• The Korean Journal of Mycology
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• v.29 no.1
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• pp.47-51
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• 2001

Obesity and lipid metabolism of SD rats were studied with an edible Nigerian mushroom, namely, Lentinus tuber-regium (Fries) Singer. Experimental diets prepared with Lentinus tuber-regium (LTR) instead of carbohydrates were fed to SD rats for 6 weeks. Body weights gain were decreased (3.2% and 29.3%, respectively) In LTR-50 and LTR-100 groups, whereas food intakes were significantly increased (24.5% and 40.7%, respectively) compared with control group. Feed efficiencies were significantly decreased (22.2% and 49.8%, respectively) in these two LTR groups, whereas gross efficiencies (GE) were increased (9.9% and 10.4%, respectively) compared with control group. The ratios of diet intake (DI)/metabolic body size (MBS) were remarkably increased (50.3% and 136.1%, respectively) in these groups. Triglyceride and LDL-cholesterol levels were significantly decreased (22.4% and 32.6%, 8.3% and 12.7%, respectively) in these two groups, but HDL-cholesterol levels were desirably increased by $3{\sim}10%$ in LTR-added groups. Atherogenic indices (Als) were significantly decreased about $8{\sim}13%$ in LTR-added groups compared with control group. These results suggest that an edible mushroom, Lentinus tuber-regium may inhibit obesity in above 50%-LTR by increasing a diet intake, GE and DI/MBS ratio, but may also effectively modulate a chronic degenerative diseases by improving a lipid metabolism.

• The Korean Journal of Mycology
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• v.29 no.1
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• pp.41-46
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• 2001

Oxidative stress and defense system of SD-rats were studied with an edible Nigerian mushroom, namely, Lentinus tuber-regium (Fries) Singer. Experimental diets prepared with Lentinus tuber-regium (LTR) instead of carbohydrates were fed to SD rats for 6 weeks. Hydrolxyl radical $({\cdot}OH)$ formations were significantly inhibited (21.7% and 16.4%, respectively). In LTR-50 and LTR-100 groups used instead of carbohydrates, and hydrogen peroxide and nitric oxide (NO) were also significantly inhibited by 10%, and $6{\sim}10%$, respectively compared with control group, but there was no significant changes in superoxide radical $({O_2}^-)$ formations in these groups. Lipid peroxide (LPO) and oxidized protein (OP) levels as an oxidative stress were desirably inhibited ($6{\sim}12%\;and\;5{\sim}13%$, respectively) in these LTR groups compared with control group. Superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase (CAT) activities were significantly increased ($15{\sim}50%,\;10{\sim}25%\;and\;60{\sim}90%$, respectively) in these LTR groups. These results suggest that an edible mushroom, Lentinus tuber-regium may inhibit an oxygen radicals and oxidative stresses, but may also effectively modulate an aging processes.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.281-294
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• 2018

Molecular analysis using the internal transcribed spacer region sequences revealed that the strains used in this study, which were formerly identified as Panellus serotinus, are Panellus edullis. After Universal Fungal PCR Fingerprinting (UFPF) analysis, eight strains of P. edulis were divided into two groups. We conducted fundamental research on mycelial growth and sawdust cultivation to understand the cultural characteristics of eight wild P. edulis strains collected from Korean forests. All strains showed faster and denser mycelial growth on potato dextrose agar (PDA) than on other media (malt extract agar, Sabouraud dextrose agar). Optimal conditions for mycelial growth were: $20^{\circ}C$ on PDA, $25^{\circ}C$ on potato dextrose broth (PDB), and pH 5~8 on PDB at $25^{\circ}C$. Two strains (NIFoS 2407, 3993) were selected as excellent strains based on mycelial growth and density on PDA. NIFoS 2792 showed high cellulase activities on carboxymethyl cellulose (CMC) agar, and NIFoS 2387 and 2804 exhibited high laccase activities on ABTS-containing agar media. The mycelial growth of P. edulis was the fastest on Quercus acutissima and Q. mongolica sawdust media, and mycelial density was the highest on Quercus spp. sawdust-containing media. Sawdust cultivation of P. edulis was successful. The conditions were 80~85 days of cultivation period after spawn inoculation, 10~11 days for primordial formation at $17{\sim}18^{\circ}C$, and 15~20 days for fruiting growth. NIFoS 2804 and 3993 were selected as good strains in terms of cultivation period and mushroom production. These results could be useful for the artificial cultivation of P. edulis.

• The Korean Journal of Mycology
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• v.31 no.2
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• pp.59-66
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• 2003

Laccase produced by Pycnoporus cinnabarinus SCH-3 isolated from Korea was partially purified using ultrafiltration, anion exchange chromatography and affinity chromatography, The laccase was produced as the predominant extracellular phenoloxidase during primary metabolism. Neither lignin peroxidase nor manganese-dependent peroxidase were detected in the culture fluid. In order to examine the effect of inducers in laccase production, 2,5-xylidine was added in the culture of Pycnoporus cinnabarinus SCH-3. Addition of 2,5-xylidine enhanced 25-fold laccase production. Purified laccase was a single polypeptide having a molecular mass of approximately 66 kDa, as determined by SDS-polyacrylamide gel electrophoresis, and carbohydrate content of 9%. $K_{m}\;and\;V_{max}$ values for laccase with ABTS [2,2-azinobis (3-ethylbenzthiazoline 6-sulfonic acid)] as a substrate (Lineweaver-Burk plot) was determined to be $44.4{\mu}M\;and\;56.0{\mu}mole$, respectively. The optimal pH for laccase activity was found to be 3.0. The enzyme was very stable for 1 hour at $60{\circ}C$. Half-life ($t_{1/2}$) of the enzyme was about 10 min at $80{\circ}C$. Spectroscopic analysis of purified enzyme indicated that the enzyme was typical of copper-containing protein. Substrate specificity and inhibitor studies for laccase also indicated to be a typical fungal laccase. The N-terminal amino acid sequence of the P. cinnabarinus SCH-3 laccase showed 94% of homology to the N-terminal sequences of laccases from P. cinnabarinus PB and P. coccineus.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.149-157
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• 2015

We examined taxonomic characteristics and safety of eight Nuruk molds that are widely used for making soybean paste, soy sauce and alcoholic beverages in Korea. HK1 from Hakyeong Fermentation Co., SW101 from Suwon Fermentation Co., CF1001, CF1002, CF1003 from Chungmoo Fermaentation Co. and KACC 93210 are yellow-Nuruk molds, and SW201 from Suwon Fermentation Co. and CF1005 from Chungmoo Fermentation Co. are white-Nuruk molds. Six strains of yellow-Nuruk molds were identified as Aspergillus oryzae. HK1, SW101, CF1001 and CF1003 of yellow-Nuruk molds have middle length of stipes ($711{\sim}1,121{\mu}m$), and CF1003 (for sake) produced less conidia and more hyphae than HK1, SW101 and CF1001 (for soybean paste). CF 1002 used for soy sauce has shorter stipes ($543{\mu}m$) and is clustered into IBLB-group based on omtA gene analysis although the other yellow-Nuruk molds are clustered into ICAo group. KACC 93210 isolated from traditional Korean Meju has very short stipes (average $270{\mu}m$), and showed velvety colonies although the others showed floccose colonies. The strain has different DNA sequences of omtA gene from other strains in NCBI GenBank as well as strains used in Korea, suggesting that it is unique from other strains published. SW201 and CF1005 of white-Nuruk molds were identified as Aspergillus luchuensis or A. luchuensis mut. Kawachii that is known as safe, non-toxigenic fungus. The six strains of yellow-Nuruk molds did not produce mycotoxins including aflatoxin, cyclopiazonic acid, and sterigmatocystin. Therefore, eight strains of Nuruk molds used for making soy sauce, soybean paste and alcoholic beverages in Korea were proved to be safe in this study.

• The Korean Journal of Mycology
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• v.5 no.1
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• pp.7-12
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• 1977

For this study 3 samples of the home-made meju and 3 samples of the improved meju were selected according to their characteristics. A total of 25 strains of true fungi were isolated from the samples of the home-made meju and identified by the Key of Alexopoulos and Raper, using a strain Aspergillus oryzae A-113 as a control. Amylolytic and proteolytic enzyme activities of the isolated strains were investigated ana the results obtained were as follows. 1. The 25 strains from the home-made meju were identified into 2 Aspergillus oryzae, 14 Asp. flavus, 6 Penicillum spp. 1 Candida sp 1 Spicaria sp and 1 Rhizopus sp. 2. The 3 strains from the improved meju were all identified as Aspergillus oryzae. 3. Aspergillus flavus, A-B, from the home-made meju was found to he the strongest strain in ${\alpha}-amylase$ activity and also to be similar to the strains of Aspergillus orzae from improved meju. 4. Aspergillus flavus, A-7, from the home-made meju was found to be the strogest strain in ${\beta}-amylase$ activity and stronger than that from the improved meju. 5. Aspergillus flavus B-3, was found to be the strongest strain in protease activity and stronger than that from the improved meju. 6. Some of the strains from the home-made meju turned out to be harmful strains, such as Penicillium spp. which secrete antibiotics, Asp. flavus which secretes mycotoxin, Candida sp which causes skin diseases, Spicaria sp. which is a insect pathogen. 7. Rhizopus sp was also found but it has not been proved to be harmful.

• The Korean Journal of Mycology
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• v.10 no.1
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• pp.33-39
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• 1982

Carpophores of ten Korean strains of Lentinus edodes (Berk.) Singer, an antitumor polysaccharide producing fungus, were extracted with 0.1N NaOH solution. The extracts were dialized for seven days in distilled water and lyophilized to produce crude polysaccharide powders. Thus obtained crude polysaccharide samples were assayed for sugar contents by colorimetric method with anthrone reagent. Among ten strains examined Lentinus edododes-DMC7 was found to be the richest strain in polysaccharide content of carpophores. By shake culture experiment for biomass production, L. edodes-DMC7 was found to be the second most productive strain among seven strains examined. Cultural characteristics of L. edodes-DMC7 were investigated by shake culture method. The best result was obtained when L. edodes-DMC7 was cultured in the medium containing glucose 8g, starch 80g, yeast extract 12g, $KH_2PO_4\;0.87g,\;MgSO_4{\cdot}7H_2O\;O.5g,\;CaCl_2\;0.3g,\;FeSO_4{\cdot}7H_2O\;10mg\;ZnSO_4{\cdot}7H_2O\;4mg,\;CuSO_4{\cdot}5H_2O\;lmg,\;MnCl_2{\cdot}4H_2O\;7mg\;per\;11\;at\;28^{\circ}C$, 180 rpm, for 12 days. Thus thirty-three grams of dry mycelia was obtained per one liter of medium.

• The Korean Journal of Mycology
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• v.3 no.1
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• pp.1-19
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• 1975

Since the importance of casing in fruit body formation of Agaricus bisporus has been emphasized, physico-chemical characteristics of casing materials were discussed by many workers and a mixture of peat and mineral soil as proper casing material has been adopted in many of mushroom growing countries. Because of limited resources of peat in Korea, it is necessary to find practical performance and substitutional materials for casing. The effect of casing on mycelial growth and mushroom yield of A. bisporus varied with materials, its combination and practices etc. The experiments to be discussed in this paper are concerned with pH and Ca of casing material which influence A bisporus, and changes of physico-chemical characteristics with mixing ratio of casing materials and its effect on A. bisporus. The optimum range of moisture content of each material, management of watering and application of physico-chemical characteristics casing materials was also investigated and re-use of weathered spent compost for casing material was described. 1. The effect of calcium on mycelial growth of A. bisporus at various pH in Halbschalentest showed different results with calcium sources. Best results were obtained around neutrality and fresh weight of fruit bodies grown in the range of pH 7 to 8 was highest among the tested levels. 2. Available moisture, pore space, organic matter, cation exchangeable capacity and exchangeable cation was increased by an increase of mixing ratio of peat in casing materials, while an adverse effect was obtained by addition of sand. 3. Mycelial growth on clay loam was more rapid at a lower bulk density of 0.75g/cc and at 20% moisture content on a dry weight basis at the same bulk density. 4. Mixing ratio of casing materials, 60 to 80 per cent by volume of peat mixed with 20 to 40 per cent of clay loam produced the highest yield of fresh fruit bodies and sand the lowest. However, per cent of open cap was highest in peat and lowest in sand. 5. Days required for fruit body initiation was shortened in mixtures of peat and clay loam by one to three days compared with other materials and the formation of flushes was clear. 6. The effect of some physico-chemical characteristics of casing materials on the fresh weight of fruit bodies were estimated by a multiple regression equation; Y=-923.86+$8.18X_1+8.04X_2+7.90X_3+0.12X_4+2.03X_5-0.82X_6-0.54X_7$ where $X_1,X_2,X_3,X_4,X_5,X_6,X_7$ are sand, silt, clay, available moistuer, porosity, organic matter and exchangeable cation respectively. The productivity of certain casing material could be predicted from this equation. 7. Fresh weight of fruit bodies was positively correlated with porosity exchangeable cation, organic matter, available moisture, silt and clay of materials; while sand was negatively correlated. On the contrary, sand was the unique factor reducing per cent of open cap. 8. Distribution of three phases of high productive casing material was concentrated in the range of 10 to 30 per cent solids, 15 to 30 per cent liquids, and 50 to 60 per cent in air volume. 9. Fresh weight of fruit bodies from peat was not affected with heavy watering but in clay loam and sandy loam severe crop losses occurred. Fresh weight of individual fruit was increased and open caps were decreased with heavy watering but light watering resulted in adverse effects: its effect was especially great in peat. 10. Optimum range of moisture content by weight on a dry basis was different with each casing material. To maintain optimum moisture content concerned with yield of fruit bodies and open cap, sandy loam and peat mixtures required daily watering of 0.6, 0.6 to 1. 2 and 1.2 to 2.4 liters per $3.3m^2$ of bed area, respectively. 11. Maximum yield of fruit body was recorded in the range of pF 2. 0 to 2. 5 of casing materials if organic matter content was below 4.2 per cent and in pF 1. 3 to 1.8 if above 7.1%. 12. pF curve of a certain casing material could be draws from moisture content at various pF values by multiple regression equations provided texture, organic matter and calcium of the casing material are given. Optimum moisture range of the casing materials also could be estimated by the equation. 13. It was possible to improve the phyico-chemical characteristics of clay loam and sandy loam by addition of weathered spent compost although the effect was less than in the case of peat. Fresh weight of fruit bodies wsa increased by addition of weathered spent compost but its effect was not as remarkable as peat. Accordingly, further studies will be required.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.134-140
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• 2003

Wild Mushrooms collected in Mt. Halla of Jeiu Island around altitude of $200{\sim}1000\;m$ from 1999 to 2000 were studied to investigate utilization as the natural breeding sites by wild drosophilids. Thirty-five mushroom species belonging to the 19 genera of 12 families from 2 orders were used as natural breeding sites by drosophilids. Adult flies emerged from 14 species of mushrooms belonging to the 11 genera of 8 families from 2 orders were identified. From the rest of 21 species of mushrooms, only larvae or/and pupae were reaped. Among 35 species of mushrooms, 34 species belonged to order Agaricales and only one species, Sarcodon scabrosum, belonged to order Aphyllophorales. In terms of composition of mushroom families, total 35 species belonging to 12 families were composed of 10 species of Russulaceae, 6 species of Amanitaceae, 4 species of each Tricholomataceae and Agaricaceae, 3 species of Boletaceae, 2 species of Strophariaceae and each one species of rest 6 families. Concerning the composition of the genus, 35 species belonging to 11 genera were composed of 8 species of Russula, 6 species of Amanita, 4 species of Agaricus, 2 species of Lactarius, and each one species of rest 7 genera. In terms of the mushroomsize preference of drosophilid flies for breeding sites, most flies preferred comparatively large mushrooms above 5 cm of pileus size in diameter, Fourteen species of drosophilids were identified as mushroom-breeding species. Among these, one and five species belonged to genera Mycodrosophila and Hirtodrosophila respectively, The genus Drosophila included the most abundant 8 species. Drosophila bizonata and Hirtodrosophila sexvittata bred on 6 species of mushrooms respectively, D. unispina bred on 3 species of mushrooms, rest species of Drosophila bred on one or two species of mushrooms. From the result of this study and other literatures, it could be presumed that much more mushroom species could serve as the natural breeding sites for greater number of drosophilid species than those examined in this study on Jeju Island.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.10-19
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• 1997

Fusarium wilt of radish (Raphanus sativus L.) is caused by the Fusarium oxysporum f. sp. raphani (FOR) which mainly attacks Raphanus spp. The pathogen is a soil-borne and forms chlamydospores in infected plant residues in soil. Infected pathogen colonizes the vascular tissue, leading to necrosis of the vascular tissue. Growth promoting beneficial organisms such as Pseudomonas fluorescens WCS374 (strain WCS374), P. putida RE10 (strain RE10) and Pseudomonas sp. EN415 (strain EN415) were used for microorganisms-mediated induction of systemic resistance in radish against Fusarium wilt. In this bioassy, the pathogens and bacteria were treated into soil separately or concurrently, and mixed the bacteria with the different level of combination. Significant suppression of the disease by bacterial treatments was generally observed in pot bioassy. The disease incidence of the control recorded 46.5% in the internal observation and 21.1% in the external observation, respectively. The disease incidence of P. putida RE10 recorded 12.2% in the internal observation and 7.8% in the external observation, respectively. However, the disease incidence of P. fluorescens WCS374 which was proved to be highly suppressive to Fusarium wilt indicated 45.6% in the internal observation and 27.8% in the external observation, respectively. The disease incidence of P. putida RE10 mixed with P. fluorescens WCS374 or Pseudomonas sp. EN415 was in the range of 10.0-22.1%. On the other hand, the disease incidence of P. putida RE10 mixed with Pseudomonas sp. EN415 was in the range of 7.8-20.2%. The colonization by FOR was observed in the range of $2.4-5.1{\times}10^3/g$ on the root surface and $0.7-1.3{\times}10^3/g$ in the soil, but the numbers were not statistically different. As compared with $3.8{\times}10^3/g$ root of the control, the colonization of infested ROR indicated $2.9{\times}10^3/g$ root in separate treatments of P. putida RE10, and less than $3.8{\times}10^3/g$ root of the control. Also, the colonization of FOR recorded $5.1{\times}10^3/g$ root in mixed treatments of 3 bacterial strains such as P. putida RE10, P. fluorescens WCS374 and Pseudomonas sp. EN415. The colonization of FOR in soil was less than that of FOR in root part. Based on soil or root part, the colonization of ROR didn't indicate a significant difference. The colonization of introduced 3 fluorescent pseudomonads was observed in the range of $2.3-4.0{\times}10^7/g$ in the root surface and $0.9-1.8{\times}10^7/g$ in soil, but the bacterial densities were significantly different. When growth promoting organisms were introduced into the soil, the population of Pseudomonas sp. in the root part treated with P. putida RE10 was similar in number to the control and recorded the low numerical value as compared with any other treatments. The population density of Pseudomonas sp. in the treatment of P. putida RE10 indicated significant differences in the root part, but didn't show significant differences in soil. The population densities of infested FOR and introduced bacteria on the root were high in contrast to those of soil. P. putida RE10 and Pseudomonas sp. EN415 used in this experiment appeared to induce the resistance of the host against Fusarium wilt.