• 한국미생물·생명공학회지
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• 제48권4호
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• pp.463-470
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• 2020

삼림지역의 고목에서 분리한 JS18 균주는 합성 멜라닌을 탈색하는 세포 외 분비효소를 생산했다. JS18 균주의 internal transcribed spacer (ITS) 염기서열을 분석하고 계통학적으로 확인한 결과 본 균주는 Trametes velutina로 동정되었다. JS18 균주는 laccase 활성을 나타냈지만 manganese peroxidase 및 lignin peroxidase 활성은 나타내지 않았다. 본 균주를 회분배양한 결과 멜라닌 탈색 활성은 laccase 활성으로부터 유래하는 것으로 확인되었다. Laccase 유도인자로써 Syringic acid 및 CuSO4를 첨가하고 25℃에서 7일간 배양한 결과 배양상등액에서 98 U/ml의 laccase 활성을 나타내었다. GYP 배지에서 배양한 T. velutina의 배양상등액에서 ammonium sulfate 침전, Hi-trap Q Sepharose 컬럼 및 gel filtration을 이용하여 효소를 정제하였고, SDS-PAGE에서 약 67 kDa의 분자량을 나타내었다. 정제된 효소의 멜라닌 탈색율은 효소 단독으로는 24 시간 만에 단지 4% 만을 나타내는 반면, HBT의 존재 하에서는 80%로 향상되었다. 또한 1.5 mM HBT의 농도에서는 최대 81%의 멜라닌 탈색율을 나타내었다. 본 효소의 멜라닌 탈색에 대한 최적 pH 및 온도는 각각 5.0와 37℃를 나타내었다. 본 연구에서는 T. velutina JS18 유래 laccase가 촉매하는 멜라닌 탈색 반응에서 redox mediator로써 HBT의 적용 가능성을 확인하였다.

• 한국균학회지
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• 제22권3호
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• pp.254-259
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• 1994

P. chrysosporium BKM-F-1767 및 C. subvermispora FP90031-SP. 균사를 이용하여 ligninase와 laccase 활성제고를 위한 배앙방법을 검토한 결과는 다음과 같다. P. chrysosporium의 왕복진탕배양시 (150 rpm) 배양액량은 45-60 ml가 ligninase 활성제고에 적합하였으며 60 ml 배양은 최대활성 출현일이 빨리 나타났다. C. subvermispora의 정치배양시, 2% M.E.+0.1% Y.E.+0.1% T.W.20+1mMVA 처리에서 ligninase 활성이 가장 높았고 laccase의 활성은 2% M.E.+0.1% Y.E.+0.1% T.W.20+6 mMBA에서 최고 수준을 나타내었다.

• Journal of the Korean Wood Science and Technology
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• 제35권4호
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• pp.61-66
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• 2007

본 연구에서는 trametes versicolor에서 분비하는 laccase를 분리 정제하고, 그 효소특성을 조사하였다. 공시균의 배지로는 PDB배지를 사용하였으며, 이 효소를 유도하기 위하여 공시균 접종 5일 후 inducer로 2,5-xylidine (0.2 mM)을 첨가하였다. Inducer 첨가 2일 후 laccase를 수확하여 Glass filter (GF/C)를 이용하여 균사체를 제거한 후 laccase 여과액의 정제시간을 단축시키고, 쉽게 단백질을 농축시키기 위하여 ultramicrofilter (Viva flow 50, GE Healthcare Bioscience, USA)를 사용하여 농축하였다. 이렇게 농축된 laccase 여과액은 Hitrap Q FF column으로 부분 정제하여 활성이 검출된 peak를 확인할 수 있었다. 효소의 특성을 조사한 결과 효소의 활성이 가장 높은 pH는 5.0이었으며 최적 온도는 $60^{\circ}C$였고, specific activity는 syringaldazine을 substrate로 사용하여 확인한 결과 crude한 상태에서는 약 32 U/mg였고, 농축한 후에는 약 409 U/mg였으며 Hitrap Q FF column으로 분리한 후에는 약 1.243 U/mg였다. 그리고 SDS-PAGE gel 사진으로 확인한 결과 단백질의 크기는 약 53 kDa이었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권5호
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• pp.294-298
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• 2003

Endocrine-disrupting phenolic compounds in the water were degraded by laccase from Trametes sp. followed by activated sludge treatment. The effect of temperature on the degradation of phenolic compounds and the production of organic compounds were investigated using endocrine-disrupting chemicals such as bisphenol A, 2.4-dichlorophenol, and diethyl phthalate. Bisphenol A and 2.4-dichlorophenol disappeared completely after the laccase treatment, but no disappearance of diethyl phthalate was observed. The Michaelis-Menten type equation was proposed to represent the degradation rate of bisphenol A by the lacasse under various temperatures. After the laccase treatment of endocrine-disrupting chemicals, the activated sludge treatment was attempted and it could convert about 85 and 75% of organic compounds produced from bisphenol A and 2.4-dichlorophenol into H$_2$O and CO$_2$, respectively.

• Journal of Microbiology and Biotechnology
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• 제23권4호
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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).

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.207-214
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• 2012

Laccase- and peroxidase-free tyrosinase has commercial importance in the production of L-3, 4-dihydroxyphenylalanine (L-DOPA), which is mainly used in the treatment of Parkinson's disease. In the present study, isolation of an actinomycetes microbial strain capable of producing only tyrosinase is reported. Among all soil isolates, three individual colonies revealed black color around the colony in the presence of tyrosine. Further screening for laccase and peroxidase activities using syringaldazine denoted that one of the isolates, designated as RSP-T1, is laccase and peroxidase negative and produces only tyrosinase. The microbe was authenticated as Streptomyces antibioticus based on 16S ribotyping. Effective growth of this isolate was noticed with the use of medium (pH 5.5) containing casein acid hydrolysate (10.0 g/l), $K_2HPO_4$ (5.0 g/l), $MgSO_4$ (0.25 g/l), L-tyrosine (1.0 g/l), and agar (15 g/l). The scanning electron micrograph depicted that the microbe is highly branched and filamentous in nature. The enzyme production was positively regulated in the presence of copper sulfate. The impact of different fermentation parameters on tyrosinase production depicted that the maximized enzyme titer values were observed when this isolate was grown at 6.5 pH and at $30^{\circ}C$ temperature under agitated conditions (220 rpm). Among all the studied physiological parameters, agitation played a significant role on tyrosinase production. Upon optimization of the parameters, the yield of tyrosinase was improved more than 100% compared with the initial yield.

• Journal of Plant Biotechnology
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• 제35권1호
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• pp.41-45
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• 2008

Laccase (EC 1.10.3.2) is a small group of enzymes that catalyze the oxidation of a broad range of phenolic compounds including hazardous and recalcitrant pollutants in the environment. This study attempted to develop an efficient system for production of a recombinant laccase by chloroplast genetic transformation of tobacco. Chloroplast transformation vector was constructed and introduced into the tobacco chloroplast genome using particle bombardment. Chloroplast-transformed plants were subsequently regenerated. PCR and southern blot analyses confirmed stable integration of the laccase gene into the chloroplast genome. Northern blot analysis revealed that mRNA of the laccase gene was highly expressed in chloroplast-transformed plants.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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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.

• 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.

• Journal of Microbiology and Biotechnology
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• 제29권12호
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• pp.1861-1872
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• 2019

In the present work, we isolated and identified Aspergillus sydowii NYKA 510 as the most potent laccase producer. Its medium constituents were optimized to produce the highest possible amount of laccase, which was after 7 days at 31℃ and pH 5.2. Banana peel and peptone excelled in inducing laccase production at concentrations of 15.1 and 2.60 g/l, respectively. Addition of copper sulfate elevated enzyme yield to 145%. The fungus was employed in a microbial fuel cell (MFC). The best performance was obtained at 2000 Ω achieving 0.76 V, 380 mAm^-2, 160 mWm^-2, and 0.4 W. A project to design a self-sufficient lighting unit was implemented by employing a system of 2 sets of 4 MFCs each, connected in series, for electricity generation. A scanning electron microscopy image of A. sydowii NYKA 510 was utilized in algorithmic form generation equations for the design. The mixed patterning and patterned customized mass approach were developed by the authors and chosen for application in the design.