Biomedical subjects

Kae Kyoung Kwon

Publications and source records attributed to Kae Kyoung Kwon.

7 recordsLinked to original sources

PubMed2006

Yeosuana aromativorans gen. nov., sp. nov., a mesophilic marine bacterium belonging to the family Flavobacteriaceae, isolated from estuarine sediment of the South Sea, Korea.

A marine bacterium, GW1-1T, capable of degrading benzo[a]pyrene (BaP), was isolated from estuarine sediments of the South Sea (the Korea Strait), Korea, after an enrichment culture maintained for 2 years in a medium supplemented with a mixture of BaP and pyrene. The strain formed yellowish-brown colonies on marine agar 2216. Cells were strictly aerobic, non-motile, Gram-negative rods and produced non-diffusible carotenoid pigments. Optimal growth occurred in the presence of 1 % (w/v) NaCl and at pH 7 and 33-36 degrees C. No growth occurred without supplementation with either CaCl2 or MgCl2, even in the presence of NaCl. Phylogenetic analysis based on the nearly complete sequence of the 16S rRNA gene revealed that the isolate formed a phyletic lineage with the genera Gelidibacter (93.9-94.7 % gene sequence similarity), Subsaximicrobium (93.3 %) and Subsaxibacter (93.9 %). The isolate also showed high sequence similarities to Gaetbulibacter saemankumensis (94.5 %), Algibacter lectus (94.2 %), members of the genus Bizionia (93.6-94.3 %) and Formosa algae (93.2 %), even though it belonged to a different phyletic line. The major respiratory quinones of the isolate were menaquinones MK-5 and MK-6. The DNA G+C content was 51.4 mol%. Dominant fatty acids were i-15 : 0, a-15 : 0, i-15 : 1omega10c and 16 : 1. On the basis of this polyphasic taxonomic evidence, strain GW1-1T is classified as a member of a novel genus and species in the family Flavobacteriaceae, for which the name Yeosuana aromativorans gen. nov., sp. nov. is proposed. The type strain of the type species is GW1-1T (=KCCM 42019T = JCM 12862T).

Benzo(a)pyrene↗

PubMed2006

Costertonia aggregata gen. nov., sp. nov., a mesophilic marine bacterium of the family Flavobacteriaceae, isolated from a mature biofilm.

A marine bacterium, strain KOPRI 13342(T), was isolated from a mature marine biofilm, including various marine algae, covering a rock-bed of the East Sea, Korea (also known as the Sea of Japan). Colonies of the isolate were orange-coloured on marine agar 2216. The isolate showed relatively high 16S rRNA gene sequence similarities to members of the genera Maribacter (91.2-92.4 % similarity), Zobellia (90.7-91.5 %) and Muricauda (90.7-91.4 %). Phylogenetic analysis based on the nearly complete 16S rRNA gene sequence revealed that the isolate formed a phyletic lineage with members of the genus Muricauda. Cells were aerobic, motile, Gram-negative rods and they produced non-diffusible carotenoid pigments. Optimal growth was observed at pH 7.5-8.0 and 26-32 degrees C and required the presence of 3 % (w/v) sea salt. The strain required Ca(2+) and K(+) ions in addition to NaCl for growth. The dominant fatty acids were i-15 : 0, i-15 : 1omega10, 15 : 0 and 16 : 1omega9. The major respiratory quinone was MK-6. The DNA G+C content was 35.8 mol%. On the basis of this polyphasic taxonomic evidence, strain KOPRI 13342(T) should be classified as a representative of a novel species in a new genus in the family Flavobacteriaceae; the name Costertonia aggregata gen. nov., sp. nov. is proposed. The type strain of Costertonia aggregata is KOPRI 13342(T) (=KCCM 42265(T) = JCM 13411(T)).

Biofilms↗

PubMed2006

Psychroserpens mesophilus sp. nov., a mesophilic marine bacterium belonging to the family Flavobacteriaceae isolated from a young biofilm.

A number of marine bacteria isolated from young biofilms were characterized as belonging to the family Flavobacteriaceae. The taxonomic characterization of strain KOPRI 13649T, which was isolated from an acrylic surface at the seashore at Gangneung, Korea, is reported here. The nearly complete 16S rRNA gene sequence of strain KOPRI 13649T was determined and was found to have a high level of similarity with that of Psychroserpens burtonensis (95.0-95.6 %). In addition, phylogenetic analysis and comparison with closely related strains confirmed that the strain represented a novel member of the genus Psychroserpens. The major respiratory quinone of strain KOPRI 13649T was MK-6 and the DNA G+C content was 29.8 mol%. The dominant fatty acid methyl esters were i-15 : 0, a-15 : 0, i-16 : 0, i-15 : 1omega10, 16 : 1omega7 and 15 : 0. Growth was observed at 10-34 degrees C (optimum 30 degrees C), at pH 6-9 (optimum 6.5-8.0) and with 0.5-4 % NaCl (optimum 1 %). On the basis of the polyphasic taxonomic evidence presented, strain KOPRI 13649T (=KCCM 42261T=JCM 13413T) should be classified as the type strain of a novel species in the genus Psychroserpens, for which the name Psychroserpens mesophilus sp. nov. is proposed.

Bacterial Typing Techniques↗

PubMed2006

Shewanella spongiae sp. nov., isolated from a marine sponge.

A psychrophilic bacterium, designated strain HJ039(T), was isolated from a marine sponge collected in the East Sea of Korea (also known as the Sea of Japan). Cells were Gram-negative, motile and rod-shaped (1.8-3.54 microm x 0.27-0.73 microm). Growth was observed between 5 and 26 degrees C (optimum 15 degrees C), at pH 5.0-8.5 (optimum pH 6.0-6.5) and in the presence of 0-6.0 % NaCl (optimum 2.0 %). The 16S rRNA gene sequence of strain HJ039(T) showed high levels of similarity (93.7-95.4 %) with members of the genus Shewanella, especially with Shewanella gaetbuli TF-27(T) (95.2 %), Shewanella decolorationis S12(T) (94.9 %), Shewanella putrefaciens LMG 26268(T) (94.6 %), Shewanella hafniensis P010(T) (94.6 %), Shewanella algae ATCC 51192(T) (94.5 %) and Shewanella kaireitica c931(T) (94.5 %). However, phylogenetic analysis revealed that strain HJ039(T) shared a phyletic line with S. algae and Shewanella amazonensis. The major respiratory quinone was Q-8. The DNA G+C content was 52.8 mol%. The major fatty acids were i-13 : 0 (8.5 %), 15 : 0 (4.2 %), i-15 : 0 (23.2 %), i-15 : 1 (7.9 %), 16 : 0 (8.7 %), 16 : 1omega7 (21.0 %) and 17 : 1omega8 (6.4 %). From this polyphasic taxonomic evidence, strain HJ039(T) is considered to represent a novel species of the genus Shewanella, for which the name Shewanella spongiae sp. nov. is proposed. The type strain is HJ039(T) (=KCCM 42304(T)=JCM 13830(T)).

Animals↗

PubMed2005

Kordiimonas gwangyangensis gen. nov., sp. nov., a marine bacterium isolated from marine sediments that forms a distinct phyletic lineage (Kordiimonadales ord. nov.) in the 'Alphaproteobacteria'.

A marine bacterium, designated strain GW14-5(T), capable of degrading high-molecular-mass polycyclic aromatic hydrocarbons was isolated from the sediments of Gwangyang Bay, Republic of Korea, after enrichment culture for 2 years with a mixture of benzo[a]pyrene and pyrene. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate forms a phyletic lineage that is distinct from the seven known orders within the 'Alphaproteobacteria'. 16S rRNA gene sequence similarity of strain GW14-5(T) to all recognized bacterial species was not greater than 92%. The dominant fatty acids of the isolate were i-17:1 (46.2%), i-15:0 (15.1%) and i-17:0 (12.6%). The major respiratory quinone was MK-5, and the DNA G+C content was 39.3 mol%. Cells of strain GW14-5(T) were Gram-negative, motile, catalase-positive, oxidase-positive and weakly halophilic. Glucose, N-acetylglucosamine and maltose were utilized as sole carbon sources. The strain was positive for beta-glucosidase activity. Optimal growth of strain GW14-5(T) was at pH 7.0 and 37-40 degrees C and required the presence of 2% (w/v) NaCl. On the basis of this evidence, strain GW14-5(T) represents a novel genus and species in the 'Alphaproteobacteria' for which the name Kordiimonas gwangyangensis gen. nov., sp. nov. is proposed. The novel order Kordiimonadales is proposed for the distinct phyletic line represented by the genus Kordiimonas. The type strain is GW14-5(T) (=KCCM 42021(T)=JCM 12864(T)).

Alphaproteobacteria↗

PubMed2004

Novel method for determining pyrene biodegradation using synchronous fluorimetry.

To study the biodegradation rate of pyrene dissolved in liquid medium supplemented with mineral salts, a synchronous fluorimetry (SF) method was established. The limit of detection for pyrene dissolved in mineral salts medium (MSM) was determined as 0.19 ng/ml with a relative standard deviation of less than 1.3% (n = 9). The pyrene degrading rates of four bacterial strains were investigated using this method under the same experimental conditions. The degradation rates of the three active strains ranged from 76% to 87% after a 14-h incubation. The results were confirmed by the gas chromatography with a flame ionized detector (GC/FID) method. This implies that pyrene degradation can be directly monitored by the SF method without the solvent extraction of samples. The advantages of SF are that it is less laborious, faster, and less expensive than the GC/FID determination method with solvent extraction. The SF method provides a new tool for studying the degradation of polynuclear aromatic hydrocarbons (PAHs) in the natural environment and under experimental conditions.

Bacteria↗

PubMed2004

Novosphingobium pentaromativorans sp. nov., a high-molecular-mass polycyclic aromatic hydrocarbon-degrading bacterium isolated from estuarine sediment.

A Gram-negative, yellow-pigmented, halophilic bacterial strain US6-1T, which degrades high-molecular-mass polycyclic aromatic hydrocarbons of two to five rings, was isolated from muddy sediment of Ulsan Bay, Republic of Korea. The 16S rRNA gene of the isolate showed high sequence similarity to Novosphingobium subarcticum (96.23 %) and Sphingopyxis alaskensis (96.18 %); however, the isolate formed a distinct phyletic line within the genus Novosphingobium. DNA-DNA relatedness between US6-1T and the closest strain N. subarcticum revealed that strain US6-1T was independent from this species. Isolate US6-1T had ubiquinone 10 and a DNA G + C ratio of 61.1 mol%. Major fatty acids were octadecanoic acid (18 : 1omega7), hexadecanoic acid (16 : 1omega7) and 2-hydroxy-myristic acid (14 : 0 2-OH). On the basis of polyphasic taxonomic evidence, strain US6-1T is proposed to represent a novel species in the genus Novosphingobium for which the name Novosphingobium pentaromativorans sp. nov. is proposed. The type strain is US6-1T (= KCTC 10454T = JCM 12182T).

Bacterial Typing Techniques↗