61 results on '"Kwang-Yeop Jahng"'
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2. Marinobacterium boryeongense sp. nov., isolated from seawater
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Jeesun Chun, Kwang Yeop Jahng, Kyung Pyo Son, Ji Young Kang, and Mi-Jung Kim
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DNA, Bacterial ,Oceanospirillaceae ,0106 biological sciences ,0301 basic medicine ,Ubiquinone ,Biology ,010603 evolutionary biology ,01 natural sciences ,Microbiology ,03 medical and health sciences ,Marinobacterium ,RNA, Ribosomal, 16S ,Republic of Korea ,Seawater ,Gene ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Base Composition ,Oxidase test ,Phylogenetic tree ,Strain (chemistry) ,Fatty Acids ,Sequence Analysis, DNA ,General Medicine ,biology.organism_classification ,16S ribosomal RNA ,Bacterial Typing Techniques ,genomic DNA ,030104 developmental biology - Abstract
A Gram-stain-negative and strictly aerobic bacterium, designated DMHB-2T, was isolated from a sample of seawater collected off the Yellow Sea coast of the Republic of Korea. Cells were short rods and motile by means of a single polar flagellum. Catalase and oxidase activities were positive. Growth occurred at pH 5.5–10.0 (optimum, pH 6.0), 15–45 °C (optimum, 25 °C) and with 1–9 % NaCl (optimum, 3 %). The respiratory quinone was ubiquinone-8 and the major fatty acids were C16 : 0 (17.9 %), summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 26.1 %) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 37.4 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain DMHB-2T belong to the genus Marinobacterium , with the highest 16S rRNA gene sequence similarity of 95.2 % to Marinobacterium zhoushanense KCTC 42782T. The genomic DNA G+C content of strain DMHB-2T was 60.8 mol%. On the basis of the phenotypic, chemotaxonomic and genotypic characteristics presented in this study, strain DMHB-2T is suggested to represent a novel species of the genus Marinobacterium , for which the name Marinobacterium boryeongense sp. nov. is proposed. The type strain is DMHB-2T (=KACC 19225T=JCM 31902T).
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- 2019
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3. Gemmobacter straminiformis sp. nov., isolated from an artificial fountain
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Kwang Yeop Jahng, Jeesun Chun, Kyung Pyo Son, Ji Young Kang, and Mi-Jung Kim
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DNA, Bacterial ,0301 basic medicine ,Ubiquinone ,Biology ,Cell morphology ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Glycolipid ,RNA, Ribosomal, 16S ,Republic of Korea ,Rhodobacteraceae ,Phospholipids ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Phosphatidylglycerol ,Base Composition ,Oxidase test ,Phylogenetic tree ,Strain (chemistry) ,Fatty Acids ,Sequence Analysis, DNA ,General Medicine ,biology.organism_classification ,16S ribosomal RNA ,Bacterial Typing Techniques ,030104 developmental biology ,chemistry ,Biochemistry ,Water Microbiology - Abstract
A Gram-stain-negative, non-motile and facultative anaerobic bacterium, designated CAM-8T, was isolated from an artificial fountain at Chonbuk National University, South Korea. The novel strain grew at 20–37 °C (optimum 25 °C), pH 5.5–7.0 (optimum 6.0) and with 0–2 % NaCl (optimum 0 %). Oxidase and catalase activities were positive. The cell morphology of strain CAM-8T was atypical rods 0.6–0.8 µm in width and 4.5–6.5 µm in length, with a peaked tip and sometimes a bulb shape. CAM-8T existed as single cells, and as pairs or chains of cells. The phylogenetic analysis of 16S rRNA gene sequences indicated that strain CAM-8T clustered with Gemmobacter nectariphilus JCM 11959T and Gemmobacter megaterium JCM 18498T within the genus Gemmobacter . The DNA G+C content of strain CAM-8T was 65.9 mol%. The respiratory quinone was ubiquinone Q-10. The major fatty acids were C18 : 1 ω7c and/or C18 : 1 ω6c. The polar lipids of strain CAM-8T consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, two uncharacterized phospholipids, an uncharacterized aminolipid, an uncharacterized glycolipid, an uncharacterized aminophospholipid and four uncharacterized lipids. On the basis of phenotypic, phylogenetic and chemotaxonomic data, strain CAM-8T (=KACC 19224T=JCM 31905T) is considered to represent a novel species of the genus Gemmobacter , for which the name Gemmobacter straminiformis sp. nov. is proposed.
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- 2017
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4. Uliginosibacterium flavum sp. nov. isolated from an artificial lake
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Jeesun Chun, Kwang Yeop Jahng, and Ji Young Kang
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DNA, Bacterial ,0106 biological sciences ,0301 basic medicine ,Rhodocyclaceae ,Flagellum ,DNA, Ribosomal ,010603 evolutionary biology ,01 natural sciences ,Applied Microbiology and Biotechnology ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Pigment ,Cytosol ,Genus ,RNA, Ribosomal, 16S ,Botany ,Cluster Analysis ,Anaerobiosis ,Phospholipids ,Phylogeny ,Base Composition ,Facultative ,biology ,Strain (chemistry) ,Fatty Acids ,Quinones ,Betaproteobacteria ,Pigments, Biological ,Sequence Analysis, DNA ,General Medicine ,biology.organism_classification ,16S ribosomal RNA ,Bacterial Typing Techniques ,Lakes ,030104 developmental biology ,chemistry ,visual_art ,visual_art.visual_art_medium ,lipids (amino acids, peptides, and proteins) ,Locomotion ,DNA - Abstract
A Gram-negative, facultative anaerobic, rod-shaped, motile by means of a polar flagellum, greenish-yellow-pigmented bacterial strain (designated strain JJ3220T) was isolated from an artificial lake in South Korea and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain JJ3220T indicated that the isolate belongs to the family Rhodocyclaceae, and that it exhibits 96.4% similarity to Uliginosibacterium paludis KBP-13T. The major cellular fatty acids of the novel strain were C14:0, C16:0, and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). Strain JJ3220T had flexirubin-type pigments. The DNA G+C content of the strain was 62.8%. The major respiratory quinone and major polar lipid of strain JJ3220T were ubiquinone-8 and phosphatidylethanolamine, respectively. Based on the morphological and physiological properties and biochemical evidence presented, it can be concluded that strain JJ3220T represents a novel species of the genus Uliginosibacterium. The type strain Uliginosibacterium flavum is JJ3220T (=KACC 17644T =JCM 19465T).
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- 2017
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5. Viridibacterium curvum gen. nov., sp. nov., isolated from freshwater
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Kwang Yeop Jahng, Young Cheol Jung, Jeesun Chun, and Ji Young Kang
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DNA, Bacterial ,0301 basic medicine ,Rhodocyclaceae ,030106 microbiology ,Fresh Water ,Uliginosibacterium gangwonense ,Applied Microbiology and Biotechnology ,Microbiology ,03 medical and health sciences ,Genus ,RNA, Ribosomal, 16S ,Republic of Korea ,Phospholipids ,Phylogeny ,Gram ,Base Composition ,Family Rhodocyclaceae ,biology ,Strain (chemistry) ,Fatty Acids ,Sequence Analysis, DNA ,General Medicine ,16S ribosomal RNA ,biology.organism_classification ,Bacterial Typing Techniques ,030104 developmental biology ,lipids (amino acids, peptides, and proteins) ,Bacteria - Abstract
A Gram stain-negative, yellowish green-pigmented, facultatively anaerobic, motile, curved rod-shaped bacterium designated as strain JJ016T was isolated from an artificial lake in South Korea, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain JJ016T indicated that the isolate belonged to the family Rhodocyclaceae and exhibited 95.0% identity to Uliginosibacterium gangwonense 5YN10-9T. The major cellular fatty acids of the novel strain were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), C16:0, C14:0, and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The DNA G+C content of strain JJ016T was 61.9 mol%. The major respiratory quinone and major polar lipid of strain JJ016T were ubiquinone-8 and phosphatidylethanolamine, respectively. Based on the morphological and physiological properties and the biochemical evidence presented, we concluded that strain JJ016T represents a novel species of a new genus in the family Rhodocyclaceae, for which the name Viridibacterium curvum gen. nov., sp. nov. is proposed. The type strain is JJ016T (=KACC 16899T =JCM 18715T).
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- 2017
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6. A report of 42 unrecorded bacterial species belonging to the Alphaproteobacteria in Korea
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Jung-Hoon Yoon, Chang-Jun Cha, Chi-Nam Seong, Hyun Mi Jin, Jin-Woo Bae, Seung Bum Kim, Jang-Cheon Cho, Wan-Taek Im, Kiseong Joh, Kwang-Yeop Jahng, and Che Ok Jeon
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0106 biological sciences ,0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Ecology ,Alphaproteobacteria ,Biology ,16S ribosomal RNA ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences - Published
- 2016
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7. A report of 10 unrecorded bacterial species of Korea, belonging to the phylum Firmicutes
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Eunji Kim, Sungmi Choi, Jin-Woo Bae, Chang-Jun Cha, Wan-Taek Im, Kwang-Yeop Jahng, Ki-seong Joh, and Hana Yi
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0106 biological sciences ,0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,010603 evolutionary biology ,01 natural sciences - Published
- 2016
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8. A report of 38 unrecorded bacterial species in Korea, belonging to the phylum Actinobacteria
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Kiseong Joh, Jang-Cheon Cho, Wan-Taek Im, Joo Won Kang, Mi-Sun Kim, Kwang-Yeop Jahng, Ji-Hee Lee, Seung Bum Kim, Jin-Woo Bae, Che Ok Jeon, Jung-Hoon Yoon, Chang-Jun Cha, and Chi-Nam Seong
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0301 basic medicine ,biology ,Phylogenetic tree ,Strain (biology) ,Isolation (microbiology) ,16S ribosomal RNA ,biology.organism_classification ,Actinobacteria ,03 medical and health sciences ,030104 developmental biology ,Botany ,Actinomycetales ,Clade ,Nomenclature - Abstract
As a subset work for the collection of indigenous prokaryotic species in Korea, 38 actinobacterial strains were isolated from various environmental samples obtained from plant root, ginseng cultivating soil, mud flat, freshwater and seawater. Each strain showed higher 16S rRNA gene sequence similarity (>99.1%) and formed a robust phylogenetic clade with closest actinobacterial species which were defined and validated with nomenclature, already. There is no official description on these 38 actinobacterial species in Korea. Consequently, unrecorded 37 species of 24 genera in the 12 families belonging to the order Actinomycetales of the phylum Actinobacteria were found in Korea. Morphological properties, basic biochemical characteristics, isolation source and strain IDs are described in the species descriptions.
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- 2016
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9. A report on 33 unrecorded bacterial species of Korea isolated in 2014, belonging to the class Gammaproteobacteria
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Kiseong Joh, Jang-Cheon Cho, Jin-Woo Bae, Chang-Jun Cha, Chi-Nam Seong, Kwang-Yeop Jahng, Seung Bum Kim, Yochan Joung, Yeonjung Lim, Wan-Taek Im, and Gi Gyun Nam
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0301 basic medicine ,03 medical and health sciences ,Class Gammaproteobacteria ,030106 microbiology ,Gammaproteobacteria ,Zoology ,Biology ,16S ribosomal RNA ,biology.organism_classification ,Microbiology - Published
- 2016
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10. A report of 31 unrecorded bacterial species in South Korea belonging to the class Gammaproteobacteria
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Kwang Yeop Jahng, Jung-Hoon Yoon, Jin-Woo Bae, Chang-Jun Cha, Che Ok Jeon, Yong-Taek Jung, Kiseong Joh, Wan-Taek Im, Seung Bum Kim, Jang-Cheon Cho, and Chi Nam Seong
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0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Class Gammaproteobacteria ,biology ,Ecology ,Gammaproteobacteria ,Prokaryote ,biology.organism_classification - Published
- 2016
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11. A report of 21 unreported bacterial species in Korea, belonging to the Betaproteobacteria
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Che Ok Jeon, Wan-Taek Im, Kwang Yeop Jahng, Jongsik Chun, Jin-Woo Bae, Jung-Hoon Yoon, Jang-Cheon Cho, Chang-Jun Cha, Pil Soo Kim, Chi Nam Seong, Seung Bum Kim, and Kiseong Joh
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Species description ,Phylogenetic tree ,biology ,Strain (biology) ,Botany ,Alphaproteobacteria ,biology.organism_classification ,Clade ,16S ribosomal RNA ,Cell morphology ,Betaproteobacteria - Abstract
As a subset study to discover indigenous prokaryotic species in Korea, a total of 29 bacterial strains assigned to the classes Alphaproteobacteria were isolated from various environmental samples collected from plant root, ginseng soil, forest soil, marsh, mud flat, freshwater and seawater. From the high 16S rRNA gene sequence similarity (>99.1%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to each independent and predefined bacterial species. There is no official report that these 29 species included in Alphaproteobacteria is have been described in Korea; therefore 14 species of 9 genera in the order Rhizobiales, 7 species of 6 genera in the order Sphingomonadales and 4 species of 2 genera in the order Caulobacterales and 3 species in the order Rhodobacterales and 1 species in the order Rhodospirillales found in Korea. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section.
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- 2016
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12. A report of 26 unrecorded bacterial species in Korea, belonging to the Bacteroidetes and Firmicutes
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Kwang Yeop Jahng, Seung Bum Kim, Che Ok Jeon, Haneul Kim, Kiseong Joh, Chi Nam Seong, Jung-Hoon Yoon, Chang-Jun Cha, and Wan-Taek Im
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0301 basic medicine ,biology ,Phylogenetic tree ,Firmicutes ,Bacteroidetes ,Zoology ,Ribosomal RNA ,biology.organism_classification ,Cell morphology ,16S ribosomal RNA ,Bacillales ,Microbiology ,Species description ,03 medical and health sciences ,030104 developmental biology - Abstract
An outcome of the study to discover indigenous prokaryotic species in Korea, a total of 26 bacterial species assigned to the classes Bacteroidetes and Firmicutes were isolated from diverse environmental samples collected from soil, tidal flat, freshwater, seawater, wetland, plant roots, and fermented foods. From the high 16S rRNA gene sequence similarity (>99.0%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to each independent and predefined bacterial species. There is no official report that these 26 species have been described in Korea; therefore 14 strains for the order Flavobacteriales and two strains for the order Cytophagales were assigned to the class Bacteroidetes, and 8 strains for the order Bacillales and 4 strains for the order Lactobacillales were assigned to the class Firmicutes are reported for new bacterial species found in Korea. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section.
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- 2016
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13. Report on 31 unrecorded bacterial species in Korea that belong to the phylum Actinobacteria
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Jung-Hye Choi, Kiseong Joh, Wan-Taek Im, Che Ok Jeon, Jongsik Chun, Seung Bum Kim, Jung-Hoon Yoon, Chang-Jun Cha, Kwang Yeop Jahng, Jin-Woo Bae, Ju-Hee Cha, Chi Nam Seong, and Jang-Cheon Cho
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Nocardiaceae ,0301 basic medicine ,Promicromonosporaceae ,Streptomycetaceae ,Dermabacteraceae ,Actinobacteriota ,Zoology ,Streptosporangiaceae ,Cellulomonadaceae ,Tsukamurellaceae ,Actinobacteria ,03 medical and health sciences ,Actinomycetales ,Dietziaceae ,Microbacteriaceae ,Intrasporangiaceae ,Taxonomy ,Bacteria ,biology ,Ecology ,Actinobacteridae ,Biodiversity ,Propionibacteriaceae ,biology.organism_classification ,030104 developmental biology ,Phylum Actinobacteria ,Actinomycetia ,Micrococcaceae - Abstract
Choi, Jung-Hye, Cha, Ju-Hee, Bae, Jin-Woo, Cho, Jang-Cheon, Chun, Jongsik, Im, Wan-Taek, Jahng, Kwang Yeop, Jeon, Che Ok, Joh, Kiseong, Kim, Seung Bum, Seong, Chi Nam, Yoon, Jung-Hoon, Cha, Chang-Jun (2016): Report on 31 unrecorded bacterial species in Korea that belong to the phylum Actinobacteria. Journal of Species Research 5 (1): 1-13, DOI: 10.12651/JSR.2016.5.1.001, URL: http://dx.doi.org/10.12651/jsr.2016.5.1.001
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- 2016
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14. Niveibacterium umoris gen. nov., sp. nov., isolated from wetland freshwater
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Kwang Yeop Jahng, Jeesun Chun, Ji Young Kang, and Young Cheol Jung
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0301 basic medicine ,Phosphatidylglycerol ,Phosphatidylethanolamine ,Strain (chemistry) ,General Medicine ,Biology ,16S ribosomal RNA ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Genus ,Botany ,Niveibacterium umoris ,lipids (amino acids, peptides, and proteins) ,Gene ,Ecology, Evolution, Behavior and Systematics ,DNA - Abstract
A taxonomic study was carried out on a novel bacterial strain, designated MIC2059T, which was isolated from Ungok Wetland of Gochang in Korea. Cells of the isolate were found to be Gram-stain-negative, rod-shaped and motile. Comparison of the 16S rRNA gene sequences indicated that the isolate belonged to the family Rhodocyclaceae, with Uliginosibacterium gangwonense as its closest relative, with a similarity of 94.8 %. It contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) and C12 : 0 3-OH as the major fatty acids and Q8 as the respiratory ubiquinone. The polar lipid profile of strain MIC2059T revealed the presence of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as major polar lipids. In addition, phosphatidylserine, an unidentified aminophospholipid and unidentified lipids were present in small amounts. The DNA G+C content of the strain was 65.1 mol%. On the basis of the evidence presented, it is concluded that strain MIC2059T represents a novel species of a novel genus within the family Rhodocyclaceae, for which the name Niveibacterium umoris gen. nov., sp. nov. is proposed. The type strain is MIC2059T ( = KACC 17062T = JCM 18716T).
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- 2016
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15. A report of 39 unrecorded bacterial species in Korea, belonging to the Betaproteobacteria and Gammaproteobacteria
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Che Ok Jeon, Jang-Cheon Cho, Jung-Hoon Yoon, Chang-Jun Cha, Ahyoung Choi, Kiseong Joh, Kwang Yeop Jahng, Chi Nam Seong, Jin-Woo Bae, Seung Bum Kim, Wan-Taek Im, and Jongsik Chun
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Species description ,biology ,Phylogenetic tree ,Botany ,Gammaproteobacteria ,biology.organism_classification ,16S ribosomal RNA ,Clade ,Cell morphology ,Betaproteobacteria ,Aeromonadales - Abstract
As a subset study to discover indigenous prokaryotic species in Korea, a total of 39 bacterial strains assigned to the classes Betaproteobacteria and Gammaproteobacteria were isolated from diverse environmental samples collected from soil, tidal flat, freshwater, seawater, seaweed, wetland, plant roots, guts of insects, and fermented foods. From the high 16S rRNA gene sequence similarity (>99.1%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to each independent and predefined bacterial species. There is no official report that these 39 species have been described in Korea; therefore 4 species of 4 genera in the order Burkholderiales and 1 species in the order Neisseriales within the class Betaproteobacteria, and 10 species of 6 genera in the order Alteromonadales, 11 species of 3 genera in the order Pseudomonadales, 4 species of 4 genera in the order Enterobacteriales, 2 species of 2 genera in the order Vibrionales, 1 species in the order Aeromonadales, 3 species of 3 genera in the order Oceanospirillales, 2 species of 2 genera in the order Xanthomonadales, and 1 species in the order Chromatiales within the Gammaproteobacteia are reported for proteobacterial species found in Korea. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section.
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- 2015
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16. Report on 14 unrecorded bacterial species in Korea that belong to the phyla Bacteroidetes and Deinococcus-Thermus
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Kiseong Joh, Jang-Cheon Cho, Jeesun Chun, Kwang Yeop Jahng, Jung-Hoon Yoon, Jin-Woo Bae, Chang-Jun Cha, Chi Nam Seong, Seung Bum Kim, Che Ok Jeon, Wan-Taek Im, and Jongsik Chun
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Maribacter ,biology ,Phylum ,Thermus ,Bacteroidetes ,Deinococcus ,biology.organism_classification ,16S ribosomal RNA ,Deinococcus-Thermus ,Flavobacterium ,Microbiology - Abstract
Summary of strains isolated belonging to the Deinococcus Thermus and Bacteroidetes and their taxonomic affiliations.phylumfamilyGenusStrain IDNIBR IDMost closely Trelated speciesSimilarity (%)Isolation sourceMediumIncubation conditions Deinococcus ThermusDeinococcaceaeDeinococcus Deinococcus DaeR4BE44NIBRBA0000113891 NIBRBA0000113903 D. aquiradiocola TDMAuv53 T D. humi MK03 T 99.3 100.0Sediment plantR2A R2A25°C, 2d 25°C, 2d BacteroidetesFlavobacteriaceaeCellulophaga Flavobacterium Flavobacterium Flavobacterium Gramella Hyunsoonleella Lutimonas Maribacter Nonlabens Zobellia Zunongwangia KA18 KYW884 PN22 HME 8473 KYW842 KA3 KYW573 HD33 WSWMO1WSWMO2 IMCC1073NIBRBA0000114107 NIBRBA0000114126 NIBRBA0000113873 NIBRBA0000114090 NIBRBA0000114112 NIBRBA0000114106 NIBRBA0000114109 NIBRBA0000113990 NIBRBA0000114006 NIBRBA0000114007 NIBRBA0000113913 C. fucicola NN015840 F. ahnfeltiae 10Alg 130 T F. compostarboris 15C3 F. limicola ST82 T G. echinicola KMM 6050 T H. jejuensis CNU004 T L. saemankumensis
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- 2015
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17. Flaviaesturariibacter amylovorans gen. nov., sp. nov., a starch-hydrolysing bacterium, isolated from estuarine water
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Ji Young Kang, Chul Ho Kim, Jeong-Woo Seo, Jeesun Chun, and Kwang Yeop Jahng
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DNA, Bacterial ,Spermidine ,Molecular Sequence Data ,Biology ,Microbiology ,chemistry.chemical_compound ,Genus ,RNA, Ribosomal, 16S ,Republic of Korea ,Gene ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Base Composition ,Strain (chemistry) ,Phylogenetic tree ,Bacteroidetes ,Pigmentation ,Phosphatidylethanolamines ,Fatty Acids ,Starch ,Vitamin K 2 ,Sequence Analysis, DNA ,General Medicine ,16S ribosomal RNA ,biology.organism_classification ,Bacterial Typing Techniques ,R2a agar ,chemistry ,Estuaries ,Water Microbiology ,Nutrient agar ,Bacteria - Abstract
A novel bacterial strain, designated GCR0105T, was isolated from a water sample of the Mangyung estuary enclosed by the Saemangeum Embankment, located in JEOLlabuk-do, South Korea. Cells of strain GCR0105T were Gram-stain-negative, non-motile and rod-shaped. Colonies of strain GCR0105T were pale yellow-pigmented on R2A agar and nutrient agar media, and were able to grow at 15–30 °C (optimum 25 °C) and pH 6.5–8.5 (optimum pH 7.5). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GCR0105T was related most closely to Flavisolibacter ginsengisoli Gsoil 643T (93.14 % similarity). The polar lipid profile of strain GCR0105T comprised phosphatidylethanolamine, two unknown aminolipids, an unknown aminophospholipid and four unknown lipids. The DNA G+C content of strain GCR0105T was 42.9 mol% and the respiratory quinone was MK-7.On the basis of phenotypic, chemotaxonomic and phylogenetic properties, strain GCR0105T represents a novel species in a new genus within the family Chitinophagaceae, for which the name Flaviaesturariibacter amylovorans gen. nov., sp. nov. is proposed. The type strain of Flaviaesturariibacter amylovorans is GCR0105T ( = KACC 16454T = JCM 17919T).
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- 2015
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18. Investigation of Naturally Occurring Fumonisin B1 and Glycated Fumonisin B1 in Korean Feedstuffs
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Kwang Yeop Jahng, Jongsung Ahn, and Hyenjong Kim
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chemistry.chemical_classification ,Fumonisin B1 ,Mass spectrometric ,Reducing sugar ,Process conditions ,chemistry.chemical_compound ,Maillard reaction ,symbols.namesake ,chemistry ,Biochemistry ,Glycation ,Fumonisin ,symbols ,General Earth and Planetary Sciences ,Food science ,Mycotoxin ,General Environmental Science - Abstract
Mycotoxins are potentially dangerous contaminants of livestock feeds. In this study, we measured the levels of fumonisin B1 and glycated fumonisin B1 in feedstuffs and then investigated the ability of the extrusion heating regimen to convert the most prevalent mycotoxin contaminant, fumonisin B1, to a less toxic glycated form. All feed samples were analyzed with fully validated methods. All measured concentrations of fumonisin B1 were below harmful thresholds, including European Union-recommended levels or US Food and Drug Administration action levels. Because fumonisin B1 was highly contaminated mycotoxin in our present investigation and fumonisin B1 has been shown to be less toxic following Maillard type reaction with reducing sugar, we examined the formation of fumonisin B1 derivatives by Maillard reaction under extrusion process conditions. We employed a variety of tandem mass spectrometric methodologies to selectively detect fumonisin B1 derivatives and to elucidate their structures partially. We found that compounds of m/z 736 were more likely artifacts or side reaction products rather than glycation products. N-(carboxymethyl) fumonisin B1 of m/z 780 and other major glycation products of m/z 794 and 810 were not detected, and only negligible amounts of methylene fumonisin B1 was found in 10 extruded feed samples. Therefore, either the tested extrusion conditions did not induce fumonisin B1 glycation or the glycation products simply could not be detected by the method employed in this study.
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- 2015
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19. Characterization of NpgA, a 4′-phosphopantetheinyl transferase of Aspergillus nidulans, and evidence of its involvement in fungal growth and formation of conidia and cleistothecia for development
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Kwang-Yeop Jahng, Keon-Sang Chae, Ha-Yeon Song, Dong-Min Han, Hyo-Jin Choi, Jung-Mi Kim, Kum-Kang So, and Dae-Hyuk Kim
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Mutant ,Saccharomyces cerevisiae ,Transferases (Other Substituted Phosphate Groups) ,Applied Microbiology and Biotechnology ,Microbiology ,Aspergillus nidulans ,Fungal Proteins ,Sexual sporulation ,Bacterial Proteins ,Cell Wall ,Gene Expression Regulation, Fungal ,Reproduction, Asexual ,Gene ,Genetics ,biology ,Pigmentation ,Wild type ,4'-phosphopantetheinyl transferase ,Sequence Analysis, DNA ,General Medicine ,Spores, Fungal ,Thionucleotides ,biology.organism_classification ,Phenotype ,Cell biology ,Adenosine Diphosphate ,Mutation - Abstract
The null pigmentation mutant (npgA1) in Aspergillus nidulans results in a phenotype with colorless organs, decreased branching growth, delayed of asexual spore development, and aberrant cell wall structure. The npgA gene was isolated from A. nidulans to investigate these pleiomorphic phenomena of npgA1 mutant. Sequencing analysis of the complementing gene indicated that it contained a 4'-phosphopantetheinyl transferase (PPTase) superfamily domain. Enzymatic assay of the PPTase, encoded by the npgA gene, was implemented in vivo and in vitro. Loss-of-function of LYS5, which encoded a PPTase in Saccharomyces cerevisiae, was functionally complemented by NpgA, and Escherichia coli-derived NpgA revealed phosphopantetheinylation activity with the elaboration of 3'5'-ADP. Deletion of the npgA gene caused perfectly a lethal phenotype and the absence of asexual/sexual sporulation and secondary metabolites such as pigments in A. nidulans. However, a cross feeding effect with A. nidulans wild type allowed recovery from deletion defects, and phased-culture filtrate from the wild type were used to verify that the npgA gene was essential for formation of metabolites needed for development as well as growth. In addition, forced expression of npgA promoted the formation of conidia and cleistothecia as well as growth. These results indicate that the npgA gene is involved in the phosphopantetheinylation required for primary biological processes such as growth, asexual/sexual development, and the synthesis of secondary metabolites in A. nidulans.
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- 2015
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20. Psychroflexus salarius sp. nov., isolated from Gomso salt pan
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Kwang Yeop Jahng, Jeesun Chun, and Ji Young Kang
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DNA, Bacterial ,Molecular Sequence Data ,Biology ,Microbiology ,RNA, Ribosomal, 16S ,Republic of Korea ,Carotenoid ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,chemistry.chemical_classification ,Base Composition ,Oxidase test ,Psychroflexus halocasei ,Strain (chemistry) ,Phosphatidylethanolamines ,Psychroflexus salarius ,Fatty Acids ,Vitamin K 2 ,Sequence Analysis, DNA ,General Medicine ,16S ribosomal RNA ,Halophile ,Bacterial Typing Techniques ,Psychroflexus ,Biochemistry ,chemistry ,Flavobacteriaceae - Abstract
A taxonomic study was carried out on a novel bacterial strain, designated MIC1008T, which was isolated from the Gomso salt pan, located in Buan County, Korea. Cells were Gram-stain-negative, aerobic, non-motile and moderately halophilic rods, 0.2–0.4 µm wide and 0.7–1.2 µm long. The optimum temperature and pH for growth were 25 °C and pH 6.5–8.5, respectively. Catalase and oxidase activities were positive. Carotenoid pigments were produced. Comparison of 16S rRNA gene sequences indicated that the isolate belonged to the genus Psychroflexus , with Psychroflexus halocasei WCC 4520T as its closest relative, with a 16S rRNA gene sequence similarity of 95.4 %. The isolate contained iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH, anteiso-C15 : 0 and iso-C15 : 0 3-OH as the major fatty acids and menaquinone MK-6 as the isoprenoid quinone. The major polar lipid profile of strain MIC1008T revealed the presence of phosphatidylethanolamine, an unidentified aminolipid and two unidentified lipids. The DNA G+C content of the isolate was 32.9 mol%. On the basis of the evidences presented, it is concluded that strain MIC1008T represents a novel species of the genus Psychroflexus within the family Flavobacteriaceae , for which the name Psychroflexus http://dx.doi.org/10.1601/nm.8182 salarius sp. nov. is proposed. The type strain is MIC1008T ( = KACC 17063T = DSM 25661T).
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- 2014
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21. Nibribacter koreensis gen. nov., sp. nov., isolated from estuarine water
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Jeesun Chun, Ji Young Kang, and Kwang Yeop Jahng
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DNA, Bacterial ,Sequence analysis ,Cytophagaceae ,Molecular Sequence Data ,Biology ,medicine.disease_cause ,Microbiology ,Glycolipid ,Phylogenetics ,RNA, Ribosomal, 16S ,Republic of Korea ,medicine ,Phospholipids ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Base Composition ,Strain (chemistry) ,Pontibacter korlensis ,Fatty Acids ,Vitamin K 2 ,Sequence Analysis, DNA ,General Medicine ,Ribosomal RNA ,16S ribosomal RNA ,biology.organism_classification ,Bacterial Typing Techniques ,Estuaries ,Water Microbiology ,Bacteria - Abstract
A Gram-reaction-negative, rod-shaped, non-motile, red-pigmented bacterium, designated strain GSR3061T, was isolated from a water sample of the Mangyung estuary enclosed by the Saemangeum Embankment in JEOLlabuk-do of South Korea, and characterized using a polyphasic approach. 16S rRNA gene sequence analysis of strain GSR3061Tindicated that the isolate belonged to the phylumBacteroidetesand exhibited similarity levels of 94.7 % toRufibacter tibetensisNRRL B-51285T, 92.4 % toAdhaeribacter terreusKACC 14257Tand 91.9 % toPontibacter korlensisKACC 15371T. Growth was observed at 15–40 °C and pH 6.5–9.5. The major cellular fatty acids of the novel strain were summed feature 4 (comprising iso-C17 : 1I and/or anteiso-C17 : 1B), iso-C15 : 0, C17 : 1ω6cand iso-C16 : 1H. Flexirubin-type pigments were absent. The DNA G+C content of strain GSR3061Twas 44.9 mol% and the major quinone was MK-7. The polar lipid profile consisted mainly of phosphatidylethanolamine; three unidentified lipids, two unknown aminolipids, two unknown phospholipids, an unknown aminophospholipid and an unknown glycolipid were also present. On the basis of the evidence presented, it is concluded that strain GSR3061Trepresents a novel species of a new genus, for which the nameNibribacter koreensisgen. nov., sp. nov. is proposed. The type strain ofNibribacter koreensisis GSR3061T( = KACC 16450T = JCM 17917T).
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- 2013
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22. Nibrella saemangeumensis gen. nov., sp. nov. and Nibrella viscosa sp. nov., novel members of the family Cytophagaceae, isolated from seawater
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Ahyoung Choi, Ji Young Kang, Kwang Yeop Jahng, Jeesun Chun, and Jang-Cheon Cho
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DNA, Bacterial ,Spermidine ,Sequence analysis ,Cytophagaceae ,Molecular Sequence Data ,Biology ,Microbiology ,Genus ,Phylogenetics ,RNA, Ribosomal, 16S ,Republic of Korea ,Botany ,Seawater ,Gene ,Phospholipids ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Base Composition ,Phylogenetic tree ,Strain (chemistry) ,Phosphatidylethanolamines ,Fatty Acids ,Vitamin K 2 ,Sequence Analysis, DNA ,General Medicine ,Ribosomal RNA ,16S ribosomal RNA ,Bacterial Typing Techniques - Abstract
Two strains, designated GCR0103T and GYR3121T, were isolated from seawater of the Saemangeum Embankment in Jeollabuk-do, Korea. The cells of the two strains were Gram-reaction-negative and non-motile, and formed multicellular filaments. The colonies of the two strains were pink-pigmented and able to grow at 15–37 °C (optimum 25 °C) on R2A and NA medium. Strains GCR0103T and GYR3121T grew at pH 6.5–10 (optimum pH 7.5) and pH 5.5–9.5 (optimum pH 7.5), and within NaCl ranges of 0–0.4 % and 0–1 %, respectively. The polar lipid profiles of the two strains contained phosphatidylethanolamine, five unknown aminolipids, an unknown phospholipid and four or five unknown lipids. The DNA G+C contents of strains GCR0103T and GYR3121T were 56.0 and 54.5 mol%, respectively. The respiratory quinone detected in both strains was MK-7. The 16S rRNA gene sequence similarity between GCR0103T and GYR3121T was 95.5 %. The 16S rRNA gene sequence similarities of the two strains to closely related reference strains were less than 89 %. Phylogenetic analysis based on 16S rRNA genes showed that GCR0103T and GYR3121T formed a distinct phyletic line in the family Cytophagaceae . On the basis of the phenotypic, chemotaxonomic and phylogenetic properties, strains GCR0103T and GYR3121T represent two novel species in a new genus within the family Cytophagaceae , for which the names Nibrella saemangeumensis gen. nov., sp. nov. and Nibrella viscosa sp. nov. are proposed. The type strain of Nibrella saemangeumensis is GCR0103T ( = KACC 16453T = JCM 17927T) and the type strain of Nibrella viscosa is GYR3121T ( = KACC 16447T = JCM 17925T).
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- 2013
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23. Hymenobacter koreensis sp. nov. and Hymenobacter saemangeumensis sp. nov., isolated from estuarine water
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Jang-Cheon Cho, Ji Young Kang, Jeesun Chun, Sung-Hyun Moon, Kwang Yeop Jahng, and Ahyoung Choi
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DNA, Bacterial ,food.ingredient ,Spermidine ,Cytophagaceae ,Molecular Sequence Data ,Biology ,medicine.disease_cause ,Microbiology ,food ,RNA, Ribosomal, 16S ,Hymenobacter ,Republic of Korea ,Hymenobacter saemangeumensis ,medicine ,Seawater ,Genus Hymenobacter ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Base Composition ,geography ,geography.geographical_feature_category ,Strain (chemistry) ,Phosphatidylethanolamines ,Fatty Acids ,Vitamin K 2 ,Estuary ,Sequence Analysis, DNA ,General Medicine ,16S ribosomal RNA ,Water sample ,Bacterial Typing Techniques ,Hymenobacter koreensis ,Estuaries - Abstract
Two Gram-reaction-negative, rod-shaped, non-motile and red–pink-pigmented bacterial strains, designated GYR3077T and GSR0100T, were isolated from a water sample of the Mangyung estuary enclosed by the Saemangeum Embankment in JEOLlabuk-do, South Korea, and were characterized using a polyphasic approach. 16S rRNA genes of strains GYR3077T and GSR0100T exhibited sequence similarities of 95.9 % to Hymenobacter deserti ZLB-3T and 96.6 % to Hymenobacter soli PB17T, respectively, and indicated that these isolates belonged to the phylum Bacteroidetes . The major cellular fatty acids present in the two isolates were iso-C15 : 0, C16 : 1ω5c, summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B) and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The major respiratory quinone and polyamine patterns were menaquinone-7 and sym-homospermidine, characteristic of the genus Hymenobacter . Flexirubin-type pigments were absent in both strains. The DNA G+C contents of strains GYR3077T and GSR0100T were 60.2 mol% and 61.9 mol%, respectively. The major polar lipid of strains GYR3077T and GSR0100T was phosphatidylethanolamine. Based on the morphological and physiological properties, strains GYR3077T and GSR0100T were considered to represent two novel species of the genus Hymenobacter , for which the names Hymenobacter koreensis sp. nov. (type strain GYR3077T = KACC 16451T = JCM 17924T) and Hymenobacter saemangeumensis sp. nov. (type strain GSR0100T = KACC 16452T = JCM 17923T) are proposed.
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- 2013
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24. The MpkB MAP kinase plays a role in autolysis and conidiation of Aspergillus nidulans
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Ji Young Kang, Jeesun Chun, Kwang Yeop Jahng, Dong-Min Han, Keon-Sang Chae, and Sang-Cheol Jun
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Mitogen-Activated Protein Kinase Kinases ,Autolysis (biology) ,Microbial Viability ,biology ,Hypha ,Saccharomyces cerevisiae ,Hyphae ,Wild type ,Conidiation ,Spores, Fungal ,Glucanase ,biology.organism_classification ,Microbiology ,Aspergillus nidulans ,Gene Expression Regulation, Fungal ,Genetics ,Gene family ,Autolysis ,Gene Deletion - Abstract
The mpkB gene of Aspergillus nidulans encodes a MAP kinase homologous to Fus3p of Saccharomyces cerevisiae which is involved in conjugation process. MpkB is required for completing the sexual development at the anastomosis and post-karyogamy stages. The mpkB deletion strain could produce conidia under the repression condition of conidiation such as sealing and even in the submerged culture concomitant with persistent brlA expression, implying that MpkB might have a role in timely regulation of brlA expression. The submerged culture of the deletion strain showed typical autolytic phenotypes including decrease in dry cell mass (DCM), disorganization of mycelial balls, and fragmentation of hyphae. The chiB, engA and pepJ genes which are encoding cell wall hydrolytic enzymes were transcribed highly in the submerged culture. Also, we observed that the enzyme activity of chitinase and glucanase in the submerged culture of mpkB deletion strain was much higher than that of wild type. The deletion of mpkB also caused a precocious germination of conidia and reduction of spore viability. The expression of the vosA gene, a member of velvet gene family, was not observed in the mpkB deletion strain. These results suggest that MpkB should have multiple roles in germination and viability of conidia, conidiation and autolysis through regulating the expression of vosA and brlA.
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- 2013
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25. Flavobacterium aciduliphilum sp. nov., isolated from freshwater, and emended description of the genus Flavobacterium
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Kwang Yeop Jahng, Jeesun Chun, and Ji Young Kang
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DNA, Bacterial ,Spermidine ,Molecular Sequence Data ,Fresh Water ,Polyenes ,Biology ,Flavobacterium ,Microbiology ,Glycolipid ,RNA, Ribosomal, 16S ,Flavobacterium cheonanense ,Republic of Korea ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Flavobacterium aciduliphilum ,chemistry.chemical_classification ,Base Composition ,Strain (chemistry) ,Fatty Acids ,Fatty acid ,Vitamin K 2 ,Sequence Analysis, DNA ,General Medicine ,16S ribosomal RNA ,C content ,Bacterial Typing Techniques ,chemistry ,Glycolipids ,Genus Flavobacterium - Abstract
A Gram-stain-negative, rod-shaped, non-motile and yellow-pigmented bacterial strain, designated strain JJ013T, was isolated from an artificial lake in Jeollabuk-do, South Korea, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain JJ013T indicated that the isolate belonged to the family Flavobacteriaceae and exhibited similarity levels of 96.6 % to the type strains of Flavobacterium cheonanense and Flavobacterium koreense and 96.5 % to the type strain of Flavobacterium chungnamense . Growth was observed at 20–30 °C and pH 5.0–7.0. The major cellular fatty acids of the novel strain were iso-C15 : 0 (27.5 %), iso-C15 : 1 G (17.8 %), iso-C17 : 0 3-OH (9.4 %) and iso-C15 : 0 3-OH (9.2 %). Flexirubin-type pigments were present. The DNA G+C content of strain JJ013T was 33.9 mol%, the major respiratory quinone was menaquinone-6 (MK-6) and the major polyamine was sym-homospermidine. The polar lipid profile of the strain JJ013T consisted of a phosphatidylethanolamine (PE), two unknown aminolipids (AL1–2), three unidentified lipid (L1–3) and an unknown glycolipid (GL). On the basis of the morphological and physiological properties and biochemical evidence presented, it is concluded that strain JJ013T represents a novel species of the genus Flavobacterium , for which the name Flavobacterium aciduliphilum sp. nov. is proposed; the type strain is JJ013T ( = KACC 16594T = JCM 18211T). Since C15 : 0, which is known as a predominant fatty acid of the genus Flavobacterium was not detected in the novel strain and other reference strains, we propose an emended description of the genus Flavobacterium .
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- 2013
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26. Flavobacterium fontis sp. nov., isolated from freshwater
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Kwang Yeop Jahng, Ji Young Kang, and Jeesun Chun
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DNA, Bacterial ,Spermidine ,Sequence analysis ,Molecular Sequence Data ,Fresh Water ,Biology ,Flavobacterium ,Microbiology ,Bacterial genetics ,Glycolipid ,Phylogenetics ,RNA, Ribosomal, 16S ,Republic of Korea ,Gene ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Base Composition ,Strain (chemistry) ,Fatty Acids ,Vitamin K 2 ,Sequence Analysis, DNA ,General Medicine ,Ribosomal RNA ,16S ribosomal RNA ,Bacterial Typing Techniques - Abstract
A taxonomic study was carried out on a novel bacterial strain, designated MIC3010T, which was isolated from a freshwater pond in Jeonju, Republic of Korea. Cells of the isolate were Gram-stain-negative, rod-shaped and non-motile. Comparison of the 16S rRNA gene sequences indicated that the isolate belonged to the family Flavobacteriaceae , with Flavobacterium haoranii LQY-7T as its closest relative, with a similarity of 94.2 %. The predominant fatty acids of strain MIC3010T were iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipid profile of strain MIC3010T revealed the presence of phosphatidylethanolamine (PE) and one unidentified lipid (L1) as major components. In addition, two aminolipids (AL1, AL2) and one glycolipid were present in small amounts. The DNA G+C content of the strain was 41.0 mol%. The strain contained MK-6 as the major quinone and sym-homospermidine as the predominant polyamine. On the basis of the evidence presented, it is concluded that strain MIC3010T represents a novel species of the genus Flavobacterium , for which the name Flavobacterium fontis sp. nov. is proposed. The type strain is MIC3010T ( = KACC 16593T = JCM 18212T).
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- 2013
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27. Occurrence and biotransformation of ochratoxin a during pepper sauce fermentation
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Han Sub Jang, Young Jin Song, Kwang Yeop Jahng, Jong Sung Ahn, and Tae Ho Yang
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Ochratoxin A ,Microorganism ,fungi ,Organic Chemistry ,Food spoilage ,food and beverages ,Biology ,biology.organism_classification ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Starter ,chemistry ,Biotransformation ,Aspergillus oryzae ,Pepper ,Fermentation ,Food science - Abstract
Gochujang, a savory and pungent fermented sauce, is a Korean ethnic food composed primarily of fermented soybean cake, red pepper powder, glutinous rice, and salt. Industrial gochujang is fermented following inoculation with Aspergillus oryzae and Bacillus subtilis as starter microorganisms. In contrast, a wide variety of natural fungi and bacteria are used in fermentation and aging of artisanal gochujang, the aging period of which is longer than 6 months. We monitored ochratoxin A (OTA) contamination of red pepper and gochujang available in the Korean retail market and explored the possibility that microorganisms in gochujang might degrade OTA present in contaminated red pepper during soybean fermentation and aging. We report here that OTA can be easily biotransformed serially to several products by B. Subtilis (KTCT 1021) under the conditions of our experiments. The dynamic microbial activity in gochujang might contribute to the low occurrence of ochratoxin A in this product despite the use of highly contaminated pepper powder, one of the main ingredients of gochujang. At the same time, however, an inappropriate fermentation process and the long aging period are assumed to be sources of contamination. Studies to identify critical control points and to prevent fungal spoilage by the development of high quality starters should be followed up to enable the artisan to produce OTAfree gochujang.
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- 2011
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28. The MpkB MAP kinase plays a role in post-karyogamy processes as well as in hyphal anastomosis during sexual development in Aspergillus nidulans
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Dong-Min Han, Jung-Mi Kim, Hwan-Gyu Kim, Seung-Hwan Jang, Hyun-Joo Park, Sang-Cheol Jun, Jiyoung Kang, Mi-Hee Chang, Young-Eun Leem, Sei-Jin Lee, Kwang-Yeop Jahng, Keon-Sang Chae, and Tae-Ho Yang
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Hyphal growth ,Genes, Fungal ,Molecular Sequence Data ,Mutant ,Hyphae ,Applied Microbiology and Biotechnology ,Microbiology ,Aspergillus nidulans ,Karyogamy ,Fungal Proteins ,Gene Expression Regulation, Fungal ,Cloning, Molecular ,Gene ,Heterokaryon ,Genetics ,biology ,fungi ,Wild type ,Sequence Analysis, DNA ,General Medicine ,biology.organism_classification ,Phenotype ,Meiosis ,Mitogen-Activated Protein Kinases ,Gene Deletion - Abstract
Two genes encoding MAP kinase homologs, designated as mpkB and mpkC, were isolated from Aspergillus nidulans by PCR with degenerate primers. Deletion and over-expression mutants of mpkC showed no detectable phenotypes under any external stress tested. Deletion of mpkB caused pleiotropic phenotypes including a failure in forming cleistothecia under any induction conditions for sexual development, increased Hülle cell production, slow hyphal growth and aberrant conidiophore morphology. Over-expression of mpkB led to increased cleistothecium production. While the transcripts of mpkB and mpkC were constitutively synthesized through the entire life cycle, their size and amount differed with developmental stages. An outcross test using fluorescent protein reporters showed that the mpkB deletion mutant could not form heterokaryons with wild type. Protoplast fusion experiments showed that the fusant of the mpkB mutant with wild type could undergo normal sexual development. However, heterokaryotic mycelia that were produced from a fusant between two mpkB deletion mutants could not form cleistothecia, although they did appear to form diploid nuclei. These results suggest that the MpkB MAP kinase is required for some post-karyogamy process as well as at the hyphal anastomosis stage to accomplish sexual development successfully.
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- 2011
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29. Surface modification of and selective protein attachment to a flexible microarray pattern using atmospheric plasma with a reactive gas
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Soyoung Park, Chae-Ryong Cho, Sae-Hae Choi, H. J. Lee, Kwang-Yeop Jahng, Yoon-Hee Kang, and Se-Young Jeong
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Materials science ,Biocompatibility ,Surface Properties ,Protein Array Analysis ,Biomedical Engineering ,Analytical chemistry ,Proteins ,Atmospheric-pressure plasma ,General Medicine ,Biochemistry ,Surface energy ,Sulfone ,body regions ,Biomaterials ,chemistry.chemical_compound ,Atmospheric Pressure ,chemistry ,Surface roughness ,Surface modification ,Adhesive ,human activities ,Molecular Biology ,Biotechnology ,Micropatterning - Abstract
The hydrophobic and hydrophilic properties of the surface of poly-ether sulfone (PES) films were controlled by an atmospheric pressure plasma (AP) treatment using reactive gases (Ar/H(2) and Ar/O(2)). The surface properties of the Ar/H(2) and Ar/O(2) in series AP-treated PES films showed higher surface roughness (approximately 120%), surface energy (approximately 30%) and hydrophilic properties (oxygen content approximately 10%) than the Ar/O(2) AP-treated PES film. The protein staining results confirmed that an activated region on the patterned PES film with high selectivity and sensitivity was well-defined and formed. This method is suitable for fabricating flexible protein adhesive chips with uniform biomolecular adhesive properties.
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- 2010
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30. The isolation and characterization of Pseudozyma sp. JCC 207, a novel producer of squalene
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Kwang-Yeop Jahng, Mi-Hee Chang, Seong-Chool Hong, and Hyeon-Jin Kim
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Squalene ,Microorganism ,Molecular Sequence Data ,Biology ,DNA, Ribosomal ,Applied Microbiology and Biotechnology ,Industrial Microbiology ,chemistry.chemical_compound ,DNA, Ribosomal Spacer ,Yeast extract ,Seawater ,DNA, Fungal ,Ustilaginales ,Ribosomal DNA ,Phylogeny ,Marine fungi ,Fungal genetics ,General Medicine ,Industrial microbiology ,Yeast ,Culture Media ,Biochemistry ,chemistry ,RNA, Ribosomal ,Biotechnology - Abstract
In examining the production of valuable compounds by marine microorganisms, we isolated a novel yeast strain that produces a large amount of squalene and several polyunsaturated fatty acids. Molecular and phylogenetic analyses of the ribosomal DNA suggest that the isolate belongs to the genus Pseudozyma, which comprises ustilaginomycetous anamorphic yeasts. The nucleotide sequence of an internally transcribed spacer region from isolate Pseudozyma sp. JCC207 showed 98% similarity with those of Pseudozyma rugulosa and Pseudozyma aphidis, which are close relatives of the isolate. In considering use of Pseudozyma sp. JCC207 for squalene production, the efficiency of squalene production was investigated under different conditions. Glucose was the best carbon source for the production of squalene. In the presence of yeast extract, squalene production was activated and an optimum ratio of glucose to yeast extract was 4.5. For the optimal squalene production, the concentration of glucose was 40 g l(-1) and the best nitrogen source was sodium nitrogen. Pseudozyma sp. JCC207 was shown to produce up to 5.20 g/L of biomass and 340.52 mg/L of squalene. In an optimal condition, the content and yield of squalene produced by Pseudozyma sp. JCC207 were much greater than those obtained from microorganisms previously reported as squalene producers. We identified, classified, and characterized Pseudozyma sp. JCC207 as a novel squalene producer. The squalene production rate of Pseudozyma sp. JCC207 makes it an ideal candidate for the commercialization of microbial squalene.
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- 2008
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31. Abstracts of Presentations at the 2007 Spring Meeting of the Korean Society of Mycology at the Chonnam National University, Gwangju, Korea, May 4
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Hye-Young Yu, Jeong-Ah Seo, Kap-Hoon Han, Sung-Hwan Yun, Yin-Won Lee, Kang-Hyeon Ka, Ji-Youn Chang, Sung-Ryul Ryu, Kab-Hee Yoon, Won-Chull Bak, Joon-Moh Park, Deuk-Sil Oh, Woo-Jae Cheon, Bong-Hun Lee, Yun-Hae Lee, Myoung-Jun Jang, Young-Cheol Ju, Woo-Sik Jo, Young-Hyun Rew, Sung-Guk Choi, Jae-Youl Uhm, Hoon Cho, Heung-Sun Sim, Byung-Wook Jo, Ying Wu, Cheol-Hee Choi, Woon-Seob Shin, Yu Lan Piao, Eun Jae Kim, Hye Yeon Mun, Kook Hwa Seo, Hyang Burm Lee, Heng Luo, Xinli Wei, Keon Seon Han, Young Jin Koh, Jae-Seoun Hur, Kwang-Choon Chang, In-Pyo Hong, Se-Kwon Kim, Jae-Ouk Shim, Ji-Yul Lee, Tae-Soo Lee, Min-Woong Lee, Wi Young Lee, Jin Kwon Ahn, Kang Hyeon Ka, Soo-Yong Song, Jeong-Hee Yun, Sang-Jun Kim, Ahn-Heum Eom, Eun-Hwa Lee, Suk Kim, Chang-Seok Lee, Yong-Seok Choi, Jae-Jin Kim, Young Woon Lim, Gyu-Hyeok Kim, Dae-Hyung Lee, Jae-Ho Kim, Kyo-Chul Koo, Dae-Hyoung Lee, Seung-Chan Jeong, Hyung-Eun Yoo, Jong-Soo Lee, Ahmed Imtiaj, Chandana Jayasinghe, Gun Woo Lee, Sang-Beom Kim, Yong Tae Jeong, Byung Keun Yang, Rezuanul Islam, Yu Sun Jung, Sang Min Kim, Chi Hyun Song, Sung-Hee Nam, Gyoo-Byung Sung, In-Mo Cheng, Hyeon Hur, Shun-Xing Guo, Young-Sang Choi, Hong Kyu Kim, Ka-Soon Lee, Dal-Soo Jhune, Jae-Mo Sung, Kyong-Cheol Ko, Sang Hyun Park, Hui Jeong Gwon, Yoshiyuki Kamio, Phuntip Poonpairoj, Yong-Sun Bahn, Young-Joon Ko, Joseph Heitman, In Ho Jeong, Mi Ra Park, Myoung Taek Lim, Kyu San Lee, Sung Je Cho, Gyoung Hee Kim, Sun Ho Shin, Hyun Su Park, Jong Sup Shin, Jong Young Yoon, Dong Heon Lee, Kyu Jin Yum, Myungkil Kim, Sun-Hwa Ryu, A-Young Lee, Bo-Young Kim, Kyung-Eun Lee, Young Hyun Kim, Hyoun-Su Lee, Joung Yoon Back, Young-Seok Kim, Man-Deuk Han, Ju-Yeon Sim, Kyung-Ha Yoon, Seung-Han Oh, Yoon Soo Han, Je-O Lee, Bhushan Shrestha, Sang-Kuk Han, Beom-Suk Kim, Gan-Joo Lee, Tae-Woong Kim, Ho-Gyoung Kim, Won-Ho Lee, Eun-Jung Ham, Sung-Su Park, Yong-Seon Yoo, Soo-Young Lee, Mi-Jeong Park, Young-Joon Choi, Seung-Beom Hong, Hyeon-Dong Shin, Jae-Gu Han, Sang Beom Kim, Geon Woo Lee, Tae Soo Lee, Mi Ja Shim, Chang-Won Lee, Hyun-Su Rho, Hyun Sook Lee, Min Woong Lee, U Youn Lee, Mi Sun Kim, Soon Ja Seok, Hack Sung Jung, Ji Yeon Oh, Sun Young Lee, Mun Il Ryoo, Ki Deok Kim, Hyo-Kyoung Won, Sung-Soon Kim, Dong-Gyu Kim, Song-Hee Lee, Hyeon-Su Ro, Hyun-Sook Lee, Narayan Chandra Paul, Won Ki Kim, Sung Kyoon Woo, Seung Hun Yu, So Hee Yun, Eun-Young Seo, Mi-Ran Lee, Chang Sun Kim, Won-Sik Kong, Kyeong-In Seo, Soon-Young Park, Kab-Yeul Jang, Young-Bok Yoo, Kwang-Ho Kim, Keun Kim, Quyvang Le, Shanliang Shi, Min Woo Hyun, Wook-Ha Park, Seung Yeol Son, Seong Hwan Kim, Kye Seung Jang, Wook Ha Park, Dong Youn Suh, Hyuk Woo Kwon, In Joung Back, Eun Sil Choi, Han Gyu Go, Chang Hyun You, Heon Dal Yoo, Yeo Hong Yun, Hyo Sun Jang, Young Bok Yoo, Won Sik Kong, Kab Yeul Jang, In Yeup Kim, Se Jong Oh, Chang Sung Jhune, Hyoun-Young Kim, Jong Hwa Kim, Yeong-Man Yu, Pil-Jae Maeng, Hee-Moon Park, Suhn-Kee Chae, Keon-Sang Chae, Kwang-Yeop Jahng, Dong-Min Han, Yoon-Gyo Lee, Jae-Chang Lee, Ki-Chul Chung, Kyung-ju Jung, Hyung-Guk Choi, In-Jin Park, and Duk-Soo Choi
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geography ,Infectious Diseases ,geography.geographical_feature_category ,Sparassis crispa ,biology ,Mycology ,Spring (hydrology) ,Botany ,Gibberella ,biology.organism_classification ,Microbiology - Abstract
Functional Analyses of Three Gα and One Gβ Subunits in Gibberella zeaeComparison between Wild Strains of Pitoporus betulinus Collected from a Single TreeEcological Study of Sparassis crispa in Gwan...
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- 2007
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32. Antimicrobial Effects and Resistant Regulation of Magnolol and Honokiol on Methicillin-Resistant Staphylococcus aureus
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Ju Kim, Seung-Il Jeong, Kwang Yeop Jahng, Su Young Kim, and Kang-Yeol Yu
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Honokiol ,Methicillin-Resistant Staphylococcus aureus ,Article Subject ,medicine.drug_class ,Antibiotics ,lcsh:Medicine ,Microbial Sensitivity Tests ,Pharmacology ,medicine.disease_cause ,General Biochemistry, Genetics and Molecular Biology ,Lignans ,Microbiology ,chemistry.chemical_compound ,Anti-Infective Agents ,medicine ,Hexanes ,Oxacillin ,General Immunology and Microbiology ,biology ,Plant Extracts ,lcsh:R ,Biphenyl Compounds ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Antimicrobial ,bacterial infections and mycoses ,Methicillin-resistant Staphylococcus aureus ,Magnolol ,Biphenyl compound ,Magnolia officinalis ,chemistry ,Staphylococcus aureus ,Research Article - Abstract
The antimicrobial killing activity toward methicillin-resistantStaphylococcus aureus(MRSA) has been a serious emerging global issue. In a continuing search for compounds with antibacterial activity against several microorganisms includingS. aureusand MRSA, ann-hexane extract ofMagnolia officinaliswas found to contain magnolol. This compound exhibited potent activity againstS. aureus, standard methicillin-susceptibleS. aureus(MSSA), and MRSA as well as clinical MRSA isolates. When combined with oxacillin, the antibacterial activities of magnolol and honokiol against the MRSA strain were increased compared to single treatment without antibiotics at 10 µg/mL and 25 µg/mL, respectively. These activities of magnolol and honokiol were dose dependent. Also, magnolol showed synergistic effects with oxacillin against 13 clinical isolates of MRSA. It was determined that magnolol and honokiol had a synergistic effect with oxacillin against MRSA strain. Furthermore, the magnolol inhibited the expression of the resistant genes,mecA, mecI, femA, andfemB, in mRNA. We concluded that the antibacterial activity of magnolol against MRSA strain is more related to themecI’s pathway and components of the cell wall thanmecR1. Therefore, the results obtained in this study suggest that the combination of magnolol and antibiotics could lead to the development of new combination antibiotics against MRSA infection.
- Published
- 2015
33. Abstracts of Presentations at the 2006 Fall Meeting of the Korean Society of Mycology at the Seoul Kyoyuk Munhwa Hoekwan, Seoul, Korea, October 19–20
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Yong-Bo Lee, Young-Hee Na, Chae-Kyu Lim, In-Hoa Jang, Dong-Kyoung Jang, Seong-Eun Yun, Sin-Ae Park, Sung-Hee Lim, Hyeon-Na Cho, Mi-Kyeong Lee, Yue-Qin Xiao, Young Jin Koh, Jae-Seoun Hur, Kwang-Mi Lim, Yoshikazu Yamamoto, Young-Ah Jeon, Hyo-Jin Kim, Myoung-Sook Shin, Seung-Joo Go, Seung-Beom Hong, Duck-Hyun Cho, Jin Sung Lee, Hack Sung Jung, Jae-Gu Han, Hyeon-Dong Shin, Young-Joon Choi, Dae-Ho Kim, Young-ah Jeon, Seung-Ju Go, Jong-Kyu Lee, Kab-Yeul Jang, Sun-Gyu Choi, Won-Sik Kong, Young-Bok Yoo, Gyu-Hyun Kim, Jae-Mo Sung, Jin Hee Kim, Ji Sun Lee, Ji Young Seo, Hyun-Su Rho, Hyun Sook Lee, Min Woong Lee, U-Youn Lee, Tae Soo Lee, Min Woo Hyun, Wook Ha Park, Ji Hye Kim, Jin Su Kim, Seung Kyu Lee, Kyung Hee Kim, Seong Hwan Kim, Imtiaj Ahmed, Jayasinghe Chandana, Sang Beom Kim, Ji Yeon Oh, Sam Nyu Jee, Hojoung Lee, Mun Il Ryoo, Ki Deok Kim, Sang Hyeon Park, Ahn Heum Eom, Narayan Chandra Paul, Won Ki Kim, Sung Kyoon Woo, Yun Woo Jang, Myung Soo Park, Seung Hun Yu, Miyeong Sim, Ahn-Heum Eom, Eun-Hwa Lee, Suk Kim, Yoo Mee Lee, Eui Nam Kim, Gun Woo Lee, VU Van Hanh, Suk Il Hong, Keun Kim, Keum Chul Shin, Jong Kyu Lee, Jong-Gab Jung, Moo-Hee Mun, Sang-Cheol Jun, Kyu-Joong Kim, Sang-Woo Kim, Young-Jae Kim, Eun-Jung Kim, Ji-Seon Min, Youn-Su Lee, Seung-Bin Kim, Moo-Young Jung, Man-Su Yu, Dong-Jun Kim, Hak-Ro Youn, Sung-Man Han, Kye Seung Jang, Yeo Hong Yun, Hun Dal Yoo, Hyo Sun Jang, Chung Hwa Lee, Je-O Lee, Sang-Kuk Han, Eun-Jeong Ham, Bhushan Shrestha, Ho-Kyoung Kim, Tae-Woong Kim, Won-Ho Lee, Su-Young Lee, Cheol-Soon Ko, Beom-Suk Kim, Jinju Kim, Hyun-Sook Lee, Hyeon-Su Ro, Kwang-Joon Chang, Kang-Hyeon Ka, Hyeon Hur, In-Pyo Hong, Jae-Ouk Shim, Tae-Soo Lee, Ji-Yul Lee, Min-Woong Lee, Ji Hwan Yoon, Ji Eun Park, Hyun Seok Jo, Dong Yeon Suh, Seung Beom Hong, Seung Ju Ko, Heng Luo, Mei Rong Ren, Kwon-Il Seo, Soon-Ok Rim, Jin-Hyung Lee, In-Joong Lee, In-Koo Rhee, Jong-Guk Kim, Sun Hwa Ryu, A Young Lee, Hee Kyoung Sohn, Myung Kil Kim, Ja-Young Yoon, Yun-Hee Park, Hee-Moon Park, Joong-Keun Lee, Seung-Moon Park, Moon-Sik Yang, Tai-Boong Uhm, Dae-Hyuk Kim, In-Yeup Kim, Chang-Sung Jhune, Kwang-Ho Kim, Young Bok Yoo, Won Sik Kong, Kab Yeul Jang, In Yeup Kim, Se Jong Oh, Chang Sung Jhune, Hye Jin Kwon, Yong Jin Park, Kap-Hoon Han, Yeong-Man Yu, Hyoun-Young Kim, Mi-Hee Choi, Pil-Jae Maeng, Jong Hwa Kim, Suhn-Kee Chae, Keon-Sang Chae, Kwang-Yeop Jahng, Dong-Min Han, Yaya Rukayadi, Jae-Kwan Hwang, Dong-Gyu Kim, Sung-Soon Kim, Jun-Oh Choi, Hyo-kyoung Won, Ji-Young Bae, Jung-Ah Choi, Sunhwa Moon, Jung-Bin Park, Eun-Hee Yang, Young-Hun Jin, Mi-Sun Lee, Mu-Seok Seo, Gun-A Kim, Seok-Tae Kwon, Young-Kyung Lee, Bum-Soo Hahn, Gi-Yong Kim, Beong-Yeol Sung, Jong-Bum Kim, Joo-Sung Yang, Seung Ho Lee, Mi Ja Shim, Jae Ouk Shim, Yoon Hee Lee, Jung Sun Lee, Hyun Guell Kim, Kyu Chan Cho, Yong Il Park, Wi Young Lee, Jin Kwon Ahn, Youngki Park, Kang Hyeon Ka, Jeong Weon Yoon, Sung Woo Choi, Hee Kuk Park, Won Jin Yu, Sung Pil Lee, Ae Kyung Juen, Won Woo Kim, Sang Mong Lee, Namsook Park, Eunju Park, Byung Rae Jin, Hong Kyu Kim, Yong Gyun Kim, Gwan Seuk Seo, Se Hyun Oh, Hong Gi Kim, Nam Gyu Kim, Sung Woo Kang, and Jung Bae Kim
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Myelochroa ,Euphoriomyces ,Opuntiella ,Infectious Diseases ,Genus ,Anthropology ,Mycology ,Laboulbeniales ,Biology ,biology.organism_classification ,Microbiology - Abstract
Notes on Three Species of the Genus Euphoriomyces (Laboulbeniales) from KoreaTaxonomic Studies on Myelochroa from KoreaMolecular Analysis of Korean Anzia opuntiella (Lichenized Ascomycota) Based on...
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- 2006
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34. An improved hydrophilicity via electrospinning for enhanced cell attachment and proliferation
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Kwang Yeop Jahng, Myung Seob Khil, Chi Hun Kim, Hyun Uk Lee, and Hak Yong Kim
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Male ,Vinyl alcohol ,Thermogravimetric analysis ,Materials science ,Scanning electron microscope ,Polyesters ,Biomedical Engineering ,macromolecular substances ,law.invention ,Biomaterials ,Contact angle ,chemistry.chemical_compound ,Coated Materials, Biocompatible ,Optical microscope ,law ,Materials Testing ,Microscopy ,Cell Adhesion ,Humans ,Composite material ,Cells, Cultured ,Cell Proliferation ,integumentary system ,Prostate ,technology, industry, and agriculture ,Epithelial Cells ,equipment and supplies ,musculoskeletal system ,Electrospinning ,chemistry ,Chemical engineering ,Polyvinyl Alcohol ,Microscopy, Electron, Scanning ,Wettability ,Wetting - Abstract
The wettability of electrospun poly(epsilon-caprolactone) (PCL) mats was improved by co-electrospinning with poly(vinyl alcohol) (PVA), by double-spinneret electrospinning method. The improved hydrophilicity of the hybrid PCL/PVA mats was confirmed by water contact angle measurement. The in vitro cell attachment on the hydrophobic PCL and hydrophilically modified PCL/PVA mats was compared by culture studies using human prostate epithelial cells (HPECs). The stability of water-soluble PVA component in the electrospun PCL/PVA mats was checked by thermogravimetric analysis and intensity of fluorescence material after immersion in water for 7 days. The images from scanning electron microscopy, field emission scanning electron microscopy, and optical microscopy showed that the attachment and proliferation rate of HPECs were improved by introducing PVA into the electrospun PCL mats.
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- 2006
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35. A Study on Oxidization Processes of YBaCuO Superconducting Thin Films in Atomic Force Microscope Anodization Lithography
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Kwang Yeop Jahng, Jong Bae Park, Hyeong−Gon Kang, and Haeseong Lee
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Superconductivity ,Fabrication ,Materials science ,Physics and Astronomy (miscellaneous) ,Anodizing ,business.industry ,Contact resistance ,General Engineering ,Analytical chemistry ,General Physics and Astronomy ,Biasing ,symbols.namesake ,symbols ,Optoelectronics ,Thin film ,Raman spectroscopy ,business ,Lithography - Abstract
It is essential to elucidate processing mechanism in the fabrication of nano-electronic devices in order to improve their characteristics. In this study, we systematically investigated various experimental parameters in oxidizing a thin film of YBaCuO superconductor, one of the processing steps in producing a superconducting flux flow transistor (SFFT). An area between a gate and a drain in SFFT was selectively modified by controlling the parameters such as an applied bias voltage between a conducting atomic force microscope (AFM) tip and the films, the numbers of the lithographic process on the same area, and the contact resistance between the sample holder and a sample. The height of the lithographed surface was increased with higher applied bias voltage, more numbers of the lithographic process, but was decreased by increasing the contact resistance. The analysis of the data confirmed that the height enhancement results from growth of oxide via an electrochemical reaction. Also analysis of its Raman spectra revealed that the electrical property of the oxidized area became an insulator. The peak 632 cm-1 related with the Cu?O stretching mode in the YBCO structure is disappeared or broad in a sample lithographed above 10 V, which means that the Cu?O chain is affected in superconducting structure by the AFM lithographic process.
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- 2006
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36. Abstracts of Presentations at the 2005 Fall Meeting of the Korean Society of Mycology at Seoul Kyoyuk Munhwa Hoekwan, Seoul, Korea, October 13–14
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Kye Seung Jang, Hee Jun Kang, Wook Ha Park, Sua Pyo, Seong Hwan Kim, Jin Sung Lee, Hack Sung Jung, Sun-Gyu Choi, Min-Goo Kim, Hyun-Min Kang, Won-Sik Kong, Young-Bok Yoo, Kab-Yeul Jang, Gyu-Hyun Kim, Soon-Ok Oh, Kwang-Mi Lim, Young-Jin Koh, Jae-Seoun Hur, Hosung Chung, Jee Hee Kim, Young Jin Koh, Myung Soo Pard, Geon Sik Seo, Kyung Sook Bae, Seung Hun Yu, Boo Hee Lee, Joo Chan Lee, Myung Soo Park, Dong-Soon Bae, Jung-Hwan Cha, Hyuk Gu Park, Han Gyu Ko, Jae Mo Sung, Won Mok Park, Yong-Bo Lee, Chae-Kyu Lim, Dong-Kyoung Jang, In-Ha Jung, Sang-Hee Park, In-Hwa Jang, Sung-Eun Yun, Hansu Park, Young Hyun Ryu, Woo Sik Jo, Sung Guk Choi, Jong Guk Kim, Jae Tak Yoon, Jung Sik Park, Su Young Kim, Hee-Gon Choi, Mira Jin, Kwang-Yeop Jahng, Kyung Seok Park, Jong-Chun Cheong, Chang-Sung Jhune, Jeong-Sik Park, Young-Ju Oh, Soo-Yeon Choi, Min-Sook Lee, Kum-Ju Park, Jung-il Kang, Hyo-Cheol Ha, Hyun-Su Kim, Byng-Keun Yang, Yong-Tae Jeong, Guk-Nam Kim, Hun Jeong, Chi-Hyun Song, Jae Won Lee, Soo Min Lee, Ji Yoon Lee, In Gyu Choi, Jae-Seong Hur, Wan Gyu Kim, Soon Ja Seok, Kang Hyo Lee, Hang Yun Weon, Yang Sup Kim, Sung-Keun Choi, Won-Ho Lee, Je-O Yi, Bum-Suck Kim, Jae-Mo Sung, Hae-Sook Jeon, Sung-Tae Yee, Ho Sung Chung, Min Woo Hyun, Han Byul Jang, Ji Hwan Yun, Sang Do Cha, Yeo Hong Yun, Seoung Ryul Son, Kyung-Ha Yoon, Hyoun-Su Lee, Sung-Keun Chioi, Jeong-Hoon Lee, In-Yeup Kim, Young-Hyun Lee, Hye-Kyung Jung, Yong Il Kim, Kwang Choon Chang, Youn Su Lee, Jae Ouk Shim, U Youn Lee, Tae Soo Lee, Min Woong Lee, Ki-Wook Kweon, Kwang-Ho Kim, Hee-Kyoung Kim, Sun-Hee Lee, Sae-Yeon Hong, Yin-Won Lee, Sung-Hwan Yun, Ki-Wook Kwon, Hyun-Dong Sin, Suk-Yi Woo, Yun-Hee Park, Hee-Moon Park, Joong Ho Joh, Nam Kuk Kim, Jong Hyun Lim, Min Jin Song, Won Sik Kong, Young Bok Yoo, Chang Soo Lee, Keum Chul Shin, Nam Kyu Kim, Byung Ju Cho, Jong Kyu Lee, Byung Ju Choi, Jaikoo Lee, Sang-Hyeon Park, Ahn-Heum Eom, Jin-Hyeuk Kwon, Seung-Beom Hong, Y. S. Lee, J. Y. Song, N. J. Jun, H. G. Kim, Kang-Hyo Lee, Soon-ja Seok, Gu-Bok Jung, Jong-Cheon Cheong, Soo-Muk Cho, Hyeon-Suk Jeong, Bong-Hyung Lee, Yoo-Mi Lee, In-Yong Kim, Jin-A Kim, YoungHak Park, KwangJae Lee, WonHo Lee, Kyung-Hee Kim, Myoung Yong Shim, Young Jae Jeon, Yun Hee Oh, Sang Beom Kim, Kyung Rim Lee, U Yoon Lee, In Pyo Hong, Sung Hee Nam, Gyoo Byung Sung, Hyun Bok Kim, I Yeon Jung, Pil Don Kang, Hyeon Hur, Min-Woong Lee, Jin-Hee Kim, Jung-Bo Sim, Jin Won Kim, and Se-Chul Chun
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Infectious Diseases ,Microbiology - Published
- 2005
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37. Numerical modeling of the superconducting flux flow transistor with a nanobridge
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Seokcheol Ko, Kwang-Yeop Jahng, Byoung-Sung Han, and Hyeong-Gon Kang
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Superconductivity ,Materials science ,General Computer Science ,Condensed matter physics ,business.industry ,Transistor ,General Physics and Astronomy ,Flux ,General Chemistry ,law.invention ,Magnetic field ,Computational Mathematics ,Optics ,Creep ,Mechanics of Materials ,law ,Condensed Matter::Superconductivity ,General Materials Science ,Photolithography ,business ,Penetration depth ,Electron-beam lithography - Abstract
We have fabricated superconducting flux flow transistors (SFFTs) with a nanobridge from epitaxial superconducting thin films by photolithography and electron-beam lithography. We have tried to simulate their I – V characteristics by building a model. The simulation was performed by varying the penetration depth as a function of the width and the thickness in the nanobridge and the gate current. This model showed the dependence of the critical current density on the spatial distribution of an applied magnetic field induced by the gate current. The simulated I – V curves were well in agreement with the measured curves in the flux creep regime of an SFFT with a nano-scale channel. This model is suitable for prediction of the I – V characteristics in the flux creep regime of the SFFT with a nano-scale channel.
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- 2005
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38. Characteristic variation of superconducting thin films modified by an atomic force microscope
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Hyeong-Gon Kang, Kwang-Yeop Jahng, Seokcheol Ko, and Haeseong Lee
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Superconductivity ,Materials science ,business.industry ,Transistor ,Analytical chemistry ,Biasing ,Electron microprobe ,STRIPS ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,law.invention ,Condensed Matter::Materials Science ,law ,Condensed Matter::Superconductivity ,Electric field ,Optoelectronics ,Thin film ,business ,Lithography - Abstract
Superconducting thin film surfaces were modified in order to test a possibility as a channel of superconducting flux flow transistor (SFFT) by AFM lithography. A conventional lithography method has been employed for superconducting strips which were patterned on LaAlO3 substrates. A region of the strips was selectively oxidized by an AFM probe in the presence of the electric field between the probe and the strip. Then the modified surface was analyzed by AFM, EPMA, and I-V curves. The thickness of the strips increases with the bias voltage as well as the scanning number due to the oxidation. The nonsuperconducting material produced by an AFM lithography process affects the characteristics of SFFT in the flux creep mode of I–V curves. This study represents a dynamic idea to fabricate the superconducting flux flow transistors with nano-channel by the AFM lithography. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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- 2005
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39. The GanB Gα-Protein Negatively Regulates Asexual Sporulation and Plays a Positive Role in Conidial Germination in Aspergillus nidulansSequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession no. AF198116
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Kwang-Yeop Jahng, Keon-Sang Chae, Mi-Hee Chang, and Dong-Min Han
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Hyphal growth ,Genetics ,biology ,Aspergillus nidulans ,Germination ,Mutant ,Conidiation ,Asexual sporulation ,biology.organism_classification ,Gene ,Conidium - Abstract
We isolated the ganB gene encoding the Gα-protein homolog from Aspergillus nidulans. To investigate the cellular function of GanB, various mutant strains were isolated. Deletion of constitutively inactive ganB mutants showed conidiation and derepressed brlA expression in a submerged culture. Constitutive activation of GanB caused a reduction in hyphal growth and a severe defect in asexual sporulation. We therefore propose that GanB may negatively regulate asexual sporulation through the BrlA pathway. In addition, deletion or constitutive inactivation of GanB reduced germination rate while constitutive activation led to precocious germination. Furthermore, conidia of a constitutively active mutant could germinate even without carbon source. Taken together, these results indicated that GanB plays a positive role during germination, possibly through carbon source sensing, and negatively regulates asexual conidiation in A. nidulans.
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- 2004
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40. The veA gene is necessary for the inducible expression by fructosyl amines of the Aspergillus nidulans faoA gene encoding fructosyl amino acid oxidase (amadoriase, EC 1.5.3)
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Hyo-Young Jeong, Myung Hoon Song, Vincent M. Monnier, Kwang-Yeop Jahng, Xinle Wu, Keon-Sang Chae, Jung Ho Back, and Dong-Min Han
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Molecular Sequence Data ,Mutant ,Fructose ,Biochemistry ,Microbiology ,Aspergillus nidulans ,Gene Expression Regulation, Enzymologic ,Gene Expression Regulation, Fungal ,Complementary DNA ,Gene expression ,Genetics ,Amino Acid Sequence ,Molecular Biology ,Gene ,Propylamines ,Sequence Homology, Amino Acid ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,Activator (genetics) ,Intron ,Nucleic acid sequence ,General Medicine ,biology.organism_classification ,Molecular biology ,Blotting, Southern ,Enzyme Induction ,Amino Acid Oxidoreductases - Abstract
The faoA gene encoding fructosyl amino acid oxidase (FAOD, EC 1.5.3) was isolated from Aspergillus nidulans and characterized. The complete nucleotide sequence of the faoA (fructosyl amino acid oxidase) gene and its cDNA revealed that the faoA gene encodes a 441-amino-acid polypeptide interrupted by five introns. Expression of the A. nidulans faoA gene was inducible by fructosyl propylamine and fructosyl lysine, as is the case for the gene encoding FAOD in other organisms. The faoA gene was not induced by these fructosyl amines in a null mutant of the veA gene, which has been identified as an activator of sexual development and as an inhibitor of asexual development; the faoA gene was induced greatly in a veA(+) wild-type. However, veA gene expression was not affected by fructosyl amines. Even in the absence of fructosyl propylamine, synthesis of the faoA transcript was higher in the veA(+) background than in a veA-null mutation background. These results indicated that faoA gene expression is inducible by fructosyl amines and by the veA gene, and that the veA gene is necessary for full induction of faoA gene expression by fructosyl amines. Thus, the faoA gene is the first gene whose expression is dependent on the veA gene. Furthermore, the faoA gene, present in a single copy, seems to be dispensable for development and growth, since the faoA-null mutant grew normally and developed as many conidia and sexual structures as the wild-type.
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- 2002
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41. Biosorption of cationic basic dye and cadmium by the novel biosorbent Bacillus catenulatus JB-022 strain
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Su Young Kim, Yeoung-Sang Yun, Mi Ra Jin, Kwang Yeop Jahng, Kang-Yeol Yu, and Chang Ho Chung
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Kinetics ,chemistry.chemical_element ,Bioengineering ,Bacillus ,Fractional Precipitation ,Wastewater ,Applied Microbiology and Biotechnology ,symbols.namesake ,chemistry.chemical_compound ,X-Ray Diffraction ,Cations ,Spectroscopy, Fourier Transform Infrared ,Biomass ,Fourier transform infrared spectroscopy ,Coloring Agents ,Cadmium ,Cationic polymerization ,Biosorption ,Langmuir adsorption model ,Hydrogen-Ion Concentration ,Phosphonate ,Field emission microscopy ,chemistry ,symbols ,Microscopy, Electron, Scanning ,Adsorption ,Biotechnology ,Nuclear chemistry - Abstract
Biosorption of heavy metals and dyes is a promising technology that involves the removal of toxic metals from industrial wastes. The present study aims to screen the bacterial strains isolated from soils and polluted pond for their potential biosorption of both cationic dye and cadmium. Bacillus catenulatus JB-022 strain removed 58% and 66% of cationic basic blue 3 (BB3) and cadmium (Cd(II)) at the respective concentrations of 2000 mg/L and 150 mg/L. The biosorption equilibrium data were well fitted by the Langmuir adsorption isotherm, and the kinetic studies indicated that the biosorption followed the pseudo-second-order model. The biosorption kinetics showed that the equilibrium was reached within 10 min and 5 min for BB3 and Cd(II), respectively. According to the Langmuir model, the maximum uptakes of BB3 and Cd(II) by the JB-022 biomass were estimated to be 139.74 and 64.28 mg/g, respectively. To confirm the surface morphology and functional groups, field emission scanning electron microscope, energy-dispersive X-ray spectrometer, X-ray diffraction, and Fourier transform infrared spectroscopy analyses were carried out, and the results revealed that the biomass of JB-022 has carboxyl and phosphonate groups as potential surface functional groups capable of binding to cationic pollutants. In conclusion, B. catenulatus JB-022 is proposed as an excellent biosorbent with potentially important applications in removal of cationic pollutants from wastewaters.
- Published
- 2014
42. The nsdD gene encodes a putative GATA-type transcription factor necessary for sexual development of Aspergillus nidulans
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Jae-Hyuk Yu, Kap-Hoon Han, Kyu-Yong Han, Dong-Min Han, Kwang-Yeop Jahng, and Keon-Sang Chae
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Genetics ,Complementation ,Zinc finger ,biology ,Aspergillus nidulans ,Mutant ,Asexual sporulation ,biology.organism_classification ,Molecular Biology ,Microbiology ,Gene ,Transcription factor ,Sexual reproduction - Abstract
The ability to reproduce both sexually and asexually is one of the characteristics of the homothalic ascomycete Aspergillus nidulans. Unlike the other Aspergillus species, A. nidulans undergoes sexual development that seems to be regulated by internal and external stimuli. To begin to understand the sexual reproduction of A. nidulans we previously isolated and characterized several NSD (never in sexual development) mutants that failed to produce any sexual reproductive organs, and identified four complementation groups, nsdA, nsdB, nsdC, and nsdD. The nsdD gene has been isolated, and it is predicted to encode a GATA-type transcription factor with the type IVb zinc finger DNA-binding domain. The mRNA of the nsdD gene started to accumulate in the early phase of vegetative growth, and the level increased as sexual development proceeded. However, it decreased during asexual sporulation and no nsdD mRNA was detected in conidia. Deletion of nsdD resulted in no cleistothecia (fruiting bodies) formation, even under the conditions that preferentially promoted sexual development, indicating that nsdD is necessary for sexual development. In contrast, when the nsdD gene was over-expressed, sexual-specific organ (Hulle cell) was formed even in submerged culture, which normally completely blocked sexual development, and the number of cleistothecia was also dramatically increased on solid medium. These results lead us to propose that the nsdD gene functions in activating sexual development of A. nidulans. Multiple copies of the nsdD gene could suppress nsdB5 and veA1, indicating that either nsdD acts downstream of these genes or possibly functions in overlapping pathway(s).
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- 2001
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43. The rpl16a Gene for Ribosomal Protein L16A Identified from Expressed Sequence Tags Is Differentially Expressed during Sexual Development of Aspergillus nidulans
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Kwang-Yeop Jahng, Keon-Sang Chae, Hyo-Young Jeong, and Dong Min Han
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Ribosomal Proteins ,Leucine zipper ,Saccharomyces cerevisiae Proteins ,Genes, Fungal ,Molecular Sequence Data ,Microbiology ,Aspergillus nidulans ,Fungal Proteins ,Ribosomal protein ,Gene Expression Regulation, Fungal ,Complementary DNA ,Genetics ,Amino Acid Sequence ,Northern blot ,Gene ,Gene Library ,Expressed Sequence Tags ,Expressed sequence tag ,Base Sequence ,biology ,Sequence Analysis, DNA ,biology.organism_classification ,Molecular biology ,GenBank - Abstract
We obtained 305 expressed sequence tags (ESTs), which are from the poly(A) site to the most proximal MboI site, from mycelia at the early sexual developmental (ESD) stage of Aspergillus nidulans. By comparison of these ESTs with those obtained previously from the vegetative stage and from the late sexual developmental stage followed by Northern blot analyses, genes of 17 ESTs were identified as being expressed more abundantly at the ESD stage than at the vegetative stage. Five of 17 genes were expressed more abundantly in the presence of the veA gene or the nsdD gene, suggesting that these 5 genes may be involved in sexual development. In a gene of one EST, appearing three times among 305 ESTs and identified by GenBank, polyadenylation seemed to occur at two sites. Nucleotide sequences of the gene having the EST and its cDNA revealed that the gene can code for a 202-amino-acid polypeptide with an estimated molecular mass of 23 kDa. The deduced amino acid showed 73% identity to Saccharomyces cerevisiae ribosomal protein L16A (RPL16A), and therefore the gene was named rpl16a. A. nidulans RPL16A had a putative leucine zipper motif and a basic leucine zipper motif like those of other organisms. The expression level of the rpl16a gene, present as a single copy in this organism, reached a maximum after 2 h, decreased thereafter, and increased again 30 to 50 h after the end of induction of sexual development. These results clearly indicated that the rpl16a gene is expressed differentially during sexual development.
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- 2000
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44. Dyadobacter jejuensis sp. nov., isolated from seawater
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Kiseong Joh, Ji Young Kang, Jeesun Chun, Haneul Kim, Kwang Yeop Jahng, and Yochan Joung
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DNA, Bacterial ,Sequence analysis ,Molecular Sequence Data ,Biology ,medicine.disease_cause ,Microbiology ,Dyadobacter jejuensis ,Phylogenetics ,Dyadobacter ginsengisoli ,RNA, Ribosomal, 16S ,Republic of Korea ,medicine ,Seawater ,Ecology, Evolution, Behavior and Systematics ,Phylogeny ,Base Composition ,Strain (chemistry) ,Phosphatidylethanolamines ,Fatty Acids ,Vitamin K 2 ,General Medicine ,Sequence Analysis, DNA ,Ribosomal RNA ,16S ribosomal RNA ,biology.organism_classification ,Flavobacteriaceae ,Bacterial Typing Techniques - Abstract
A taxonomic study was carried out on a novel bacterial strain, designated AM1R11T, which was isolated from seawater of Jeju Island in Korea. Cells of the isolate were found to be Gram-negative, rod-shaped and non-motile. Comparison of the 16S rRNA gene sequences indicated that the isolate belonged to the family Cytophagaceae , with Dyadobacter ginsengisoli Gsoil 043T as its closest relative, with a similarity of 96.6 %. It contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c, 36.9 %), iso-C15 : 0 (16.5 %) and C16 : 1ω5c (16.3 %) as the major fatty acids and MK-7 as the predominant menaquinone. The polar lipid profile of strain AM1R11T revealed the presence of phosphatidylethanolamine, one aminolipid and four unidentified lipids (L1, L2, L3 and L4). The DNA G+C content of strain AM1R11T was 45.1 mol%. On the basis of the evidence presented, it is concluded that strain AM1R11T represents a novel species of the genus Dyadobacter , for which the name Dyadobacter jejuensis sp. nov. is proposed. The type strain is AM1R11T ( = KACC 16446T = JCM 17918T).
- Published
- 2012
45. Predicting the chemical composition and structure of Aspergillus nidulans hyphal wall surface by atomic force microscopy
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Kwang-Yeop Jahng, Keon-Sang Chae, Hyun-uk Lee, Dong-Min Han, Haeseong Lee, and Jong Bae Park
- Subjects
beta-Glucans ,Hypha ,Hyphal tip ,Hyphae ,Chitin ,macromolecular substances ,Microscopy, Atomic Force ,Applied Microbiology and Biotechnology ,Microbiology ,Aspergillus nidulans ,Cell wall ,chemistry.chemical_compound ,Cell Wall ,Chemical composition ,Glucan ,chemistry.chemical_classification ,biology ,Chemistry ,fungi ,Proteins ,General Medicine ,Adhesion ,biology.organism_classification ,carbohydrates (lipids) ,Biophysics ,Protein Binding - Abstract
In fungi, cell wall plays an important role in growth and development. Major macromolecular constituents of the aspergilli cell wall are glucan, chitin, and protein. We examined the chemical composition and structure of the Aspergillus nidulans hyphal wall surface by an atomic force microscope (AFM). To determine the composition of the cell wall surface, the adhesion forces of commercially available beta-glucan, chitin, and various proteins were compared to those of corresponding fractions prepared from the hyphal wall. In both setups, the adhesion forces of beta-glucan, chitin, and protein were 25-50, 1000-3000, and 125-300 nN, respectively. Adhesion force analysis demonstrated that the cell surface of the apical tip region might contain primarily chitin and beta-glucan and relatively a little protein. This analysis also showed the chemical composition of the hyphal surface of the mid-region would be different from that of the apical region. Morphological images obtained by the tapping mode of AFM revealed that the hyphal tip surface has moderate roughness.
- Published
- 2008
46. The Aspergillus nidulans esdC (early sexual development) gene is necessary for sexual development and is controlled by veA and a heterotrimeric G protein
- Author
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Dong-Min Han, Kap-Hoon Han, Sung-Suk Lee, Jong-Hwa Kim, Hosun Moon, Kwang-Yeop Jahng, Keon-Sang Chae, and Serha Kim
- Subjects
Mutant ,Molecular Sequence Data ,medicine.disease_cause ,Microbiology ,Aspergillus nidulans ,Fungal Proteins ,Gene Expression Regulation, Fungal ,Genetics ,medicine ,Amino Acid Sequence ,Peptide sequence ,Gene ,Regulation of gene expression ,Mutation ,Glycogen binding ,Binding Sites ,biology ,Sequence Homology, Amino Acid ,fungi ,Wild type ,Gene Expression Regulation, Developmental ,biology.organism_classification ,Heterotrimeric GTP-Binding Proteins ,Introns - Abstract
The esdC (early sexual development) gene was isolated by using an expressed sequence tag (EST) as a probe from a genomic library of the early sexual developmental stage mycelia of Aspergillus nidulans. The sequence analysis revealed that the esdC gene contains a 59bp intron and encodes a 266 amino acid polypeptide with a calculated molecular weight of 29.4kDa. The EsdC protein is conserved among filamentous fungi and has a domain with similarity to a glycogen binding domain conserved in the beta subunit of the AMP-activated protein kinase (AMPK) complex. Although the esdD gene was expressed during asexual development, the expression reached its maximum at 10h and decreased thereafter up to 50h after the end of the induction of sexual development. In an esdC-null mutant under a veA(+) background, no sexual structures were formed at any condition examined. However, esdC overexpression did not lead to an induction of sexual development. In addition, to the effect of the esdC mutation on the sexual development, more conidiophores were formed in the esdC-null mutant than in a wild type. These results indicate that the esdC gene is necessary for sexual structure formation but its overexpression is not sufficient to enhance this process. Expression of the esdC gene throughout development was positively regulated by the veA gene. In addition, very little and no esdC transcript, respectively, was observed in an flbA-null mutant and in a fadA(G42R) mutant, and the esdC transcript level was higher in a fadA-null mutant and in a sfaD-null mutant than in a wild type, indicating that inactivation of FadA is necessary for positive regulation of esdC expression.
- Published
- 2007
47. Expression of the mnpA gene that encodes the mannoprotein of Aspergillus nidulans is dependent on fadA and flbA as well as veA
- Author
-
Kwang-Yeop Jahng, Keon-Sang Chae, Heeun Kim, Hyo-Young Jeong, and Dong-Min Han
- Subjects
Expressed Sequence Tags ,Fungal protein ,Expressed sequence tag ,Membrane Glycoproteins ,biology ,cDNA library ,fungi ,Mutant ,Sequence Analysis, DNA ,biology.organism_classification ,Microbiology ,Molecular biology ,Heterotrimeric GTP-Binding Proteins ,Aspergillus nidulans ,Fungal Proteins ,genomic DNA ,GTP-Binding Proteins ,Complementary DNA ,Genetics ,Gene - Abstract
The single copy mnpA gene that encodes a mannoprotein of Aspergillus nidulans and its cDNA were isolated from the genomic and cDNA libraries, respectively. The determined nucleotide sequences of the genomic DNA and its cDNA revealed that the gene has an open-reading frame of 261 amino acids without introns. The deduced amino acid sequence showed a 60% identity to that of Aspegillus fumigatus galactomannoprotein MP1. The mnpA gene was expressed more abundantly in the wild-type than in the veA-null mutant. It was expressed at a lower level in fadA-null mutants, veA(+) or veA1 (regardless of their genetic background), than in the fadA(+) strain. However, the expression level was slightly higher in the veA(+) DeltafadA strain than in the veA1 DeltafadA strain. Furthermore, the amount of the mnpA transcript was higher in the flbA(+) strain than in the flbA-null mutant. These results indicate that the fadA and flbA genes in addition to the veA gene are necessary for the mnpA expression. The mnpA gene was expressed highly in vegetative mycelia and at a reduced level in sexual structures, but not in conidia. Its expression was almost constitutive during asexual development up to 18h after the transfer of mycelial balls onto a solid medium, and decreased thereafter. During sexual development, its expression reached its maximum 0-20h after the induction of sexual development, and then decreased thereafter. The mnpA-null mutant, that was still viable, showed no phenotypic difference in development, growth rate, protein secretion, and germination of both the ascospores and conidia from the wild-type. This suggests that the mannoprotein that is encoded by the mnpA gene is dispensable.
- Published
- 2003
48. The veA gene activates sexual development in Aspergillus nidulans
- Author
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Kyung-Jin Kim, Hee-Seo Kim, Dong-Min Han, Kyu-Yong Han, Kwang-Yeop Jahng, and Keon-Sang Chae
- Subjects
Mutant ,Genes, Fungal ,Molecular Sequence Data ,Biology ,medicine.disease_cause ,Microbiology ,Aspergillus nidulans ,Fungal Proteins ,Open Reading Frames ,Start codon ,Gene Expression Regulation, Fungal ,Genetics ,medicine ,Amino Acid Sequence ,Gene ,Regulation of gene expression ,Mutation ,Base Sequence ,Neurospora crassa ,Nucleic acid sequence ,Wild type ,Molecular biology ,Open reading frame ,Phenotype - Abstract
The previously isolated gene complementing the veA1 mutation was confirmed to be the veA gene. The determined nucleotide sequence of the gene demonstrated that there is an open reading frame (ORF) of a 573 amino acid polypeptide. The nucleotide sequence matched some clones of which functions were not assigned yet and the amino acid sequence matched that of Neurospora crassa VeA-related protein with 61% similarity. The nucleotide sequence of the veA1 mutant gene differed from that of the wild type gene by only one nucleotide and the nucleotide G in the initiation codon ATG of the VeA ORF was mutated to the nucleotide T. Then, the mutant ORF may use the 37th methionine codon of the wild type one as a new initiation codon. The veA transcript was present in the conidia and in mycelia cultured for up to 14h and expressed almost constitutively at an increased level throughout the asexual and sexual developmental processes, suggesting that it may act from a relatively early developmental stage. Null mutants of the gene never formed sexual structures, even under conditions where sexual development preferentially occurs in wild types. Over-expressors of the gene formed larger numbers of sexual structures with a much reduced number of conidial heads than a control strain (a veA1 mutant), even under conditions where wild type strains form little sexual structure but form conidial heads very well, such as in the presence of a salt at high concentration. Furthermore, over-expressors could form Hulle cells and cleistothecia, even in a liquid culture. These results indicated that the veA gene is a positive regulator in sexual development and simultaneously a negative one in asexual development.
- Published
- 2002
49. Hepatocyte growth factor upregulates thymosin beta4 in human umbilical vein endothelial cells
- Author
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Kwang Yeop Jahng, Sang Sup So, Hwan Gyu Kim, and In Suk Oh
- Subjects
Angiogenesis ,medicine.medical_treatment ,Cell ,Biophysics ,Neovascularization, Physiologic ,Matrix metalloproteinase ,Biology ,Biochemistry ,Polymerase Chain Reaction ,Umbilical vein ,Culture Media, Serum-Free ,Extracellular matrix ,medicine ,Humans ,Molecular Biology ,Cells, Cultured ,Chromatography, High Pressure Liquid ,Hepatocyte Growth Factor ,Gene Expression Profiling ,Cell Biology ,Molecular biology ,In vitro ,Cell biology ,Up-Regulation ,Thymosin ,medicine.anatomical_structure ,Cytokine ,Matrix Metalloproteinase 2 ,Hepatocyte growth factor ,Endothelium, Vascular ,medicine.drug ,Signal Transduction - Abstract
Hepatocyte growth factor (HGF) is a mesenchymal-derived cytokine. It exerts in vitro a motogenic effect on various target cells, which is displayed either by cell scattering, locomotion, and migration during the wound repair process of cultured cells, or invasiveness through the extracellular matrix. Although it is known that HGF influences the motogenic effect of endothelial cells, the precise effects of HGF during angiogenesis are still poorly understood. To identify genes regulated via HGF signaling in HUVECs, we used the differential display polymerase chain reaction. In this study, thymosin beta4 was found to be differentially expressed in HGF-treated HUVECs compared with control. Data from HPLC profile and induction of MMPs indicate that HGF may affect the biological behavior of HUVECs through a combination of the direct effects of HGF itself and indirect effects mediated via induction of thymosin beta4 in vitro.
- Published
- 2002
50. Differential expression of house-keeping genes of Aspergillus nidulans during sexual development
- Author
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Jungmi Kim, Dong Min Han, Kwang-Yeop Jahng, Keon-Sang Chae, Hyo-Young Jeong, Kyu-Yong Han, and Ga-Bee Cho
- Subjects
TBX1 ,Ribosomal Proteins ,Molecular Sequence Data ,Pair-rule gene ,Gene Dosage ,Aspergillus nidulans ,Fungal Proteins ,Gene Expression Regulation, Fungal ,Gene expression ,Gene cluster ,Genetics ,Amino Acid Sequence ,ORFS ,Cloning, Molecular ,Gene ,Expressed Sequence Tags ,biology ,Base Sequence ,Sequence Homology, Amino Acid ,Gene Expression Regulation, Developmental ,General Medicine ,biology.organism_classification ,Molecular biology ,Actins ,Housekeeping gene - Abstract
The rpl3 gene and the rpl37 gene for Aspergillus nidulans ribosomal protein L3 (RPL3) and RPL37, which were identified as located on chromosome I and chromosome III, respectively, were isolated from chromosome-specific cosmid libraries. The nucleotide sequences of both of the rpl3 gene and the rpl37 gene identified the ORFs of 392 amino acids and 92 amino acids, respectively. Both of the two genes were present in a single copy. The expression of both genes together with two other house-keeping genes, the rps16 gene for RPS16 and the gene for γ -actin, was analyzed during sexual development. All four genes showed nearly identical expression patterns in that each gene expression reached its maximum after 2 h, decreased thereafter, and increased again after 30–40 h of induction of sexual development.
- Published
- 2001
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