• Journal of Microbiology and Biotechnology
• /
• v.30 no.3
• /
• pp.368-377
• /
• 2020

Enterotoxigenic Bacteroides fragilis (ETBF) is the main pathogen causing severe inflammatory diseases and colorectal cancer. Its biofilm plays a key role in the development of colorectal cancer. The objective of this study was to determine the antagonistic effects of cell-free supernatants (CFS) derived from Clostridium butyricum against the growth and biofilm of ETBF. Our data showed that C. butyricum CFS inhibited the growth of B. fragilis in planktonic culture. In addition, C. butyricum CFS exhibited an antibiofilm effect by inhibiting biofilm development, disassembling preformed biofilms and reducing the metabolic activity of cells in biofilms. Using confocal laser scanning microscopy, we found that C. butyricum CFS significantly suppressed the proteins and extracellular nucleic acids among the basic biofilm components. Furthermore, C. butyricum CFS significantly downregulated the expression of virulence- and efflux pump-related genes including ompA and bmeB3 in B. fragilis. Our findings suggest that C. butyricum can be used as biotherapeutic agent by inhibiting the growth and biofilm of ETBF.

• Journal of Microbiology
• /
• v.40 no.1
• /
• pp.63-69
• /
• 2002

A total of twenty-five norfloxacin resistant Escherichia coli were isolated from Joongrang-chun stream, a branch of the Han River in Seoul, Korea from May to July in 2000 and their norfloxacin resistance mechanism was characterized for target site mutation, permeability, and efflux pump. Fourteen iso- lates contained the same three mutations, Ser83→Leu and Asp87→Asn in GyrA and Ser90→ lle in ParC. Six isolates had Ser83→Leu and Asp87→Tyr in GyrA and Ser87→lle in ParC while one isolate had Ser83→Leu and Va1103→Ala in GyrA and Ser80→lle in ParC. Two isolates had mutation(s) in GyrA without any mutation in ParC. Two isolates had Ser80→Arg in ParC instead of the commonly found Ser80→lle. Every norfloxacin resistant isolate had an efflux system but the correlation between the efflux activity and MIC was not observed. The amount of OmpF for norfloxacin permeability decreased in resistant isolates compared to the susceptible strains. When amplified polymorphic DNA (RAPD) and pulse field gel electrophoresis (PFGE) were performed, these isolates showed no similarity to each other or clinical isolates.

• Korean Journal of Environmental Biology
• /
• v.19 no.4
• /
• pp.302-312
• /
• 2001

Immunoglobulin G was purified by 40% $(NH_4)_2SO_4$ precipitation, DEAE-Sephadex, Sephadex G-150 column chromatographies from rabbit antiserum against V. vulnificus ATCC 27562 O antigen and used for immunological test for V. vulnificus isolates. The profiles of cell lysate total protein and outer membrane protein from the isolates were analyzed by SDS-PAGE and densitometry. The overall profiles in all isolates were similar. Distict protein band was observed in comparison with V. parahaemolyticus. Western Blotting with rabbit Immunoglobulin G against cell lysates and OMP of V. vulnificus isolates showed a strong antigenic response to antigen 66, 60, 54, 48, 33 and 26 kDa which were common to all strains examined. The 26 kDa antigen showed V. vulnificus specific antigen in comparison with Vibrio parahaemolyticus. A sandwich enzyme-linked immunosorbent assay was developed by using rat anti-V. vulnificus ATCC 27562 polyclonal antibodies as capture antibody, a purified rabbit IgG antibody as detector antibody, and goat anti-rabbit IgG-alkaline phosphatase conjugate as developer antibody. When four V. vulnificus isolates were tested, the reactivity showed from 50 to 70% by sandwich ELISA.

• The Plant Pathology Journal
• /
• v.32 no.3
• /
• pp.266-272
• /
• 2016

A bacterial tyrosine sulfotransferase, RaxST, is required for activation of rice XA21-mediated immunity, and it catalyzes sulfation of tyrosine residues of Omp1X and RaxX in Xanthomonas oryzae pv. oryzae, a causal agent of bacterial blight in rice. Although RaxST is biochemically well-characterized, biological functions of tyrosine sulfation have not been fully elucidated. We compared protein expression patterns between the wildtype and a raxST knockout mutant using shotgun proteomic analysis. Forty nine proteins displayed a more than 1.5-fold difference in their expression between the wildtype and the mutant strains. Clusters of orthologous groups analysis revealed that proteins involved in cell motility were most abundant, and phenotypic observation also showed that the twitching motility of the mutant was dramatically changed. These results indicate that tyrosine sulfation by RaxST is essential for Xoo movement, and they provide new insights into the biological roles of RaxST in cellular processes.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.4
• /
• pp.594-599
• /
• 2007

It is well known that the Escherichia coli inner membrane-bound protease DegS is a periplasmic stress sensor for unfolded outer membrane proteins (OMPs). Previous studies have also shown that the outer membrane protease OmpT activates plasminogen in vitro and this may be exploited by bacteria in the course of pathogenesis. However, there has been no research on the plasminogen activation ability of the important periplasmic protein DegS. Accordingly, in this study, the whole-length and truncated degS genes were separately overexpressed in Escherichia coli, the recombinant proteins purified by affinity chromatography, and their plasminogen activator role tested in vitro. The results suggested that the whole-length DegS was able to activate plasminogen on a plasma plate. The truncated form of DegS (residues 80-345), designated ${\Delta}DegS$, also acted as a plasminogen activator, as confirmed by different assays. The serine protease property of ${\Delta}DegS$ was verified based on the complete inhibition of its enzyme activity by PMSF (phenylmethanesulfonyl fluoride). Therefore, the present results indicate that DegS is a plasminogen activator in vitro.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.1
• /
• pp.84-89
• /
• 2001

This paper deals with multiresolution analysis of wavelet transform for partial discharge(PD), composite discharge(corona + surlace discharge). Multiresolution analysis was used for performing discrete wavelet transform PD signals was decomposed into "approximation" and "detail" cOmpJnents until 4 levels by using discrete wavelet analysis. In this paper, daubechies family is adopted for the research of the characteristics of PD signals. 1be results show that in corona discharge the segment 7, 8, 9, 10, 1] values of defined variable is increased with discharge process, so phase distribution is characterized by 210~330 ranges. In case surface discharge in expoxy insulator inserted, defined variable values is fairly symmetric chscharge pattern because coupled both corona and dielectric oounded discharges. We can confimJly discriminate the type of PD source.

• Textile Coloration and Finishing
• /
• v.19 no.5
• /
• pp.1-7
• /
• 2007

A new UV-curable coating was carried out to impart the flame-retardant property to cotton fabric using Bis[2-(methacryloyloxy)ehtyl]phosphate(DMEP) and 2-hydroxy-2-methyl-1-phenyl-propan-l-one(HMPP) as a UV-curable monomer and a photoinitiator, respectively. The cotton fabrics were applied with various amounts of DMEP and HMPP via padding and UV irradiation, and the optimal concentrations of DMEP and HMPP in the formulation were 40%(w/w) and 7%omp respectively. A limiteed oxygen index(LOI) up to 28.9 was obtained for the UV-cured fabric, which may occur through a condensed phase mechanism as verified by the increased residue number with increased application level. The characterization of the UV-cured coating was made by IR analysis, thermo-gravimetric analysis, LOI test, and scanning electron microscopy.

• International conference on construction engineering and project management
• /
• 2005.10a
• /
• pp.662-666
• /
• 2005

Using data gathered from expert opinion of plant and equipment professionals; this paper presents the key variables that may constitute a maintenance proficient plant operator. The Multivariate Discriminant Analysis (MDA) was applied to generate data and was tested for sensitivity analysis. Results showed that the MDA model was able to classify plant operators' proficiency at 94.10 percent accuracy and determined nine (9) key variables of a maintenance proficient plant operator. The key variables included: i) number of years of experience as equipment operator (PQ1); ii) eye-hand coordination (PQ9); iii) eye-hand-foot coordination (PQ10); iv) planning skills (TE16); v) pay/wage (MQ1); vi) work satisfaction (MQ4); vii) operator responsibilities as defined by management (MF1); viii) clear management policies (MF4); and ix) management pay scheme (MF5). The classification procedure of nine variables formed the general model with the equation viz: OMP (general) = 0.516PQ1 + 0.309PQ9 + 0.557PQ10 + 0.831TE16 + 0.8MQ1 + 0.0216MQ4 + 0.136MF1 + 0.28MF4 + 0.332MF5 - 4.387

• Journal of KIISE:Information Networking
• /
• v.31 no.4
• /
• pp.384-392
• /
• 2004

Mobile contents service providers have some difficulties to timely and proper service deployment due to rapid development cycle of diverse portable devices with different capabilities. A way to resolve the problem is to introduce a mobile contents service paltform that can adapt original mobile contents to diverse devices dynamically and automatically. In this paper, we propose a mobile contents service platform based on active network mechanisms, called Mobile Content Adaptation Network(MobiCAN). The MobiCAN node provides effective service deployment, execution, and maintenance features and accommodates service layering and service customization capabilities for easy deployment. The basic functional units of the MobiCAN node are micro services with well-defined service interfaces and service layering features. For reliable services among the MobiCAN nodes, we design new distributed and robust Overlay Management Protocols(OMPs). As an example of practical MobiCAN applications, we finally describe Dynamic Contents Customization Proxy(DCCP) service.

• Magazine of the Korea Concrete Institute
• /
• v.7 no.3
• /
• pp.156-163
• /
• 1995

In the previous study, styrene mdleic dnhydride copolymer(SMA) as synthesized flom styrene and rnale~c dnhydr~de and further redcted with sulfuric acid to obtam water soluble SMA. In thls study, the flow dnd strcngth tests of cement mortar rmxed wth copolymers wele carried out to evaluate the capability of copolymers as high range water reducer for the con crete. It was found from flow exper~ment that the fluidity of cenient mortar rmxed wth sulfonated SMA(SSMAj was larger thdn that mxed ulth amnophenol substituted SSMA (SmSMAj. The decreasing rate of the flow of cement mortar rmxed ulth SSMA and SmSMA was significantly lower than that mixed ulth naphthalene condensate(NSC) The compressslve strength of the hardened cement mortars containing 0.5% copolymers after 28 dys curing was exarmned. 'The compressive strength of hdrdened cement mortar containing SSMA and SmSMA was mcreased up to 31% and 13%, respectively, when omp pared to the plain. As the results, the copolyniers(SSMA and SrnSMA) used in thls study are greatly expected as a good high range water reducers for the concrete.