• 한국균학회지
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• 제48권3호
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• pp.187-195
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• 2020

Two unreported fungal isolates, KNU-GW1901 and KNU-AP100C, were collected from soil sample in Gyeongsangbuk-do, Korea. Their cultural and morphological characteristics were examined after 4 weeks of incubation at 25℃ on potato dextrose agar (PDA), malt extract agar (MEA), and oatmeal agar (OA). The conidial shape of KNU-GW1901 was aseptate, hyaline, globose to ellipsoidal, oblong, and reniform to pyriform and 2.61-4.97×1.93-3.61 ㎛ in size, whereas no conidial structures were observed in KNU-AP100C. The internal transcribed spacer (ITS) regions, large subunit (LSU), and small subunit (SSU) sequences were used to determine the taxonomic positions of the strains using the maximum likelihood phylogenetic tree. The isolate KNU-GW1901 was closely clustered with Plenodomus sinensis MFLUCC 17-0767, and KNU-AP100C was closely matched with P. collinsoniae CBS 120227. Based on the findings of morphological, cultural, and phylogenetic analysis, the isolates KNU-GW1901 and KNU-AP100C were identical to the previously described P. sinensis and P. collinsoniae isolates, respectively, which are first reported in Korea.

• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.334-336
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• 2014

A new species named Aspergillus cumulatus sp. nov. is described in Aspergillus section Aspergillus (Eurotium state). The type strain (KACC $47316^T$) of this species was isolated from rice straw used in meju fermentations in Korea, and other strains were isolated from the air in a meju fermentation room. The species is characterized by growth at a wide range of water activities and the formation of aerial hyphae on malt extract 60% sucrose agar (ME60S) that resemble a cumulus cloud. Furthermore, A. cumulatus produces yellow ascomata containing small lenticular ascospores (5.1-5.7 ${\mu}m$) with a wide furrow, low equatorial crests, and tuberculate convex surface. The species is phylogenetically distinct from the other reported Aspergillus section Aspergillus species based on multilocus sequence typing using rDNA-ITS, ${\beta}$-tubulin, calmodulin, and RNA polymerase II genes.

• 미생물학회지
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• 제22권2호
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• pp.103-110
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• 1984

The conditions for the protoplast fusion of auxotrophic mutants of Trichoderma koningii were determined. A preparation of commercial enzyme Driselase was used successfully to isolate protoplasts from the 18 hr old mycelium of T. koningii. The yields of protoplasts production were ranged from $0.3{\times}10^8$ to $2.5{\times}10^8$ protoplasts per mg of damp mycelium of various auxotrophic mutant strains. The regeneration frequencies from $9.3{\times}10^{-3}\;to\;2.0{\times}10^{-1}$ were obtained when the protoplasts from auxotrophic mutants were plated on the malt extract medium containing 0.6M $MgSO_4$, and 2% agar, and the optimal concentration of PEG for protoplst fusion was 30%. Exposure of protoplasts to PEG for 10 min was found to be sufficient to induce high frequency heterokaryon formation. Optimal pH of fusion mixture was determined as 5.5, and 1 mM of calcium chloride in fusion mixture was found to be sufficient to enhance protoplast fusion frequency. Under optimal condition, the fusion frequency of the cross between protoplasts from various auxotrophic mutants were $1.6{\times}10^{-2}\;and\;4.1{\times}10^{-2}$.

• Mycobiology
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• 제51권2호
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• pp.72-78
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• 2023

In this study, a fungal strain KNUF-22-025 belonging to the genus Botryotrichum was isolated from the soil in Korea. The cultural and morphological characteristics of this strain differed from those of closely related species. On malt extract agar, strain KNUF-22-025 showed slower growth than most of the related species, except B. domesticum. The conidia size (9.6-21.1×9.9-18.4 ㎛) of strain KNUF-22-025 was larger than those of B. piluliferum, B. domesticum, and B. peruvianum but smaller than those of B. atrogriseum and B. iranicum. Conidiophores in strain KNUF-22-025 (137 ㎛) were longer than those in other closely related species but shorter than those in B. atrogriseum. Multi-locus analysis of molecular markers, such as ITS, 28S ribosomal DNA, RBP2, and TUB2 revealed that strain KNUF-22-025 was distinct from other Botryotrichum species. Thus, this strain is proposed as a novel species based on morphological characteristics along with molecular phylogeny and named Botryotrichum luteum sp. nov.

• 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.

• 한국균학회지
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• 제50권3호
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• pp.195-204
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• 2022

A fungal strain, designated KNUF-20-NI009, was isolated from soil collected from Gunsan-si, Jeollabuk-do, Korea. The isolate showed cultural features typical of the genus Xenoroussoella. Colonies cultivated on malt extract agar were olivaceous-brown to pale olivaceous-white at the margins, with undersides of dark olivaceous to olivaceous-brown and a white margin. The conidia, with a size range of 2.7-5.1×1.6-3.3 ㎛ ($\bar{x}=3.6\times2.6{\mu}m$, n=50), were globoid to ellipsoid in shape, hyaline when immature, becoming light brown to golden-brown when mature, and characterized by 1 or 2 guttules. Multi-locus sequence analysis based on a combined dataset of internal transcribed spacer regions (ITS), large subunit rDNA (LSU), small subunit rDNA (SSU), translation elongation factor 1-alpha (TEF1α), and RNA polymerase II largest subunit (RPB2) sequences revealed KNUF-20-NI009 to be a strain of Xenoroussoella triseptata. This is the first report of this species in Korea.

• 한국균학회지
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• 제51권4호
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• pp.491-504
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• 2023

To explore fungal diversity in orchard soil where fire-blighted apple trees are buried, we collected soil samples from apple orchards in Chungju, Korea. Fungal isolates were obtained from DG18 agar and identified at the species level based on morphological features and phylogenetic analyses. The colony characteristics and microstructures were examined using a light microscope and a scanning electron microscope after culturing on potato dextrose agar (PDA), malt extract agar (MEA), Czapek yeast agar (CYA), and oatmeal agar (OA) The PCR-amplified products of the ITS1-5.8S-ITS2 region and 28S large subunit of the nuclear ribosomal RNA gene, as well as partial sequences of the β-tubulin, calmodulin, and translation elongation factor 1-α genes were sequenced and analyzed phylogenetically. Seven previously unknown fungal species were explored in Korea. All samples, including Aspergillus aureolatus, Botryotrichum atrogriseum, Dactylonectria novozelandica, Fusarium denticulatum, Paecilomyces tabacinus, Sarcopodium tibetense and Talaromyces stollii, had ascomycetes. Herein, we report their descriptions and features.

• KSBB Journal
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• 제23권3호
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• pp.219-225
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• 2008

본 연구는 국외토양으로부터 분리한 400여개의 군주에서 agar plug assay를 이용하여 식물병원균에 대한 항진균성물질을 생산하는 방선균 (I-8)을 분리하였다. 항진균 물질 생산의 최적 조건을 검토한 결과 공시균 I-8은 pH 8로 조정된 ISP No. 2 배지에서 항진균물질 생산성이 가장 우수한 것으로 입증되었다. 공시균 I-8의 식물병원균의 생육저해 기구를 규명하기 위한 기초 연구로서 공시균 I-8이 세포벽 구성성분인 cellulase, chitinase와 같은 가수분해효소를 생산하는 것을 확인하였다. I-8의 배양액은 ethyl acetate추출물에서 식물병원균 14개 균주에 항진균 활성을 나타내었고 ethyl ether추출액에서는 식물병원균 10개 균주에 항진균 활성을 나타내었다. I-8의 ethyl acetate추출물은 공시균인 13-16의 추출물과 혼합사용시 식물병원균인 Monosporascus cannonballus KACC 40940에 대한 항진균력의 상승효과를 확인할 수 있었다. I-8균주 배양체는 고체배지상에서 16개의 식물병원균에 대해 강한 생육저해 효과를 보여, 광범위한 항진균 활성을 나타내는 것을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.767-772
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• 2008

Biodegradation of endocrine-disrupting phthalates [diethyl phthalate (DEP), dimethyl phthalate (DMP), butylbenzyl phthalate (BBP)] was investigated with 10 white rot fungi isolated in Korea. When the fungal mycelia were added together with 100 mg/l of phthalate into yeast extract-malt extract-glucose (YMG) medium, Pleurotus ostreatus, Irpex lacteus, Polyporus brumalis, Merulius tremellosus, Trametes versicolor, and T. versicolor MrP1 and MrP13 (transformant of the Mn-repressed peroxidase gene of T. versicolor) could remove almost all of the 3 kinds of phthalates within 12 days of incubation. When the phthalates were added to 5-day pregrown fungal cultures, most fungi except I. lacteus showed the increased removal of the phthalates compared with those of the non-pregrown cultures. In both culture conditions, p. ostreatus showed the highest degradation rates for the 3 phthalates tested. BBP was degraded with the highest rates among the 3 phthalates by all fungal strains. Only 14.9% of 100 mg/I BBP was degraded by the supernatant of P. ostreatus culture in YMG medium in 4 days of incubation, but the washed or homogenized mycelium of P. ostreatus could remove 100% of BBP within 2 days even in distilled water, indicating that the initial BBP biodegradation by P. ostreatus may be attributed to mycelium-associated enzymes rather than extracellular enzymes. The biodegradation rate of BBP by the immobilized cells of P. ostreatus was almost same as that in the suspended culture. The estrogenic activity of 100 mg/I DMP decreased during biodegradation by P. ostreatus.