• 한국균학회지
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• 제51권2호
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• pp.101-109
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• 2023

A fungal strain designated KNUF-21-66Q1 was isolated from soil in Chungcheongbuk Province, Korea. Moderate growth of colonies was observed on potato dextrose agar, oatmeal agar (OA), malt extract agar, and cornmeal agar media at 25℃, and the detailed morphology was examined on OA medium. The colonies on OA medium were flat, had entire margin, hyaline, and yellow concentric rings in 3-4 weeks. Conidiomata were pycnidial, solitary or clustered, globose to subglobose, black-brown, and 300-500 ㎛ in diameter. Conidiogenous cells were smooth, hyaline, globose to ampulliform, and 6.0-9.0×3.0-6.0 ㎛ in size (n=15). Conidia were hyaline to pale brown, slightly golden, obovoid to slightly ellipsoidal, smooth, guttulate, and 3.0-4.7×2.1-3.3 ㎛ in size (n=100). The strain was confirmed based on phylogenetic analysis using internal transcribed spacer regions, the partial 28S rDNA of large subunit, and β-tubulin gene sequences. The morphological observations and phylogenetic analysis revealed that the strain KNUF-21-66Q1 was similar to the previously described Paraconiothyrium kelleni. To our knowledge, this is the first report of P. kelleni in Korea.

• Mycobiology
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• 제51권3호
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• pp.186-194
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• 2023

In July 2021, wilting symptoms were observed in adult and seedling hemp (Cannabis sativa L. cv. Cherry Blossom) plants grown in a greenhouse. As the disease progressed, yellowing and wilting symptoms on the leaves developed, resulting in whole plant death. In seedling plants, typical damping-off symptoms were observed. To identify the pathogen, the roots of diseased plants were sampled, surface sterilized, and cultured on potato dextrose agar (PDA) media. From the culture, 4 different fungal isolates were recovered and purely cultured. Each fungal isolate showed distinct growth shapes and color development on malt extract agar, oatmeal agar, sabouraud dextrose agar, and PDA media. Microscopic observation and molecular identification using ribosomal DNA internal transcribed spacer sequencing identified them as 3 Fusarium spp. and 1 Thielaviopsis paradoxa. Additional sequencing of elongation factor 1-alpha and b-tubulin regions of 3 Fusarium spp. revealed that 2 of them are Fusarium solani, and the other one is Fusarium proliferatum. To examine which isolate can act as a causal agent of wilt disease of hemp, each isolate was tested for their pathogenicity. In the pathogenicity test, F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3, but not T. paradoxa AMCF4, were able to cause wilting disease in hemp seedlings. Therefore, we report that F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3 as causal agents of Fusarium wilt of hemp plants. To our knowledge, this is the first report of the wilt disease of C. sativa L. caused by Fusarium spp. in Korea.

• Mycobiology
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• 제30권4호
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• pp.240-243
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• 2002

Embellisia allii causing bulb canker of white garlic(Allium sativum) has been observed on harvested or stored garlic bulbs. Identification of the fungus was determined based on the symptoms and morphological characteristics on in vitro potato dextrose agar(PDA) and malt extract agar(MEA). Colonies were effuse, blackish brown to black, velvety or powdery. Conidia were solitary, almost straight, most commonly ellipsoidal(or subcylindrical) to ovoid, mid to dark brown, smooth, with very dark 1 to 6 transverse(commonly $3{\sim}4$) and occasionally 1 or 2 oblique or longitudinal septa, and $30.4{\times}13.4{\mu}m$(av.). Conidiophores were simple or branched, straight or flexuous, up to 80 ${\mu}m$ long and $5.1{\sim}10.2{\mu}m$ thick. Chlamydospores were developed through enlargement and repeated cellular division of several adjacent hyphal cells to form a complex of thickwalled cells. The conidial measurements of garlic isolates closely matched the previous description of E. allii.

• Mycobiology
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• 제50권4호
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• pp.238-243
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• 2022

Members of the genus Tuber are ectomycorrhizal fungi; this genus includes more than 180 species worldwide. In the present study, the optimal pH, temperature, and medium suitable for the mycelial growth of the Korean truffle, Tuber koreanum, were determined. Mycelium of T. koreanum, isolated from fruiting bodies collected in Korea, was used to investigate the effects of these environmental factors. The results showed that malt extract agar and potato dextrose agar were the most suitable for the mycelial growth of T. koreanum when cultured at a pH of 6.0 at 25 ℃ for 30 days.

• 미생물학회지
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• 제48권1호
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• pp.48-51
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• 2012

세포외 단백질분해효소를 생산하는 신종세균 Chryseobacterium sp. JK1은 토양으로부터 분리되었다. JK1 균주는 $30-35^{\circ}C$에서 skim milk를 첨가한 고체배지상에서 가장 큰 투명환을 보여주었다. 액체배지에서 JK1 균주의 세포생육은 24시간에 최대이었고, 세포외 단백질분해효소의 최대활성은 정지기인 22시간에 560 unit/ml에 도달하였다. Nutrient 배지에 maltose 혹은 glucose, mannitol을 첨가하면 생육이 향상되었지만, 단백질 분해효소 생산은 64-77%로 저조하였다. Skim milk 혹은 beef extract, yeast extract, malt extract, tryptone의 첨가는 향상된 생육과 줄어든 효소생산을 보인 반면, $(NH_4)_2HPO_4$ 또는 $(NH_4)_2SO_4$의 첨가는 저조한 생육과 121-146%의 향상된 효소생산을 보여 주었다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.174-174
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• 1994

항종양 물질의 탐색 및 연구 작업이 미생물을 대상으로 행해져 온것은 이미 오래전부터 이며, 기존의 연구 발표된 것들을 볼때 미생물 스크리닝의 증요성은 점차 증대되어가고 있다. 이에 본 연구에서는 국내 토양에서 방선균 약 1000여주를 분리하여 항종양 물질을 생산하는 방선군의 분리, 동전하고, 그 생산물질의 특성을 밝히고자 하였다. 방선균의 분리는 전국 각지에선 채집한 토양시료 각 1 g 씩을 80 $^{\circ}C$에서 90분간 건조처리한후 멸균된 증류수를 이용하여 각 단계별로 희석하여 Starch nitrate casein agar와 Glycerol asparagine agar를 사용하여 방선균을 분리하였다. 분리된 방선균을 Yeast extract-malt extract 액체 배지에서 7일간(160 rpm/28 $^{\circ}C$) 배양하였다. 여기에서 얻어진 배양액을 이용하여 항종양능을 확인한기 위해서 암세포주인 L1210주와 P388 D$_1$주, 정상 세포주로는 Vero 세포주를 이용한 MTT colorimetric assay를 이용하였다. 이들 실현에 대한 결과로써 S-104, 117, 409의 세 균주의 항종양물질 생산 균주를 분리하였다. 이들 균주가 생산하는 물질들은 기존의 시판 항암제인 Adriamycin에 비해 높게 나타났으며, 이들 균주의 동정은 ISP의 기준에 의하여 행하였다.

• The Plant Pathology Journal
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• 제24권1호
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• pp.87-89
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• 2008

A blue mold on tomato fruit caused by Penicillium oxalicum occurred sporadically in a greenhouse at Gyeongsangnam-do Agricultural Research and Extension Services. Infection usually occurred through wounds or cracks on the fruits. Symptoms began with water soaking lesions, then became watery and softened eventually. Colony of the causal fungus was white at the early growing stage, turned green on Czapek yeast extract agar and malt extract agar. Conidia were ellipsoidal in shape and $2-6{\times}2-4{\mu}m$ in size. Stipes were septate, smooth, thin walled, and $90-280{\times}3-4{\mu}m$ in size. Penicilli were mostly biverticillate. Ramuli were 1-3 groups, smooth, and $10-16{\times}2-3{\mu}m$ in size. Rami were 1-2 groups and $6-30{\times}2-4{\mu}m$ in size. Metulae were 2-3(5) verticils, smooth, and $12-20{\times}3-4{\mu}m$ in size. Phialides were 5-7 verticilate, ampulliform to cylindroidal, smooth, and $8-12{\times}2-3{\mu}m$ in size. Optimum temperature for growth was about $25^{\circ}C$. Pathogenicity of the fungus was proved on tomato fruit according to Koch's postulation. On the basis of mycological and pathological characteristics, the fungus was identified as P. oxalicum Currie & Thom. This is the first report of the blue mold on tomato fruit caused by P. oxalicum in Korea.

• The Plant Pathology Journal
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• 제35권6호
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• pp.674-683
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• 2019

Some species of the Trichoderma genus are reported as the major problem in oak wood mushroom production in Korea. In spite of economic loss by the fungi, scientific information on airborne Trichoderma species is not much available. To generate information for disease management development we analyzed airborne Trichoderma. A total of 1,063 fungal isolates were purely obtained from indoor air sampling of cultivation houses used for oak wood mushroom using sawdust media. Among the obtained isolates, 248 isolates were identified as Trichoderma fungi including T. harzianum, T. atroviride, T. citrinoviride, and T. pseudokoningii, by morphological and molecular analysis. T. harzianum was dominant among the four identified species. All the four Trichoderma species grew fast on solid nutrient media tested (potato dextrose agar [PDA], malt extract agar [MEA], Czapek's Dox + yeast extract agar [CYA] and cornmeal dextrose agar). Compact mycelia growth and mass spore production were better on PDA and CYA. In addition, T. harzianum and T. citrinoviride formed greenish and yellowish mycelium and spores on PDA and CYA. Greenish and yellowish pigment was saturated into PDA only by T. pseudokoningii. These four Trichoderma species could produce extracellular enzymes of sawdust substrate degradation such as β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease. Their mycelia inhibited the growth of oak wood mushroom mycelia of two tested cultivars on dual culture assay. Among of eleven antifungal agents tested, benomyl was the best to inhibit the growth of the four Trichoderma species. Our results demonstrate that the airborne Trichoderma fungi need to be properly managed in the cultivation houses for safe mushroom production.

• Mycobiology
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• 제40권1호
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• pp.53-58
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• 2012

This research is concerned with the fungicidal properties of nano-size silver colloidal solution used as an agent for antifungal treatment of various plant pathogens. We used WA-CV-WA13B, WA-AT-WB13R, and WA-PR-WB13R silver nanoparticles (AgNPs) at concentrations of 10, 25, 50, and 100 ppm. Eighteen different plant pathogenic fungi were treated with these AgNPs on potato dextrose agar (PDA), malt extract agar, and corn meal agar plates. We calculated fungal inhibition in order to evaluate the antifungal efficacy of silver nanoparticles against pathogens. The results indicated that AgNPs possess antifungal properties against these plant pathogens at various levels. Treatment with WA-CV-WB13R AgNPs resulted in maximum inhibition of most fungi. Results also showed that the most significant inhibition of plant pathogenic fungi was observed on PDA and 100 ppm of AgNPs.

• Mycobiology
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• 제40권1호
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• pp.14-19
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• 2012

A $Mariannaea$ fungus was isolated during investigation of an elm tree infested with unidentified beetles. Based on morphological characteristics and molecular analysis of the internal transcribed spacer rDNA sequence, the fungus was identified as $Mariannaea$ $elegans$ var. $elegans$. Fungal growth was better on malt extract agar than on potato dextrose agar and oatmeal agar. Optimal temperature and pH for growth of the fungus were $30^{\circ}C$ and pH 7.0, respectively. The fungus was found to have the ability to produce extracellular enzymes such as amylase, ${\beta}$-glucosidase, cellulase, and protease. This is first report on $M.$ $elegans$ var. $elegans$ in Korea.