• Journal of the Korean Wood Science and Technology
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• 제20권4호
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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.

• 펄프종이기술
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• 제36권5호
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• pp.69-77
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• 2004

Degradations of pine, yellow poplar and sweet gum by two fungi, Pycnoporus cinnabarinus and Trichophyton rubrum LSK-27 were investigated. P. cinabarinus degraded pine block samples much faster than T rub rum LSK-27, whereas P. cinnabarinus and T rubrum LSK-27 degraded yellow poplar and sweet gum at almost the same rate. In an effort to get a better understanding of how fungi degrade lignin in wood, contents of various functional groups were analyzed. After three-months of degradation of pine flour by these fungi, the following changes were observed: an increase in condensed phenolic OH group and carboxylic acid group content, a decrease in the guaiacyl phenolic OH content, and little change of aliphatic OH group content. Further studies in the degradation of pine flour by P. cinnabarinus indicated that the increase in condensed phenolic OH group content and the decrease in guaiacyl phenolic OH group content occurred in the first month of the degradation. The changes of functional group contents in the degradation of unbleached softwood kraft pulp by P. cinnabarinus had the same trends as those in the degradation of pine flour. That is, structural alteration of lignin due to the kraft pulping process had little effect on how P. cinnabarinus degraded lignin.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.422-430
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• 2000

Mechanism of lignin biodegradation caused by basidiomycetes and the history of lignin biodegradation studies were briefly reviewed. The important roles of fungal extracellular ligninolytic enzymes such as lignin and manganese peroxidases (LiP and MnP) were also summarized. These enzymes were unique in their catalytic mechanisms and substrate specificities. Either LiP or MnP system is capable of oxidizing a variety of aromatic substrates via a one-electron oxidation. Extracellular fungal system for aromatic degradation is non-specific, which recently attracts many people working a bioremediation field. On the other hand, an intracellular degradation system for aromatic compounds is rather specific in the fungal cell. Structurally similar compounds were prepared and metabolized, indicating that an intracellular degradation strategy consisted of the cellular systems for substrate recognition and metabolic response. It was assumed that lignin-degrading fungi might be needed to develop multiple metabolic pathways for a variety of aromatic compounds caused by the action of non-specific ligninolytic enzymes on lignin. Our recent results on chemical stress responsible factors analyzed using mRNA differential display techniques were also mentioned.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2009년도 춘계학술대회 및 임시총회
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• pp.53-55
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• 2009

• 임산에너지
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• 제17권1호
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• pp.56-70
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• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.

• Mycobiology
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• 제39권1호
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• pp.64-66
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• 2011

Most fungi possess several hydrogen peroxide-generating enzymes, glucose oxidase and pyranose oxidase. Pyranose oxidase can use glucose as its substrate to generate hydrogen peroxide. White rot fungi, which degrade diverse recalcitrant compounds, contain lignin-degrading enzymes, and lignin peroxidase and manganese peroxidase require hydrogen peroxide for their enzymatic reactions. In this study, we isolated a cDNA fragment of pyranose oxidase from Phlebia tremellosa using PCR and examined its expression under the degradation conditions of diethylphthalate (DEP). Pyranose oxidase expression was enhanced up to 30% by the addition of DEP, and this result supports the possible involvement of pyranose oxidase in the degradation of recalcitrant compounds.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.737-752
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• 2000

Wood-rotting basidiomycetous fungi are the most efficient degraders of lignin on earth. The white-rot fungus Phanerochaete chrysosporium has been used as a model microorganism in the study of enzymology and its application. Because of the ability of the white-rot fungus to degrade lignin, which has an irregular structure and large molecular mass, this fungus has also been studied in relation to degrading and mineralizing many environmental pollutants. The fungus includes an array of enzymes, such as lignin peroxidase (LiP), manganese-dependent peroxidase (MnP), cellobiose:quinone oxidoreductase, and $H_2O_2$-producing enzymes and also produces many other components of the ligninolytic system, such as veratryl alcohol (VA) and oxalate. In addition, the fungus has mechanisms for the reduction of degradation intermediates. The ligninolytic systems have been proved to provide reductive reactions as well as oxidative reactions, both of which are essential for the degradation of lignin and organopollutants. Further study on the white-rot fungus may provide many tools to both utilize lignin, the most abundant aromatic polymer, and bioremediate many recalcitrant organopollutants.

• 한국환경농학회지
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• 제25권3호
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• pp.211-216
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• 2006

Coriolus hirsutus LD-1 균주의 리그닌분해효소 활성과 몇몇 염료의 탈색능을 조사하였다. 백색부후균인 LD-1 균주는 laccase(16,388.9 U/L)와 manganese- dependent peroxidase (19.81 U/L)는 생산하였으나 lignin peroxidase를 생산하지 않았다. 균주를 염료와 함께 8일간 배양했을때 염료 RBBR과 염료 BB의 탈색율은 각각 70.2%와 98%로 나타났다. Manganese-dependent peroxidase는 8일간 배양 중 효소 활성은 매우 낮은 반면 laccase는 지속적으로 생산되어 대단히 높은 활성을 나타내었다. 백색부후균인 Coriolus hirsutus LD-1에 의한 염료의 탈색은 주로 laccase에 의한 것으로 사료되었다.

• Forest Science and Technology
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• 제13권4호
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• pp.158-163
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• 2017

We examined the activities of lignin-degrading enzymes of the mycelium of cauliflower mushroom (Sparassis latifolia). Three different strains of S. latifolia collected from several sites in Korea and one crossbred strain were cultured on potato dextrose broth (PDB) and Kirk's medium in order to study the activities of their ligninolytic enzymes. Mycelial growth reached maximum levels between 14 and 21 days after inoculation and pH increased by 0.12 units over 35 days. Laccase activity began increasing after 14 days on both types of media. Manganese peroxidase (MnP) activity followed a trend similar to that of laccase on Kirk's medium, but not on PDB. The activity of lignin peroxidase (LiP) differed from that of other enzymes; its activity decreased by half after 14 days on PDB but remained constant on Kirk's medium over 35 days. The total protein concentration increased considerably after 14 days and peaked at 21 days on PDB. A similar maximum was attained on Kirk's medium. In contrast, the residual glucose increased rapidly at 14 days on Kirk's medium, while increasing gradually up to 28 days on PDB. This study indicates that S. latifolia is more similar to white rot fungi than to other brown rot fungi.

• 보존과학연구
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• 통권30호
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• pp.157-170
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• 2009

We have evaluated the antifungal activities of oak vinegar to develop a natural biocide for organic cultural heritage. Fungi used in this study were screened from the cultural heritages, Kyujanggak and JanggyeongPanjeon and tested on organic substrates-degrading ability. In the results, 7 species of fungi have produced the extracellular enzymes to degrade CMC, xylan, lignin. Thus, we have used these seven species fungi to investigate the antifungal activity of oak vinegar in this study. In the result, the antifungal activity of oak vinegar indicated positive potencial. Especially, methylene chloride and ethylacetate fractions of the oak vinegar had high activities at the concentration of 5.0mg/disc. In these fractions, many different kinds of compounds such as phenolic and furfural, etc. were analyzed by GC-MS. The experiments indicated that the development of a biocide using natural extracts can have a potential to conserve of organic cultural heritages.