• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.531-536
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• 2009

A urease-positive bacterium isolated from sea water was identified as Photobacterium sp. by morphological, biochemical, and 16s rRNA gene analyses and named Photobacterium sp. strain HA-2. 2.0-fold increase enzyme activity was observed in LB medium containing 3% NaCl and 0.1% urea or not and the enzyme activity was 16.0-fold lower compared to urease-positive Vibrio parahaemolyticus AQ4673 strain when grown in the LB medium containing 3% NaCl with 0.1% urea. The cloning and sequencing of Photobacterium sp. strain HA-2 urease gene cluster is currently being analyzed in our laboratory.

• Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.93-99
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• 2013

In 2009, a systemic megalocytivirus infection associated with high mortality was detected for the first time in cultured starry flounder Platichthys stellatus in Korea. Diseased starry flounder had pale bodies and gill coloring and enlarged spleens. Histopathological examinations revealed basophilic enlarged cells in various organs of diseased starry flounder. Polymerase chain reaction (PCR) was performed on tissue samples using three published primer sets developed for the red sea bream iridovirus. PCR products were detected for all primer sets, except 1-F/1-R, which are registered by the World Organization for Animal Health (OIE). The part of the gene corresponding to the full open reading frame encoding the viral major capsid protein (MCP) was amplified by PCR. PCR products of approximately 1,581 bp were cloned, and the nucleotide sequences were analyzed phylogenetically. The MCP gene of the starry flounder iridovirus, designated SFIV0909, was identical to that of the turbot reddish body iridovirus (AB166788).

• Molecules and Cells
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• v.25 no.4
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• pp.523-530
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• 2008

In this study, the species composition and population genetic properties of the sea slater, Ligia, in South Korea were investigated using mitochondrial and nuclear gene sequences. Two groups of sea slaters, genetically isolated from each other, a Western Group (WG) and an Eastern Group (EG) were identified. These groups exhibited considerable genetic divergence from Ligia exotica, previously recorded as a species inhabiting this country. These results indicate that there may be two species of Ligia in South Korea, but there is a small probability that both groups are L. exotica. A comparison of their genetic properties indicates that WG has a higher effective population size than EG, and that EG may have experienced a recent expansion, implying that it has a shorter history in South Korea than WG. These findings suggest that the South Korean sea slater populations may have been established as a result of several colonization events that can be traced on a continental scale by phylogeographic studies of sea slaters.

• Korean Journal of Veterinary Service
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• v.40 no.3
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• pp.169-175
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• 2017

Acanthocephalan worms were harvested from the posterior intestines of the cultured marine fishes from January to July 2016 in a fish market located in Daejeon metropolitan city, Republic of Korea. Totally 450 cultured fishes (rock fish 100, olive flounder 250, red sea bream 100) were surveyed. Of the 100 red sea bream fish, 37 fishes (37%) were diagnosed as positive for Longicollum pagrosomi by light, electron microscopic and molecular examination. The number of worm was 25~78 (mean $51{\pm}13$). However, we can't found any worm from the cultured rock fish and olive flounder. After sequencing, none of Pomphorhynchidae family are not identical based on 18S rRNA gene, and this data were identified with the first report for 18S rRNA gene sequence of L. pagrosomi. Furthermore, we confirmed that L. pagrosomi of the cultured red sea bream in Republic of Korea is very common parasite.

• Journal of Species Research
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• v.13 no.3
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• pp.310-317
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• 2024

Various samples from island and coastal ecosystems in South Korea were investigated to discover unrecorded bacterial species. Soils from these areas, along with seawater samples, were plated on marine agar and R2A agar (containing 3% sea salt). From these samples, approximately 1,070 bacterial strains were isolated as single colonies and identified using 16S rRNA gene sequences. A total of 20 strains, which exhibited at least 98.7% similarity in their 16S rRNA gene sequences to those of validly published bacterial species not yet reported in Korea, were identified as unrecorded bacterial species. These strains belonged to three phyla, six classes, 10 orders, 14 families, and 16 genera. These were assigned as follows: Thioclava, Breoghania, Acidovorax, Erythrobacter, Paracoccus, Jiella, Aurantimonas, and Qipengyuania within the class Alphaproteobacteria; Pseudomonas, Cobetia, and Rheinheimera within the class Gammaproteobacteria; Aequorivita, Leeuwenhoekiella, and Polaribacter within the class Flavobacteriia; Algoriphagus within the class Cytophagia; and Microbacterium within the class Actinobacteria. The unreported species underwent further taxonomic characterization, which included assessments of Gram reaction, colony and cell morphology, biochemical and phylogenetic characteristics.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.535-541
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• 2017

Two Gram-staining-negative, red-pinkish, coccus-shaped, non-motile, and aerobic bacterial strains, designated $Ant21^T$ and Ant22, were isolated from the Antarctic coastal sea water. Strains $Ant21^T$ and Ant22 showed UVC and gamma radiation resistance. Phylogenetic analyses based on 16S rRNA gene sequences determined that these strains belong to the genus Deinococcus. Through the analyses of the 16S rRNA gene sequences, strains $Ant21^T$ and Ant22 were found to have 97.7% and 97.8% similarity to Deinococcus marmoris DSM $12784^T$ and 97.0% and 97.2% similarity to Deinococcus saxicola AA-$1444^T$, respectively. The sequence similarity with the type strains of other Deinococcus species was less than 96.9% for both strains. Strains $Ant21^T$ and Ant22 shared relatively high 16S rRNA gene sequence similarity (99.3%) and had a closely related DNA reassociation value of $84{\pm}0.5%$. Meanwhile, they showed a low level of DNA-DNA hybridization (<30%) with other closely related species of the genus Deinococcus. The two strains also showed typical chemotaxonomic features for the genus Deinococcus, in terms of the major polar lipid (phosphoglycolipid) and the major fatty acids ($C_{16:0}$, $C_{16:1}$ ${\omega}6c/{\omega}7c$, $iso-C_{17:0}$, and $iso-C_{15:0}$). They grew at temperatures between $4^{\circ}C$ and $30^{\circ}C$ and at pH values of 6.0-8.0. Based on the physiological characteristics, the 16S rRNA gene sequence analysis results, and the low DNA-DNA reassociation level with Deionococcus marmoris, strains $Ant21^T$ ($=KEMB\;9004-167^T$ $=JCM\;31436^T$) and Ant22 (KEMB 9004-168 =JCM 31437) represent novel species belonging to the genus Deinococcus, for which the name Deinococcus rubrus is proposed.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.567-573
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• 2011

We investigated the phylogenetic diversity of ammoniaoxidizing bacteria (AOB) in Yellow Sea continental shelf sediment by the cloning and sequencing of PCR-amplified amoA and 16S rRNA genes. Phylogenetic analysis of the amoA-related clones revealed that the diversity of AOB was extremely low at the study site. The majority (92.7%) of amoA clones obtained belonged to a single cluster, environmental amoA cluster-3, the taxonomic position of which was previously unknown. Phylogenetic analysis on AOB-specific 16S rRNA gene sequences also demonstrated a very low diversity. All of the cloned 16S rRNA gene sequences comprised a single phylotype that belonged to the members of uncultured Nitrosospira cluster-1, suggesting that AOB belonging to the uncultured Nitrosospira cluster-1 could carry amoA sequences of environmental amoA cluster-3.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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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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• v.38 no.3
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• pp.263-272
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• 2010

One hundred sixty three strains showing different colony morphological characteristics on different concentration of marine agar (MA) plates were isolated from ambient seawater near Dokdo island. Bacterial diversity and distributions were studied by phylogenetic analysis of the partial 16S rRNA gene sequences. One hundred sixty three strains were partially sequenced and analyzed phylogenetically. They were composed of 5 phyla, of which gamma-proteobacteria (58%), alpha-proteobacteria (20%), bacteriodetes (16%) were predominant. They were affiliated with 90 species. The 16S rRNA sequence similarity of the isolates was in 93.3 to 100 % range to reported sequence data. Thirty six isolates of among them were assumed to be novel species candidates based on similarity analysis of the 16S rRNA gene sequences. Overall, Proteobacteria and Bacteriodetes of the Dokdo coastal sea water showed a high diversity.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.222-226
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• 2007

Proteases are degradative enzymes which hydrolyze a peptide bond between amino acids and they are abundantly applied to commercial field. In order to screen new source of pretense, bacteria secreting extracellular pretense were isolated by enrichment culture from deep sea water samples of East Sea, Korea. A bacterium, named as HJ19, showed the best growth and the largest clear zone in plates supplemented skim milk at $30^{\circ}C$. The partial DNA sequence analysis of the 16S rRNA gene, phenotypic tests and morphology identified that this strain was In genus Micrococcus. The strain HJ19 could not grow at $10^{\circ}C$ but it started growth and showed pretense activity at $20^{\circ}C$. The optimal growth was at $37^{\circ}C$ and the maximal protease activity at $30^{\circ}C$ was about 480unit/ml.