• Korean Journal of Veterinary Research
• /
• v.22 no.1
• /
• pp.63-66
• /
• 1982

Authors encountered a case of bovine viral leukosis in a young cattle (10 months old) with the following findings; Main clinical symptoms observed were emaciation, digestive disorder, and marked enlargement of superficial lymph nodes. Biopsied specimen of the lymph nodes revealed characteristic histological picture of bovine leukosis. A severe degree of leukocytosis (108,000/cmm) accompanied by marked lympocytosis (96%=103,680/cmm) was detected from the hematological examination of peripheral blood. Most of the lympocytes(94%=101,520) were large-sized, immature, and abnormal in their morphology. In addition, a pronounced anemia (1.78 million/cmm) without regenerative evidence of erythrocyte was noted. The serum of the patient showed positive reaction against gp antigen of bovine leukosis virus in agar-gel diffusion test.

• Korean Journal of Plant Resources
• /
• v.11 no.1
• /
• pp.106-110
• /
• 1998

The present study has been undertake to obtain the fundatmental data of optimum germination condition and to establish storage time for artificial pollinationin Codonopsis lancelata pollen. In vitro condition for germination of freshly collected and stored pollen were examined. The optium temperature for germination of fresh pollen was $25^{\circ}C$. The optium sucrose concentration in the medium ranged from 30 to 40 % and optium pH 6.0% for pollen germination. The rate of pollen germination accelerated considerably in the medium with 1% agar. 30% sucrose, and pH 6. C. lanceolata pollen remained viable for 15 days when stored at 5$^{\circ}C$ with silica gel as desiccant.

• Korean Journal of Microbiology
• /
• v.24 no.1
• /
• pp.67-72
• /
• 1986

Aromatic hydrocarbon degrading bacteria were isolated from industrial waste by using an agar plate method. The isolate DY-1 was identified as Acinetobacter sp. and found to utilize phenanthrene as tis sole carbon source. THe bacteria were proved to produce salicylic acid as an intermediate from phenanthrene through naphthalene pathway, when the products in the culture were wxamined by thin-layer chromatography. THe $Phn^+$ genes were found to be involved in two plasmids of about 4 and 40kb which were lost and not detected in the DNA samples prepared from the mitomycin C-cured cells by a gel electrophoretic analysis.

• KSBB Journal
• /
• v.32 no.2
• /
• pp.133-139
• /
• 2017

Rheum palmatum has traditionally been used as a preventive agent and medication against fever and infection. The aim of this study was to isolate and characterize an antibacterial substance from R. palmatum that is effective against bacterial vaginosis. A methanol extract from R. palmatum showed antibacterial activity against Lactobacillus vaginalis KC TC 3515, Chryseobacterium gleum KCTC 2904, and Sphingomonas paucimobilis KCTC 2834, which cause bacterial vaginosis. After extraction and pH control of the methanol extract from R. palmatum, we found that acidic and alkaline extracts did not show antibacterial activity. A neutral extract (50 mg/mL) displayed an inhibitory zone of 18 mm on a nutrient agar plate with C. gleum KCTC 2904. Fractions No. 11 and 12 among 41 fractions obtained by silica gel column chromatography produced inhibitory zones of 10 mm on nutrient agar plates with C. gleum KCTC 2904. $R_f0.15$ and $R_f0.17$ spots produced by TLC of fraction No. 11 showed antibacterial activity against C. gleum KCTC 2904. Isolation and purification of the peak at a retention time (Rt) of 9.427 min was achieved by HPLC of $R_f0.29spots$. The peak at Rt 9.427 min showed antibacterial activity against C. gleum KCTC 2904.

• Microbiology and Biotechnology Letters
• /
• v.14 no.3
• /
• pp.213-218
• /
• 1986

Hybrid plasmid pEA24, shuttle vector YRp7 carrying amylase gene of Bacillus amyloliquefaciens, was transformed to yeast Saccharomyces cerevisiae, and the expression of B. amyloliquefaciens amylase gene in yeast was investigated. The frequency of transformation to S. cerevisiae DBY747 with YRp7 was increased by treatment of 40% polyethylene glycol (MW 4, 000), PH 7.0, at 3$0^{\circ}C$, and by regeneration used 2% top agar. The amount of cellular amylase activity produced by S. cerevisiae containing pEA24 was 2% of that secreted from B. amyloliquefaciens, but in case of S. cerevisiae transformant, the amylase secreted was not detected. A comparison of genetic stability of pEA24 and YRp7 plasmids in yeast was carried out by cultivation of transformants in tryptophan-supplement-medium. The pEA24 plasmid was more unstable than YRp7 in S. cerevisiae. The size of pEA24 extracted from S. cerevisiae transformants was found to be identical with that from E. coli transformants by agarose gel electrophoresis.

• YAKHAK HOEJI
• /
• v.40 no.1
• /
• pp.25-35
• /
• 1996

Magaldrate. an antiacid was synthesized by reacting magnesium oxide, aluminum sulfate, and dried aluminum hydroxide gel. The optimum synthesis conditions based on the yield of t he product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of Magaldrate were as follows: Reaction temperature; 61~$85{\circ}C$, concentration of two reactants. Mgo and $Al(OH)_3$: 16~19.8%, molar concentration ratio of two reactants, [MgO]/[$Al(OH)_3$]; 4.2~5.0, temperature of washing water; 36~$41^{\circ}C$ and drying temperature of the product: 76~$80^{\circ}C$. Magaldrate was synthesized under the optimum synthesis conditions and identified by analyzing the chemical composition, and by differential scanning calorimetry and X-ray diffraction method. The Magaldrate sample synthesis under these conditions was used to prepare 15.6% Magaldrate original suspension which was utilized to make 13% Magaldrate suspension dispered in various concentrations of eight types of suspending agents. The acid-neutralizing capacity of 13% Magaldrate suspension dispersed in 0.25% suspending agents was examined by Rosset-Rice method. The maximum pH was reached within 1 minute in all suspension tested, and duration maintained between pH 3~5 was decreased in the order of Na alginate Na silicate(meta) Veegum HV pectin agar>Na>CMC>xanthan gum>bentonite. It was found that the hysteresis loop area was increased with temperature in the case of Riopan Plus and the addition of agar, whereas the area was decreased with temperature in the case of the addition of Na alginate and xanthan gum. 13% Magaldrate suspension tends to sediment by the addition of bentonite.

• Korean journal of applied entomology
• /
• v.15 no.3 s.28
• /
• pp.137-145
• /
• 1976

Orchids have been propagated vegetatively for a long time without adequate control measures against virus diseases in Korea. As a result, it is presumed that most of the orchid varieties in Korea may have been degenerated. Nevertheless there has been little work on the virus diseases of orchids in Korea. Therefore studies were initiated to isolate an4 characterize the orchid viruses occurring in Korea. The results obtained are summerized as follows. 1. Symptoms of virus diseases on orchid varieties can be grouped 1) mosaic, 2) necrotic streak with mosaic, 3) ring necrosis, 4) chlorotkc ring and 5) necrotic spot. 2. A total of 102 orchid plants representing 4 genera were investigated on the occurrence of Cymbidium mosaic virus and tobacco mosaic virus by serological agar-gel double diffusion test. The test revealed that approximately $45\%$ of the orchids were infected with Cymbidium mosaic virus. None of the plants were found to be infected with tobacco mosaic virus. 3. Local lesions appeared on the inoculated leaves of Chenopodium amaranticolor Cassia occidentalis and Datura stramonium 7-12 days after mechanical inoculation with Cymbidium mosaic virus. 4. Physical properties of the Cymbidium mosaic virus determined by inoculation on Chenopodium amaranticolor were as follows: Thermal inactivation Point; $75-80^{\circ}C$, dilution end Point; $10^{-5}-10^{-6}\%$ aging in vitro; 8 days. 5. Three different buffers at pH 7.0 and pH 9.0 were compared for the efficiency of agar-gel double diffusion test with Cymbidium mosaic virus. Phosphate, imidazol and tris buffer at pH 7.0 gave equally satisfactory results. 6. Electron microscopic examination of the Cymbidium mosaic virus revealed rod shaped particles measuring 460-580mu.

• Restorative Dentistry and Endodontics
• /
• v.27 no.6
• /
• pp.632-643
• /
• 2002

The purpose of this study was two-fold. First was to evaluate whether the molecular sieving model was appropriate for ionic dissociation experiment. Second was to compare the dissociation of calcium and hydroxyl ions from five types of calcium hydroxide pastes (Pure calcium hydroxide paste, DT temporary $dressing^{\circledR},{\;}Metapaste^{\circledR},{\;}Chidopex^{\circledR},{\;}Metapex^{\circledR}$) in three vehicles (aqueous, viscous and oily) and the antibacterial effect. Each calcium hydroxide pastes was placed into 0.65ml tube with cap and then 15% polyacrylamide gel was placed onto calcium hydroxide pastes. After the gel was hardened, the tubes were filled with tridistilled water (pH 7.14) and closed with cap. The tubes were stored in $37^{\circ}C$ 100% incubator The pH reading and the concentration of calcium ions were taken at 1, 4, 7. 10, and 14 days. The brain heart infusion agar plates with S. mutans and A. actinomycetemcomitans were used far antibacterial activity test. Middle of agar plate was filled with the calcium hydroxide pastes. The plates were incubated at $37^{\circ}C$ and observations were made to detect the zones of inhibition. These data were evaluated statistically by use of the analysis of variance and duncan test. The results were as follows. 1. In fresh mixing state, the pH of five types of calcium hydroxide pastes were measured between 12.5 and 12.8. 2. The pH was increased in all five types of calcium hydroxide pastes compared with control group. In 14 days, Pure calcium hydroxide paste (11.45) and DT temporary $dressing^{\circledR}$ (11.33) showed highest pH, followed by $Metapaste^{\circledR}$ (9.49), $Chidopex^{\circledR}$ (8.37) and $Metapex^{\circledR}$ (7.59) 3. Calcium was higher in all five types of calcium hydroxide pastes compared with control group. In 14 days, Pure calcium hydroxide paste (137.29 mg%) and DT temporary $dressing^{\circledR}$ (124.6 mg%) showed highest value, followed by $Metapaste^{\circledR}$ (116.74 mg%), $Chidopex^{\circledR}$ (111.84 mg%) and $Metapex^{\circledR}$ (60.22 mg%). 4. The zones of bacterial inhibition were seen around all five types of calcium hydroxide pastes. $Chidopex^{\circledR}{\;}and{\;}Metapex^{\circledR}$ groups which include iodoform were observed significantly larger zone of inhibition in A. actinomycetemcomitans compared with the other calcium hydroxide groups (p<0.05) However, $Metapex^{\circledR}$ showed the least antibacterial effect on S. mutans compared with other groups (p<0.05). The molecular sieving model was found to be acceptable in dissociation experiment of hydroxyl and calcium ions when compared with the previous tooth model study. But this model was not appropriate for the antibacterial test.

• KSBB Journal
• /
• v.14 no.1
• /
• pp.96-102
• /
• 1999

Marine bacterium Bacillus cereus ASK202 produced an extracellular agarase (E.C.3.2.1.81) which showed a high level of enzyme activity in the presence of agar and agarose. In the optimal culture conditions, the agarase production increased 7.7 folds compared with the one obtained from the basal medium. Agarase production reached upto 160 units/L after 24hr of cultivation in a modified marine medium at $25^{\circ}C$. The degree of purification increased 31.5 folds with 27.8% yield through freeze drying, DEAE Sepharose CL-6B and Superose 6HR 10/30 column chromatography. The molecular weight of the purified agarase was determined to be 90,000 daltons by gel-permeation filteration. Optimal temperature and pH for the enzyme activity were $40^{\circ}C$ and 7.8, respectively. The enzyme was stable up to $50^{\circ}C$ and at a broad pH range of 5.0-10.0. The $\beta$-agarase was activated by $Zn(NO_3)_2$, and was inhibited by $CuSO_4$ and $SnCl_2$. The Km and Vmax values of this enzyme for agarose as a substrate was $2.4mg/m\ell$ and 13.6 mg/m$\ell$, respectively.

• Korean Journal Plant Pathology
• /
• v.3 no.3
• /
• pp.223-235
• /
• 1987

Samples showing yellow mosaic symptom of Lilium spp. with necrotic fleck, stunting, malformation, and colour breaking were collected from lily-growing areas in the southern part of Korea. Two viruses were distinguished under a electron microscope and their host range, serological reaction, stability in sap, type of aphid transmission, and relations with cells and tissues were examined. Broad bean wilt virus (BBWV) was transmitted by sap-inoculation to 23 plant species in 8 families and by the aphid, Myzus persicae. This virus was inactivated after 10 min at 70C, at dilution of $10^{-3}$, and after 6 days at about 20C. Electron microscopic examination of purified preparation showed that the virus is spherical particle of 28nm in diameter. The virus reacted positively with BBWV-antiserum in agar gel diffusion test. In ultrathin sections of BBWV infected tissues, large aggregates or crystalline array of virus particles and vesicular body were found in the cytoplasm, vacuole, and nucleus of mesophyll cells. Cucumber mosaic virus (CMV) was transmitted by sap-inoculation. Electron microscopic examination of its purified preparation showed spherical particles of 30nm in diameter. The virus reacted positively with CMV-Y strain-antiserum in agar gel diffusion test. In ultrathin sections of CMV infected tissues, crystalline array of virus particles were found in the vacuole and a large number 0f virus particles were found in the cytoplasm and the plasmodesmata of mesophyll cells. When each of these viruses was retransmitted to Lilium tigrinum. L. concolor, and L. auratum, BBWV induced slight symtoms and colour breaking, but CMV induced yellowing mosaic or necrotic fleck.