• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.67-73
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• 1998

A bacterial strain that excretes hemolysins and proteases into the growth medium was isolated from sea water and designated as KYJ 961. A nearly complete nucleotide sequence of a 16S ribosomal RNA gene from the isolate was determined following the isolation and cloning of amplified genes. On the basis of the 16S ribosomal DNA sequence data, and morphological, chemotaxonomic, and physiological characteristics, strain KYJ 961 was classified as a strain of Bacillus cereus.

• Microbiology and Biotechnology Letters
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• 제31권4호
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• pp.429-434
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• 2003

The 16S rDNA sequences of nine strains, two type strains of validated Microbispora species and a strain of invalidated Microbispora species, and six soil isolates, were determined and compared with those of representatives of the family Streptosporangiaceae. The phylogenetic analysis indicated that all of the validated species of the genus Microbispora consistently formed a monophyletic unit and were well separated from the other genera of the family Streptosporangiaceae. All the isolates were placed to the genus Microbispora, whereas an invalidated Microbispora species, Microbispora griseoalba IMSNU $22049^{T}$ (= KCTC $9314^{T}$), was closely related to members of the genus Nocardia.

• Animal Systematics, Evolution and Diversity
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• 제36권3호
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• pp.268-273
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• 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.

• Microbiology and Biotechnology Letters
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• 제32권3호
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• pp.218-223
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• 2004

Myxobacteria are Gram-negative soil bacteria known to be a rich source of potentially useful secondary metabolites. We have isolated 204 strains of bacteriolytic myxobacteria from soil samples collected in Korea and determined their 16S rRNA sequences. Sequence analysis of the partially determined 16S rRNA sequences has suggested that 132 isolates (65% of total isolates) belong to the genus Myxococcus and 59 isolates (29% of total isolates) belong to the genus Corallococcus. Meanwhile, 4 isolates appear to be Archangium spp. and the other 4 isolates appear to be Stigmatella spp. Genera of the remained 5 isolates have not been identified because their 16S rRNA sequences are distantly related to those of known myxobacteria.

• Animal Bioscience
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• 제36권2_spc호
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• pp.364-373
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• 2023

The gastrointestinal (GI) tract of ruminants contains diverse microbes that ferment various feeds ingested by animals to produce various fermentation products, such as volatile fatty acids. Fermentation products can affect animal performance, health, and well-being. Within the GI microbes, the ruminal microbes are highly diverse, greatly contribute to fermentation, and are the most important in ruminant nutrition. Although traditional cultivation methods provided knowledge of the metabolism of GI microbes, most of the GI microbes could not be cultured on standard culture media. By contrast, amplicon sequencing of 16S rRNA genes can be used to detect unculturable microbes. Using this approach, ruminant nutritionists and microbiologists have conducted a plethora of nutritional studies, many including dietary interventions, to improve fermentation efficiency and nutrient utilization, which has greatly expanded knowledge of the GI microbiota. This review addresses the GI content sampling method, 16S rRNA gene amplicon sequencing, and bioinformatics analysis and then discusses recent studies on the various factors, such as diet, breed, gender, animal performance, and heat stress, that influence the GI microbiota and thereby ruminant nutrition.

• International Journal of Oral Biology
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• 제45권2호
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• pp.70-75
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• 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.

• Animal Systematics, Evolution and Diversity
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• 제33권4호
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• pp.274-277
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• 2017

A sea star was collected from the Korea Strait in the waters adjacent to eastern Jeju Island, Korea ($33^{\circ}39^{\prime}86^{{\prime}{\prime}}N$, $127^{\circ}33^{\prime}12^{{\prime}{\prime}}E$) at a depth of 92 m on November 5, 2016. This specimen was identified as Marginaster paucispinus Fisher, 1913, from the family Poraniidae of the order Valvatida, based on morphological characteristics. The genus Marginaster Perrier, 1881 and M. paucispinus, which were first reported in the South China Sea, are new to the Korean fauna. Partial sequences of mitochondrial COI and 16S ribosomal RNA of M. paucispinus were have been determined for the first time and were deposited in GenBank. They are the first molecular records for the genus Marginaster.

• Korean Journal of Microbiology
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• 제41권2호
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제21권7호
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• pp.312-320
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• 2020

The objective of the study was to undertake a phylogenetic diversity census of ruminal archaea based on a meta-analysis of 16S rRNA gene sequences that were publicly available in the Ribosomal Database Project. A total of 8,416 sequences were retrieved from the Ribosomal Database Project (release 11, update 5) and included in the construction of a taxonomy tree. Species-level operational taxonomic units (OTUs) were analyzed at a 97% sequence similarity by using the QIIME program. Of the 8,416 sequences, 8,412 were classified into one of three phyla; however, the remaining four sequences could not be classified into a known phylum. The Euryarchaeota phylum was predominant and accounted for 99.8% of the archaeal sequences examined. Among the Euryarchaeota, 65.4% were assigned to Methanobrevibacter, followed by Methanosphaera (10.4%), Methanomassillicoccus (10.4%), Methanomicrobium (7.9%), Methanobacterium (1.9%), Methanimicrococcus (0.5%), Methanosarcina (0.1%), and Methanoculleus (0.1%). The 7,544 sequences that had been trimmed to the V2 and V3 regions clustered into 493 OTUs. Only 17 of those 493 OTUs were dominant groups and accounted for more than 1% of the 7,544 sequences. These results can help guide future research into the dominant ruminal methanogens that significantly contribute to methane emissions from ruminants, research that may lead to the development of anti-methanogenic compounds that inhibit these methanogens regardless of diet or animal species.

• Biomedical Science Letters
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• 제18권3호
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• pp.299-306
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• 2012

Recently, the prevalence of 16S rRNA methylase conferring high-level resistance to aminoglycosides has been increasing in Gram-negative bacilli globally. We determined the prevalence and genotype of these methylase-producing bacteria, and characterized the co-resistance to ${\beta}$-lactam antibiotics and quinolone in Gram-negative clinical isolates collected in 2010 at a hospital in Korea. Among 65 amikacin-resistant isolates screened from 864 Gram-negative bacilli (GNB), 16S rRNA methylase genes were detected from 49 isolates, including Acinetobacter baumannii (43), Klebsiella pneumoniae (2), Proteus mirabilis (2) and Serratia marcescens (1), Empedobacter brevis (1). All of the 16S rRNA methylase genotype was armA and no variant sequences of amplified PCR products for armA were noted. The 16S rRNA methylase producing bacteria showed much higher resistance to aminoglycoside for Enterobacteriaceae and glucose non-fermenting (NF)-GNB and to imipenem for glucose NF-GNB, than the non-producing isolates. All of the 16S rRNA methylase producing Enterobacteriaceae had the extended-spectrum-${\beta}$-lactamase. In addition, two K. pneumoniae concurrently produced both plasmid-mediated AmpC ${\beta}$-lactamase and qnrB gene. All of the amikacin-resistant A. baumannii (43) co-harbored armA 16S rRNA methylase and $bla_{OXA-23}$ carbapenemase. In conclusion, 16S rRNA methylase producing bacteria were very prevalent among GNB in South Korea, and were commonly associated with co-resistance, including carbapenem and quinolone.