• Journal of Species Research
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• 제9권1호
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• pp.35-45
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• 2020

In 2016 and 2017, as part of a comprehensive investigation to identify the prokaryotic species in Korea, a total of 12 bacterial strains were isolated from the gastrointestinal tract and/or fecal samples of four endangered species, including reptile, bird, and marine and terrestrial mammals. Phylogenetic analysis with the 16S rRNA gene sequence was used to assign these strains to the phyla, Firmicutes, Actinobacteria or Proteobacteria. Furthermore, most of the strains Firmicutes belonged to the order Lactobacillales. Interestingly, 12 of the isolated strains have not been previously reported from the Korean Peninsula. Also, based on their high 16S rRNA gene sequence similarities(>98.7%) and formation of strong monophyletic clades with the closest type species, each isolated strain of isolates was assigned to an independent, predefined bacterial species. Gram-stain reaction, colony and cell morphology, biochemical characteristics, isolation source, and NIBR IDs are described in the species description section.

• Journal of Species Research
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• 제12권3호
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• pp.212-223
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• 2023

A total of 30 bacterial strains were identified in the classes Betaproteobacteria and Gammaproteobacteria in the study of prokaryotic species in Korea. These strains were isolated from a variety of environmental sources, including soil, tidal flat, mud, wetland, pine cone, seaweed, sea sediment, and brackish water. Phylogenetic analysis showed that isolates were identified based on high 16S rRNA gene sequence similarities (≥98.7%) with the predefined bacterial type species. In this study, we present data on previously unreported species from Korea, including 10 species from three families of one order in the class Betaproteobacteria and 20 species from 12 families of nine order in the class Gammaproteobacteria. Morphological, biochemical characteristics, isolation sources, and NIBR deposit numbers are provided in the description sections.

• 환경생물
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• 제41권3호
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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.

• 한국균학회지
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• 제21권4호
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• pp.293-300
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• 1993

Enzyme AAT, GmDH, ME, GPI, LDH 그리고 IDH에 대해 각각 아홉, 일곱. 넷, 아홉, 일곱 그리고 네개의 서로 다른 phenotype이 관찰되었다. Sugarcane field에서 분기한 종명이 밝혀지지 않은 여섯개의 sterile isolate 모두 여섯개의 enzyme에 대해 동일한 위치에 band를 형성하였다. 이 phenotype들은 이미 밝혀진 Pythium species와는 다른 위치에서 band를 형성하였다. 종명이 밝혀지지 않은 Pythium isolate중 isolate 145와 299는 여섯개의 enzyme에 대해서 동일한 위치에서 band가 형성되었고, 다른 isolate들은 다른 위치에서 band를 형성하였다. 다섯개의 Pythium heterothallicum isolate들은 IDH를 제외한 모든 enzyme에 대해서 동일한 위치에서 band를 형성하였다. 두개 그리고 세개의 P. torulosum isolate가 AAT, GmDH 그리고 ME와 GPI,LDH 그리고 IDH 에 대해 각각 동일한 위치에 band를 형성하였다. 한개의 P. spinosum 과 P. irregulare isolate 각각이 enzyme AAT, GmDH 그리고 GPI에 대해 동일한 위치에 band를 형성하였다. 결론적으로, sterile Pythium isolate 들은 intraspecies level에서는 similarity 가 100%였지만, P. heterothallicum 그리고 Pythium spinosum과는 무관함이 밝혀졌고 isolate 306 을 제외한 다른 Pythium species들과는 전반적으로 낮은 상관성을 나타내었다 . 서로 다른 species간의 상관성은 몇몇 경우를 제외하고는 전반적으로 매우 낮았다.

• Journal of Yeungnam Medical Science
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• 제19권1호
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• pp.1-10
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• 2002

With the establishment of rapid sequence analysis of 16S rRNA and the recognition of its potential to determine the phylogenetic position of any prokaryotic organism, the role of 16S rRNA similarities in the present species definition in bacteriology need to be clarified. Comparative studies clearly reveal the limitations of the sequence analysis of this conserved gene and gene product in the determination of relationship at the pathogenic strain level for which DNA-DNA reassociation experiments still constitute the superior method. Since today the primary structure of 16S rRNA is easier to determine than hybridization between DNA strands, the strength of the sequence analysis is to recognize the level at which DNA pairing studies need to be performed, which certainly applies to similarities of 97% and higher.

• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.168-175
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• 2007

We report here on the cultivation of numerous novel bacterial species from a eutrophic freshwater pond. A total of 60 strains, 15 strains per each culture medium, were obtained from the surface of a eutrophic freshwater pond by employing a conventional dilution-plating method with four different kinds of culture media, including R2A, 1/10R2A, PCA, and 1/10PCA. Among the 60 strains isolated, 27 strains showed less than 97% 16S rRNA gene sequence similarities to validly published species, and thus they are considered to comprise 19 novel species. Of the 27 strains assigned to the novel species, the majority of the strains (20 strains) were affiliated with the Alphaproteobacteria and Betaproteobacteria. The remaining 7 strains were affiliated with the Gammaproteobacteria, Firmicutes, Actinobacteria, and Deinococci. Because we have isolated 19 novel species from a usual freshwater pond using a conventional culturing technique, our results suggest that an unexplored ecosystem, even if it looks like a common ecosystem found elsewhere, harbors diverse unidentified microbes, which will be definitely further characterized.

• Journal of Species Research
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• 제6권spc호
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• pp.185-214
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• 2017

The genus Phyllopodopsyllus T. Scott, 1906 is nearly cosmopolitan and contains around 60 valid species, but has not been previously recorded in Korea. One of the reasons is probably the paucity of research in marginal habitats, such as marine interstitial. I describe two new species here. Numerous specimens of both sexes of P. kitazimai sp. nov. were collected from a beach near Yeongdeok, while only two females of P. busanensis sp. nov. were collected from a beach near Busan. The new species differ in numerous macro-morphological characters, such as the segmentation and armature of the antennula, armature of the mandibula, maxillula, maxilliped, and the first three swimming legs, as well as the shape of the caudal rami and the female genital field. However, they show very little difference in the number and position of cuticular organs (pores and sensilla) on all somites, which might prove these rarely used micro-characters to be useful in the reconstruction of phylogenetic relationships in this group of harpacticoids. Both species have their closest relatives in Japan. Phyllopodopsyllus kitazimai is morphologically most similar to P. punctatus Kitazima, 1981, but can be distinguished by much longer third exopodal segments of the third and fourth swimming legs. Phyllopodopsyllus busanensis shares the largest number of morphological similarities with P. setouchiensis Kitazima, 1981, but can be distinguished by shorter caudal rami. A key to species is also provided.

• ALGAE
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• 제21권3호
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• pp.295-305
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• 2006

The purpose of the study is to understand the ecological characteristics of the early stage of community formation of epilithic diatoms. The samples were daily collected from a site of the Kumho River during 70 days from October 13 to December 21 in 2002. Total 126 diatom taxa collected in the study were classified into 114 species and 12 varieties belonging to 26 genera. About 80% of the taxa collected from the artificial substrata during the whole studying period were observed until tenth day from the start time of the study. In the study the successional process of the diatom community was divided into the three stages of the early, the middle and the later by cluster analysis based on the similarities in species composition among the communities. Cocconeis placentula Ehrenb. and C. placentula var. lineata (Ehrenb.) V.H., horizontally positioned species, would be divided into the early successional species, and Diatoma vulgre Bory, vertically positioned species, was the later successional species. Cell densities and species composition of the diatoms on the artificial substrata were closely similar to them of natural substrata after 40th day from the start time of the study.

• Journal of Species Research
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• 제9권4호
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• pp.339-345
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• 2020

The Earth contains billions of microbial species, although the vast majority cannot be cultured in laboratories and are thus considered unidentified and uncharacterized. Extremophiles are microorganisms that thrive in extreme conditions, including temperature, salinity, and pH. Extremophilic microorganisms have provided important insights for biological, metabolic, and evolutionary studies. Between 2017 and 2019, as part of a comprehensive investigation to identify bacterial species in Korea, eight bacterial strains were isolated from marine and non-marine environments in Jeju Island. These strains were cultured under extreme salinity or pH conditions. Phylogenetic analysis using 16S ribosomal RNA(rRNA) gene sequencing indicated that all eight strains belonged to the phyla Gammaproteobacteria, Bacilli, and Alphaproteobacteria. Based on their high 16S rRNA gene sequence similarities(>98.7%) and the formation of strong monophyletic clades with their closest related species, all isolated strains were considered as an unrecorded strain, previously unidentified species. Gram stain reaction, culture conditions, colony and cell morphology, biochemical characteristics, isolation source, and National Institute of Biological Resources(NIBR) IDs are described in this article. The characterization of these unrecorded strains provides information on microorganisms living in Korea.

• Animal Systematics, Evolution and Diversity
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• 제40권2호
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• pp.130-134
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• 2024

The family Velutinidae is found in various intertidal and subtidal habitats worldwide including Arctic and Antarctic seas. They are characterized by possessing a fragile shell that is partially or entirely covered by the mantle. Eight valid species of the genus Coriocella have been reported mostly in the Indo-West Pacific. Here we report Coriocella jayi Wellens, 1996 from Korean waters for the first time and describe details of their external morphology and radula characteristics using scanning electron microscopy, and provide the mtDNA cox1 sequence as a DNA barcode sequence information. This species is distinguished from other congeneric species by having six cylinder-shaped tubercular lobes of their dorsal part of mantle body and mantle color. Phylogenetic tree using the mtDNA cox1 sequence data shows that two Coriocella species (C. jayi and C. nigra) are grouped as their respective sister among Velutinidae species, and these relationships are strongly supported by 100% bootstrap value. Despite the morphological similarities, further investigation will be needed to confirm whether the African and Korean populations can be justified as the same species with a disconnected distribution range, or represent morphologically similar but two distinct species.