• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1477-1482
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• 2007

Gluconacetobacter diazotrophicus strain PA15 exhibited a minimum inhibitory concentration value of 11 mM in an LGI medium amended with $ZnCl_2$. When an LGI medium was amended with Zn metal, solubilization halos were observed in a plate assay, and further solubilization was confirmed in a broth assay. The maximum solubilization was recorded after 120 h with a 0.1% Zn metal amendment. During solubilization, the culture growth and pH of the broth were indirectly correlated. Using a Fourier Transform Infrared Spectroscopy analysis, one of the agents solubilizing the Zn metal was identified as gluconic acid. When the Zn-amended broth was observed under a bright field microscope, long involution cells were observed, and further analysis with Atomic Force Microscopy revealed highly deformed, pleomorphic, aggregate-like cells.

• Polymer(Korea)
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• v.38 no.2
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• pp.150-155
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• 2014

Polycaprolactone (PCL) is a synthetic biodegradable polymer with excellent mechanical properties. $TiO_2$ (titanium dioxide) has a hydrophilic, high density and excellent biocompatibility. In this work, we produced three-dimensional porous scaffolds with PCL and $TiO_2$ nanoparticles using a salt-leaching method. Physical properties of the scaffolds were analyzed by FE-SEM, FTIR, TGA and compressive strength. Interestingly, the addition of $TiO_2$ nanoparticles decreased the water absorption and swelling ratio of the porous scaffolds. However, the compressive strength was increased by $TiO_2$. CCK-8 assay, which is generally used for the analysis of cell growth, shows that $TiO_2$ nanoparticles have no cytotoxicity. Taken together, we suggest that the PLC/$TiO_2$-scaffold can be used for biomedical applications.

• Journal of Applied Biological Chemistry
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• v.50 no.3
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• pp.148-154
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• 2007

Volatile components of the essential oils of Satsuma mandarin (C. unshiu), Dangyuza (C. grandis), Yuza (C. junos), Byungkyul (C. playtymamma), Jinkyul (C. sunki), and Hakyul (C. natsudaidai) grown in Jeju Island were isolated from the fruit peels by hydro distillation and determined by GC-MS. GC-MS analysis identified 58 compounds, with main components being d-limonene $(64.01{\sim}79.34%),\;{\beta}-myrcene\;(3.01{\sim}26.53%),\;{\gamma}-terpinene\;(0.11{\sim}12.88%),\;{\beta}-pinene\;(0.78{\sim}4.74%),\;and\;{\alpha}-pinene\;(1.01{\sim}2.55%)$. Differences in compositions and contents of the essential oils were observed among citrus varieties. Effects of citrus oils on growth inhibitions of Escherchia coli, Staphyllococcus epidermidis, and Candida albicans were investigated using disc diffusion assay and minimal inhibitory concentration (MIC) assay. The essential oils inhibited growths of the test organisms, exhibiting higher levels of activity against Gram-positive S. epidermidis (MIC values $0.04{\sim}0.17mg/mL$), whereas Gram-negative E. coli was moderately resistant (MIC values $1.66{\sim}20.30mg/mL$). MIC of citrus essential oils ranged from $0.82{\sim}23.69mg/mL$ against C. albicans. The essential oils obtained from C. sunki, C. grandis, and C. playtymamma showed the highest antimicrobial activities against S. epidermidis and C. albicans, indicating their potential as natural antimicrobial agents.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.339-345
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• 2014

This study was performed to develop a rapid immuno-assay kit, by using a specific antigen to detect Hanwoo brand meat. We selected a synthetic antigen specific to our target antibody, named BIO-TAG (Tyr-D-Ala-Phe), by utilizing a computer-based analysis and literature review. BIO-TAG tagged with adjuvant was subcutaneously injected in sheep and Hanwoo. The serum and meat juice of the immunized or non-immunized animal were then analyzed, to measure the titer of antibody by ELISA and Western blot. The amount of antibodies against the BIO-TAG increased (p<0.05) in serum by vaccination. Furthermore, meat juice from the immunized Hanwoo showed greater (p<0.05) antibody titer, compared with those from non-immunized groups. To optimze the dilution factor, we performed dot-ELISA, with various combination levels of BIO-TAG. Results from dot-ELISA showed that 2 mg/mL BIO-TAG was sufficient to distinguish the immunized meat from non-immunized groups. These results support our hypothesis that simple immunization of Hanwoo generates a sufficient amount of antibodies to be detectable in the meat juice by means of the immune-assay. Therefore, specific Hanwoo brand meat can be more precisely identified by our rapid diagnostic kit. This technology can deter possible fraud of counterfeit meat brands in the Korean domestic market with ease and rapidity; and offers a new tool that guarantees consumers high quality Hanwoo brand beef.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.8.2-8.2
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• 2007

• Korean Journal of Medicinal Crop Science
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• v.28 no.5
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• pp.371-378
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• 2020

Background: In this study, the radix of Astragalus membranaceus Bunge extract fermented by Saccharomyces cerevisiae, Weissella cibaria, and Pediococcus pentosaceus to increase the levels of isoflavonoid aglycone contents. Methods and Results: In order to change the in isoflavonoids, we fermented the radix of A. membranaceus extracts with microorganisms that have β-glucosidase activity. Besed on the β-glucosidase activity, we selected three strains, Weissella cibaria, Pediococcus pentosaceus, and Saccharomyces cerevisiae. HPLC analysis revealed that the levels of isoflavonoid aglycones were increased in all fermentation cases, and the extracts fermented by S. cerevisiae showed the highest levels of isoflavonoid aglycones. We evaluated the antioxidant activity, anti-wrinkle effects and whitening effects of the S. cerevisiae-fermented extracts using the DPPH assay, tyrosinase inhibition activity assay, and collagenase inhibition activity assay. We confirmed higher activity in S. cerevisiae-fermented extracts than in control, with the half maximal inhibitory concentration (IC₅₀) value of 565.1 ± 59.1 ㎍/㎖ in DPPH radical scavenging activity, tyrosinase inhibition rate of 78.4 ± 0.9%, and collagenase inhibition rate of 83.8 ± 1.1%. Conclusions: We selected three stains of microorganisms showing high β-glucosidase activity, W. cibaria, P. pentosaceus and S. cerevisiae. Isoflavonoid glycones in the radix of A. membranaceus were converted to isoflavonoid aglycones by fermentation. In addition, the fermented radix of A. membranaceus exhibited antioxidant activity, anti-wrinkle effect, whitening effect and radical scavenging activity.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1537-1541
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• 2006

The $^1H$ and $^{13}C$ chemical shifts of eleven flavone derivatives were completely determined by basic 1D and 2D NMR experiments. Nineteen flavone derivatives including the above eleven derivatives were examined for anti-oxidative effects using the 1,1-diphenyl-2-picryl-hydrazyl assay and Caenorhabditis elegans. In order to understand the relationships between the structures of flavone derivatives and their anti-oxidative activities, a Comparative Molecular Field Analysis was performed.

• Ocean and Polar Research
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• v.33 no.2
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• pp.127-133
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• 2011

The comet assay, also called single-cell electrophoresis (SCGE) assay, is a potential sensitive monitoring tool for DNA damage in cells. The primary objective of this study was to use comet assay to ascertain if the blood cells of flounder (Pleuronichthys olivaceus) and muscle cells of clam (Saxidomus purpurata) are suitable for genotoxicity screening. This was achieved by initially exposing blood and muscle cells under in vitro conditions to the reference genotoxin hydrogen peroxide ($H_2O_2$); strong correlation between $H_2O_2$ concentration and comet values were found. Subsequently, the identification of DNA damage in isolated cells from flounder and clam was performed under in vivo exposure to benzo(a)pyrene (BaP) and tributyltin (TBT). Flounder and clam were exposed to different concentrations (1, 10, 50, 100 ${\mu}g/L$) of BaP or TBT for 4 days. Regardless of treated chemicals, blood cells of flounder were more prone to DNA breakage compared to muscle cells of clam. In conclusion, in vivo genotoxicity of BaP and TBT can be biomonitored using the comet assay. This study suggests that flounder and clam do show potential as mediums for monitoring genotoxic damage by comet assay.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.518-521
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• 2007

생활하수처리장과 농공단지폐수처리장 방류수의 화학분석과 in vitro bio-assay를 통한 세포독성의 결과를 통해 다음과 같은 결론을 얻었다. 1) 다성분 동시분석법을 통해 다양한 성상을 가진 9곳의 방류수에서는 phenol, aliphatic compounds, polycyclic compounds, phthalate, pesticides, aromatic amines, benzens, nitro compounds이 주오염물질로 검출이 되었다. 2) 세포독성을 나타내는 TU값이 생활하수에서는 화학분석에 결과 다종고농도의 유기오염물질이 검출된 A지점과 농공폐수의 F지점에서 높게 나타났다. 즉, 화학분석결과와 in vitro bio-assay에 의한 상관관계를 유추해 볼 수 있다. 3) S9 mixture에 따른 대사활성으로 난분해성, 소수성 유기오염물질에 대한 세포독성에 악영향을 미침을 알 수 있다.

• Korean Journal of Animal Reproduction
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• v.17 no.4
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• pp.347-356
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• 1994

A simpled and sensitive microplate enzyme immunoassay(EIA) was developed for the determination of progesterone concentration in serum, based on progesterone monoclonal antibody as anti-progesterone, horseradish peroxidase(HRP) as enzyme-label and tetramethylbenzidine(TMB) as substrate. The assay has a sensitivity of 5 pg-120pg/well and intra- and inter-assay coefficients of variation for progesterone standard curve (1.0ng~10.0ng/ml) were ranged 2.5~9.9% and 1.7.8.0%, respectively, determination coefficient of the regressio equation of our standard curve(R2=0.990$\pm$0.007) were high, and this is the same level as that of commercial kit(Hormonost Bio-Lab, Germany, R2=0.98~0.99). The progesterone concentration of serum determined by both kits (Work & Bio-Lab) were significantly correlated (r=0.95, P<0.01) although a little higher value were resulted in our kit than that of commercial kit. It generally is these results indicated that the microplate-EIA can be cused for the determination of progesterone in serum, as well as, for the determination of the early pregnancy diagnosis.