• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.463-470
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• 2020

The JS18 strain was isolated from an old tree forest and produced extracellular enzymes that decolorize synthetic melanin. Phylogenetic analysis, based on the internal transcribed spacer (ITS) sequence, indicate that JS18 belongs to the Trametes velutina species. JS18 demonstrated laccase activity but no manganese peroxidase or lignin peroxidase activity. Batch culture indicated that the melanin decolorization activity of JS18 strain originated from the laccase. Syringic acid and CuSO4 induced maximum laccase production, yielding 98 U/ml laccase activity after cultivation for 7 days at 25℃. T. velutina secretes an extracellular laccase in GYP medium, and this enzyme was purified using (NH4)2SO4 precipitation, Hi-trap Q Sepharose columns and gel filtration. The molecular weight of the purified enzyme was estimated to be 67 kDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis. This enzyme produced 80% of its melanin decolorization activity within the first 24 h of evaluation in the presence of 1-hydroxybenzotriazole (HBT), while only about 4% of the melanin was decolorized in the absence of the mediator. The greatest decolorization was observed at 1.5 mM/l HBT, which decolorized 81% of the melanin within the first 24 h. The optimum pH and temperature for this decolorization were found to be 5.0 and 37℃, respectively. Our results suggest the possibility of applying HBT induced T. velutina JS18 laccase-catalyzed melanin decolorization.

• The Korean Journal of Mycology
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• v.22 no.3
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• pp.254-259
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• 1994

The ever increasing demand for energy and the shortage of resources all over the world have generated interest in recycling renewable sources such as lignocelluloses which otherwise would go to waste and cause environmental pollution. Lignin is the incrustation material for cellulose and hemicellulose, therefore, cellulose and hemicellulose are not easily degraded. Recycling lignocellulosic wastes as agricultural material are benefit to everybody and everything. In order to improve ligninase and laccase production of Phanerochaete chrysosporium, BKM-F-1767 and Ceriporiopsis subvermispora, FP 90031-SP, were compared. The ligninase activity of P. chrysosporium was maximum on day 4.5 of shaking culture at 150 rpm 2.5 cm in a back and forth cycle. The laccase activity of C. subvermispora was maximum on day 5.5 for 2% malt extract+0.1% yeast extract+0.1% Tween 20+6 mM Benzyl alcohol culture medium at stationary state.

• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.61-66
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• 2007

The study was performed to purify and characterize laccase in culture of Trametes versicolor. The fungus was grown in liquid culture media of PDB and added 2,5-xylidine (0.2 mM) after 5 days to enhance the production of laccase. The fungal culture was incubated at $25^{\circ}C$ on a rotary shaker (120 rpm) for 7days, and the culture broth was clarified through Glass filter (GF/C). The aqueous solution was concentrated by ultramicrofiltration (Viva flow 50, GE Healthcare Bioscience, USA) and loaded onto a Hitrap Q FF column. Laccase activity could be detected at one peak, and this enzyme has a molecular mass of approximately 53kDa as determined by SDS-PAGE The optimum pH and temperature for syringaldazine were 5.0 and $60^{\circ}C$, respectively. The specific activity of crude, concentrated and purified laccase were 32, 409, and 1,243 U/mg, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.5
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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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• 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).

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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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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• v.35 no.1
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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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• 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.

• 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.29 no.12
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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.