• The Plant Pathology Journal
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• v.35 no.6
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• pp.674-683
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• 2019

Some species of the Trichoderma genus are reported as the major problem in oak wood mushroom production in Korea. In spite of economic loss by the fungi, scientific information on airborne Trichoderma species is not much available. To generate information for disease management development we analyzed airborne Trichoderma. A total of 1,063 fungal isolates were purely obtained from indoor air sampling of cultivation houses used for oak wood mushroom using sawdust media. Among the obtained isolates, 248 isolates were identified as Trichoderma fungi including T. harzianum, T. atroviride, T. citrinoviride, and T. pseudokoningii, by morphological and molecular analysis. T. harzianum was dominant among the four identified species. All the four Trichoderma species grew fast on solid nutrient media tested (potato dextrose agar [PDA], malt extract agar [MEA], Czapek's Dox + yeast extract agar [CYA] and cornmeal dextrose agar). Compact mycelia growth and mass spore production were better on PDA and CYA. In addition, T. harzianum and T. citrinoviride formed greenish and yellowish mycelium and spores on PDA and CYA. Greenish and yellowish pigment was saturated into PDA only by T. pseudokoningii. These four Trichoderma species could produce extracellular enzymes of sawdust substrate degradation such as β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease. Their mycelia inhibited the growth of oak wood mushroom mycelia of two tested cultivars on dual culture assay. Among of eleven antifungal agents tested, benomyl was the best to inhibit the growth of the four Trichoderma species. Our results demonstrate that the airborne Trichoderma fungi need to be properly managed in the cultivation houses for safe mushroom production.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.1-7
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• 1995

The crystal transformation from cellulose I to cellulose II during alkaline swelling of waste wood, which has been used for cultivating oak mushroom(Cortinellus edodes (Berk.) Ito et Imai), was investigated and compared to that of normal wood by a series of X-ray diffraction analysis. When the sapwood of cultivated wood was treated with 20% NaOH solution for 2 hours, the cellulose I can be easily transformed into Na-cellulose I than normal wood or heartwood of cultivated wood. Certainly the formation of Na-cellulose in wood is proportional to alkali swelling duration, and the formation of cultivated sapwood was faster than that of the other woods. Cellulose I in the sapwood of cultivated wood was easily transformed into cellulose II during mercerization, but the sapwood of normal wood and the heartwood of cultivated wood hardly converted to cellulose II. Namely, most of Na-cellulose I in normal wood can be reconverted to cellulose I in the process of washing and drying. Therefore, it can be concluded from this study that in cell wall lignin and hemicellulose can prevent the alkaline swelling of cellulose in wood and the transformation from cellulose I to cellulose II as well.

• Journal of the Korean Wood Science and Technology
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• v.16 no.2
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• pp.90-97
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• 1988

The rate of utilization of the oak cork (bark of Quercus variabilis Blume) ranges only 40-50%. Therefore, this study was carried out to investigate the chemical properties of the oak cork for increasing the utility. 1) The contents of alkali extractives, organic solvent extractives and ash in the oak cork are similar to those of other barks, but hot and cold water extractives and lignin contents are lower than those of the wood. The carbohydrate (cellulose and hemicellulose) content of the oak cork is similar to that of other barks. The suberin contents in the first and the second bark of the oak cork are 34.8 and 32.2% respectively, in the dry weight. 2) Inorganic component contents of the first bark are similar to those of the second. The pH of the first and the second bark are 3.9 and 4.2%. The caloric values of the first and second bark are 6,263 Kcal/kg, and 5,828 Kcal/kg, respectively, and these caloric values are higher than those of other barks. The sclerencymatous cell content of the first bark which is related to the quality of the oak cork is lower than that of second bark, the contents of the sclerenchymatous cell and lignin show the positive correlation. 3) In the dimension of the cross sectioned cork cell, the first bark is bigger than that of the second. The shape of the cork cell is globular shape in the early bark and discoid shape in the late bark. The cross and the radial section are the same shape, but the tangential section shows difference from the other section.

• Journal of Climate Change Research
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• v.4 no.1
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• pp.41-49
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• 2013

Recent findings have revealed that black carbon is one of the substantial materials affecting climate change along with greenhouse gases. Usually, black carbon is generated by incomplete combustion of biomass and deposited on snow and ice surface, resulting in increasing adsorption of radiant energy and accelerating ice melting. However, it is still questionable what the emission characteristics of black carbons from biomass combustion is. We investigated the emission characteristics of black carbon generated from a wood stove in this study. We found that the emission of black carbon was highly dependent upon combustion temperature and the amount of combustion air supplied. The emission factors were 1.01 g-BC/kg-Oak for fireplace wood burning under incomplete combustion, 0.37 g-BC/kg-Oak for fireplace wood burning under complete combustion and 0.29 g-BC/kg-Oak for small wood-stove burning.

• Journal of the Korean Wood Science and Technology
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• v.9 no.3
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• pp.24-30
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• 1981

This experiment was carried out to determine the drying time from green to oven dry and estimate the moisture content of wood, such as red lauan (Shorea Spp.), Douglas fir (Pseudotsuga menziesii), Birch (Betula platyphylla), and oak (Quercus aliena), at various thickness, paralleled to fiber, of specimen for M.C. by oven dry method (100-105$^{\circ}C$). The results obtained are summarized as follows: 1. The drying time from green to oven dry decreases as the thickness of specimen for M.C. becomes to be thined, and that time at 10mm thickness are 14 hrs, for birch wood and 24 hrs, for oak wood. 2. The relative formulae between thickness (X) of specimen for M.C. and drying lime (Y) from 12% to oven dry are showed in Fig. 3. 3. The M.C. based on the weight of specimen for M.C. at t% can be obtained from the formula (2), and the drying time to 1% are shorter than that time to oven dry by approximately three times.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.15-21
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• 2006

The objective of this research is to develop the technique for carbonization of wood pellet and analyze a possibility for the utilization of carbonized wood pellet. The properties of wood pellet charcoals, such as density, yield, elemental composition, higher heating value, and methyleneblue adsorption, were analyzed. Wood pellet was made of sawdust of Hyunsasi-poplar, Japanese larch, Korean pine, Korean red pine, and Jolcharn-oak (serrate oak), respectively. The high density charcoal ($0.5{\sim}0.7g/cm^3$) was yielded from densified wood pellet. The carbon contents and calorific values of wood pellet charcoals were increased with the increase of carbonization temperature. The methyleneblue adsorptivity of wood pellet charcoal was similar to that of wood charcoal.

• Biomolecules & Therapeutics
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• v.13 no.1
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• pp.41-47
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• 2005

The study was conducted to determine whether oak wood vinegar extract influences blood alcohol concentration and hangover syndrome in healthy volunteers. 2% wood vinegar extract was effective to inhibit increase of blood alcohol concentration after alcohol intake and showed significantly different (P<0.1) compared to placebo. By result of questionnaire of volunteers, wood vinegar extract showed effects improving hangover syndrome. In comparative study about blood alcohol concentration and hangover syndrome of wood vinegar extract and other extract that hangover improvement effect was reported, average maximum blood alcohol concentration was lowered in those taking wood vinegar extract than those taking other extract. At drinking completion 210minutes (T210), blood alcohol concentration of those taking wood vinegar extract was the lowest by 0.063% compared with other extract but was not significantly different between in those taking wood vinegar extract and in those taking other extract. However, wood vinegar extract's experimental group was the highest by 0.462 in decrement rate of blood alcohol concentration and, when did P<0.1 by significance level, indicated difference that mean statistically compared to placebo group uniquely. At those taking wood vinegar extract, the improvement rate and the aggravation rate of hangover syndrome was each 87%, 2%. Thus it was concluded that wood vinegar extract showed excellent alcohol oxidation and was effective in hangover improvement.

• Journal of the Korea Furniture Society
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• v.19 no.4
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• pp.294-299
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• 2008

Collapse is an abnormal shrinkage resulting in uneven, rough surfaces and/or warping of sawn timber. The maximum abnormal shrinkages of the oak and persimmon specimens were obtained by the quasi-equilibrium drying and were compared with the other drying methods. The effect of steaming and freezing treatments on the shrinkage of wood was also investigated. The Quasi-equilibrium drying used in this study was proved as a good tool to make the maximum abnormal shrinkage of wood. The maximum abnormal volumetric shrinkage possibly caused by collapse could be 16.3% and 14.3% for the oak and persimmon specimens, respectively. In general the steaming-treated specimens shrank less than the controls for the oak specimens, but did more for the persimmon specimens. The volumetric shrinkages of the freezing-treated specimens were more various between the drying methods than those of the control and steaming-treated specimens.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.8-16
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• 2002

This study was performed to produce the high reactive lignin zero substrates from autohydrolyzed wood resources. In chemical compositions of used raw-materials, there were significant differences between two species, Japanese larch (Larix leptolepis) and oak (Quercus mongolica) woods. Japanese larch contained 25 to 3.5 times higher amounts of extractives than oak wood, which is mainly derived from high content of arabinogalactan in Japanese larch wood. Oak wood has 5% lower lignin content and 3% higher holocellulose and pentosans than larch wood. Concerned to changes in wood components during autohydrolysis pretreatment at 22 kg/cm² steaming pressure for 5~60 min, glucose content was constant during pretreatment, while hemicellulose and lignin were abruptly changed. Hemicellulose fraction was decreased significantly and lignin contents increased because of its condensation reaction with hemicellulose degradation products. The pH of hydrolyzates during pretreatment was decreased, reached upto pH 3 and since then leveled off. In the case of oak wood, same tendency was observed as in Japanese larch. Autohydrolysis followed by sodium chlorite and sulfite or bisulfite pretreatment was very effective in delignification of the substrates. In particular, two-stage delignification of autohydrolyzed woods with alkali and O₂-alkali resulted in very low lignin content substrates, such as 0~0.2% lignin substrate.

• Journal of the Korean Wood Science and Technology
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• v.17 no.2
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• pp.65-73
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• 1989

Steam explosion process is an efficient pretreatment method for sparating and utilizing wood main components has attracted attention in utilization of ligno-cellulosic biomass. In order to obtain the effective pretreatment condition. this study was made explosion apparatus. examined the composition. extraction of exploded wood. Wood chips of pine(Pinus densiflora oak (Quercus serrata) and birch wood (Belula platyphylla var. japonica) were treated with a high pressure steam(20-30 kg/$cm^2$, 2-6 minutes). The results can be summarized as follow; In analysis of exploded wood(EXW). It was found arabinose residues rapidly decreased with increasing of steaming time and pressure. Extractives of EXW with sodium hydroxide increased with increasing of steaming-time and- pressure especially extractives 1% sodium hydroxide has higher than other extracted method extractives of hard wood(oak, birch) has higher than pine wood. In EXW extracted with sodium hydroxide and methanol lignin was partially delignified alkali extraction was more delignified than methanol extraction hardwood than pine wood.