• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.21-24
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• 2004

To determine lethal temperature of alfalfa (Medicago sativa L. cv Vernal) at heat-stressed conditions, seedlings grown in a small pots for 4 weeks were subjected to different temperature regimes of heat treatment. No apparent demage was observed when the plants were treated at 45, 50 or $60^{\circ}C$ for 1 h. Heat treatments at 60 and $65^{\circ}C$ for 1 h, several plants were withered and showed damage symptom on their leaves. When the plants were exposed to $70^{\circ}C$ for 1 h, most of leaves were severely withered, but it was not lethal conditions for the whole plants. By contrast, most of plants were died within one day after heat treatment at $80^{\circ}C$ for 1h. Furthermore, plants exposed to $80^{\circ}C$ for 50 min were also died within 7 days. It was found that new shoots were regenerated from the plants that had been treated at $80^{\circ}C$ within 45 min. These results indicate that heat treatment at $80^{\circ}C$ for 50 min is an optimum condition to distinguish the lethality of alfalfa plants. Simple viability assay system established in this study will be useful fer selection and characterization of heat-tolerant transgenic alfalfa plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.25-28
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• 2004

To determine lethal temperature of orchardgrass (Dactylis glomerata L. cv. Janbeol 102) developed in Korea at heat-stressed conditions, seedlings grown in a amall pots for 4 weeks were treated at $45^{\circ}C$, $50^{\circ}C$ or $55^{\circ}C$ for 1 h. Heat treatments at $60^{\circ}C$ and $65^{\circ}C$ for 1 h, several plants were withered and showed damage symptom on their leaves. When the plants were exposed to $70^{\circ}C$ for 1 h, most of leaves were severely withered, but it was not lethal conditions for the whole plants. By contrast, most of plants were died within one day after heat treatment at $80^{\circ}C$ for 1h. Furthermore, plants exposed to $80^{\circ}C$ for 55 min were also died within 7 days. It was found that new shoots were regenerated from the plants that had been treated at $80^{\circ}C$ within 50 min. These results indicate that heat treatment at $80^{\circ}C$ for 55 min is an optimum condition to distinguish the lethality of orchardgrass plants. Simple viability assay system established in this study will be useful for selection and characterization of heat-tolerant transgenic orchardgrass plants.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.493-497
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• 2012

The objective of this study was carried out in order to evaluate the antioxidative activities of n-hexane fractions from medicinal herbs. Certain parts from 6 species of edible and medicinal herbs were extracted with methanol. Radical scavenging activity of the n-hexane fractions against DPPH and ABTS radicals were observed to be high in Psoralea corylifolia, and Scutellsria barbata; it also significantly increased (p<0.05). For a comparison of the effect of various concentration of fractions, as the concentration of treatment increased, the antioxidative effects on radical scavenging activity also oncreased; yet it was not significant. The antioxidative effect of medicinal plants was dependent on the concentration but was not significant. Therefore, these results indicate that edible wild plants, such as Psoralea corylifolia, and Scutellsria barbata may be useful as potential antioxidant sources for improving the human antioxidant defense system against disease.

• Journal of Life Science
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• v.24 no.9
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• pp.995-1000
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• 2014

The studies of marine viruses in terms of viral isolation and detection have been limited due to the high mutation rate and genetic diversity of marine viruses. Of the modern methods currently used to detect marine viruses, serological methods based on enzyme-linked immunosorbent assay (ELISA) are the most common. They depend largely on the quality of the antibodies and on highly purified suitable antigens. Recently, a new experimental system for using viral capsid protein as an antigen has been developed using the yeast surface display (YSD) technique. In the present study, the capsid protein gene of the red-spotted grouper nervous necrosis virus (RGNNV) was expressed and purified via YSD and HA-tagging systems, respectively. Two regions of the RGNNV capsid protein gene, RGNNV1 and RGNNV2, were individually synthesized and subcloned into a yeast expression vector, pCTCON. The expressions of each RGNNV capsid protein in the Saccharomyces cerevisiae strain EBY100 were indirectly detected by flow cytometry with fluorescently labeled antibodies, while recognizing the C-terminal c-myc tags encoded by the display vector. The expressed RGNNV capsid proteins were isolated from the yeast surface through the cleavage of the disulfide bond between the Aga1 and Aga2 proteins after ${\beta}$-mercaptoethanol treatment, and they were directly detected by Western blot using anti-HA antibody. These results indicated that YSD and HA-tagging systems could be applicable to the expressions and purification of recombinant RGNNV capsid proteins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.143-148
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• 1992

The antimutagenic effects of green-yellow vegetables toward aflatoxin B$_1$(AFB$_1$) and 4-nitroquinoline-1-ox-ide (4-NQO) using the Ames assay system with Salmonella typhimurium TA98 and TA100 were studied. Forty six to fifty percent of the methanol extracts of the vegetable samples inhibited the mutagenicity induced by AFB$_1$in TA98 and TA100. Perilla leaf, lettuce, broccoli, crown daisy, water dropwort, small water dropwort, red pepper, red pepper leaves, amaranth, spinach and radish root were significantly reduced the mutagenicity of AFB$_1$(p< 0.01). Whereas 25 out of 27 samples (93%) exhibited antimutagenicity toward a direct mutagen of 4-NQO (p< 0.01. 0.05). The samples which showed the strong antimutagenicity (>60%) were cabbage, kale, lettuce, broccoli, mustard leaf, green red pepper, green sweet pepper, spinach, amaranth, soybean sprout and immature pumpkin. The juices from the several samples also showed antimu-tagenic activity toward AFB$_1$. Cabbage, perilla leaf, small water dropwort and spinach reduced TAT100 revertants dose dependently in the range of 50-500$m\ell$/plate, however, cucumber and carrot showed little effect.

• KSBB Journal
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• v.22 no.6
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• pp.371-377
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• 2007

Polyhydroxyalkanoates (PHAs) are a family of microbial polyesters that can be produced by fermentation from renewable resources. PHAs can be used as completely biodegradable plastics or elastomers. In this paper, novel applications of PHAs in biosensor are described. A general platform technology was developed by using the substrate binding domain (SBD) of PHA depolymerase as a fusion partner to immobilize proteins of interest on PHA surface. It could be shown that the proteins fused to the SBD of PHA depolymerase could be specifically immobilized onto PHA film, PHA microbead, and microcontact printed PHA surface. We review the results obtained for monitoring the specific interaction between the SBO and PHA by using enhanced green fluorescent protein, red fluorescent protein, single chain antibody against hepatitis B virus preS2 surface protein and severe acute respiratory syndrome coronavirus surface antigen as model proteins. Thus, this system can be efficiently used for studying protein-protein and possibly protein-biomolecule interactions for various biotechnological applications.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.336-342
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• 2015

Previously, Euptelea pleiosperma was identified as one of the useful sources containing anti-oxidative and anti-inflammatory activities for the first time in our research group. In this study, anti-obesity effect of E. pleiosperma ethanol extract (EPEE) was evaluated by using a pancreatic lipase enzyme inhibition assay and a cell culture model system. EPEE suppressed effectively pancreatic lipase enzyme activity dose dependently. Furthermore, EPEE significantly suppressed adipocyte differentiation, lipid accumulation, triglyceride contents, and triggered lipolysis activity on 3T3-L1 preadipocytes in a dose-dependent manner without cytotoxicity. Anti-adipogenic effect of EPEE was modulated by cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins ${\alpha}(C/EBP{\alpha})$, $C/EBP{\beta}$ and peroxisome proliferator-activated receptor ${\gamma}(PPAR{\gamma})$ gene and protein expressions. Taken together, these results provide the important new insight that E. pleiosperma possesses anti-obesity activities such as pancreatic lipase inhibition, anti-adipogenic, and lipolysis effects. It might be utilized as promising sources in the fields of nutraceuticals. The identification of active compounds that confer anti-obesity activity of EPEE might be needed.

• Journal of Dairy Science and Biotechnology
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• v.21 no.2
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• pp.97-104
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• 2003

It is extremely important to destroy the antigenicity of milk proteins for dietetic treatment of infants with milk allergy. Enzymatic digestion of milk protein is not only effective for destroying antigenicity, but it also is less liable to alter the nutritive value. Bovine casein was hydrolyzed with eight different commercial proteases derived from bacterias or fungi, either individually or in combination to eliminate protein allergenicity. The average molecular weight of casein hyrdolysates determined by size exclusion chromatography is about 550${\sim}$2,300 dalton range. Antigenicity of the casein hyrdolysates was not detected by heterologous passive cutaneous anaphylaxis in guinea pig-rabbit antiserum system. The inhibition test on the enzyme-linked immunosorbent assay(ELISA) showed that the antigenicity of casein hydrolysates is lowed up to 1/8,000 than that of intact bovine casein. As the enzyme reaction was carried out by the combination of bacterial and fungal protease, casein hydrolysates showed much lower bitterness and antigenicity. It suggests that these hydrolysates will be applied to many kinds of foods including the development of hypo-allergenic infant formula.

• Analytical Science and Technology
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• v.18 no.6
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• pp.500-510
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• 2005

This study was conducted to investigate the chemical composition of essential oil, absolute and oleoresin isolated from Elsholtzia splendens and their biological activities. Yields of essential oil, absolute and oleoresin extracted from Elsholtzia splendens were 0.28%, 12.45% and 9.95%, respectively. The major component was 2-cyclohexen-1-one in essential oil, methyl linolenate in absolute and 9,12,15-octadecatrienoic acid in oleoresin. Essential oil and oleoresin showed the inhibitory activities in enzyme-dependent, enzyme-independent and autooxidative lipid peroxidation system. $EC_{50}$ values in nuetral red uptake (NRU) assays for the exposure times of 24 h were $46.4{\mu}g/ml$, $681.7{\mu}g/ml$ and $17.6{\mu}g/ml$ in essential oil, absolute and oleoresin, and oleoresins showed the cytotoxic effect at the only high dose. Any mutagenic and antibiotic activity did not show in absolute and oleoresin, but, there were mutagenic and antibiotic activities only when treated with essential oil $500{\mu}g/ml$ above in Ames test. Essential oil and oleoresin might be somewhat effective in prolongating the ciliostasis of rat trachea.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.235-242
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• 2004

A system for the production of transgenic plants has been developed for Italian ryegrass(Lolium mult리orum Lam.) via Agrobacterium-mediated transformation of embryogenic callus. Mature seed-derived calli were infected and co-cultured with Agrobacterium EHA101 carrying standard binary vector pIG121Hm encoding the hygromycin phosphotransferase(HPT), neomycin phosphotransferase II (NPTII) and intron-oontaining $\beta$g1ucuronidase( intron-GUS) genes in the T-DNA region. The effects of several factors on transformation and the expression of the GUS gene were investigated. Inclusion of 200${\mu}M$ acetosyringone(AS) in inoculation and co-cultivation media lead to a significant increase in stable transformation efficiency. Increasing Agrobacterium cell density up to 1.0 in $OD_{600}$ during infection increased transfonnation efficiency of embryogenic calli. The highest transfonnation efficiency was obtained when embryogenic calli were incoulated with Agrobacterium in the presence of 0.1% Tween20 and 200${\mu}M$ AS. Hygromycin resistant calli were developed into complete plants via somatic embryogenesis. GUS histochemical assay and PCR analysis of transgenic plants demonstrated that transgenes were integrated into the genome of Italian ryegrass.