• The Korean Journal of Mycology
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• v.44 no.1
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• pp.16-22
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• 2016

Five islands (Sinjindo, Mado, Daenanjido, Wonsando, and Sapsido) and the coastal area (Muchangpo) in Chungnam, Korea, were selected to determine the diversity of arbuscular mycorrhizal (AM) fungi. Soil-inhabiting AM fungi were isolated and identified on the basis of morphological characteristics and sequence analyses of 18s rDNA. The differences in the fungal community structures were compared among sites. As a result, 24 species of AM fungi were identified, of which two species of AM fungi, Acaulospora brasiliensis and Redeckera fulvum, were isolated for the first time in Korea. This study revealed that AM fungal spore abundance was low and the genus Acaulospora was dominant in most of the islands. AM fungal community structures in five Islands were highly similar. However, the coastal area, Muchangpo, had different AM fungal community structure from the islands.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.345-351
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• 2018

A fungal isolate denoted NC14-264 was isolated from the soil in Jeongeup, Jeollabuk-do, Korea. Species in genus Plectosphaerella are pathogenic to several plant species, leading to fruit, root, and collar rot and collapse. In this study, a strain NC14-264 belonging to the Plectosphaerella was isolated from the soil and identified. Colonies were moderately grown, reaching 54 mm in diameter on potato dextrose agar, 49 mm on malt extract agar, and 55 mm on oatmeal agar at $25^{\circ}C$ after 10 days of incubation. Most Plectosphaerella species are distinguishable morphologically by irregular chlamydospores and different proportions of phialides and conidia. Based on morphological features and phylogenetic analysis using the internal transcribed spacer region and partial 28S rRNA gene sequences, the isolated fungus was identified as Plectosphaerella sinensis belonging to the Plectosphaerellaceae. This is the first report of P. sinensis in Korea.

• Mycobiology
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• v.51 no.2
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• pp.79-86
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• 2023

In this study, fungal strains designated as KNUF-22-14A and KNUF-22-15A were isolated from soil samples in Korea. These two strains were identified based on cultural and morphological characteristics as well as phylogenetic analyses and were found to be morphologically and phylogenetically identical. Upon their morphological comparison with closely related species, such as Tolypocladium album, T. amazonense, T. endophyticum, T. pustulatum, and T. tropicale, a difference in the size of short phialides [0.6-2.4(-9.3)×0.8-1.4 ㎛] was observed. Meanwhile, these strains had larger conidia (1.2-3.0×1.2-3.0 ㎛) than T. album, T. amazonense, T. endophyticum, and T. tropicale and smaller conidia than T. pustulatum. Phylogenetic analyses using a multi-locus datasets based on ITS, LSU, and SSU showed that KNUF-22-14A and KNUF-22-15A formed a distinct cluster from previously identified Tolypocladium species. Thus, these fungal strains isolated from soil in Korea are proposed as a novel species according to their characteristics and are named Tolypocladium globosum sp. nov.

• The Korean Journal of Mycology
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• v.47 no.1
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• pp.29-34
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• 2019

A fungal isolate designated 17E029 was isolated from a soil sample in Jeju, Korea. The strain was similar to other Allantophomopsiella species in its morphological characteristics such as grey mycelia, conidiophore, and conidia sizes. The isolate produced aerial mycelia, which appeared grey on the reverse side of the media surfaces and turned black on the front side of the colonies. The conidiophores emanating from the hyphae were hyaline, grey, aseptate, branched, and $6.7{\sim}9.2{\times}1.8{\sim}2.5{\mu}m$. Conidiogenous cells were ovoid to subcylindrical, discrete, guttulate, and hyaline. Conidia were hyaline, aseptate, smooth, guttulate, oval to subcylindrical, irregular in shape, and $6.0{\sim}7.8{\times}3.0{\sim}3.4{\mu}m$. The strain was confirmed based on phylogenetic analysis of the closest related organism, A. pseudotsugae CBS 288.37, using the partial 28S, internal transcribed spacer rDNA regions, and partial RNA polymerase II second largest subunit locus (RPB2) gene sequences along with its culture characteristics. Therefore, morphological observations and phylogenetic analysis revealed that strain 17E029 is similar to the previously identified A. pseudotsugae. Hence, this species was described as A. pseudotsugae strain 17E029, which is a new record in Korea.

• The Korean Journal of Mycology
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• v.51 no.2
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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.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.391-402
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• 2021

Earthworms play an important role in soil fertilization, interacting continually with microorganisms. This study aims to demonstrate the existence of beneficial microorganisms living in the earthworm's immune system, the coelomic fluid. To achieve this goal, a molecular identification technique was performed, using cytochrome c oxidase I (COI) barcoding to identify abundant endogenic earthworms inhabiting the temperate zone of Rabat, Morocco. Then, 16S rDNA and ITS sequencing techniques were adopted for bacteria and fungi, respectively. Biochemical analysis, showed the ability of bacteria to produce characteristic enzymes and utilize substrates. Qualitative screening of plant growth-promoting traits, including nitrogen fixation, phosphate and potassium solubilization, and indole acetic acid (IAA) production, was also performed. The result of mitochondrial COI barcoding allowed the identification of the earthworm species Aporrectodea molleri. Phenotypic and genotypic studies of the sixteen isolated bacteria and the two isolated fungi showed that they belong to the Pseudomonas, Aeromonas, Bacillus, Buttiauxella, Enterobacter, Pantoea, and Raoultella, and the Penicillium genera, respectively. Most of the isolated bacteria in the coelomic fluid showed the ability to produce β-glucosidase, β-glucosaminidase, Glutamyl-β-naphthylamidase, and aminopeptidase enzymes, utilizing substrates like aliphatic thiol, sorbitol, and fatty acid ester. Furthermore, three bacteria were able to fix nitrogen, solubilize phosphate and potassium, and produce IAA. This initial study demonstrated that despite the immune property of earthworms' coelomic fluid, it harbors beneficial microorganisms. Thus, the presence of resistant microorganisms in the earthworm's immune system highlights a possible selection process at the coelomic fluid level.

• Mycobiology
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• v.48 no.6
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• pp.450-463
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• 2020

The strains 17E-042, 17E-039, and NC13-171 belong to Ascomycota and were isolated from soil collected from Sancheong-gun and Yeongam-gun, Korea. The strain 17E-042 produced white mycelial colonies that developed a sienna color with a round margin on potato dextrose agar (PDA), and the reverse side developed a light sienna color. Morphologically, this strain was similar to the strains of Arthrinium phragmites and A. hydei, but the shorter conidial size of the newly identified strain (17E-042) was distinct. The strain 17E-039 produced macroconidia that were pale yellow to orange-brown, elongated-ellipsoid to oblong, round at both ends, primarily straight but sometimes slightly curved, 0-septate, thin-walled, and filled with numerous droplets, having diameters of 20.4-34.3 × 8.0-12.0 ㎛. And the strain NC13-171 formed hyaline to light brown chlamydospores, solitary or in a chain. Multigene phylogenetic analyses were conducted using sequence data obtained from internal transcribed spacer (ITS) regions, 28S rDNA large subunit (LSU), β-tubulin (TUB2), translation elongation factor 1-alpha (TEF1-α), and RNA polymerase II large subunit (RPB2) genes. The results of molecular phylogeny, the detailed descriptions and illustrations of each species strongly support our proposal that these strains from soil in Korea be designated as Arthrinium minutisporum sp. nov. and two new records of Pezicula neosporulosa and Acrocalymma pterocarpi.

• Journal of Ecology and Environment
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• v.41 no.9
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• pp.271-280
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• 2017

Background: Soil microorganisms play key roles in nutrient cycling and are distributed throughout the soil profile. Currently, there is little information about the characteristics of the microbial communities along the soil depth because most studies focus on microorganisms inhabiting the soil surface. To better understand the functions and composition of microbial communities and the biogeochemical factors that shape them at different soil depths, we analyzed microbial activities and bacterial and fungal community composition in soils up to a 120 cm depth at a fallow field located in central Korea. To examine the vertical difference of microbial activities and community composition, ${\beta}$-1,4-glucosidase, cellobiohydrolase, ${\beta}$-1,4-xylosidase, ${\beta}$-1,4-N-acetylglucosaminidase, and acid phosphatase activities were analyzed and barcoded pyrosequencing of 16S rRNA genes (bacteria) and internal transcribed spacer region (fungi) was conducted. Results: The activity of all the soil enzymes analyzed, along with soil C concentration, declined with soil depth. For example, acid phosphatase activity was $125.9({\pm}5.7({\pm}1SE))$, $30.9({\pm}0.9)$, $15.7({\pm}0.6)$, $6.7({\pm}0.9)$, and $3.3({\pm}0.3)nmol\;g^{-1}\;h^{-1}$ at 0-15, 15-30, 30-60, 60-90, and 90-120 cm soil depths, respectively. Among the bacterial groups, the abundance of Proteobacteria (38.5, 23.2, 23.3, 26.1, and 17.5% at 0-15, 15-30, 30-60, 60-90, and 90-120 cm soil depths, respectively) and Firmicutes (12.8, 11.3, 8.6, 4.3, and 0.4% at 0-15, 15-30, 30-60, 60-90, and 90-120 cm soil depths, respectively) decreased with soil depth. On the other hand, the abundance of Ascomycota (51.2, 48.6, 65.7, 46.1, and 45.7% at 15, 30, 60, 90, and 120 cm depths, respectively), a dominant fungal group at this site, showed no clear trend along the soil profile. Conclusions: Our results show that soil C availability can determine soil enzyme activity at different soil depths and that bacterial communities have a clear trend along the soil depth at this study site. These metagenomics studies, along with other studies on microbial functions, are expected to enhance our understanding on the complexity of soil microbial communities and their relationship with biogeochemical factors.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1347-1356
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• 2013

Tricholoma matsutake, an ectomycorrhiza that has mutual relationships with the rootlet of Pinus denisflora, forms a fruiting body that serves as a valuable food in Asia. However, the artificial culture of this fungus has not been successful. Soil fungi, including T. matsutake, coexist with many other microorganisms and plants; therefore, complex microbial communities have an influence on the fruiting body formation of T. matsutake. Here, we report on the structures of fungal communities associated with the fairy ring of T. matsutake through the pyrosequencing method. Soil samples were collected inside the fairy ring zone, in the fairy ring zone, and outside the fairy ring zone. A total of 37,125 sequencing reads were obtained and 728 to 1,962 operational taxonomic units (OTUs) were observed in the sampling zones. The fairy ring zone had the lowest OTUs and the lowest fungal diversity of all sampling zones. The number of OTUs and fungal taxa inside and outside the fairy ring zone was, respectively, about 2 times and 1.5 times higher than the fairy ring. Taxonomic analysis showed that each sampling zone has different fungal communities. In particular, out of 209 genera total, 6 genera in the fairy ring zone, such as Hemimycena, were uniquely present and 31 genera, such as Mycena, Boletopsis, and Repetophragma, were specifically absent. The results of metagenomic analysis based on the pyrosequencing indicate a decrease of fungal communities in the fairy ring zone and changes of fungal communities depending on the fairy ring growth of T. matsutake.