• Korean Journal of Microbiology
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• v.41 no.2
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• pp.125-128
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• 2005

A 16S ribosomal RNA gene from S. chungbukensis DJ77 has been sequenced. This sequence had a length of 1,502 bp and was extended for 29 bp at 5' and for 37 bp at 3' from the partial sequence (1,435 bp) registered in 2000 year. Besides, 1 bp was newly added near to the 3' end. We made the secondary structure of the 16S rRNA based on E. coli model and found four specific regions. We found constant and variable regions in genus Sphingomonas as the result of multiple alignment of 16S rRNA gene sequences from Sphingomonas spp. and S. chungbukensis DJ77. We found a stem loop structure in S. chungbukensis DJ77, which was only discovered in C. jejuni to date. It showed the structural agreement despite the difference of the sequences from the both organisms. Finally, S. chungbukensis DJ77 belonged to cluster II (Sphingobium) group, after the classification using phylogenetic analysis and nucleotide signature analysis.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.498-505
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• 2011

Objectives: The purpose of this in vivo study was to investigate the microbial diversity in symptomatic and asymptomatic canals with primary endodontic infections by using GS FLX Titanium pyrosequencing. Materials and Methods: Sequencing was performed on 6 teeth (symptomatic, n = 3; asymptomatic, n = 3) with primary endodontic infections. Amplicons from hypervariable region of the small-subunit ribosomal RNA gene were generated by polymerized chain reaction (PCR), and sequenced by means of the GS FLX Titanium pyrosequencing. Results: On average, 10,639 and 45,455 16S rRNA sequences for asymptomatic and symptomatic teeth were obtained, respectively. Based on Ribosomal Database Project Classifier analysis, pyrosequencing identified the 141 bacterial genera in 13 phyla. The vast majority of sequences belonged to one of the seven phyla: Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, Proteobacteria, Spirochetes, and Synergistetes. In genus level, Pyramidobacter, Streptococcus, and Leptotrichia constituted about 50% of microbial profile in asymptomatic teeth, whereas Neisseria, Propionibacterium, and Tessaracoccus were frequently found in symptomatic teeth (69%). Grouping the sequences in operational taxonomic units (3%) yielded 450 and 1,997 species level phylotypes in asymptomatic and symptomatic teeth, respectively. The total bacteria counts were significantly higher in symptomatic teeth than that of asymptomatic teeth (p < 0.05). Conclusions: GS FLX Titanium pyrosequencing could reveal a previously unidentified high bacterial diversity in primary endodontic infections.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.479-485
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• 2005

The 994 throat swabs obtained from 688 adults and 306 children patients with respiratory diseases were examined for Mycoplasma pneumoniae infection by culture method. Antimicrobial susceptibilities of the resulting 123 M. pneumoniae isolates were evaluated by testing minimum inhibitory concentrations (MICs) of erythromycin, minocycline, tetracycline, josamycin, sparfloxacin, ofloxacin, and ciprofloxacin by a broth micro-dilution method. The erythromycin resistant strains of M. pneumoniae was determined above $1.0{\mu}g/ml$ of MIC for erythromycin. The erythromycin resistant strains of M. pneumoniae was confirmed resistant gene mutation of the portions of genes 23S rRNA (domain II and V), and ribosomal protein 14 and L22 by PCR amplified and their nucleotide sequenses were compared to those of the susceptible strain M129. The isolation rate of M. pneumoniae was $12.9\%$ (89/688) for the adults and $11.1\%$ (34/306) for the children. The $MICs_{90}$ of the M. pneumoniae isolates were $0.12{\mu}g/ml$ for minocycline, $0.25{\mu}g/ml$ for sparfloxacin, $0.5{\mu}g/ml$ for ciprofloxacin, ofloxacin, and tetracycline, respectively, and $2.0{\mu}g/ml$ for josamycin and erythromycin, respectively. The isolation rate of erythromycin resistant M. pneumoniae from patients was $49.4\%\;(44/89)$ for the adults, $47.1\%\;(16/34)$ for children, and $48.8\%\;(60/123)$ for the total. No mutation could be detected in the ribosomal protein L22 region, but all strains were mutated in the ribosomal protein L4 as two point mutation M144V. Two point mutations in domain V of 23S rRNA were selected in the presense of erythromycin resistant M. pneumoniae isolates, such as one strain was G2057C mutant, two strains were A2059C mutants, three strains were C2611G mutants, four strains were A2058C mutants, five strains were A2058T mutants, twenty strains were A2059G mutants, and twenty-five strains were A2058G mutants, respectively. These results show that erythromycin was not the most active compound against M. pneumoniae infection in Korea and clinical studies of macrolides in human patients are demanded.

• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.350-357
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• 1998

A total of 12 strains of fluorescent Pseudomonas isolated from the cultivated mushrooms such as Agaricus bisporus and Pleurotus ostreatus were collected. They consisted of pathogenic Pseudomonas spp. and epiphytic Pseudomonas spp. of the cultivated mushroom. To analyze the phylogenetic relationship of these strains, ITS I region, the 16S-23S intergenic spacer region in the ribosomal RNA (rRNA) operon, was cloned and sequenced. The spacer regions of these strains were 495∼527 nucleotides in length and contained the genes encoding isoleucine-tRNA (tRNAIle) and alanine-tRNA (tRNAAla). The reciprocal homologies of each ITS I sequence among these strains were in the range of 84.2%∼98.8%. According to the analysis of ITS I sequences, the fluorescent Pseudomonas spp. were phylogenetically classified into three clusters. Cluster I consisted of Pseudomonas fluorescens, P. tolaasii, P. gingeri’, and P.‘reactans’(WLRO). Cluster II comprised Pseudomonas fluorescens biovar C and F. Cluster III composed P. agarici. Cluster I and II could be classified into P. fluorescens complex. P. agarici formed an independent taxon clearly separable from P. florescens complex.

• Journal of Species Research
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• v.9 no.4
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• pp.339-345
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• 2020

The Earth contains billions of microbial species, although the vast majority cannot be cultured in laboratories and are thus considered unidentified and uncharacterized. Extremophiles are microorganisms that thrive in extreme conditions, including temperature, salinity, and pH. Extremophilic microorganisms have provided important insights for biological, metabolic, and evolutionary studies. Between 2017 and 2019, as part of a comprehensive investigation to identify bacterial species in Korea, eight bacterial strains were isolated from marine and non-marine environments in Jeju Island. These strains were cultured under extreme salinity or pH conditions. Phylogenetic analysis using 16S ribosomal RNA(rRNA) gene sequencing indicated that all eight strains belonged to the phyla Gammaproteobacteria, Bacilli, and Alphaproteobacteria. Based on their high 16S rRNA gene sequence similarities(>98.7%) and the formation of strong monophyletic clades with their closest related species, all isolated strains were considered as an unrecorded strain, previously unidentified species. Gram stain reaction, culture conditions, colony and cell morphology, biochemical characteristics, isolation source, and National Institute of Biological Resources(NIBR) IDs are described in this article. The characterization of these unrecorded strains provides information on microorganisms living in Korea.

• KSBB Journal
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• v.26 no.2
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• pp.131-138
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• 2011

Some computational approaches are needed for clarifying RNAi sequences, because it takes much time and endeavor that almost of RNAi sequences are verified by experimental data. Incorrectness of RNAi mechanism and other unaware factors in organism system are frequently faced with questions regarding potential use of RNAi as therapeutic applications. Our massive parallelized pair alignment scoring between dsRNA in Genebank and expressed sequence tags (ESTs) in Caenorhabditis elegans Genome Sequencing Projects revealed that this provides a useful tool for the prediction of RNAi induced cosuppression details for practical use. This pair alignment scoring method using high performance computing exhibited some possibility that numerous unwanted gene silencing and cosuppression exist even at high matching scores each other. The classifying the relative higher matching score of them based on GO (Gene Ontology) system could present mapping dsRNA of C. elegans and functional roles in an applied system. Our prediction also exhibited that more than 78% of the predicted co-suppressible genes are located in the ribosomal spot of C. elegans.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.280-282
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• 2018

Pseudoalteromonas sp. meg-B1 belonging to Gammaproteobacteria was isolated from marine sediment in Jeju island. Here, we report the draft genome sequence of strain meg-B1 with a size of approximately 4.15 Mbp and a mean G + C content of 41.2%. The draft genome included 3,606 coding sequences, and 9 ribosomal RNA and 94 transfer RNA genes. In the draft genome, genes (e.g. choline dehydrogenase) involved in the accumulation of compatible solutes required for survival in marine environments have been identified.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.326-328
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• 2017

Herbaspirillum sp. meg3 belonging to Betaproteobacteria was isolated from soil in Jeju island. Here, we report the complete genome sequence of strain meg3 with a size of approximately 5.47 Mb and a mean G + C content of 57.1%. The genome included 4,816 coding sequences, and 9 ribosomal RNA and 51 transfer RNA genes. In the genome, two incomplete prophage regions have been identified. Also, we propose that strain meg3 has a potential capability for aromatic-compounds degradation based on the result of genome analysis.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.61-63
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• 2019

Streptococcus sp. strain NM belonging to Firmicutes was isolated from head and neck cancer patients. Here, we report the draft genome sequence of strain NM with a size of approximately 1.90 Mbp and a mean G+C content of 39.3%. The draft genome included 1,845 coding sequences, and 12 ribosomal RNA and 58 transfer RNA genes. In the draft genome, genes involved in the antimicrobial resistance, hemolysis and defense system have been identified.

• Korean Journal of Plant Taxonomy
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• v.52 no.2
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• pp.114-117
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• 2022

Lindera angustifolia is mainly distributed in the temperate climate zone of China but shows an extraordinary distribution, disjunctively isolated on the western coastal islands of Korea. We therefore present the complete chloroplast genome of Korean L. angustifolia. The complete plastome was 152,836 bp in length, with an overall GC content of 39.2%. A large single copy (93,726 bp) and a small single copy (18,946 bp) of the genome were separated by a pair of inverted repeats (20,082 bp). The genome consists of 125 genes, including 81 protein-coding, eight ribosomal RNA, and 36 transfer RNA genes. While five RNA editing genes (psbL, rpl2, ndhB×2, and ndhD) were identified in L. angustifolia from China, the "ndhD" gene was not recognized as an RNA editing site in the corresponding Korean individual. A phylogenetic analysis revealed that Korean L. angustifolia is most closely related to the Chinese L. angustifolia with strong bootstrap support, forming a sister group of L. glauca.