• 펄프종이기술
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• 제31권5호
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• pp.1-11
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• 1999

Wood components, cellulose and lignin, are degraded simultaneously and the general outline for the complementary character of carbohydrates and lignin decomposition as well as the existence of enzymatic systems combining these processes is still valid. The degradatiion of free cellulose or hemicellulose into monosaccharides has long been known to be relatively simple, but the mechanism of lignin degradatiion wasn ot solved very clearly yet. Anyway the biodegradation of woold constituents is understood at present as an enzymatic process. Kigninolytic activity has been correlated with lignin and manganese peroxidases. At present the attention is paid to laccase. Laccase oxidizes lignin molecule to phenoxy radicals and quinones . This oxidation can lead to the cleavageo f C-C or C-O bonds in the lignin phenyl-propane subunits, resulting either in degradation of both side chains and aromatic rings, or in demethylation processes. The role of laccase lies in the "activation" of some low molecular weight mediators and radicals produced by fungal cultures. Such activated factors produced also in cooperation with other enzymes are probably exported to the wood environment where they work in degradation processes as the ' enzyme messengers." It is worth mentioning that only fungi possessing laccase show demethylating activity. Thus demethylation, the process important for ligninolysis, is probably caused exclusively by laccase. Under natural conditions laccase seems to work with other fungal enzymes , mediators and mediating radicals. It has shown the possibility of direct Bjrkman lignin depolymerization by cooperative activity of laccase and glucose oxidase.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1765-1773
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• 2016

Wastewater containing kraft lignin (KL) discharged from pulp and paper industries could cause serious environmental contamination. Appropriate effluent treatment is required to reduce the pollution. Investigations on anaerobic bacteria capable of degrading KL are beneficial to both lignin removal and biofuel regeneration from the effluent. In this paper, an anaerobic strain capable of degrading KL was isolated from the sludge of a pulp and paper mill and identified as Dysgonomonas sp. WJDL-Y1 by 16S rRNA analysis. Optimum conditions for KL degradation by strain WJDL-Y1 were obtained at initial pH of 6.8, C:N ratio of 6 and temperature of 33℃, based on statistical analyses by response surface methodology. For a 1.2 g/l KL solution, a COD removal rate of 20.7% concomitant with biomass increase of 17.6% was achieved after 4 days of incubation under the optimum conditions. After the treatment by strain WJDL-Y1, KL was modified and degraded.

• Journal of Forest and Environmental Science
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• 제12권1호
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• pp.37-44
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• 1996

Veratrylglycerol-${\beta}$-vanillylalcohol ether 결합 (${\beta}$-O-4 linkage)을 갖는 이양체(二量體) 리그닌 모델화합물(化合物)의 합성(合成)하여 각종 리그닌 반응(反應)의 시료(試料)로서 활용(活用)하고자 3,5-dimethoxyacetophenone을 출발물질(出發物質)로 하여 ${\beta}$-ring에 측소(側銷)를 갖는 이양체(二量體) 리그닌 모델화합물(化合物)(I-IV)을 합성(合成)하였고, 융점측정, $^1H(^{13}C)$-NMR 및 Mass 스펙트라에 의하여 그 화학구조(化學構造)를 동정(同定)하였다. 이 합성화합물(合成化合物)중에서 1-(3,4-dimethoxyphenyl)-2-(2'-methoxy-4'-hydroxymethylphenoxy)ropanediol-1,3[IV]는 매우 중요한 리그닌 이양체(二量體) 화합물(化合物)이다. 이러한 리그닌 합성연구(合成硏究)는 기초적(基礎的)인 연구(硏究)의 중요성(重要性) 뿐만아니라 응용면(應用面)에서도 그 활용도(活用度)가 높을 것이다.

• 한국의류학회지
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• 제41권3호
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• pp.517-526
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• 2017

The biodegradation and water absorption properties of lignin/poly(vinyl alcohol) (PVA) nanofibrous webs are investigated. Lignin/PVA nanofibrous webs containing 0, 50, and 85wt% of lignin were prepared via an electrospinning process to observe the effect of the lignin concentration on the biodegradability and water absorption properties of lignin/PVA nanofibrous webs. The morphology of the materials was examined by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). To understand the wetting behavior and hydrophilic nature of the electrospun lignin/PVA nanofibrous webs, the water absorbency, contact angle, and water uptake were examined. The enzymatic degradation of lignin/PVA nanofibrous webs was investigated using laccase by measuring total organic carbon (TOC) concentration over a course of 50 days. Water drops were absorbed immediately into all of the specimens. The water uptake of lignin/PVA nanofibrous webs increased as the amount of PVA in the lignin/PVA hybrid webs increased. The enzymatic degradation experiment indicated that the inherent biodegradability of lignin was retained after its transformation into nanofibers. Our findings imply that blending these two types of polymers is promising because it can lead to the development of a new range of multifunctional materials such as antimicrobial absorbent nanotextiles based on sustainable biopolymers.

• 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.

• 미생물학회지
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• 제22권2호
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• pp.97-101
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• 1984

To investigate the biodegradation pattern of rice straw, mainly composed of cellulose, hemicellulose and lignin components, by the isolate stran Bacillus subtilis $DO_4$, the change of cell population was observed on CMC (carboxymethyl cellulose), larch wood xylan and lignosulfonate as a carbon source respectively. Also, the transition pattern of enzyme activities of cellulase and xylanase and lignin contents was measured on rice straw and mixed substrate according to growth. The results in these experiments revealed that xylanase activity was first appeared and cellulase activity in the next, while lignin component was almost not changed through the culture period.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권3호
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• pp.211-214
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• 2000

The roles of lignin peroxidase, manganese peroxidase, and laccase were inverstigated in the biodegration of pentachlorphenol (PCP) by several which rot fungi. The disappearance of pentachlorophenol from cultures of wild type strains, P. chrysosporium, Trametes sp. and of pentachlorophenol from cultures of wild type strains, P. cheysocporium, Trametes sp. and Pleurotus ap., was observed. The activities of mangnese peroxidase and laccase was detected in Trametes sp. and pleurotus sp. cultures. However, the activities showed that PCP was degraded under ligninolytic as well as nonligninoytic condicationg that lignin peroxidase, manganese peroxidase, and laccase are not essential in the biodegradation of PCP by white rot fungi.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.759-763
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• 2000

Cell-free culture broth of Phanerochaete chrysosporium has been adopted to biologically degrade 2,4,5-trichlorophenol. Two different medium compositions of nitrogen-sufficient and nitrogen-limited were compared for their distribution of isozymes, activity of lignin peroxidase, and production of oxalate. The two different culture broths were tested for their ability to degrade 2,4,5-trichlorophenol, and the biodegradation efficiency was estimated in terms of the disappearance of 2,4,5-trichlorophenol. The degradation efficiency for the nitrogen-limited culture broth was higher than that of the nitrogen-sufficient culture broth, since the nitrogen-limited culture broth induced lignin peroxidases (LiPs) and manganese peroxidases (MnPs), and contained sufficient oxalate for producing necessary radicals. Finally, the possible mechanism of 2,4,5-CP degradation using the nitrogen-limited culture broth was proposed.

• Journal of the Korean Wood Science and Technology
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• 제41권1호
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• pp.19-32
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• 2013

본 연구에서는 백색부후균의 리그닌 분해 효소 시스템을 이용하여, 다양한 균주 중에서 목질계 바이오매스 유기용매 전처리 과정에서 발생한 리그닌(유기용매 리그닌)의 생분해에 적합한 우수 균주를 선별하고자 하였다. 우선 분양받은 15개의 백색부후균을 대상으로 shallow stationary cultur (SSC)배지와 malt extract broth (MEB)배지에 유기용매 리그닌의 첨가에 따른 Remazol Brilliant Blue R (RBBR)의 흡광도 변화를 측정하였다. RBBR 탈색능 결과, SSC 배지에서 Ceriporiopsis subvermispora, Ceriporia lacerate, Fomitopsis insularis, Phanerochaete chrysosporium, Polyporus brumalis, Stereum hirsutum 등 6종의 백색부후균에서 급격한 흡광도 변화를 나타냈다. 배양 초기에 급격한 흡광도 변화를 나타낸 6개의 백색부후균을 대상으로 균체 외 단백질 농도 및 리그닌 분해 효소 활성을 측정하였다. 선발된 6개의 균 중에서 S. hirsutum과 P. chrysosporium은 유기용매 리그닌을 첨가한 실험구에서 높은 단백질 농도가 측정되었다. 반면, 리그닌 분해 효소 활성은 F. insularis에서 배양 6일째에 manganese peroxidase (MnP) 활성이 1,545 U/mg, laccase 활성은 1,259 U/mg으로 최고 활성을 나타냈다. 결론적으로, 균체 외 단백질 농도 및 리그닌 분해 효소 활성이 전반적으로 높았던 $STH^*$와 MnP 및 laccase의 활성이 가장 높은 FOI가 유기용매 리그닌 생분해에 유리하게 작용할 것으로 판단된다.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.287-292
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• 2002

본 연구에서는 경안천 유역에 있는 주유소 오염토양으로부터 대표적인 아조계 염료 congo-red분해능이 우수한 토양 방선균, SMA-2를 분리 선별하고, SMA-2의 배양조건을 최적화하여 2,4-dichlorophenol의 산화에 관여하는 actinomycetes lignin peroxidase(ALiP)의 활성도에 대한 특성을 규명하였다. 기존에 보고된 방선균 유래 ALiP와는 달리, SMA-2유래 ALiP효소는 pH6에서 최고의 활성을 보였으며, 2,4-DCP와 $H_2$$O_2$에 대한 Km값이 각각 0.21mM과 8.5mM로 측정되었다. 또한 최적화된 배지에서 성장한 SMA-2의 배양액은 2,4-dichlorophenol 뿐만 아니라 2-chlorophenol, 2,4,6-trichlorophenol, 2,6-dichlorophenol, phenol, 4-chloropheno떼 대해서도 산화능을 보임으로써, 토양 방선균을 이용한 염화 페놀계 화합물이 포함된 오염 토양의 생복원 가능성을 제시하였다.