• Korean Journal of Microbiology
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• v.31 no.4
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• pp.267-273
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• 1993

We screened promoters inducible by superoxide radical from Escherichia coli. For this. we constructed random promoter library from E. coli MG 1655 using a promoter-probing plasmid. pJAC4. Six hundred and sixty clones in this library were classified based on their promoter strength by ampicillin gradient plate assay. Three hundred and eighty three clones with relatively weak to medium promoter strength were selected and then screened for their inducibility by superoxide radical on ampicillin gradient plate containing paraquat. Three clones (clones 5. 15 and 34) were detected to be induced by paraquat treatment and the level of induction were between 1.4 and 4 folds. Comparison of nucleotide sequences of the cloned promoter fragment with registered sequences in GENBANK and EMBL databases suggests that the cloned DNA fragments have not been yet characterized in E. coli. Transcription start sites in these clones were determined by rrimer extension and S I nuclease protection analysis. S 1 analysis of clones 5 and IS indicated that the mRNA levels were increased by paraquat treatment. Especially. clone 5 \vas found to have two transcription start sites. the upstream start site of which was selectively used by paraquat treatment. Searching for promoter clements. we found that only the downstream promoter of clone 5 has -10 and - 35 promoter elements recognized by RNA polymerase ($E\sigma^{70}$) and the others have no conserved promoter elements. This suggests that these superoxideinducible promoters may require transcription initiation protein(s) other than $E\sigma^{70}$.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.142-149
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• 2000

It had been evaluated the recombinant Circumsporozoite(CS) protein of Plasmodium viva in serologic diagnosis of vivax malaria. Western blot was done to analyse the sera of malaria patients according to the days after onset. The sera which have the terms within 15 days were shown 43.8%(14/32) of positive rates and the sera over the 16 days were shown 94.4%(17/18) of positive rates. So the total positive rate was 62%(31/50). It was 22.6%(7/31) which was shown negative response in Western blot, even though they were shown positive response in Immuuofluorescent antibody test(1FAT) using whole blood stage antigens. The positive rate of non-epidemic area(Yechon-gun, Kyongsangbuk-do) was 10.7%(3/28), and epidemic area(Kangwha-gun, Inchon-shi) was 27.6%(13/47) in Western blot analysis using recombinant CS protein. In order to applicate the recombinant CS protein in seroepidemiological survey, blood samples of 422 inhabitants were collected who lived in malaria epidemic areas, Chosm-ri, Majeong-ri, Hyangyang-ri and Noejo-n in Paju-shi, Kyonggi-do. All of them were negative in microscopic examination and two(0.5%) of them were positive in Polymerase Chain Reaction. 42(10.0%) of them were seropositive in FAT using whole blood antigens and 71(16.8%) of them were seropositive in Enzyme-linked immunosorbent assay using recombinant CS protein. It was figured out the positive rates were much higher according to the distances of villages which were closed to the demilitalized zone(DMZ) in all kind of diagnostic methods, respectively.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.102-108
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• 1994

Autonomously replicating sequence Binding Factor 1(ABF1) is a DNA-binding protein that specifically recognizes the $RTCRYN_5ACG$ at many sites in the yeast genome including the promoter element, mating-type silencer and ARS. To express the intact full-length ABF1 gene in E. coli, the ABF1 gene has been cloned into pMAL-c2 and His-61, Leu-353 and Leu-360 were substituted with other amino acid. ABF1 fusion proteins of wild type ABF1 and H61A, L353R and L360R nutants were purified by amylose resin affinity chromatography. Fusion protein of MBP and ABF1 was digested by Factor Xa and Characterized by gel retardation assay and complementation test. As aresult, we suggested that other DNA binding motif except atypical inc-finger motif is in the middle region of ABF1.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.272-279
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• 2018

This study was carried out to evaluate antimicrobial activity of isolated bacteria from various soils against two strains of Propionibacterium acnes causing acne vulgaris. Among several hundreds of bacterial strains, Paenibacillus elgii DS381, Paenibacillus elgii DS1515, Burkholderia gladioli DS518, and Streptomyces lienomycini DS620 showed high antimicrobial activities against the strains of P. acnes. All isolated bacteria showed 15.5 to 34.3 mm inhibition zone diameter in an agar well diffusion test, and especially DS620 showed the highest inhibition zone diameters (28.3~34.3 mm). Antibacterial substances were expected as lipopeptide (pelgipeptin and paenipeptin) from strains DS381 and DS1515, protease from DS518, and anthracycline antibiotic (daunomycinone) from DS620, and all these showed very low minimum inhibitory concentration [DS381 and DS1515 (0.078 mg/ml), DS518 (0.312 mg/ml), DS620 (0.000078 mg/ml)] against P. acnes. These antibacterial substances could completely kill P. acnes within 24 h in a time-kill assay. These results suggest that antibacterial substances produced by these bacteria may be utilized as useful antimicrobial agent against P. acnes and treatment medicine for acne vulgaris.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1198-1205
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• 2000

Effect of inhibitions of three kinds of Ginkgo biloba extracts(Ginkgo biloba extract, Ginkgolide A, and Ginkgolide B) on induction of reactive oxygen species and release of inflammation mediator arachidonic acid were tested. Three kinds of Ginkgo biloba extracts could not inhibit the pyrogallol auto-oxidation, but they showed the hydrogen atom donating activity in DPPH assay. When 10 ${\mu}M$ hydrogen peroxide and 400 ${\mu}g/mL$ of three kinds of Ginkgo biloba extracts were added to U937 monocytic macrophage, the induction of lipid peroxidation was not observed. The Ginkgo biloba extract showed the most powerful inhibition among the extracts. And only Ginkgolide A was good for the inhibition of the protein degradation. The release of inflammation mediator arachidonic acid was induced by adding TPA and calcimycin to U937. In this assay, even 10 ${\mu}g/mL$ of three different Ginkgo biloba extracts excellently blocked the release of arachidonic acid. Particularly, the inhibition efficiency of Ginkgolide B was about 11 times higher than that of induction, and was about 4 times higher than that of the control of noninduction. This result suggests that the release of arachidonic acid is not inhibited by the antioxidant activity of Ginkgo biloba extracts, but a pre-step of the release of arachidoinc acid is inhibited by Ginkgo biloba extracts.

• Journal of Microbiology
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• v.41 no.3
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• pp.207-211
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• 2003

Extracellular protease, from Aeromonas hydrophila Ni 39, was purified 16.7-fold to electrophoretic homogeneity with an overall yield of 19.9％, through a purification procedure of acetone precipitation, and Q Sepharose and Sephacryl S-200 chromatographies. The isoelectric point of the enzyme was 6.0 and the molecular mass, as determined by Sephacryl S-200 HR chromatography, was found to be about 102 kDa. SDS/PAGE revealed that the enzyme consisted of two subunits, with molecular masses of 65.9 kDa. Under standard assay conditions, the apparent $K_{m}$ value of the enzyme toward casein was 0.32 mg/ml. About 90％ of the proteolytic activity remained after heating at 60$^{\circ}C$ for 30 min. The highest rate of azocasein hydrolysis for the enzyme was reached at 60$^{\circ}C$, and the optimum pH of the enzyme was 9.0. The enzyme was inhibited by the serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), by about 87.9％, but not by E64, EDTA, pepstatin or 1,10-phenanthroline. The enzyme activity was inhibited slightly by Ca$\^$2＋/, Mg$\^$2＋/ and Zn/supb 2＋/ ions.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.664-678
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• 2018

This study was carried out to establish shelf life for pork cutlet of ground meat and pork lard by using various quality indicators and to understand how quality changes in these products are accelerated by temperature. The samples were selected and purchased from markets in Korea, and the chosen quality indicators were total aerobic counts and coliform group in microbiological analyses, thiobarbituric acid reactive substances assay, volatile basic nitrogen, pH, acid value, and peroxide value in physical chemical analyses, and sensory evaluation. The pork cutlet samples were stored at $-18^{\circ}C$, $-6^{\circ}C$, and $-1^{\circ}C$, whereas pork lard samples were stored at $10^{\circ}C$, $25^{\circ}C$, $35^{\circ}C$, and $45^{\circ}C$. These temperature conditions were set to real distribution conditions. The samples were then analyzed using various models including of reaction orders, arrhenius equation, and $Q_{10}$ value. The quality limits for each sample were calculated, and shelf life was estimated. The results of this experiment highlighted the importance of temperature control during the distribution process of these products and revealed that temperature is a useful parameter for the establishment of a basic database for shelf life.

• Biomolecules & Therapeutics
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• v.5 no.2
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• pp.179-186
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• 1997

The pharmacokinetics and tissue distribution of DWP20373, a novel fluoroquinolone, were examined in rats and beagle dogs after a single intravenous and oral administration. Analysis of DWP20373 in plasma, tissue, and urine was performed by both HPLC and microbiological assay. The plasma drug concentration declined biexponentially both rats and beagle dogs. In the rats, the terminal drug elimination half-life (t$_{1}$2$\beta$/) was 64 min (IV) and 57 min (PO) by bioassay, and 76 min (IV) and 77 min (PO) by HPLC. Whereas in beagle dogs, t$_{1}$2$\beta$/ was 196 min (IV) and 350 min (PO). The volume of distribution at steady-state (Vd$_{ss}$ ) was 811 ml/kg (bioassay) and 2061 ml/kg (HPLC) in rats, and 2738 ml/kg (bioassay) in beagle dogs. The total body clearance (Cl$_{t}$) of DWP20373 was 10 ml/min/kg (bioassay) and 7 ml/min/kg (HPLC) in rats, and 11 m1/min/kg (bioassay) in beagle dogs. The extent of bioavailability after oral administration was 49% (bioassay) and 67% (HPLC) in rats, and 84% (bioassay) in beagle dogs. The 24-h urinary recovery, measured by bioassay, was 2.7% after oral dosing and 5.5% after intravenous dosing in rats. Serum protein binding ratio determined at 27g/ml was 78%. This drug was also distributed in tissues in the decreasing order of liver, kidney, spleen, lung, heart, and muscle determined at 30 min after oral administration.on.

• Journal of Microbiology
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• v.40 no.4
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• pp.282-288
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• 2002

Since culture of Helicobacter pylori is relatively insensitive and cumbersome, molecular detection and typing of H. pylori isolates are gaining importance for strain differentiation. In the present study genomic DNA of 42 gastric biopsies and H. pylori isolates from corresponding patients were analyzed and compared by PCR-based RFLP assay. The 1,132-bp product representing an internal portion of ureC gene of H. pylori was amplified by PCR and digested with restriction enzymes HindⅢ, AiuⅠ and PvuⅠ. The HindⅢ, AluⅠ and PvuⅠ digestion produced 4, 7, and 2 distinguishable RFLP patterns respectively from 42-H. pylori isolates. By combining all three restriction enzyme digestions, 15 RFLP patterns were observed. However, when PCR products from 42 gastric biopsy specimens were digested by restriction enzymes HindⅢ, AluⅠ and PvuⅠ, we observed 5, 8 and 2 RFLP patterns, respectively. Patterns from 34 of 42 gastric biopsy specimens matched those of corresponding H. pylori isolates from respective patients. Patterns from the remaining eight biopsy specimens differed and appeared to represent infection with two H. pylori strains. The patterns of one strain from each of these biopsies was identical to that of the isolate from corresponding patients and the second pattern presumably represented the co-infecting strain. From the study, it appears that PCR-based RFLP analysis is a useful primary tool to detect and is distinguish H. pylori strains from gastric biopsy specimens and is superior to culture techniques in the diagnosis of infection with multiple strains of H. pylori.

• Journal of Microbiology
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• v.42 no.3
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• pp.211-215
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• 2004

Toxoplasmosis has been well known as an important human infection to consider especially in pregnant women. Although many serologic methods are available, the diagnosis of toxoplasmosis can be extremely difficult. The presence of increased levels of Toxoplasma-specific IgG antibodies indicates an infection, but it does not differentiate between a recent and past infection. The purpose of our study was to compare the performance of the ELISA T. gondii IgG/IgM test, a widely used enzyme-linked immunosorbent assay, to the ELISA IgG avidity method. One hundred and four serum samples (from 38 males and 66 females) were tested and evaluated from symptomatic patients (chorioretinitis, lymphadenopathy), and from women in their first trimester of pregnancy who were suspected of having toxoplasmosis, The high IgG avidity and ELISA IgG antibody levels were in agreement for 51 of the specimens (49.0％). Thirty-eight discrepant (borderline) results from the IgG avidity method were positive for IgM (3 specimens) and IgG (37 specimens). Interestingly, out of the eight serum samples that were positive for both IgG and IgM antibodies, two samples were low IgG avidity, and three samples were borderline. There was no statistically significant relation observed between the results of the IgG avidity method and the ELISA IgG test, and the IgG avidity method and ELISA IgM test (X$^2$=1.987; p=0.370 and X$^2$=2.152; p=0.341, respectively). The IgG avidity method was considered easy to perform and an acceptable approach for the differentiation of discrepant results (recent/chronic) and for the current detection of T. gondii antibodies. We concluded that the determination of IgG avidity is a helpful tool for the diagnosis of the ocular form of toxoplasmosis and it is a safe method for screening this disease in the first trimester of pregnancy.