• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.256-262
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• 2002

This research investigated experimentally on the population growth in the aquatic microcosm with the wastewater of plating factory. The purpose of this study was to evaluate the effect of culture conditions of the characteristic growth pattern of the examined species. Population of the system is consists of three organisms; Chlorella vulgaris as a producer, Cyclidium glaucoma as a consumer and Pseudomonas putida as a decomposer. The different growth patterns of each population are followed by surfactant type; Especially C. glaucoma was sensitive, Ch. uvlgaris was maintained population size stably even at high level of surfactant and p. putida was not significantly affected. After treatment of waste water from plating factory, it began to be affected at 1.0% solution treatment to Ch. vulgaris which the cell number was decreased prominently after 2 days, and C. glaucoma was disappeared at 2.5% solution treatment. P. putida was showed increasing pattern according to treatment concentration, at 2.5% solution and population size grew double. The result from current microcosm study indicates that this model system can be applied to environmental assessment method for various pollutants.

• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.343-349
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• 2015

A study survey about the rice cake producers completing the food hygiene education in Korea was investigated by characteristics of the rice cake business. The difference between their online and offline awareness of food hygiene education were compared. The average age of rice cake producers is 50 (40.1%), with a high school education (52.6%), 10-20 years of service (34.3%) showed the highest percentage. In relation to sales and work area, workshop personnel are engaged in two (79.5%), An area of less than $99.17m^2$ (92.0%), rent (60.2%) with most paying a monthly rental amount of less than 1 million won (54.8%). There were 228 accident cases in three years (an annual average of 2.4%), manufacturing, Processing the item number was less than 20 types of analysis (86.7%). Case of food hygiene education graduates are women, the lower the age, the higher the education level, was preferred online. Online education was chosen because of 'time, economic, convenience'(73.7%). Online graduates have recognized that health education is more conducive to business. There was no significant difference between the sales online and offline graduates. For hygienic management response was that online graduates are well above the 7.4% offline graduates. Online and offline graduates 60.7% appeared to be more satisfied than the previous training institutions.

• Korean Journal of Microbiology
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• v.20 no.3
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• pp.125-133
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• 1982

Mutational experiments were performed to imporve the cellulase productivity of Aspergillus phoenicis KU175, isolated from the southern part of Korea, as a high cellulase producer. By treatment ultra-violet light nad 4-NQO(4-Nitroquinoline-N-Oxide), mutation waas induced, and treatment ultra-violet light and 4-NQO (4-Nitroquinoline-N-Oxide), mutation was induced, and A.phoenicis KU175-115 was finally selected for its highest avicelase production. Avicelase production of the mutant was increased about 2 times compared with those of the wild strain. However, activities of other hydrolytic enzymes, such as amylase, protease and nuclease, of the mutant strain didn't show a marked difference compared with those of the nuclease, of the mutant strain didn't show a marked difference compared with the wild strain, except slight increase in ribonuclease activity and slight decrease in glucoamylase activity. Avicelases from the mutant strain selected were purified from wheat bran culture by successive salting out, followed by dialysis and column chromatography, and their charcteristics were compared with thosw of the wild strain. Avicelase was separated into three peaks in the mutant strain as well as in the case of wild strain. Avicelase II activity of the mutant strain was prominently higher than that of the wild strain, while avicelase I and III activities of those were equivalent. The optimal pH ranges and stability of avicelase II from the mutant strain were pH4-5 and pH3.5-6.0, respectively, as well as in the case of the wild strain. The optimal temperature and thermal stability of avicelase II from the mutant strain were $40{\sim}50^{\circ}C\;and\;20{\sim}55^{\circ}C$, respectively. These results were same as those of the wild strain. By the using of Eadie-Hofastee plot, $K_m\;and\;V_{max}$ of avicelase II from the mutant and the wild strain were calculated to be 2.29mg/ml and $4.84{\mu}g$ reducing sugar as glucose per min equally, from the line fitted to the data by the least square method. Activity of avicelase II from the mutant strain was slightly activated by $Mg^{++}\;but\;inhibited\;by\;Cu^{++}, \;Mn^{++}\;and\;Zn^{++}$, as well as in the case of the wild strain. Therefore, it was concluded that the mutant didn't induce the formation of another avicelase isozyme, or the changes in the properties of avicelase, but induce the changes in the productively of the same avicelase II by the action of regulatory gane.

• Microbiology and Biotechnology Letters
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• v.4 no.4
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• pp.131-137
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• 1976

Aspergillus niger S-1 was proved to be a good hesperidinase producer which have been selected for naringinase utilization. Enzyme of this strain had good characteristics and purified relative high degree with good recovery by ammonium sulfate or aceton treatment. Results obtained were summarized as follows (1) The enzyme was most active at 60$^{\circ}C$, when the reaction was performed in the pH 4.0 for 30min. Optimum pH for enzyme activity was 5.0 and activity was retained 78％ at pH value 3.5. (2) Hesperidinase activity retained 95％ of its full activity after treatment at 60$^{\circ}C$ for 30min at pH value 4.0., 70％ at 70$^{\circ}C$ and 65％ at 80$^{\circ}C$. Most stable pH of this enzyme was showed 5.0 after treatment for 24hr at 4$^{\circ}C$ (3) Only Magnesium ion activated enzyme reaction, while other metallic ions, Cu$\^$＋＋/, Mn$\^$＋＋/, Pb$\^$＋＋/, Mo$\^$＋＋/, Ag$\^$＋＋/, Hg$\^$＋＋/ inhibited. (4) Eleven fold purification with 35％ recovery was obtained in the case of 60％ aceton treatment and 10-fold purification with 5.6％ recovery was showed with 40％ aceton comparing to the crude extract Enzyme. (5) Crude enzyme precipitated with 0.4-0.6 saturated ammonium sulfate contained 13f6 of the original enzyme activity with 48-fold increase in specific activity and enzyme has been purified 25 fold with a yield 19％ by 0.6-5.8 saturation. (6) Hesperidinase formation was noticeably increased by addition of small amount of orange-peel extraction on the wheat bran medium.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.926-936
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• 2003

Overexpression of human Bcl-2 protein in recombinant Chinese hamster ovary (rCHO) cells producing humanized antibody (SH2-0.32) considerably suppressed sodium butyrate (NaBu)-induced apoptosis during batch culture by using commercially available serum-free medium, which extended the culture longevity. Due to the extended culture longevity provided by the anti-apoptotic effect of Bcl-2 overexpression, the final antibody concentration of 14C6-bcl-2 culture (Bcl-2 high producer, $23\;\mu\textrm{g}\;ml^{-1}$) was 2 times higher than that of the $SH2-0.32-{\Delta}bcl-2$ culture (cells transfected with bcl-2-deficient plasmid, $10.5\;\mu\textrm{g}\;ml^{-1}$) in the presence of NaBu. To determine the effect of NaBu/Bcl-2 overexpression on the molecular integrity of protein products, antibodies purified from 14C6-bcl-2 and $SH2-0.32-{\Delta}bcl-2$ cultures in the presence of NaBu were characterized by using various molecular assay systems. For comparison, antibody purified from the parental rCHO cell culture (SH2-0.32) in the absence of NaBu was also characterized. No significant changes in molecular weight of antibodies could be observed by SDS-PAGE. From GlycoSep-N column analysis, it was found that the core oligosaccharide structure ($GlcNAc_2Man_3GlcNAc_2$) was not affected by NaBu/Bcl-2 overexpression, while the microheterogeneity of N-linked oligosaccharide structure was slightly affected. Compared with the antibody produced in the absence of NaBu, the proportion of neutral oligosaccharides was increased from 10% (14C6-bcl-2) to 16% ($SH2-0.32-{\Delta}bcl-2$) in the presence of NaBu, which was accompanied by the reduced proportion of acidic oligosaccharides, especially of monosialylated and disialylated forms. The changes in microheterogeneous oligoformal structures of antibody in turn affected the mobility of antibody isoforms in isoelectric focusing (IEF), resulting in the occurrence of some more basic antibody isoforms produced in the presence of NaBu. However, the antigen-antibody binding properties were not changed by alteration of glycosylation pattern. The competitive enzyme-linked immunosorbent assay (ELISA) showed that the antibody produced by NaBu/Bcl-2 overexpression maintained its antigen-antibody binding properties with binding affinity of about $2.5{\times}10^9{\;}M^{-1}$. Taken together, no significant effects of NaBu/Bcl-2 overexpression on the molecular integrity of antibodies, produced by using serum-free medium, could be observed by the molecular assay systems.

• Science of Emotion and Sensibility
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• v.14 no.3
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• pp.415-424
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• 2011

Interactive media art can be said to be art in which audience participation and communication through interaction is considered to be most important Previously the role of the audience is to unilately accepted the artist's message, whereas the role of the audience observing interaction media has been changed to the point of the producer, actively participating in completing the artwork through interaction. This study analyzed the interaction and communication between the audience and interactive media artworks from the audience's point of view (in the view of reception theory) by the investigation of the case of the artworks that were on exhibition. Employing the exhibition interpretation medium with docent explanation and wall text was experienced how to improve audience's communication when they watched the artworks. The docent explained the intention of artists and their artworks in the manner of storytelling and induced the audience to focus naturally on the artworks. As the result, the role of the exhibition interpretation medium was found to be significantly high in enhancing the degree of emotional communication with the artworks, so in this study I attempted to present that the role of the docent is an important factor for enhancing the audience participation and emotional communication through interaction with the artworks.

• Environmental and Resource Economics Review
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• v.29 no.3
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• pp.313-333
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• 2020

This paper shows that when the exchange rate changes, there are conflicting effects on improving the quality and increasing market share of eco-friendly vehicles. In a vertically differentiated duopoly model consisting of high quality clean cars and low quality internal combustion engine cars, I set up a two-stage noncooperative game under perfect information that the quality levels and the prices of the cars are competitively determined. The vehicles are assumed to be produced in countries that use distinct currencies. When the exchange rate of the country that produces low quality cars rises, the producer prefers to intensify competition due to the relatively lowed cost, and the incentive for quality improvement arises from the intension of attempting to reduce the degree of differentiation of quality level. At this time, the clean car manufacturing firm tries to avoid competition due to weakened competitiveness, and increases the quality level to expand quality differentiation. However, in this case, the market share of eco-friendly vehicles shrinks. On the other hand, if the exchange rate changes in the opposite direction, the market share of eco-friendly vehicles is expected to increase, but the quality of both cars are deteriorated, causing a conflict effect.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.759-766
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• 2003

Recombinant Chinese hamster ovary (rCHO) cell lines expressing a high level of human thrombopoietin (hTPO) or its analog, TPO33r, were obtained by transfecting expression vectors into dihydrofolate reductase-deficient (dhfr) CHO cells and subsequent gene amplification in media containing stepwise increments in methotrexate (MTX) level such as 20, 80, and 320 nM. The parental clones with a hTPO expression level $>0.40\;{\mu}g/ml$ (27 out of 1,200 clones) and the parental clones with a TPO33r expression level $>0.20\;{\mu}g/ml$ (36 out of 400 clones) were subjected to 20 nM MTX. The clones that displayed an increased expression level at 20 nM MTX were subjected to stepwise increasing levels of MTX such as 80 and 320 nM. When subjected to 320 nM MTX, most clones did not display an increased expression level, since the detrimental effect of gene amplification on growth reduction outweighed its beneficial effect of specific TPO productivity ($q_{TPO}$) enhancement at 320 nM MTX. Accordingly, the highest producer subclones ($1-434-80^{*}$ for hTPO and $2-3-80^{*}$ for TPO33r), whose $q_{TPO}$ was 2- to 3-fold higher than that of their parental clones selected at 80 nM MTX, were isolated by limiting dilution method and were established as rCHO cel1 lines. The $q_{TPO}$ of $1-434-80^{*}\;and\;2-3-80^{*}\;was\;5.89{\pm}074\;and\;1.02{\pm}0.23\;{\mu}g/10^6$ cells/day, respectively. Southern and Northern blot analyses showed that the enhanced $q_{TPO}$ of established rCHO cell lines resulted mainly from the increased TPO gene copy number and subsequent increased TPO mRNA level. The hTPO and TPO33r produced from the established rCHO cell lines were biologically active in vivo, as demonstrated by their ability to elevate platelet counts in treated mice.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.1-9
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• 2013

Long term hydrogen production was investigated in an anaerobic sequencing batch reactor (ASBR) using mixed microflora. Glucose (about 8,250 mg/L) was used as a substrate for the ASBR operation under the condition of pH 5.5 and $37^{\circ}C$ with mixing at 150 rpm. The experiment was carried out over a period of 160 days. Hydrogen yield was 0.8mol $H_2/mol$ glucose with F/M ratio 2 at initial operation period. The hydrogen yield reached to maximum 2.6 mol $H_2/mol$ glucose at 80th day operation. However decreased hydrogen yield was observed after 80 days operation and eventually no hydrogen yield. Although well-known hydrogen producer Clostridium sp. was detected in the reactor by PCR-DGGE analysis, changed reactor operation was the major reason of the decreased hydrogen production, such as low F/M ratio of 0.5 and high propionic acid concentration 2,130 mg/L. Consequently the long period operation resulted in MLSS accumulation and then low F/M ration stimulating propionic acid formation which consumes hydrogen produced in the reactor.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.231-238
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• 2018

This study was carried out to develope new zoysiagrass cultivars 'JangsungChorok' (Application No. :2013-3) and 'JangsungSaetbyeol' (Application No. :2013-4). One hundred and one genetic resources were collected at Jangsung Gun area from 2010 to 2011. Among the collected lines, CY6097 (JangsungChorok) and CY6069 (JangsungSaetbyeol) showed superior performance in spring green up and growth rate. 'JangsungChorok' showed genetically light green leaf color, with medium leaf width (4.4 mm), height from ground to first leaf blade of 3.2 cm and average plant height of 18 cm. Fast recovery rate and early spring green up rate will make this cultivar (JangsungChorok) for efficient sod producer. 'JangsungSaetbyeol' showed genetically dark green leaf color, with fine to medium leaf width of 3.5 mm, height from ground to first leaf blade of 4.3 cm and average plant height of 22.6 cm. Fast recovery rate and early spring green up rate with relatively narrow leaf will make this cultivar (JangsungSaetbyeol) for high sod quality.