• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.414-418
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• 2011

BACKGROUND: Plastic mulches widely used in raised-bed culture mainly to conserve water, control weeds and raise soil temperature. The most widely used plastic mulch colour is black. Reflective red and far-red light can affect on growth and yield of various vegetable crops. Objectives of this study were to investigate the characteristics of reflective light of black and red plastic mulches, and to evaluate the reflective red and far-red light on the quality characteristics and yield of the Oriental melon (Cucumis. Melo L.) and tomato (Lycopersicon esculentum L.). METHODS AND RESULTS: Oriental melon and tomato were cultivated over the reflective red and black plastic mulches in plastic house. Reflected red and far-red light over the red plastic mulch were 2.6 times higher than those of black plastic mulch. Red to F-Red ratio of black plastic mulch, red plastic mulch and sunlight were 1.14, 0.93 and 1.16 respectively. Intensity of reflected red and far-red light over red plastic mulch were highest at surface height of 30 cm. The higher the height of the surface decrease the intensity of far-red light. Accordingly, Red to F-Red ratio were increased. Reflective red plastic mulch increased the weight of fruit and content of sugar in Oriental melon and tomato. CONCLUSION(s): Yield of Oriental melon over reflective red plastic mulch was higher than that of black plastic mulch. These results suggested that reflected red and far-red light over the red plastic mulch affected allocation of photosynthate in growing Oriental melon.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.349-354
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• 1996

The Polyvinyl alcohol(PVA) oxidase involved in PVA degradation by microorganism has been purified to homogeneity from culture broth of Xanthomonas campestris J2Y grown in a minimal medium containing PVA as a sole carbon source. The enzyme was purified by DEAE-cellulose chromatograpy and Sephadex G-150 gel filtration. The purified PVA oxidase was electrophoretically homogeneous both in the absence and presence of SDS. The molecular weight of the enzyme was estimated to be about 55,000 daltons by SDS-polyacrylamide gel electrophoresis and Sephadex G-150 gel filtration. The native enzyme existed as a monomer. The optimal pH and temperature was shown to be pH 7 and $37^{\circ}C$ respectively. The activity of enzyme was stable below $55^{\circ}C$ and between pH range of $5{\sim}11$. The enzyme activity was significantly inhibited by metal compounds such as $Ag^{2+},\;Hg^{2+}$. While, metal ions such as $Mn^{2+},\;and\;Cu^{2+}$ stimulated the reaction. Km value of the enzyme for PVA was $7.04{\times}10^{-2}mmol/{\ell}$.

• The Korean Journal of Mycology
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• v.42 no.4
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• pp.328-332
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• 2014

For mass production of entomopathogenic fungus Beauveria bassiana 149, isolated from moth larva, by two-phase fermentation, we performed selection of carbon and nitrogen sources for liquid culture and examined solid fermentation on carrier, ingredient, temperature, and water content. Spore production with rice powder, corn powder, and starch from sweet potato was higher than that of sucrose and dissolvable starch for liquid fermentation as first-phase fermentation. As a nitrogen source, addition of peptone and yeast powder showed higher spore production than $NaNO_3$, fish powder, and soybean powder. The isolate produced more conidia in sawdust + wheat bran + corn powder, sawdust + wheat bran and rice shell + wheat bran as carrier and ingredient than vermiculite as carrier. Conidia production of B. bassiana 149 in solid-phase fermentation was twice higher at 30 than 20. Conidia yield was higher at 60% and 70% water content ($26.9{\times}10^8$ and $38.6{\times}10^8conidia/g$) than 40% and 50% ($13.9{times}10^8 $and $11.6{\times}10^8conidia/g$), respectively.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.1-6
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• 1993

The activity change of mulberry seeds protease was compared during germination for 5 days at 28$^{\circ}C$ in the dark place after daily hormone injection of different concentration. The protease from germinated mulberry seeds for 4 days was partially purified and the enzyme characteristics was investigated. The protease activity of mulberry seeds treated by hormone was highest with 10 $\mu$m GA3 followed by 10 $\mu$M zeatin and 10 $\mu$M kinetin. The protease activity of mulberry seeds was increased by 14% with 10ml agar culture that control at 4th day of germination. The protease from mulberry seeds was purified 313 fold by DEAE-Toyo-pearl 650M, Butyl-Toyopearl, Hydrozylapatite and Toyopearl HW 55M. After purification, the specific activity of the enzyme was 175 units/mg. Optimum pH and temperature of protease from mulberry seeds was 5.0 and 37$^{\circ}C$, respectively. The protease was stable below 37$^{\circ}C$ and the enzyme activity was decreased by 50%, when incubated at 52$^{\circ}C$ for 10minutes. The protease activity of mulberry seeds was inhibited by metal ions such as mercury, iron, zinc, copper, but activited by magnesium, choromium, aluminium ions. The Km value of the protease was 0.89mM with azocasein as a subscribe.

• Korean Journal of Microbiology
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• v.9 no.3
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• pp.130-138
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• 1971

In order to investigate the production of aflatoxin in various conditions such as pH, moisture and temperature, 27 smaples were inoculated with Aspergillus flavus, and in addition 3 smaples were inoculated with the mixture of Aspergillus flavus and Bacillus subtilis and cultured under the conditions such as 20.deg.C and 30% moisture contents. The following results were obtained : 1) Aflatoxin production was the highest at pH 5.0 and relatively high at pH 7.0. Its production was decreased significantly when pH reached 9.0. 2) The yield of aflatoxin was shown comparatively high level at 30% moisture contens. The higher moisture contents was, the lower aflatoxin production was. 3) The highest level of aflatoxin production was at 20.deg,C, and comparatively high level was at 30.deg.C. However, its production was fairly low at 40.deg.C. 4) The highest crude aflatoxin production was 5,093ppm (B$_{1}$, 1.912ppm ; B$_{2}$, and the lowest one 2.197 ppm (B$_{1}$, 0.793 ppm : B$_{2}$, 0.185 ppm : G$_{1}$ ,0.102 ppm G$_{2}$, 0.381ppm) at 63% moisture, pH 9.0 and 40.deg.C. 5) When Aspergillus flavus and Bacillus subilis were cultured together under the conditions such as 20.deg.C and 30% moisture, aflatoxin production was decreased by 27% comparing with the culture of Aspergillus flavus alone.

• Journal of Life Science
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• v.23 no.2
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• pp.259-266
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• 2013

To isolate the fibrinolytic enzyme, 268 strains from 21 samples were morphologically isolated from Cheonggukjang collected from Korea and Japan. Among the 268 strains, protease-producing bacteria were isolated in nutrient agar medium including 1% skimmed milk. As a result of this, 22 strains were isolated. Apiweb site was used to identify these strains based on their biochemical properties. In addition, 16S rRNA sequencing was performed to identify the strain. Most of the identified strains were Bacillus subtilis and B. amyloliquefaciens. Fibrinolytic enzyme activity was measured with the fibrin plate method. Five strains were finally selected: A2-14, A2-20, C1-05, C1-09, and F2-01. Of those five strains, the A2-20 strain, which is close to B. amyloliquefaciens, showed the strongest fibrinolytic activity. The fibrinolytic enzyme produced by the A2-20 strain was partially purified from culture supernatant by gel filtration and ion exchange chromatography. The optimal pH and temperature values of the partially purified enzyme were 7.0 and $35^{\circ}C$, respectively. Purified protein analysis was carried out with SDS-PAGE and zymography. A genetic analysis was also conducted by PCR based on the consensus sequence of fibrinolytic enzyme. Corresponding genes with a partial sequence of the A2-20 strain were identified.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.233-240
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• 1987

The amniotic fluid provides a medium in which the fetus can readily move, cushions him against possible injury and helps him maintain an even temperature. Besides above mentioned functions, investigators reported that human amniotic fluid contains host-resistance factors which prevent bacteria from producing infectious disease and this activity shows difference among human racial groups or bacterial genera, species and strains. 40 amniotic fluid specimens from Korean women in their second and third trimesters of pregnancy were examined for inhibiting the growth of Escherichia coli. And various factors which might affect bacterial growth inhibiting activity such as pH, initial inoculum size, concentration of amniotic fluid, and heat resistance, were also tested using a strongly inhibitory amniotic fluid specimen. Finally plate diffusion tests were carried out using other strongly inhibitory amniotic fluid. The following results were obtained: 1. Of the 40 fluid samples examined, 18 specimens(45%) had inhibitory activity and samples from women in their second trimester of pregnanancy showed non-inhibitory activity(2 specimens). 2. The pH of the fluids varied between 7.43 and 8.33. There was no correlation between pH and inhibitory activity. 3. No. 19 amniotic fluid showed bacteriostatic activity after 24 hours incubation when an inoculum of $10^2$ organisms per milliliter was used, but non-inhibitory with an inoculum of $10^3$ and $10^4$ bacteria per milliliter. 4. The content of amniotic fluid in culture media influenced E. coli growth. At 90 percent, E. coli was inhibited growth but at 10 percent and 50 percent. 5. Inhibitory activity of No. 19 amniotic fluid was retained after heating to $50^{\circ}C$ for 30 minutes or 100^{\circ}C$ for 30 minutes. 6. Plate diffusion tests with No. 27 amniotic fluid showed that 0.7ml amniotic fluid gave clear zone of growth inhibition around the central well but 0.2ml and 0.1ml amniotic fluids were not.

• Journal of fish pathology
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• v.23 no.3
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• pp.335-342
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• 2010

In 2008, mass mortality was observed in paradise fish Macropodus opercularis which was imported from Indonesia. PCR of these fish found positive for megalocytivirus and Mycobacterium sp., while an unidentified virus was culture-isolated using CHSE-214 cells. In the present study, we investigated characterization of the unidentified virus and its pathogenicity to determine whether the virus was the causative agent of the mass mortality of paradise fish. The unidentified virus induced cytopathic effect (CPE) with syncytia in CHSE-214 and other fish cells, BF-2, GF, SSN-1, FSP and FFN. The virus was resistant against treatments with IUdR, chloroform, acidity at pH 3, basicity at pH 11 and high temperature at $56^{\circ}C$ for 3h. By electron microscopy, the viral particles were spherical having a double capsid structure with approximately 65 nm in external diameter. Viral genome was composed of at least 10-segmented RNA with sizes ranging from 0.7 kb to 3.6 kb. Based on these characters, this virus can be classified into family Reoviridae. This reovirus did not cause any mortality in an artificial experiment conducted by injecting the virus to paradise fish. This indicates that the reovirus is not only responsible for the mass mortality of paradise fish in 2008.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.501-508
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• 2007

In order to develop a new starter for fermented milk, Lactobacillus plantarum M23 was isolated from raw milk and investigated for physiological characteristics. It showed good tyrosinase inhibitory activity compared with commercial lactic acid bacteria. The optimum growth temperature of Lactobacillus plantarum M23 was $40^{\circ}C$ and cultures took 17 hr to reach pH 4.3. Lactobacillus plantarum M23 showed more sensitivity to Penicillin-G, Oxacillin, Novobiocin, Chloramphenicol in a comparison of 12 different antibiotics, and showed most resistance to Vancomycin. It showed higher leucine arylamidase and ${\beta}-galactosidase$ activities compared to 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hours. It showed high resistance to Escherichia coli, Salmonella typhimurium and Staphylococcus aureus with rates of 77.8%, 86.5% and 83.8%, respectively. Based on these and previous results, Lactobacillus plantarum M23 could be an excellent starter culture for fermented milk with high resistance to melanin.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.661-665
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• 2002

In order to develop ginseng tea powder with spore forming lactic acid bacteria Lactobacillus sporogenes was used. In the jar fermentor experiment under optimal culture conditions, the number of spore of L. sporogenes reached about $20{\times}10^8\;CFU/mL$ and sporulation rate was 97%. Granulated ginseng tea was made from glucose 7 kg, lactose 2 kg, ginseng extract 1 kg and spores 5 g $(5200{\times}10^8\;CFU/g)$. In the treatment of artificial gastric juice (pH 3.0) for 4 h and artificial bile for 8 h, the survival rate of spores in the granulated ginseng tea was 55.4% and 90.0% respectively. The spores survived 77.6% after incubation for 20 min in boiled water. Its storage stability was about 75% for 12 months at room temperature.