• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1120-1126
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• 2007

This study was performed to screen probiotic bifidobacteria for their ability to bind and neutralize lipopolysaccharides (LPS) from Escherichia coli and to verify the relationship between LPS-binding ability, cell surface hydrophobicity (CSH), and inhibition of LPS-induced interleukin-8 (IL-8) secretion by HT-29 cells of the various bifidobacterial strains. Ninety bifidobacteria isolates from human feces were assessed for their ability to bind fluorescein isothiocyanate (FITC)-labeled LPS from E. coli. Isolates showing 30-60% binding were designated LPS-high binding (LPS-H) and those with less than 15% binding were designated LPS-low binding (LPS-L). The CSH, autoaggregation (AA), and inhibition of LPS-induced IL-8 release from HT-29 cells of the LPS-H and LPS-L groups were evaluated. Five bifidobacteria strains showed high levels of LPS binding, CSH, AA, and inhibition of IL-8 release. However, statistically significant correlations between LPS binding, CSH, AA, and reduction of IL-8 release were not found. Although we could isolate bifidobacteria with high LPS-binding ability, CSH, AA, and inhibition of IL-8 release, each characteristic should be considered as strain dependent. Bifidobacteria with high LPS binding and inhibition of IL-8 release may be good agents for preventing inflammation by neutralizing Gram-negative endotoxins and improving intestinal health.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1206-1215
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• 2016

Ginsenosides are the major active ingredients in ginseng used for human therapeutic plant medicines. One of the most well-known probiotic bacteria among the various strains on the functional food market is Lactobacillus rhamnosus GG. Biocatalytic methods using probiotic enzymes for producing deglycosylated ginsenosides such as Rd have a growing significance in the functional food industry. The addition of 2% cellobiose (w/v) to glucose-free de Man-Rogosa-Sharpe broths notably induced β-glucosidase production from L. rhamnosus GG. Enzyme production and activity were optimized at a pH, temperature, and cellobiose concentration of 6.0, 40℃, and 2% (w/v), respectively. Under these controlled conditions, β-glucosidase production in L. rhamnosus GG was enhanced by 25-fold. Additionally, whole-cell homogenates showed the highest β-glucosidase activity when compared with disrupted cell suspensions; the cell disruption step significantly decreased the β-glucosidase activity. Based on the optimized enzyme conditions, whole-cell L. rhamnosus GG was successfully used to convert ginsenoside Rb1 into Rd.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1422-1427
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• 2013

Scutellaria baicalensis (SB), a traditional herb with high pharmacological value, contains more than 10% flavone by weight. To improve the biological activity of flavones in SB, we aimed to enhance the bioconversion of baicalin (BG) to baicalein (B) and wogonoside (WG) to wogonin (W) in SB during fermentation using beta-glucuronidase produced from Lactobacillus brevis RO1. After activation, L. brevis RO1 was cultured in milk containing SB root extract with various carbon or nitrogen sources at $37^{\circ}C$ for 72 h. During fermentation, the growth patterns of L. brevis RO1 and changes in the flavone content were assessed using thin-layer chromatography and high-performance liquid chromatography. After 72 h of fermentation, the concentrations of B and W in the control group increased by only 0.15 and 0.12 mM, respectively, whereas they increased by 0.57 and 0.24 mM in the fish peptone group. The production of B and W was enhanced by the addition of 0.4% fish peptone, which not only improved the growth of L. brevis RO1 (p < 0.001) but also enhanced the bioconversion of flavones. In conclusion, the bioconversion of flavones in SB may provide a potential application for the enhancement of the functional components in SB.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.909-915
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• 2017

Bifidobacterium bifidum BGN4 (BGN4) has many proven beneficial effects, including antiallergy and anticancer properties. It has been commercialized and used in several probiotic products, and thus strain-specific identification of this strain is very valuable for further strain-dependent physiological study. For this purpose, we developed novel multiplex polymerase chain reaction (PCR) primer sets for strain-specific detection of BGN4 in commercial products and fecal samples of animal models. The primer set was tested on seven strains of B. bifidum and 75 strains of the other Bifidobacterium species. The BGN4-specific regions were derived using megaBLAST against genome sequences of various B. bifidum databases and four sets of primers were designed. As a result, only BGN4 produced four PCR products simultaneously whereas the other strains did not. The PCR detection limit using BGN4-specific primer sets was $2.8{\times}10^1CFU/ml$ of BGN4. Those primer sets also detected and identified BGN4 in the probiotic products containing BNG4 and fecal samples from a BGN4-fed animal model with high specificity. Our results indicate that the PCR assay from this study is an efficient tool for the simple, rapid, and reliable identification of BGN4, for which probiotic strains are known.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1717-1728
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• 2019

The gene encoding β-galactosidase was cloned from Bifidobacterium longum RD47 with combinations of several bifidobacterial promoters, and expressed in B. bifidum BGN4. Among the recombinant bifidobacteria, BGN4+G1 showed the highest β-galactosidase level, for which the hydrolytic activity was continuously 2.5 to 4.2 times higher than that of BGN4 and 4.3 to 9.6 times higher than that of RD47. The β-galactosidase activity of BGN4+G1 was exceedingly superior to that of any of the other 35 lactic acid bacteria. When commercial whole milk and BGN4+G1 were reacted, BGN4+G1 removed nearly 50% of the lactose in the milk by the 63-h time point, and a final 61% at 93 h. These figures are about twice the lactose removal rate of conventional fermented milk. As for the reaction of commercial whole milk and crude enzyme extract from BGN4+G1, the β-galactosidase of BGN4+G1 eliminated 51% of the lactose in milk in 2 h. As shown below, we also compared the strengths and characteristics of the strong bifidobacterial promoters reported by previous studies.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.592-594
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• 2008

The powers used in the robot drive motor system are mostly DC sources such as batteries. Even AC powers in some systems are generated from DC sources by the inverter. It is can be forecasted that the DC-link communications will be widely used invarious industrial application. In this paper a novel BLDC motor drive system by using DC-link communications is proposed. The characteristic of this system is the communication only needs 2 DC lines. There are not additional lines to translate the reference signals and the reliability of the system is enhanced especially in some badly circumstance. The number of lines can be least when applied in the multi motor control system and the slip ring design can be simplified when applied as rotation machine. The reasonableness of proposed motor system is clarified by the PSIM simulation and the hardware prototype.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.11
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• pp.943-951
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• 2012

In this paper, we propose a novel spectrum sensing scheme based on the order statistic for cooperative cognitive radio network in non-Gaussian noise environments. Specifically, we model the ambient noise as the bivariate isotropic symmetric ${\alpha}$-stable random variable, and then, propose a cooperative spectrum sensing scheme based on the order of observations and the generalized likelihood ratio test. From numerical results, it is confirmed that the proposed scheme offers a substantial performance improvement over the conventional scheme in non-Gaussian noise environments.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.202-205
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• 2005

The purpose of this work is to identify the characteristic of eye movement for visual training of the elderly. This investigation is to examine the relationship between the head and the eye motor system for the localization of visual target direction in three-dimensional space. All experiments were performed in a soundproof chamber. Twenty-one red LEDs (Light-Emitting Diode, Brightness: 20cd/$m^2$) arrayed in three lines on a half circle-surrounding panel are used. LEDs are horizontally 30 degree apart and vertically 20 degree apart from each other. The condition of stimulation is random and anti-saccade. Physiological parameter such as EOG (Electro-Oculography) was measured by BIOPAC system. We measure the mean latency time, which is the time from the start of visual stimulation to the response of the human body. The result shows that the mean latency time is short in the case of the condition of anti-saccade, the fixed head and a quarter visual stimulation. This finding can be used in developing programs for various visual improvements for the elderly by analyzing the characteristic of eye movement.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.1
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• pp.36-45
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• 2012

In this thesis, we propose an integrated simulation method of virtual tank simulators and an entity-based constructive simulation model for small unit tactical training. To do this, we first identify requirements for virtual-constructive integrated simulation in a synthetic environment. We then propose a virtual and constructive interoperation method where individual combat entities of virtual-constructive models are interacting with each others. We develop a method of aggregating individual combat entities into a larger combat unit and disaggregating an unit into entities from time to time. We also present a way of sharing synthetic environment information between the models. Finally, we suggest that for more effective interoperability, virtual and constructive models should be developed by using common combat object models. The proposed interoperation method can be extended to further live-virtual-constructive models.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.314-314
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• 1996

We investigate the scheduling problem for periodic job shops with blocking. We develop Petri net models for periodic job shops with finite buffers. A buffer control method would allow the jobs to enter the input buffer of the next machine in the order for which they are completed. We discuss difficulties in using such a random order buffer control method and random access buffers. We thus propose an alternative buffer control policy that restricts the jobs to enter the input buffer of the next machine in a predetermined order. The buffer control method simplifies job flows and control systems. Further, it requires only a cost-effective simple sequential buffer. We show that the periodic scheduling model with finite buffers using the buffer control policy can be transformed into an equivalent periodic scheduling model with no buffer, which is modeled as a timed marked graph. We characterize the structural properties for deadlock detection. Finally, we develop a mixed integer programming model for the no buffer problem that finds a deadlock-free optimal sequence that minimizes the cycle time.