• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.96-99
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• 2006

In this study, we have attempted to determine the optimum concentration of inducers responsible for efficient laccase production by the white-rot fungus, Trametes sp. Variations in laccase activity were investigated with changing concentrations of 2,5-xylidine, syringaldazine, ABTS, and guaiacol. Enhancement of peak laccase activity was achieved via the combination of 2,5-xylidine with ABTS, syringaldazine, or guaiacol, resulting in increases of up to 359, 313, and 340%, respectively, as compared to control values. Among the tested inducers, the addition of 0.1mM of ABTS coupled with 1.0mM of 2,5-xylidine in the medium after 24 h of cultivation proved optimal with regard to laccase enzyme production.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.199-202
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• 2008

A white rot fungus Irpex lacteus produced lignin degrading enzymes, which showed degrading activity against various recalcitrant compounds. However, laccase, one of the lignin degrading enzymes, was too low to be assayed by spectrophotometry using o-tolidine as the chromogenic substrate in this fungus under various culture conditions. A laccase expression vector was constructed using a cDNA from Phlebia tremellosa with the constitutively expressed promoter of glyceraldehydes-3-phosphate dehydrogenase gene, and introduced into I. lacteus by the restriction enzyme mediated integration transformation through the protoplast-$CaCl_2$ procedure. Two transformants showed highly increased laccase activities at the early growth phase in the minimal liquid medium, and they not only degraded bisphenol A, a notorious endocrine disrupting chemical, but also removed the estrogenic activity effectively.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.52-60
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• 1989

This study was carried out to know the possibility of simultaneous utilization of laccase from white-rot fungus with cellulase on enzymatic hydrolysis of cellulosic substrate from autohydrolyzed oak wood. Laccases from 3 white-rot fungi, Pleurotus ostreatus. Ganoderma lucidum, and Phanerochaete chrysosporium, were isolated, purified and measured their activities. The highest activity was shown in Pleurotus ostreatus and the lowest in Phanerochaete chrysosporium. Laccase from Pleurotus ostreatus has optimum pH of 5.94, Km value of 3.209 mM and appeared to be stable at relatively wide pH range, 4.7-8.72. Temperature stability showed that 60% activity was preserved after 40 minutes at $50^{\circ}C$. Laccase from Ganoderma lucidum reached to the maximum activity during 15-20 day incubation. This enzyme has optimum pH of 6.45, Km value of 6.71 mM and pH range of 5.0-9.0 for stabilization. 95% activity was preserved at $30^{\circ}C$ and 58% activity at $50^{\circ}C$. Concerned to the enzymatic hydrolysis of cellulosic substrate with both enzymes, cellulase and laccase, simultaneously, mixed culture filtrates and mycellium extracts were shown higher hydrolysis rates than those of Trichoderma viride. There were no significant differences in the extent of hydrolysis among various mixed culture filtrates and mycellium extracts.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.79-82
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• 2017

An inky cap, Coprinus comatus synthesizes and secretes a laccase in the liquid yeast extract peptone dextrose medium. We have successfully purified the enzyme through the ion-exchange chromatography and the preparative gel electrophoresis. The estimated molecular weight was 67 kDa by the SDS-PAGE analysis. Optimum pH was pH 4.3 and optimum temperature was $25^{\circ}C$. The Km value was 0.45 mM and the Vmax was 0.0132 OD/min/unit for o-tolidine. Purified laccase showed 49.3% decolorizing activity against remazol brilliant blue R (RBBR) and 41.6% decolorizing activity against Poly R-478 after 12 h incubation.

• Journal of Mushroom
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• v.13 no.1
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• pp.63-67
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• 2015

White rot fungi produce lignin-degrading enzymes such as laccase, manganese peroxidase and lignin peroxidase. These extracellular oxidases efficiently degrade recalcitrant synthetic dyestuffs with diverse chemical structures. Here, we examined the activities of lignin-degrading enzymes in Trametes versicolor using triphenyl methane dyes, crystal violet (CV) and malachite green (MG). Both dyes were decolorized by T. versicolor in solid and liquid culture conditions. T. versicolor decolorized MG more quickly than CV in both conditions. Among three ligninolytic enzymes, laccase was most abundantly found in the decolorization processes of CV and MG. However, higher activity of laccase was needed to degrade CV than MG. The much less activity of MnP was also detected. But the increase of MnP activity was well corresponded to the decolorization efficiency of CV, suggesting the involvement of MnP in CV degrading process. However, its role in the degradation process of MG is supposed to be subsidiary to laccase.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.225-231
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• 2014

In this study about the optimum conditions for the production of laccase, a polyphenol oxidase involved in lignin degradation, from Marasmius scorodonius, a white-rot fungus garlic mushroom, were determined. Amongst the tested media used for the enzyme's production, YM medium (1% dextrose, 0.5% malt extract, 0.3% yeast extract) allowed for the highest activity of the enzyme. Then, to optimize the culture conditions for laccase activity, the influence of various carbon and nitrogen sources was investigated in YM medium. Among various carbon and nitrogen sources, 1% galactose and 0.4% yeast extract resulted in the highest production of the enzyme, respectively. Enzyme production attained its highest level after cultivation for 15 days at $25^{\circ}C$. Zymogram analysis of the culture supernatant showed two isoenzymatic bands with molecular masses of 60-70 kDa. The optimum pH and temperature for enzyme activity were 3.4 and $75^{\circ}C$, respectively.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.181-186
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• 2003

The production of laccase by Fomitella fraxinea was studied. The addition of minerals were necessary far laccase production by Fomitella fraxinea. Jar fermentor and Air-sparging fermentor performed high productivity In laccase activity by F. fraxinea. Laccase activity reached 3,540 in 8 days (Jar fermentor) and 3,100 in 6 days (Air-sparging fermentor) respectively.

• Journal of the Korean Wood Science and Technology
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• v.27 no.4
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• pp.72-79
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• 1999

The ability of several wood rotting fungi for decolorization of two anthracene derivatives, Carminic acid (CA) and Remazol brilliant blue R (RBBR), and hardwood KP bleaching liquor (BL) as well as laccase activities in these fungi were studied. The enzyme activity appeared exclusively in fungi destaining RBBR and CA, but in the case of BL, such relationship was not observed. The laccase enzyme was released into the decolorization media and its inducible (but not constitutive) forms shown destaining activity. The purified inducible forms of Kuehneromyces mutabilis and Pleurotus ostreatus laccase destained CA. Thus the possible differentiation between specificity of particular LAC forms was confirmed. In addition the nitrogen starvation induced both laccase and CA destaining activities, but the increase was higher for decolorization of CA than LAC activity. Probably LAC would be only partly responsible for decolorization of this dye. This results suggested that purified LACs decolorize CA, however its destaining activities were considerably lower than the activities on syringaldazine.

• Journal of Mushroom
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• v.15 no.4
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• pp.168-177
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• 2017

To evaluate effects of ligninolytic enzyme type on the mycelial response and ligninolytic enzyme production during interspecific interactions among wood-rotting fungi, 4 fungal strains, Trichophyton rubrum LKY-7, Trichophyton rubrum LSK-27, Pycnoporus cinnabarinus, and Trichoderma viride, were selected. Regarding ligninolytic enzyme production, LKY-7 secreted laccase and manganese peroxidase (MnP), P. cinnabarinus secreted only laccase, and LSK-27 secreted only MnP in glucose-peptone medium, while T. viride did not produce any ligninolytic enzymes. In the co-culture of LKY-7 with P. cinnabarinus, the formation of aerial mycelium was observed and the enhancement of laccase activity owing to interspecific interaction appeared to be very low. In the co-culture of LKY-7 and P. cinnabarinus with LSK-27, a hypha-free clear zone was observed, which resulted in deadlock, and increased laccase or MnP activity was detected at the interaction zone. The interaction responses of LKY-7, P. cinnabarinus, and LSK-27 with T. viride were characterized by the formation of mycelial barrages along the interface. As mycelial barrages were observed at the T. viride territory and no brownish pigment was observed in the mycelial barrages, it is suggested that laccase and MnP are released as part of an offensive response, not as a defensive response. The co-culture of P. cinnabarinus with T. viride lead to the highest enhancement in laccase activity, yielding more than 14-fold increase in laccase activity with respect to the mono-culture of P. cinnabarinus. MnP activities secreted by LKY-7 or LSK-27 was generally low in interspecific interactions.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.10
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• pp.1264-1270
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• 2011

This study is to optimize the conditions for the treatment of polyamide fabrics using laccase. The pH, temperature, treatment time, and concentration were varied; their effects were evaluated by measuring the number of primary amide groups by the uptake of an acid dye measured by K/S of dyed polyamide fibers. The hydrophilicity of the fabrics was evaluated in terms of moisture regain and wettability. The effects of the mediator, ABTS, on the laccase activity were also evaluated. The optimal treatment conditions were identified as a pH of 4.5, temperature of $30^{\circ}C$, treatment time of 6 hours, and concentration of 10% of the weight of the fabric (o.w.f.). ABTS facilitated the activity of laccase on the polyamide fabrics. Voids and cracks on the surfaces of the laccase-treated polyamide fabrics were responsible for improved wettability. The results proved that laccase treatment improved the hydrophilicity of polyamide fibers without decreasing their strength.