• Mycobiology
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• v.33 no.2
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• pp.109-112
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• 2005

The internal transcribed spacer (ITS) regions including the 3'-end of 18S rRNA gene, 5.8S rRNA gene and the 5'-end of the 28S rRNA gene of Rhizopus spp. were amplified by PCR and analyzed by DNASIS program. Length polymorphism of these region ranged from 564 bp in R. oryzae to 789bp in R. stolonifer. The length and sequence of 5.8S was very conserved with $154{\sim}155\;bp$. The sequence of ITS2 was more variable than that of ITS1. The base substitution rates were ranged from 0 to 0.6069 per site, and higher rate was found in R. stolonifer. In general, transition was usually more frequent than transversion. On the basis of sequencing results, four groups were clustered with value of 61.9% similarity; R. oryzae, R. micros pores, R. homothallicus, and R. stolonifer groups.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.85-91
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• 2002

The sequences of the internal transcribed spacers (ITS1 and ITS2) and 5.8S ribosomal DNA gene from five Cordyceps species and one Paecilomyces japonica were determined. The total length of the ITSI, 5.8S and ITS2 regions ranged from 528 to 549 bp. When the C. militaris collected from Korea was used as a standard genotype, the sequence showed 88.4%, 88.6%, 91.1% and 86.8% identity to C. pruinosa, C. sphecocephala, C. scarabaeucika and R japonica, respectively, while the lowest identity was found with C. sinensis (75.4%). Interestingly, C. sinensis was phylogenetically distant from the other Cordyceps species. To test geographic variation, furthermore, sequences of the ITS regions in the 8 samples of C. militaris collected from two localities in Korea and China analyzed and compared with the GenBank-searched sequences from Japan and China. The total length of the ITS regions of C. militaris from Korea, Japan and China was completely identical to each other with 528 bp, and the sequence divergence among three localities in pairwise comparisons ranged from 0.2% (1 bp) to 0.4% (2 bp).

• Journal of Species Research
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• v.11 no.3
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• pp.162-168
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• 2022

Compared to marine dinoflagellates, freshwater species are rarely recorded in Korea. In the present study, we isolated a freshwater dinoflagellate, Palatinus, from the Paldang Reservoir, Korea, in December 2021. The overall cell shape was ovoid, and the cell size was 34.3 ㎛ in length (25.8-39.5 ㎛) and 28.4 ㎛ in width (21.5-34 ㎛). An eyespot was usually observed near the sulcal region. The Kofoidian plate formula of the species was determined to be 4', 2a, 7", 6c, 5s, 5''', and 2''''. Apical pore complex was not observed. However, variations in the cingular plate caused by the fusion of 3C and 4C were observed. Analyses of 28S rDNA sequences revealed that the unidentified species is 100% similar to Palatinus apiculatus, and clustered together in the same lineage in the phylogenetic tree (100% bootstrap value). Our findings confirmed that the isolated dinoflagellate is Palatinus apiculatus, which was discovered for the first time in Korean freshwaters.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.259-266
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• 1987

A total of 129 clinical isolates of Staphylococcus species was characterized by the tests of coagulase production, haemagglutination, mannitol fermentation, DNase production and hemolysis. Ninety-nine out of them showed positive reactions to the tests, therefore they were identified as Staphylococcus aureus. The isolates showing positive reaction in haemagglutination test also showed 100% of tube coagulase positive reaction. The haemagglutination test was a reliable method for identifying Staphylococcus aureus in the clinical laboratory. S. aureus produced stronger hemolysis with human blood agar than with sheep blood agar. Antibiotic resistant S. aureus isolates(S-46, S-112, S-126) had 4 to 6 p]asmid DNA elements. The S-112 strain had 6 plasmid DNA elements(1.8, 2.2, 3.7, $26.3{\sim}50$, and 70 Mdaltons), the S-126 had 4 elements(2.6, 4.2, $4.6{\sim}60Md$), and the S-46 had 1 element(${\sim}100Md$). PPSA strain had 4 plasmid DNA elements(2.5, 4.2, $4.6{\sim}60Md$) and S. aureurs(ATCC) strain contained 9.4, 26.3 and ${\sim}50Md$ plasmid DNA elements.

• The Journal of Korean Medicine
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• v.32 no.5
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• pp.41-49
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• 2011

Objectives: To optimize the preservation method of herbal decoction, we investigated the content of principle components of Pyungwi-san, liquiritin, glycyrrhizin, and hesperidin according to preservation temperature and period. We also investigated the changing patterns of pH and microbial population in Pyungwi-san decoction as a model case. Methods: With samples preserved at different temperatures, the content of liquiritin, glycyrrhizin, and hesperidin was determined using HPLC and microbial population was determined as viable counting method up to 8 times every month. Identification of isolated bacteria was performed by 16S rDNA analysis. Results: The content of liquiritin and glycyrrhizin did not change according to the preservation temperature and period, but that of hesperidin was severely decreased at room temperature. The isolate from the decoction was identified as Bacillus licheniformis by 16S rDNA sequence analysis. Microbial population appeared after 3 months' preservation and reached maximum value at 4 months; at all tested temperatures, the pH showed the lowest value (4.4-4.5) simultaneously. Conclusion: From the results, it seems to be that the microbial growth affects the pH of preserved decoction but not the change of liquiritin and glycyrrhizin content.

• KSBB Journal
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• v.26 no.5
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• pp.407-411
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• 2011

Microbial fuel cell (MFC) wes enriched using sludge in wastewater treatment. The microbial community of activated sludge and enriched MFC were analyzed by FISH (fluorescent in situ hybridization) and 16S rDNA sequencing. Bacteroidetes group were pre-dominant in activated sludge by FISH. ${\alpha}$ group, ${\gamma}$ group and Acintobacter group were dominant and they were similar to distribution. The average value of 10 peak of MFC is 0.44C. When MFC wase enriched by sludge, ${\gamma}$-Proteobacteria, Plantomycetes group increased 70% and 60%, respectively. In results of 16S rDNA sequencing, Sphiringomonas sp. was comprised in ${\alpha}$ proteobacteria and Enterobacter sp., Klebsiella sp., Acinetobacter sp., Bacillus sp. were comprised in ${\gamma}$ proteobacteria and Chryseobacterium sp. was comprised in Flavobacteria were isolated from sludge.

• Journal of fish pathology
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• v.22 no.3
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• pp.391-400
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• 2009

Genetic identification of 17 fish-derived Aeromonas strains was attempted using 5 housekeeping genes. 16S rRNA, gyrB, rpoD, dnaJ and recA genes from the 17 strains were amplified, and total of 85 amplicons were sequenced. DNA sequences of the strains and type strains of the 17 Aeromonas homology groups were used for genetic identification and phylogenetic analyses. None of the strains was identified as a single species using the 16S rRNA gene, showing the same identities (average = 99.7%) with several Aeromonas species. According to gyrB, rpoD, dnaJ, and recA, 9 strains and RFAS-1 used in this study were identified as A. hydrophila and A. salmonicida, respectively. However, the other strains were closely related to 2 or more Aeromonas species (i.e., A. salmonicida, A. veronii, A. jandaei, A. media and A. troda) depending on the genetic marker used. In this study, gyrB, rpoD, dnaJ and recA gene sequences proved to be advantageous over 16S rRNA for the identification of field Aeromonas isolates obtained from fish. However, there are discrepancies between analyses of different phylogenetic markers, indicating there are still difficulties in genetic identification of the genus Aeromonas using the housekeeping genes used in this study. Advantages and disadvantages of each housekeeping gene should be taken into account when the gene is used for identification of Aeromonas species.

• Journal of Life Science
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• v.28 no.3
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• pp.361-368
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• 2018

This study investigated the diversity of communities of intestinal microorganisms, separated from the intestinal organs of Red tilefish (Branchiostegus japonicas), collected on the Jeju Coast. First, in the isolation of 1.5% BHIA, MA, TSA and R2A Agar on the medium, there were most colonies in 1.5% BHIA. The results of aerobic culture and anaerobic culture were $1.7{\times}10^6CFU/g^{-1}$ and $1.1{\times}10^5cfu/g^{-1}$, respectively, on average, and 147 pure colonies were separated in total. In 16S rDNA sequencing, there were 58 genera and 74 species, showing 95-100% similarity with the basic strain. They were divided broadly into 5 phyla, and as the main phyletic group, Proteobacteria phylum comprised 50% with 9 families, 35 genera and 35 species of Moraxellaceae, Rhodobacteraceae, Shewanellae, Halomondaceae, Enterobacteriaceae, Vibrionaceae, Hahellaceae, Pseudomonadaceae, and Erythrobacteraceae, with the highest index of dominance. Actinobacteria phylum comprised 24% with 8 families, 11 genera and 17 species of Microbacteriaceae, Intrasporangiaceae, Dietziaceae, Dermabacteraceae, Dermacoccaceae, Nocardiodaceae, Brevibacteriaceae and Propionobacteriacea; Firmicutes phylum, 16% with 6 families, 8 genera and 17 species of Bacillaceae, Staphylcoccaceae, Planococcaceae, Streptococcaceae, Paenibacillaceae and Clostridiaceae; Bacteroidetes phylum, 6% with 2 families, 3 genera and 4 species of Cyclobacteriaceae and Flavobacteriaceae; and Deinococcus-Thermus phylum, 4% with 1 family, 1 genus and 1 species of Deinococcaceae.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.116-124
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• 2006

In this study was performed to analyze quantitatively the number of viable but non-culturable bacteria in the Pine and Quercus forest soil by improved direct viable count (DVC) and plate count (PC) methods. The number of living bacteria of Pine and Quercus forest soil by PC method were less then 1% of DVC method. This result showed that viable but non-culturable (VBNC) bacteria existed in the forest soil with high percentage. Diversity and structure of VBNC bacterial populations in forest soil were analyzed by direct extracting of DNA and 16S rDNA-ARDRA from Pine and Quercus forest soil. Each of them obtained 111 clones and 108 clones from Pine and Quercus forest soil. Thirty different RFLP types were detected from Pine forest soil and twenty-six different RFLP types were detected from Quercus forest soil by HeaIII. From ARDRA groups, dominant clones were selected for determining their phylogenetic characteristics based on 16S rDNA sequence. Based on the 16S rDNA sequences, dominant clones from ARDRA groups of Pine forest soil were classified into 7 major phylogenetic groups ${\alpha}$-proteobacteria (12 clones), ${\gamma}$-proteobacteria (3 clones), ${\delta}$-proteobacteria (1 clone), Flexibacter/Cytophaga (1 clone), Actinobacteria (4 clones), Acidobacteria (4 clones), Planctomycetes (5 clones). Also, dominant clones from ARDRA groups of Quercus forest soil were classified into 6 major phylogenetic groups : ${\alpha}$-proteobacte,ia (4clones), ${\gamma}$-proteobacteria (2 clones), Actinobacteria (10 clones), Acidobacteria (8 clones), Planctomycetes (1 clone), and Verrucomicobia (1 clone). Result of phylogeneric analysis of microbial community from Pine and Quercus forest soils were mostly confirmed at uncultured or unidentified bacteria, VBNC bacteria of over 99% existent in forest soil were confirmed variable composition of unknown micro-organism.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1031-1034
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• 2009

Fluorescence of quinolones including norfloxacin, ciprofloxacin and S- and R-ofloxacin is quenched upon association with single and double-stranded DNA (ss- and ds-DNA). The ratios of fluorescence intensity in the presence of DNA to its absent were plotted with respect to the DNA concentration to construct the Stern-Volmer plot. The slope of the Stern-Volmer plot become larger as the temperature is lowered, ensuring that the fluorescence quenching is static process, i.e., the fluorescence is quenched by formation of the non-fluorescent complex between quinolone and DNA. In the static quenching mechanism, the quenching constant which is equivalent to the slope of the Stern-Volmer plot, is considered as the equilibrium constant for the association of quinolones and DNA. From the temperature-dependent equilibrium constant, ${\Delta}H^0\;and\;{\Delta}S^0$ was obtained using the van’t Hoff relation. In general, association of the quinolone with ds- as well as ss-DNA is energetically favorable (an exothermic) process while the entropy change was unfavorable. Due to the steric effect of the substituents, the effect of the quinolone ring is smaller on the ss-DNA compared to ds-DNA.