• Food Science of Animal Resources
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• v.37 no.2
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• pp.305-312
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• 2017

This study was conducted to establish the shelf-life of a milk beverage product supplemented with coffee extracts. Qualitative changes including peroxide value (PV), microorganism content, caffeine content, and sensory evaluation were measured periodically in beverages kept at 10, 20, and $30^{\circ}C$ for 8 wk. Lipid oxidation of the product was measured by peroxide value analysis, and apparent changes were observed during a 4 wk storage period. Caffeine analysis revealed that the changes in caffeine content were negligible during the storage period. Total aerobic bacteria, Escherichia coli, yeast, and mold were not detected in the products during an 8 wk storage period. Sensory evaluation revealed that after 4 wk of storage overall acceptance was less than 3 points on a 5-point scale. In this study, PV was used as an indicator of the shelf-life of the milk beverage product. PV analysis revealed that a value of 20 meq/kg was the end of the shelf-life using the Arrhenius equation and the accelerated shelf-life test (ASLT). Assuming that the beverages are kept at $4^{\circ}C$ during distribution, calculation of when the PV reached the quality limit point (20 meq/kg) was done with the equation ln(PV) = 0.3644X - 2.21834 and, using that equation, $PV=e^{0.3644X-2.21834}$ was calculated. Therefore, 14.3086 wk was determined to be the shelf-life of the milk beverage supplemented with coffee when stored at $4^{\circ}C$.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.259-268
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• 2003

Lactadherin (formerly known as BA46), a major glycoprotein of the human milk fat globule membrane, is abundant in human breast milk and breast carcinoma cells and is known to prevent symptomatic rotavirus infections. In this study, we tried to transfer the human lactadherin gene to the Chinese Hamster Ovary (CHO) cells using retrovirus vector system and tested inducible expression of the gene under the tetracycline-controllable promoter. At first, tetracycline-mediated inducibility was tested using E.coli LacZ marker gene. NIH3T3 cells co-infected with RevTet-On and RevTRE-LacZ retrovirus vectors showed that the cells responded to doxycycline (a derivative of tetracycline) in a dose-dependent manner, and prominent induction of the lacZ gene expression was observed from 1 $\mu\textrm{g}$/ml of doxycycline concentration. Based on the results of the pilot experiment, inductional expression of the human lactadherin gene was conducted using RevTet-On and RevTRE-Ltd retrovirus vectors. Analysis with the RT-PCR demonstrated successful inductional expression of the lactadherin gene in the Chinese Hamster Ovary (CHO) cells. Considering that constitutive overexpression of the exogenous genes in the target cells causes serious physiological imbalance, the results obtained in this study will be very useful especially in the studies of gene therapy and transgenic animal production.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.327-333
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• 2005

Dihydroxy-acid dehydratase (DHAD, 2,3-dihydroxy-acid hydrolyase, EC 4.2.1.9) is one of the key enzymes involved in the biosynthetic pathway of the branched chain amino acid isoleucine and valine. Although the enzyme have been purified and characterized in various mesophiles including bacteria and eukarya, the biochemical properties of DHAD has bee not yet reported from hyperthermophilic archaea. In this study, we cloned, expressed, and purified a DHAD homologue from the thermoacidophilic archaeon Sulfolobus solfataricus P2, which grows optimally at $80\;^{\circ}C$ and pH 3, in E. coli. Characterization of the recombinant S. solfataricus DHAD (rSso_DHAD) revealed that it is the dimeric protein with a subunit molecular weight of 64,000 Da in native structure. rDHAD showed the highest activity toward 2,3-dihydroxyisovaleric acid among 17 aldonic acid substrates Interestingly, this enzyme also displayed 50 % activities toward some pentonic acids and hexonic acids when compared with the activity of this enzyme to the natural substrate. Moreover, rSso_DHAD indicated relatively higher activity toward D-gluconate than any other hexonic acids tested in substrates. $K_m$ and $V_{max}$ values of rSso_DHAD were calculated as $0.54\;{\pm}\;0.04\;mM$ toward 2,3dihydroxyisovalerate and $2.42\;{\pm}\;0.19\;mM$ toward D-gluconate, and as $21.6\;{\pm}\;0.4\;U/mg$ toward 2,3-dihydroxyisovalerate and $13.8\;{\pm}\;0.4\;U/mg$ toward D-gluconate, respectively. In the study for biochemical properties, the enzyme shows maximal activity between $70^{\circ}C$ and $80^{\circ}C$, and the pH range of pH 7.5 to 8.5. The half life time at $80^{\circ}C$ was 30 min. A divalent metal ion, $Mn^{2+}$, was only powerful activators, whereas other metal ions made the enzyme activity reduced. $Hg^{2+}$, organic mercury, and EDTA also strongly inhibited enzyme activities. Particularly, the rSso_DHAD activity was very stable under aerobic condition although the counterparts reported from mesophiles had been deactivated by oxygen.

• Korean Journal of Food Science and Technology
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• v.12 no.1
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• pp.45-52
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• 1980

The nylon (poly 6, 10) microcapsules containing ${\beta}-galactosidase$ were obtained by the interfacial polymerization of 1, 6-diaminohexane and sebacoyl chloride with ${\beta}-galactosidase$ from Escherichia coli. They were generally spherical and had a mean diameter of $80{\mu}$ with 45 % of the activity recovery. In particular, there was no transport hamper of lactose through the membrane of microcapsules. The characteristics of the microencapsulated enzyme were similar to those of soluble enzyme optimal pHs, $7.0{\sim}7.2$ for the soluble and $7.3{\sim}7.5$ for the microencapsulated ; optimal temperatures, $50^{\circ}C$ for both ; apparent $K_m,\;3.33{\times}10^{-4}(on ONPG),$ $2.86{\times}10^{-3}$ M(on lactose) for the soluble and $5.28{\times}10^{-4}$ (on ONPG), $4.25{\times}10^{-3}$ M (on lactose) for the microencapsulated ; activation energies, 8.94 for the soluble and 9.78 Kcal/mole for the microencapsulated enzyme. Using this microencapsulated ${\beta}-galactosidase$, hydrolyses of lactose and milk lactose were carried out and 80 % of 5 % lactose solution and 70 % of lactose in skim milk were hydrolyzed in 40 hr at $27^{\circ}C$. The reusability and operational stability showed that the remaining activity was 50 % of the original activity after 5 runs and 120 hr of total operating time at $27^{\circ}C$.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.23-29
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• 1997

To develop novel cephem antibiotics, We have synthesized a new compound, named YH-487, by attaching the thiol and aminothiazole residue to $C_3$ and $C_7$ position of 7-ACA, respectively. Several characteristics such as structure, antibiotic spectrum, action mechanism, stability against ${\beta}-lactamase$ and synergistic effect were investigated. Anti-bactericidal activity of YH-487 against gram-positive and gram-negative bacteria were superior to that of the other cephem antibiotics. We have examined the action mechanisms of YH-487 using penicillin binding protein (PBP) assay, and found that the bactericidal activity was obtained by inhibiting PBP-1A, PBP-1B and PBP-3. YH-487 showed synergistic effect with gentamicin, tobramycin, and amikacin against Pseudomonas aeruginosa. In addition, YH-487 was effective against Enterobacter cloacae in combination with amikacin. Based on the above observations, YH-487 was classified as a novel third-generation ${\beta}-lactam$ antibiotics.

• Journal of the Korean GEO-environmental Society
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• v.9 no.6
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• pp.13-19
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• 2008

The objectives of this paper are to investigate states of these open dumping landfills for managing, utilizing and stabilization of a municipal solid waste landfill site in environmentally secure conditions. The result of the physical analysis of the landfill showed that it is composed of between 29.72-63.84% organic matter, 32.88% vinyl plastic. The environmental assessment of the landfill site confirmed that the landfill is at a maturation phase due to 0.18 of $BOD_5$/CODcr of leachate. VS and FS of TS Was respectively 30.37%, 32.34% and C/N ratio was 21.8. Surface water around landfill was BOD 10.7 mg/g, SS 37.8 mg/g, E-Coli 31,157(MPN/$100m{\ell}$) and Ground water was $COD_{Mn}$ 1.13-1.38 mg/g, $NO_3-N$ 1.025-4.075 mg/g. Leachat indicated T-P 0.002-0.028 mg/g, $NH_3-N$ 4.0-21.0 mg/g. The soil contamination of around landfill didn't appear as below of the regulation of Soil Environment Conservation Act. The Landfill Gas was $CH_4$ 13.25%, $CO_2$ 6.17%, H2S and CO was not detected. Also Surface Water was not detected $CO_2$, $CH_4$, $H_2S$, CO.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.649-654
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• 2006

It was investigated the effects of pre-treatment method on the microbes on the surface of radish (Raphanus sativus L.) leaves. Independent variables put in water washing ($X_1$), microwave treatment ($X_2$) and steam treatment ($X_3$) using central composite design and response surface analysis. It was not detected in the pathogenic microbes, Samonella spp., Camphylobacter spp., Vibrio spp., Shigella spp., Staphyloccocus spp., on the surface of collected radish leaves without pre-treatment. But general microbes showed $3.90{\times}10^5{\sim}1.20{\times}10^7CFU/g$ of total microbes, $1.10{\times}10^2{\sim}2.00{\times}10^5CFU/g$ of E. coli, $2.40{\times}10^3{\sim}3.55{\times}10^6CFU/g$ of yeast/mold on the surface of various radish leaves and lactic acid bacteria was detected or not according to collected samples. The best method of pre-treatment was steam treatment on the microbe reduction effect of samples surface. Also, the multiplex regression coefficients analysis was calculated three independent variables ($X_1,\;X_2,\;X_3$) and dependent variables (total microbes, lactic acid bacteria and yeast/molds). It showed high correlation $R^2$, 0.89, 0.87, 0.85, respectively. For effective reduction of surface microbes, the best method was water washing with microwave or steam treatment at the same time.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.47-54
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• 2014

Objectives: The purpose of this study is to evaluate the characteristics of leachate discharged from livestock burial sites in Gangwondo resulting from foot-and-mouth disease by monitoring the water quality at the survey tube-wells installed near livestock burial sites in order to investigate the effect of the leachate on the quality of nearby underground water and suggest a water pollution level in accordance with water quality evaluation criteria. Methods: To minimize the secondary environmental pollution damage caused by leachate at burial sites of livestock killed by foot-and-mouth disease, this study analyzed the leachate directly discharged from burial sites and installed survey tube-wells within 300 meters of livestock burial sites and investigated water quality as a means to ascertain the environmental effect of the leachate from the burial sites. In accordance with environmental management guidelines on livestock burial sites, this research investigated the water quality in the survey tube-wells in fifty five burial sites in Gangwondo. The elements investigated were $NH_3$-N, $Cl^-$, $NO_3$-N, conductivity, and E. coli. Water quality was monitored from 2011 to 2013. Results: The water quality from the drain pipe at the location of leachate from livestock burial sites showed BOD 37,209 mg/L, COD 8,829 mg/L, $NH_3$-N 3,633 mg/L, and $Cl^-$ 580 mg/L. According to the monitoring results of water quality ($Cl^-$, $NH_3$-N, conductivity) at the survey tube-wells, there was suspicion that 13 out of 55 burial sites discharged leachate, five sites discharged highly concentrated leachate (13%): one in Gangneung, one in Wonju, and three in Cheorwon. Conclusion: It was judged that out of thirteen observation wells which showed a possibility of discharged leachate, three survey tube-wells have established the discharge effect of leachate at burial sites up to recently. Therefore, it is judged that it is necessary to continue monitoring them and devise additional measures.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.457-463
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• 2013

The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of dressing. The hazard analysis examined the main materials, industrial water, microbial evaluation, and airborne microorganisms of each working area, as well as the pathogenic microbial contamination risk. The survey was conducted at SJ Company in Jincheon (Chungchengbuk-do), Korea for 30 days from April 1, 2012 to April 30, 2012. The results showed that raw material microorganisms had a total plate count in industrial water below $3.00{\times}10$ CFU/mL in working room I, working room II, the packing room, washing water, and the inspection room for five times in each place. During dressing production (including heat treatment and mixing), general bacteria were detected at an average of $3{\times}10$ CFU/mL, but yeast, mold, and pathogenic bacteria were not detected. Airborne microbiological evaluation (for total plate count, yeast, and mold) found levels below the legal limit at each working area. While workers were positive for microbes in total plate counts, coliform and Staphylococcus aureus were not detected. In conclusion, standards for hygienic management should be established to prevent and decrease hazards, such as general bacteria and pathogenic microorganisms (for example, E. coli, B. cereus, Listeria spp, Salmonella spp, Staph. aureus, Clostridium perfringens, yeast, and mold), and to found critical limits for microorganisms with an HACCP system.

• Journal of Life Science
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• v.26 no.11
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• pp.1225-1231
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• 2016

In this study, our investigated the antioxidant activities and compared other bioassay including anti-microbial, antifungal activities and total polyphenol contents of functional healthy drinks from some medicinal herbs and coffee mixture. The kind of medicinal herbs, chaga mushroom (Inonatus obliqurs), moringa (Moringa Oleifera), gravila (Anona muricata), mulberry (Morus alba), Dioscoreaceae (Dioscorea quinquelaba), Berberidaceae (Epimedii Herba), Asteraceae (Artemisia capillaries) and siberian ginseng (Acanthopanax senticous,). The functional healthy drinks, named C1, C2, C3, C4, C5, C6 and C7 were summered in Table 1. The in vitro antimicrobial activity was examined against Gram positive bacteria, Gram negative bacteria and a fungus. The functional healthy drinks were broad spectrum of anti-microbial activity without antifungal activity against Candida albicans KCTC7965. In particularly, the C7 showed strong activity against Methicillin Resistant Staphylococcus aureus CCARM3089, CCARM 3115 and CCARM3561. And, the C7 showed 88% of free radical scavenging effect on 0.5 mg/ml using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Functional healthy drink C7 was mulberry extracts from Morus alba, chaga mushroom from Inonatus obliqurs and moringa from Moringa olifera in additionally coffee extracts. Its results confirm that the potential use of mulberry extracts as a good source of antibacterial compounds or as a health promoting food and health drinks.