Joo Won Kang

Altererythrobacter rigui sp. nov., isolated from wetland freshwater.

A non-motile and yellow-pigmented bacterium, designated strain WW3T, was isolated from freshwater of Woopo wetland, Republic of Korea. Cells were Gram-reaction-negative, aerobic, catalase-positive and oxidase-negative. A maximum-likelihood phylogenetic tree based on 16S rRNA gene sequences showed that strain WW3T forms an independent lineage within the genus Altererythrobacter. Strain WW3T was related distantly to Altererythrobacter dongtanensisJM27T and Altererythrobacter troitsensisKMM 6042T (97.1% 16S rRNA gene sequence similarity). DNA-DNA relatedness between strain WW3T and the reference strains was low (30-41 %). The major fatty acids of strain WW3T were C17 : 1ω6c, C17 : 1ω8c, C15 : 0 2-OH and summed feature 8 comprising C18 : 1ω6c and/or C18 : 1ω7c. The predominant isoprenoid quinone of the isolate was ubiquinone-10. The DNA G+C content of strain WW3T was 63 mol%. Phenotypic characteristics distinguished strain WW3T from related species of the genus Altererythrobacter. On the basis of the evidence presented in this study,strain WW3T represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter rigui sp. nov. is proposed. The type strain is WW3T (=KCTC 42620T =JCM 30975T).

Seasonal Variations in the Bacterial Community of Gwangyang Bay Seawater

Seasonal variations in the bacterial community of Gwangyang Bay seawater were analyzed using both isolation and cultivation-independent methods. Amplified rDNA restriction analysis was applied to 200 bacterial isolates. Bacterial isolates were composed of four phyla: Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. Pyrosequencing was conducted, in addition to denaturing gradient gel electrophoresis (DGGE) of genomic DNA extracted directly from the water samples. The bacterial sequences obtained by pyrosequencing of 16S rRNA genes consisted of 24 phyla in the spring and summer, 39 in the fall, and 32 in the winter. The diversity index was high in the fall, whereas the dominancy index was high in the spring. In the spring, phylum Firmicutes was dominant, whereas phylum Proteobacteria dominated in the other three seasons. The second most dominant phyla were Proteobacteria in the spring, Firmicutes in the summer, and Bacteroidetes both in the fall and winter. Bacilliaceae was the most predominant family in the spring. Rhodobacteraceae and Bacilliaceae dominated in the summer, and Rhodobacteraceae dominated in the winter. Neither was dominant in the fall Twenty-seven bands purified from DGGE profiles were cloned and analyzed phylogenetically. In the spring, phylum Firmicutes dominated, followed by Proteobacteria. Proteobacteria dominated in all other seasons. Thus, two cultivation-independent methods for determination of seasonal variation patterns at the phylum level were in accordance with each other.

Hymenobacter coalescens sp. nov., isolated from wetland freshwater

A non-motile and rod-shaped bacterium, designated strain WW84T, was isolated from freshwater collected from the Woopo wetland (Republic of Korea). Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were C16 : 0, C18 : 0, iso-C15 : 0 and iso-C17 : 1I and/or anteiso-C17 : 1B. The strain contained MK-7 as the major isoprenoid quinone, phosphatidylethanolamine as the major polar lipid and sym-homospermidine as the major polyamine. The DNA G+C content was 59 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain WW84T forms an evolutionary lineage within the radiation including the members of the genus Hymenobacter with Hymenobactero cellatus Myx 2105T (96.96 % sequence similarity) as its nearest neighbor. A number of phenotypic characteristics distinguished strain WW84T from the related members of the genus Hymenobacter. On the basis of the evidence presented in this study, a novel species, Hymenobacter coalescens sp. nov. is proposed with strain WW84T (=KCTC 32530T=JCM 19493T) as the type strain.

Hymenobacter wooponensis sp. nov., isolated from wetland freshwater

A non-motile and rod-shaped bacterium, designated strain WM78T, was isolated from freshwater collected from the Woopo wetland (Republic of Korea). Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were iso-C15:0, anteiso-C15:0, C16:1ω7c and/or C16:1ω6c and iso-C17:1 I and/or anteiso-C17:1 B. The strain contained MK-7 as the major isoprenoid quinone, phosphatidylethanolamine as the major polar lipid and sym-homospermidine as the major polyamine. The genomic DNA G+C content was 62 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain WM78T forms evolutionary lineage within the radiation comprising members of the genus Hymenobacter with Hymenobacter gelipurpurascens Txg1T (97.7 % sequence similarity) as its nearest neighbour. A number of phenotypic characteristics distinguished strain WM78T from related members of the genus Hymenobacter. The evidence presented in this study support the designation of strain WM78T as a representative of a novel species in the genus Hymenobacter for which the name Hymenbactor wooponensis sp. nov. is proposed. The type strain is WM78T ( = KCTC 32528T = JCM 19491T).

Dokdonia lutea sp. nov., isolated from Sargassum fulvellum seaweed

A non-motile, yellow-coloured and rod-shaped bacterium, designated strain SFD34T, was isolated from seaweed collected from the South Sea, Republic of Korea. Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. Strain SFD34T contained MK-6 and phosphatidylethanolamine as the only isoprenoid quinone and major polar lipid, respectively. The DNA G+C content was 35 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain SFD34T formed evolutionary lineage within the radiation enclosing the members of the genus Dokdonia with Dokdoniapacifica SW230T (96.86 % sequence similarity) as its nearest neighbour. A number of phenotypic characteristics distinguished strain SFD34T from related members of the genus Dokdonia. On the basis of the evidence presented in this study, a novel species, Dokdonia lutea sp. nov., is proposed for strain SFD34T (=KCTC 52269T=JCM 31795T).

Hymenobacter tenuis sp. nov., isolated from wastewater of an acidic water neutralization facility

A non-motile, red-pink-coloured, rod-shaped bacterium, designated strain POB6T, was isolated from a wastewater treatment facility, Republic of Korea. Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were iso-C15 : 0, C16 : 1ω5c, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The strain contained menaquinone MK-7 as the only isoprenoid quinone, phosphatidylethanolamine as the major polar lipid and sym-homospermidine as the major polyamine. The DNA G+C content was 61 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain POB6T forms a distinct evolutionary lineage within the radiation enclosing the members of the genus Hymenobacter, sharing the highest similarity with Hymenobacterrigui WPCP131T (97.5 %) followed by Hymenobacter xinjiangensis X2-1gT (97.2 %), Hymenobacter perfusus A1-12T (97.2 %) and Hymenobacter gelipurpurascens Txg-1T (97.1 %). A number of phenotypic characteristics distinguished strain POB6T from related members of the genus Hymenobacter. On the basis of the evidence presented in this study, a novel species, Hymenobacter tenuis sp. nov., is proposed, with POB6T (=KCTC 52271T=JCM 31659T) as the type strain.

Mucilaginibacter roseus sp. nov., isolated from wetland freshwater.

A non-motile, rod-shaped and pale-pink bacterium, designated strain WS71T, was isolated from freshwater collected from the Woopo Wetland (Republic of Korea). Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), iso-C17 : 0 3-OH, C16 : 0 and iso-C15 : 0. The strain contained menaquinone 7 (MK-7) and the DNA G+C content was 39.4±0.4 mol%. The major polar lipids were phosphatidylethanolamine and an unknown aminophospholipid. A phylogenetic tree based on 16S rRNA gene sequences showed that WS71T forms an evolutionary lineage within the radiation enclosing the members of genus Mucilaginibacterwith Mucilaginibacter. soyangensis HME6664T as its nearest neighbor (98.3 % sequence similarity). DNA-DNA relatedness between WS71T and M. soyangensis HME6664T was 61.3±1.0 %. A number of phenotypic characteristics distinguished WS71T from the other members of the genus Mucilaginibacter. On the basis of the evidence presented in this study, WS71T represents a novel species, for which the name Mucilaginibacterpuniceus sp. nov. is proposed. The type strain is WS71T (=KCTC 32270T=JCM 19495T).

Mucilaginibacter puniceus sp. nov., isolated from wetland freshwater

A non-motile, rod-shaped and pale-pink bacterium, designated strain WS71T, was isolated from freshwater collected from the Woopo Wetland (Republic of Korea). Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), iso-C17 : 0 3-OH, C16 : 0 and iso-C15 : 0. The strain contained menaquinone 7 (MK-7) and the DNA G+C content was 39.4±0.4 mol%. The major polar lipids were phosphatidylethanolamine and an unknown aminophospholipid. A phylogenetic tree based on 16S rRNA gene sequences showed that WS71T forms an evolutionary lineage within the radiation enclosing the members of genus Mucilaginibacterwith Mucilaginibacter. soyangensis HME6664T as its nearest neighbor (98.3 % sequence similarity). DNA-DNA relatedness between WS71T and M. soyangensis HME6664T was 61.3±1.0 %. A number of phenotypic characteristics distinguished WS71T from the other members of the genus Mucilaginibacter. On the basis of the evidence presented in this study, WS71T represents a novel species, for which the name Mucilaginibacterpuniceus sp. nov. is proposed. The type strain is WS71T (=KCTC 32270T=JCM 19495T).

Korean indigenous bacterial species with valid names belonging to the phylum Actinobacteria

To understand the isolation and classification state of actinobacterial species with valid names for Korean indigenous isolates, isolation source, regional origin, and taxonomic affiliation of the isolates were studied. At the time of this writing, the phylum Actinobacteria consisted of only one class, Actinobacteria, including five subclasses, 10 orders, 56 families, and 330 genera. Moreover, new taxa of this phylum continue to be discovered. Korean actinobacterial species with a valid name has been reported from 1995 as Tsukamurella inchonensis isolated from a clinical specimen. In 1997, Streptomyces seoulensis was validated with the isolate from the natural Korean environment. Until Feb. 2016, 256 actinobacterial species with valid names originated from Korean territory were listed on LPSN. The species were affiliated with three subclasses (Acidimicrobidae, Actinobacteridae, and Rubrobacteridae), four orders (Acidimicrobiales, Actinomycetales, Bifidobacteriales, and Solirubrobacterales), 12 suborders, 36 families, and 93 genera. Most of the species belonged to the subclass Actinobacteridae, and almost of the members of this subclass were affiliated with the order Actinomycetales. A number of novel isolates belonged to the families Nocardioidaceae, Microbacteriaceae, Intrasporangiaceae, and Streptomycetaceae as well as the genera Nocardioides, Streptomyces, and Microbacterium. Twenty-six novel genera and one novel family, Motilibacteraceae, were created first with Korean indigenous isolates. Most of the Korean indigenous actionobacterial species were isolated from natural environments such as soil, seawater, tidal flat sediment, and fresh-water. A considerable number of species were isolated from artificial resources such as fermented foods, wastewater, compost, biofilm, and water-cooling systems or clinical specimens. Korean indigenous actinobacterial species were isolated from whole territory of Korea, and especially a large number of species were from Jeju, Gyeonggi, Jeonnam, Daejeon, and Chungnam. A large number of novel actinobacterial species continue to be discovered since the Korean government is encouraging the search for new bacterial species and researchers are endeavoring to find out novel strains from extreme or untapped environments.

Pontibacter rugosus sp. nov., isolated from seawater

A motile and rod-shaped bacterium, designated strain KYW1030T, was isolated from seawater collected from the Gwangyang bay (Republic of Korea). Cells were Gram-reaction-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B), iso-C15 : 0 and iso-C17 : 0 3-OH. The strain contained MK-7 as the major isoprenoid quinone, phosphatidylethanolamine and diphosphatidylglycerol as the major polar lipids and sym-homospermidine as the major polyamine. The DNA G+C content was 46 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain KYW1030T forms an evolutionary lineage within the radiation enclosing the members of the genus Pontibacter, with Pontibacterakesuensis AKS 1T (97.9 % 16S rRNA gene sequence similarity) as its nearest neighbour. A number of phenotypic characteristics distinguished strain KYW1030T from the related members of the genus Pontibacter. On the basis of the evidence presented in this study, a novel species, Pontibacter rugosus sp. nov., is proposed for strain KYW1030T (=KACC 18739T=JCM 31319T).