• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.3
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• pp.248-262
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• 2021

Marine planktonic ciliates include two major groups, loricated tintinnids and naked oligotrichs. The study of marine ciliate plankton in Korea began with taxonomic efforts on tintinnids based on the morphology of lorica, a vase-shaped shell. Despite polymorphism in the lorica, it is utilized as a key characteristic in identification of tintinnid species. However, oligotrichs have been studied only recently in Korea due to challenges associated with the observation of ciliary arrangements and the technical development for cell staining. Species diversity and phylogenetic classification of the ciliates have been informed by recent advances in morphological and molecular analyses. Illustrations of the planktonic ciliate in Korea have been published on the basis of taxonomic data of tintinnids and oligotrichs. Planktonic ciliates acting as the major consumers of pico- and nanoplankton as well as the prey of mesozooplankton, has been monitored by spatial and temporal investigations in Korean coastal waters. A practical approach addressing the limitations and potential of marine ciliate studies in Korea is proposed here to improve the data quality of planktonic ciliates, providing an enhanced basis for quality control of ciliate monitoring.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.39-50
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• 2024

In ecosystems within limited resources, interspecific competition is inevitable, often leading to the competitive exclusion of inferior species. This study aims to provide foundational information for the conservation and restoration management of Microphysogobio rapidus by evaluating species' ecological response to biological factors within its habitat. To understand this relationship, we collected food web organisms from site where M. rapidus coexist with Microphysogobio yaluensis, a specie ecologically similar to M. rapidus, and evaluated the trophic levels (TL), isotopic niche space (INS), and the overlap of INS among fishes within the habitat using stable isotope analysis. Our analysis revealed that the M. rapidus exhibited a higher TL than M. yaluensis, with TL of 2.6 and 2.4, respectively. M. yaluensis exhibited a broad INS, significantly influencing the feeding characteristics of most fish. Conversely, M. rapidus showed a narrow INS and asymmetric feeding relationships with other species, in habitats with high competition levels. This feeding characteristics of M. rapidus indicate that the increase in competitors sharing the similar resources lead to a decrease in available resources and, consequently, is expected to result in a decrease in their density.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.26-27
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• 2018

With entry into force of the Nagoya Protocol to promote the fair sharing of the benefits of accessing and utilizing genetic resources, much support has been given to research on the development of biomaterials and products using domestic natural resources. Conservation and resource-saving of native species became very important through Nagoya Protocol enactment. The trend of cosmetic industry has been shifing from use synthetic chemicals to natural biomaterials, due to the safety regulations on new materials, ban on animal experiments, and expansion of cosmeceuticals range. In addition, functional cosmetic range has been expanded from whitening, wrinkle improvement, and ultraviolet shielding, to hair loss, hair loss alleviation, acne relaxation, and moisturizing of atopic skin, thus causing the activation of research about field of efficacy evaluation on natural biomaterials and commercialization. Chungbuk province is fostering the bio industry as a key industry for regional economic growth. For this purpose, Osong Biotechnology Complex/Ochang Science Industrial Complex in middle area, Jecheon biovalley in northern region, and Chungju Enterprise city have been established, thus playing a pivotal role in Bio innovative cluster in Korea. In particular, it was established the osong cosmetics clinical research support center to develop the cosmetics industry in chungbuk, thereby supporting clinical trials, efficacy evaluations, overseas certification, and overseas market entry in order to advance into the global market. In addition, oriental plants such as astragalus propinquus, schisandra chinensis, eucommia, alpiniae oxyphyllae fructus and biancaea sappan are being actively studied as global cosmetic ingredients through the promotion of various national research and development projects using natural materials in chungbuk province. The chungbuk natural product industry is expected to grow further throughout cosmetics industry development in the future, as companies and research institutes are actively promoting the secure index of effective material in natural products and effective material commercialization.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.5-5
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• 2019

DMZ는 살아있는 생물다양성의 보고로 지난 60여년동안 자연적으로 재생이 일어나고 환경적인 강제 보존 영향으로 높은 생태학적인 가치가 유지되고 있으며, 최근에는 남북교류에 대한 활발한 의지로 DMZ생태자원의 남북공동활용 방안에 대한 이슈가 급부상하고 있다. 이에 본 연구진은 3년전부터 DMZ에서 자생하는 식물에 대한 조사를 진행하여 총 200여종 이상의 자생식물의 표본과 추출물들을 보유하고 있으며, 이 추출물들을 활용 in vitro 와 in vivo 평가를 통해 비임상 평가에서 유효한 효과를 나타내는 후보물질들을 다수 찾아낼 수 있었다. 그 중 조팝나무(Spiraea prunifolia var. simpliciflora)는 쌍떡잎식물 장미과에 속하는 낙엽활엽관목으로 동북아시아 지역에 널리 분포되며 우리나라에서는 중부지방에 주로 서식한다고 알려져 있다. 예로부터 해열 및 소염, 신경통완화 치료등에 이용해왔다고 알려져 있으며 그 속에는 다양한 terpenoids, flavonoid 및 phenolic 화합물이 다량 함유되어 있다고 알려져 있다. 본 연구에서는 조팝나무 추출물을 이용하여 전구지방세포에서의 지방세포분화 억제 및 관련 유전자들의 활성을 확인한 후 고지방식이로 유도된 high-fat diet mouse model을 이용하여 체지방 감소 및 내장지방감소, 간 조직내의 지방량 감소등을 확인하였으며, 혈액분석을 통해 총콜레스테롤과 고중성지방등 동맥경화와 심혈관계 질환을 유도시킬수 있는 지표들에서 억제 활성도 확인하였다. 특히 내장 지방의 경우는 Micro-CT를 통해 정밀한 분석을 진행하였고, 체지방뿐만 아니라 전체 체중감소도 나타나는 것을 확인하였다. 현재 실험을 통해 적출된 간 조직과 지방조직을 이용하여 항 비만 활성의 작용기전을 지속적으로 확인하고 있으며, 이 결과는 국제적인 연구저널에 보고되어 향후 체지방 감소 또는 항 비만 치료제로 개발되는 비임상 연구자료로 활용될 계획이다. 이미 조팝나무에 대한 연구결과는 특허로 출원이 완료되어 PCT출원까지 진행중에 있으며 개별인정형 건강기능식품 개발 기업에 기술이전이 될 예정이다. 또한 원활한 원료 수급을 위해 기초단체 소속 농업기술센터와 원료 재배 및 대량 수급에 관한 논의를 마친 상태로 접경지역 근처 농가소득 증대로도 이어지는 제품화 사례이기도 하다. 이는 접경지역에서 자생하는 원료의 활성을 과학적으로 검증하여 기업과의 연계를 통해 기초시군 단체의 농가 소득과도 연계한 우수한 제품개발 사례로 향후에도 이와 같은 연구성과가 지속적으로 도출되기를 기대해본다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.2
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• pp.103-125
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• 2022

This study aims to identify the community characteristics of meiofauna inhabiting the Yellow Sea continental shelf. To this end an annual survey was conducted considering the seasons from 2018 to 2020 at 13 stations with a depth of 18~90 m of the Yellow Sea located at latitudes 35, 36 and 37 degrees north latitude. The survey was conducted in three seasons of spring, summer, and autumn at 5 stations in October 2018, 9 stations in April 2019, and 6 stations in August 2020 was used to collect 3 repetitions at each station. The habitat density of meiobenthos in the surveyed area was in the range of 45~1029 inds./10 cm², which was similar to the previous studies conducted in the Yellow Sea. The density of meiobenthos according to the seasons was 800±69 inds./10 cm² in autumn, the highest, and the lowest at 260±48 inds./10 cm² in summer. A total of 19 taxa appeared in meiobenthos, and the average value showed the number of nine taxa. Among the appearing taxa, the most dominant taxon was nematodes, accounting for 80.8% of the total density, followed by benthic copepods (8.8%) and benthic foraminifers (4.7%). As for the size distribution of medium benthic animals, the density of organisms corresponding to the size of 63~125 ㎛ was the highest, and 1~0.5 mm was the lowest. As for the vertical distribution in the sediments of medium benthic animals, the habitat density gradually decreased as the depth increased in the sediment surface layer. As a result of analysis of the N/C ratio, MPI, and ITD index using medium-sized benthic animals to identify the benthic environment, there were differences by season, but no values indicating pollution overall.

• Journal of Dairy Science and Biotechnology
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• v.38 no.2
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• pp.89-98
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• 2020

The purpose of this study was to investigate the probiotic properties of lactic acid bacteria (LAB) isolated from a Korean traditional food kimchi. Gram staining was performed by Macrogen (Macrogen, Inc.) for identification of the LAB. Five strains of LAB were identified, including DKGF9 (Lactobacillus plantarum), DKGF1 (L. paracasei ), DKGF8 (L. casei ), DK207 (L. casei ), and DK211 (L. casei ). The biological activities of the isolated strains were assessed. The results showed that heat resistance of the strains was similar to or higher than the commercial strain L. acidophilus LA-5. Indirect testing of the ability of the strains to attach to the mucin layer revealed that DKGF9, DKGF1, and DKGF8 have high binding affinities for the mucous layer. All strains showed antimicrobial activity similar to or higher than the commercial strain LA-5. In proteolysis experiments, the diameters of proteolysis zones of the five strains increased in the period of 24-72 h, with DKGF1 exhibiting the largest zone diameter. Three strains were selected based on their antioxidant activities. Among the five isolated strains, L. paracasei DKGF1 showed potential probiotic activity, and thus, it may be useful for the development of health-promoting products.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.290-300
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• 2022

A strain of Alexandrium species was established by isolating cells from Jangmok Bay, Korea. Its morphology and molecular phylogeny based on LSU rRNA gene sequences were examined. In addition, growth responses of this Alexandrium species to changes in temperature, salinity, and nutrient concentrations were investigated. This Alexandrium species from Jangmok Bay had a ventral pore on the 1', which was morphologically consistent with previously described Alexandrium tamarense and A. catenella. Phylogenetic analyses revealed that this isolate was assigned to A. pacificum (Group IV) within A. tamarense species complex. In growth experiments, relatively high growth rates and cell densities of A. pacificum (Group IV) were observed at 15℃ and 20℃. This species also grew under a wide range of salinity. This indicates that this Korean isolate of A. pacificum (Group IV) is a stenothermic and euryhaline species. In growth responses to changes in nutrient levels, enhanced growth rates and cell densities of A. pacificum(Group IV) were observed with additions of nitrate and phosphate. In particular, rapid uptakes of phosphate by A. pacificum (Group IV) were observed in experimental treatments, indicating that the increase in phosphate concentration could stimulate the growth of A. pacificum(Group IV).

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.387-397
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• 2022

The germination characteristics of the resting cysts of Pheopolykrikos hartmannii collected from the southern coastal sediments of Korea were studied at different temperature conditions, and the morphology and phylogeny of the germlings were examined. The resting cysts of Ph. hartmannii were round and characterized by a red accumulation body and many arrow-like spines and could germinate at temperature of 10 to 30℃. High germination rates (>90%) were observed at 15 and 20℃, indicating that the resting cysts could act as seed populations for the bloom initiation of Ph. hartmannii in Korean coastal waters in early summer or early fall. The morphology of the germlings was generally consistent with the previous description, and an apical groove characterized by a fully enclosed loop was observed. Phylogenetic analysis based on large SubUnit (LSU) rRNA gene sequences revealed that the germlings shared an identical sequence with the Korean and American isolates of Ph. hartmannii and was a sister clade of Polykrikos species.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.18-29
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• 2019

ROV surveys were conducted using 500 meter mini class ROV with HD video camera, 2 LED lights, a simple manipulator and 8 thrusters near the Dokdo and Simheungtaek seamount. Total six dives have been conducted using the ROV "V8 SII" from Sweden and ROV's support ship, "KOSAL V" at 4 stations between 45 and 370 meters with diving time ranged from 30 to 120 minutes. Dense communities of sea anemone (Actinostolidae sp.) and ophiuroids (Ophiuridae sp.) on the surface of rocky bottom and snow crab on the soft bottom with muddy-sand were observed at northwestern part of Simheungtaek seamount. We obtained the following results 1) habitats information for snow crab, one of the major fisheries resources, and deep-sea fauna, 2) observation on the specific topography and sediment conditions, 3) observation of the seabed surface covered with the discarded fishing gears. This study represents the first report of in situ visual observation of deep-sea organisms and their habitats near the Dokdo slopes and flat top of the Simheungtaek seamount in the East Sea. These results indicated that immediate oceanographic survey using the mini class ROV is available in the East Sea.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.4
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• pp.23-33
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• 2020

Marine algae(Macro algae) are easily bio-degradable, and by-products are available as feed and fertilizer. The biomass of marine algae has higher CO2 absorption capacity than the wood system, and is highly valuable in use due to its fast growth speed and wide cultivation area without special cost for raw material production. In 2018, Marine algae production was 1,722,486ton, such as Saccharina japonica, Undaria pinnatifida and Porphyra tenera, the large amounts of by-products have been generated in the food processing facilities for commercialization. In this study, Saccharina japonica, Undaria pinnatifida were collected in the south coast region and Porphyra tenera was collected in the west coast region. The theoretical methane potential and biochemical methane potential(BMP) were analyzed, and Modified Gompertz model and Parallel first order kinetics model were adopted for the interpretation of the cumulative methane production curves. The theoretical methane potential of Saccharina japonica, Undaria pinnatifida and Porphyra tenera were 0.393, 0.373 and 0.435 N㎥/kg-VS, respectively. BMP obtained by the Modified gompertz model 0.226, 0.227, and 0.241 N㎥/kg-VS for Saccharina japonica, Undaria pinnatifida and Porphyra tenera, respectively. And BMP obtained by the Parallel first order kinetics model were 0.220, 0.243, and 0.240 N㎥/kg-VS for Saccharina japonica, Undaria pinnatifida and Porphyra tenera, respectively.