• ALGAE
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• v.21 no.2
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• pp.175-183
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• 2006

Recent phylogenetic studies of scytosiphonacean brown algae show many conflicts with current classification. In order to clearly define the phylogenetic relationships of the family, we newly sequenced the photosystem I coding psaA gene (1488 base pairs) from 13 taxa (15 samples), of the family, and, for comparison, rbcL from four taxa. The psaA region has more informative sites (17.9%) than the rbcL (13.1%) and the number of nodes supported by over 50% bootstrap values is more in the psaA phylogeny (53 /57 nodes; 93%) than in the rbcL (47/63 nodes; 74.6%). The psaA phylogenies are basically congruent with the rbcL trees, recognizing two major groups in the monophyletic Scytosiphonaceae. The first group included Myelophycus, Petalonia, Scytosiphon, and elongate sack-shaped species of Colpomenia, primarily cold temperate elements with unilocular zoidangia on sporophytes. The second group, although not resolved, consisted of Hydroclathrus, Chnoospora, Rosenvingea, and ball-shaped Colpomenia, primarily warm-temperate taxa with both unilocular and plurilocular zoidangia on sporophytes. Chnoospora is not monophyletic, as was previously shown the paraphyly of Colpomenia, Petalonia, and Scytosiphon. Hydroclathrus clathratus from Korea and Japan was not monophyletic. Our studies show that gametophytic characters are the main source of conflict for the present taxonomy of the family. The psaA region is a useful tool for resolution of phylogenetic relationships within the Scytosiphonaceae.

• ALGAE
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• v.39 no.2
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• pp.97-108
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• 2024

The Ralfsiaceae family, part of the Ralfsiales order and consisting of crustose brown algae, includes five genera: Analipus, Endoplura, Fissipedicella, Heteroralfsia, and Ralfsia. In this study, a novel crustose genus named Ramipedicella gen. nov. is introduced within the Ralfsiaceae based on molecular and morphological analyses. Phylogenetic analyses using both concatenated dataset (rbcL + COI-5P genes) and rbcL indicate that the crustose brown algae that we collected from Korea and Russia form a unique grouping within the Ralfsiaceae. This grouping is strongly supported by both bootstrap analysis and Bayesian posterior probabilities. The genetic differences in the rbcL and COI-5P sequences between Ramipedicella and other genera within Ralfsiaceae range from 6.7 to 9.3% for rbcL and from 15.5 to 20.8% for COI-5P. Ramipedicella is characterized by crustose thalli having new crusts growing on top of old ones with a hypothallial basal layer and erect perithallial filaments, long cells with width-to-length ratio of 1 : 1-16, single chloroplast per cell, plurangia with one to several sterile cells, one to several unangia produced from unicellular stalks or from the lateral-basal region to the paraphyses, and unangia arising sequencially in irregularly branched specialized filaments. Ramipedicella, the recently identified genus, comprises two distinct species. Ramipedicella miniloba, the type species, is distinguished by crusts with small lobes, numerous hair tufts, plurangia terminated by 1-4 sterile cells, and large oblong unangia. Ramipedicella longicellularis is identified by generally smooth crusts, absence of phaeophycean hairs, plurangia terminated by 1-2 apical sterile cells, and smaller mostly oblanceolate unangia.

• ALGAE
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• v.21 no.4
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• pp.463-470
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• 2006

Studies have been made of the species composition and variation of benthic marine algae at subtidal zone of Uljin on the east coast of Korea. Destructive method was employed to measure biomass over four seasons (2000-2002). Of 87 marine algae species identified, 11 were Chlorophyta, 29 were Phaeophyta and 47 were Rhodophyta. Dominant species in biomass were Ulva pertusa, Undaria pinnatifida and Sargassum piluliferum in summer, Laminaria religiosa, Sargassum fulvellum and Gigartina tenella in autumn, Codium fragile, Undaria pinnatifida, Sargassum horneri, S. piluliferum and S. ringgoldianum in winter, and Undaria pinnatifida, Dictyopteris divaricata, Sargassum confusum and S. horneri in spring. In general, green algae (Ulva pertusa, Codium fragile) and brown algae (Undaria pinnatifida, Sargassum fulvellum, S. horneri, S. piluliferum) appeared predominantly in the 3, 6 m depths and red algae (Gelidium amansii, Plocamium telfairiae) in the 9, 12 m depths. The barren ground of the rocky shore might provide the decrease of benthic marine algae biomass and species.

• The Korea Genome Conference
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• 2005.09a
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• pp.37-37
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• 2005

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.2
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• pp.106-112
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• 2022

As a series of basic research to draw the pilot design measures for developing the habitat apparatus of Sulculus diversicolor supertexta inhabiting the coastal area of Jeju island, this study conducted a water tank experiment to understand the habitat marine environment of Sulculus diversicolor supertexta and the preference of habitat space focusing on the research fisheries performing the discharge of marine products. In the composition degree of marine algae in both fisheries, Donggwi-ri showed the highest gulfweed (79.3%) as brown algae and there were some coralline algae (17.2%) as red algae. Hansu-ri yielded the highest gulfweed (48.1%) as brown algae, which was followed by sea lettuce (10.4%) as green algae. In the preference of habitat space, the shelter angles 40° showed the highest adhesion as number of 82.9, which was followed by 60° and 70° as 69.2 and 68.2 respectively (P<0.05) by reviewing the environmental characteristics of habit of Salculus diversicolor supertexta in the coastal fishery of Jeju Island, when considering the adhesion rate in each of five shelters with different angles. In the future, there should be continuous research and monitoring for designing the fish shelters suitable for the coastal fisheries of Jeju island, and it would be also necessary to add the field-centered sustainable concrete research.

• Journal of Environmental Science International
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• v.22 no.6
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• pp.761-771
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• 2013

The species composition and variation of marine plants at Saguenjin in the east coast of Korea were investigated monthly from October 2008 to December 2009. As a result, 92 species of marine plants identified, 91 species were seaweeds (7 green algae, 22 brown algae, 62 red algae) and 1 were sea grass. Dominant species in importance value were melobesioidean algae, Ulva pertusa and Phyllospadix iwatensis. The vertical distribution of algae were characterized by melobesioidean algae, U. pertusa at 3 m depth, melobesioidean algae, P. iwatensis and U. pertusa at 5 m depth and melobesioidean algae, Chondrus ocellatus and Prionitis cornea at 10 m depth.

• ALGAE
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• v.27 no.2
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• pp.125-134
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• 2012

Germanium dioxide ($GeO_2$) has been used for many years in the cultivation of red and green algae as a means of controlling the growth of diatoms. Brown algae are sensitive to $GeO_2$, however, the basis of this sensitivity has not been characterized. Here we use embryos of $Fucus$ $vesiculosus$ to investigate morphological and physiological impacts of $GeO_2$ toxicity. Morphometric features of embryos were measured microscopically, and physiological features were determined using pulse amplitude modulated (PAM) fluorometry. At 5 mg $L^{-1}$ $GeO_2$, embryos grew slower than controls and developed growth abnormalities. After 24 h, initial zygote divisions were often oblique rather than transverse. Rhizoids had inflated tips in $GeO_2$ and were less branched, and apical hairs were deformed, with irregularly aligned, spheroidal cells. Minimum fluorescence ($F_0$) showed minor differences over the 10 days experiment, and pigment levels (chlorophylls $a$, $c$ and total carotenoids) showed no difference after 10 days. Optimum quantum yield increased from ca. 0.52 at 24 h to 0.67 at 5 days, and $GeO_2$-treated embryos had higher mean values (significant at 3 and 5 days). Optimum quantum yield of photosystem II (${\Phi}_{PSII}$) was stable in control thalli after 5 days, but declined significantly in $GeO_2$. Addition of silica (as $SiO_2$) did not reverse the effects of $GeO_2$. These results suggest that $GeO_2$ toxicity in brown algae is associated with negative impacts at the cytological level rather than metabolic impacts associated with photosynthesis.

• Mycobiology
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• v.51 no.6
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• pp.401-409
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• 2023

Nigrospora (Xylariales, Apiosporaceae) consists of species of terrestrial plant endophytes and pathogens. Nigrospora has also been reported in marine environments such as mangroves, sea fans, and macroalgae. However, limited research has been conducted on Nigrospora associated with macroalgae. Here, we isolated Nigrospora species from three types of algae (brown, green, and red algae) from Korean islands (Chuja, Jeju, and Ulleung) based on phylogenetic analyses of multigenetic markers: the internal transcribed spacers (ITS), beta-tubulin (BenA), and translation elongation factor 1 (TEF1-α). A total of 17 Nigrospora strains were isolated from macroalgae and identified as nine distinct species. The majority of Nigrospora species (seven) were found on brown algae, followed by red algae (three), and then green algae (two). To our understanding, this study represents the first account of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, N. osmanthi, N. pyriformis, and N. rubi occurring in marine environments. Additionally, this study provides the first report of the occurrence of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, and N. osmanthi in South Korea. This study will provide valuable insights for future research exploring the functions of fungi in macroalgal communities.

• ALGAE
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• v.27 no.1
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• pp.21-32
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• 2012

We report an oxidative burst triggered by prostaglandin $A_2(PGA_2)$ in the brown algal kelp Laminaria digitata, constituting the first such discovery in an alga and the second finding of an oxidative burst triggered by a prostaglandin in a living organism. The response is more powerful than the oxidative burst triggered by most other chemical elicitors in Laminaria. Also, it is dose-dependent and cannot be inhibited by diphenylene iodonium, suggesting that another source than NAD(P)H oxidase is operational in the production of reactive oxygen species. Despite the very strong oxidative response, rather few effects at other levels of signal transduction pathways could be identified. $PGA_2$ does not increase lipolysis (free fatty acids) in Laminaria, and only one oxylipin (15-hydroxyeicosatetraenoic acid; 15-HETE) was found to be upregulated in Laminaria. In a subsequent set of experiments in the genome model Ectocarpus siliculosus, none of 5 selected candidate genes, all established participants in various stress responses, showed any significant differences in their expression profiles.

• ALGAE
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• v.18 no.4
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• pp.349-354
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• 2003

This paper reports that the heavy metal accumulation in marine seaweeds. Algal samples collected from Korean coast were analyzed to determine the concentrations of Cu, Cd, Cr, Zn and Pb. In general, heavy metals were found to be concentrated in many kinds of Korean seaweeds. The concentration levels of accumulated heavy metals in the marine seaweeds was in the following order: Zn > Cu > Cr > Pb > Cd. The concentrations of the heavy metals in the seawater were the highest in Iyajin harbor. Sargassum horneri, a brown alga accumulated high concentrations of Cu (80.66 ${\mu}g{\cdot}g^{-1}$ dw) and Cr (31.54 ${\mu}g{\cdot}g^{-1}$ dw). The high concentrations of heavy metals were accumulated in the brown algae.