Jung-Eun Yang

Kyung Hee University, Seoul, Seoul, South Korea

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Publications (7)9.07 Total impact

  • Article: Chryseobacterium ginsenosidimutans sp. nov., a bacterium with ginsenoside-converting activity isolated from soil of a Rhus vernicifera-cultivated field.
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    ABSTRACT: A Gram-reaction-negative, strictly aerobic, non-motile, non-spore-forming, rod-shaped bacterial strain, designated THG 15(T), was isolated from soil of a field cultivated with Rhus vernicifera in Okcheon province, South Korea, and its taxonomic position was investigated by using a polyphasic approach. Strain THG 15(T) grew optimally at 25-30 °C and at pH 7 in the absence of NaCl on nutrient agar. Strain THG 15(T) displayed β-glucosidase (aesculinase) activity that was responsible for its ability to transform ginsenoside Rb(1) (one of the dominant active components of ginseng) into compound K via Rd and F(2). On the basis of 16S rRNA gene sequence similarities, strain THG 15(T) was shown to belong to the family Flavobacteriaceae and was most closely related to Chryseobacterium soldanellicola PSD1-4(T) (97.7 % sequence similarity), Chryseobacterium soli JS6-6(T) (97.5 %) and Chryseobacterium indoltheticum LMG 4025(T) (97.3 %). The G+C content of the genomic DNA was 35.7 mol%. The major menaquinone was MK-6 and the major fatty acids were iso-C(15 : 0) (50.3 %), iso-C(17 : 0) 3-OH (21.9 %), summed feature 4 (comprising C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH; 9.5 %) and iso-C(17 : 1)ω9c (9.3 %). DNA sequence analysis and chemotaxonomic data supported the affiliation of strain THG 15(T) to the genus Chryseobacterium. DNA-DNA relatedness values between strain THG 15(T) and its closest phylogenetic neighbours were <15 %. Strain THG 15(T) could be differentiated genotypically and phenotypically from recognized species of the genus Chryseobacterium. The isolate therefore represents a novel species, for which the name Chryseobacterium ginsenosidimutans sp. nov. is proposed. The type strain is THG 15(T) ( = KACC 14527(T)  = JCM 16719(T)).
    INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 06/2011; 61(Pt 6):1430-5. · 2.11 Impact Factor
  • Article: Flavobacterium ginsenosidimutans sp. nov., a bacterium with ginsenoside converting activity isolated from soil of a ginseng field.
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    ABSTRACT: A Gram-negative, aerobic, non-motile, non-spore-forming, yellow-pigmented, rod-shaped bacterium, designated strain THG 01(T), was isolated from the soil of a ginseng field in Pocheon province, South Korea, and its taxonomic position was investigated by using a polyphasic approach. Strain THG 01(T) grew well at 25-37 °C and pH 6.0-7.5 in the absence of NaCl on nutrient agar. On the basis of 16S rRNA gene sequence similarity data, strain THG 01(T) was shown to belong to the family Flavobacteriaceae and was related to Flavobacterium anhuiense D3(T) (97.5 % similarity), Flavobacterium johnsoniae UW101(T) (96.8 %) and Flavobacterium denitrificans ED5(T) (96.7 %). 16S rRNA gene sequence similarities between the novel strain and members of other recognized species within the family Flavobacteriaceae were less than 96.7 %. The G+C content of the genomic DNA of strain THG 01(T) was 32.1 mol%. Phenotypic and chemotaxonomic data (major menaquinone was MK-6 and major fatty acids were iso-C(15 : 0), iso-C(15 : 0) 3-OH and C(16 : 1)ω7c and/or C(16 : 1)ω6c ) supported the affiliation of strain THG 01(T) to the genus Flavobacterium. DNA-DNA hybridization experiments showed that DNA-DNA relatedness values between strain THG 01(T) and its closest phylogenetic neighbours were below 11 %. The results of physiological and biochemical tests enabled strain THG 01(T) to be differentiated genotypically and phenotypically from recognized species of the genus Flavobacterium. The isolate therefore represents a novel species, for which the name Flavobacterium ginsenosidimutans sp. nov. is proposed, with THG 01(T) ( = KACC 14525(T) = JCM 16720(T)) as the type strain.
    INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 06/2011; 61(Pt 6):1408-12. · 2.11 Impact Factor
  • Article: Sphingomonas ginsenosidimutans sp. nov., with ginsenoside converting activity.
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    ABSTRACT: The Gram-reaction-negative, strictly aerobic, non-motile, non-spore-forming, and rod-shaped bacterial strain designated Gsoil 1429(T) was isolated from the soil of ginseng cultivating field of Pocheon province in South Korea. This bacterium was characterized in order to determine its taxonomic position by using the polyphasic approach. Strain Gsoil 1429(T) grew well at 25-37°C and at pH 7.0 on R2A and nutrient agar without NaCl supplement. Strain Gsoil 1429(T) had -glucosidase activity, which was responsible for its ability to transform ginsenoside Rb1 (one of the dominant active components of ginseng) to F(2) via gypenoside XVII. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 1429(T) was shown to belong to the family Sphingomonadaceae and to be related to Sphingomonas yunnanensis YIM 003(T) (98.2% sequence similarity), S. phyllosphaerae FA2(T) (97.5%), S. koreensis JSS26(T) (97.3%), and S. asaccharolytica IFO 15499(T) (97.1%). The G+C content of the genomic DNA was 65.6%. The major respiratory quinone was Q-10 and the major fatty acids were summed feature 8 (comprising C(18:1) 7c/ωt/12t), C(16:0) and C(14:0)2OH. DNA and chemotaxonomic data supported the affiliation of strain Gsoil 1429T to the genus Sphingomonas. The DNA-DNA relatedness values between strain Gsoil 1429(T) and its closest phylogenetically neighbours were below 28%. Strain Gsoil 1429(T) could be differentiated genotypically and phenotypically from the recognized species of the genus Sphingomonas. The isolate therefore represents a novel species, for which the name Sphingomonas ginsenosidimutans sp. nov. is proposed, with the type strain Gsoil 1429(T) (=KACC 14949(T) =JCM 17074(T) =LMG 25799(T)).
    The Journal of Microbiology 12/2010; 48(6):760-6. · 1.10 Impact Factor
  • Article: Nocardioides ginsengisegetis sp. nov., isolated from soil of a ginseng field.
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    ABSTRACT: A Gram-positive, rod-shaped, non-spore-forming bacterium (Gsoil 485(T)) was isolated from the soil of a ginseng field located in Pocheon province in South Korea. This bacterium was characterized in order to determine its taxonomic position by using the polyphasic approach. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 485(T) was shown to belong to the family Nocardioidaceae and related to Nocardioides koreensis (96.8% 16S rRNA gene sequence similarity), Nocardioides basaltis (96.7%), Nocardioides salarius (96.7%), and Nocardioides sediminis (96.5%). The sequence similarity with other species that had validly published names within the genus Nocardioides was less than 96.4%. Strain Gsoil 485(T) was characterized chemotaxonomically as having LL-2,6-diaminopimelic acid in a cell-wall peptidoglycan, MK-8(H(4)) as the predominant menaquinone, and iso-C(16:0), C(18:1) ω9c as the major fatty acids. The G+C content of genomic DNA was 71.6 mol%. The chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain Gsoil 485(T) to the genus Nocardioides. The results of both physiological and biochemical tests allowed for genotypic differentiation of strain Gsoil 485(T) from the recognized Nocardioides species. Therefore, strain Gsoil 485(T) is considered to represent the novel species, for which the name Nocardioides ginsengisegetis sp. nov. is proposed, with the type strain Gsoil 485(T) (KACC 14269(T) =KCTC 19469(T) =DSM 21349(T)).
    The Journal of Microbiology 10/2010; 48(5):623-8. · 1.10 Impact Factor
  • Article: Panacagrimonas perspica gen. nov., sp. nov., a novel member of Gammaproteobacteria isolated from soil of a ginseng field.
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    ABSTRACT: A taxonomic study was carried out on Gsoil 142(T), a bacterial strain isolated from the soil collected in a ginseng field in Pocheon province, South Korea. Comparative 16S rRNA gene sequence studies showed a clear affiliation of this bacterium to the Gammaproteobacteria, and it was most closely related to Hydrocarboniphaga effusa ATCC BAA 332(T) (94.4%, 16S rRNA gene sequence similarity), Nevskia ramosa DSM 11499(T) (94.1%) and Alkanibacter difficilis MN154.3(T) (92.0%). Strain Gsoil 142(T) was a gram-negative, strictly aerobic, motile, and rod-shaped bacterium. The G+C content of the genomic DNA was 69.9% and predominant ubiquinone was Q-8. Major fatty acids were summed feature 8 (C(18:1) omega7c and/or omega6c, 36.3%), summed feature 3 (iso-C(15:0) 2-OH and/or C(16:1) omega7c, 20.6%) and C(16:0) (17.4%). The major polar lipids detected in strain Gsoil 142(T) were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and an unknown glycolipid. On the basis of polyphasic evidence, it is proposed that strain Gsoil 142(T) should be placed in a novel genus and species, for which the name Panacagrimonas perspica gen. nov., sp. nov. is proposed. The type strain is Gsoil 142(T) (= KCTC 12982(T) = LMG 23239(T)).
    The Journal of Microbiology 04/2010; 48(2):262-6. · 1.10 Impact Factor
  • Article: Synthesis and characterization of polystyrene-poly(arylene ether sulfone)-polystyrene triblock copolymer for proton exchange membrane applications.
    Jung-Eun Yang, Young Talk Hong, Jae-Suk Lee
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    ABSTRACT: The polystyrene-poly(arylene ether sulfone)-polystyrene (PS-PAES-PS) coil-semirod-coil triblock copolymer was synthesized by the condensation reaction of PS-COCI and H2N-PAES-NH2 telechelic polymers. The reaction was facile characterized by high yields with a perfect control over the block lengths. Following a known reaction protocol it was possible to selectively sulfonate the PS block of the triblock copolymer that led to the sulfonated copolymer sPS-PAES-sPS. Studies on its proton conductivity and methanol permeability were carried out to evaluate its use as the proton exchange membrane in direct methanol fuel cells. Proton conductivity of the membranes was increased depending on the sulfonic acid group content in the sulfonated polymer. The membranes exhibited good dimensional and thermal stability, and low methanol permeability compared to Nafion 117.
    Journal of Nanoscience and Nanotechnology 12/2006; 6(11):3594-8. · 1.56 Impact Factor
  • Article: Size control of polymeric nanoparticles from polystyrene-b-poly(2-vinylpyridine)
    Yoon-Hee Cho, Jung-Eun Yang, Jae-Suk Lee
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    ABSTRACT: We describe size control of polymeric nanoparticles prepared from an amphiphilic block copolymer, polystyrene-b-poly(2-vinylpyridine) (PS-P2VP). During the progress of quaternization between poly(2-vinylpyridine) block and methyl iodide, ionic interactions lead to strong aggregations of reverse micelles in methyl ethyl ketone (MEK). The size of the PS-P2VP nanoparticles with molecular weight of 12.6×104 was around 109 nm in MEK. When the dispersing medium of the nanoparticles was changed from MEK to toluene, the size of the nanoparticles was reduced from 109 to 73 nm. In addition, as the molecular weight of the PS-P2VP block copolymers was decreased, the size of the PS-P2VP nanoparticles was brought down up to 21 nm.
    Materials Science and Engineering: C. 24:293-295.

Institutions

  • 2011
    • Kyung Hee University
      • Department of Oriental Medicinal Materials & Processing
      Seoul, Seoul, South Korea
  • 2006
    • Gwangju Institute of Science and Technology
      • Department of Materials Science and Engineering
      Kwangju, Gwangju, South Korea