Chung-Yeon Hwang

A Gram-negative, pink-coloured, rod-shaped, non-flagellated bacterium, designated CL-GP80(T), was isolated from a hypertrophic pond located within the campus of Seoul National University, Korea. Analysis of its 16S rRNA gene sequence revealed that strain CL-GP80(T) belongs to the family Sphingobacteriaceae and is closely related to Pedobacter heparinus ATCC 13125(T) (95.8 % sequence similarity) and to other members of the genus Pedobacter (90.8-95.3 % similarity). Temperature and pH ranges for g

Abstract The bacterium, Acidovorax avenae ssp. avenae causes several important plant diseases including bacterial stripe of rice, bacterial stalk rot of corn, bacterial leaf blight of oats, and red stripe of sugarcane and millet. Although the organism is seed‐borne in rice, no reliable seed assay is available. A semiselective liquid medium based on d ‐sorbitol and l ‐pyroglutamic acid (SP medium), and two sets of polymerase chain reaction (PCR) primers were designed for use in a BIO‐PCR assay fo

A Gram-staining-negative, rod-shaped and non-motile bacterium, designated CL-SS4T, was isolated from crude-oil-contaminated seawater from the west coast of Korea and was investigated by means of a polyphasic taxonomic approach. Strain CL-SS4T grew optimally at 25-30 degrees C, at pH 6.8-7.7 and in the presence of 2-3% sea salts. The major fatty acids were iso-C17:0 3-OH, iso-C15:0 and iso-C15:1 G. The major isoprenoid quinone was MK-6. The DNA G+C content was 50.7 mol%. Analysis of the 16S rRNA

Two strictly aerobic, Gram-negative, rod-shaped bacteria containing photosynthesis-related genes, designated strains CL-SK44(T) and CL-JM1(T), were isolated from a culture of the marine phytoplankton Cryptomonas sp. and coastal seawater from Korea, respectively. Phylogenetic analysis of 16S rRNA gene sequences revealed that the two strains were related to members of the genera Thalassobius (95.3-96.7 % similarity), Pelagibaca (95.3-96.0 %) and Donghicola (95.6 %) in the family Rhodobacteraceae.

Two Gram-negative, strictly aerobic bacterial strains, designated CL-AP6(T) and CL-AP22, were isolated from a culture of a green alga, Pyramimonas gelidicola, established from the Antarctic. Cells of the strains were straight rods and motile by means of a single polar flagellum. The strains grew with 0.5-8 % (w/v) NaCl (optimum, 1-2 %) and at 4-33 degrees C (optimum, 25 degrees C) and pH 6.5-9.1 (optimum, pH 7.5-8.1). The two strains shared 98.8 % 16S rRNA gene sequence similarity. Analysis of t

Abstract. Terra Nova Bay in Antarctica is a formation region for high-salinity shelf water (HSSW), which is a major source of Antarctic Bottom Water. Here, we analyze spatiotemporal salinity variability in Terra Nova Bay with implications for the local HSSW production. The salinity variations in the Drygalski Basin and eastern Terra Nova Bay near Crary Bank in the Ross Sea were investigated by analyzing hydrographic data from instrumented moorings, vessel-based profiles, and available wind and s

Two novel Gram-negative bacterial strains, designated CL-GR15(T) and CL-GR35, were isolated from coastal seawater of the east coast of Korea. Identical 16S rRNA gene sequences were found in the two strains, and it was found that the strains represented a distinct and deep evolutionary lineage of descent in the order Rhizobiales, and clustered with yet-uncultured marine bacteria. This lineage could not be associated with any of 12 known families in the order Rhizobiales. The most closely related

A Gram-negative, coccoid to rod-shaped, strictly aerobic bacterium, strain CL-GR66(T), was isolated from coastal seawater collected off Korea. The strain grew optimally in the presence of 3-5 % sea salts, at a temperature of 30 degrees C and at pH 7. The polar lipid profile of strain CL-GR66(T) comprised phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminolipids, an unidentified glycolipid and an unidentified lipid. The major fatty acids were C(18 : 1)omega

Viruses are now known to be significant contributors to bacterial mortality in the marine environment; however, to date, most studies have focused on only the more productive coastal areas. The impact of viruses in oligotrophic environments is still poorly understood, but current literature implies that the percentage of bacteria visibly infected with viruses in these areas is generally low and may often be below the detection limit normally achieved by transmission electron microscopy (i.e. < 0

A Gram-negative, almost straight, rod-shaped, non-motile bacterium, designated CL-GP79(T), was isolated from a highly eutrophic pond located within the campus of Seoul National University, Korea. Phylogenetic analyses based on 16S rRNA gene sequencing showed that strain CL-GP79(T) belongs to the family Flexibacteraceae, with Flectobacillus major as its closest relative (similarity of 95.7 %). The cellular fatty acids consist mainly of C(16 : 1)omega5c (mean +/- sd, 26.9 +/- 10.8 %), iso-C(15 : 0

A Gram-negative, rod-shaped, strictly aerobic micro-organism, designated strain CL-GR60(T), was isolated from coastal seawater from the East Sea, Korea. A 16S rRNA gene sequence analysis revealed a clear affiliation with the family Hyphomicrobiaceae. Phylogenetic analyses showed that strain CL-GR60(T) formed a robust cluster with the species of the genus Devosia at sequence similarity levels of 91.1-93.1 %; no other species in the family Hyphomicrobiaceae shared more than 90 % sequence similarit

Pontimonas salivibrio strain CL-TW6 T (=KCCM 90105 = JCM18206) was characterized as the type strain of a new genus within the Actinobacterial family Microbacteriaceae. It was isolated from a coastal marine environment in which members of Microbactericeae have not been previously characterized. The genome of P. salivibrio CL-TW6 T was a single chromosome of 1,760,810 bp. Genomes of this small size are typically found in bacteria growing slowly in oligotrophic zones and said to be streamlined. Phy

A Gram-stain-positive, rod-shaped and non-motile strain, designated PAMC 27367(T), was isolated from rainwater collected on the Bering Sea. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Rhodococcus. Phylogenetic analyses revealed that strain PAMC 27367(T) formed a robust clade with the type strains of Rhodococcus rhodnii, Rhodococcus aetherivorans and Rhodococcus ruber with 16S rRNA gene sequence similarities of 96.3 %, 95.8 % and 95.5 %, respectively.

A Gram-stain-negative, facultatively anaerobic, rod-shaped and motile strain, designated PAMC 28425T, was isolated from a sea surface microlayer sample from the Ross Sea, Antarctica. Analysis of the 16S rRNA gene sequence of strain PAMC 28425T showed an affiliation with the genus Pseudoalteromonas. Phylogenetic analyses revealed that strain PAMC 28425T formed a clade with Pseudoalteromonas prydzensis MB8-11T and Pseudoalteromonas mariniglutinosaKMM 3635T with 16S rRNA gene sequence similarities

A Gram-negative, rod-shaped, strictly aerobic bacterium, designated strain CL-SK30(T), was isolated from a culture of the marine ciliate Myrionecta rubra. 16S rRNA gene sequence analysis revealed that strain CL-SK30(T) was most closely related to Cucumibacter marinus (92.0 % similarity) and next to the type strains of species of the genus Devosia (89.8-91.3 % similarities) in the family Hyphomicrobiaceae. Phylogenetic analyses of the 16S rRNA gene sequences showed that strain CL-SK30(T) formed a