• Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.259-263
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• 2012

To isolate an alginate-degrading bacterium, we conducted a single colony isolation using a solid medium containing alginate as the sole carbon source. A marine bacterium Y-4 capable of degrading alginate was isolated from seawater. The strain was identified to be Pseudoalteromonas sp., based on morphological, biochemical, 16S rDNA homology, and phylogenetic analyses. Moreover, Pseudoalteromonas sp. Y-4 exhibited alginate lyase activity in the presence of 4% alginate even though many known alginate-degrading bacteria degrade in the range of 0.5-1% alginate. The optimum culture conditions for the Y-4 strain were 2% alginate, pH 8.0, and 3% NaCl at $30^{\circ}C$. The highest alginate lyase activity was also observed under the same conditions. To our knowledge, this is the first reported isolation of a marine bacterium degrading high concentrations of alginate.

• Korean Journal of Plant Taxonomy
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• v.49 no.4
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• pp.294-299
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• 2019

Allium ulleungense (subg. Anguinum, Amaryllidaceae), from Ulleungdo Island, Korea, is described as a new species. It is clearly distinguished from its close relatives, A. microdictyon and A. ochotense, by its broader leaves and larger whitish perianth and by its diploid chromosome number, which is 2n = 2x = 16. The lengths of the chromosomes range from 11.3 to 15.75 ㎛. Molecular phylogenetic analyses using nuclear and chloroplast markers also clearly indicate that A. ulleungense is genetically distinct from other species of the subg. Anguinum.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.135-149
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• 2020

Da-Lat is a hilly area located in southern Vietnam. Macrofungal diversity of Da-Lat was investigated from 2018 to 2019. A total of 468 macrofungal specimens was collected and identified using the modern species concept and taxonomic and phylogenetic analyses. Among them, internal transcribed spacer(ITS) region of 401 specimens were successfully sequenced and compared with those of related species retrieved from GenBank. In total, 180 specimens were identified at the species level. The sequenced specimens were classified into 2 phyla, 13 orders, 38 families, 93 genera, and 124 species. The remaining 221 specimens (175 species) did not match the species level. This study is the first well-documented taxonomic list of macrofungi collected from southern Vietnam.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.197-207
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• 2020

In the screening of fungal diversity, two strains were collected from the soil of Yeongcheon and dissected guts from the bodies of Chinese rice grasshopper (Oxya chinensis), Chinese grasshopper (Acrida cinerea), and Far eastern devil grasshopper (Oedaleus infernalis) from Daejeon in Korea. They were identified as Umbelopsis vinacea (KNU-YC-1801B) and Mucor hiemalis f. corticola (KNU-20F7, KNU-20F8, KNU-20F9). Multigene phylogenetic analyses of the internal transcribed spacer (ITS) regions, and large subunit (LSU) sequence data confirmed two unreported taxa along with their morphology. The results of molecular phylogeny firmly supported the detailed description and illustration for each taxon. As far as we know, both Umbelopsis vinacea and Mucor hiemalis f. corticola are the first reported taxa in Korea.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.77-80
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• 2000

Various analytical methods such as electron microscopy, quinone analysis, and 16S rDNA sequencing studies were used to investigate the microbial communities and to identify the microorganisms responsible for enhanced biological phosphorus removal (EBPR) in an anaerobic/aerobic sequencing batch reactor (SBR) fed with acetate. Electron photomicrographs showed that oval-shaped microorganisms of about $0.7\;{\sim}\;1\;{\mu}m$ in diameter dominated the microbial sludge. These microorganisms contained polyphosphate granules and glycogen inclusions, which suggests that they are a kind of phosphorus accumulating organism. Quinone and 16S rRNA sequence analyses showed that the members of Proteobacteria beta subclass were the most abundant species, which were affiliated with the Rhodocyclus-likes group. Phylogenetic analysis revealed that the two dominating clones of the beta subclass were most distantly related to Propionivibrio dicarboxylicus DSM 5885 and Rhodocyclus tenuis DSM 109 with about 95% and 96% sequence similarity, respectively. Therefore, it was concluded that the oval-shaped organisms related to the Rhodocyclus-likes group are likely to be responsible for biological phosphorus removal in SBR operation supplied with acetate.

• ALGAE
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• v.35 no.1
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• pp.33-43
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• 2020

Two species of the agar-yielding genus Gelidium, G. galapagense and G. isabelae, have previously been reported from Korea but their occurrence has not been confirmed with molecular data. We intensively collected samples of Gelidium from Jeju Island, where the two species were reported, and the southern coast of Korea. Phylogenetic analyses based on cox1 and rbcL sequences revealed that only a single species occurred in Korea. The Korean species was distantly related to G. galapagense and G. isabelae from the Galápagos Islands, and formed a clade with G. microdonticum, G. millarianum, and G. pakistanicum. A new species, G. palmatum, is described for those specimens that were previously recognized as either G. galapagense or G. isabelae from Korea. G. palmatum is small in size (up to 0.7 cm), with compressed, lanceolate axes, irregular, digitate to palmate branches, abundant rhizines in the medulla, tetrasporangial sori without sterile margins, and rounded bilocular cystocarps borne subapically on palmate branchlets.

• Mycobiology
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• v.47 no.3
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• pp.261-272
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• 2019

Oomycetes are widely distributed in various environments, including desert and polar regions. Depending upon different habits and hosts, they have evolved with both saprophytic and pathogenic nutritional modes. Freshwater ecosystem is one of the most important habitats for members of oomycetes. Most studies on oomycete diversity, however, have been biased mostly towards terrestrial phytopathogenic species, rather than aquatic species, although their roles as saprophytes and parasites are essential for freshwater ecosystems. In this study, we isolated oomycete strains from soil sediment, algae, and decaying plant debris in freshwater streams of Korea. The strains were identified based on cultural and morphological characteristics, as well as molecular phylogenetic analyses of ITS rDNA, cox1, and cox2 mtDNA sequences. As a result, we discovered eight oomycete species previously unknown in Korea, namely Phytopythium chamaehyphon, Phytopythium litorale, Phytopythium vexans, Pythium diclinum, Pythium heterothallicum, Pythium inflatum, Pythium intermedium, and Pythium oopapillum. Diversity and ecology of freshwater oomycetes in Korea are poorly understood. This study could contribute to understand their distribution and ecological function in freshwater ecosystem.

• Mycobiology
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• v.49 no.5
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• pp.476-490
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• 2021

Global temperatures are steadily increasing, leading to significant changes in microbial diversity and ecology. In the present study, we isolated high-temperature-growing fungi and fungi-like group (Oomycota) strains from freshwater environments of Korea and identified them based on cultural, morphological, and multilocus phylogenetic analyses. As a result, we introduce Saksenaea (Fungi) isolates as a new species, Saksenaea longicolla sp. nov. and record Phytophthora chlamydospora and P. lagoariana (Oomycota) new to Korea. In the growth experiments, they exhibited high-temperature tolerance, which can grow at 35-40 ℃ but become inactive at 4 ℃ and below. This study confirms the presence of high-temperature-tolerant fungi and oomycetes in Korea and suggests that the Korean climate conditions are changing in favor of these species. This indicates that climate warming is altering microbial distributions in freshwater environments.

• The Korean Journal of Mycology
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• v.49 no.2
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• pp.183-197
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• 2021

Various freshwater ecosystems, such as streams, lakes and rivers, provide a dynamic habitat for fungi. In this study, we isolated several fungal strains from freshwater sediment and plant litter. The strains were identified using molecular phylogenetic analyses of rDNA and beta tubulin (TUB) sequences. Morphological characteristics of the fungi were also investigated using microscopy and culture characteristics of the fungi grown on several media. We identified seven species previously unrecorded in Korea, Nothophoma spiraeae, Westerdykella aquatica, W. aurantiaca, W. dispersa, Chrysosporium sanyaense, C.pseudomerdarium and Taeniolella phialosperma.

• Mycobiology
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• v.46 no.4
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• pp.311-316
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• 2018

Amylosporus sulcatus sp. nov. is described from Nonggang Nature Reserve, southern China, on the basis of morphological and molecular data. The morphological description and illustrations for the new species are provided. The species is characterized by pileate and stipitate basidiocarps. The pileus surface is obviously concentrically and radiately sulcate and tomentum, and the pore surface is snow white. Phylogenetic analyses based on sequences of the internal transcribed spacer and nuclear large subunit ribosomal DNA confirmed it to be a new species.