• Title/Summary/Keyword: natural sciences and engineering

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Marine Bioprocess Engineering: Building Bridges from Discovery to Commercialization of Marine Natural Products

  • Zhang, Wei;Jin, Meifeng;Yu, Xinju;Deng, Maicun;Yuan, Quan
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.137-140
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    • 2000
  • Numerous novel marine natural products have been discovered and isolated from varied marine organisms by the diligent bio-prospectors over the past decades. An assessment of the current status of commercial development of these natural compounds indicates only minimal commercialization due to the lack of sustainable supply. To bridge the gaps between discovery and commercialization of these tantalizing bioactive compounds, marine bioprocess engineering is the key for its success. The problems, challenges and opportunities for marine bioprocess engineers are examined for the timely transformation of the discovery into commercial reality. Marine bioprocess engineers will find it the most rewarding practice of their expertise in diving into the ocean.

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Crystal structure and functional analysis of the surE protein identify a novel phosphatase family

  • Lee, Jae-Young;Kwak, Jae-Eun;Suh, Se-Won
    • Proceedings of the Korean Biophysical Society Conference
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    • 2001.06a
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    • pp.19-19
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    • 2001
  • The genome sequencing has revealed a large number of proteins of unknown or little characterized functions that have been well conserved during evolution. It remains a great challenge to decipher the molecular and physiological functions of these proteins. One example of the evolutionarily conserved protein family with little understood function is the surE family.(omitted)

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Molecular Structure of PCR Cloned PHA Synthase Genes of Pseudomonas putida KT2440 and Its Utilization for Medium-Chain Length Polyhydroxyalkanoate Production

  • Kim, Tae-Kwon;Shin, Hyun-Dong;Seo, Min-Cheol;Lee, Jin-Nam;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.13 no.2
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    • pp.182-190
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    • 2003
  • A new phaC gene cluster encoding polyhydroxyalkanoate (PHA) synthase I PHA depolymerase, and PHA synthase II was cloned using the touchdown PCR method, from medium-chain length (mcl-) PHA-producing strain Pseudomonas putida KT2440. The molecular structure of the cloned phaCl gene was analyzed, and the phylogenic relationship was compared with other phaCl genes cloned from Pseudomonas species. The cloned phaCl gene was expressed in a recombinant E. coli to the similar level of PHA synthase in the parent strain P. putida KT2440, but no significant amount of mcl-PHA was accumulated. The isolated phaCl gene was re-introduced into the parent strain P. putida KT2440 to amplify the PHA synthase I activity, and the recombinant P. purida accumulated mcl-PHA more effectively, increasing from 26.6 to $43.5\%$. The monomer compositions of 3-hydroxylalkanoates in mcl-PHA were also modified significantly in the recombinant P. putida enforcing the cloned phaCl gene.

Functional Characteristics of Cyclodextrin Glucanotransferase from Alkalophilic Bacillus sp. BL-31 Highly Specific for Intermolecular Transglycosylation of Bioflavonoids

  • Go, Young-Hoon;Kim, Tae-Kwon;Lee, Kwang-Woo;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.17 no.9
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    • pp.1550-1553
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    • 2007
  • The functional characteristics of a ${\beta}$-cyclodextrin glucanotransferase (CGTase) excreted from alkalophilic Bacillus sp. BL-31 that is highly specific for the intermolecular transglycosylation of bioflavonoids were investigated. The new ${\beta}$-CGTase showed high specificities for glycosyl acceptor bioflavonoids, including naringin, rutin, and hesperidin, and especially naringin. The transglycosylation of naringin into glycosyl naringin was then carried out under the conditions of 80 units of CGTase per gram of maltodextrin, 5 g/l of naringin, 25 g/l of maltodextrin, and 1 mM $Mn^{2+}$ ion at $40^{\circ}C$ for 6 h, resulting in a high conversion yield of 92.1%.

Interfacial Dzyaloshinskii-Moriya interaction in W/CoFeB/MgO films with perpendicular magnetic anisotropy tuned by variation of the W thicknesses and annealing temperatures (수직자기이방성을 나타내는 W/CoFeB/MgO 박막에서 W두께와 열처리 온도에 따른 계면 드잘로신스키-모리야 상호작용 변화 분석)

  • Kim, Gyu Won;Kim, Yong Jin;Cha, In Ho;Samardak, Alexander S.;Pal, Bappaditya;Kolesnikov, Alexander G.;Ognev, Alexey V.;Sadovnikov, Alexandr V.;Nikitov, Sergey A.;Kim, Young Keun
    • Proceedings of the Korean Magnestics Society Conference
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    • 2017.05a
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    • pp.106-107
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    • 2017
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Effect of Cyclic GMP on Human Cytomegalovirus Gene Expression (Human Cytomegalovirus 유전자 발현에 Cyclic GMP의 영향)

  • Yoon, Joo-Hyun;Lee, Gyu-Cheol;Song, Byung-Hak;Kim, Young-Jin;Lee, Chan-Hee
    • The Journal of Korean Society of Virology
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    • v.29 no.4
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    • pp.261-269
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    • 1999
  • The relationship between second messenger cGMP and human cytomegalovirus (HCMV) replication was investigated. First, the intracellular level of cGMP ([cGMP]i) in HCMV-infected cells was measured. The [cGMP]i increased at early times after HCMV infection, reached maximum level at 12 hr and returned to basal level at 24 hr after virus infection, while [cGMP]i in mock-infected cells remained relatively unchanged. Increasing [cGMP]i resulted in enhanced transcription of HCMV major immediate early gene. For early gene expression, cGMP had varying effect. Expression of 1.2 kb RNA decreased and 2.2 kb RNA increased with increasing cGMP, while 2.7 kb RNA gene expression was not affected. HCMV early genes are regulated by immediate early gene, and the effect of cGMP on the regulatory effect of major immediate early gene on early genes was investigated. In the absence of cGMP, major immediate early gene repressed 2.7 kb RNA gene expression, while 1.2 kb RNA and 2.2 kb RNA early genes were not significantly affected. In the presence of $1\;{\mu}M$ cGMP, however, major immediate early gene stimulated the expression of three early genes.

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Influence line- model correction approach for the assessment of engineering structures using novel monitoring techniques

  • Strauss, Alfred;Wendner, Roman;Frangopol, Dan M.;Bergmeister, Konrad
    • Smart Structures and Systems
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    • v.9 no.1
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    • pp.1-20
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    • 2012
  • In bridge engineering, maintenance strategies and thus budgetary demands are highly influenced by construction type and quality of design. Nowadays bridge owners and planners tend to include life-cycle cost analyses in their decision processes regarding the overall design trying to optimize structural reliability and durability within financial constraints. Smart permanent and short term monitoring can reduce the associated risk of new design concepts by observing the performance of structural components during prescribed time periods. The objectives of this paper are the discussion and analysis of influence line or influence field approaches in terms of (a) an efficient incorporation of monitoring information in the structural performance assessment, (b) an efficient characterization of performance indicators for the assessment of structures, (c) the ability of optimizing the positions of sensors of a monitoring system, and (d) the ability of checking the robustness of the monitoring systems applied to a structure. The proposed influence line- model correction approach has been applied to an integrative monitoring system that has been installed for the performance assessment of an existing three-span jointless bridge.

Morphological Variation of Enterobacter sp. BL-2 in Acetate-mediated pH Environment for Excretive Production of Cationic Microbial Polyglucosamine Biopolymer

  • Son, Mi-Kyung;Hong, Soo-Jung;SaGong, Kuk-Hwa;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.18 no.1
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    • pp.104-106
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    • 2008
  • Enterobacter sp. BL-2 excretively produced a unique cationic polyglucosamine biopolymer PGB-1 comprised of more than 95% D-glucosamine in an acetate-mediated culture condition. The excretion of the biopolymer PGB-1 was closely associated with the cellular morphology of Enterobacter sp. BL-2, a feature highly dependable on the pH of the medium. The initially formed uneven and irregular surface cells were aggregated into the cell-biopolymer network structure connected by the adhesion modules of the cell-bound biopolymer. The excretive production of the biopolymer PGB-1 coincided with the disruption of the cell-biopolymer network, most actively at the medium pH of 8.0.