Biomedical subjects

Jongsik Chun

Publications and source records attributed to Jongsik Chun.

At least 37 records · Page 2Linked to original sources

PubMed2005

Hahella ganghwensis sp. nov., isolated from tidal flat sediment.

A marine bacterial strain, designated FR1050(T), was isolated from a sediment sample of getbol (Korean tidal flat). Phylogenetic investigations based on 16S rRNA gene sequence analysis showed that the isolate formed a robust monophyletic clade with Hahella chejuensis within the gamma-Proteobacteria. Sequence similarity between strain FR1050(T) and the type strain of Hahella chejuensis was 94.7 %. Cells were Gram-negative, aerobic, rod-shaped, motile and halophilic; optimum growth occurred at sea salt concentrations of 4-6 %. The major fatty acids were C(18 : 1)omega9c (39.0 %) and C(16 : 0) (18.1 %). The DNA G+C content was 44 mol%. The polyphasic data obtained showed that strain FR1050(T) is affiliated to the genus Hahella but represents a novel species for which the name Hahella ganghwensis sp. nov. is proposed. The type strain is FR1050(T) (=KCTC 12277(T)=JCM 12486(T)).

Base Composition↗

PubMed2005

Flavobacterium antarcticum sp. nov., a novel psychrotolerant bacterium isolated from the Antarctic.

A yellow-pigmented, Gram-negative and aerobic bacterial strain, designated AT1026(T), was isolated from a terrestrial sample from the Antarctic. Results of 16S rRNA gene sequence analysis indicated that the Antarctic isolate belonged to the genus Flavobacterium, with the highest sequence similarity to Flavobacterium tegetincola (96.4 %). Cells were non-motile, non-gliding and psychrotolerant, with optimum and maximum temperatures of about 20 and 25 degrees C. Flexirubins were absent. The major isoprenoid quinone (MK-6), predominant cellular fatty acids (iso-C(15 : 1) G, iso-C(15 : 0) and a mixture of C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH) and DNA G+C content (38 mol%) of the Antarctic isolate were consistent with those of the genus Flavobacterium. In contrast, several phenotypic characters can be used to differentiate this isolate from other flavobacteria. The polyphasic data presented in this study indicated that this isolate should be classified as a novel species in the genus Flavobacterium. The name Flavobacterium antarcticum sp. nov. is therefore proposed for the Antarctic isolate; the type strain is AT1026(T) (=IMSNU 14042(T)=KCTC 12222(T)=JCM 12383(T)).

Antarctic Regions↗

PubMed2005

Pseudomonas panacis sp. nov., isolated from the surface of rusty roots of Korean ginseng.

A Gram-negative, aerobic bacterium, designated CG20106(T), was isolated from the surface tissues of rusty root lesions of Korean ginseng. Phylogenetic analysis of the 16S rRNA gene sequence revealed that this isolate represents a hitherto unknown subline within the genus Pseudomonas. Strain CG20106(T) was catalase- and oxidase-positive, motile and rod-shaped. The overall phenotypic features of the ginseng isolate were similar to those of Pseudomonas cedrina, Pseudomonas migulae and Pseudomonas azotoformans. However, several physiological and chemotaxonomic properties can be weighted to distinguish the isolate from these organisms. The major fatty acids were C(16:1)omega7c and/or iso-C(15:0) 2-OH (summed feature 3, 36.4+/-0.4%), C(16:0) (27.5+/-0.7%) and C(18:1)omega7c (19.4+/-0.2%). The DNA G+C content was 61.4 mol%. On the basis of the polyphasic results revealed in this study, the name Pseudomonas panacis sp. nov. is proposed for strain CG20106(T). The type strain is CG20106(T) (=IMSNU 14100(T)=CIP 108524(T)=KCTC 12330(T)).

Bacterial Typing Techniques↗

PubMed2005

Pseudoalteromonas byunsanensis sp. nov., isolated from tidal flat sediment in Korea.

A Gram-negative, motile, strictly aerobic, violet-pigment-producing bacterium, designated strain FR1199T, was isolated from tidal flat sediment of Byunsan, South Korea. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain FR1199T represents a distinct line of descent within the genus Pseudoalteromonas. The phenotypic features of strain FR1199T were similar to those of Pseudoalteromonas phenolica and Pseudoalteromonas luteoviolacea, but several physiological and chemotaxonomical properties readily distinguished strain FR1199T from these species. Major fatty acids were straight-chain saturated (C(16 : 0)) and monounsaturated C(18 : 1)omega7c fatty acids. The DNA G+C content was 39 mol%. On the basis of polyphasic evidence, it is concluded that the isolate represents a novel species within the genus Pseudoalteromonas, for which the name Pseudoalteromonas byunsanensis sp. nov. is proposed. The type strain is FR1199T (=JCM 12483T=KCTC 12274T).

Base Composition↗

PubMed2005

Archaeal diversity in tidal flat sediment as revealed by 16S rDNA analysis.

During the past ten years, Archaea have been recognized as a widespread and significant component of marine picoplankton assemblages. More recently, the presence of novel archaeal phylogenetic lineages has been discovered in coastal marine environments, freshwater lakes, polar seas, and deep-sea hydrothermal vents. Therefore, we conducted an investigation into the archaeal community existing in tidal flat sediment collected from Ganghwa Island, Korea. Phylogenetic analysis of archaeal 16S rDNA amplified directly from tidal flat sediment DNA revealed the presence of two major lineages, belonging to the Crenarchaeota (53.9%) and Euryarchaeota (46.1%) phyla. A total of 102 clones were then sequenced and analyzed by comprehensive phylogenetic analysis. The sequences determined in our samples were found to be closely related to the sequences of clones which had been previously obtained from a variety of marine environments. Archaeal clones exhibited higher similarities (83.25-100%) to sequences from other environments in the public database than did those (75.22-98.46%) of previously reported bacterial clones obtained from tidal flat sediment. The results of our study suggest that the archaeal community in tidal flat sediment is remarkably diverse.

Archaea↗

PubMed2004

Kordia algicida gen. nov., sp. nov., an algicidal bacterium isolated from red tide.

A bacterium (named OT-1(T)) that showed algicidal activity was isolated from sea water of Masan Bay, Korea, during an outbreak of red tide. Phylogenetic analysis based on 16S rDNA sequences showed that the isolate formed a distinct phyletic lineage within the family Flavobacteriaceae of the Cytophaga-Flavobacterium-Bacteroides group. No species with a validly published name showed >/=93 % 16S rRNA gene sequence similarity to strain OT-1(T). The isolate had major amounts of iso-branched and 3-hydroxy iso-branched fatty acids and menaquinone 6 and a DNA G+C content of 34 mol%; these chemotaxonomic characters also supported the placement of the organism in the family Flavobacteriaceae. The strain was Gram-negative, yellow-pigmented, non-motile, non-gliding, flexirubin-negative, strictly aerobic, catalase-negative, oxidase-positive and halophilic. Na(+), Ca(2+) and Mg(2+) ions were obligately required for growth. The strain utilized various sugars as sole carbon sources and degraded gelatin, skimmed milk and starch. Several phenotypic characters can be used to differentiate the test strain from phylogenetically related marine bacterial genera. On the basis of polyphasic evidence, it is proposed that strain OT-1(T) should be assigned to the family Flavobacteriaceae as Kordia algicida gen. nov., sp. nov. The type strain is OT-1(T) (=KCTC 8814P(T)=NBRC 1000336(T)).

Animals↗

PubMed2004

Thalassomonas ganghwensis sp. nov., isolated from tidal flat sediment.

A Gram-negative, aerobic, halophilic bacterium, designated strain JC2041(T), was isolated from a sediment sample of getbol, the Korean tidal flat. Results of 16S rDNA sequence analyses indicated a moderate relationship to Thalassomonas viridans within the gamma-Proteobacteria (94.9 % similarity). Depending on the tree-making algorithm used, the isolate either formed a monophyletic clade with T. viridans or was recovered as a sister group of a class containing the genera Thalassomonas and Colwellia. Phenotypic features of the getbol isolate were similar to those of T. viridans, but several physiological and chemotaxonomic properties, including nitrate reduction, amylase, lecithinase, Tweenase and utilization of 13 carbon sources, distinguished strain JC2041(T) from T. viridans. The polyphasic data presented in this study indicate that the isolate should be classified as a novel species in the genus Thalassomonas. The name Thalassomonas ganghwensis sp. nov. is therefore proposed for the getbol isolate; the type strain is JC2041(T) (=IMSNU 14005(T)=KCTC 12041(T)=DSM 15355(T)).

Alteromonadaceae↗

PubMed2004

Aestuariibacter salexigens gen. nov., sp. nov. and Aestuariibacter halophilus sp. nov., isolated from tidal flat sediment, and emended description of Alteromonas macleodii.

Two strictly aerobic, halophilic strains of the gamma-Proteobacteria, designated JC2042(T) and JC2043(T), were obtained from a sediment sample of getbol, the Korean tidal flat. Comparative 16S rDNA sequence studies revealed that the test strains were related most closely to the type strains of the genera Alteromonas (93.5-95.5 %) and Glaciecola (91.1-93.3 %). Phylogenetic analyses demonstrated that strains JC2042(T) and JC2043(T) formed a distinct monophyletic clade within the family Alteromonadaceae and clustered distantly with the genera Alteromonas and Glaciecola. Physiological, biochemical and chemotaxonomic data also indicated that the two getbol isolates were significantly different from members of these two genera and others with validly published names. Cells were rod-shaped and motile with a polar flagellum. The major isoprenoid quinone was Q8. The predominant cellular fatty acids were C(16 : 0), C(18 : 1)omega7c and a mixture of C(16 : 1)omega7c and iso-C(15 : 0) 2-OH. DNA G+C contents were 48-54 mol%. On the basis of this polyphasic study, Aestuariibacter gen. nov. is proposed with two novel species, Aestuariibacter salexigens sp. nov. (type strain, JC2042(T)=IMSNU 14006(T)=KCTC 12042(T)=DSM 15300(T)) and Aestuariibacter halophilus sp. nov. (type strain, JC2043(T)=IMSNU 14007(T)=KCTC 12043(T)=DSM 15266(T)). Aestuariibacter salexigens is the type species of the genus. In addition, an emended description of Alteromonas macleodii is proposed.

Acetylglucosamine↗

PubMed2004

Hongiella mannitolivorans gen. nov., sp. nov., Hongiella halophila sp. nov. and Hongiella ornithinivorans sp. nov., isolated from tidal flat sediment.

Three marine strains of the Cytophaga-Flavobacterium-Bacteroides group, designated JC2050T, JC2051T and JC2052T, were obtained from a single sediment sample of getbol, the Korean tidal flat. Comparative 16S rDNA sequence studies revealed that the test strains were not closely related to any validly published genera and that these strains were only distantly related to the genus Cyclobacterium (88.7-91.2%). Phylogenetic analyses demonstrated that the three getbol isolates formed a distinct monophyletic clade within the family Cytophagaceae. Physiological, biochemical and chemotaxonomic data also indicated that these three getbol isolates differed significantly from members of other genera and were sufficiently different from each other to be recognized as separate species. On the basis of polyphasic evidence, a new genus, Hongiella gen. nov., is proposed, with three novel species, Hongiella mannitolivorans sp. nov. (type strain JC2050T=IMSNU 14012T=DSM 15301T), Hongiella halophila sp. nov. (type strain JC2051T=IMSNU 14013T=DSM 15292T) and Hongiella ornithinivorans sp. nov. (type strain JC2052T=IMSNU 14014T=DSM 15282T). Hongiella mannitolivorans is the type species of the genus.

Bacteroides↗

PubMed2004

Tsukamurella pseudospumae sp. nov., a novel actinomycete isolated from activated sludge foam.

The taxonomic position of two Tsukamurella strains isolated from activated sludge foam was clarified. The organisms, isolates JC85 and N1176T, were found to have chemical and morphological properties typical of members of the genus Tsukamurella. DNA-DNA relatedness studies showed that the strains formed a distinct genomic species that was most closely related to Tsukamurella spumae. The two isolates also share a range of phenotypic properties that distinguishes them from representatives of all species of Tsukamurella with validly published names. It is evident from the data that the two organisms should be classified as a novel Tsukamurella species, Tsukamurella pseudospumae sp. nov. The type strain is N1176T (=DSM 44118T=NCIMB 13963T).

Actinomycetales↗

PubMed2004

Phylogenetic analysis of the genera Streptomyces and Kitasatospora based on partial RNA polymerase beta-subunit gene (rpoB) sequences.

The RNA polymerase beta-subunit genes (rpoB) of 67 Streptomyces strains, representing 57 species, five Kitasatospora strains and Micromonospora echinospora KCTC 9549 were partially sequenced using a pair of rpoB PCR primers. Among the streptomycetes, 99.7-100 % similarity within the same species and 90.2-99.3 % similarity at the interspecific level were observed by analysis of the determined rpoB sequences. The topology of the phylogenetic tree based on rpoB sequences was similar to that of 16S rDNA. The five Kitasatospora strains formed a stable monophyletic clade and a sister group to the clade comprising all Streptomyces species. Although there were several discrepancies in the details, considerable agreement was found between the results of rpoB analysis and those of numerical phenetic classification. This study demonstrates that analysis of rpoB can be used as an alternative genetic method in parallel to conventional taxonomic methods, including numerical phenetic and 16S rDNA analyses, for the phylogenetic analyses of the genera Streptomyces and Kitasatospora.

DNA Primers↗

PubMed2004

Kribbella solani sp. nov. and Kribbella jejuensis sp. nov., isolated from potato tuber and soil in Jeju, Korea.

Two actinomycete strains, DSA1T and HD9T, were isolated from a potato tuber and soil from a potato-cultivating field in Jeju, Korea, respectively. A comprehensive 16S rDNA analysis revealed that the isolates belong to the genus Kribbella and share 97.7-98.6% sequence similarity to Kribbella species. The strains also contained typical chemotaxonomic markers of the genus Kribbella: ll-diaminopimelic acid, alanine, glycine and glutamic acid in the cell wall peptidoglycan; mannose, glucose, galactose and ribose as whole cell sugars; diphosphatidylglycerol, phosphatidylcholine and phosphatidylinositol as characteristic phospholipids; and the major menaquinone MK-9 (H4). DNA-DNA hybridization experiments showed that the isolates represented two distinct genomic species. A number of phenotypic properties can be used to differentiate the two isolates from Kribbella species. On the basis of polyphasic evidence, two novel species are proposed: Kribbella solani sp. nov. for strain DSA1T (=KACC 20196T=JCM 12205T) and Kribbella jejuensis sp. nov. for strain HD9T (=KACC 20266T=JCM 12204T).

Actinomycetales↗

PubMed2004

Serinicoccus marinus gen. nov., sp. nov., a novel actinomycete with L-ornithine and L-serine in the peptidoglycan.

A Gram-positive bacterial strain containing L-ornithine as the diagnostic diamino acid was isolated from a sea-water-sample from the East Sea, Korea. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain JC1078T represents a phyletic line within the suborder Micrococcineae of the order Actinomycetales, adjacent to the genus Ornithinimicrobium. The highest sequence similarity values to the isolate were observed against Ornithinimicrobium humiphilum (94.3 %) and Kytococcus sedentarius (94.1 %). The strain was strictly aerobic and moderately halophilic with optimal growth at 2-3 % (w/v) NaCl. Cells were non-motile, non-sporulating and coccoid-shaped. The cell wall contains L-ornithine, glutamic acid, alanine, glycine and serine. The major menaquinone was MK-8(H4). The predominant cellular fatty acids were of the iso- and anteiso-methyl-branched types. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and an unknown glycolipid. The acyl type of the glycan chain of peptidoglycan is acetyl. The DNA G + C content was 72 mol%. The combination of physiological, biochemical and chemotaxonomical data clearly separated the marine isolate from other members of the suborder Micrococcineae. On the basis of polyphasic evidence, it is proposed to classify strain JC1078T in a novel genus and species, for which the name Serinicoccus marinus gen. nov., sp. nov. is proposed. The type strain is JC1078T (= IMSNU 14026T = KCTC 9980T = DSM 15273T).

Actinomycetales↗

PubMed2004

Nocardioides ganghwensis sp. nov., isolated from tidal flat sediment.

A strictly aerobic, non-motile, rod-shaped actinomycete strain, named JC2055T, was isolated from a sediment sample of getbol, the tidal flat of Korea. 16S rDNA analysis revealed that the getbol isolate belonged to the genus Nocardioides with the highest sequence similarity to Nocardioides aquiterrae GW-9T (95.5%). The major menaquinone was MK-8(H4) and the predominant cellular fatty acids were iso-16 : 0 and 17 : 1omega8c. Tuberculostearic acid was absent. The G+C content of DNA was 72 mol%. Based on the morphological, physiological, biochemical and chemotaxonomical data presented in this study, strain JC2055T can be readily differentiated from other validly named Nocardioides species. The name Nocardioides ganghwensis sp. nov. is proposed for the isolate. The type strain is JC2055T (=IMSNU 14028T=KCTC 9920T=JCM 12124T).

Actinomycetales↗

PubMed2004

Clostridium jejuense sp. nov., isolated from soil.

A strictly anaerobic, mesophilic, endospore-forming bacterium, designated strain HY-35-12T, was isolated from a soil sample in Jeju, Korea. Cells of this isolate were Gram-positive, motile rods that formed oval to spherical terminal spores. Strain HY-35-12T grew optimally at 30 degrees C, pH 7.0 and 0-0.5 % (w/v) NaCl. The isolate produced pyruvate, lactate, acetate, formate and hydrogen as fermentation end products from glucose. The G + C content of DNA of the isolate was 41 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the organism formed a monophyletic clade with Clostridium xylanovorans and Clostridium aminovalericum in cluster XIVa of the genus Clostridium. The closest phylogenetic neighbour was C. xylanovorans, with 96.65 % 16S rRNA gene sequence similarity. Several physiological and chemotaxonomic properties were identified that enable strain HY-35-12T to be distinguished from phylogenetically related clostridia. On the basis of polyphasic characteristics, it is proposed that strain HY-35-12T (= IMSNU 40003T = KCTC 5026T = DSM 15929T) represents a novel species, Clostridium jejuense sp. nov.

Acetic Acid↗

PubMed2004

Nocardioides aestuarii sp. nov., isolated from tidal flat sediment.

A strictly aerobic, non-motile, rod-shaped actinomycete, designated strain JC2056(T), was isolated from a sediment sample of getbol, the tidal flat of Korea. Results of 16S rRNA gene sequence analysis indicated that the isolate belonged to the genus Nocardioides, with the highest similarity being to Nocardioides luteus KCTC 9575(T) (95.7 %). The major menaquinone was MK-8(H(4)), and predominant cellular fatty acids were iso-16 : 0 and iso-16 : 1 H. The DNA G+C content was 70 mol%. Based on the morphological, physiological, biochemical and chemotaxonomical data presented in this study, strain JC2056(T) should be classified as a novel species, for which the name Nocardioides aestuarii sp. nov. is proposed; the type strain is JC2056(T) (=IMSNU 14029(T)=KCTC 9921(T)=JCM 12125(T)).

Actinomycetales↗

PubMed2004

Phylogenetic characterization of Legionella-like endosymbiotic X-bacteria in Amoeba proteus: a proposal for 'Candidatus Legionella jeonii' sp. nov.

The X-bacteria which initiated organismic association with the D strain of Amoeba proteus in 1966 as parasites have changed to obligate endosymbionts on which the host depends for survival. Owing to the difficulty in cultivating the bacteria in vitro, the identity of X-bacteria has not been determined. As the life cycle of X-bacteria is similar to that of Legionella spp. in soil amoebae, we applied the polymerase chain reaction method with specific primers aimed at Legionella spp. for the detection and cloning of 16S rRNA gene. The identity and intracellular localization of the endosymbiont were confirmed by the application of a specific fluorescently labelled 16S rRNA-targeted probe. In addition we cloned RNA polymerase beta-subunit gene (rpoB) of X-bacteria by genomic library tagging. A phylogenetic analysis of the 16S rRNA gene placed the bacterium within a unique monophyletic group containing all other members of the genus Legionella. Phylogeny from rpoB and mip genes further confirmed the taxonomic context of X-bacteria to be a Legionella sp. In all three phylogenic analyses, X-bacterium was placed apart from Legionella-like amoebal pathogens present in soil amoebae. Thus, we propose the name 'Candidatus Legionella jeonii' sp. nov. for the endosymbiotic X-bacteria in Amoeba proteus.

Amino Acid Sequence↗

PubMed2004

A method for comparing multiple bacterial community structures from 16S rDNA clone library sequences.

Culture-independent approaches, based on 16S rDNA sequences, are extensively used in modern microbial ecology. Sequencing of the clone library generated from environmental DNA has advantages over fingerprint-based methods, such as denaturing gradient gel electrophoresis, as it provides precise identification and quantification of the phylotypes present in samples. However, to date, no method exists for comparing multiple bacterial community structures using clone library sequences. In this study, an automated method to achieve this has been developed, by applying pair wise alignment, hierarchical clustering and principle component analysis. The method has been demonstrated to be successful in comparing samples from various environments. The program, named CommCluster, was written in JAVA, and is now freely available, at http://chunlab.snu.ac.kr/commcluster/.

Algorithms↗