• Research in Plant Disease
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• v.29 no.1
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• pp.11-22
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• 2023

Resazurin-based microtiter assay was used to evaluate the inhibitory effect of fungicides on the respiration of Colletotrichum acutatum s. lat. 20JDS8 sensitive and 20CDJ6 resistant to strobilurin fungicides. The spores of C. acutatum s. lat. 20JDS8 were inoculated into potato dextrose broth (PDB) at densities of 1x10⁴, 1x10⁵ and 1x10⁶ spores/ml, respectively. The relative fluorescence unit (RFU) of all treatments inoculated at each spore density started to rise after 12 hr of incubation, and were 1,965.5, 5,412.5, and 10,061.0, respectively, after 24 hr of incubation. To evaluate the inhibitory effect of fungicide on the respiration of the pathogen, the spores of the pathogen were inoculated into the PDB and treated with the fungicides 0, 6, 12, and 24 hr after incubation, respectively. After keeping the pathogen culturing for another 24 hr, PrestoBlue reagent was treated into the PDB culturing the pathogen. The RFU of each treatment was examined 1 hr after the reagent was treated. When dithianon, isopyrazam, pyraclostrobin, and fluazinam were treated at high concentrations in the stages of spores (immediately after inoculation [0 hr]), spore germination (after incubation for 6 hr), and hyphal growth (after incubation for 12 hr), the respiration of pathogens was inhibited by 90-100%. When the fungicides were treated after culturing the pathogen for 24 hr, the respiratory inhibitory effects were greatly reduced. With pyraclostrobin-resistant C. acutatum s. lat. 20CDJ6, azxoystrobin, trifloxystrobin and kresoxim-methyl, which have the same mode of action, had very little or no respiratory inhibitory effect in all growth stages of pathogens. Based on the above results, it was thought that the resazurin-based microtiter assay could quickly and accurately evaluate the inhibitory efficacy of the fungicides that inhibited respiration.

• Journal of Mushroom
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• v.5 no.1
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• pp.7-12
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• 2007

All intra-specific hybrids among ASI $2172{\times}2104$, $2172{\times}2307$, $2186{\times}2172$ and $2186{\times}2307$ in P. salmoneostramineus produced pink fruiting bodies as like wild parental types. However, three hybrids of them between ASI 2186 and 2104 were white fruiting bodies. A new commercial strain "Noeul" of Pink Oyster mushroom was developed by intra-specific hyphal anastomosis. It was improved with hybridization between monokaryotic strain derived from ASI 2172 and ASI 2104. The optimum temperature of mycelial growth and fruiting body development were $25{\sim}30^{\circ}C$ and $19{\sim}24^{\circ}C$, respectively. The pileus was bright reddish pink. Commercial strain "Noeul" was as prolific as the more commonly cultivated Pleurotus ostreatus in the conversion of substrate mass to mushrooms using bottle cultivation. Mushroom cultivator can save money for mushroom growing on summer in Korea. Mushrooms should be picked when moderately young, and handled carefully so as to not bruise the brilliantly colored gills. This pink color makes marketing an interesting challenge depending upon the market niche.

• Journal of Mushroom
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• v.12 no.2
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• pp.132-137
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• 2014

Green mold disease caused by Trichoderma species has recently caused considerable damage to oyster mushroom industries in Korea. This disease Trichoderma, Penicillium, Aspergillus, such as in (genus) to be included in a disease caused by a species that collectively the largest incidence and damage is caused by the pathogen Trichoderma genus. T. longibrachiatum, Trichoderma koningii, Trichoderma virens, T. hazianum, T. atroviride, and T. pseudokoningii were detected on oyster mushroom beds and, of them, T. virens, T. hazianum, T. longibrachiatum was the most frequently detected. The knowledge concerning physiological and ecological properties of Trichoderma spp. was essential for their effective control. T. longibrachiatum hyphal growth is very fast, spore formation, and, particularly well-chlamydospore formation characteristics, and reviews are dark green discoloration. T. koningii, fast mycelial growth, aerial hyphae and spores in aerial hyphae formation is concentrated. T. virens, especially if the color change caused by spore-forming, slow, late in infection, the more severe the damage is discovered. T. hazianum fast mycelial growth, white aerial hyphae and late turns dark green. After spore formation hyphae glob of white pustules or tufts on the top of the formation. T. atroviride. aerial hyphae usually the mycelial growth and spore formation in the unlikely event of the formation and smells similar to the smell of coconut is that. Fast T. pseudokoningii mycelial growth, spore formation is formed around the inoculation site, discoloration of the medium color and well formed chlamydospores.

• Korean Journal of Environmental Agriculture
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• v.21 no.4
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• pp.261-268
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• 2002

Biodegradation of monochlorophenols by wood rot fungi such as Daldina concentrica, Trametes versicolor and Pleurotus ostreatus was evaluated by determining their resistance or toxic test and biodegradability. The metabolites of monochlorophenols were also analyzed. Among the three fungi, T. versicolor was the most resistant to 200 ppm of 2-, 3- and 4-chlorophenols, and did not show any inhibitory mycellium growth. But D. concentrica had a little inhibition effect at more than 100 ppm of 3- or 4-chlorophenol. Control cultures of P. ostreatus took even 14 days far the completion of mycellium growth, but the hyphal growth was improved when 2- or 3-chlorophenol were added to the culture. In biodegradation analysis, P. ostreatus showed the highest degradation of 2- or 3-chlorophenol, while T. versicolor was the most effective in 4-chlorophenol. D. concentrica and P. ostreatus slowly degraded 4-chlorophenol. However, T. versicolor had similar degradation capability in the three monochlorophenols, suggesting that the biode- gradation nude is dependent on the fungi as well as the type of monochlorophenol. Several metabolites such as 1,3,5-trihydroxyl benzene, 1-ethyl-1-hydroxyl pentane, 2-propenoicacid, methylmalonic acid and 2-methyl-4-keto-pentan-2-ol were found as products of primary oxidation of 2-, 3- and 4-chlorophenols by intact fungal cultures. fatty acids including tetradecanoic, heptadecanoic and octadecanoic acids were also detected The order of increase of mycellium weight during incubation were P. ostreatus > T. versicolor > D. concentrica. The pH in the culture was not constantly changed depending on incubation days, but the mycellium weight was slightly increased, indicating that the biodegradation of monochlorophenol might have low relationship with the mycellium growth Laccase activities of T. versicolor and P. ostreatus were continuously increased depending on the incubation days, suggesting that the ligninolytic enzyme activity play an important role in the biodegradation of monochlorophenol.

• Journal of Life Science
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• v.13 no.1
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• pp.90-98
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• 2003

An allium rhizobacterium Serratia plymuthica AL-1 was previously selected as a biocontrol agent of allium white rot. The chitinase from S. plymuthica AL-1 produced in medium containing colloidal chitin was purified by ammonium sulfate precipitation (40~70%), affinity adsorption, column chromatography on DEAE-sephadex A-50 and sephadex C-200 gel filtration. The enzyme was purified 10.8-fold with a yield of 7.3% from the starting culture broth. The purified chtinase gave a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis, it's molecular weight was estimated to be 55 kDa. The optimum pH and temperature of the purified enzyme were pH 5.5 and $55^{\circ}C$, respectively and it is stable up to $50^{\circ}C$ and maintains around 90% of its activity for 60min. The enzyme were activated by $Ca^{2+}$, $Mn^{2+}$ and $Mg^{2+}$ and inhibited by $Cu^{2+}$, SDS, $\rho$-CMB, MIA, respectively. The purified chitinase showed broad spectrum of antifungal activities against plant pathogenic fungi Sclerotium cepivoruin, Alternana alternnta, Colletotrichum glceosporioidrs, Phoma sp., Sclerotinia sclerotiorum, Stemphylium solani, Fusarium oxysporium f. sp. niveum but rarely inhibited Phytophthora capsici and Pythium ultimum.. The purified chitinase from S. plymuthica AL-1 caused swelling, lysis, deceleration and degradation of the hyphal tips of S. sczerotiorum causing allium white rot. It suggest that S. prymuthica AL-1 chitinase play an important part in the bifunctional chitinase / lysozyme activity.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.246-250
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• 2017

Sclerotium rot was observed on mungbean (Phaseolus radiatus L.) plants cultivated in the exhibition field of Gyeongsangnam-do Agricultural Research and Extension Services in September 2015. The progression of rot was initially observed as water-soaked lesions on several parts of the affected plant. Severely infected plants were blighted and eventually died. White mycelial mats spread over the lesions and numerous sclerotia formed on stems 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 $30^{\circ}C$ and the hyphal width was $4{\sim}8{\mu}m$. Typical clamp connections were observed on the hyphae of fungus grown on PDA. For molecular identification, the complete internal transcribed spacer (ITS) ribosomal DNA (rDNA) of the causal fungus was sequenced and analyzed. Based on the mycological characteristics, ITS rDNA sequence analysis, and pathogenicity to host plants, the fungus was identified as Sclerotium rolfsii. This is the first report of Sclerotium rot on mungbean caused by S. rolfsii in Korea.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1272-1277
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• 2007

Comparison of fruit bodies of Pleurotus ostreatus cultivar chunchu No .2 grown on the sawdust, rice straw and cotton waste substrates revealed differences in the pattern of differentiation of hyphal compartments. Required period for primordium induction of fruit bodies grown on sawdust substrate was 13 days. Physical structure shown as hardness of stipes grown on the sawdust substrate, fruit bodies were harden than control. Pileocystidia were well developed on the surface of pileus in the fruit body cultivated on rice straw. Microstructures of fruit body grown on the sawdust and cotton wastes substrates shown fast-discharge of basidiospore and sytoms ageing. Hyphae of fruit bodies formed on sawdust substrate had less stainable cytoplasmic material and many more vacuoles than hyphae of fruit bodies formed on synthetic substrate with 50% of pine sawdust, 30% of cotton seed hull and 20 of beet pulp(control).

• Journal of Mushroom
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• v.4 no.3
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• pp.83-87
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• 2006

A new commercial strain "Gumbit" of golden oyster mushroom was developed by hyphal anastomosis. It was improved with hybridization between monokaryotic strain derived from ASI 2295 and ASI 2703. The optimum temperature of mycelial growth and fruiting body development were $25{\sim}30^{\circ}C$ and $19{\sim}24^{\circ}C$, respectively. The pileus was golden to brilliant yellow color. Commercial strain "Gumbit" was not as prolific as the more commonly cultivated Pleurotus ostreatus in the conversion of substrate mass to mushrooms. However, cultivator can save money for mushroom growing on high-temperature season as like summer in Korea. Since picking individual mushrooms is tedious and often damages the fragile fruiting bodies compared with other species of oyster mushrooms.

• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.206-215
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• 2020

Trichoderma reesei is the major filamentous fungus used to produce cellulase and there is huge interest in promoting its ability to produce higher titers of cellulase. Among the many factors affecting cellulase production in T. reesei, the mycelial phenotype is important but seldom studied. Herein, a close homolog of the Neurospora crassa COT1 kinase was discovered in T. reesei and designated TrCOT1, which is of 83.3% amino acid sequence identity. Functional disruption of Trcot1 in T. reesei by RNAi-mediated gene silencing resulted in retarded sporulation on potato dextrose agar and dwarfed colonies on minimal medium agar plates containing glucose, xylan, lactose, xylose, or glycerol as the sole carbon source. The representative mutant strain, SUS2/Trcot1i, also displayed reduced mycelia accumulation but hyperbranching in the MM glucose liquid medium, with hyphal growth unit length values decreased to 73.0 ㎛/tip compared to 239.8 ㎛/tip for the parent strain SUS2. The hyperbranching phenotype led to slightly but significantly increased cellulase secretion from 24 to 72 h in a batch culture. However, the cellulase production per unit of mycelial biomass was much more profoundly improved from 24 to 96 h.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.130-137
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• 1994

This experiment was carried out to investigate proper conditions for protoplast isolation and regeneration from mycelia of Lyophyllum decastes. Novozym 234(10 mg/ml) with 0.6 M $MgSO_4$ in phosphate buffer(pH 4.0) was proper for protoplast isolation. The optimal reaction time of the mycelium with the lytic enzyme was four hours in shaking condition at 120 strokes per min. When the mycelium of L. decastes was cultured at $24^{\circ}C$ for 5 days, the formation of protoplasts was effective. The liquid medium was more effective for protoplast isolation than the solid medium. In the liquid medium, high yields of protoplasts were obtained from 0.6 M $MgSO_4$ osmotic stabilizer. Protoplasts of L. decastes were regenerated to normal hyphal growth and the regeneration frequency of the protoplasts in the complete agar medium containing Triton X-100(0.0025%) was $5.94{\sim}8.32%$. The regeneration medium stabilized with 0.6 M sucrose was the best for regeneration of the protoplasts. In contrast to protoplast formation, regeneration was inhibited by the inorganic salts used as osmotic stabilizer.