• ALGAE
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• v.31 no.4
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• pp.289-301
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• 2016

Floating debris provides substrates for dispersal of organisms by ocean currents, including algae that thrive on plastics. The 2011 earthquake and tsunami in Tohuku, Japan resulted in large amounts of debris carried by the North Pacific Current to North America from 2012 to 2016. In 2015-2016, the plastics in the debris bore a complex biota including pink algal crusts. One sample (JAW4874) was isolated into culture and a three-gene phylogeny (psbA, rbcL, and SSU) indicated it was an unknown member of the red algal class Stylonematophyceae. It is a small pulvinate crust of radiating, branched, uniseriate filaments with cells containing a single centrally suspended nucleus and a single purple to pink, multi-lobed, parietal plastid lacking a pyrenoid. Cells can be released as spores that attach and germinate to form straight filaments by transverse apical cell divisions, and subsequent longitudinal and oblique intercalary divisions produce masses of lateral branches. This alga is named Tsunamia transpacifica gen. nov. et sp. nov. Sequencing of additional samples of red algal crusts on plastics revealed another undescribed Stylonematophycean species, suggesting that these algae may be frequent on drift oceanic plastics.

• Mycobiology
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• v.47 no.4
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• pp.355-367
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• 2019

Arthonia dokdoensis sp. nov., a lichenicolous fungus from the subcosmopolitan Arthonia molendoi complex growing on crustose thalli of species of the genus Orientophila (subfamily Xanthorioideae, Teloschistaceae), as well as the lichen species Rufoplaca toktoana sp. nov. (subfamily Caloplacoideae, Teloschistaceae) similar to Rufoplaca kaernefeltiana, both from Dokdo Islands, Republic of Korea, are described, illustrated, and compared with closely related taxa. In the phylogenetic tree of the Arthoniaceae based on 12S mtSSU and RPB2 gene sequences, the phylogenetic position of the A. dokdoensis and the relationship with the A. molendoi group are illustrated, while the position of the newly described R. toktoana is confirmed by phylogenetic tree based on ITS nrDNA data.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1300-1305
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• 2017

A rod shaped, aerobic, Gram-stain-negative, and motile bacterium, strain $AR2^T$, was isolated from a water sample of Yeongsan river, Republic of Korea. Strain $AR2^T$ clustered closely with the members of the genus Chitinimonas and showed the highest 16S rRNA gene sequence similarity with Chitinimonas prasina $LY03^T$ (96.4%), Chitinimonas viridis $HMD2169^T$ (96.4%), Chitinimonas taiwanensis $cf^T$ (96.2%), and Chitinimonas koreensis $R2A43-10^T$ (94.2%). The predominant fatty acids of strain $AR2^T$ were identified to be summed feature 3 (comprising $C_{16:1}{\omega}7c$ and/or $C_{16:1}{\omega}6c$), $C_{16:0}$, and $C_{10:0}3-OH$. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were found to be the major polar lipids. The genomic DNA G+C content was 60.4 mol%. Based on the polyphasic characterization, the isolated strain $AR2^T$ is described as a representative of a novel species in the genus Chitinimonas, for which the name Chitinimonas naiadis sp. nov. (type strain =$AR2^T$ =KCTC $42755^T$ =JCM $31504^T$) is proposed.

• Mycobiology
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• v.51 no.4
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• pp.216-229
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• 2023

Acarosporaceae is a crustose lichen and is known as a species that has more than 50 multispores, and has hyaline spores. Those taxa are often found in rock and soil in mountain areas or coastal regions in Korea, and very diverse forms and species are known. However, after an overall genetic phylogenetic analysis of carbonized ascomata in 2015, species consisting only of the morphological base are newly divided, and several species of Acarosporaceae in Korea are also being discovered in this situation. As a result of analysis using internal transcribed spacer (ITS) and nuLSU gene analysis, Korean species belonged to Acarospora and Sarcogyne clade, and Acarospora classified as the Acarospora clade was mixed with the Polysporina group and the Sarcogyne clade is mixed with the Acarospora. We identified two new species (Acarospora beangnokdamensis J. S. Park & S. O. Oh, sp. nov., Sarcogyne jejuensis J. S. Park & S. O. Oh, sp. nov.) through morphological, molecular, and secondary metabolite substance and found one new record (Sarcogyne oceanica K. Knudsen & Kocourk). We have made a classification key for Acarospora and Sarcogyne in Korea and reported all information together here.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.223-228
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• 2023

Neoporphyra kitoi Ma. Abe, N. Kikuchi, Tamaki, Tom. Sato, Murase, Fujiyoshi & Mas. Kobayashi has been known as an endemic species in Japan. Its high temperature tolerance suggests that it could be advantageous for cultivation. In this study, we collected it from the Ulleungdo island, Korea and transferred it into Pyropia for a new combination, identified as Pyropia kitoi(Ma. Abe, N. Kikuchi, Tamaki, Tom. Sato, Murase, Fujiyoshi & Mas. Kobayashi) D.J. Kim, T.O. Cho & B.Y. Won comb. nov. based on morphological and molecular analyses. Pyropia kitoi is also reported as a new record species in the list of Korean macroalgal flora. Although we didn't observe the emergence of new blades from the rhizoidal cells, which is a key character for this species, our molecular analysis of rbcL revealed that our samples from Korea were congruent with "Neoporphyra kitoi" from Japan and were nested within the clade of Pyropia. The gene sequence divergence between the Korean and Japanese samples was 0-0.2%.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.265-270
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• 2010

Adipogenesis has been one of the most intensely studied models of cellular differentiation. During adipogenesis, differential expression of many adipogenesis related genes lead to profound changes in cellular, morphological, and physiological characteristics of the differentiating cells. The aim of the present study was to examine the expression levels of adipogenic candidate genes, cAMP early repressor (ICER), nephroblastoma over-expressed protein (NOV), heat shock protein beta 1 (HSPB1) and succinate dehydrogenase (SDH), during adipogenesis of bovine mesenchymal stem cells (BMSC). The BMSC were cultured in DMEM / low glucose medium with adipogenic inducers for 6 days and the expression of various candidate genes which seemed related to adipogenesis were measured by real-time PCR. This study showed that the expression of peroxisome proliferator activated receptor ${\gamma}$(PPAR${\gamma}$) and fatty acid binding protein 4 (FABP4) genes as adipogenic indicators were increased to 3.11 and 3.11 folds on day 6 than on day 0, respectively (p<0.05). To determine whether candidate genes were related to adipogenesis, the expression levels of ICER, NOV, HSPB1, and SDH genes were measured during adipogenesis in BMSC. Our results showed that the expression level of ICER gene was significantly increased to 4.12 folds (0.01729 vs. 0.07138; p<0.05), whereas NOV, HSPB1, and SDH genes were decreased to 2.89, 3.18 and 2.36 folds, respectively, on day 6 when compared to day 0. These results suggest that these candidate genes have stimulatory or inhibitory effects on adipogenesis in BMSC, indicating that these genes may be directly or indirectly related to the adipogenic event of adipose precursor cells.

• ALGAE
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• v.38 no.2
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• pp.93-110
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• 2023

Progress in phylogenomic analysis has led to a considerable re-evaluation of former cyanobacterial system, with many new taxa being established at different nomenclatural levels. The family Geminocystaceae is among cyanobacterial taxa recently described on the basis of polyphasic approach. Within this family, there are six genera: Geminocystis, Cyanobacterium, Geminobacterium, Annamia, Picocyanobacterium, and Microcrocis. The genus Geminocystis previously encompassed two species: G. herdmanii and G. papuanica. Herein, a new species G. urbisnovae was proposed under the provision of the International Code of Nomenclature for algae, fungi, and plants (ICN). Polyphasic analysis was performed for five strains from the CALU culture collection (St. Petersburg State University, Russian Federation), and they were assigned to the genus Geminocystis in accordance with high 16S rRNA gene similarity to existing species, as well as because of proximity to these species on the phylogenetic trees reconstructed with RaxML and Bayes methods. Plausibility of their assignment to a separate species of the genus Geminocystis was substantiated with smaller cell size; stenohaline freshwater ecotype; capability to complementary chromatic adaptation of second type (CA2); distinct 16S rRNA gene clustering; sequences and folding of D1-D1' and B box domains of the 16S-23S internal transcribed spacer region. The second objective pursued by this communication was to provide a survey of the family Geminocystaceae. The overall assessment was that, despite attention of many researchers, this cyanobacterial family has been understudied and, especially in the case of the crucially important genus Cyanobacterium, taxonomically problematic.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1554-1560
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• 2006

A Gram-positive, aerobic or facultative anaerobic, non motile, endospore-forming bacterial strain, designated Gsoil $114^T$, was isolated from a soil sample of a ginseng field in Pocheon Province (South Korea), and was characterized taxonomically by using a polyphasic approach. It grew well on nutrient agar medium and utilized a limited number of organic substrates as sole carbon sources, including D-xylose and some other carbohydrates, but did not utilize L-amino acids and organic acids. The isolate was positive for oxidase test but negative for catalase, and negative for degradation of macromolecules such as starch, cellulose, xylan, casein, chitin, and DNA. The G+C content of the genomic DNA was 41.8 mol%. The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major fatty acids were $anteiso-C_{15:0}$ (32.1%), $iso-C_{15:0}$ (30.5%), and $anteiso-C_{17:0}$ (30.2%). Comparative 16S rRNA gene sequence analysis showed that strain Gsoil $114^T$ fell within the radiation of the cluster comprising Bacillus species and joined Bacillus shackletonii LMG $18435^T$ with a bootstrap value of 95%. The highest 16S rRNA gene sequence similarities were found with Bacillus shackletonii LMG $18435^T$ (97.6%), Bacillus acidicola DSM $14745^T$ (96.9%), Bacillus sporothermodurans DSM $10599^T$ (96.5%), and Bacillus oleronius DSM $9356^T$ (96.5%). The phylogenetic distance from any other validly described species within the genus Bacillus was less than 96%. DNA-DNA hybridization experiments showed that the DNA-similarities between strain Gsoil $114^T$ and closest phylogenetic neighbors were less than 39%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil $114^T$ (=KCTC $13944^T$=DSMZ $18134^T$) was classified in the genus Bacillus as the type strain of a novel species, for which the name Bacillus ginsengihumi sp. nov. is proposed.

• ALGAE
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• v.38 no.1
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• pp.1-22
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• 2023

An enormous body of research is focused on finding ways to commercialize carotenoids produced by the unicellular green alga, Haematococcus, often without the benefit of a sound phylogenetic assessment. Evidence of cryptic diversity in the genus means that comparing results of pigment studies may be confounded by the absence of a phylogenetic framework. Moreover, previous work has identified unnamed strains that are likely candidates for species status. We reconstructed the phylogeny of an expanded sampling of Haematococcus isolates utilizing data from nuclear ribosomal markers (18S rRNA gene, 26S rRNA gene, internal transcribed spacer [ITS]-1, 5.8S rRNA gene, and ITS-2) and the rbcL gene. In addition, we gathered morphological, ultrastructural and pigment data from key isolates of Haematococcus. Our expanded data and taxon sampling support the concept of a new species, H. privus, found exclusively in North America. Despite overlap in numerous morphological traits, results indicate that ratios of protoplast length to width and akinete diameter may be useful for discriminating Haematococcus lineages. High growth rate and robust astaxanthin yield indicate that H. rubicundus (SAG 34-1c) is worthy of additional scrutiny as a pigment source. With the description of H. privus, the evidence supports the existence of at least five, species-level lineages in the genus. Our phylogenetic assessment provides the tools to frame future pigment investigations of Haematococcus in an updated evolutionary context. In addition, our investigation highlighted open questions regarding polyploidy and sexuality in Haematococcus which demonstrate that much remains to be discovered about this green flagellate.

• ALGAE
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• v.19 no.3
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• pp.175-190
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• 2004

The morphological and molecular characteristics of Pachydictyon coriaceum (Holmes) Okamura (1899) are described. Plants are collected from Korea all year round and have maximum height from August to September. The monthly variability of thallus growth is in the way with that of the seawater temperature. Two types of thallus structures, thick cortical layer tallus type and thin cortical cell layer type, are distinguished according to growing seasons. The habit of Korean plants is also classified into two thallus types, slender type and wide type, based on the length and the width of internodes, but this distinction between two types is not supported by either anatomical or molecular characteristics. P. coriaceum shares typical morphology in branching pattern and morphogenetic processes with the other species of Dictyota: 1) multi-cellular cortical and medullar layer in the partial of thallus, 2) same development of thallus from apical meristem cell, and 3) sub-lineage within Dictyota species lineage in rbcL, psaA and psbA gene sequences analyses. These characteristics lead to propose the new combination of Dictyota coriacea (Homes) I.K. Hwang, H.S. Kim et W.J. Lee, comb. nov.