• The Korean Journal of Mycology
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• v.22 no.4
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• pp.325-331
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• 1994

White-rot fungus, Schizopora paradoxa did not produce Mn-peroxidase and glucose oxidase without manganese. But, in high concentration of manganese (40 ppm), the activities of both enzymes were higher than those in basal concentration of manganese (11.15 ppm). Unlike the activities of the enzymes, mycelial mass was the same level as the control culture (11.15 ppm manganese) through out the culture period, depending on the concentration of manganese. The same experiments were carried out for the effect of copper and veratryl alcohol added to the culture. The results were not consistent dependent on the concentration of copper and veratryl alcohol, respectively. The involvement of cAMP in the correlative production of MNP and GOX was investigated. In this study, addition of atropine to the culture resulted in a concomitant inhibition of production of MNP and GOX, depending on the concentration of inhibitor added.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.4
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• pp.7-17
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• 1997

균체가 생산하는 laccase 효소가 다방면으로 이용되면서, 이 효소를 균체로부터 대량으로 생산하고 분리.정제하여야 할 필요성이 대두되고 있다. 아울러 이 효소의 활성을 유도하기 위한 inducer 로서 2,5-xylidine 이 주로 사용되고 있는바, 이 xylidine 의 유독성이 인정되면서 사람에게 독성을 주지 않는 환경친화적 inducer의 검색이 필요하게 되었다. 본 연구에서는 백색부후균 Cerrena unicolor가 분비하는 laccase 효소의 유도를 위한 inducer로서 ferulic acid를 사용하였으며, 균체로부터 생산 및 분리된 laccase 효소의 정제특성을 구명코자 하였다. 본효소(constitutive enzyme)로서 I 및 II를, ferulic acid를 inducer로 사용한 경우 inducing 효소 III을 분리.정제하였다. 본 효소 I 및 II의 Michaelis 정수는 각각 737 M, 716 M 이었고, inducing효소 III은 167 M 로서, 기질에 대한 높은 친화성을 보여주고 있다. 분자량도 각각 65 kD, 63 kD 였으며, inducing효소 III은 59 kD 였다. 두효소 모두 15-19%의 당 및 단백질분자당 4M의 동(Cu)을 함유하고 있었다. 정제효율은 효소 I 및 II가 10.1%, 9.4% 였으며, III은 3.2% 였다. 모든 효소의 최적 pH 는 5.5였으며, 최적온도는 비교적 높은 $40^{\circ}C$였다.

• Plant Resources
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• v.3 no.2
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• pp.110-117
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• 2000

The recycling method of enokitake cultural waste and the potentiality of second flush for enokitake were determined, because this fungus is not as prolific as the more commonly cultivated white rot fungi in the conversion of sawdust to mycelial mass. The mycelial growth of F. velutipes on several substrates, variously treated with rice bran was promoted at ratios of 10-20% (w/w) on all substrates, but suppressed at above ratios, although some difference was there. The mycelial densities generally increased correlated to the supplementation contents of rice bran. It could be concluded that F. velutipes preferred mild acidic to acidic conditions for mycelial growth, considering that the mycelial growth rate was highest on waste of pH 6.01, treated with 0.1 % Ca(OH)$_2$ and on populus mixed waste of pH 6.02, non treated. The ranges of substrate bulk densities, which was pertinent for mycelial linear growth were from B.D. (g/cc) 0.17 to 0.23 on waste and populus mixed waste all. The pertinent contents of rice bran supplementation in bottle cultivation was from 20 to 30% on waste and 20% on populus mixed waste, considering the requried duration for pinheading and fruiting yields. Standard bulk density for filling and utilizing the waste and populus mixed waste for commercial f. velutipes cultivation were B.D.(g/cc) 0.19 ~ 0.23, and 0.23~ 0.25, which could be conversed to 510~ 540g/900m1 and 520~ 570g/900m1, respectively, The second flush of F. velutipes was tried and the re-inoculation by sawdust and liquid spawn showed somewhat good results, indicating the potentiality of second crop and suggesting further research for it.

• Journal of Microbiology
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• v.45 no.4
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• pp.333-338
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• 2007

Intracellular NADH:quinone reductase involved in degradation of aromatic compounds including lignin was purified and characterized from white rot fungus Trametes versicolor. The activity of quinone reductase was maximal after 3 days of incubation in fungal culture, and the enzyme was purified to homogeneity using ion-exchange, hydrophobic interaction, and gel filtration chromatographies. The purified enzyme has a molecular mass of 41kDa as determined by SDS-PAGE, and exhibits a broad temperature optimum between $20-40^{\circ}C$, with a pH optimum of 6.0. The enzyme preferred FAD as a cofactor and NADH rather than NADPH as an electron donor. Among quinone compounds tested as substrate, menadione showed the highest enzyme activity followed by 1,4-benzoquinone. The enzyme activity was inhibited by $CuSO_4,\;HgCl_2,\;MgSO_4,\;MnSO_4,\;AgNO_3$, dicumarol, KCN, $NaN_3$, and EDTA. Its $K_m\;and\;V_{max}$ with NADH as an electron donor were $23{\mu}M\;and\;101mM/mg$ per min, respectively, and showed a high substrate affinity. Purified quinone reductase could reduce 1,4-benzoquinone to hydroquinone, and induction of this enzyme was higher by 1,4-benzoquinone than those of other quinone compounds.

• Journal of the Korean Wood Science and Technology
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• v.51 no.3
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• pp.183-196
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• 2023

Recently, the morphological and molecular features of five stain fungi infecting rubberwood (Hevea brasiliensis), namely Paecilomyces maximus, Paecilomyces formosus, Penicillium crustosum, Paecilomyces lecythidis and Aspergillus chevalieri, have been studied. Prior to this study, the authors revealed that catechin from gambir (Uncaria gambir) could inhibit the growth of the white-rot fungus Schizophyllum commune, and it was important to determine the bioactivity of the aforementioned agent against A. chevalieri. The efficacy of the biocidal agent was examined using a laboratory wooden block test. Rubberwood blocks, 8 mm in thickness, 20 mm in width, and 30 mm in length, were impregnated with catechin solution at concentrations of 6%, 9%, 12%, and 15% (w/v) using the vacuum-pressure method, and their bioactivity was monitored over three weeks through visual and scanning electron microscope assessment of fungal growth as well as the discoloration intensity of the wood samples. The results showed that catechin treatment increased the resistance of wood samples to A. chevalieri. Overall, the higher the catechin concentration, the lower the fungal growth. The lowest fungal growth was observed in the wood samples treated with 12% and 15% catechin (score of 0), demonstrating no discoloration. In contrast, the fungal growth score of the untreated wood samples reached 4, indicating severe discoloration. Catechins appear to be adequate biofungicides against stain fungi in rubberwood.

• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.82-88
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• 1984

Fruit rot and blister canker, a disease of apple occurring severely in Korea has been studied for correct identification of the syndrome In fruit and apple trees. Among the fungi isolated from blister cankers, rough barks or fruits showing rotting of 7 different host species were Botryosphaeria berengeriana (pycnidial stage. Dethiorella mali), Penicillium expansum and Alternaria sp. from apple rots and Phomopsis sp. from pear fruit rots. The most dominant isolates were B. berengeriana. Ten isolates of D. mali were grouped in to two conidial types based up mycelial growth rate, growth habits and mycelial coloration on PDA. None of 10 isolates was chromogenic. Pycnidia in apple stems, stromatic, dark brown, globose or subglobose and the measuring were $103.5-287.5{\mu}\times92.0-287.5\mu$. The pycnidia contained hyaline, nonseptate, fusiform conidia. The sizes of pycnidiospore of isolates obtained from apple twig were $4.3-7.2{\mu}\times20.0-31.5{\mu}(average\;5.9\times25.4\mu)$. Some conidia of this fungus from apple, pear, peach and ornamental cherry showed 1-,2-,3-septate before or during germination. Microconidia were observed in pycnidia on PDA and fruit lesion of inoculated host. Symptoms on leaves and fruits were contoured brown spots when inoculated. Wart-like protuberance were formed on the surface of apple and pear. Canker appeared on branches of peach and ornamental cherry inoculated.

• Journal of Mushroom
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• v.16 no.4
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• pp.299-303
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• 2018

Flammulina velutipes, which is a white rot fungus, is a commercially important edible mushroom and is produced in large quantities with the help of an automated and mechanized cultivation system in Korea. F. velutipes has the lowest distribution rate among domestic cultivars, estimated at about 20 percent. As most white cultivars of F. velutipes produced and exported to Korea were introduced from Japan, farmers pay large amounts of royalties. Therefore, we have developed a new, purely domestic cultivar, "Baeke," to substitute for Japanese cultivars, which has improved storage characteristics for export. Baeke was bred by mating two monokaryotic strains isolated from ASI 4216-18 (Hansol) and ASI 4217-26 (Baekjung). Baeke showed faster mycelial growth and higher mycelial density upon incubation for seven days at $25^{\circ}C$ on PDA media than the control variety. The mycelial growth of Baeke was even maintained at $30^{\circ}C$ unlike the control. The lengths of pilei and stipes in Baeke harvested in the optimal stage were $11.2{\pm}0.5mm$ and $125{\pm}5.4mm$, respectively, and they were $11{\pm}0.5mm$ and $141.9{\pm}5.7mm$, respectively, in the control harvested in the optimal stage. The yields of Baeke ($257.4{\pm}13.5g$) and control ($270.7{\pm}17.8g$) per 1,100ml in bottle cultivation showed no significant difference. Overall, our results showed that Baeke was at par with foreign varieties of Flammulina velutipes in terms of quality and yield and had a uniformly shaped fruitbody, which added to its commercial value.

• Resources Recycling
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• v.18 no.5
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• pp.52-62
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• 2009

This research was carried out to formulate environmentally friendly wood preservatives with okara and to investigate the effects of the acid concentration used for the hydrolysis of okara and salt type on the decay resistance of the preservatives. Okara-based preservatives were formulated with okara hydrolyzates, which were prepared with 0, 1%, and 2% sulfuric acid at $25^{\circ}C$ for 1 hr, and salts such as copper chloride and/or sodium borate. The preservatives were treated into wood blocks by vacuum-pressure method, and then the treated wood blocks were leached in $70^{\circ}C$ hot water for 72 hrs. The fungal treatments of the leached wood blocks were conducted by brown-rot fungus, Tyromyces palustris, and white-rot fungus, Trametes versicolor, to examine the decay resistance of the preservatives. As the acid concentration used for hydrolysis of okara increased, the treat-ability and decay resistance of the preservatives were improved, which the leachability was decreased. Wood blocks treated with the okara/copper or okara/copper/borax, showed very good decay resistance against T. palustris and T. versicolor. However, wood blocks treated with the okara/borax and okara-free preservative solutions, were observed the fungal decay by T. palustris. The optimal conditions for the preparation of okara-based wood preservatives were formulated with okara hydrolyzed with 1% sulfuric acid, copper chloride and borax.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.33-40
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• 2009

From 2006 to 2008, natural habitat of Sparassis crispa were surveyed for investigating ecological conditions at sixteen different sites in Korea. The investigated sites showed very wide altitudinal distribution ranged from 240 meters to 1,100 meters above the sea level. In general, S. crispa showed distinct feature of heart-rot fungi as it occurs on soils around the stems of larch (Larix kaempferi) and Korean white pine (Pinus koraiensis). But it also could be found on stems or on the stumps of dead trees, which indicated that the fungus might have several invasion routes and capabilities to grow on various ecological conditions. All of the sixteen sites were pure stands consisted with conifers such as larch or Korean white pine. The dominant tree layer showed $15.3{\sim}38.0$ meters for tree heights, thicker than twenty centimeters for the diameter at breast height (DBH), and all of them were older than thirty years. Since the stands were pure stand, species diversity of trees in the sites was extremely low. While the dominant tree layer showed only pure coniferous stand, the co-dominant tree layer, shrub layer and herbaceous layer showed more diverse features with higher Shannon-Wiener (H') indices. Soil texture of thirteen sites among sixteen investigated sites were loamy soils, and the contents of organic matter in soil were more or less higher than general forest soils in Korea with $3.79{\sim}14.32%$. The cation exchange capacity (CEC) was also relatively higher than general forest soils with $16.1{\sim}27.2$ cmol+/kg. The data indicated that the cauliflower mushroom occurring sites were relatively fertile than general forest soils. The soils were acidic with pH ranged from 4.2 to 5.2, which were typical features for conifer stands in Korea.

• 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 ($9.14{\pm}0.3U/mL$).