• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.135-144
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• 2013

Blue-green algae blooms occurred during early winter in the North-Han River, Korea. Among blue-green algae, Anabaena spiroides were observed for approximately 33 consecutive days, between 28 November and 30 December, 2011. A. spiroides emerged from Lake Uiam to Lake Paldang, depending on the flow of the river has spread downstream. Changes of physical water environment like rising water temperature and increasing hydraulic retention time influenced the A. spiroides bloom. The A. spiroides bloom showed a very rapid increase in cell density, and a slow decrease: the cell density increased to a maximum of $11,325cells\;mL^{-1}$ in Lake Paldang (st. 5), and was completely disappeared after the water temperature dropped below $4^{\circ}C$. A decrease in water temperature was the most influential factor among all environmental parameters, for the reduction of A. spiroides cell density. The A. spiroides bloom was accompanied with the occurrence of very high concentrations of the odor metabolite geosmin. Geosmin reached the peak value of $1,640ng\;L^{-1}$ in Lake Paldang (st. 4). The geosmin concentration was very strongly correlated with cell numbers of A. spiroides.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.340-344
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• 2007

Avian influenza viruses cause a considerable threat to humans and animals. In this study, we investigated whether alkaline disinfectant solution can inactivate H5N1, H3N2, H6N1, and H9N2 subtypes of avian influenza virus. When H5N1, H3N2, H6N1, and H9N2 avian influenza viruses were treated with alkaline solution diluted with PBS (pH 7.2) prior to infection into MDCK cells, alkaline disinfectant solution (at dilutions up to $10^{-2}$) completely inactivated all avian influenza subtypes tested. To confirm the inactivation of avian influenza viruses by alkaline disinfectant solution, we used an immunofluorescence assay with influenza A anti-nucleoprotein antibody and FITC-labeled secondary antibody to stain MDCK cells infected with avian H9N2 influenza viruses. No staining was observed in MDCK rells infected with H9N2 viruses that were pre-treated with a $10^{-2}$ dilution of alkaline disinfectant solution, while strong staining was observed in MDCK cells infected with H9N2 viruses without pre-treatment. Our results indicate that alkaline solution could help to control avian influenza viruses including the highly pathogenic H5N1 subtype.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.198-203
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• 1993

The cyst of Scrippsiella trochoidea from the surface mud in Masan Bay was germinated in the incubator for the culture. This species was one of dinoflagellates responsible for the early spring bloom in the southern coastal water of Korea. The culture experiments were carried out under the various gradients of environmental factors to know their effects on the population growth of this dinoflagellate. With respect to the effects of environmental factors on the growth, it was proved that the maximum cell growth was occurred at 4,000 lux of light intensity, salinity $30\%0$ and temperature $20^{\circ}C$. When 0.25ml/ml of the filtrates of Skeletonema costatum culture medium and the supernatants of soil extracts were added to growth medium as organic growth stimulants, both materials enhanced the population growth. In the fatty acid composition of S. trochoidea, $C_{16:0}$ was the major component, and $C_{18:0},\;C_{18:1},\;C_{22:0}\;and\;C_{22:1}$ were a minor components.

• Proceedings of the Korean Aquaculture Society Conference
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• 2001.12a
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• pp.240-241
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• 2001

• Korean Journal of Ecology and Environment
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• v.47 no.1
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• pp.1-12
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• 2014

Some blue-green algal species such as those in the genus Anabaena causing severe algal blooms can produce akinetes, resting spores, in aquatic ecosystems. Germinated akinetes staying in the sediment as "seed banks" grow into vegetative cells under favorable conditions of light intensity, nutrient, and temperature. Therefore, akinete plays an important role in forming the nuisance bloom. However, little information is available in the ecological study of akinetes compared to that of vegetative cells in Korea. This review reports ecological and physiological characteristics of akinetes, especially of the blue-green algal genus Anabaena. We also suggest the feasible area of akinetes in the freshwater ecosystems. We expect that the suggested studies associated with akinetes will contribute to further understanding the life cycle and ecology of Anabaena and other algae.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.199-200
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• 2001

해조류중 특히 방사무늬 김 (Porphyra yezoensis)의 양식기술은 인공채묘기술이 개발된 이래 양식 및 가공분야의 많은 기술적 진보를 거듭해 오고있으며 양식장은 천해 해역으로 하천수의 유입으로 인한 풍부한 영양염류의 공급을 받고있는 지역에 있다. 이러한 영양염류는 김의 생장촉진에 도움을 주는 반면에 여러 가지 미생물, 미세조류, 부착조류 등의 증식도 함께 촉진하여 결과적으로 김 성장에 대한 영양분의 경쟁관계, 질병유발 김 양식의 생산력 저하등의 문제점들을 동시에 유발하고 있다. (중략)

• Journal of Life Science
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• v.28 no.3
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• pp.345-350
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• 2018

This study examines the role of six species of microalgae, including Phaeodacylum tricrnutum (PT), Chaetoceros gracilis (CG), Nanochloris oculata (NO), Pavlova lutheri (PL), Chlorella ellipsoidae (CE), and Scendedemus obliquus (SO), on hair loss prevention and scalp improvement. To determine the effects of microalgae extracts on hair loss prevention and scalp improvement, antioxidant activity, cell proliferation in HaCaT cells and HFDPC cells, and the inhibition level of 5-alpha reductase activity were examined. In the study of antioxidant activity, the $EC_{50}$ values of DPPH anti-radical activities indicated that the SO, CG, and ST9 treatment groups demonstrate significant antioxidant activity. In the study of the hydroxyl radical scavenging activity, CG (6.6~42.1%), ST9 (26.0~44.0%), and SO (7.8~44.3%) demonstrated significant effects. Furthermore, SO promoted the proliferation of HaCaT cells and a human epidermal cell line during a 6-day treatment. In the study of the proliferation of HFDPC cells, a hair follicle dermal papilla cell line, CG, and SO significantly stimulated cell proliferation. Finally, PT, CG, and SO significantly inhibited 5-alpha reductase activity. These results suggest that among the six microalgae used in this study, CG and SO have antioxidant effects, induce cell proliferation, inhibit 5-alpha reductase activity, and can be used for hair loss prevention and scalp improvement.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.137-138
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• 2002

최근 세균을 이용한 적조 방제연구가 활발히 진행되면서 해양에서 다수의 미세조류 저해균이 분리되고 있다. 전보에서 저자들은 규조류 Chaetoceros spp.의 생육을 저해하는 해양세균 Shewanella sp. SR-14를 분리하였으며, 이 균은 대사산물을 생성하여 그 생육을 저해하는 것으로 보고한 바 있다. 그런데 Shewanella sp. SR-14에 의한 Chaetoceros calcitrans의 생육저해는 대사산물(배양여액)만을 사용한 경우보다 세균이 공존하는 경우에 그 활성이 휠씬 강하여 세균이 생성하는 저해물질에 의한 것으로만 이해하기 어려웠으며, 다른 미지의 기구가 관여하고 있을 가능성이 시사되었다. (중략)

• Korean Journal of Ecology and Environment
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• v.55 no.2
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• pp.111-119
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• 2022

The occurrence of cyanobacterial blooming and the contaminant sources were analyzed in the downstream of Jecheon Stream, a tributary of Chungju Reservoir. The concentrations of chlorophyll a at the Myungseo Fishing Point (GPS; 37°03'25.5"N, 128°03'13.6"E) were 399.2 and 184.8 mg m^-3 on October 18, 2015 and September 25, 2016, respectively, and the concentrations of total microcystins, a cyanobacterial toxin mainly produced by Microcystis, were 124.09 and 79.71 ㎍ L^-1, respectively. The occurrence of cyanobacterial blooming at the downstream of Jecheon Stream was closely related to the water level of Chungju Reservoir. The cyanobacterial blooming occurred after the increase of water level in Chungju Reservoir, when the water body stagnated. As a result of analyzing National Water Quality Monitoring Data of the upper region of Jecheon Stream, the main source of pollutant was Jangpyeong Stream, the tributary of Jecheon Stream, and the discharge water from Jecheon Wastewater Treatment Plant located in Jangpyeong Stream was considered to be the most important source of contaminant.

• Journal of Wetlands Research
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• v.15 no.1
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• pp.79-90
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• 2013

Stormwater wetland targeted to treat the rainfall runoff from cow feeding-lot basin has been monitored from May 2010 to November 2011. Reduction efficiency estimated based on 20 rainfall event monitoring was 88%, 54%, 70%, 31%, and 64% for TSS, BOD, $COD_{Cr}$, TN, and TP, respectively. Theoretically, as rainfall depth increases, hydraulic exchange ratio has to be increased. When the exchange ratio approaches to 1 (usually design goal), TSS reduction efficiency was estimated about 55%. Uncertainty in reduction efficiency of the stormwater wetland is normally very high due to the continuous rainfall activity, its magnitude and intensity, antecedent dry days, and other natural variables which can not be controlled by experiment conductors. In this study, predominant affecting variables was found to be hydraulics caused by consecutive rainfall events having different intensity and algal growth during dry days.