• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.133-139
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• 2010

Photoelectrocatalytic decolorization of methlene blue (MB) in the presence of two types of carbon nanotube/titania and yttrium-treated carbon nanotube/titania electrodes in aqueous solutions were studied under visible light. The prepared composite electrodes were characterized by X-ray diffraction, transmission and scanning electron microscopy, energy dispersive X-ray analysis, and photoelectrocatalytic activity. The photoelectrocatalytic performances of the supported catalysts were evaluated for the decolorization of MB solution under visible light irradiation. The results showed that yttrium incorporation enhanced the decolorization rate of MB. It was found that the photoelectrocatalytic degradation of a MB solution could be attributed to the combined effects caused by the photo-degradation of titania, the electron assistance of carbon nanotube network, the enhancement of yttrium and a function of the applied potential. The repeatability of photocatalytic activity was also tested. The presence of yttrium enhanced the hydrophillicity of yttrium-carbon nanotubes/titania electrode because more OH groups can be adsorbed on the surface.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1120-1127
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• 2017

Marasmius scorodonius secretes an extracellular laccase in potato dextrose broth, and this enzyme was purified up to 206-fold using $(NH_4)_2SO_4$ precipitation and a Hi-trap Q Sepharose column. The molecular mass of the purified laccase was estimated to be ~67 kDa by SDS-PAGE. The UV/vis spectrum of the enzyme was nontypical for laccases, and metal content analysis revealed that the enzyme contains 1 mole of Fe and Zn and 2 moles of Cu per mole of protein. The optimal pH for the enzymatic activity was 3.4, 4.0, and 4.6 with 2,2'-azino-bis(3-ethylbenzothazoline-6-sulfonate) (ABTS), guaiacol, and 2,6-dimethoxy phenol as the substrate, respectively. The optimal temperature of the enzyme was $75^{\circ}C$ with ABTS as the substrate. The enzyme was stable in the presence of some metal ions such as $Ca^{2+}$, $Cu^{2+}$, $Ni^{2+}$, $Mg^{2+}$, $Mn^{2+}$, $Ba^{2+}$, $Co^{2+}$, and $Zn^{2+}$ at a low concentration (1 mM), whereas $Fe^{2+}$ completely inhibited the enzymatic activity. The enzymatic reaction was strongly inhibited by metal chelators and thiol compounds except for EDTA. This enzyme directly decolorized Congo red, Malachite green, Crystal violet, and Methylene green dyes at various decolorization rates of 63-90%. In the presence of 1-hydroxybenzotriazole as a redox mediator, the decolorization of Reactive orange 16 and Remazol brilliant blue R was also achieved.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1433-1441
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• 2015

Pollution resulting from the discharge of textile dyes into water systems has become a major global concern. Because peroxidases are known for their ability to decolorize and detoxify textile dyes, the peroxidase activity of Vitreoscilla hemoglobin (VHb) has recently been studied. It is found that VHb and variants of this enzyme show great promise for enzymatic decolorization of dyes and may play a role in achieving their successful removal from industrial wastewater. The level of VHb peroxidase activity correlates with two amino acid residues present within the conserved distal pocket, at positions 53 and 54. In this work, sitedirected mutagenesis of these residues was performed and resulted in improved VHb peroxidase activity. The double mutant, Q53H/P54C, shows the highest dye decolorization and removal efficiency, with 70% removal efficiency within 5 min. UV spectral studies of Q53H/P54C reveals a more compact structure and an altered porphyrin environment (λ_Soret = 413 nm) relative to that of wild-type VHb (λ_Soret = 406), and differential scanning calorimetry data indicate that the VHb variant protein structure is more stable. In addition, circular dichroism spectroscopic studies indicate that this variant's increased protein structural stability is due to an increase in helical structure, as deduced from the melting temperature, which is higher than 90℃. Therefore, the VHb variant Q53H/P54C shows promise as an excellent peroxidase, with excellent dye decolorization activity and a more stable structure than wild-type VHb under high-temperature conditions.

• Journal of the Korean Wood Science and Technology
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• v.34 no.4
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• pp.46-53
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• 2006

This study was to screen white-rot fungi possesing strong lignin degrading enzymes, glucose-1 oxidase (GOD), laccase (LAC) and Mn-peroxidase (MnP), based on their decolorization activity of Remazol Brilliant Blue R (RBBR). In the midst of 20 tested fungi, 9 isolates were shown 4 kinds of activities such as RBBR decolorization, GOD, LAC and MnP. Relatively high active strains were identified as Phlebia radiata, Trametes versicolor, Abortiporus biennis, Gleophyllum odoratum and Cerrena unicolor. In particular, T. versicolor, G. odoratum, and C. unicolor, which have high activities of LAC, were used to confirm the optimal temperature and pH and to evaluate the effect of inducer, 2,5-xylidine on their LAC activity. The optimum temperatures for mycelial growth were $28^{\circ}C$ for T. versicolor and G. odoratum, and $25^{\circ}C$ for C. unicolor. The optimum pH for mycelial growth was 5.5. Three strains showed the increase of LAC enzyme activity by the addition of 2,5-xylidine. T. versicolor had the highest LAC activity of $22,700nkat/{\ell}$, corresponding to 11.3 times, G. odoratum $15,400nkat/{\ell}$, 9 times and C. unicolor $17,330nkat/{\ell}$, 5.5 times higher than those of the control.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.8-15
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• 1998

The present research was undertaken to investigate the activity of ligninolytic enzymes and the decolorization capability of some dyes with Irpex zonatus BN2, isolated from nature and identified. For the assay of enzyme activities, the isolate did not produce lignin peroxidase (LiP) and veratryl alcohol oxidase (VAO), but laccase and manganese dependent peroxidase (MnP). While the activity for MnP was low $(61.6\;nmol/mg{\cdot}protein)$, its laccase activity was very high $(1185.9\;nmol/mg{\cdot}protein)$. Moreover, laccase had appeared earlier than MnP. When the isolate was incubated with each dye for 10 days, the decolorization rates of azo dyes, such as orange II, orange G, tropaeolin O and congo red were 98.0%, 97.4%, 99.0% and 95.3%, respectively. In case of heterocyclic dyes, eosin Y, toludine blue, methyl blue and azur B were 97.4 %, 98.7%, 99.9% and 94.0% respectively. Finally the results of triphenylmethane dye such as basic fuchsin, malachite green and crystal violet were 98.5%, 95.7% and 99.4%, respectively. The results suggest that laccase of Irpex zonatus BN2 should be played an important role in the decolorization of the dyes.

• KSBB Journal
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• v.18 no.5
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• pp.398-403
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• 2003

Due to the low biodegradability of dyes, conventional biological wastewater treatment systems are inefficient in treating dye wastewater. Various white-rot fungi were investigated for the decolorization of six industrial dyes (reactive blue 5, reactive blue 16, reactive black 5, acid black 52, reactive orange 16, and acid violet 43). Among ten fungi, T. versicolor KCTC 16781 was selected as a testing strain because this had the best performance of decolorization for six dyes from the results of the solid culture experiments. In liquid culture medium, T. versicolor KCTC 16781 decolorized over 96% of six dyes for 48 hrs. Laccase started to produce in the early stage of the culture, and showed the highest peak value of 2.3 U/mL in 24 hrs. Enzyme activity remained constant until the end of culture. Fungal decolorization is a promising alternative to replace or supplement present treatment process.

• 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.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.252-256
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• 1997

The white rot fungus Coriolus hiysutus decolorized several recalcitrant dyes. Four different types of dyes, including azo, triphenyl methane, heterocyclic, and polymeric dye, were treated by the mycelial preparation. Triphenyl methane dye, bromophenol blue lost over 95% of its color. Congo red and Poly R-478 were decolorized less than bromophenol blue, 57 and 55%, respectively. However, heterocyclic dye, methylene blue was not decolorized significantly and only red shift was observed. Extracellular laccase and peroxidase activities were appeared maximally in high level of dye decolorization media. In electrophoretic experiments, common active bands of laccase and peroxidase were found in all dye decolorized medium. These results indicated that the culture conditions which yield high levels of laccase and peroxidase activity lead to high levels of dye decolorization, and these two enzymes might be play an important roles in dye decolorization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.655-661
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• 2018

This study was performed to evaluate the antioxidant activity capacity of extracted seed oils by pressure method using domestic plant resources as a cosmetics material. Four type of oil were extracted from pumpkin seed, camellia seed, red pepper seed, peanut. The extracted seed oils were analyzed for fatty acid composition by GCMS, The antioxidant activity evaluated by DPPH radical scavenging activity, ABTS radical cation decolorization activity. Pumpkin seed oil(PSO), camellia seed oil(CSO), peanut oil(PO) showed higher ratio of unsaturated fatty acid than saturated fatty acid. After heat treatment, the content of unsaturated fatty acids was higher than that of saturated fatty acids except for red pepper seed oil(RSO). In the result of DPPH, ABTS antioxidant activity, RSO were the highest 87.84%, 76.72% at the $200{\mu}{\ell}/m{\ell}$, PSO, PO and CSO were the highest antioxidant activities at the $1000{\mu}{\ell}/m{\ell}$. Compared with the positive control olive oil, DPPH radical scavenging activity of RSO, PSO and PO showed higher than the control. ABTS radical cation decolorization activity of RSO and PSO is stronger than the control. After heat treatment, the antioxidant activity capacity showed a slight difference, four type of oils is expected as having potential to be useful as a cosmetic material.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.226-231
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• 2006

Several white-rot fungi are able to produce extracellular lignin-degrading enzymes such as manganese peroxidase (MnP), lignin peroxidase (LiP), and laccase. In order to enhance the production of laccase and MnP using Trametes versicolor KCTC 16781 in suspension culture, the effects of major medium ingredients, such as carbon and nitrogen sources, on the production of the enzymes were investigated. The decolorization mechanism in terms of biodegradation and biosorption was also investigated. Among the carbon sources used, glucose showed the highest potential for the production of laccase and MnP. Ammonium tartrate was a good nitrogen source for the enzyme production. No significant difference in the laccase production was observed, when glucose concentration was varied between 5 g/l and 30 g/l. As the concentration of nitrogen source increased, a lower MnP activity was observed. The optimal C/N ratio was 25 for the production of laccase and MnP. When the concentrations of glucose and ammonium tartrate were simultaneously increased, the laccase and MnP activities increased dramatically. The maximum laccase and MnP activities were 33.7 U/ml at 72 h and 475 U/ml at 96 h, respectively, in the optimal condition. In this condition, over 90% decolorization efficiency was observed.