• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.337-345
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• 2005

The degradation of phenanthrene, a model PAH compound, by microorganisms either in the mixed culture or individual strain, isolated from oil-contaminated soil in oil refmery vicinity sites, was examined. The effects of pH, temperature, initial concentration of phenanthrene, and the addition of carbon sources on biodegradation potential were also investigated. Results showed that soil samples collected from four oil refinery sites in Korea had different degrees of PAH contamination and different indigenous phenanthrene-degrading microorganisms. The optimal conditions for phenanthrene biodegradation were determined to be 30$^{circ}C$ and pH 7.0. A significantly positive relationship was observed between the microbial growth and the rate of phenanthrene degradation. However, the phenanthrene biodegradation capability of the mixed culture was not related to the degree of PAH contamination in soil. In low phenanthrene concentration, the growth and biodegradation rates of the mixed cultures did not increase over those of the individual strain, especially IC10. High concentration of phenanthrene inhibited the growth of microbial strains and biodegradation of phenanthrene, but was less inhibitory on the mixed culture. Finally, when non-ionic surfactants such as Brij 30 and Brij 35 were present at the level above critical micelle concentrations (CMCs), phenanthrene degradation was completely inhibited and delayed by the addition of Triton X100 and Triton N101.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.726-731
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• 2003

The aim of this research was to identify candidate probiotic lactic bacteria among indigenous dadih lactic isolates. Dadih is an Indonesian traditional fermented milk of West Sumatra which is fermented naturally. Viability of the strain is critical in determining the capacity of lactic bacteria to induce immune stimulation as well as to colonize in the intestinal tract. Therefore, LAB are proposed to exert health promoting or probiotic effects in human, such as inhibition of pathogenic microflora, antimutagenic, and the reduction of cholesterol levels. This manuscript reports in vitro probiotic properties of indigenous dadih lactic bacteria, especially some important colonization factors in GI tract, such as lysozyme, acid and bile tolerance. Bile Salt Hydrolase (BSH) activity, spectrum of bacteriocin, and antimutagenic activity of bacterial cells were also assessed. Twenty dadih lactic isolates were screened further for their tolerance to low pH, at pH 2 and 3 as well as their bile tolerance. There were ten isolates classified as acid and bile acid tolerant, and further screened for lysozyme tolerance, BSH activity. The spectrum of bacteriocin activity of isolates was assayed using cell-free neutralized supernatants by agar spot test against variety of pathogens. Lc. lactis subsp. lactis IS-10285, IS-7386, IS-16183, IS-11857 and IS-29862, L. brevis IS-27560, IS-26958 and IS-23427, Leu.mesen.mesenteroides IS-27526, and L. casei IS-7257 each has good survival rate at low pH values and in the presence of lysozyme, and short lag time in the presence of 0.3 % oxgall. Lc. lactis subsp. lactis IS-11857 and IS-29862 each has high BHS activity, Lc. lactis subsp. lactis IS-10285 and IS-16183 each had a positive spectrum of bacteriocin activity against E. coli 3301 and Lysteria monocytogenes ATCC 19112, while L. brevis IS-26958 has high BHS activity as well as positive spectrum of bacteriocin against E. coli 3301, Lysteria monocytogenes ATCC 19112, and S. aureus IFO 3060. All of the ten dadih lactic strains performed in vitro acid and bile tolerance, indicating a possibility to reach the intestine alive, and display probiotic activities.

• Journal of Species Research
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• v.5 no.1
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• pp.188-200
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• 2016

During recent screening to discover indigenous prokaryotic species in South Korea, a total of 31 bacterial strains assigned to the class Gammaproteobacteria were isolated from a variety of environmental samples including soil, tidal flat, freshwater, seawater, and plant roots. From the high 16S rRNA gene sequence similarity (>98.7%) 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 31 species have been described in South Korea; therefore 5 species of 3 genera in the order Alteromonadales, 11 species of 3 genera in the order Pseudomonadales, 8 species of 6 genera in the order Enterobacteriales, 2 species of 1 genera in the order Vibrionales, 1 species of 1 genera in the order Oceanospirillales, 3 species of 3 genera in the order Xanthomonadales, and 1 species in the order Spongiibacter_o within the Gammaproteobacteia are reported for proteobacterial species found in South Korea. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section.

• Journal of Species Research
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• v.4 no.2
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• pp.109-126
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• 2015

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.

• Journal of Species Research
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• v.4 no.2
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• pp.97-108
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• 2015

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.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.248-257
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• 2019

In this study, we isolated about 70 bacterial strains from terrestrial and marine environments in Jeju island, and finally, total 21 strains were obtained based on the 16S ribosomal RNA gene sequence analysis. These isolated strains were classified into 16 genera of 5 classes and were identified as an unrecorded species in the Republic of Korea. As a result of the substrate utilization and capability for polymer degradation, the physiological phenotypes for acid resistance and halophilic bacteria were observed to be distinct from each other, except for some acid resistance strains. This study might provide basic information on utilization for indigenous microorganisms.

• Journal of Species Research
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• v.4 no.2
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• pp.137-144
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• 2015

As a result of the research project 'Survey and excavation of Korean indigenous species' to secure unrecorded species in Korea, a total of 14 unreported bacterial strains assigned to the phyla Deinococcus-Thermus and Bacteroidetes were isolated from various environmental habitats all around Korea. On the basis of 16S rRNA gene sequence similarity and affiliation to the clade with the closest species, it was concluded that the isolates represent deep groups of the phyla Deinococcus-Thermus and Bacteroidetes. There have been no records about these 14 unreported species in Korea; therefore 2 species of 2 genera in the class Deinococci within the phylum Deinococcus-Thermus, and 11 species of 9 genera in the class Flavobacteriia and one species in one genus in the class Sphigobacteriia within the phylum Bacteroidetes are described as unreported species found in Korea. Gram staining reaction, morphological and other biochemical characteristics are described in the species description section.

• Journal of Species Research
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• v.8 no.1
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• pp.97-108
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• 2019

For the collection of indigenous prokaryotic species in Korea, 35 strains within the class Actinobacteria were isolated from various environmental samples (animals and clinical specimens) in 2017. Each strain showed high 16S rRNA gene sequence similarity (>98.8%) and formed a robust clade with recognized actinobacterial species. The isolates were assigned to 35 species, 22 genera, 15 families, and 8 orders of the class Actinobacteria. There are no official descriptions of these 35 bacterial species in Korea. Morphological properties, basic biochemical characteristics, isolation source, and strain IDs are included in the species descriptions.

• Journal of Life Science
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• v.24 no.6
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• pp.694-699
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• 2014

Indigenous microorganisms play decisive roles in biodegradation. In this study, eighty strains of hydrocarbon-degrading microbes were isolated from Incheon Bay. Among them, 12 strains were selected by an oil film collapsing method. The bacterial strain 'Incheon9' was eventually selected based on its relatively higher lipase and emulsification activities, and was identified as Acinetobacter sp. (NCBI accession code: KF54854). The optimum condition for the growth and emulsification activity of Acinetobacter sp. Incheon9 was $20^{\circ}C$, pH 7, and 1% NaCl. The optimum time for the best production of biosurfactant was 72 hrs. The oil degradation ability of Acinetobacter sp. Incheon9 was investigated by measuring the residual oils in the culture medium by gas chromatography (FID). This research provides foundational data for eco-friendly environmental remediation by microorganisms.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.39-45
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• 2019

In 2017, as a study to discover indigenous prokaryotic species in Korea, a total of 6 bacterial strains assigned to the genus Pseudomonas were isolated from soil. From the high 16S rRNA gene sequence similarity (${\geq}99.5%$) and phylogenetic analysis with closely related species, the isolated strains were identified as independent Pseudomonas species which were unrecorded in Korea. The six Pseudomonas species were Pseudomonas mandelii, P. canadensis, P. thivervalensis, P. jessenii, P. lurida, and P. brenneri. Gram reaction, culture conditions, colony and cell morphology, basic physiological and biochemical characteristics are described in the species description section.