• Journal of the Korea Furniture Society
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• v.25 no.3
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• pp.233-237
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• 2014

The eco-friendly preservatives such as ACQ or CUAZ have been used in landscape architectural facilities these days. In this study, the decay efficacies of ACQ treatments were evaluated according to domestic veneer species, concentration of ACQ, weathering test, adhesive type, and fungus type. In case of veneer species, hinoki cypress and yellow poplar showed the highest and lowest decay resistance, respectively. And the decay resistance appeared to be greater in plywoods bonded by resorcinol resin-bonded plywood and non-weathering treated plywood than polyurethane resin-bonded plywood and weathering treated plywood.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.716-725
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• 2016

In this study, MCQ (Micronized copper Quat) which was copper-based wood preservative, was investigated on decay properties by difference of the its infiltration volume. After pressure-treatment with different MCQ concentration, test specimens (Japanese Red Pine) were exposed by a brown-rot fungus (Fomitopsis palustris). At the end of the 12 weeks exposure to the fungus, untreated specimen was showed the mass loss of more than 35%, and the value of preservative effectiveness of MCQ by indoor decay was $3.99{\pm}0.42kg/m^3$. Therefore, MCQ should be pressure-injected at least $3.99kg/m^3$. The three dimensional of the specimens were observed by using the light microscope and scanning electron microscope, Untreated and treatment specimens with low concentration generally had underwent serious decays and had a lot of fungal hyphae. Howere, the formation of bore hole by hyphae were not observed. Mass loss and decay properties of specimens were affected by amount of MCQ injection. Therefore, it is necessary to the review of the adequacy of the MCQ injection amount in domestic environments.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.347-358
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• 2011

Fomitopsis palustris, a brown-rot basidiomycete, causes the most destructive type of decay in wooden structures. In spite of its great economic importance, very little information is available at the molecular level regarding its complex decay process. To address this, we generated over 3,000 expressed sequence tags (ESTs) from a cDNA library constructed from F. palustris. Clustering of 3,095 high-quality ESTs resulted in a set of 1,403 putative unigenes comprising 485 contigs and 918 singlets. Homology searches based on BlastX analysis revealed that 78% of the F. palustris unigenes had a significant match to proteins deposited in the nonredundant databases. A subset of F. palustris unigenes showed similarity to the carbohydrateactive enzymes (CAZymes), including a range of glycosyl hydrolase (GH) family proteins. Some of these CAZyme-encoded genes were previously undescribed for F. palustris but predicted to have potential roles in biodegradation of wood. Among them, we identified and characterized a gene (FpCel45A) encoding the GH family 45 endoglucanase. Moreover, we also provided functional classification of 473 (34%) of F. palustris unigenes using the Gene Ontology hierarchy. The annotated EST data sets and related analysis may be useful in providing an initial insight into the genetic background of F. palustris.

• 보존과학연구
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• s.33
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• pp.99-108
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• 2012

The white-rot fungus (Trametes versicolor) and brown-rot fungus (Tyromyces palustris), which cause damage to a variety of wooden cultural properties and buildings, such as drying of the wood tissue, decay and cracks, sponge, and discoloration, give rise to serious structural and aesthetic problems. Moreover, pest termites (Reticulitermes speratus kyushuensis Morimoto) can cause damages like hollowing the outdoor beams or pillars of wooden buildings and finally causing such buildings to collapse due to the termites' destruction of the inside of the beams or pillars, leaving only a thin layer on their surfaces. This study was conducted to determine the impact of the wood-decay fungus, a representative damage-causing microorganism, and of insects and termites on the termite ecology. The damage ratio was calculated as the weight of the timber, and the overall total mass was reduced from two kinds of rot fungi. The white-rot fungi reduced the total wood mass, but the brown-rot fungi were observed to have had an increasing tendency to do so. The wood mass was measured after drying to determine the destruction capacity of termites. As a result, the wood mass consumed by the brown-rot fungi was shown to be greater.

• Journal of the Korean Wood Science and Technology
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• v.21 no.1
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• pp.39-50
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• 1993

The purpose of this study was to describe the micromorphological changes in Korean red pine (Pinus densiflora S. et Z.) wood decayed by a major brown-rot fungus, Lentinus lepideus, using scanning electron microscope and transmission electron microscope. At the end of the 12-week exposure to the fungus in soil block procedure(ASTM 1971), test blocks sustained 5.02% weight loss. The formation of bore hole by hyphae and penetration of hyphae through bordered pit were not observed. Instead, fungal hyphae appeared to penetrate axially tracheid luminar from the the ray cells via cross field pits. Hyphae were mainly found in lignin rich cell corner regions of tracheids, and also extensive degradation of tracheid wall occurred in this region. Extensive degradation of $S_2$ layer occurred without noticeable alteration of the $S_3$ layer, but warty layer and compound middle lamella remained relatively intact. Localized erosion, the characteristic of white rot, was observed in some cell wall and wall components including lignin were found to be decomposed.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.112-121
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• 2015

In this study, Copper Azole (CuAz), a domestically available wood preservative for pressure treatment, was employed to perform an experimental research on its infiltration and decay properties in Japanese Red Pine. Test specimens were pressure-injected with CuAz-2 preservative to measure its preservative effectiveness, and then its impact on weight and mass losses. Furthermore, wood specimens were treated with CuAz-2 preservatives of various concentration levels before they were decayed with brown-rot-fungi in order to observe decay properties on light microscope (LM) and field emission scanning electron microscope (FE-SEM). As a result, untreated specimen by Fomitopsis palustris showed the mass loss of more than 40%, and the value of preservative effectiveness of CuAz-2 by indoor decay was $1,73-3.32kg/m^3$. The concentration levels of CuAz-2 preservative were shown to cause significant variations in terms of decay progresses in the cross section, radial section, and tangential section. By contrast, untreated specimens had underwent serious decays in early wood, late wood, longitudinal resin canals, and ray, which led to vertical destruction of wood texture. As for the radial section, ray tracheid, ray parenchyma cell, and window like pits were decayed and destroyed. In the case of tangential section, uniseriate rays and vertical resin canals were seriously decayed. In conclusion, this study indicates that the adequacy of the current CuAz injection amount should be reviewed in the domestic environment because there are significantly different decays at different decay conditions.

• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.48-53
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• 1996

Brown rot fungus, Tyromyces palustris, has been reported to cause the loss of strength accelerated by oxalate, a non-enzymatic low molecular weight acid, with minute weight loss of decaying wood in early stage. The production of oxalate in relation to wood decaying and the presence of oxaloacetase. an oxalate producing enzyme, were identified during the process. Tyromyces palustris produced the largest amount of oxalate among brown rot fungi. In order to find out the cleavage of pulp fiber, we submerged pulp fiber in oxalate solution and the results showed that the number of short pulp fiber was highly increased, compared with control solution. The pH of decaying wood was decreased to 1.77 which was close to that of saturated oxalate solution, pH 1.2, Thus, the oxalate was thought to be accumulated in the decaying wood, The oxaloacetase which accelerates production of oxalate was derived from fungus, and the production of oxalate by the enzyme was determined by using on UV/Vis spectrophotometer. Therefore, the oxalate was found to be produced by oxaloacetase during decay. The oxalate may cause the acid-hydrolysis of cellulose and hemicellulose. The oxalate was thought to reduce the degree of polymerization and increase the enzyme activity, which resulted in rapid loss of strength in early stage-an identical feature of brown rot fungus.

• Journal of Forest and Environmental Science
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• v.36 no.3
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• pp.225-232
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• 2020

Chemical modification of wood is an effective method to enhance the biological durability of wood with no toxic effect on the environment. In this study, wood of Triplochiton scleroxylon was modified using acetylation techniques. A total of one hundred wood blocks, (each 20×20×60 mm) obtained from a 22-year old T. scleroxylon tree were conditioned and acetylated at 120℃ in a bioreactor containing acetic anhydride for 60, 120, 180, 240 and 300 minutes. The percentage weight gain of acetylated wood was determined. The untreated (control) and treated blocks were exposed to Pleurotus ostreatus (white rot fungus) and Fibroporia vaillanti (brown rot fungus) after which moisture content (MC) and weight loss (WL) was monitored for 16 weeks. Data were analysed using descriptive and inferential statistics at p<0.05 level of significance. The percentage weight gain of acetylated wood samples increased with time from 10.4% (60 minutes) to 22.7% (300 minutes). MC of untreated blocks inoculated with Pleurotus ostreatus was significantly higher than those of Fibroporia vaillantii after 16 weeks exposure. There was no significant difference in the MC of the of the acetylated samples for the two fungi after 300 minutes reaction time. The WL of untreated blocks inoculated with Fibroporia vaillantii was higher than those of Pleurotus ostreatus, however, the two fungi showed no significant difference in the WL for the acetylated samples after 16 weeks exposure. Acetylation prevents moisture absorption and inhibition of fungi growth in acetylated wood compared to untreated wood, thereby enhancing the durability of Triplochiton scleroxylon.

• Mycobiology
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• v.42 no.2
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• pp.114-119
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• 2014

The wood decay fungi Antrodia P. Karst. play important ecological roles and have significant industrial and economic impacts as both wood degraders and sources of pharmaceutical and biotechnological products. Although each Antrodia species has distinct morphological characteristics, the misidentification rate is especially high due to their simple morphological characters. A combination of morphological and internal transcribed spacer region sequence analyses revealed that 27 of 89 specimens previously identified by morphology alone were correct, whereas 35 of these specimens were misidentified as other Antrodia species. We report here that seven Antrodia species exist in Korea (A. albida, A. heteromorpha, A. malicola, A. serialis, A. sinuosa, A. sitchensis, and A. xantha) and based on these specimens, we provide taxonomic descriptions of these species, except for A. serialis, which was only confirmed by isolate.

• Resources Recycling
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• v.18 no.5
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• pp.52-62
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• 2009

This research was carried out to formulate environmentally friendly wood preservatives with okara and to investigate the effects of the acid concentration used for the hydrolysis of okara and salt type on the decay resistance of the preservatives. Okara-based preservatives were formulated with okara hydrolyzates, which were prepared with 0, 1%, and 2% sulfuric acid at $25^{\circ}C$ for 1 hr, and salts such as copper chloride and/or sodium borate. The preservatives were treated into wood blocks by vacuum-pressure method, and then the treated wood blocks were leached in $70^{\circ}C$ hot water for 72 hrs. The fungal treatments of the leached wood blocks were conducted by brown-rot fungus, Tyromyces palustris, and white-rot fungus, Trametes versicolor, to examine the decay resistance of the preservatives. As the acid concentration used for hydrolysis of okara increased, the treat-ability and decay resistance of the preservatives were improved, which the leachability was decreased. Wood blocks treated with the okara/copper or okara/copper/borax, showed very good decay resistance against T. palustris and T. versicolor. However, wood blocks treated with the okara/borax and okara-free preservative solutions, were observed the fungal decay by T. palustris. The optimal conditions for the preparation of okara-based wood preservatives were formulated with okara hydrolyzed with 1% sulfuric acid, copper chloride and borax.