• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1728-1733
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• 2015

This study was done to establish a mouse model for catheter-related biofilm infection suitable to bioluminescence imaging (BLI). Biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) Xen5 grown on catheter disks in vitro and in an implanted mouse model was real-time monitored during a 7-day study period using BLI. The numbers of integrated brightness (IB) and viable bacterial count (VBC) in the biofilm disks in vitro were highest at 24 h after inoculation; the IB of biofilm in vivo was increased until 24 h after implantation. A statistical correlation was observed between IB and VBC in vitro by linear regression analysis. The actual VBC value in vivo can be estimated accurately by IB without sacrifice. In addition, we monitored the change in white blood cells (WBCs) during infection. The number of WBCs on day 7 was significantly higher in the infection group than in the control group. This study indicates that BLI is a simple, fast, and sensitive method to measure catheter biofilm infection in mice.

• Food Science of Animal Resources
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• v.31 no.4
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• pp.513-520
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• 2011

In order to develop a new starter culture for fermented milk, Lactobacillus fermentum LC272 was isolated from raw milk and its physiological characteristics were investigated. The vitamin $K_2$ concentration of L. fermentum LC272 was $184.94{\mu}g/L$ in Rogosa medium and $63.93{\mu}g/L$ in the reconstituted skim milk. The optimum growth temperature for L. fermentum LC272 was determined to be $40^{\circ}C$ and it took 24 h for the pH to reach 5.2 under this condition. L. fermentum LC272 was more sensitive to rifampicin relative of the other 15 different antibiotics tested, and showed most resistance to streptomycin. L. fermentum LC272 showed higher activities to leucine arylamidase and acid phosphatase. It was comparatively tolerant to bile juice and acid and displayed high resistance against Salmonella Typhimurium and Staphylococcus aureus with rates of 82.9 and 86.3% respectively. These results demonstrated that L. fermentum LC272 could be an excellent starter culture for fermented milk with high levels of vitamin $K_2$ production.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2326-2330
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• 2014

A carbazole-based Schiff base CB2 was synthesized and applied as a highly selective and sensitive fluorescent probe for $Cu^{2+}$ in $H_2O$-DMSO (8/2, v/v, pH = 7.4) solution. CB2 exhibits an excellent selectivity to $Cu^{2+}$ over other examined metal ions with a prominent fluorescence "turn-on" at 475 nm. CB2 and $Cu^{2+}$ forms a 1:2 binding ratio complex with detection limit of $9.5{\mu}M$. In addition, the $Cu^{2+}$ recognition process is hardly interfered by other examined metal ions.

• BMB Reports
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• v.31 no.2
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• pp.144-148
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• 1998

A bifunctional catalase-peroxidase, designated catalase-2, of a UV resistant Deinococcus radiophilus was purified to electrophoretic homogeneity by both chromatographic and electrophoretic methods. Its molecular weight was 310 kDa and composed of a tetramer of 80 kDa subunits. The catalase-2 exerted its optimal activity at $30^{\circ}C$ and around pH 9. Its $K_m$ value for $H_{2}0_{2} $ was about 10 mM. It showed the typical ferric heme spectrum with maximum absorption at 403 nm which shifted to 419 nm in the presence of cyanide. The ratio of A40i' A2S0 was 0.48. Fifty percent inhibition of the enzyme activity was observed at $4.6{\times}10^{-6}$, $7.7{\times}10^{-6}$, and $3.0{\times}10^{-6}$ M of NaCN, $NaN_3$, and $NH_{2}OH$, respectively. The enzyme was thermostable and not sensitive to 3-amino-1,2,4-triazole. Treatment of the enzyme with ethanol-chloroform caused a partial loss (30%) of its activity. The catalase-2 was distinct from the Deinococcal bifunctional catalase-3 in a number of properties, particularly in its molecular structure and substrate affinity.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.481-485
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• 2010

Lactobacillus plantarum strain KK3 with tannase activity was isolated from Gochunipkimchi (red pepper leaf kimchi) and showed a high antagonistic activity against five kinds of food pathogens. Strain KK3 secreted antibacterial compound into culture medium and 24-h culture in MRS broth at $30^{\circ}C$ was enough for the antibacterial compound production. The crude antibacterial compound prepared from culture supernatant inhibited the growth of some Gram-negative bacteria and Bacillus cereus but not Listeria monocytogenes. The antibacterial activity was sensitive to proteinase K treatment, confirming its proteinaceous nature (bacteriocin). The crude bacteriocin was active in the pH range 3.5-8.5 and extremely stable after 15 min of heat treatment at $121^{\circ}C$. The strain KK3 produced equally active bacteriocin in Chinese cabbage juice as it produced in MRS broth.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.159-163
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• 2013

A new Rhodamine B hydrazide hydrazone 1 has been synthesized and investigated as a colorimetric and fluorescent "off-on" sensor for the recognition of $Cu^{2+}$ in $CH_3CN/H_2O$ (1:1, v/v, HEPES 10 mM, pH = 7.0) solution. Sensor 1 displayed highly selective, sensitive and rapid recognition behavior toward $Cu^{2+}$ among a range of biologically and environmentally important metal ions. Sensor 1 bind $Cu^{2+}$ via a 1:1 stoichiometry with an association constant of $1.92{\times}10^6\;M^{-1}$, and the detection limit is evaluated to be $7.96{\times}10^{-8}\;M$. The $Cu^{2+}$ recognition event is reversible and is barely interfered by other coexisting metal ions.

• Progress in Superconductivity and Cryogenics
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• v.22 no.4
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• pp.1-5
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• 2020

Heart consists of myocardium cells and the electrophysiological activity of the cells generate magnetic fields. By measuring this magnetic field, magnetocardiogram (MCG), functional diagnosis of the heart diseases is possible. Since the strength of the MCG signals is weak, typically in the range of 1-10 pT, we need sensitive magnetic sensors. Conventionally, superconducting quantum interference devices (SQUID)s were used for the detection of MCG signals due to its superior sensitivity to other magnetic sensors. However, drawback of the SQUID is the need for regular refill of a cryogenic liquid, typically liquid helium for cooling low-temperature SQUIDs. Efforts to eliminate the need for the refill in the SQUID system have been done by using cryocooler-based conduction cooling or use of non-cryogenic sensors, or room-temperature sensors. Each sensor has advantage and disadvantage, in terms of magnetic field sensitivity and complexity of the system, and we review the recent trend of MCG technology.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.1022-1029
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• 2018

Tuberculosis (TB) remains a serious health issue around the word. Adenovirus (Ad)-based vaccine and modified vaccinia virus Ankara (MVA)-based vaccine have emerged as two of the most promising immunization candidates over the past few years. However, the performance of the homologous and heterologous prime-boost immunization regimens of these two viral vector-based vaccines remains unclear. In the present study, we constructed recombinant Ad and MVA expressing an Ag85B-TB10.4 fusion protein (AdH4 and MVAH4) and evaluated the impact of their different immunization regimens on the humoral and cellular immune responses. We found that the viral vector-based vaccines could generate significantly higher levels of antigen-specific antibodies, $IFN-{\gamma}$-producing splenocytes, $CD69^+CD8^+$ T cells, and $IFN-{\gamma}$ secretion when compared with bacillus Calmette-$Gu{\acute{e}}rin$ (BCG) in a mouse model. AdH4-containing immunization regimens (AdH4-AdH4, AdH4-MVAH4, and MVAH4-AdH4) induced significantly stronger antibody responses, much more $IFN-{\gamma}$-producing splenocytes and $CD69^+CD8^+$ T cells, and higher levels of $IFN-{\gamma}$ secretion when compared with the MVAH4-MVAH4 immunization regimen. The number of $IFN-{\gamma}$-producing splenocytes sensitive to $CD8^+$ T-cell restricted peptides of Ag85B (9-1p and 9-2p) and Th1-related cytokines ($IFN-{\gamma}$ and $TNF-{\alpha}$) in the AdH4-MVAH4 heterologous prime-boost regimen immunization group was significantly higher than that in the other viral vector-based vaccine- and BCG-immunized groups, respectively. These results indicate that an immunization regimen involving AdH4 may have a higher capacity to induce humoral and cellular immune responses against TB in mice than that by regimens containing BCG or MVAH4 alone, and the AdH4-MVAH4 prime-boost regimen may generate an ideal protective effect.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1722-1728
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• 2012

During the analyzing processes of the compounds, some researchers are puzzled by the analytical signals for some TSNAs (with or without splitting peaks at various pHs and temperatures). In this work, a detailed theoretical study of structural and thermal properties of the $E/Z$ isomers of TSNAs and the corresponding protonated structures was performed using DFT methods. The calculations showed that the $E$ isomers are almost stable than $Z$ isomers, while the $Z$ isomers would be more stable when in protonation. The calculated results predicted the possibility of separation of their $E$ and $Z$ isomer forms and also showed that protonation affects the dipole moment of molecules significantly (0.1-0.5 to 0.7-2.1 Debye). The calculations agreed well with the experiments that the split-up of the HPLC signal for TSNAs into two peaks are very sensitive to the pH and temperature of the mobile-phase.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1215-1220
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• 2011

An electrochemically-modified electrode [P(EDOP-SWNTs)/GCE] was prepared by electropolymerization of 3,4-ethylenedioxy pyrrole (EDOP) single-walled carbon nanotubes (SWNTs) on the surface of a glassy carbon electrode (GCE) and characterized by SEM, CV, and DPV. This modified electrode was employed as an electrochemical biosensor for the selective determination of serotonin concentrations at pH 7.4 and exhibited a typical enhanced effect on the current response of serotonin with a lower oxidation overpotential. The linear response was in the range of $1.0{\times}10^{-7}$ to $1.0{\times}10^{-5}$ M, with a correlation coefficient of 0.998 on the anodic current. The lower detection limit was calculated as 5.0 nM. Due to the relatively low currents and difference of potentials in the electrochemical responses of uric acid (UA), ascorbic acid (AA), and dopamine (DA), the modified electrode was a useful and effective sensing device for the selective and sensitive serotonin determination in the presence of UA, AA, and DA.