• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.936-937
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• 2005

• Proceedings of the Korean Society of Life Science Conference
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• 2003.05a
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• pp.102-102
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• 2003

• Bulletin of the Korean Mathematical Society
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• v.60 no.3
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• pp.845-848
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• 2023

Erratum/Addendum to the paper "Biisometric operators and biorthogonal sequences" [Bull. Korean Math. Soc. 56 (2019), No. 3, pp. 585-596].

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.693-699
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• 2001

An intracellular levansucrase gene, lscR from Rahnella aquatilis ATCC 15552, was cloned and its nucleotide sequence was determined. Nucleotide sequence analysis of this gene revealed a 1,238 bp open reading frame coding for a protein of 415 amino acids. The levansucrase was expressed by using a T7 promoter in Escherichia coli BL21 (DE3) and the enzyme activity was detected in the cytoplasmic fraction. The optimum pH and temperature of this enzyme for levan formation was pH 6 and $30^{\circ}C$, respectively. The deduced amino acid sequence of the lscR gene showed a high sequence similarity (59-89%) with Gram-negative levansucrses, while the level of similarity with Gram-positive enzymes was less than 42%. Multiple alignments of levansucrase sequences reported from Gram-negative and Gram-positive bacteria revealed seven conserved regions. A comparison of the catalytic properties and deduced amino acid sequence of lscR with those of other bacterial levansucrases strongly suggest that Gram-negative and Gram-positive levansucrases have an overall different structure, but they have a similar structure at the active site.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.466-473
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• 2015

The juvenile red variant of the sea cucumber Stichopus japonicus is distributed worldwide. It is a valuable food source in Korea, China, and Japan. Major issues in farming the juvenile red variant sea cucumber include growth rates and disease resistance. In recent years, studies have focused on feed additives to enhance immune system and health. In this study, we used a common diet (CD), a nutritional diet (ND; mixed nutritional supplements), and an immunity diet (ID; mixed probiotics, spirulina, and levan) and compared the growth rates and immunity of juvenile red variant sea cucumbers fed the experimental diets for 12 weeks. The growth and survival rates in the ID group were significantly increased (P>0.05). This suggests that the feed additives positively influenced immunity and growth in the ID group. However, the immune activity was exhibit a stabilizing effect, and further investigation of immune effects is required.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.186-201
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• 2002

Fructan(Levan)은 식물체 및 미생물에서 발견되는 탄수화물로 이는 과당(fructose)이 $\beta$-2, 6 결합으로 연결되어 있는 polysaccaride 이다. 본 연구에서는 Fructan을 생성하는 미생물(Zymomonas mobilis)과 10% sucrose(기질), 1-2% 효모 추출물을 주성분으로 하는 배지를 사용하여 30-37$^{\circ}C$, pH 5.0-7.0에서 20-24시간 동안 배양한후 원심분리하여 균체를 제거하고 3배량의 알코올을 가하여 침전, 건조하여 얻은 Fructan의 화장품 원료로서의 가능성을 조사하였다. 보습효과에 있어서는 Hyaluronic acid와 유사하였으며, keratinocyte에 대한 세포증식 효과를 나타내었다. 또한 3-D culture에 의해 구축된 생인공 피부내에 0.05%의 sodium lauryl sulfate (SLS)를 사용하여 피부자극에 의한 초기 염증 반응을 유도한후 0.01mg/m1, 0.05mg/m1의 Fructan을 각각 처리하였을 때, SLS만을 처리한 생인공피부와 비교하여 세포증식효능을 보였고, SLS 자극물질로 유도된 전염증성 조절인자인 interleukin-l$\alpha$(IL-l$\alpha$)의 분비량을 조사 하였을때 0.01mg/ml, 0.05mg/ml의 Fructan을 처리한 생인공피부의 IL-l$\alpha$ 양이 Fructan을 처리하지 않은 것보다 상대적으로 감소하였다. 이러한 결과로 Fructan이 생인공 피부내 피부 세포의 증식효과를 나타낼 뿐만 아니라, 또한 피부자극물질에 의한 염증반응에 대해 자극완화효능이 있음을 알 수 있었다. 섬유아세포 및 동물을 이용한 안전성 시험에서도 독성이 없는 안전한 원료로 평가되었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.519-526
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• 2018

Fructan, a fructose homopolymer, is found in various foods, including onion, garlic, chicory, Jerusalem artichoke, banana, and Cheonggukjang. This study aimed to quantitatively analyze both levan-type and insulin-type fructan using acid analysis and enzyme treatment. In order to analyze fructan contents, we applied optimized conditions to various fructan-rich foods using products from 2017. In the case of oxalic acid hydrolysis, fructose concentrations increased as oxalic acid concentration increased. Inulinase treatment was better than invertase treatment in terms of fructose liberation from fructan. We applied three different methods to fructan-rich foods, including onion, garlic, banana, and Cheonggukjang and found that fructose released from fructan-rich foods was the highest in oxalic acid hydrolysis among three different methods. Except for Cheonggukjang, inulinase treatment produced better results in terms of fructose contents than invertase treatment. From our study, estimated daily fructan intakes by Koreans were 1,172~3,402 mg from onion and garlic. In conclusion, we believe that information on fructan-rich foods may be helpful to understand their roles in the human digestive system.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.527-529
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• 2003

A fructosyltransferase from Leuconostoc mesenteroides TL1 was purified. The molecular mass of the enzyme was estimated to be 38 kDa based on the activity staining. The pH and temperature optima of the enzyme were 6.3 and $40^{\circ}C$, respectivly. Structural analysis of the polymer prepared from sucrose by the enzyme was determined by NMR Spectroscopy: It shows the heterogeneous linkages of levan-like fructan and dextran-like glucan.

• Bulletin of the Korean Mathematical Society
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• v.42 no.1
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• pp.169-177
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• 2005

A Hilbert Space operator T is of class Q if $T^2{\ast}T^2-2T{\ast}T + I$ is nonnegative. Every paranormal operator is of class Q, but class-Q operators are not necessarily normaloid. It is shown that if a class-Q contraction T has no nontrivial invariant subspace, then it is a proper contraction. Moreover, the nonnegative operator Q = $T^2{\ast}T^2-2T{\ast}T + I$ also is a proper contraction.

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.130.2-130.2
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• 2003