• Title/Summary/Keyword: Dok-do

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A new record of brown algae, Papenfussiella densa from Dok-do, Korea

  • Won, Boo Yeon
    • Korean Journal of Environmental Biology
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    • v.38 no.1
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    • pp.160-164
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    • 2020
  • Papenfussiella densa was described as Papenfussiella kuromo f. densa from Japan by Inagaki in 1958. P. densa has been recognized as an endemic and independent species based on the molecular analyses of type material without detailed morphological observations. In this study, Papenfussiella densa is reported as a new record from Dok-do, South Korea, based on morphological and molecular analyses. Papenfussiella densa is mainly characterized as having narrow, branched, slimy, and tomentose thalli with branchlets, partially hollow in the medulla of the middle part. The molecular analyses of the chloroplast rbcL-rbcS DNA sequence of the Papenfussiella densa sample from Korea revealed that it matched that of P. densa from Japan and was nested in the clade of Papenfussiella. There was only a 0.02% gene sequence divergence between the Korean and Japanese samples. We report P. densa as a new record from Korea and add this species to the list of Korean macroalgal flora.

Application of Bacteria Isolated from Dok-do for Improving Compressive Strength and Crack Remediation of Cement-sand Mortar (독도산 탄산칼슘형성세균에 의한 모르타르 균열보수와 압축강도 증진)

  • Park, Sung-Jin;Lee, Na-Young;Kim, Wha-Jung;Ghim, Sa-Youl
    • Microbiology and Biotechnology Letters
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    • v.38 no.2
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    • pp.216-221
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    • 2010
  • This study shows an application of microbiologically induced carbonate precipitate for strength improvement and crack remediation of cement-sand mortar. Seven calcium carbonate-forming bacteria (CFB) were isolated from Dok-do and partially identified by DNA sequence analysis of the 16s rRNA gene. Crystal aggregates were apparent around the bacterial colonies grown on an agar medium. These strains showed strain specific $CaCO_3$ precipitation on urea-$CaCl_2$ medium. Among 7 isolates, Arthrobacter nicotinovorans KNUC601, Microbacterium resistens KNUC602, Agrobacterium tumefaciens KNUC603, Exiguobacterium acetylicum KNUC604, and Bacillus thuringiensis KNUC606 showed a repairing of artificial forced cracks in cement-sand mortar. Compressive strength of cement-sand mortar consolidated with Stenotrophomonas maltophilia KNUC605 was increased around 14.07% compared with that of negative control.

Microbacterium elymi sp. nov., Isolated from the Rhizospheric Soil of Elymus tsukushiensis, a Plant Native to the Dokdo Islands, Republic of Korea

  • Ye-Ji Hwang;Soo-Yeong Lee;Jin-Soo Son;Jin-suk Youn;Woong Lee;Jae-Ho Shin;Mi-Hwa Lee;Sa-Youl Ghim
    • Journal of Microbiology and Biotechnology
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    • v.33 no.2
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    • pp.188-194
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    • 2023
  • Microbacterium elymi KUDC0405T was isolated from the rhizosphere of Elymus tsukushiensis from the Dokdo Islands. The KUDC0405T strain was Gram-stain-positive, non-spore forming, non-motile, and facultatively anaerobic bacteria. Strain KUDC0405T was a rod-shaped bacterium with size dimensions of 0.3-0.4 × 0.7-0.8 ㎛. Based on 16S rRNA gene sequences, KUDC0405T was most closely related to Microbacterium bovistercoris NEAU-LLET (97.8%) and Microbacterium pseudoresistens CC-5209T (97.6%). The dDDH (digital DNA-DNA hybridization) values between KUDC0405T and M. bovistercoris NEAU-LLET and M. pseudoresistens CC-5209T were below 17.3% and 17.5%, respectively. The ANI (average nucleotide identity) values among strains KUDC0405T, M. bovistercoris NEAU-LLET, and M. pseudoresistens CC-5209T were 86.6% and 80.7%, respectively. The AAI (average amino acid identity) values were 64.66% and 64.97%, respectively, between KUDC0405T and its closest related type strains. The genome contained 3,596 CDCs, three rRNAs, 46 tRNAs, and three non-coding RNAs (ncRNAs). The genomic DNA GC content was 70.4%. The polar lipids included diphosphatydilglycerol, glycolipid, phosphatydilglycerol, and unknown phospholipid, and the major fatty acids were anteiso-C17:0 and iso-C16:0. Strain KUDC0405T contained MK-12 as the major menaquinone. Based on genotypic, phylogenetic, and phenotypic properties, strain KUDC0405T should be considered a novel species within the genus Microbacterium, for which we propose the name M. elymi sp. nov., and the type strain as KUDC0405T (=KCTC 49411T, =CGMCC1.18472T).

Variability of Ocean Status around Ulleung Basin and Dok-do by using ARGO Data (무인 해양관측기 (ARGO 플로트) 자료를 이용한 울릉분지 및 독도 주변해역 해황 변동성 분석)

  • Youn, Yong-Hoon;Chang, You-Soon;Hyun, Yu-Kyung;Cho, Chang-Woo;Ku, Ja-Ok;Cho, Min-Kwang;Ban, Young-Seok;Park, Seong-Jun;Kim, Su-Jeong
    • Atmosphere
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    • v.16 no.4
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    • pp.379-385
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    • 2006
  • Meteorological Research Institute (METRI) participates the R&E (Research and Education) program of Korea Science and Engineering Foundation,"Variability of ocean status around Ulleung basin and Dok-do by using ARGO data" as a part of "Carricula development for gifted students" program. From this program, we support students to have an opportunity for handling scientific data with advanced technology and inspire their scientific interests. In this article, we introduce the training processes of this program and the results of data analysis by the students themselves.

First Record of Gobiid Fish, Astrabe fasciata (Perciformes: Gobiidae) from Dokdo, Korea (독도에서 채집된 망둑어과 어류 1미기록종, Astrabe fasciata)

  • Kim, Dong Sik;Kweon, Seon-Man;Choi, Youn
    • Korean Journal of Ichthyology
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    • v.27 no.4
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    • pp.317-320
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    • 2015
  • The one specimen of Astrabe fasciata, belonging to the family Gobiidae was collected from the Dokdo of East Sea in Korea, and described as the first record from Korea. The specimen is characterized by having two dorsal fins, pectoral fin with free rays (five upper, two lower), protrusion on upper posterior part of supraorbital dermal fold, white spots dispersed on head and five white transverse bends on the body. We proposed its Korean name "Dok-do-eol-ruk-mang-duk-sok" and "Dok-do-eol-ruk-mang-duk" for the genus and species, respectively.

A new record of Galium bungei var. miltorrhizum (Hance) Jeong & Pak (Rubiaceae) in Korea

  • Jeong, Keum Seon;Shin, Jae-Kwon;Pak, Jae-Hong;Choi, Kyung
    • Korean Journal of Plant Taxonomy
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    • v.47 no.1
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    • pp.23-26
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    • 2017
  • We reported an unrecorded plant species, Galium bungei var. miltorrhizum (Hance) Jeong & Pak in Korea. This species is found in Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongsangbuk-do, and Gyeongsangnam-do. G. bungei var. miltorrhizum is distinguished from related taxa by glabrous stem and glabrous or rarely short papillate mericarps. This taxon was named 'Dung-geun-ne-ip-gal-kwi' in Korean based on shapes of leaves. We provided a description, illustrations, photographs, and a key of related taxa in Korea. And we propose a new combination (Galium bungei var. miltorrhizum).

The Analysis of Vascular Plant Species Composition in Dok-do Island (독도 유관속 식물상과 종조성 분석)

  • Lee, Don-Hwa;Cho, Seong Ho;Pak, Jae-Hong
    • Korean Journal of Plant Taxonomy
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    • v.37 no.4
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    • pp.545-563
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    • 2007
  • The investigated vascular plants of Dok-do island were confirmed that consisted of 46 species, 1 subspecies, 1 varieties in total of 48 taxa growing spontaneously. 1 taxa of Pteridophyta, 36 taxa of Dicotyledon and 11 taxa of Monocotyledon identified. In 48 identified taxa in this study, total 13 taxa included Orobanche coerulescens Stephan, Fallopia sachalinensis (F. Schmidt) Rouse Decr., Lonicera insularis Nakai identified according to the Korean plant taxa for environmental assessment. Planting species were about 10 taxa included Pinus thunbergii Parl., Hibiscus syriacus L. and etc. Four species confirmed in this study such as between Chenopodium virgatum Thunb. and Chenopodium album L., Echinochloa crusgalli (L.) P.Beauv. and Echinochloa crusgalli var. oryzicola (Vasinger) Ohwi. were doubt on identification in taxonomic entity due to morphological characteristics. The dispersion type of Do-kdo plants were anemochore 31 taxa, zoodchore 8 taxa, hydrochore 2 taxa and the others by artificial means.

Induced of Systemic Resistance against Gray Leaf Spot in Pepper by Enterobacter Species Isolated from Family Gramineae Plants in Dok-do (독도의 벼과식물로부터 분리된 Enterobacter spp.에 의한 고추의 흰별무늬병에 대한 전신유도저항성)

  • Son, Jin-Soo;Sumayo, Marilyn;Kang, Hyun-Uk;Kim, Byung-Soo;Kwon, Duck-Kee;Ghim, Sa-Youl
    • Microbiology and Biotechnology Letters
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    • v.40 no.2
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    • pp.135-143
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    • 2012
  • This study's aim is to isolate and characterize plant growth promoting Enterobacter species for the biological control of gray leaf spot in pepper. Screening was carried out from the rhizosphere of Agropyron tsukushiensi var. transiens (Hack.) Ohwi in Dok-do. Rhizobacterial isolates were partially identified by 16S rDNA sequencing and Enterobacter species were tested for plant growth promoting capabilities and the induction of systemic resistance in pepper against gray leaf spot caused by Stemphylium solani. Isolates were tested for production of indole-acetic acid and siderophore, and for phosphate solubilization. The application of isolates was effective in controlling gray leaf spot in pepper with E. asburiae (KNUC5007) and E. cancerogenes (KNUC5008 and KNUC5010) having the highest efficacy in reducing gray leaf spot severity. This is the first report of the biological control of gray leaf spot in pepper using rhizobacteria and it is hoped that this study will increase the utilization of Enterobacter species as plant growth promoters and biocontrol agents.

Investigation of Soil Characteristics and Landslides Probability in East Island of Dok-Do (독도 동도지역의 토질특성 및 산사태가능성 조사)

  • Song, Young-Suk;Chae, Byung-Gon;Cho, Yong-Chan;Lee, Choon-Oh
    • The Journal of Engineering Geology
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    • v.17 no.4
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    • pp.665-671
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    • 2007
  • In this study, the soil characteristics and the landslide probability are investigated in East Island of Dok-do. The distribution and depth of soil layer were investigated and the soil samples were taken from the soil layer in East Island. As the results of field investigation, the soil layer was partly distributed in specific location and the soil depth was ranged from 1cm to 50cm. Also, the soil depth was mainly ranged about 10cm in the large part of soil layer. The soils were classed as the weathered residual soils and involved many organic contents such as rotten roots and leaves. The average of water contents is 23.2%, and the average of liquid limits is 42.2%. Also, the soils is non-plastic condition. Also, the soils were mainly classed as the poor graded sand including loam contents. Meanwhile, the landslide probability was investigated through a survey of the soil layer distribution in East Island. The soil depth was very shallow in the large part of the soil layer, and the distribution area of soil layer was small. Therefore, it may predict that the landslide probability is very low due to the dissatisfaction of landslide occurrence condition.