• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.93.1-93
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• 2002

• 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 Agricultural Science
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• v.28 no.2
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• pp.125-131
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• 2001

Trametes versicolor(CV5) selected as a white-rot fungus with strong lignin degrading activity, in the previous paper, was investigated on a properties of degradation of wood lignin. Lignins of hardwoods, especially oak(Querous acutissima carruth) an paulownia (Paulownia coreana Uyeki) were considerably delignified by the CV5, however, softwoods used in this experiment were not delignified. Bavendamm's reaction was positive with several phenols on agar plates for the confirmation of a phenoloxidase secreted Through the morphologies of decayed wood chip observed with the aid of scanning electron microscopy, it was found that the hypha of CV5 penetrated the ray cells and vessels caused separation of the wood cellulose.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.29-40
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• 2000

Highly purified Cerrena unicolor laccase (benzenediol:oxygen oxidoreductase, EC 1.10.3.2) caused the demethoxylation of milled wood lignin and several lignin related substances. The constitutive form of the enzyme produced extracellularly by C. unicolor fermenter culture was isolated and purified by ion-exchange chromatography on the DEAE-Toyopearl column and by affinity chromatography on a ConA-Sepharose and Syringyl-AH-Sepharose 4B columns. The enzyme was further immobilized on functionalized porous glass (CPG) and keratin coated CPG. The demethylating activity was monitored both by estimation of released methanol and by detection of the level of methoxyl groups (also in some water miscible solvents) after incubation of lignin materials with laccase preparations (free and immobilized). The effects of the incubation time and temperature on the demethoxylating activity of immobilized laccase preparations were also studied.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1361-1370
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• 2015

A blue laccase was purified from a white rot fungus of Trametes trogii, which was a monomeric protein of 64 kDa as determined by SDS-PAGE. The enzyme acted optimally at a pH of 2.2 to 4.5 and a temperature of 70℃ and showed high thermal stability, with a half-life of 1.6 h at 60℃. A broad range of substrates, including the non-phenolic azo dye methyl red, was oxidized by the laccase, and the laccase exhibited high affinity towards ABTS and syringaldazine. Moreover, the laccase was fairly metal-tolerant. A high-molecular-weight kraft lignin was effectively polymerized by the laccase, with a maximum of 6.4-fold increase in weight-average molecular weight, as demonstrated by gel permeation chromatography. Notable structural changes in the polymerized lignin were detected by Fourier transform infrared spectroscopy and ¹H NMR spectroscopy. This revealed an increase in condensed structures as well as carbonyl and aliphatic hydroxyl groups. Simultaneously, phenolic hydroxyl and methoxy groups decreased. These results suggested the potential use of the laccase in lignin modification.

• The Korean Journal of Mycology
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• v.44 no.1
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• pp.61-63
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• 2016

Sclerotium rot disease on cowpea (Vigna sinensis King) was observed in the exhibition field of Gyeongsangnam-do Agricultural Research and Extension Services in September 2015. Lesions were covered by white mycelial mats, and numerous sclerotia were formed on the stem near the soil line. The sclerotia were globoid in shape, 1~3 mm in size and white to brown in color. The optimum temperature for mycelial growth and sclerotia formation on potato dextrose agar (PDA) was $30^{\circ}C$, with the hyphal width of $4{\sim}8{\mu}m$. For molecular identification, the complete internal transcribed spacer (ITS) rDNA region of the causal fungus was sequenced and analyzed. Based on the mycological characteristics, ITS rDNA sequence analysis, and pathogenicity test, this fungus was identified as Sclerotium rolfsii. This is the first report of sclerotium rot on cowpea caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.14 no.2
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• pp.131-133
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• 2008

From 2006 to 2007, the stem rot of Elsholtzia splendens Nakai caused by Sclerotium rolfsii occurred sporadically in an herbs exhibition at Gyeongsangnam-do Agricultural Research and Extension Services, Korea. The typical symptom is water-soaking, dark brown on the stem and rotting, wilting and blighting. The infected plants were mostly died. White mycelial mats were spread over lesions, and then sclerotia were formed on stems and near soil line. The sclerotia were globoid in shape, $1{\sim}3$ mm in size and white to brown in color. The optimum temperature and sclerotia on PDA was $30^{\circ}C$ and the hyphal width was $4{\sim}9{\mu}$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the stem rot of E. splendens caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.15 no.1
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• pp.51-53
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• 2009

The fruit rot of watermelon (Citrullus lanatus) occurred sporadically in the farmers field at Chojeondong, Jinju city, Korea, in 2007. The typical symptom was water-soaked, brown on the fruit, and than infected fruits were mostly rotted. White mycelial mats were spread over lesions, and then sclerotia were formed on fruit and near soil line. The sclerotia were globoid in shape, $1{\sim}3\;mm$ in size and white to brown in color. The optimum temperature for mycelial growth and sclerotia formation on PDA was $30^{\circ}C$ and the hyphal width was $4{\sim}8{\mu}m$. The typical clamp connections were observed in the hyphae of the fungus. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii. This is the first report on the fruit rot of watermelon by S. rolfsii in Korea.

• The Korean Journal of Mycology
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• v.35 no.1
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• pp.54-57
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• 2007

Rhizopus soft rot caused by Rhizopus stolonifer occurred on banana (Musa sapientum) in the box at Jinju City Wholesale Market of Agricultural Products at Gyeongnam province in Korea. The infected fruits were rapidly water-soaked, softened, blackened and eventually rotted. They were infected from wounds at harvest time. The colony of the isolate from the infected fruit was white to light brown and formed many sporangiospores. The optimum growth temperature of the fungus on potato dextrose agar was $30^{\circ}C$. Sporangiophores were $12{\sim}26\;{\mu}m$ in width. Sporangia were globose or hemispheric, white at first and changed gradually to black, and $83{\sim}195\;{\mu}m$ in size. Columella were hemispheric, and $72{\sim}125\;{\mu}m$ in size. Sporangiospores were irregular round or oval, brownish-black and $9{\sim}20{\times}7{\sim}8\;{\mu}m$ in size. On the basis of symptom, mycological characteristics and pathogenicity to banana, the causal fungus was identified as Rhizopus stolonifer. This is the first report of Rhizopus soft rot by R. stolonifer on banana in Korea.

• The Korean Journal of Mycology
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• v.36 no.2
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• pp.199-202
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• 2008

Rhizopus soft rot caused by Rhizopus stolonifer occurred on melon (Cucumis melo L.) in the box at Jinju City Wholesale Market of Agricultural Products at Gyeongnam province in Korea. The infected fruits were rapidly water-soaked, softened, black and eventually rotted. The symptoms were infected from wounds at harvest time. The colony were white to light brown, formed much sporangiospores. The optimum temperature of the fungus was $30^{\circ}C$. Sporangia were globose or hemispheric, white at first and gradually to black, and $80{\sim}195\;{\mu}m$ in size. Sporangiophores were $12{\sim}24\;{\mu}m$ in width. Columella were hemispheric, and $70{\sim}90\;{\mu}m$ in size. Sporangiospores were irregular round or oval, brownish-black and $9{\sim}20\;{\times}\;6{\sim}8\;{\mu}m$ in size. On the basis of symptom, mycological characteristics and pathogenicity to melon, the causal fungus was identified as Rhizopus stolonifer (Ehrenb.) Vuill.. This is the first report of Rhizopus soft rot by R. stolonifer on melon in Korea.