• Journal of Species Research
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• v.12 no.4
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• pp.374-414
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• 2023

As part of a comprehensive investigation of indigenous prokaryotic species in Republic of Korea in 2022, 156 bacterial strains were isolated from diverse environmental habitats. These strains were assigned to six phyla, namely Acidobacteriota, Deinococcota, Actinomycetota, Bacillota, Bacteroidota, and Pseudomonadota. Each strain was identified based on 16S rRNA gene sequence similarity (>98.7%) and the formation of robust phylogenetic clades with their closest reported species. Among isolates, there is one species belonging to the phylum Acidobacteriota, one species belonging to the phylum Deinococcota, 28 species belonging to the phylum Actinomycetota, 19 species belonging to the phylum Bacillota, 19 species belonging to the phylum Bacteroidota, and 88 species belonging to the phylum Pseudomonadota (comprising 34 species of the class Alphaproteobacteria, 20 species of the class Betaproteobacteria, and 34 species of the class Gammaproteobacteria). Based on 16S rRNA gene sequence analysis, each strain was assigned to independent and predefined bacterial species. Since there were no published or official reports regarding these 156 isolates in Republic of Korea, they are reported as unrecorded species in Republic of Korea. The Gram stain, colony and cell morphology, basic biochemical characteristic, isolation source, and strain ID of each species are described in the species descriptions.

• Journal of Species Research
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• v.12 no.4
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• pp.415-429
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• 2023

As part of a comprehensive investigation of indigenous prokaryotic species in the Republic of Korea, 37 bacterial strains belonging to 36 species were isolated from diverse environmental habitats. These strains were assigned to five phyla, namely Deinococcota, Actinomycetota, Bacillota, Bacteroidota, and Pseudomonadota. Each strain was identified based on 16S rRNA gene sequence similarity (>98.7%) and the formation of definite phylogenetic clades with their closest reported species. Among isolates, there is one species belonging to the phylum Deinococcota, five species belonging to the phylum Actinomycetota, four species belonging to the phylum Bacillota, nine species belonging to the phylum Bacteroidota, and 17 species belonging to the phylum Pseudomonadota (comprising eight species of the class Alphaproteobacteria, one species of the class Betaproteobacteria, and eight species of the class Gammaproteobacteria). Based on 16S rRNA gene sequence analysis, each strain was assigned to independent and predefined bacterial species. Since there were no published or official reports regarding these 36 species in the Republic of Korea, they have been reported as unrecorded species in the Republic of Korea. Their Gram stain, cell morphology, colony, basic biochemical characteristics, strain ID, and isolation source of each species are described in the species descriptions.

• Journal of Species Research
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• v.12 no.3
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• pp.229-239
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• 2023

We isolated and identified 25 unrecorded bacterial species belonging to the phylum Actinomycetota found in the Republic of Korea. Sequence comparison of 16S rRNA was performed using the NCBI BLAST and EzBioCloud database to identify 25 species, which had a 16S rRNA gene sequence similarity of >98.8% and were allocated as unrecorded species in the Republic of Korea. Among the 25 unrecorded bacterial strains, Streptomyces was the most common with nine species, followed by Leifsonia with two species. Isoptericola, Nocardioides, Dermacoccus, Sinomonas, Patulibacter, Marmoricola, Allobranchiibius, Aldersonia, Actinokineospora, Agromyces, Aeromicrobium, Cellulomonas, and Gordonia with one species each were also found. Twenty-five unrecorded species were excavated in various environments, such as tidal flats, ferns, soil, pine cones, moss, mud, wetlands, and plants. These isolates were characterized on the basis of their phylogenetic, biochemical properties, and morphological data, and species descriptions were provided.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.215-222
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• 2023

In 2022, research for native prokaryotic species in Korea reported 10 unrecorded bacterial strains affiliated to phyla Actinomycetota, Bacillota, and Pseudomonadota. The strains formed monophyletic clades with the most closely related species (with ≥98.7% sequence similarity) in the 16S rRNA gene sequencing. Among them, four species of the phylum Actinomycetota, two species of the phylum Bacillota, and four species of the phylum Pseudomonadota have not been reported in Korea, suggesting unrecorded species in Korea. Information on strains such as Gram staining reaction, colony and cell morphology, biochemical characteristics, and isolation sources were provided in the species description.

• The Journal of Engineering Geology
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• v.33 no.2
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• pp.257-273
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• 2023

Hydrochemical characteristics and microbial communities of spring (Samtong), surface water, and groundwater in Cheorwon, Korea, were analyzed. Field surveys and water quality analyses were undertaken at 10 sampling points for five spring, two surface, and three groundwater samples on 15 December 2022. Hydrochemical analysis revealed that most water samples were Ca-HCO₃ type and that water-rock interactions were the predominant mineral source. Radon concentrations were <1 kBq m^-3 for surface water, 1~10 kBq m^-3 for spring water, and 1~1,000 kq m^-3 for groundwater. Microbial cluster analysis showed that the main phyla were Proteobacteria, Planctomyceta, Verrucomicrobia, Acidobacteria, and Actinomycetota.Non-metric multidimensional scaling (NMDS) analysis indicated that water temperature, pH, and Si content were closely related to microorganism content. NMDS and canonical correspondence analysis results revealed that environmental factors affecting spring water were temperature, and Mg and Si concentrations, particularly for Acidobacteria and Proteobacteria, and Pseudomonas brenneri. Both hydrochemical and microbial community analyses yielded similar results at some spring and groundwater sampling points, likely due to the effects of a basalt aquifer.

• Journal of Species Research
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• v.12 no.spc2
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• pp.1-6
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• 2023

During an investigation into the indigenous prokaryotic species diversity in Korea, a total of five bacterial strains were isolated from various environments in Korea. The isolated bacterial strains were identified by analyzing their 16S rRNA gene sequences, and those with a minimum of 98.7% sequence similarity with known bacterial species but not reported in Korea were designated as unrecorded species. These isolates were assigned to three phyla, five orders, five families, and five different genera. The isolates were identified as Cumulibacter manganitolerans (99.1%) and Myolicibacterium tusciae (98.7%) of the class Actinomycetes; Bacillus marasmi (99.9%) of the class Bacilli; and Novosphingobium mathurense (100%) and Microvirga ossetica (98.8%) of the class Alphaproteobacteria. Gram reaction, colony and cellular morphology, basic biochemical characteristics, and phylogenetic position of theses isolates are also described.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.308-324
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• 2023

This study investigated unrecorded freshwater bacterial species in Korea. Water and sediment samples were collected from the Nakdong River basin from 2020-2022. Bacterial isolates obtained through the conventional culture method with commercial media were subjected to 16S rRNA gene sequencing to identify unrecorded bacterial species. Results of 16S rRNA gene sequencing of the bacterial isolates revealed that a total of 44 bacterial isolates shared 16S rRNA gene sequence similarities of more than 98.65%, with validly published bacterial species not reported in Korea yet. These isolates were phylogenetically assigned to 4 phyla, 7 classes, 21 orders, 33 families, and 42 genera. A total of 2, 6, 12, and 24 species belonged to phyla Bacillota, Bacteroidota, Actinomycetota, and Pseudomonadota, respectively. Here, we provide details of these 44 unrecorded bacterial species, including Gram staining, colony and cellular morphologies, biochemical properties, and phylogenetic position.