• Economic and Environmental Geology
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• v.33 no.6
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• pp.505-517
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• 2000

This study was undertaken to provide a drinking water quality on the basis of physicochemical properties. In this study, the 25 samples of supply waters of the Taejon area were sampled twice (February and August in 1999). Hydrochemistry of the supply water belongs to the $Ca^{2＋}$-${HCO_3}^{-1}$ type, whereas the supply water was characterized by the relatively significant enrichment of ${Ca}^{2+}$, ${Na}^{2+}$, ${K}^{2+}$, ${Cl}^{2+}$ ions and heavy metals compared to the original water from the Daecheong lake. Generally, the supply water has a mean values for $10.7^{\circ}C$ of temperature, 6.86 of pH, -12 mV of Eh, 88 ${\mu}S$/cm of EC and 70.379 mg/l of TDS in February, whereas the waters of the same sites in August are a slightly high temperature ($26.1^{\circ}C$), TDS (78.069 mg/l) and extremely high EC (442 ${\mu}S$/cm) value. These values are similar with physicochemical properties of the original lake water depending on the seasonal differences. Results of speciation calculation indicate that potentially toxic ions might exist mainly in the forms of free metal (${Cu}^{2+}$ or ${Zn}^{2+}$) and a small amount of ${CO_3}^{2-}$and ${OH}^{-}$in the supply water. The water seemed to be in equilibrium with kaolinite field of the normal stability diagrams for the natural water. Based on enrichment parameter of the supply water normalized by original lake water composition, the average value of those parameter can be calculated with nearly 1.00, but the those values for Cu＋Zn possible source of decrepit pipe lines are 126.75 in February and 115.63 in August samples. The parameter values varied with sampling sites, however, do not exceed by chemistry of drinking water standard. Solid compounds remained on the membrane filter papers after filtration are adhered to pale yellow or yellowish brown colored dissolved solids and precipitates, which are coated by 0.02 to 0.35 mm thick per 500 ml with colloidal particles of about 1 to 2${\mu}m$ size. The particles are mainly Fe-Cu-Zn compounds and partly detected to Mn and Pb.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.9-15
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• 2017

Cichorium intybus L. (chicory) roots and leaves are widely used in herbal preparations, which have beneficial effects on the stimulation of digestion and metabolism of food ingredients, gastric juice excretion, diuretic action, and bile excretion. Notably, chicory root is well known as a source of polyphenols, compounds with recognized value in health improvement. In this study, we examined the physicochemical characteristics (TA, pH, and sensory evaluation) of bioactive yoghurt containing different concentrations of chicory. With increasing incubation time (5 h), the TA of the yoghurt increased whereas the pH decreased, regardless of the amount of chicory. As the amount of chicory increased, the scores for color, flavor, taste, and overall acceptability generally decreased. Among the tested groups, yoghurt with the addition of 1% chicory attained the highest scores. Further studies on the production of bioactive yogurt with optimum chicory concentration are needed.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.160-167
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• 2018

The role played by reservoirs in the biogeochemical cycles of elements is a subject of ongoing debate. Recent research has revealed that reservoirs emit significant levels of greenhouse gases. To assess the importance of reservoirs in monsoon climate areas as a source of methane gas into the atmosphere, we investigated variations in organic carbon (OC) input into the reservoir, oxic state changes, and finally the amount of methane emitted (focusing on the ebullition pathway) in Lake Soyang, which is the largest reservoir in South Korea. Total organic carbon (TOC) concentrations were higher during summer after two years of heavy rainfall. The sedimentation rates of particulate organic carbon (POC) and particulate organic nitrogen (PON) were higher in the epilimnion and hypolimnion than the metalimnioin, indicating that autochthonous and allochthonous carbon made separate contributions to the TOC. During stratification, oxygen depletion occurred in the hypolimnion due to the decomposition of organic matter. Under these conditions, $H_2S$ and $CH_4$ can be released from sediment. The methane emissions from the reservoir were much higher than from other natural lakes. However, the temporal and spatial variations of methane ebullition were huge, and were clearly dependent on many factors. Therefore, more research via a well-organized field campaign is needed to investigate methane emissions.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.729-736
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• 2012

The purpose of this study is to determine the possibility of using cultured wild ginseng roots as a natural health food source. To accomplish this purpose, the contents of general and antioxidative nutrients of cultured wild ginseng roots were measured. The contents of carbohydrate, crude protein, crude lipid and ash are 61.72%, 17.36%, 0.23% and 10.90%, respectively. Further, the calories of cultured wild ginseng roots were 323.97 kcal. Total dietary fiber was 82.13%. The protein contained a total of 18 different kinds of amino acids. The contents of amino acids were 16.15 g. The K was the largest mineral followed by P, Ca, and Mg, which means cultured wild ginseng roots is alkali material. The contents of saturated fatty acids and unsaturated fatty acids were 0.23 g, and 0.62 g, respectively. Crude saponine content was 25.87 mg/g. Total phenolic contents of cultured wild ginseng roots were 11.2mg/g, and total flavonoids contents were estimated as 4.2mg/g. The electron donating ability of cultured wild ginseng roots were 24.7~31.6%. The nitrite scavenging activity was pH dependent, and was highest at pH 1.2 and lowest at pH 6.0. The cultured wild ginseng roots extract showed the highest reducing power (0.06) at the concentration of $1,000{\mu}g/m{\ell}$. Based on the above results, we deemed that the cultured wild ginseng roots might have potential antioxdant activities.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.842-849
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• 2012

The purpose of this study is to determine the possibility of using Agarum cribrosum as a natural health food source. To accomplish this purpose, the contents of the general and antioxidant activities of Agarum cribrosum were measured. The contents of carbohydrate, crude protein, crude lipid and ash were 45.4%, 15.0%, 2.3% and 33.1%. The calories of Agarum cribrosum were 262.3 kcal and total dietary fiber of Agarum cribrosum was 34.0%. The protein contained a total of 18 different kinds of amino acids. The content of amino acids was 12,402.42 mg/100 g. The K was the largest mineral followed by Ca, Na and Mg, implying that Agarum cribrosum is an alkali material. The antioxidant activity of Agarum cribrosum was assessed by various radical scavenging assays using DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric ion reducing antioxidant power), reducing power, and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)). All antioxidant activity of Agarum cribrosum extract increased the concentration of the dependents. Total phenolic contents of Agarum cribrosum extract were $34.1{\pm}2.56mg/g$, and total flavonoids contents were estimated at $4.9{\pm}0.26mg/g$. General nutrients and other antioxidant bioactive materials in Agarum cribrosum were also potential materials for good health food. It is expected that a follow-up study of Agarum cribrosum through developing processed food and evaluation of their functional properties would provide useful information or sources of functional foods.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.334-340
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• 2005

This experiment was conducted to evaluate the nutrient loss and to assess the eutrophication into small stream by intensive rains in the steeped cornfield during cultivation. The crop cultivated was a soiling com (DW5969), and the experimental plots were divided into two parts that were 10 and 18% of slope degrees. The amount of T-N and T-P loss was calculated by analysis of surface run-off water quality, and was investigated the effect of eutrophication to small stream as a part of life cycle assessment (LCA) methodology application. For the surface run-off water quality, EC and T-N values were highest in first runoff event as compared to the other events and maintained the stage state with litter variations at every hour during the runoff period except for EC in the slope 18%. However, T-P concentration has been a transient stage after runoff event of July 27. Total surface run-off ratio was not significantly different with slope degrees, but amount of T-N and T-P losses at 18% of slope were high as $5.96kg\;ha^{-1}\;and\;0.65kg\;ha^{-1}$ as relative to 10% of slope degree, respectively. Furthermore, T-N losses from run-off water in the sloped cornfield 10 and 18% were approximately 9.8 and 12.5% of the N applied as fertilizer when the fertilizer applied at recommended rates after soil test, respectively. For the eutrophication impact to the small stream, it was shown that $PO_4$ equivalence and Eco-indicator value at 18% of slope degree were greater as much $6.11kg\;ha^{-1}$ and 0.81 as compared to the slope angle 10%, respectively. Therefore, it was appeared that each effect of nutrient losses, eutrophication and Eco-indicator value was enhanced according with higher slope degree.

• ALGAE
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• v.29 no.1
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• pp.47-55
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• 2014

To develop effective and safe acne vulgaris therapies with a continuing demand for new solutions, we investigated unique efficacy of an antibacterial agent from marine brown alga Eisenia bicyclis in treating acne vulgaris. The methanolic extract of E. bicyclis exhibited potential antibacterial activity against acne-related bacteria. The ethyl acetate fraction showed the strongest antibacterial activity against the bacteria among solvent fractions. Six compounds (1-6), previously isolated from the ethyl acetate fraction of E. bicyclis, were evaluated for antibacterial activity against acne-related bacteria. Among them, compound 2 (fucofuroeckol-A [FF]) exhibited the highest antibacterial activity against acne-related bacteria with a minimum inhibitory concentration (MIC) ranging from 32 to $128{\mu}g\;mL^{-1}$. Furthermore, FF clearly reversed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromycin against P. acnes were dramatically reduced from 2,048 to $1.0{\mu}g\;mL^{-1}$ in combination with MIC of FF ($64{\mu}g\;mL^{-1}$). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in combination with 32 or $64{\mu}g\;mL^{-1}$ of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acnerelated bacteria.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.325-333
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• 2011

This study was carried out to evaluate biological activities to different ethanol extracts from unripened and ripened fruit (Rubus coreanus Miq.). 25% to 75% ethanol extracts of unripened and ripened fruits were similar to extract yield respectively. Yield of ethanol extract of ripened fruit were approximately 3 times higher than that of unripened fruit. 75% ethanol extract of unripened fruit showed the highest contents of total polyphenol ($180.04{\pm}0.41$ mg/g) and total flavonoid ($50.43{\pm}0.81$ mg/g). Contents of total polyphenol and total flavonoid of unripened fruit were about 2 times higher than those of ripened fruit. $IC_{50}$ values of DPPH radical scavenging activity and linoleic acid peroxidation inhibition activity of BHA and ${\alpha}$-tocopherol showed $13.19{\pm}0.21$ and $18.16{\pm}0.23{\mu}g/m{\ell}$, $4.25{\pm}0.04{\mu}g/m{\ell}$ and $5.56{\pm}0.10{\mu}g/m{\ell}$ respectively, but 75% ethanol extract of unripened fruit showed the lowest $23.85{\pm}0.10{\mu}g/m{\ell}$ and $7.34{\pm}0.07{\mu}g/m{\ell}$ among other all extracts. $IC_{50}$ values of LDL (low density lipoprotein) oxidation inhibition activity and ${\alpha}$-glucosidase inhibitory activity of 75% ethanol extract of unripened fruit showed the lowest $1.04{\pm}0.04{\mu}g/m{\ell}$ and $7.21{\pm}0.13{\mu}g/m{\ell}$ among other all extracts respectively. Specifically, 75% ethanol extract of unripened fruit has relatively better biological activities than other ethanol extracts, it could be potentially used as bioactive source for health functional foods.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.73-79
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• 2010

The Korea Polar Research Institute (KOPRI) has assembled a culture collection of cold-adapted bacterial strains from both the Arctic and Antarctic. To identify excellent protease-producers among the proteolytic bacterial collection (874 strains), 78 strains were selected in advance according to their relative activities and were subsequently re-examined for their extracellular protease activity on $0.1{\times}$ ZoBell plates supplemented with 1% skim milk at various temperatures. This rapid and direct screening method permitted the selection of a small group of 15 cold-adapted bacterial strains, belonging to either the genus Pseudoalteromonas (13 strains) or Flavobacterium (2 strains), that showed proteolytic activities at temperatures ranging between $5-15^{\circ}C$. The cold-active proteases from these strains were classified into four categories (serine protease, aspartic protease, cysteine protease, and metalloprotease) according to the extent of enzymatic inhibition by a class-specific protease inhibitor. Since highly active and/or cold-adapted proteases have the potential for industrial or commercial enzyme development, the protease-producing bacteria selected in this work will be studied as a valuable natural source of new proteases. Our results also highlight the relevance of the Antarctic for the isolation of protease-producing bacteria active at low temperatures.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.39-44
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• 2004

Gastrodia elata has been cultivated using mycorrizal fungi including Armillaria mellea as an energy source (myco-hetrotrophy) because it is aphyllous and achlorophyllous archid. But the yields of G. elata have been recently decreased owing to the degeneration of spawn tuber arised from successive asexual reproduction. Therefore, this study was carried out to solve this degeneration by seed germination, namely sexual reproduction. The seed germination of G. elata was excellent on the fallen leaves medium of oak tree. The fruetification rate of the capsule of G. elata by artificial pollination was 94.1% and better than natural pollination. The living weight of capsules of G. elata suitable for seeds germination was above 31 mg. The middle-matured seeds and matured seeds of capules were largely germinated, while the immatured seeds was small germinated. The storage temperature of the cropped capsules suitable for a favorable seed germination was $0{\sim}5^{\circ}C$ and the storage period of it was one month.