• Korean Journal of Veterinary Service
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• v.19 no.3
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• pp.221-226
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• 1996

IBD's antibody level and morphological change of immune organ was examined in chicken. The results were as follows ; 1. Seventy percent at 42 day and 40% at 45 day of age chickens were reacted positively by the agar gel immunodiffusion test and 42 day and 45 day of age chickens indicated 1859, 1425 by the ELISA test, respectively. 2. In 2 and 5 day young broiler chickens, the level of maternal antibody was not proper. B/B ratio showed low level, but S/B ratio and BS were normal. 3. In layer, 100% of 8 and 86 day of age chicken and 70% at 40 day of age chicken had antibody aganist IBDV. The level of antibody was high as 2293 and 3336 in 8 and 86 day of age chicken, while was low as 1186 in 40 day of age chicken. B/B ratio showed low level and S/B ratio high level, but BS was normal.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.208-214
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• 1999

The condition for immobilization of the partially purified agarase from Bacillus cereus ASK202 and the properties of the immobilized enzyme have been investigated. Agarase was immobilized on various supports by entrapment method. The enzyme immobilized on Na-alginate bead showed the highest activity among those studied. The optimal reaction conditions of the immobilized agarase were obtained in 3%(w/v) Na-alginate for the matrix, bead diameter of 2.5mm, 1 unit of agarase solution and 1.0%(w/v) calcium chloride solution. The optimum pH and temperature of the immobilized agarase were pH and temperature of the immobilized agarase were pH 7.0 and 4$0^{\circ}C$, respectively. Km and Vmax values were 0.5mg/ml.min, respectively. The immobilized agarase conerted agar to agarobiose, and their total conversion ratio under the optimal condition was 89%.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.629-634
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• 1998

1-Deoxynojirimycin which is a potent intestinal ${\alpha}$-glucosidase inhibitor was purified from the culture broth by ion exchange chromatography, Sephadex LH20 column chromatography, TSK gel chromatography and HPLC respectively. Acute toxicity of 1-deoxynojirimycin, which was loaded through the oral as dose of 200mg/kg, was investigated in IRC mouse. None of the tested IRC mice were not dead and increase of body weight showed also the same results in comparison with control mice. The antimicrobial susceptibility of 20 pathogenic strains against 3 antidiabetic compounds (1-deoxynojirimycin, AO-128, acarbose) were obtained by agar dilution method. All of the three antidiabetic compounds has very weak antimicrobial activity (MIC>100$\mu\textrm{g}$/ml).

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.183-188
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• 1997

Antimicrobial activity of various extracts of Xanthium strumarium L. was tested against 25 strains of bacteria, yeast and fungus. The crude ethylacetate extract exhibited strong growth inhibition to the tested strains with the exception of partial Gram-negative bacteria. The property of antimicrobial compound was very stable under heat treatment at $120^{\circ}C$, but it was unstable in acid (pH 3.0) and alkali (pH 10.0) treatment. The antimicrobial compounds were purified by boiling water extraction, ethylacetate extraction, charcoal column chromatography, silica gel column chro- matography and reverse phase HPLC. The purified compound A and B were detected in a single peak (each above 98% purity) through the HPLC analysis. The compound A and B showed a strong growth inhibition against Gram-negative and positive bacteria in the agar diffusion method. When tested by the FDA method using the esterase, compound A mainly inhibited the growth of bacteria and compound B showed the growth inhibition of both bacteria and yeasts.

• Journal of Life Science
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• v.9 no.6
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• pp.653-658
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• 1999

A novel marine microorganism, Vibrio sp. YE-101, was isolated from pufferfish and investigated for its ability to synthesize tetrodotoxin (TTX). Various strains isolated from the intestine of pufferfish were grown on TCBS agar plate, and then cultured on Ocean Research Institute (ORI) medium supplemented with 3% NaCl at 23$^{\circ}C$ for 3days. The cells were harvested, disrupted, fractionated by Bio-Gel P-2 column chromatography and then TTX-producing strain, Vibrio sp. YE-101, was identified using mouse bioassay. The isolated TTX from Vibrio sp. YE-101 was also analyzed and identified by HPLC and gas chromatography-mass spectrometer (GC-MS). The mass fragmentation of trimethylsilyl derivatives of C9-base of TTX from Vibrio sp. YE-101 was interpreted and the pattern of fragmentation was same with that of authentic standard. The purfied TTX was also positive to the mouse bioassay, which clearly represents that Vibrio sp. YE-101 can synthesize TTX.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.136-139
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• 1994

Turnip mosaic virus (TuMV) was isolated from Rorippa islandica showing mild mosaic symptom in growing field of Chinese cabbage and radish. Identification of the virus was based on host range, transmission by aphids, electron micrograph, serological reaction and hybridization detection. The virus systemically infected on Chenopodium quinoa, Nicotiana clevelandii, N. glutinosa, Brassica rapa, B. campestris subsp. pekinensis and Raphanus sativus, whereas showed local infection on C. amaranticolor, Gomphrena globosa and Tetragonia tetragonoides. The virus was transmitted by aphid (Myzus persicae). The virus particle was filamentous with 720$\times$12 nm in length, and reacted positively with an antiserum of TuMV in agar gel double duffusion test. In slot-blot hybridization using the digoxigenin(DIG)-labeled RNA probe, TuMV-RNA could be detected in sap of R. islandica infected with the virus. This is the first report of a natural infection of that virus on R. islandica.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.5-10
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• 1997

Three strains of W isolated from tobacco, tomato and Pepper plants in Korea were characterized based on biological response, serological relationship, and peptide mapping of the capsid Proteins. The strains designated as TMV-common, TMV-Pepper, and TMV-tomato could be distinguishable by different visual symptoms on 3 varieties of tobacco, one variety of tomato and Pepper for each among 27 plant specieces. Serological relationships were examined by agar gel double diffusion test. Only traceable or weak reaction was observed in the incompatible antigen-antibody combinations. The Pepper strain, however, showed trace in reaction with other two antisera. Peptide maps of the capsid proteins digested by V8 protease or by trypsin were also distinguishable, suggesting differences in composition and/or sequence of the amino acids among the strains.

• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.149-153
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• 1985

Salmonella pullorum strain W was serially passaged on the brain heart infusion agar containing acrdine orange(AO) as a concentration of 100 mcg/ml. S. pullorum AO60 and S. pullorum AO150, which were subcultured 60 and 150 passages on AO media, were examined for permeability barrier function of the cell wall. AO60 and AO150 were appeared to be decreased in susceptibility against hydrophobic substances such as crystal violet, chloramphenicol and rifamycin, which might be resulted from the changes of permeability barrier function of the cell wall. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis of bacterial protein, the protein profiles of AO6O and AO150 didn't differ significantly from W, but increased amount of the band of MW 140,000-145,000 was confirmed. And [G+C] contents of DNA in AO60 and A0150 were decreased than that of W.

• Korean Journal of Veterinary Research
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• v.31 no.1
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• pp.63-69
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• 1991

The serotypes and pathogenicity of 47 isolates of Erysipelothrix rhusiopathiae from pigs with acute septicemic swine erysipelas were investigated. The serotypes were determiend by agar gel precipitation test using autoclave extracted antigens. All of the 47 isolates(42 strains from Youngnam and fi fotrains from Kyunggi province) were serotype lao Five field isolates of Erhusiopathiae serovar la were tested for pathogenicity in mice. All of 5 selected isolates were pathogenic for mice and $LD_{50}$ was $3.7{\times}10^3$ viable cells. Mice immunized subcutaneously with live vaccine did not die after challenge with virulent isolates of E rhusiopathiae.

• Korean Journal of Veterinary Service
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• v.15 no.1
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• pp.67-80
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• 1992

Avian reoviruses have been implicated in respiratory disease enteric conditions including Cloacal pasting in young thicks, pericarditis, hydropericardium, anaemia with swollen spleen and liver and petechiation of skeletal muscle and viral arthritis. This study was conducted to examine properties of reovirus field 3 strains isolated from affected broiler from several farms. An infectious agent was isolated from leg tendons and intestine of broiler with clinical tenosynovitis. The agent grew well on the chicken embryo kideny cells(CEK). One of them produced cytopathic effects(CPE) of round type and formed intranuclear inclusions, and the other was characterized by CPE of syncytical type and cytoplasmic inclusion. The properties and serological classification of field strains were examined by hemagglutin test, virus neutralization test, agar gel precipitin, electropherotype. They showed no hemagglutination reactions and not well neutralization and to possess common antigens detectable by AGP test. RNA electropherotype presented 10 segment band as the previous report. These data suggest that the field strains and standard strains (1133, 1733) may be the same group.