• Microbiology and Biotechnology Letters
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• v.48 no.1
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• pp.24-31
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• 2020

Five genes (mxbDM, mxcQE and mxaB) are responsible for the transcription of methanol oxidation genes in Methylobacterium strains. Among these, MxbDM and MxcQE constitute the two-component system (TCS) regulating methanol metabolism. In this study, we integrated the methanol-sensing domain of MxbD and MxcQ with the EnvZ/OmpR from Escherichia coli. The domain-swapping strategy resulted in chimeric histidine kinases (HK's) MxbDZ and MxcQZ AM1 containing recombinant E. coli. Real-time quantitative PCR was used to monitor OmpC expression mediated by the chimeric HK and response regulator (RR) OmpR. Further, an ompC promoter based fluorescent biosensor for sensing methanol was developed. GFP fluorescence was studied both qualitatively and quantitatively in response to environmental methanol. GFP measurement also confirmed ompC expression. Maximum fluorescence was observed at 0.05% methanol and 0.01% methanol using MxbDZ and MxcQZ AM1, respectively. Thus the chimeric HK containing E. coli were found to be highly sensitive to methanol, resulting in a rapid response making them an ideal sensor.

• Animal Bioscience
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• v.35 no.8
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• pp.1279-1288
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• 2022

Objective: The aim of this study was to investigate antioxidant activities of cinnamon (Cinnamomum cassia) extracts (extracted with different solvents) at various concentrations and to determine product quality of raw chicken patties added with different levels of cinnamon powder (CP) and oyster mushroon powder (OMP) during storage. Methods: After cinnamon was made into oven dried CP and extracted with water and different levels (50%, 80%, and 100%) of ethanol, antioxidant activities of these extracts were determined. CP and OMP were combined at different levels and added to raw chicken patties. Physicochemical properties and microbial counts were measured during refrigerated storage. Results: Cinnamon ethanol (80%) extract showed the highest (p<0.05) by 2,2-diphenyl-1picrylhydrazyl-radical scavenging activity and reducing power. Cinnamon water extract (CWE) had the highest iron chelating ability (p<0.05), while CP 100% ethanol extract had the highest content of total phenolic compound. Then, CP and OMP were applied to chicken patties at different levels (0.1% to 0.2%). After the addition of CPs, pH, L* (lightness), 2-thiobarbituric acid reactive substance, and volatile basic nitrogen values were decreased, whereas a* (redness) and b* (yellowness) values were increased. Microbial counts of total bacteria and Enterobacteriaceace were decreased with the addition of CP 0.2% regardless of the OMP level. Conclusion: The addition of CP in combination with OMP can increase the shelf-life of chicken patties during storage.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.273-277
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• 2006

To investigate the antigenicity and protective immunity of outer membrane protein H (OmpH) in Pasteurella multocida D:4, the recombinant OmpH protein was produced in Escherichia coli. The truncated and Trx-fused form of recombinant OmpH (53 kDa) was purified, and used as an antigen in the immunization and challenge experiment. The immunized mice with the recombinant OmpH produced a high-titer antibody, and had protective immunity against P. multocida as same level as the mice immunized with formalin-killed whole cell.

• Journal of Life Science
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• v.18 no.2
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• pp.241-248
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• 2008

This study has been carried out to secretion antibodies for the purpose of preventing the infection of Helicobacter pylori and using them as a supplement for treatment. This experiments have been separated antigens from H. pylori and observed into antibody production and the agglutination of H. pylori for the separated antigens. As major antigenic proteins separated from H. pylori, the following could be verified: 12 kinds of band for whole cell (WC), seven kinds of band for outer membrane protein (OMP), three kinds of band for crude urease, and one kind of band for lipopolysaccharide (LPS). The IgG anti-H. pylori antibody of separated antigens showed $77.9{\pm}6.4{\mu}g/ml$ for we (L), $84.9{\pm}6.4{\mu}g/ml$ for OMP, and $123.8{\pm}2.9{\mu}g/ml$ for crude urease, at the same antigen concentration of $20{\mu}g/100ull$, which showed the most at the crude urease. And it turned out that the IgA antibodies were generated with $2.5{\pm}0.32{\mu}g/ml$ for WC (L), $2.0{\pm}0.43{\mu}g/ml$ for OMP, and $1.3{\pm}0.25{\mu}g/ml$ for crude urease, which demonstrated the most for WC (L) antigens. As a result of verifying the immunogenecity of antigenic protein through the Western blotting, major antigenic substances could be confirmed as follows: 10 kinds for WC, six kinds for OMP and three kinds for crude urease. The agglutination values on the H. pylori of the antibody were $2^5,\;2^5,\;2^6\;and\;2^7$ at the antigen serums of anti-WC (H), anti-WC (L), anti-OMP and anti-crude urease, respectively, which indicated the highest for the antigen serum of anti-crude urease. The urease activation-inhibiting absorbance of antigen serum created by each antigen was $0.14{\pm}0.01$ for WC (H), $0.16{\pm}0.01$ for WC (L), $0.18{\pm}0.03$ for OMP, and $0.18{\pm}0.04$ for urease, demonstrating a significant inhibiting effect, compared with $0.26{\pm}0.02$ of the control group.

• Journal of Life Science
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• v.11 no.2
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• pp.94-98
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• 2001

Type I signal peptidase cleaves the signal sequence from the amino terminus of membrane and secreted proteins afters these protein insert across the membrane. This enzyme serves as a potential target for the development of novel antibacterial agents due to its unique physiological and biochemical properties. Despite considerable research, the signal peptidase assay still remains improvement to provide further understanding of the mechanism and high-throughput inhibitor screening of this enzyme. In this paper, three known signal peptidase assays are tested with an E. coli D276A mutant signal peptidase to distinguish the sensitivity of each assays. In vitro assay using the procoat synthesized by in vitro transcription translation shows that the D276A signal peptidase I was inactive while in vivo processing of pro-OmpA expressed in the temperature-sensitive E. coli strain IT41 as well as in vitro assay using pro-OmpA nuclease A substrate show that D276A signal peptidase I has activity like wild-type signal peptidase. These results suggest that in vitro assay using the pro-OmpA nuclease A and in vivo pro-OmpA processing assay are more sensitive monitors than in vitro assay using the pro-coat. In conculsion, caution should be used when interpreting the in vitro results using the procoat.

• Journal of Veterinary Science
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• v.22 no.2
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• pp.15.1-15.13
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• 2021

Background: Attenuated Salmonella strain can be used as a vector to transport immunogens to the host antigen-binding sites. Objectives: The study aimed to determine the protective efficacy of attenuated Salmonella strain expressing highly conserved Brucella immunogens in goats. Methods: Goats were vaccinated with Salmonella vector expressing individually lipoprotein outer-membrane protein 19 (Omp19), Brucella lumazine synthase (BLS), proline racemase subunit A (PrpA), Cu/Zn superoxide dismutase (SOD) at 5 × 10⁹ CFU/mL and challenge of all groups was done at 6 weeks after vaccination. Results: Among these vaccines inoculated at 5 × 10⁹ CFU/mL in 1 mL, Omp19 or SOD showed significantly higher serum immunoglobulin G titers at (2, 4, and 6) weeks post-vaccination, compared to the vector control. Interferon-γ production in response to individual antigens was significantly higher in SOD, Omp19, PrpA, and BLS individual groups, compared to that in the vector control (all p < 0.05). Brucella colonization rate at 8 weeks post-challenge showed that most vaccine-treated groups exhibited significantly increased protection by demonstrating reduced numbers of Brucella in tissues collected from vaccinated groups. Real-time polymerase chain reaction revealed that Brucella antigen expression levels were reduced in the spleen, kidney, and parotid lymph node of vaccinated goats, compared to the non-vaccinated goats. Besides, treatment with vaccine expressing individual antigens ameliorated brucellosis-related histopathological lesions. Conclusions: These results delineated that BLS, Omp19, PrpA, and SOD proteins achieved a definite level of protection, indicating that Salmonella Typhimurium successfully delivered Brucella antigens, and that individual vaccines could differentially elicit an antigen-specific immune response.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1557-1564
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• 2014

In this paper, we propose a signal detection technique based on the parallel orthogonal matching pursuit (POMP) is proposed for generalized shift space keying (GSSK) systems, which is a modified version of the orthogonal matching pursuit (OMP) that is widely used as a greedy algorithm for sparse signal recovery. The signal recovery problem in the GSSK systems is similar to that in the compressed sensing (CS). In the proposed POMP technique, multiple indexes which have the maximum correlation between the received signal and the channel matrix are selected at the first iteration, while a single index is selected in the OMP algorithm. Finally, the index yielding the minimum residual between the received signal and the M recovered signals is selected as an estimate of the original transmitted signal. POMP with Quantization (POMP-Q) is also proposed, which combines the POMP technique with the signal quantization at each iteration. The proposed POMP technique induces the computational complexity M times, compared with the OMP, but the performance of the signal recovery significantly outperform the conventional OMP algorithm.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.674-678
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• 2002

Yersinia enterocolitica causes various diseases in humans, including enteritis. The onset of such diseases is closely related with the expression of important virulence factors, particularly outer membrane proteins (OMPs). The expression of OMPs depends on several factors, including temperature, and origin, biotype and serotype of the bacteria. Recently, concerns over food safety have increased along with the demand for the development of sensitive, rapid, and pathogen-specific detection methods. To develop a suitable detection method for Y. enterocolitica isolated from Korean moutainspring water and pig feces, the OMP expression patterns were analyzed phenotypically and immunologically using 12 representative strains from 51 Y. enterocolitica Korean isolates. A 38-kDa OMP was commonly observed in all strains. However, additional OMPs were also observed in different biotypes and serotypes as well as bacterial origins, by incubating Y. enterocolitica at a low temperature. The specificity of the 38-kDa OMP was confirmed by a Western blot analysis with antisera against Y. enterocolitica and Brucella abortus. The results, therefore, indicate that the 38-kDa OMP could be used as a marker for detecting Y. enterocolitica in the environment or for seromonitoring.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.954-963
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• 2012

As a greedy algorithm reconstructing the sparse signal from underdetermined system, orthogonal matching pursuit (OMP) algorithm has received much attention. In this paper, we multiple candidate matching pursuit (MuCaMP), which builds up candidate support set in every iteration and uses the minimum residual at last iteration. Using the restricted isometry property (RIP), we derive the sufficient condition for MuCaMP to recover the sparse signal exactly. The MuCaMP guarantees to reconstruct the K-sparse signal when the sensing matrix satisfies the RIP constant ${\delta}_{N+K}<\frac{\sqrt{N}}{\sqrt{K}+3\sqrt{N}}$. In addition, we show a recovery performance both noiseless and noisy measurements.

• Food Science and Preservation
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• v.21 no.4
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• pp.473-482
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• 2014

Changes in quality of mushroom during storage are severe problem that reduce the shelf life of harvested mushrooms. This study investigates the effect of oriental melon peel extracts on maintenance of the quality of mushrooms (Agaricus bisporus). Mushrooms were dipped in solutions (distilled water, DW; 0.1% oriental melon peel extract, OMP; 0.1% ascorbic acid, AA; and OMP+AA) for 3 minutes. After the dipped mushrooms were air-dried at room temperature, they were packaged in a polypropylene (PP) films and stored at $4^{\circ}C$ and $15^{\circ}C$. The changes in the quality of mushrooms were measured in terms of their color, gas composition, firmness, and sensory evaluation during storage at $4^{\circ}C$ and $15^{\circ}C$. The antioxidant and anti-browning activities of oriental melon peel extract were measured with respect to their total polyphenol contents, total flavonoid contents, DPPH, ABTS radical scavenging, copper chelating activity and PPO inhibition activity. The samples that were dipped in all the solutions did not show significant differences in firmness and gas exchange during their storage at $4^{\circ}C$ and $15^{\circ}C$. At both storage temperatures, the OMP solution samples showed highest L value and lowest delta E value. The sensory evaluation showed that during the storage period, the overall acceptability of mushrooms treated with the OMP and OMP+AA solutions was higher than that of the untreated mushrooms. The total polyphenol and flavonoid contents of oriental melon peel extract were $4.81mg\;GAE{\cdot}g^{-1}$ and $1.18mg\;QE{\cdot}g^{-1}$, respectively. The DPPH, ABTS radical scavenging activity, copper chelating activity and PPO inhibition activity of the oriental melon peel extract lower than ascorbic acid. All these results suggest that oriental melon peel extract can be used as a natural browning inhibitor.