• The Korean Journal of Ecology
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• v.26 no.6
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• pp.307-312
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• 2003

To study the diversity of heterotrophic bacteria isolated from intestine of starfish, Asterias amurensis, we collected starfishes from the coastal area near Jangheung-Gun, Jeollanam-Do, Korea during July, 2000. Population density and bacterial diversity in the intestine of starfish were measured. The results were as follows; The population densities of heterotrophic bacteria in the intestine of starfish were 8.65${\pm}$0.65${\times}10^3\;dfu\;g^{-1}$. Gram positive bacteria occupied 59% among 29 isolates. The community structure of dominant heterotrophic bacteria in the intestine of starfish consisted of Bacillaceae in the low G+C gram positive bacteria subphylum, Microbacteriaceae in the high G+C gram positive bacteria subphylum, and Alteromonadaceae in ${\gamma}$-Proteobacteria subphylum. Among eight strains of Bacillus spp., three strains showed more than 97% identity, but five strains showed about 90% identity with type strain on the basis of partial 16S rDNA sequence.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.117-124
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• 2005

Two bacterial isolates obtained from rotifer and diseased olive flounder larvae, Paralichthys olivaceus, were identified as Vibrio ichthyoenteri based on the results of phenotypic characterization. In an attempt to develop rapid PCR method for the detection of V. ichthyoenteri, we examined the 16S-23S rRNA intergenic spacer region(ISR) of V. ichthyoenteri and developed species-specific primer for V. ichthyoenteri. Analysis of the ISR sequences showed that V. ichthyoenteri contains one type of polymorphic ISRs. The size of ISRs was 348 bp length and did not contain tRNA genes. Mutiple alignment of representative sequences from different V. species revealed several domains of high sequence variability, and allowed to design species-specific primer for detection of V. ichthyoenteri. The specificity of the primer was examined using genomic DNA prepared from 19 different V. species, isolated 18group Vibrio species and most similar sequence of other known Vibrio species. The results showed that the PCR reaction using species-specific primer designed in this study can be used to detect V. ichthyoenteri.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.36-39
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• 2014

Many bacteria colonized in the horse semen affect quality of the sperm and some may cause infection in the mare reproductive tract and infertility of susceptible mare. This study was initiated to determine the prevalence of bacteria in testes of Jeju horses by determining rRNA sequence. The samples were swabed from the testes of nine Jeju horses (aged from 8 to 12 months after birth). Bacteria isolated from testes were identified by 16S rDNA sequencing. 1.6-kbp PCR products for 16S rRNA coding region were obtained using the universal primers. The PCR products were further purified and sequenced. Maximum similar species were found by BLAST search in the GenBank DNA database. BLAST results showed that the sequences were similar to those of Acinetobacter sp (A. schindleri, A. ursingii)., Bacillus cereus, Corynebacterium glutamicum, Escherichia coli, Gamma proteobacterium, Micrococcus luteus, Pseudomonas mendocina, Shigella sonnei, Sphingomonas sp., Staphylococcus sp (S. cohnii, S. saprophyticus, S. xylosus)., and Stenotrophomonas maltophilia. DNA sequences for 16S rRNA is provided useful informations for species identification of pathogenic microorganisms for the reproductive organs in horses.

• Journal of Microbiology
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• v.41 no.4
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• pp.312-319
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• 2003

In an attempt to develop a method for rapid and accurate identification of six Vibrio species that are clinically important and most frequently detected in Korea, 16S rDNA restriction fragment length polymorphism (RFLP) of Vibrio type strains, as well as environmental isolates obtained from the Korean coastal area, was analyzed using ten restriction endonucleases. Digestion of the 16S rDNA fragments amplified by polymerase chain reaction (PCR) with the enzymes gave rise to 2~6 restriction patterns for each digestion for 47 Vibrio strains and isolates. An additional 2~3 restriction patterns were observed for five reference species, including Escherichia coli, Aeromonas hydrophila, A. salmonicida, Photobacterium phosphoreum, and Plesiomonas shigelloides. A genetic distance tree based on RFLP of the bacterial species correlated well with that based on 16S rDNA sequences. The very small 16S rDNA sequence difference (0.1%) between V. alginolyticus and V. parahaemolyticus was resolved clearly by RFLP with a genetic distance of more than 2%. RFLP variation within a species was also detected in the cases of V. parahaemolyticus, V. proteolyticus, and V. vulnificus. According to the RFLP analysis, six Vibrio and five reference species were assigned to 12 genotypes. Using three restriction endonucleases to analyze RFLP proved sufficient to identify the six pathogenic Vibrio species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.356-361
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• 2007

Recently, the development of various culture-independent identification techniques for environmental microbes has greatly enhanced our knowledge of microbial diversity. In particular, denaturing gradient gel electrophoresis (DGGE) of 16S rDNA fragments, generated using the polymerase chain reaction (PCR) is frequently used to examine the diversity of environmental bacterial populations. This method consists of direct extraction of the environmental DNA, amplification of the 200-600 bp 16S rDNA fragments with universal primers, and separation of the fragments according to their melting point on a denaturing gradient gel. In this study, we investigated the seaside microbial community in coastal areas of Busan, Korea, using culture-independent techniques. First, marine genomic DNA was extracted from seawater samples collected at Songjeong, Gwangahn, and Songdo Beaches. Then, PCR was used to amplify the bacterial 16S rDNA using universal primers, and DGGE was used to separate the amplified 500 bp 16S rDNA fragments. Finally, the tested 16S rDNA genes were further analyzed by sequencing. Based on these experiments, we found that DGGE analysis clearly showed variation among the regional groups. It can be used to monitor rapid changes in the bacterial diversity of various environments. In addition, the sequence analysis indicated the existence of many unculturable bacteria, in addition to Arcobacter, Pseudoaltermonas, and Vibrio species.

• International Journal of Oral Biology
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• v.41 no.4
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• pp.199-208
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• 2016

The aim of this study was to identify the non-Aggregatibacter actinomycetemcomitans bacteria grown on the tryptic soy-serum-bacitracin-vancomycin (TSBV) medium, an A. actinomycetemcomitans selective medium. A total of 82 unidentified bacterial isolates from the oral cavities of a Korean population were kindly provide by the Korean Collection for Oral Microbiology. All the clinical isolates were grown on TSBV medium and bacterial DNA purified from each isolate was subjected to PCR with universal primers specific for bacterial 16S rRNA genes (16S rDNAs) sequence. The each bacterial 16S rDNA was amplified by PCR and the nucleotide sequences of it was determined by the dideoxynucleotide chain termination method. They were identified by 16S rDNA sequence comparison method at the specie-level. The data showed that Neisseria spp. (42 strains), Fusobacterium spp. (10 strains), Capnocytophaga spp. (8 strains), Propionibacterium acnes (5 strains), Aggregatibacter aprophilus (4 strains), Campylobacter spp. (5 strains), Veillonella dispar (3 strains), Streptococcus sp. (1 strain), Haemophilus parainfluenzae (1 strain), Leptotrichia wadei (1 strain), Morococcus sp./Neisseria sp. (1 strain), and Staphylococcus sp. (1 strain) were identified. These results could be used to develop a new A. actinomycetemcomitans-selective medium which is more effective than the TSBV medium in future studies.

• 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.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.109-114
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• 2002

To evaluate the phylogenetic and taxonomic status of the phytoplasmas associated with water dropwort (Oenanthe javanica DC) disease in Korea and Japan, their 16S rDNA was analyzed. DNAs extracted from water dropworts collected in Korea (Kyongnam province) and Japan (Chiba prefecture) affected by witches' broom and yellows were subjected to PCR using phytoplasma-specific primers, which amplified a 1.4-kbp fragment that included the 16S rDNA. Phytoplasmas were characterized by RFLP analysis using AluI, HaeIII, HhaI, KpnI, MseI, and RsaI restriction enzymes and by sequence analysis of the PCR products. The mater dropwort witches'broom (WDWB) and water dropwort yellows (WDY) 16S rDNA sequences were identical and closely related to onion yellows (OY, 99.9% identity), which belong to the aster yellows (AY) 16S-subgroup. However, the KpnI RFLP analyses clearly distinguished the WDY and WDWB phytoplasmas from the OY phytoplasma. The phylogenetic analysis based on 16S rDNA showed that WDWE and WDY phytoplasmas are members of a relatively homogeneous group that evolved from a common ancestor.

• Korean Journal of Microbiology
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• v.35 no.2
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• pp.121-127
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• 1999

An effective computer program for assembling fragments in DNA sequencing has been developed. The program, called SeqEditor (Sequence Editor), is usable on the pcrsonal computer systems of MS-Widows which is the mosl popular operating system in Korea. It c'm recd several sequence file formats such as GenBak, FASTA, and ASCII. In the SeqEditor program, a dynamic programming algorihm is applied to compute the maximalscoring overlapping alignment between each pjlr of fragments. A novel feature of the program is that SeqEdilor implemnents interaclive operation with a graphical user interface. The performance lests of the prograln 011 fragmen1 data from 16s and 18s rDNA sequencing pi-ojects produced saiisIactory results. This program may be useful to a person who has work of time with large-scale DNA sequencing projects.

• 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.