• 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.

• Mycobiology
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• v.42 no.2
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• pp.140-146
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• 2014

In Seoul, a majority of plant communities have undergone significant changes over the last few decades; however, how wood decay fungi have responded and adapted to the changes in vegetation remains unknown. Through an ongoing investigation of Korean indigenous fungi, ca. 300 specimens with poroid basidiocarp were collected in Seoul during 2008~2012. Morphological examination and molecular analysis using the internal transcribed spacer and nuclear large subunit ribosomal DNA region sequences helped identify 38 species belonging to 28 genera, 10 families, and 5 orders in this area. Among them, three polypores, Abundisporus pubertatis, Coriolopsis strumosa, and Perenniporia maackiae were found to be new to South Korea.

• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.21-32
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• 2019

In order to investigate the decay process of wood treated with preservative, waterproofing agent and their compound systems, a full-cell process was applied to impregnate the sapwood of poplar (Populus cathay) at paraffin wax emulsion concentrations of 0.5% and 2.0%, Copper Azole (CA) concentrations of 0.3% and 0.5%, and their four compound systems, respectively. Leaching tests and laboratory decay resistance against the white-rot fungus Corious versicolor (L.) Murrill for treated wood were carried out according to the America Standard E11-06 and China Standard GB/T 13942.1-2009. At certain time intervals during the decay test, samples were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction technique (XRD) to investigate the time-dependent changes of chemical components and crystalline structure, thus clarifying the decay mechanisms. The results suggested that white-rot fungi degrade hemicellulose and lignin in the wood cell wall first, followed by a simultaneous degradation of polysaccharides and lignin. Besides, CA could not only slower the decomposition of both hemicellulose and lignin, but also reduce the degradation amount of hemicellulose. However, paraffin wax emulsion at high concentration had a negative effect on the impregnation of CA for the compound system treated wood.

• Journal of the Korean Wood Science and Technology
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• v.20 no.4
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• pp.49-56
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• 1992

Seven white rot fungi (Irpex lactenis, Coriolus hirsutus, Lopharia mirabilis, Schizopora paradoxa, Ganoderma lucidum, Pleurotus ostreatus and Pycnoporus coccineus) native to Korea and two famous exotic lignin degradable white rot fungi (Coriolus versicolor and Phanerochaete chrysosporium) were investigated to clarify their physiological and physicochemical characteristics on white-rotted wood blocks. G. lucidum degraded wood blocks more seriously than those by exotic lignin-degrading fungi, C. versicolor and P. chrysosporium, but only slightly decreasecl the strength of wood which was compared to the weight loss, persumably on the account of its small use of cellulose when attacking wood. It is quite interesting to note that the holocellulose degradation rate of G. lucidum was also higher than any of the other tested fungi. The order of fungi, according to the lignin-decomposing rates, was G. lucidum>P. coccineus>C. versicolor>S. paradoxa>P. chrysosporium>L. mirabilis>P. ostreatus>C. hirsutus>I. lactenis. The lignin degradation of G. lucidum and P. coccineus which were collected in Korea was greater than that of C. versicolor and P. chrysosporium. If holocellulose degradation is not considered. G. lcidum has the merit of actual application in biomass conversion due to linin removal.

• Mycobiology
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• v.44 no.4
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• pp.217-236
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• 2016

Polyporoid and corticioid fungi are among the most important wood-decay fungi. Not only do they contribute to nutrient cycling by decomposing wood debris, but they are also valuable sources for natural products. Polyporoid and corticioid wood-inhabiting fungi were investigated in Odaesan National Park. Fruit bodies were collected and identified based on morphological and molecular analyses using 28S and internal transcribed spacer regions of DNA sequences. As a result, a total of 149 species, 69 genera, 22 families, and 11 orders were recognized. Half (74 species) of the species were polypores, and the other half (75 species) were corticioid fungi. Most of the species belonged to Polyporales (92 species) followed by Hymenochaetales (33 species) and Russulales (11 species). At the genus level, a high number of species was observed from Steccherinum, Hyphodontia, Phanerochaete, Postia, and Trametes. Concerning distribution, almost all the species could be found below 1,000 m, and only 20% of the species were observed from above 1,000 m. Stereum subtomentosum, Trametes versicolor, T. hirsuta, T. pubescens, Bjerkandera adusta, and Ganoderma applanatum had wide distribution areas. Deciduous wood was the preferred substrate for the collected species. Sixty-three species were new to this region, and 21 species were new to Korea, of which 17 species were described and illustrated.

• Journal of the Korea Furniture Society
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• v.19 no.1
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• pp.83-90
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• 2008

Gypsum-wood composites were made by introducing inorganic substances into wood using calcium chloride, first treating solution, and sodium sulfate, secondary treating solution, by double diffusion process under atmospheric pressure at room temperature. The process conducted as follows: water saturated specimens were soaked in calcium chloride solutions at several concentration. Then the specimens were soaked further in saturated sodium sulfate solution, and they were leached in flowing tap water for 24h. To attain sufficient weight percent gain (WPG) values, the suitable concentration of calcium chloride and soaking time in saturated sodium sulfate solution were 20% and 48h, respectively. Inorganic substances were produced mainly in the lumina of tracheides. It was made sure that these substances were dihydrate gypsum($CaSO_4$ $2H_2O$) by X -ray microanalysis (SEM-EDX). The composites had good fire resistance due to low heat transfer rate of gypsum formed in wood. However, the composites had little decay resistances, because they showed high weight losses by test fungi attacks.

• Korean Journal of Microbiology
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• v.18 no.1
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• pp.1-6
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• 1980

Five species of food decay fungl, Aspergillus flavus, Asp. uiger, Penicillum sp., Botrytis cinerea, and Rhizopus stolonifer, were examined for their radio sensitivity in several suspension media. Asp. flavus, Asp. niger and Penicillum sp. have almost the same sensitivity toward gamma rays. with D value in the range of 30 to 35 K rad, whereas Botrytis cinerea has a D value of approximately 55K rad and Rhizopus stolonifer, the most re4sistant fungus studied, has a crease in their radioresistnace when compared with spores irradiated in water. Asp. flavus and penicillium sp. spores irradiated in citrate buffer at pH3-7 showed almost no change in their radisensitiity with pH, but Botryis cinerea spores showed a distinct decrease in their radioresistnace at pH 6 and 7. Penicillum sp. spores irradiated in sucrose solutions showed no sinificant change in their radioresistance. Botrytis cinerea spores displayed a higher radioresistance when they were irradiated in sucrose solution than in water.

• Journal of the Korean Wood Science and Technology
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• v.36 no.2
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• pp.73-78
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• 2008

Inorganic chemical treated wood was prepared by impregnation of calcium or magnesium chloride ($CaCl_2$ or $MgCl_2$) solution and immersion in saturated solution of ammonium fluoride ($NH_4F$) as a reactant in order to make an introduction of a refractory fluorides with fungicidal and insecticidal effects in wood. The weight percent gains (WPGs) were increased with increase in concentration of calcium chloride or magnesium chloride solution, and were higher in treatment with calcium chloride than with magnesium chloride. Inorganic substances were produced mainly in the lumina of tracheides. These substances were proved to be the calcium fluoride or magnesium fluoride by the energy dispersive X-ray analyzer in conjunction with a scanning electron microscope (SEM-EDX). The treated wood showed good decay resistance because the weight losses were hardly occurred by the test fungi such as Tyromyces palustris and Trametes versicolor. The fire resistance effect was superior to the treated wood compared with that of the untreated wood.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.315-321
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• 1994

In order to prevent the postharvest decay and to promote the freshness retention of fruits and vegetables grapefruit seed extract(GFSE), natural microorganism control agent, was applied to the preservation of fresh fruits and vegetables. Freshfruits and vegetables treated with GFSE and stored in polyethylene film (0.1mm) at 1$0^{\circ}C$-15$^{\circ}C$ of natural low temperature low kept better qualities in color and texture than the GFSE -not- treated control. The treatment using GFSE ina 250ppm to 500ppm concentration seemed to be an effective one for the control of Botrytis cinerea isolated in red wine grapes. After 4 weeks of storage the firmness rate of cucumbers treated with the dilute GFSE was four times higher than that of non-treated ones. GFSE showed effective inhibitory action towards plant pathological bacteria and fungi which were involved in the decay of fruits and vegetables. Minimum inhibitory concentrations of GFSE towards them were in the range of 250ppm to 500ppm .Direct visualization of microbial cells and spores using electron microscopy showed microbial cells and fungal spores the function of which was destroyed by treating with the dilute solutions of GFSE. It was observed that GFSE would reduced disease damages and have bactericide & fungicide properties during the storage of such fruits and vegetables as egg plant, wild edible greens , kumquat, and kiwi fruit.

• The Korean Journal of Ecology
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• v.9 no.1
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• pp.9-18
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• 1986

The decomposition of litters of Pinus densiflora and the growth of microbial populations in a calcareous region, Youngwal were compared with those in a noncalcareous region, Sinlim. The decay rate of litter in Pinus densiflora in Youngwal was 0.128 and that in Sinlim was 0.096. The differences in the populations of soil bacteria and total microorganisms between the two regions were signficant at the 5% level, but that of fungi and actinomycetes was not at that level. The differences in the content of calcium and pH value of soil between the two regions were significant at the 1% level. The excessive content of calcium became to increase pH value, in turn the high pH decreased the content of available phosphorus in soil. The vertical distribution of the content of available phsophorus was consistent with that of the populations of fungi and actinomycetes in Youngwal.