• Journal of the Korean Wood Science and Technology
• /
• v.31 no.4
• /
• pp.71-80
• /
• 2003

The lignin degrading fungi were isolated from decayed woods and fruiting bodies gathered in forest area. Lignin degradation ability was investigated by Klason lignin of microbial treated pine wood. Among selected fungi, CJ-6 had 49.48% Klason lignin loss which was greater than 40.58% shown by Trametes versicolor that it is known as a typical lignin degrading fungus. Also, the biodegradation process and morphological features of degraded pine wood by selected fungi were observed with the scanning electron microscope. At the stage of 20 days incubation, mycelia invasion was observed without any failure of wood structure. At 60 days, wood decay was gone in some degree and one part of tracheid and ray wall was destroyed. At 100 days, tracheid wall was severely destroyed, and distinction between ray cell was difficult as cell wall was decayed much.

• 한국문화재보존과학회:학술대회논문집
• /
• 2001.11a
• /
• pp.27-34
• /
• 2001

Following the recommendations made by the cultural authorities the wooden cultural properties (WCP) had been treated with fire-retardants for fire protection. However, visual inspections of some of the WCPs treated with fire-retardants showed microbial decay. The work was extended to examine the micromorphological characteristics of the WCPs in a Buddhist temple which had been treated with fire-retardant. Microscopic examination showed the presence of typical soft rot cavities along the length of microfibrils in the secondary wall. Bacterial attack was also observed by scanning and transmission electron microscopy. It is interesting that the decay patterns observed in the Buddhist temple were very similar to those observed in the waterlogged woods. Presumably chemicals in the fire-retardants used rendered the wood susceptible to attack by soft-rot and bacterial decay by causing an increase in the moisture content of wood. Further studies are needed to investigate the effect of fire-retardants used currently on the hygroscopicity and the strength of wood materials in the WCPs. Microbial attacks caused degradation of the secondary cell walls and in some cases also of the middle lamella. In addition, the cell walls in the outer parts of wood were also degraded due to weathering, and cell separation occurred from total disintegration of the middle lamella.

• Journal of the Korean Wood Science and Technology
• /
• v.35 no.1
• /
• pp.64-72
• /
• 2007

The biodeterioration behaviors of square post to support the wooden printing blocks Shelves in the Janggeongpanjeon were investigated according to the positions and parts of square post, and environmental conditions. It was found that a high differences of deterioration in the progressing levels of wood decay, according to the positions and parts of square post, and environmental conditions. The decay levels were very high and still progressing in the contacted areas with stone foundation which are about up to 50 cm above it. In the decay type, white rot fungi was mainly affected in the inside of building which mainly made of softwood. The decay in the square posts to support the wooden printing block shelves inside of building was worse in the rear side, compared to front side. The insects was not found in most of square posts excluding the post which was neighboring at the infected round column by insect.

• The Microorganisms and Industry
• /
• v.15 no.2
• /
• pp.20-23
• /
• 1989

목재부후 민주름버섯류의 분류는 아직도 해결해야 할 문제점들이 많이 남아 있다. 그 이유는 민주름버섯류가 그만큼 특징들이 다양하고 형태는 유사하나 기원이 다른 이질적인 종류들로 구성되어 있기 때문이다. 민주름버섯류의 분류 대가인 Donk도 자신이 추구한 분류체계에 스스로 만족하지 못하고 후대의 학자들이 도전해야 할 문제점들을 자주 제시한 적이 있다. 이와 같은 현상은 민주름버섯류의 분류가 자연분류와 계통분류를 지향하여 보다 종합적인 방법으로 종의 개념에 접근할 필요가 있음을 시사한다. 이제 위에 언급한 영양생활, 형태, 배양, 또는 유전적인 특징외에 진화와 계통, 환경과 생태, 지리적 분포와 식생, 핵산구조와 분자계통분류 등과 같은 과제들을 아울러 다룰 수 있는 포괄적인 분류체제의 대두가 요청되고 있다.

• Korean Journal of Microbiology
• /
• v.36 no.3
• /
• pp.192-195
• /
• 2000

Degenerate primevs corresponding to the consensus sequences of the copper-binding regions in the N- and Cterminal domains of fungal laccases were used to isolate laccase gene-specific sequences froin a white rot rungus Ganodern~a lucidrm w-hich has been known to strengthen the imnnne system. A 1.6 Kbp fragment was amplified by PCR and its base sequence was detenuiued. Locating seven iutrous within the base sequence, we could deduce its amino acid sequence. The nucleotide sequence witl~out introlls was 47Y0 identical to that of lee1 gene of Pametes wllosa; lhe identity in amino acid sequences of the two was 7994 The deduced amino acid seqoence was also sunilar to those of Coriolus versicolo~ kc3 (79%); Co~,iolz~s hirsutus phenolouiduse (78%), Trainetes vel.srcoloi. lccl (77%), Trametes ~!i/Iosa Ice2 (77%) and Trametes vemicolor kc4 (66%).

• Korean Journal of Microbiology
• /
• v.42 no.1
• /
• pp.34-39
• /
• 2006

Wood-rot fungi produce extracellular lignin-degrading enzymes, the best known of which are lignin peroxidase, Mn-peroxidase and laccase. In this experiment, some of them produced all of three enzymes. Many other wood-rot fungi produced one or two of those enzymes with various combinations. In this experiment, we tried to clarify the relationship between the pattern of enzyme production and degradative activity of several dye compounds. From the 36 strains of 23 species of wood-rot fungi, Mn-peroxidase activity was found in 30 strains of the fungi tested, whereas the activity of lignin peroxidase and laccase was detected in 11 strains and 12 strains of species, repectively, in Kirks low nitrogen media. In relation to the activity of lignin degrading enzymes and degradation of dye compounds, the white-rot fungi with three kinds of enzymes tested showed the best dye decolorizers. The fungi with Mn-peroxidase activity only decolorized poly R-478 and remazol brilliant blue R dye in proportion to the enzyme activity, while methylene blue, bromophenol blue and congo red dye were degraded in regardless of enzyme activity. Those dyes were degraded in relation to the growth rate of mycelium. Brown-rot fungi did not degrade all the dye compounds except bromophenol blue, in spite of moderate growth rate.

• 보존과학연구
• /
• s.33
• /
• pp.99-108
• /
• 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.

• 보존과학연구
• /
• s.37
• /
• pp.5-15
• /
• 2016

We isolated microorganisms from soil arounding the stump and surface of stump in Bubjusa temple in Boeun, Heungguksa temple in Yeosu and Leeyongwoo house in Boseong. As a result, a distribution percentage of bacteria was high and there was a region-specific difference in bacteria colony. There was greater microbial diversity and population in the Leeyongwoo house in Boseong.

• Journal of Korean Society of Forest Science
• /
• v.108 no.1
• /
• pp.40-49
• /
• 2019

Coarse woody debris (CWD), which is a component of the forest ecosystem, plays a major role in forest energy flow and nutrient cycling. In particular, CWD isolates carbon for a long time and is important in terms of slowing the rate of carbon released from the forest to the atmosphere. Therefore, this study measured the physiochemical characteristics and respiration rate ($R_{CWD}$) of CWD for Larix kaempferi and Pinus rigida in temperate forests in central Korea. In summer 2018, CWD samples from decay class (DC) I to IV were collected in the 14 forest stands. $R_{CWD}$ and physiochemical characteristics were measured using a closed chamber with a portable carbon dioxide sensor in the laboratory. In both species, as CWD decomposition progressed, the density ($D_{CWD}$) of the CWD decreased while the water content ($WC_{CWD}$) increased. Furthermore, the carbon concentrations did not significantly differ by DC, whereas the nitrogen concentration significantly increased and the C/N ratio decreased. The respiration rate of L. kaempferi CWD increased significantly up to DC IV, but for P. rigida it increased to DC II and then unchanged for DC II-IV. Accordingly, except for carbon concentration, all the measured characteristics showed a significant correlation with $R_{CWD}$. Multiple linear regression showed that $WC_{CWD}$ was the most influential factor on $R_{CWD}$. $WC_{CWD}$ affects $R_{CWD}$ by increasing microbial activity and is closely related to complex environmental factors such as temperature and light conditions. Therefore, it is necessary to study their correlation and estimate the time-series pattern of CWD moisture.

• Journal of Forest and Environmental Science
• /
• v.13 no.1
• /
• pp.143-152
• /
• 1997

The decayed wood by Fomes pini (Thore) Lloyd required a smaller H factor than the sound wood for pulping to permanganate number 20. The H factors for the decayed wood pulping by the kraft and soda processes were reduced by 15% and 17%, respectively, in the presence of 1% anthraquinone. The wood components degraded by fungi are normally more readily solubilized in alkali than the corresponding components in sound wood. The nonphenolic ${\beta}$-O-4 type lignin model compound, veratrylglycerol-${\beta}$-guaiacyl ether(I), and phenolic model compound, syringylglycerol-${\beta}$-syringyl ether(III), were degraded by the white-rot fungi to yield ${\alpha}$-guaiacoxy-${\beta}$-hydroxypropioveratrone(II) from the former and ${\alpha}$-syringyloxy-${\beta}$-hydroxypropiosyringone(IV) from the latter. Structures of the degradation products indicated that C ${\alpha}$-oxidation could occur with white-rot fungi. It has been shown that the alkaline cleavage of ${\beta}$-aryl ether bonds in the lignin units is accelerated by the presence of ${\alpha}$-carbonyl groups.