• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.211-216
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• 2006

The present research was undertaken to investigate the activities of ligninolytic enzymes and dye-decolorization capabilities of white-rotting fungi Coriolus hirsutus LD-1. The isolated white-rotting fungi (Coriolus hirsutus LD-1) produced laccase (16,388.9 U/L) and manganese-dependent peroxidase (19.81 U/L) but it did not produce lignin peroxidase. When the isolated fungi was incubated with the treatment of dyes for 8 days, the rates of decolorization of remazol brilliant blue R and bromophenol blue were 70.2% and 98%, respectively. The activity for manganese-dependent peroxidase was low, whereas that for laccase was very high. Moreover, the laccase was more effective to decolor when compared to manganese-dependent peroxidase. The results suggested that laccase of Coriolus hirsutus LD-1 might be playing an important role in the decolorization of the dyes.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1421-1430
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• 2009

With an aim to evaluate dye decolorization by white rot fungus on natural living conditions, reproducing by solid-state fermentation, the process of triphenylmethane dyes decolorization using the white rot fungus P. ostreatus BP, cultivated on rice straw solid-state medium, has been demonstrated. Three typical dyes, including malachite green, bromophenol blue, and crystal violet, were almost completely decolorized by the fungus after 9 days of incubation. During the process of dye decolorization, the activities of enzyme secreted by the fungus, and the contents of soluble components, such as phenolic compounds, protein, and sugar, changed regularly. The fungus could produce ligninolytic, cellulolytic, and hemicellulolytic enzymes and laccase was the most dominant enzyme in solid-state medium. Laccase, laccase isoenzyme, and the laccase mediator could explain the decolorization of malachite green, bromophenol blue, and crystal violet by the fungus in solid-state medium, respectively. It is worth noting that the presence of the water-soluble phenolic compounds could stimulate the growth of fungus, enhance the production of laccase, and accelerate dye decolorization.

• Journal of Microbiology
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• v.43 no.6
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• pp.555-560
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• 2005

Laccase is one of the ligninolytic enzymes of white rot fungus Trametes versicolor 951022, a strain first isolated in Korea. This laccase was purified 209-fold from culture fluid with a yield of $6.2\%$ using ethanol precipitation, DEAE-Sepharose, Phenyl-Sepharose, and Sephadex G-100 chromatography. T. versicolor 951022 excretes a single monomeric laccase showing a high specific activity of 91,443 U/mg for 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as a substrate. The enzyme has a molecular mass of approximately 97 kDa as determined by SDS-PAGE, which is larger than those of other laccases reported. It exhibits high enzyme activity over broad pH and temperature ranges with optimum activity at pH 3.0 and a temperature of $50^{\circ}C$. The $K_m$ value of the enzyme for substrate ABTS is $12.8{\mu}M$ and its corresponding $V_{max}$ value is 8125.4 U/mg. The specific activity and substrate affinity of this laccase are higher than those of other white rot fungi, therefore, it may be potentially useful for industrial purposes.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.43-48
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• 1997

여러가지 난분해성 물질에 대한 생분해능을 지닌 백색부후균에 의한 매립지 침출수의 탈색을 조사하였다. 국내에서 분리한 Coriolus versicolor KR-11W와 Irpex lacteus KR-39W가 이제까지 주로 연구되어 온 Phanerochaete chrysosporium보다 높은 탈색능을 나타내었는데 I. lacteus KR-39W는 산소공급시 10%의 침출수가 함유된 YMG 배지의 진탕배양에서 85%의 색도제거율을 나타내었으며 최소배지에서도 80%의 탈색율을 보였다. P. chrysosporium에 의한 리그닌 분해능 및 분해효소 생성 보고들과 달리 진탕배양이 정치배양보다 탈색능이 높았으며 산소공급은 색도제거에 증가효과가 있었다. 균체 접종량(10-30%)과 온도(25,37.deg. C)는 탈색에 큰 차이를 보이지 않았으나 탄소원과 질소원의 농도는 상당한 영향을 나타내었다. 리그닌 분해효소군의 여러 가지 inducer와 cofactor를 C. versicolor KR-11W 배양에 첨가한 결과 많은 경우 균접종 대조군보다 2배 이상의 탈색율과 lignin peroxidase 활성의 증가를 보였으며 FeS $O_{5}$ 첨가시에는 최대 2.9배의 증가를 나타내었다. 탈색에 관여하는 효소군은 접종물에 이미 어느 정도 존재할 수 있으며 배지 및 배양조건에 따라 그 생성이 변화할 수 있으므로 이런 조건들을 잘 맞출 경우 보다 높은 탈색능이 기대된다.

• Journal of Mushroom
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• v.10 no.2
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• pp.74-82
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• 2012

Sixty strains of Pleurotus ostreatus, white-rot fungi, were screened for production ability of their lignocellulolytic enzymes to selectively wood degradation. That results were shown that all of screened strains were produced lignocellulolytic enzymes on 2nd screening liquid culture medium. However, cellulase activity of selected six strains of P. ostreatus was low in avicel-yeast-peptone liquid culture medium. In the case of xylan degrading enzyme, No. 6 and No. 38 strains produced a xylanase(above 1.0U/ml) and a 1,4-${\beta}$-xylosidase (above 0.15 U/ml). Examination of the ligninolytic enzyme profiles of selected thirteen strains of the P. ostreatus, in the presence of Remazol Brilliant Blue R(RBBR), were observed that laccase(Lac) activity were earlier reached maximum level(0.8-2.0 U/ml) and then Mn-dependent peroxidase (MnP) were reached maximum level(0.5-1.5 U/ml) in glucose-yeast-peptone(GYP) medium. On the other hand, activity of lignin peroxidase(LiP) was not detected in this medium. I selected the No. 42 strain of P. ostreatus produced high levels of Mn-dependent peroxidase and laccase based on the screening method.

• Journal of Korea Foresty Energy
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• v.17 no.1
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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.

• Journal of Mushroom
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• v.20 no.2
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• pp.86-91
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• 2022

Pleurotus eryngii, a white rot fungus, produces two extracellular lignin-degrading enzymes, laccase and manganese peroxidase (MnP). Owing to these enzymes, P. eryngii efficiently degrades synthetic chemicals such as azo, phthalocyanine, and triphenyl methane dyes. In this study, we investigated the degradation processes of four aromatic dyes, congo red (CR), methylene blue (MB), crystal violet (CV), and malachite green (MG), by P. eryngii under solid and liquid culture conditions. CR and MG were the most quickly degraded under solid and liquid culture conditions, respectively. However, compared to CR, CV, and MG, MB was not degraded well under both culture conditions. The activities of ligninolytic enzymes (laccase and MnP) were also investigated. Laccase was identified to be the major enzyme for dye degradation. A positive relationship between decolorization and enzyme activity was observed for CR, MB, and CV degradation. In contrast, decolorization of MG ensued after high enzyme activity. These results indicate that the degradation process differs between MG and the other aromatic dyes. Therefore, P. eryngii could be a potential tool for the bioremediation of synthetic aromatic dye effluent.

• Clean Technology
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• v.10 no.3
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• pp.131-137
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• 2004

Due to the low biodegradability of dyes, conventional biological wastewater treatment systems are inefficient in treating textile wastewater. In this study, white rot fungus, Trametes versicolor KCTC 16781, were investigated for the decolorization of Reactive black 5 solutions. This fungus was able to degrade the dye solutions by the ligninolytic enzymes (laccase and MnP) produced. The enzyme activity remained constant until the end of reaction. The combined process of biological treatment and ceramic membrane showed better efficiency for decolorization and TOC removal than each single process.

• Mycobiology
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• v.44 no.4
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• pp.260-268
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• 2016

Regulation of alkaline-resistant laccase from Perenniporia tephropora KU-Alk4 was proved to be controlled by several factors. One important factor was the initial pH, which drove the fungus to produce different kinds of ligninolytic enzymes. P. tephropora KU-Alk4 could grow at pH 4.5, 7.0, and 8.0. The fungus produced laccase and MnP at pH 7.0, but only laccase at pH 8.0. The specific activity of laccase in the pH 8.0 culture was higher than that in the pH 7.0 culture. At pH 8.0, glucose was the best carbon source for laccase production but growth was better with lactose. Low concentrations of glucose at 0.1% to 1.0% enhanced laccase production, while concentrations over 1% gave contradictory results. Veratryl alcohol induced the production of laccase. A trace concentration of copper ions was required for laccase production. Biomass increased with an increasing rate of aeration of shaking flasks from 100 to 140 rpm; however, shaking at over 120 rpm decreased laccase quantity. Highest amount of laccase produced by KU-Alk4, 360 U/mL, was at pH 8.0 with 1% glucose and 0.2 mM copper sulfate, unshaken for the first 3 days, followed by addition of 0.85 mM veratryl alcohol and shaking at 120 rpm. The crude enzyme was significantly stable in alkaline pH 8.0~10.0 for 24 hr. After treating the pulp mill effluent with the KU-Alk4 system for 3 days, pH decreased from 9.6 to 6.8, with reduction of color and chemical oxygen demand at 83.2% and 81%, respectively. Laccase was detectable during the biotreatment process.

• Journal of Mushroom
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• v.16 no.4
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• pp.272-278
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• 2018

Lignin degrading enzymes from Lentinula edodes have broad substrate specificities, and therefore can degrade a variety of recalcitrant compounds. In this study, the lignolytic biodegradation was investigated in five different L. edodes fungi (Chunbaegko, Sanjo 303ho, Poongnyunko, Baekhwahyang, and Soohyangko). The fungi were evaluated for their ability to decolorize Remazol Brilliant Blue R (RBBR) in malt extract broth medium. Sanjo 303ho, Poongnyunko, Baekhwahyang, and Soohyangko rapidly decolorized RBBR within 7 days. The activities of manganese peroxidase (MnP) and laccase were determined in the absence and presence of lignin. Poongnyunko displayed the highest ligninolytic activity on day 7 of incubation (2,809 U/mg and 2,230 U/mg for MnP and laccase, respectively).