• Journal of Life Science
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• v.31 no.3
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• pp.356-365
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• 2021

Recently, we sequenced the entire genome of a freshwater agar-degrading bacterium Cellvibrio sp. KY-GH-1 (KCTC13629BP) to explore genetic information encoding agarases that hydrolyze agarose into monomers 3,6-anhydro-L-galactose (L-AHG) and D-galactose. The KY-GH-1 strain appeared to possess nine β-agarase genes and two α-neoagarobiose hydrolase (α-NABH) genes in a 77-kb agarase gene cluster. Based on these genetic information, the KY-GH-1 strain-caused agarose degradation into L-AHG and D-galactose was predicted to be initiated by both endolytic GH16 and GH86 β-agarases to generate NAOS (NA4/NA6/NA8), and further processed by exolytic GH50 β-agarases to generate NA2, and then terminated by GH117 α-NABHs which degrade NA2 into L-AHG and D-galactose. More recently, by employing E. coli expression system with pET-30a vector we obtained three recombinant His-tagged GH50 family β-agarases (GH50A, GH50B, and GH50C) derived from Cellvibrio sp. KY-GH-1 to compare their enzymatic properties. GH50A β-agarase turned out to have the highest exolytic β-agarase activity among the three GH50 isozymes, catalyzing efficient NA2 production from the substrate (agarose, NAOS or AOS). Additionally, we determined that GH117A α-NABH, but not GH117B α-NABH, could potently degrade NA2 into L-AHG and D-galactose. Sequentially, we examined the enzymatic characteristics of GH50A β-agarase and GH117A α-NABH, and assessed their efficiency for NA2 production from agarose and for production of L-AHG and D-galactose from NA2, respectively. In this review, we describe the benefits of recombinant GH50A β-agarase and GH117A α-NABH originated from Cellvibrio sp. KY-GH-1, which may be useful for the enzymatic hydrolysis of agarose for mass production of L-AHG and D-galactose.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.1
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• pp.20-35
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• 2023

Chemical preservatives have a good effect on antibacterial activity, but many side effects on the human body have been reported. Recently, the development of natural preservatives that are harmless to the human body and have preservative functions and self-efficacy is active. In addition, in order to increase the absorption rate of natural products by the human body, the method of fermentation using strains is also increasing. Therefore, this study selected varieties that are harmless to the human body and have good antibacterial activity. 1. The yield of origin, thickness and solvent was investigated. Scutellaria baicalensis Georgi was made in China and received a yield of 21.88% from 50% ethyl alcohol extract. Salvia miltiorrhiza Bunge was made in Korea and received a yield of 25.62% from 50% ethyl alcohol extract. Dryopteris crassirhizoma Nakai was made in China and received a yield of 6.50% from 70% ethyl alcohol extract. 2. The solid fermentation with the S. baicalensis and S. miltiorrhiza with B. Subtilis yield gained 24.40%, 39.30%, and D. crassirhizoma obtained 11.10% yield when fermented with L. casei. 3. After the liquid fermentation, a clear zone of 9mm was identified for the S. aureus strain in the S. baicalensis, and the antibacterial activity was not confirmed in S. miltiorrhiza and D. crassirhizoma. 4. When the S. baicalensis was fermented with L. Casei, it showed high antibacterial activity in C. albicans and S. aureus. S. miltiorrhiza showed antibacterial activity in S. aureus when it was solid with S. cerevisiae. When the spectators were solid with L. casei and S. cerevisiae, antibacterial activity was high in E. coli and S. aureus. Overall, the antibacterial activity after fermentation was much higher than when fermented. 5. The change in active ingredients was baicalin 101.57, baicalein 28.26, and wogonin 5.33mg/g in the S. baicalensis that did not ferment solid. When solid fermentation with S. cerevisiae, the content of baicalinin with baicalin 94.31, baicalein 30.41, and wogonin 3.57mg/g was found to have increased. S. miltiorrhiza that was not fermented, salvianolic acid A was 1.82mg/g, and when fermented with S. cerevisiae, it increased to 5.70mg/g. The active ingredients of the spectators were flavaspidic acid AP, flavaspidic acid PB, flavaspidic acid AB, and flavaspidic acid BB.

• Clean Technology
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• v.29 no.1
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• pp.10-21
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• 2023

Hydrogels that are made of natural polymer-based double networks have excellent biocompatibility, low cytotoxicity, and high water content, assuring that the material has the properties required for a variety of biomedical applications. However, hydrogels also have limitations due to their relatively weak mechanical properties. In this study, hydrogels based on an alginate di-aldehyde (ADA) and gelatin (Gel) double network that is reinforced with additional hydrogen bonds formed between the hydroxyl (-OH) groups of the hyperbranched polymer (HPG) and the functional groups present inside of the hydrogels were successfully synthesized. The enhanced mechanical properties of these synthesized hydrogels were evaluated by varying the amount of HPG added during the hydrogel synthesis from 0 to 25%. In addition, magnetite nanoparticles (Fe₃O₄ NPs) were synthesized within the hydrogels and the structures and the magnetic properties of the hydrogels were also characterized. The hydrogels that contained 15% HPG and Fe₃O₄ NPs exhibited superparamagnetic behaviors with a saturation magnetization value of 3.8 emu g^-1. These particular hydrogels also had strengthened mechanical properties with a maximum compressive stress of 1.1 MPa at a strain of 67.4%. Magnetic hydrogels made with natural polymer-based double networks provide improved mechanical properties and have a significant potential for drug delivery and biomaterial application.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.49-57
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• 2000

This study was conducted to investigate the developmental potential of cloned embryos derived from bovine fetal fibroblast cells, and the effect of quiescent treatment, passage number and origin of donor cells on in vitro development of cloned embryos. Fetal skin and liver-derived fibroblast cells were transferred to enucleated oocytes after serum starvation or nontreatment (cycling). After electrofusion. reconstituted embryos were activated with $Ca^{＋＋}$-ionophore and cycloheximide, and cocultured for 7~9 days with BRL cells. Some blastocysts were transferred to recipient cows 7~8 days post estrus. The development rate to the blastocyst stage of serum starved cell-derived embryos was higher (25.3%) than that of actively dividing cells-derived embryos (15.9%), The rates of blastocyst formation were 23.1~25.0% after transfer of cell passaged 4 to 6 times, and 23.8 and 25.2% after transfer of fetal skin and liver cells, respectively. After embryo transfer, 34.4% and 15.6% of recipient cows were pregnant on Day 60 and 120, respectively, and one male calf was produced from skin-derived vitrified blastocyst. The result of this study showed that the development of cloned embryos. was enhanced by quiescent treatment, but did not different among the cells passaged 4 to 6 times, and between skin and liver cells. This result also confirms that offspring can be obtained from the vitrified clone embryo derived from fetal skin cell.

• Sim-seong Yeon-gu
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• v.25 no.2
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• pp.224-264
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• 2010

A brief story of the tale follows : Mokdoryung was a son of an arbor tree and a fairly. When the boy was 7-8 years old, mother-fairy returned to the sky. By using father-tree, Mokdoryung survived from the flood where he saved ants, mosquitos, and a boy with the same age. They arrived on top of the highest mountain, met an old woman with two daughters, worked as servants. With help of insects, Mokdoryung passed the trials, married to a wise daughter and 2 couples became the ancestor of the mankind. Interpretation of the tale starts with amplification of tree which symbolizes Self and Libido. As the son of the tree-spirit and a fairly from the sky, Mokdoryung is a kind of 'divine child' which represents a psychic possibility to understand archetypal nature of unconscious. Adversities of early childhood due to mother's absence regarded as necessary condition for 'divine child' to attain highest good. Flood can be compensation of absence of feminine as well as to bring a new life. The notion of father·tree becomes a kind of life-boat has to do with union of opposite(vertical phallic tree and horizontal feminine boat). Ants and mosquitoes represent upper and lower level of unconsciousness, they mediate divine power. Therefore respecting insects means respecting unconscious, and reward of insects means salvation come from unconscious. The boy saved from the flood presents emergence of psychic energy in its latent unconscious condition to create mental dynamism. The old woman is Great Mother or anima, the controller or guider of unconscious. Working as servants can be an active service for the divine marriage. Trials of separating millet from sand, and finding right direction relate to separatio, means one needs to be separated from unconscious before conunctio, union of opposite. Two sets of couple becoming ancestor of man-kind has to do with number 4 (quaternity) as well as regeneration. Although the tale includes both positive couple (Mokdoryung, wise daugther in east room). and negative couple(shadow side of Mokdoryung, step daughter in west room)as ancestors of mankind, "Good" seems to be more valued than "evil".

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.1-16
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• 1985

This experiment was conducted to study sex expression and subsequent changes in protein and peroxidase after three cultivars of cucumber plants were treated with ethephon and gibberellin. The three cultivars of cucumber used in this study included 'Sayeup' (monoecious type), 'Sinrokdadaki' (gynoecious type), and 'Seonghowon' (intermediate type). The ethephon at 250 ppm and gibberellin at 100 ppm were treated at the 2-leaf and 4-leaf stages, and subsequent sex expression and changes in protein contents, peroxidase activities and isoperoxidase banding patterns by disc polyacrylamide gel electrophoresis were studied. The results can be summarized as follows: 1. Ethephon treatment slightly increased number of pistillate flowers and significantly decreased number of staminate flowers in the three cultivars, while gibberellin treatment significantly increased number of staminate flowers in both gynoecious 'Sinrokdadaki' and intermediate 'Seonghowon' and did not increase number of staminate flowers in monecious 'Sayeup' 2. There were some differences among three cultivars in protein contents, protein banding and isoperoxidase banding patterns of seeds and germinating seeds. However, it was not obvious to differentiate monoecious from gynoecious cultlvars by these characters. 3. Protein contents in the leaves. and stem apex after ethephon and gibberellin treatment increased gradually at the 2-leaf stage, but decreased at the 4-leaf stage. Protein contents in stem apex at the 4-leaf stage without treatment were much higher in 'Sinrokdadaki' and 'Seonghowon' than in monoecious 'Sayeup'. Protein contents in the stern apex at the 4-leaf stage were increased in the ethephon-treated monoecious 'Sayeup' and decreased in 'Sinrokdadaki' and 'Seonghowon' compared with untreated plants. 4. Peroxidase activities in the leaves and stem apex gradually decreased at the 2- leaf stage, but increased at the 4-leaf stage. Peroxidase activities in stern apex at the 4-leaf stage were significantly increased by ethephon treatment. 5. The number of protein bands in the three cuitivars after treatment gradually decreased in leaves and stem apex at the 2-leaf stage, but increased in the 4-leaf stage. The protein banding pat terns of stern apex of the ethephon-treated monoecious 'Sayeup' at the 4-leaf stage were gradually shifted to the banding.