• The Korean Journal of Mycology
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• v.46 no.3
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• pp.255-269
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• 2018

Armillaria is a white-rot fungus that decomposes organics; it is also a root pathogen that kills trees. Recently, since the forest tending practice, the incidence of Armillaria infections on tree stumps has been increasing. Herein, we have examined the morphological features of Armillaria solidipes and A. gallica collected from 10 areas in Korea, and investigated the activities of the decomposing enzymes cellulase and laccase of these two Armillaria species. A. solidipes was found in eight host tree species including Pinus densiflora, Quercus serrata, and Castanea crenata at the altitude of 107~1,396 m, while A. gallica was found in three host species including P. densiflora and Fraxinus rhynchophylla at the altitude of 119~556 m. The fruiting bodies of A. solidipes are close with lamellae, and have brown to black hairs on the stipe, while those of A. gallica are distant with lamellae and clavate-shaped, and have yellow hairs on the base. The activites of cellulase of the two species were not different, but the activity of A. solidipes laccase was higher ($12.94{\pm}0.4U/mL$) than that of A. gallica laccase ($9.14{\pm}0.3U/mL$).

• Journal of the Korean Wood Science and Technology
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• v.26 no.3
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• pp.63-72
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• 1998

In order to evaluate the biodegradability and mechanism of 4,5,6-trichloroguaiacol (TCG) produced from bleaching process in pulp mill by Phanerochaete chrysosporium, Trametes versicolor, and Inonotus cuticularis, changes in TCG and its metabolites during biodegradation were analyzed by HPLC, and GC/MS spectrometry. By three fungi, the maximum biodegradability against TCG were very quickly reached, compared with other chlorinated aromatic compounds such as PCP. Within 24 hrs, T versicolor indicated up to 95% of TCG removal rate, and P. chrysosporium and I. cuticularis also showed more than 80%, and 90%, respectively. Particularly, in case of T. versicolor, the removal rate of TCG after 1 hr. incubation was reached to approximately 90%, implying very rapid metabolization of TCG. However, by analyzing the filtrates extracted from TCG containing culture by GC/MS, the major metabolites at initial stage of biodegradation were dimers, indicating that the added TCG monomers were quickly polymerized. The others were trichloroveratrole, dichloroguaiacol, and trichlorobenzoic acid, suggesting that TCG may be biodegraded by several sequential reactions such as polymerization, oxidation, methylation, dechlorination, and hydroxylation. In other experiments, the extracellular fluid which did not contain any fungal mycelia was used to evaluate the effect of mycelia on TCG biodegradation. The extracellular fluid of T. versicolor also biodegraded TCG up to 90% within 24hrs, but those of P. chrysosporium and I. cuticularis did not show any good biodegradability. T versicolor showed the highest value of laccase, and other two fungi indicated a little activity of lignin peroxidase (LiP) and manganese peroxidase (MnP). In addition, the laccase activity of T. versicolor was very linearly proportional to the removal rate of TCG during incubation, in other words, showing the induction effect against TCG. Consequently, the biodegradation of TCG was very dependent upon the activity of laccase.

• Journal of the Korean Wood Science and Technology
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• v.40 no.6
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• pp.424-430
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• 2012

In this study, laccase activity, rate of weight loss and degree of lignin degradation of pine wood chips were determined during the liquid and solid state incubation with Polyporus brumalis. The results showed that laccase enzyme activity at untreated wood chip was gradually decreased after 20 days, but enzyme activity with wood chip treatment showed 10 times higher than untreated ones at 60 incubation days. Rate of weight losses of pine chip and rate of lignin loss were 23.4% and 6.3% by P. brumalis during 80 incubation days. Gene expression of pblac1 from P. brumalis was 3 times increased under pine chip treatment at 40 incubation days. Consequently, laccase activity of white rot fungi, P. brumalis, was increased at incubation with wood chip and pblac1 gene was important factor of lignin degradation. Therefore, to regulate lignin degrading enzyme gene expression by using the tools of biotechnology will be able to develop superior strains and it will be useful for pretreatment of lignocellulosic biomass at bioethanol production.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.100-103
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• 2004

The culture condition and medium composition for the enhanced mycelial growth of Inonotus mikadoi IMSNU 32058 were investigated. The optimal temperature and pH for the mycelial growth were $27^{\circ}C$ and pH 4.5, respectively. Among the complex media tested, the malt extract medium and Phellinus igniarius medium were very good for mycelial growth of I. mikadoi. When Czapek-Dox medium was used as a minimal medium for cultivation of mycelia, xylose, raffinose and carboxymethyl cellulose were very excellent as a carbon and energy source. With respect to carbohydrate, sucrose and glucose were very good carbon sources. In general, organic complex nitrogen sources were better than other inorganic ones. As the organic complex nitrogen sources tested, yeast extract, soytone, proteose peptone and bacto peptone were the best as a source of organic nitrogen. When ammonium sulfate as an inorganic source of nitrogen was used, the enhanced mycelial growth was shown. p-Aminobenzoic acid was proved to be most appropriate source of vitamin. After the mycelia of I. mikadoi was cultivated at $27^{\circ}C$ for 5 days in MEM broth (pH 4.5), the activities of both exomycelial and endo-mycelial enzymes were determined. Among endomycelial enzymes assayed, the specific activity of laccase was much higher than those of other enzymes. When the fungus was grown in MEM broth, exomycelial specific enzyme activity of laccase was comparatively high. However, little or no enzyme activities of protease, chitinase and lipase were found.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.19-32
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• 2013

In this study, outstanding white rot fungi for biodegradation of organosolv lignin were selected on the basis of their ligninolytic enzyme system. Fifteen white rot fungi were evaluated for their ability to decolorize Remazol Brilliant Blue R (RBBR) in SSC and MEB medium, respectively. Six white rot fungi (Ceriporiopsis subvermispora, Ceriporia lacerate, Fomitopsis insularis, Phanerochaete chrysosporium, Polyporus brumalis, and Stereum hirsutum) decolorized RBBR rapidly in SSC medium within 3 days. The protein contents as well as the activities of manganese peroxidase (MnP) and laccase for 6 selected fungi were determined on the SSC medium with and without organosolv lignin. Interestingly, extracellular protein concentrations were determined to relative higher for S. hirsutum and P. chrysosporium in the presence of organosolv lignin than others. On the other hands, each fungus showed a different ligninolytic enzyme pattern. Among them, F. insularis resulted the highest ligninolytic enzyme activities on incubation day 6, indicating of 1,545 U/mg of MnP activity and 1,259 U/mg of laccase activity. In conclusion, $STH^*$ and FOI were considered as outstanding fungi for biodegradation of organosolv lignin, because $STH^*$ showed high extracellular protein contents and ligninolytic enzyme activities over all, and ligninolytic enzyme activities of FOI were the highest among white rot fungi used in this study.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.469-480
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• 2011

In this study, to determine the ligninase activity related to the PCBs degradation of Ceriporia sp. ZLY-2010, the protein contents and manganese peroxidase (MnP) and laccase activities during cultivation on shallow stationary culture (SSC) medium were observed. 4 PCB congeners were selected depending on the number of chlorine substituted on biphenyl. Furthermore, to examine the effects of cytochrome P450 monooxygenase, the inhibition of cytochrome P450 monooxygenase was evaluated by measuring the biodegradation rate when inhibitor such as 1-aminobenzotriazole was added. The extracellular protein contents were affected by PCB congeners in culture media. The total protein in the culture medium showed the biggest differences between the samples containing 2,2',4,4',5,5'-hexachlorobiphenyl and the control. On the other hand, MnP and laccase activity showed dominant increases within samples containing 4,4'-dichlorobiphenyl and 2,3',4',5-tetrachlorobiphenyl. Cytochrome P450 monooxygenase was inhibited by adding inhibitor, 1-aminobenzotriazole in low concentration. Only 2.73% of 2,3',4',5-tetrachlorobiphenyl was degraed on day 1, and biodegradation of 2,2',4,4',5,5'-hexachlorobiphenyl was inhibited as well, showing about 20% of biodegradation rate.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.246-254
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• 2018

Enzyme fermentation is a type of food processing technique generally used to improve the biological activities of food and herbal medicines. In this study, a Syzygii Flos (clove) extract was fermented using laccase derived from Trametes versicolor (LTV). The fermented clove extract showed greater neuroprotective effects against glutamate toxicity on HT22 than the non-fermented extract did. HPLC analysis revealed that the eugenol (1) and dehydrodieugenol (2) contents had decreased and increased, respectively, after fermentation. The content of 2 peaked at 1 h after fermentation to $103.50{\pm}8.20mg/g_{ex}$ (not detected at zero time), while that of 1 decreased to $79.54{\pm}4.77mg/g_{ex}$ ($185.41{\pm}10.16mg/g_{ex}$ at zero time). Compound 2 demonstrated promising HT22 neuroprotective properties with inhibition of $Ca^{2+}$ influx, the overproduction of intracellular reactive oxygen species, and lipid peroxidation. In addition, LTV showed the best fermentation efficacy compared with laccases derived from Pleurotus ostreatus and Rhus vernicifera.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.833-837
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• 2004

DeniLite$^{TM}$ laccase immobilized platinum electrode was used for amperometric detection of hydroquinone (HQ) and homogentisic acid (HGA) by means of substrate recycling. In case of HQ, the obtained sensitivity is 280 nA/ ${\mu}$M with linear range of 0.2-35 ${\mu}$M ($r^2$ = 0.998) and detection limit (S/N = 3) of 50 nM. This high sensitivity can be attributed to chemical amplification due to the cycling of the substrate caused by enzymatic oxidation and following electrochemical regeneration. In case of HGA, the obtained sensitivity is 53 nA/ ${\mu}$M with linear range of 1-50 $[\mu}M\;(r^2$ = 0.999) and detection limit of 0.3 ${\mu}$M. The response times ($t_{90%}$) are about 2 seconds for the two substrates and the long-term stability is 60 days for HQ and around 40-50 days for HGA with retaining 80% of initial activities. The very fast response and the durable long-term stability are the principal advantages of this sensor. pH studies show that optimal pH of the sensor for HQ is 6.0 and that for HGA is 4.5-5.0. This shift of optimal pH towards acidic range for HGA can be attributed to the balance between enzyme activity and accessibility of the substrate to the active site of the enzyme.

• Mycobiology
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• v.29 no.3
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• pp.173-175
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• 2001

The fruit body of Ramaria botrytis DGUM 29001 was used to determine enzyme activities of fruit body. The specific activity of laccase was the highest(6.5 unit/mg$\cdot$protein) and that of $\alpha$-amylase and xylanase was relatively high. However, little or no enzyme activity of $\beta$-glucosidase, CMCase, exo-$\beta$-1,4-glucanase, chitinase, lipase and protease was found.

• Mycobiology
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• v.47 no.4
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• pp.512-520
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• 2019

Statistical experimental methods were used to optimize the medium for mass production of a novel laccase3 (Lac3) by recombinant Saccharomyces cerevisiae TYEGLAC3-1. The basic medium was composed of glucose, casamino acids, yeast nitrogen base without amino acids (YNB w/o AA), tryptophan, and adenine. A one-factor-at-a-time approach followed by the fractional factorial design identified galactose, glutamic acid, and ammonium sulfate, as significant carbon, nitrogen, and mineral sources, respectively. The steepest ascent method and response surface methodology (RSM) determined that the optimal medium was (g/L): galactose, 19.16; glutamic acid, 5.0; and YNB w/o AA, 10.46. In this medium, the Lac3 activity (277.04 mU/mL) was 13.5 times higher than that of the basic medium (20.50 mU/mL). The effect of temperature, pH, agitation (rpm), and aeration (vvm) was further examined in a batch fermenter. The best Lac3 activity was 1176.04 mU/mL at 25 ℃, pH 3.5, 100 rpm, and 1 vvm in batch culture.