• Journal of Life Science
• /
• v.24 no.4
• /
• pp.361-369
• /
• 2014

Broad-range and specific 16S rRNA gene PCR is used for detection and identification of bacterial pathogens in clinical specimens from patients with a high suspicion for infection. We describe the development of a broad-range and specific PCR primer, based on bacterial 16S rRNA, for use in routine diagnostic clinical microbiology services. The primers were designed by using conservative regions of 16S rRNA sequences from 10 strains. Ninety-eight clinical strains were isolated from clinical patient specimens. A total of 98 strains of bacteria were identified by phenotypic methods; PCR with newly designed primers and universal primers. All purified PCR products were sequenced using both forward and reverse primers on an automated DNA analyzer. In this study, we evaluated the usefulness of the newly designed primers and the universal primers for the detection of bacteria, and both these techniques were compared with phenotypic methods for bacteria detection. When we also tested 98 strains of clinical isolates with newly designed primers, about 778 bp DNA fragments were amplified and identified from all strains. Of the 98 strains, 94 strains (95.9%) correspond in comparison with phenotypic methods. The newly designed primers showed that the identities of 98 (100%) strains were the same as those obtained by universal PCR primers. The overall agreement between the newly designed primers and universal primers was 100%. The primer set was designed for rapid, accurate, and cheap identification of bacterial pathogens. We think the newly designed primer set is useful for the identification of pathogenic bacteria.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.1
• /
• pp.10-14
• /
• 2020

Pagurus is the most diverse hermit crab genus in Korea. In this study, the cytochrome c oxidase subunit I (COI) and 16S rRNA of 24 individuals from four Korean Pagurus species (i.e., 7 Pagurus brachiomastus, 8 P. proximus, 8 P. simulans, and 1 P. rectidactylus) were sequenced and analyzed. No genetic difference was found between the COI and 16S rRNA sequences of P. brachiomastus and P. simulans, and the COI sequences of P. rectidactylus and P. quinquelineatus (comparative species from NCBI). Considering the morphological and ecological characteristics together, we assume that P. simulans and P. rectidactylus are subspecies of P. brachiomastus and P. quinquelineatus, respectively. This study should facilitate further research on the taxonomic status of these species.

• Journal of Life Science
• /
• v.22 no.2
• /
• pp.167-176
• /
• 2012

Three protease-producing halophilic bacteria were isolated from fermenting anchovy. Isolated FAM 10, FAM 114, and FAM 115 were found to grow optimally at salt concentrations of 2-4%, 10%, and 6%, respectively, and could grow in salinity of up to 18-22%. The salinity conditions for optimum protease production were 6% in FAM 10 and 10% in FAM 114 and FAM 115. The protease activity of FAM 10 was gradually inhibited by the addition of NaCl up to 10%, and was not evident at 14%, whereas FAM 114 and FAM 115 displayed protease activity at 14% NaCl and could not be measured at 18%. These results demonstrated that the three isolated strains belong to protease-producing, moderately halophilic bacteria. Strain FAM 10, FAM 114, and FAM 115 were identified as Salinivibrio sp., Halobacillus sp., and Halobacillus sp. respectively, based on comparative analyses of the 16S rRNA gene and the 16S-23S intergenic space sequence (IGS), biochemical testing, and Gram staining. Salinivibrio sp. FAM 10 had two 16S rDNAs containing different sequences at position 191 and four IGSs that harbored no tRNA gene and tRNA genes for isoleucine, alanine, glutamate, lysine, and/or valine. Halobacillus sp. FAM 114 and FAM 115 had completely identical 16S rRNA gene sequences and showed 99% identity to the sequences of various Halobacillus strains. The three IGSs found in the genome of both strains displayed 99% sequence identity with Halobacillus aidingensis and Halobacillus sp. JM-Hb, and had $IGS^0$ with no tRNA gene and $IGS^{IA}$ with tRNA genes for isoleucine and alanine.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.3
• /
• pp.268-273
• /
• 2020

A spionid polychaete, Boccardiella hamata (Webster, 1879) has been found from mud in crevices between the shells of oysters and adherent substrates in South Korea. The sequences of mitochondrial DNA (mtDNA) cytochrome c oxidase subunit 1 (CO1), 16S ribosomal DNA (16S), and the nuclear 18S ribosomal DNA (18S) from Korean individuals of Boccardiella hamata were determined in the present study. The molecular analysis based on the 18S rRNA gene sequences showed clear separation among the spionid polychaete species, and the sequences of Korean and Japanese individuals are completely identical. The morphological diagnosis and photographs of B. hamata are also provided.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.1
• /
• pp.205-211
• /
• 2004

A 16S rDNA clone library was generated to investigate the bacterial diversity in tidal flat sediment in Ganghwa Island, Republic of Korea. A total of 103 clones were sequenced and analyzed by comprehensive phylogenetic analyses. No clones were identical to any of known 16S rRNA sequences in public databases. Sequenced clones fell into thirteen lineages of the domain Bacteria: the alpha, beta, gamma, delta, and epsilon Proteobacteria, Actinobacteria, CFB group, Chloroflexi, Acidobacteria, Planctomycetes, Verrucomicrobia, and known uncultured candidate divisions (OP11, BRC1, KSB1, and WS1). Two clones were not associated with any known bacterial divisions. The majority of clones belonged to the gamma and delta Proteobacteria (46.7%). Clones of Actinobacteria were distantly related to known taxa. It is evident from 16S rDNA-based community analysis that the bacterial community in tidal flat sediment is remarkably diverse and unique among other marine environments examined so far.

• Journal of the Korean Applied Science and Technology
• /
• v.40 no.4
• /
• pp.881-889
• /
• 2023

The genus Hymenobacter, type genus of the family Hymenobacteraceae and a member of the phylum Bacteroidota includes gram-negative and red-pigmented rods. Those bacteria have been isolated from various environments of the earth. I isolated a red-pigmented, gram-negative rod from a pond in the campus of the Changwon University, Changwon, Kyeongnam and designated this bacterium as strain B2. Strain B2 was further analyzed phylogenetically and biochemically, and concluded as a member of genus Hymenobacter. BLAST search of the 16S rRNA gene sequence of strain B2 showed its homology lower than 98.7% with those sequences of the other bacteria whose 16S rRNA gene sequences have been reported. Fatty acid composition of the strain B2 was analyzed and its major fatty acids are summed feature 3(C_16:1 ω7c and/or C_16:1 ω6c, 22.8%), iso-C_15:0 (16.2%), anteiso-C_15:0(12.9%), C_16:1ω5c(12.4%) and summed feature 4 (iso-C_17:1 I/anteiso-C_17:1)(9.5%) showing significant differences in fatty acid compositions between strain B2 and the other known Hymenobacter species. DNA sequence of 16S rRNA gene of strain B2 was deposited in genbank under accession number OQ318247.

• International Journal of Oral Biology
• /
• v.45 no.2
• /
• pp.70-75
• /
• 2020

The aim of this study was to identify strain KCOM 1265 isolated from subgingival plaque at the species level by comparing 16S ribosomal RNA gene (16S rDNA) and genome sequences. The whole genome of strain KCOM 1265 was extracted using the phenol-chloroform extraction method. 16S rDNA was amplified using polymerase chain reaction and sequenced using the dideoxy chain termination method. Pairwise genome comparison was performed using average nucleotide identity (ANI) and genome-to-genome distance (GGD) analyses. The data showed that the percent similarity of 16S rDNA sequence of strain KCOM 1265 was 99.6% as compared with those of Fusobacterium polymorphum ATCC 10953^T and Fusobacterium hwasookii KCOM 1249^T. The ANI values of strain KCOM 1265 with F. polymorphum ATCC 10953^T and F. hwasookii KCOM 1249^T were 95.8% and 93.0%, respectively. The GGD values of strain KCOM 1265 with F. polymorphum ATCC 10953^T and F. hwasookii KCOM 1249^T were 63.9% and 49.6%, respectively. These results indicate that strain KCOM 1265 belongs to F. polymorphum.

• Microbiology and Biotechnology Letters
• /
• v.38 no.3
• /
• pp.322-328
• /
• 2010

Fermented skate is a traditional Korean food popular in Southwestern area of Korea. It has a characteristic flavor and alkaline pH. In this study we tried to determine the microbial flora in fermented skate using two different approaches. In culture-independent method, we amplified V2 region of 16S rRNA gene by PCR and cloned them into pUC18 plasmid to construct 16S rDNA fragment library. BLAST searches for the sequences obtained from this library revealed that uncultured bacterium clone 054E11.b was the most dominant flora in this fermented fish. In culture-dependent method, we diluted suspension of skate and spreaded on MRS, PCA, and MacConkey plates. We identified colonies grown on those plates by using PCR amplification of V2 region of 16S rRNA and DNA sequencing. BLAST searches of those DNA sequences resulted in totally different species with the observations from the 16S rDNA library analysis. Discrepancies of results obtained from both approaches suggest that the agar plates used in culture-dependent method may be different from the real condition of fermented skate. Therefore, results from culture-independent approach using 16S rDNA fragment library analysis may reflect real microbial flora in fermented skate.

• Korean journal of applied entomology
• /
• v.39 no.4
• /
• pp.211-226
• /
• 2000

Genetic divergence and phylogenetic relationships among the major Korean fireflies (Hotaria papariensis, Luciola lateralis, and Pyrocoelia rufa) were studied. A portion of mitochondrial COI (403 bp) and 165 rRNA (490~504 bp) genes were sequenced, and the GenBank-registered, homologous 165 rRNA sequences of Japanese fireflies were compared (27 species of Lampyridae, one of Lycidae, and one of Rhgophthalmidae). Greatest DNA and/or amino acid sequence divergence was found when P rufa, belonging to Lampyrinae was compared with H. papariensis and L. lateralis, both belong-ing to Luciolinae, confirming the current taxonomic status of the species. In the PAUP and PHYLIP analyses with 165 rRNA data, grouping of the two geographic samples of H. papariensis with H. tsushimana validate the use of generic name, Hotaria. Nevertheless, lack of sister-group relationship of the two geographic samples of H. papariensis renders further investigation on this group . Although the Korean and Japanese L. lateralis formed a strong monophyletic group, a substantial genetic differentiation was detected between them (2.9% of 165 rRNA gene sequence divergence). Finally, the geographic samples of Korean p. rufa strongly formed a group with Japanese p. rufa, warranting the use of generic name, Pyrocoelia, but the genetic distance observed between the Cheju-Island individual and all others requires further investigation on this subject. Summarized, this study supports the current taxonomic status of the Korean fireflies in that each respectively formed a strong monophyletic group with its own species or genus.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.1
• /
• pp.21-29
• /
• 2010

The phenolic compounds are a major contaminant class often found in industrial wastewaters and the biological treatment is an alternative tool commonly employed for their removal. In this sense, monitoring microbial community dynamics is crucial for a successful wastewater treatment. This work aimed to monitor the structure and activity of the bacterial community during the operation of a laboratory-scale continuous submerged membrane bioreactor (SMBR), using PCR and RT-PCR followed by denaturing gradient gel electrophoresis (DGGE) and 16S rRNA libraries. Multivariate analyses carried out using DGGE profiles showed significant changes in the total and metabolically active dominant community members during the 4-week treatment period, explained mainly by phenol and ammonium input. Gene libraries were assembled using 16S rDNA and 16S rRNA PCR products from the fourth week of treatment. Sequencing and phylogenetic analyses of clones from the 16S rDNA library revealed a high diversity of taxa for the total bacterial community, with predominance of Thauera genus (ca. 50%). On the other hand, a lower diversity was found for metabolically active bacteria, which were mostly represented by members of Betaproteobacteria (Thauera and Comamonas), suggesting that these groups have a relevant role in the phenol degradation during the final phase of the SMBR operation.