• Korean Journal of Microbiology
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• v.27 no.4
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• pp.348-356
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• 1989

An extracellular peroxidase found in culture broth of Pleurotus ostreatus was induced by syringic acid. This enzyme was fractionated by DEAE Sephadex A-50 ion exchange chromatography and gel filtration chromatogrphy on Sephadex G-150. The enzyme is a glycoprotein containing 35.7% carbohydrate. The results of SDS-linear polyacrylamide gradient gel electrophoresis and gel filtration indicate that the enzyme is a dimer consisted of identical subunits (Mr=72,400). The absorption spectrum of the enzyme indicates the presence of one mole of iron protoporphyrin IX per one mole of subunit. Isoelectric point of the enzyme is 4.26 and $K_m$ values for $H_2O_2$ is $7.2{\mu}M$. The enzyme showed its optimal activity at pH 3.5-4.0 and at $40^{\circ}C$. The Km values of this enzyme for ferulic acid and sinapic acid are 2.4 and 12.3 times higher than those of horseradish peroxidase, respectively.

• BMB Reports
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• v.32 no.2
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• pp.168-172
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• 1999

We previously reported that a novel thiol peroxidase (p20) from Escherichia coli is a distinct periplasmic peroxidase that detoxifies hydroperoxides together with glutathione or thioredoxin. Until now, there was no experimental evidence for the presence of thioredoxin (Trx) in the periplasmic space. In an attempt to confirm the physiological function of p20 as a thiol peroxidase supported by Trx in the periplasmic space, we have purified a Trx activity from the periplasmic space of Escherichia coli and identified the Trx as the same protein as the cytoplasmic Trx. The presence of Trx in the periplasmic space of Escherichia coli suggests that p20 is a unique extracellular Trx-linked thiol peroxidase.

• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.420-424
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• 1996

Effects of exogenous veratryl alcohol addition on the growth of basidiomycete Phanerochaete chrysosporium ME-446 and the induction of lignin peroxidase activity were investigated in this study. The organism was grown in ligninolytic (low-nitrogen) culture conditions in which extracellular enzymes are produced. Analyses showed that a statistically significant decrease of cell growth was associated with the veratryl alcohol addition. The effect of veratryl alcohol addition on LiP activity was nearly instantaneous and this effect diminished with culture aging. The extent of this effect was different depending on the time of addition, which led to a speculation that there might be some other effector species which played a role in regulation of lignin peroxidase activity.

• KSBB Journal
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• v.15 no.5
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• pp.525-528
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• 2000

Time course monitoring of FCW/DCW ratio, production of intra and extracellular protein, and peroxidase activity were performed during suspension culture of Taxus chinensis cells. The observed FCW/DCW ratio was 12 at day 14, which was the lowest value during cultivation, and the specific protein production, based on dry cell weight, was also the lowest at day 14, which showed 4.3 mg/g DCW. The pattern of POD activity was similar to that of protein production. The results in this report were obtained using actively growing cells in flasks, therefore it is possible to use those results to control the process and indicate the stresses imposed on cells during large-scale cultivation.

• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.972-978
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• 2002

Streptomyces sp. AD001 is a Gram-positive soil actinomycetes secreting an uncharacterized 2,4-dichlorophenol (DCP) oxidizing enzyme, whose activity is similar to the previously known Actinomycetes lignin-peroxidase (ALiP). This extracellular peroxidase was purified from Streptomyces sp. AD001 as a single protein band on an SDS-PACE by ammonium sulfate fractionation, Q-sepharose, concanavalin A, and Bio-Gel HTP column chromatographies. The molecular mass of the purified peroxidase was determined by SDS-PAGE to be 45.2 kDa, and 49.7 kDa with MALDI-TOF-MS, respectively. The highest level of peroxidase activity was observed at pH 7.5 and $30^{\circ}C$. The amino terminal sequence of the purified peroxidase (G-E-P-E-E-G-N-V-D-G-T-L) showed no significant homologies to my known proteins, suggesting that Streptomyces sp. AD001 may secrete a novel kind of bacterial peroxidase Initial rate kinetic data of the 2,4-DCP oxidation were best modeled with a random-binding bireactant system.

• Journal of the Korean Wood Science and Technology
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• v.32 no.6
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• pp.14-22
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• 2004

The effect of cadmium ions on ligninolytic and decolourizing activities in cultures of two white-rot fungi, Cerrena unicolor and Trametes versicolor, were examined. Cadmium was added to the shallow stationary cultures growing on a liquid mineral medium. Both examined strains sorbed Cd ions in the first 24 hr of incubation. An appreciable stimulation of the activity of extracellular laccase (LAC) and inhibition of the extracellular manganese-dependent peroxidase (MnP) were simultaneously observed when 25 mgL^-1 and 50 mgL^-1 of cadmium ions were added to the cultures. On the other hand, the addition of cadmium ions also resulted in stimulating the decolorization activity of C. unicolor to decolorize Remazol Brilliant Blue R (RBBR) in the cultures, but decreasing it in the culture of T. versicolor, which is compared to the inhibition of MnP activity in this fungus. Our data indicate that the presence of Cd(II) ions can affect the ligninolytic activity of white-rot fungi. It was found that C. unicolor is a strain resistant to the presence of Cd ions in the liquid culture media, and has a potential to use this strain for bioremediation of sites contaminated with both heavy metals and aromatic pollutants.

• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.53-61
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• 1999

Effects of culture conditions and Mn(II) addition were investigated for production of extracellular manganese peroxidase by lignin-degrading fungus LSK-27, Nitrogen source was shown to more influence the production of extracellular manganese peroxidase by LSK-27 than carbon source. When peptone or yeast extract as nitrogen source was added, high MnP activity was obtained. Especially, nitrogen-sufficient culture condition was effective in MnP activity, showing significantly increase up to 1.0% peptone concentration, but carbon-sufficient was not. Mn(II) was shown to strongly induce the MnP production in culture fluids of LSK-27. Increase of MnP actiyity was obeserved up to addition of 100ppm Mn(II), and over this Mn(II) concentration appeared to be inhibitory. The highest level of MnP activity was attained when Mn(II) was added after 2 day incubation.

• 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 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.

• KSBB Journal
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• v.21 no.2
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• pp.85-89
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• 2006

Typical property of the white-rot fungi is their ability to degrade lignin and other aromatic compounds with non-specific extracellular enzyme. In this work, the modification of the strain(Funalia trogii ATCC 200800) and the culture condition was performed to enhance enzyme productivity. Single cell was separated by the protoplasts formation and several putative laccase and manganese peroxidase inducers were tested. By adopting the modified strain, enzyme productivity increased comparing with that of the original strain. Extracellular enzyme formation was highly stimulated by the addition of copper and various aromatic compounds in the glucose-based culture medium.