic sugar solubilization for ethanol production was modified to provide larger samples for chemical analyses. Liriodendron tulipifera wood chips were treated in a novel application of aerobic polypropylene “spawn bags” as experimental bioreactors for biopulping. Treatments were inoculated with culture suspensions of white rot (Ceriporiopsis subvermispora) and brown rot (Postia placenta) fungi in 40 day incubations. Fungal growth occurred in all treatments, with extensive hyphal coverage of the biomass (ca. >80% of wood chip surfaces). After treatment, physical biodegradation, holocellulose, α-cellulose, and lignin contents of the fungal-biopulped wood chips were comparable to previous results. However, unlike in previous studies, the biopulped wood did not exhibit significant increases in soluble sugars after enzymatic hydrolysis. These results demonstrate that extensive fungal colonization of biomass is not necessarily sufficient for effective biopulping to increase production of free soluble sugars from wood. Environmental controls on hydrolytic activity by wood rot fungi are poorly known, but we hypothesize that treatment inoculation using nitrogen rich medium may have inhibited lignin-specific fungal hydrolysis of the wood. Future development of effective, standardized biopulping techniques for improving soluble sugar production from lignocellulosic biomass will require optimization of methods including characterization of inoculation nutrients and container effects on fungal metabolic activity. [Copyright &y& Elsevier]