Kyung June Yim

Rhodopirellula rosea sp. nov., a novel bacterium isolated from an ark clam Scapharca broughtonii.

A novel Gram-negative, motile, and ovoid-shaped strain, LHWP3T, which belonged to the family Planctomycetaceae in the phylum Planctomycetes, was isolated from a dead ark clam Scapharca broughtonii collected during a mass mortality event on the south coast of Korea. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the isolate was most closely related to the type strain of Rhodopirellulabaltica, with a shared 16S rRNA gene sequence similarity of 94.8%. The isolate grew optimally at 30°C in 4–6% (w/v) NaCl, and at pH 7. The major isoprenoid quinone was menaquinone-6 (MK-6). The dominant polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, and unidentified polar lipids. The predominant cellular fatty acids were C16:0, C18:1ω9c, and C18:0. The genomic DNA G+C content of strain LHWP3T was 53.0 mol%. Based on polyphasic taxonomic analyses, strain LHWP3T should be classified as a novel species in the genus Rhodopirellula in the family Planctomycetaceae, for which the name Rhodopirellula rosea sp. nov. is proposed. The type strain is LHWP3T (=KACC 15560T =JCM 17759T).

Phylogenetic analysis of microalgae based on highly abundant proteins using mass spectrometry

The blooms of toxic phototrophic microorganisms, such as microalgae and cyanobacteria, which are typically found in freshwater and marine environments, are becoming more frequent and problematic in aquatic systems. Due to accumulation of toxic algae, harmful algal blooms (HABs) exert negative effects on aquatic systems. Therefore, rapid detection of harmful microalgae is important for monitoring the occurrence of HABs. Mass spectrometry-based methods have become sensitive, specific techniques for the identification and characterization of microorganisms. Matrix-assisted laser desorption/ionization (MALDI) with time-of-flight (TOF) mass spectrometry (MS) allows us to measure a unique molecular fingerprint of highly abundant proteins in a microorganism and has been used for the rapid, accurate identification of bacteria and fungi in clinical microbiology. Here, we tested the specificity of MALDI-TOF MS using microalgal strains (Heterocapsa, Alexandrium, Nannochloropsis, Chaetoceros, Chlorella, and Dunaliella spp.). Our research suggested that this method was comparable in terms of the rapid identification of microalgea to conventional methods based on genetic information and morphology. Thus, this efficient mass spectrometry-based technique may have applications in the rapid identification of harmful microorganisms from aquatic environmental samples.

Halolamina sediminis sp. nov., an extremely halophilic archaeon isolated from solar salt

An extremely halophilic archaeal strain, halo-7T, was isolated from brine sediment of the Gomso solar saltern, Republic of Korea. Cells of strain halo-7T were pleomorphic, stained Gram-negative, lysed in distilled water and formed red-pigmented colonies. Strain halo-7T grew in the range of 25-45°C (optimum 37-40°C), pH 6.5-9.5 (optimum pH 7.0-8.0), 15-30% (w/v) NaCl (optimum, 20-25%), and 0.05-0.5 M MgCl2 (optimum 0.1-0.3 M). The minimal NaCl concentration to prevent cell lysis of strain halo-7T was 10% (w/v). The major polar lipids of the isolate were phosphatidylglycerol, phosphatidylglycerolphosphate methyl ester, an unidentified phospholipid, an unidentified lipid, and two unidentified glycolipids. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain halo-7T is closely related to the members of the genus Halolamina, Halolamina salina WSY15-H3T (98.7% 16S rRNA gene sequence similarity), Halolamina pelagica TBN21T (98.2%) and Halolamina rubra CBA1107T (97.4%). The genomic DNA G+C content determined for strain halo-7T (68.0 mol%) was slightly higher than those of H. salina JCM 18549T and H. rubra CBA1107T. DNA-DNA hybridization values between strain halo-7T and reference strains were < 25%. Based on phenotypic, chemotaxonomic and phylogenetic properties, we describe a novel species of the genus Halolamina, represented by strain halo-7T, for which we propose the name Halolamina sediminis sp. nov. The type strain is halo-7T ( = JCM 30187T = CECT 8739T).

Occurrence of viable, red-pigmented haloarchaea in the plumage of captive flamingoes

Flamingoes (Phoenicopterus spp.) whose plumage displays elegant colors, inhabit warm regions close to the ocean throughout the world. The pink or reddish color of their plumage originates from carotenoids ingested from carotenoid-abundant food sources, since flamingoes are unable to synthesize these compounds de novo. In this study, viable red-colored archaeal strains classified as extremely halophilic archaea (i.e., haloarchaea) and belonging to the genera Halococcus and Halogeometricum were isolated from the plumage of flamingoes in captivity. Detailed analysis for haloarchaeal community structure in flamingo feathers based on metagenomic data identified several haloarchaeal genera and unclassified sequences of the class Halobacteria at the genus level. Carotenoid pigment analyses showed that a bacterioruberin precursor carotenoid in haloarchaea was identical to one of the pigments found in flamingo plumage. To the best of our knowledge, this is the first report of viable extremophilic archaea in avian plumage, thus contributing to our understanding of the ecology of haloarchaea. The potential influence of haloarchaea as an environmental factor determining avian plumage coloration should be investigated in further studies.

Paenibacillus marinisediminis sp. nov., a bacterium isolated from marine sediment.

A Gram-negative, nonmotile, endospore-forming, rod-shaped bacterial strain LHW35T, which belonged to the genus Paenibacillus, was isolated from marine sediment collected from the south coast of the Republic of Korea. A phylogenetic analysis of 16S rRNA gene sequences indicated that strain LHW35T was most closely related to Paenibacillus taiwanensis G-soil-2-3T (97.2% similarity). The optimal growth conditions for strain LHW35T were 37°C, pH 6.0, and 0% (w/v) NaCl. The main isoprenoid quinone was menaquinone-7 (MK-7) and the major polyamine was spermidine. The diamino acid present in the cell-wall peptidoglycan was meso-diaminopimelic acid. The major fatty acids were anteiso-C15:0 and C16:0. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, unidentified amino-hospholipids, unidentified phospholipids, and unidentified polar lipids. A DNA-DNA hybridization experiment using the type strain of P. taiwanensis indicated <40% relatedness. The DNA G+C content was 45.0 mol%. Based on these phylogenetic, genomic, and phenotypic analyses, strain LHW35T should be classified as a novel species within the genus Paenibacillus, for which the name Paenibacillus marinisediminis sp. nov. is proposed. The type strain is LHW35T (=KACC 16317T =JCM 17886T).

Gillisia marina sp. nov., from seashore sand, and emended description of the genus Gillisia

A Gram-staining-negative, strictly aerobic, rod-shaped bacterium, designated CBA3202(T), was isolated from seashore sand on Jeju Island, Republic of Korea. Based on the 16S rRNA gene sequence analysis, strain CBA3202(T) was allocated to the genus Gillisia (family Flavobacteriaceae) and was most closely related to the type strain of Gillisia mitskevichiae (99.0 % 16S rRNA gene sequence similarity). Optimal growth occurred at 25 °C and with 3 % NaCl. The only isoprenoid quinone was menaquinone-6 (MK-6), the predominant fatty acids were C16 : 0, iso-C15 : 1 G, iso-C16 : 0 and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), and the DNA G+C content was 34.9 mol%. The polar lipids were phosphatidylethanolamine, two unidentified aminolipids and several unidentified polar lipids. Based on phylogenetic inference and phenotypic data, we conclude that strain CBA3202(T) represents a novel species of the genus Gillisia, for which the name Gillisia marina sp. nov. is proposed. The type strain is CBA3202(T) ( = KACC 16693(T) = KCTC 32030(T) = JCM 18402(T)). An emended description of the genus Gillisia is also provided.

Draft Genome Sequence of Gillisia sp. Strain CBA3202, a Novel Member of the Genus Gillisia, Which Belongs to the Family Flavobacteriaceae

Gillisia sp. strain CBA3202, which belongs to the family Flavobacteriaceae, was isolated from sand of the seashore on Jeju Island, Republic of Korea. The draft genome of Gillisia sp. CBA3202 contains 2,981,404 bp with a G+C content of 34.9%. This is the second genome sequence of the Gillisia strains.

Vulcanisaeta thermophila sp. nov., a hyperthermophilic and acidophilic crenarchaeon isolated from solfataric soil.

An anaerobic, rod-shaped, hyperthermophilic and acidophilic crenarchaeon, designated strain CBA1501(T), was isolated from solfataric soil of the Mayon volcano in the Republic of the Philippines. Phylogenetic analysis showed that strain CBA1501(T) is affiliated with the genus Vulcanisaeta in the phylum Crenarchaeota. DNA sequence similarities between the 16S rRNA gene of strain CBA1501(T) and those of Vulcanisaeta distributa IC-017(T) and Vulcanisaeta souniana IC-059(T) were 98.5 and 97.4 %, respectively. Strain CBA1501(T) grew between 75-90 °C, over a pH range of 4.0-6.0 and in the presence of 0-1.0 % (w/v) NaCl, with optimal growth occurring at 85 °C, pH 5.0, and with 0 % (w/v) NaCl. Fumarate, malate, oxidized glutathione, sulfur and thiosulfate were used as final electron acceptors, but FeCl3, nitrate and sulfate were not. The DNA G+C content of strain CBA1501(T) was 43.1 mol%. On the basis of polyphasic taxonomic analysis, strain CBA1501(T) represents a novel species of the genus Vulcanisaeta in the phylum Crenarchaeota, for which we propose the name Vulcanisaeta thermophila sp. nov. The type strain is CBA1501(T) ( = ATCC BAA-2415(T) = JCM 17228(T)).

Characterisation of inorganic elements and volatile organic compounds in the dried sea cucumber Stichopus japonicus

The sea cucumber Stichopus japonicus lives in a variety of marine habitats and is an important cultivated edible aquatic species in East Asia. In this study, S. japonicus, collected from the sea near Jeju Island of Korea, was lyophilised or vacuum-dried and then analysed by gas chromatography-mass spectrometry (GC-MS) or inductively coupled plasma mass spectrometry (ICP-MS). The GC-MS profiles of vacuum-dried and lyophilised samples differed. Based on direct injection and static headspace analysis, 37 volatile organic compounds (VOCs) were identified in vacuum-dried samples and 33 VOCs were identified in lyophilised samples. Therefore, the odour of vacuum-dried sea cucumber is thought to be due to the presence of various VOCs that are absent in lyophilised sea cucumber. According to ICP-MS analysis, the levels of 15 inorganic elements were slightly higher in lyophilised samples than in vacuum-dried samples. The results of the inorganic and organic chemical analyses provide information about the composition of dried sea cucumber.

Draft genome sequence of Halorubrum halophilum B8T, an extremely halophilic archaeon isolated from salt-fermented seafood

The extremely halophilic archaeon, Halorubrum halophilum B8(T) (=JCM 18963(T), CECT 8278(T)) was isolated from salt-fermented seafood. We report here the draft genome of H. halophilum B8(T), containing 3,677,984bp with a G+C content of 65.1%. The genome consists of 19 genes predicted to encode esterases.