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Pohang, South Korea

Eom H.-J.,Chungbuk National University | Cho S.K.,Chungbuk National University | Park M.S.,Anyang Technical College | Ji G.E.,Seoul National University | Han N.S.,Chungbuk National University
Biotechnology and Bioprocess Engineering | Year: 2010

Leuconostoc spp. are important lactic acid bacteria for the fermentation of foods, and they are regarded as potential food-grade hosts for protein expression. The aim of this study was to develop a broad-host-range shuttle vector for the genetic study and biotechnological evaluation of this genus by using a Leuconostoc-derived plasmid. A cryptic plasmid, pCB18, was obtained from Leuconostoc citreum CBNU75; its nucleotide sequence was 1,821 bp long and had only 39.2% G+C content. A Leuconostoc-Escherichia coli shuttle vector, pLeuCM, was constructed by combining pCB18 and pEK104, and it was successfully replicated in both E. coli and L. citreum. The shuttle vector was replicated by following the rolling circle replication mechanism, and it showed over 80% segregational stability after 100 generations of cell division. The β-galactosidase gene of Lactobacillus plantarum was subcloned into pLeuCM, and this construct was successfully expressed in L. citreum. The pLeuCM plasmid was replicated in L. citreum, L. mesenteroides, Lb. plantarum, Lb. reuteri, Lactococcus lactis, Streptococcus thermophilus, Weissella confusa, and Oenococcus oeni. These results demonstrate that pLeuCM can be used as a potential gene-delivery tool for many lactic acid bacteria. © 2010 The Korean Society for Biotechnology and Bioengineering and Springer-Verlag.

Lee H.-H.,Anyang Technical College | Lee W.-S.,Yonsei University
Knowledge and Information Systems | Year: 2010

Query processing for a data stream should also be continuous and rapid. This article proposes a novel approach for consistent collective evaluation of multiple continuous queries for filtering two different types of data streams: a relational stream and an XML stream. The proposed approach commonly provides region-based selection constructs: an attribute selection construct for relational queries and a path selection construct for XPath queries. Both collectively evaluate the selection predicates of the same attribute (path), based on the precomputed matching results of the queries in each of the disjoint regions divided by the selection predicates. The performance experiments show that the proposed approach is practically more efficient and stable than other approaches at run-time. © Springer-Verlag London Limited 2009.

Kim J.Y.,Seoul National University | Wang Y.,Seoul National University | Park M.S.,Anyang Technical College | Ji G.E.,Seoul National University | Ji G.E.,Research South, Inc.
Journal of Microbiology and Biotechnology | Year: 2010

The different cleavage patterns of pYBamy59 plasmid isolated from E. coli DH5α and B. longum MG1 by the cell extract of B. longum MG1 suggested that the main reason for its low transformation efficiency was related to the restriction modification (R-M) system. To confirm the correlation between the R-M system and transformation efficiency, in vitro methylation and site-directed mutagenesis were performed in pYBamy59. Sequence analysis of pYBamy59 fragments digested by the cell extract of B. longum MG1 revealed that all fragments were generated by restriction of the sequence recognized by SacII endonuclease. When pYBamy59 from E. coli was methylated in vitro by CpG or GpC methyltransferase, it was protected from SacII digestion. Site-directed mutagenesis, which removed SacII sites from pYBamy59, or in vitro methylation of pYBamy59 showed 8- to 15-fold increases in the transformation efficiency over intact pYBamy59. Modification of the SacII-related R-M system in B. longum MG1 and in vitro methylation in pYBamy 59 can improve the transformation efficiency in this strain. The results showed that the R-M system is a factor to limit introduction of exogenous DNA, and in vitro modification is a convenient method to overcome the barrier of the R-M system for transformation. © The Korean Society for Microbiology and Biotechnology.

Kim J.S.,Seoul National University | Jeon W.J.,Seoul National University | You H.J.,Seoul National University | Park M.S.,Seoul National University | And 4 more authors.
Food Science and Biotechnology | Year: 2010

Control of postprandial glucose level is important in the management of diabetes. Thus, carbohydratehydrolyzing enzymes have been the targets to delay absorption of glucose. In this study, water extracts of Rubi Fructus (WERF) showed inhibition on both α-glucosidase from baker's yeast and α-amylase from porcine pancreas. The IC 50 value of WERF on α-amylase was 59.4 μg/mL. The inhibitory activities of WERF were considerably decreased during incubation at 25, 37, and 45°C for 24 hr. For the assessment of the active components tannin fraction was separated from WERF using Sephadex LH-20. Whereas LH-unbound fraction showed minimal inhibition on α-amylase LH-bound fraction containing enriched tannins showed higher inhibition (IC 50 8.9 μg/ mL) than WERF (IC 50 59.4 μg/mL). These results suggested that tannin enriched fraction of WERF contributed to the inhibitory activity of WERF on α-amylase. © KoSFoST and Springer 2010.

Shin D.,Chung - Ang University | Kim J.,Anyang Technical College | Ryu S.,Chung - Ang University | Park S.-K.,Chung - Ang University
Studies in Computational Intelligence | Year: 2011

Next generation mobile communication will be developed by service-driven approach to realize human-centric mobile convergence services. As a preliminary research work on next generation mobile communication system, we have developed the scenario based service analysis process (2SAP) framework to derive core service technologies and functionalities. In this paper, we propose the next generation mobile convergence service business model creation methodology based on the 2SAP research framework. To achieve this goal, we first establish a service model which contains several components such as infrastructures, operations and service provisioning process. Then, after defining necessary components of business model including actors, their relationships, and roles, the next generation mobile services and business models can be created by including value flows to the developed service model. © 2011 Springer-Verlag Berlin Heidelberg.

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