• Title, Summary, Keyword: Laccase activity

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Enzymatic Characteristics of Laccase from White Rot Fungus, Flammulina velutipes (백색부후균(白色腐朽菌) Flammulina velutipes로 부터 추출(抽出)한 리그닌 분해효소(分解酵素)의 효소적(酵素的) 특성(特性))

  • Suh, Dal-Sun;Lee, Jae-Sung;Cho, Nam-Seok
    • Journal of the Korean Wood Science and Technology
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    • v.14 no.3
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    • pp.36-42
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    • 1986
  • The production media and the enzymatic charateristics of laccase from Flammulina velutipes were investigated. The activity of laccase during incubation reached to the maximum at the 40 days of incubation in the case of Barley straw medium. The maximum laccase activity in Barley straw medium was 5 and 16 times higher than those in Onion basic and Sawdust media, respectively. The laccase from Flammulina velutipes has the optimum pH of 6.6 and showed to be stable at relatively broad pH range. 4.5-9.5. Temperature stability showed that above 96% activity could be preserved after holding at 40$^{\circ}C$ for 40 minutes. At the above 70$^{\circ}C$, the laccase activity decreased very rapidly. The Km value of the laccase was estimated to be 28.0 mM which is much higher than that of the laccase from Pleurotus ostreatus. Organic solvents for precipitiation of the enzyme did not inactivation the laccase. Sodium azide which was added for preventing microbial deterioration affected significantly the inactivation of laccase, but this activity was recovered completely by precipitating the enzyme with acetone.

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An Immobilization of Extracellular Laccase to Humus-Iron Complex

  • Ginalska, Grazyna;Cho, Nam-Seok;Lobarzewski, Jerzy;Piccolo, Alessandro;Leonowicz, Andrzej
    • Journal of the Korean Wood Science and Technology
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    • v.29 no.3
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    • pp.104-111
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    • 2001
  • There are some evidence that active enzymatic proteins, e.g. fungal laccase, exist in the naturally occured soil humus. This study was performed to investigate the covalent binding of fungal laccase to the humic acid-iron complex, and to measure laccase activity of immobilized ones. Seven methods were adopted to form the covalent binding of fungal laccase with soil humic acids complexed with iron. Using these seven methods it was possible to change the dimension of spacer arm between laccase and support, and also to regulate the mode of covalent binding of this enzyme. The spacer arm was regulated from 2C to 11C. There was not observed any straight relationship between the spacer arm longitude and the laccase activity after immobilization, but the binding mode more effective than the former. Three out of the seven methods gave the high activity of immobilized laccase, and which active products of laccase immobilization was stable up to 10 days after the process. It is indicated that natural soil condition might be prevented the laccase activation by the toxic influence of some phenolic humic compounds. It was shown, for the first time, the possibilities to obtain the high activity of fungal laccase by binding to humic acids, and especially in complex with iron.

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Effect of Supplements $Mn^{2+}$, $Cu^{2+}$, and Aromatic Compounds and Penicillium decumbens on Lignocellulosic Enzyme Activity and Productivity of Catathelasma ventricosum

  • Liu, Yuntao;Sun, Jun;Luo, Zeyu;Rao, Shengqi;Su, Yujie;Yang, Yanjun
    • Journal of Microbiology and Biotechnology
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    • v.23 no.4
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    • pp.565-571
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    • 2013
  • This is the first report on using Catathelasma ventricosum for production of fruiting body and lignocellulosic enzymes. To improve the laccase activity and productivity of mushroom, the substrate was added with different supplements (eight aromatic compounds, $Mn^{2+}$, and $Cu^{2+}$). Based on the results, all these supplements can improve the laccase activity and productivity of C. ventricosum, and it seems that there is a critical value of laccase activity that affects the productivity of C. ventricosum. In addition, when Penicillium decumbens was inoculated into the substrate that had been cultivated with C. ventricosum for 20 days, the highest values of laccase activity, FPA activity, and productivity of C. ventricosum were obtained. Moreover, the laccase activity showed a positive correlation with the productivity of C. ventricosum. Finally, the effect of $Mn^{2+}$, $Cu^{2+}$, and P. decumbens on laccase activity was investigated by response surface methodology (RSM).

A New Detergentless Micro-Emulsion System Using Urushiol as an Enzyme Reaction System

  • Kim, John-Woo-Shik;Yoo, Young-Je
    • Journal of Microbiology and Biotechnology
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    • v.11 no.3
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    • pp.369-375
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    • 2001
  • Urushiol, a natural monomeric oil, was used to prepare a detergentless micro-emulsion with water and 2-propanol The formation of micro-emulsion was verified by conductivity measurements and dynamic light scattering. The conductivity data showed phase change dynamics, a characteristics of micro-emulsions, and subsequent dynamic light scattering study further confirmed the phenomenon. Average water droplet diameter was 10 nm to 500 nm when the molar ratio of 2-propanol ranged from 0.40 to 0.44 . Earlier studies were performed on toluene and hexane, in which the insoluble substrate in water phase was added to the solvents to be reacted on by enzymes. However, in the present urushiol system, urushiol was used as both solvent and substrate in the laccase polymerization of urushiol. The laccase activity in the system was examined using polymerization of urushiol. The laccase activity in the system was examined using syringaldezine as a substrate, and the activity increased rapidly near the molar ratio of 2-propanol at 0.4, where micro-emulsion started. The activity rose until 0.46 and fell dramatically thereafter. The study of laccase activity in differing mole fractions of 2-propanol showed the existence of an ‘optimal zone’, where the activity of laccase was significantly higher. In order to analyze urushiol polymerization by laccase, a bubble column reactor using a detergentless micro-emulsion system was constructed. Comparative study using other organic solvents systems were conducted and the 2-propanol system was shown to yield the highest polymerization level. The study of laccase activity at a differing mole fraction of 2-propanol showed the existence of an ‘optimal zone’ where the activity was significantly higher. Also, 3,000 cP viscosity was achieved in actual urushi processing, using only 1/100 level of laccase present in urushi.

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Optimizing Culture Conditions to Maximize the Production of Laccase from Pholiota highlandensis (Pholiota highlandensis 유래 laccase 생산을 위한 배양조건의 최적화)

  • Choi, Hye-Ju;Moon, Soo-Jung;Jeon, Sung-Jong
    • Journal of Life Science
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    • v.25 no.6
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    • pp.673-679
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    • 2015
  • The culture conditions needed to maximize the production of laccase from Pholiota highlandensis mycelia were investigated. Among the tested media for laccase production, Coriolus versicolor medium (CVM; 2% dextrose, 0.4% peptone, 0.6% yeast extract, 0.046% KH2PO4, 0.1% K2HPO4, 0.05% MgSO4·7H2O) showed the highest activity for the enzyme. Then, to optimize culture conditions for laccase activity, the influences of various carbon, nitrogen, phosphorus, and inorganic salt sources in CVM were investigated. The optimum culture medium was 2% fructose, 0.4% peptone with 0.6% yeast extract, 0.05% NaH2PO4, and 0.05% MgSO4·7H2O as carbon, nitrogen, phosphorus, and inorganic salt sources, respectively. Several aromatic compounds in the medium enhanced laccase activity to varying degrees. Guaiacol induced maximum laccase production, yielding 114.1 U/ml laccase activity after cultivation for 11 days at 25℃. The optimum pH and temperature for laccase production were 8.0 and 35℃, respectively. Native polyacrylamide-gel electrophoresis (PAGE) followed by laccase-activity staining with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the substrate was performed to identify the presence of laccase under the optimum conditions studied. Zymogram analysis of the supernatant culture showed an enzymatic band with a molecular mass of about 90 kDa.

Cloning and expression of new laccase gene (soncotA) from Bacillus sonorensis KCTC13918 in E. coli (Bacillus sonorensis KCTC13918로부터 새로운 laccase유전자 (soncotA)의 클로닝과 대장균에서의 발현)

  • Choi, Shin-Geon;Yoon, Hyeonjong
    • Journal of Industrial Technology
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    • v.37 no.1
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    • pp.16-20
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    • 2017
  • A new putative laccase gene (soncotA) which show 78% homology with that from Bacillus licheniformis (liccotA) was isolated from draft genome sequence of Bacillus sonorensis KCTC 13918. A 1,545 bp of PCR product corresponding 514 amino acids was cloned into NdeI-NotI site of pET21c and expressed as soluble form in E. coli. About 59 kDa size of recombinant laccase was purified into homogenity by Ni-NTA column and laccase activity was confirmed by zymography. The enzymatic properties of recombinant laccase were characterized. The specific activity of B. sonorensis laccase was 0.033 fold lower than that of Bacillus licheniformis laccase. The finding of new laccase gene broadened the enzymatic diversity of Bacillus species laccases.

Enhancement of Laccase Production from Wood-Rotting Fungus by Co-Culture with Trichoderma longibrachiatum

  • Jung, Hyun-Chae
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.2
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    • pp.210-220
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    • 2019
  • This work aimed to evaluate the influence of culture conditions on laccase production in the co-culture of wood-rotting fungus with Trichoderma sp. The effects of infection extent, infection time, and culture filtrate of Trichoderma sp. on the laccase production by wood-rotting fungus in co-culture were examined. T. rubrum LKY-7 and T. longibrachiatum were selected as fungi which are effective in co-culture for laccase production. A significant increase in laccase activity was observed when T. rubrum LKY-7 was co-cultured with T. longibrachiatum in glucose-peptone liquid medium, yielding an increase of more than 5 times in laccase activity, as compared with control. Laccase production by T. rubrum LKY-7 during co-culturing was significantly influenced by the infection extent and the infection time of T. longibrachiatum. Maximal laccase activity was obtained when T. rubrum LKY-7 culture was infected by T. longibrachiatum after 3 days of cultivation at an inoculum size ratio of 0.5 to 1. The addition of culture filtrate or autoclaved mycelium of T. longibrachiatum to T. rubrum LKY-7 culture did not significantly enhance laccase production by T. rubrum LKY-7 as compared with control (mono cultures of T. rubrum LKY-7).

Production, Partial Purification and Physico-Chemical Characteristics of Laccase from Pleurotus ostreatus (Pleurotus ostreatus가 생산하는 Laccase의 부분정제 및 효소적 특성)

  • Lee, Jae Sung;Lee, Un Jung;Suh, Dal Sun
    • Microbiology and Biotechnology Letters
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    • v.13 no.1
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    • pp.65-70
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    • 1985
  • The production media, partial purification and the enzymatic characteristics of laccase from Pleurotus ostreatus were investigated. Among various media tried the double strength onion media showed much higher production of laccase compared to glucose and/or CMC added media. The laccase from Pleurotus ostreatus has the optimum pH of 5.94 for the activity and appears to be stable at relatively broad pH spectrum (4.7-8.7). The experiments on the temperature stability shows that above 90% activity could be preserved after holding at $30^{\circ}C$ for 40 min., 60% activity was remained after 40 min. at $50^{\circ}C$. The Km value of the laccase from Pleurotus ostreatus was estimated to be 3.209mM and the molecular weight of laccase was estimated to be 55,000 by SDS-Polyacrylamide gel electrophoresis.

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Screening of New Mediators for Lignin Degradation Based on Their Electrochemical Properties and Interactions with Fungal Laccase

  • Shin, Woon-Sup;Cho, Hee-Yeon;Cho, Nam-Seok
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.5
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    • pp.1-8
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    • 2006
  • This study was performed to evaluate extensive electrochemical characteristics of 23 commercially available mediators for laccase. Electrochemical properties, interactions with laccases, and ability to degrade lignin were compared for selected mediators. Among them, NNDS has very similar electrochemical properties in terms of reversibility and redox potential (about 470 mV vs. Ag/AgCl at pH=7) compared to ABTS which is a well-known mediator. Specific activity of purified laccase from Cerrena unicolor was determined by both 2,2'-azino-bis-(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) and 1-nitroso-2-naphthol -3,6-disulfonic acid (NNDS). The specific activity of the laccase was 23.2 units/mg with ABTS and 21.2 units/mg with NNDS. The electron exchange rate for NNDS with laccase was very similar to that for ABTS, which meant that NNDS had similar mediating capability to ABTS. Determining methanol concentration after reacting with laccase compared to lignin degradation capabilities of both ARTS and NNDS. ARTS or NNDS alone cannot degrade lignin, but in the presence of laccase enhanced the rate of lignin degradation. ABTS showed better activity in the beginning, and the reaction rate of NNDS with lignin was about a half of that of ABTS at 10 minute, but the final concentration of methanol produced in 1 hour was very similar each other. The reason for similar methanol concentration for both ABTS and NNDS can be interpreted as the initial activity of ABTS was better than that of NNDS, but ABTS would be inhibited laccase activity more during the incubation.

Induction of Laccase from Wood-Rotting Fungi with 2,5-Xylidine (2,5-Xylidine을 이용한 목재부후균으로부터 Laccase 효소의 유도)

  • Cho, Nam-Seok;Kim, Y.S.;Pang, M.H.;Choi, Y.J.;Nam, J.H.;Leonowicz, A.
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.3
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    • pp.41-47
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    • 1998
  • Some white-rot fungi, screened at the Laboratory of Forest Products Microbiological Chemistry, Chungbuk National University were cultured and added the inducer of laccase enzyme, 2,5-xylidine. The fungi named by CB-13, CB-20, CB-99, CB-100 and CB-123 strains showed positive results in the decolorization of aromatic compounds, carminic acid and Rhemazol brilliant blue R. Concerned to the inducing effect of 2,5-xylidine on laccase activity, CB-20, CB-100 and CB-123 strains showed very high activity by addition of 2,5-xylidine, whilst CB-13, CB-99 and CB-124 strains produced relatively high laccase enzymes, regardless of inducer addition. There were no any laccase activities on CB-25, CB-64 and CB-139, even in addition of inducer. It is confirmed that some screened fungi have decolorizing ability on aromatic compounds, carminic acid and Rhemazol brilliant blue R. Also, the addition of inducer, 2,5-xylidine, has increased the activity of laccase enzyme which is secreted from some white-rot fungi.

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