• Mycobiology
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• v.34 no.3
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• pp.154-157
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• 2006

A fungal isolate collected from infected paprika (Capsicum annuum var. grossum) was characterized as Sclerotinia sclerotiorum based on its ability of sclerotium formation, physiological and molecular properties. When the isolate was grown on potato dextrose agar, oatmeal agar, and malt extract agar, it grew most well on PDA. Optimal temperature and pH for its growth were $25^{\circ}C$ and pH 7, respectively. The fungal isolate produced sclerotia on PDA within 10 days, and the color and shape of the sclerotia were similar to those of S. sclerotiorum. The ITS rDNA regions including ITS1 and ITS2 and 5.8S sequences were amplified using ITS1F and ITS4 primers from the genomic DNAs of the paprika isolate and other known pathogenic S. sclerotiorum isolated from different crops in Korea, and their nucleotide sequences were determined. Sequence comparison analysis showed the ITS rDNA of the paprika isolate shares 100% sequence identity with those of S. sclerotiorum isolated from red pepper, lettuce and a S. sclerotiorum isolate registered in GenBank DNA database. Neighbor joining analysis based on the ITS rDNA sequence revealed the paprika isolate has very close phylogenetic relationships with known Sclerotinia sclerotiorum isolates. This is the first report that S. sclerotiorum has been found associated with paprika rot in paprika growing countries.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.19-25
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• 2006

This study was undertaken to develop PCR primers for the identification and detection of Streptococcus mutans (by)using species-specific forward and universal reverse primers. These primers targeted the variable regions of the 16S ribosomal RNA coding gene (rDNA). The primer specificity was tested against 11S. mutans strains and 10 different species (22 strains) of oral bacteria. The primer sensitivity was determined by testing serial dilutions of the purified genomic DNA of S. mutans ATCC $25175^T$. The data showed that species-specific amplicons were obtained from all the S. mutans strains tested, which was not observed in the other species. The direct and nested PCR could detect as little as 2 pg and 2 fg of the chromosomal DNA from S. mutans ATCC $25175^T$, respectively. This shows that the PCR primers are highly sensitive and applicable to the detection and identification of S. mutans.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1698-1705
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• 2020

Bacteria were collected from the thumb surface of the twenty young adults that are 20 to 25 years old and cultured on the Luria-Bertani agar. The 16S rDNA of the cultured bacteria was amplified by polymerase chain reaction(PCR) and DNA sequence of the PCR products analyzed. Total 14 different bacterial species were identified by comparing their 16S rDNA sequence with the data in genbank. It appears that each individual has 2.5 different bacterial species in average. Staphylococcal species were the most abundant among the identified bacteria and Micrococcus luteus was the second. Staphylococcal species were isolated at similar frequency between male and female donors but Micrococcus luteus was isolated more frequently from female than male donors. The result obtained in this study might be useful in research of dermatic diseases, searching for new drugs for those diseases and development of new cosmetics.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.191-196
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• 2003

This study was carried out to investigate the isolation, identification, and antibacterial activity of lactic acid bacteria related to kimchi fermentation. Diluted kimchi soup was plated on the MRS agar media with CaCO$_3$ and incubated at $25^{\circ}C$ for 2 days. A total of 27 strains of lactic acid bacteria from various indigenous, spontaneously fermented vegetables (kimchi) were isolated. Combined methods of Bergey's manual of systematic bacteriology, BPB media analysis and 16S rDNA sequence analysis were applied for identification, however, their results did not coincide in several cases. Isolated lactic acid bacteria could be classified by the 16S rDNA sequence analysis as Leuconostoc mesenteriodes, Leu. carnosum, Lactobacillus curvatus, Lac. pentosus, Weisselia kimchi, W. cibaria, and Pediococcus pentosaceus. Leu. carnosum has not been reported in kimchi lactic acid bacteria. In addition, antibacterial activities of the isolates were tested with Bacillus subtilis, Escherichia coli, Salmonella enteritidis, S. paratyphica, S. typhi, Staphylococcus aureus, Shigella boydii, and S. sonnei. Some of isolates showed significant antibacterial activities to those pathogens.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.13-25
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• 1999

P. endodontalis which was known to be associated with the infected root canals and periapical lesions is very difficult to detect by culture methods or traditional methods. Detection of bacteria using polymerase chain reaction(PCR) for 16S ribosomal DNA(rDNA) is fast, simple, and accurate with relatively small amount of target cells. 16S rDNA consist of conserved regions those are same to all species, and variable regions which represent species specificity. The 16S rDNA sequences of P. endodontalis and P. gingivalis were aligned and two highly variable regions were selected as a pair of species specific oligonucleotide primers for P. endodontalis. And then the pair of primers for PCR amplification was synthesized to identify P. endodontalis. The sequences of the species specific primers for the 16S rDNA of P. endodontalis were as follows ; sense primer[endo1]: 5'-CTATATTCTTCTTTCTCCGCATGGAGGAGG-3' antisense primer[endo2]: 5'-GCATACCTTCGGTCTCCTCTAGCATAT-3' In this study, for the identification of P. endodontalis without culture from the mixed clinical samples, PCR was done with species specific primers for the 16S rDNA sequences of P. endodontalis. The results were as follows : 1. The species specificity of the primers for the 16S rDNA of P. endodntalis was determined by the PCR methods. About 490bp amplicon which was specific only for P. endodntalis was produced with P. endodontalis. No amplicon was produced by PCR with other strains similar to P. endodontalis. 2. The synthesized species specific primers reacted with conventionally identified P. endodontalis which we have in conservative dentistry laboratory. 3. The identification of P. endodontalis using PCR technique with samples collected from infected root canals or periapical lesions was more sensitive than that of culture methods. 4. Seven samples revealed including P. endodontalis by PCR technique. Five of them were related with pains, two of them with sinus tract, three of them with foul odor, and three of them with purulent drainage. P. endodontalis was shown to have great relation with pains.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.879-883
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• 2005

This study was differentiated between Korea and China arkshells using PCR-aided RFLP method which could identify the variation for inter-and intra-species of arkshell (Scapharca broughtonii Schrenck) at the level of DNA. The DNA fragment patterns were compared after digesting gene of mitochondrial 16S rDNA with 8 kinds of restriction enzymes. A 720 bp DNA fragment corresponding to 16S rDNA gene was amplified by PCR with primers ArkF-3 and ArkR-3. PCR products were cut by restriction enzymes (Pvull, BamHI, Hinfl, HaeIII, EcoRI, RsaI, Ksp221, and BstX21), and RFLP pattern was studied. A unique 275 bp DNA band was observed in the samples from Dukyang, Gamak, Namhae, Jinhae, and Taean in Korea when treated by Hinfl, but Chinese arkshell did not show. Treatment of HaeIII could discriminate the sample of Namhae and Jinhae from Dukyang/Gamak/Taean, as well as Korean and Chinese arkshell based on a 700 bp. However, PuvII, BamHI, EcoRI, RsaI, Ksp221, and BstX21 showed the same of 700 bp band in Korean and Chinese arkshell. The phylogenetic tree inferred from PCR-RFLP pattern comparsion in Korean arkshell was different that the distance between Dukyang/Gamak/Taean and Namhae/Jinhae was approximately 7. In particular, the distance between Korean and Chinese arkshell was 25. Consequently, HinfI and HaeIII played an important role in a reliable molecular tool for rapid discriminating Korean and Chinese arkshell, as well as a intra-species in Korea.

• Journal of Life Science
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• v.25 no.2
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• pp.243-248
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• 2015

Cirsium chanroenicum, Cirsium nipponicum, and Cirsium schantarense plants were collected from Changwon, Ulleungdo, and Dooryoon Mountain, respectively. Cirsium japonicum plants were also collected from various locations in Korea. Genomic DNA was prepared from the collected plants and used for amplification of the 18S rDNA, ITS1, 5.8S rDNA, ITS2, and part of 28S rDNA. The ITS1 and ITS2 sequences of the PCR products and from other Cirsium plants reported previously were aligned and compared. Cirsium chanroenicum, Cirsium nipponicum, and Cirsium setidens formed distinct branches on the neighbor-joining tree. Cirsium japonicum and Cirsium pendulum appeared to be close to one another, but Cirsium pendulum plants were clearly clustered in an independent clade. Cirsium shantarense was clustered with the other Cirsium japonicum plants. The most important characteristic that distinguished these two species was the direction of the flowers. All Cirsium japonicum flowers point upward, but Cirsium shantarense flowers point downward. Other than this feature, these two species are almost indistinguishable morphologically. Cirsium chanroenicum is indistinguishable morphologically from Cirsium setidens, but it still formed a distinct group on the neighbor-joining tree based on ITS sequences, suggesting that this species is worth considering as an independent species. Silymarin production of the collected plants was analyzed and appeared to be quite high, indicating that the ability to synthesize silymarin is common to all Cirsium plants analyzed so far.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.301-307
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• 2006

A ligniolytic bacterial strain was isolated from the digestive tract of a red dragonfly, Sympetrum dopressiusculum. It was identified as a Serratia marcescens HY-5 by 16S rDNA sequence analysis and physiological and biochemical analysis. The isolated strain showed proportional increase of ligninolytic activity to the cell growth in the culture media which include lignin compounds. It showed about 25-45% decomposition of lignin compound by 48 hr incubation especially, showed effective decomposition of monomer lignin compounds, vanillin and guaiacol, and a dimer, dealkaline lignin. PCR amplification of 16S rDNA followed by denaturing gradient gel electrophoresis analysis showed high density of S. marcescens HY-5 in the gut of the S. depressiusculum at both gut samples which collected at different site.

• Mycobiology
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• v.34 no.1
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• pp.7-13
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• 2006

Arbuscular mycorrhizas (AM) have mutualistic symbiosis with plants and thus efforts have been placed on application of these symbiotic relationships to agricultural and environmental fields. In this study, AM fungi were collected from 25 sites growing with 16 host plant species in Korea and cultured with Sorghum bicolor in greenhouse condition. AM fungal spores were extracted and identified using both morphological and molecular methods. Using morphological characters, total 15 morpho-speices were identified. DNA was extracted from single spore of AM fungi and a partial region on 18S rDNA was amplified using nested PCR with AM fungal specific primers AML1/AML2. A total of 36 18S rDNA sequences were analyzed for phylogenetic analysis and 15 groups of AM fungi were identified using both morphological and molecular data of spores. Among the species, 4 species, Archaeospora leptoticha, Scutellospora castanea, S. cerradensis, S. weresubiae were described for the first time in Korea and two species in Glomus and a species in Gigaspora were not identified. Morphological and molecular identification of AM fungal spores in this study would help identify AM fungal community colonizing roots.

• Korean Journal of Ichthyology
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• v.25 no.3
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• pp.149-156
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• 2013

Phylogenetic relationships and DNA polymorphism among local populations of two Korean gobiidae species: Boleophthalmus pectinirostris and Scartelaos gigas were investigated based on 12S and 16S mitochondrial DNA and mitochondrial cytochrome b DNA sequences. DNA polymorphisms of B. pectinirostris between Suncheon and Gunsan populations were 100% identity from 434 bp segment of 12S rRNA gene and from 444 bp segment of mitochondrial cytochrome b genes, and 99.6% (2 bp different) identity from 484 bp segments of 16S rRNA genes. These results indicated the long period of geographic isolation between two populations of B. pectinirostris in Korea caused such high degrees of DNA polymorphisms. Based on the phylogenetic tree constructed from the two gobiid species in Korea, two genetically distinct groups of B. pectinirostris and S. gigas groups were recognized.