• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.570-577
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• 1995

Aspergillus sp. SB-2704 was selected for its strong polygalacturonase activity among various strain of mold found in soil. It was found that production of polygalacturonase reached to maximum when the wheat bran medium containing 1% polypepton, 1% glucose, and 0.2% FeSO4 were cultured for 3 days at 35$^{\circ}C$. Polygalacturonase was purified 20.90 fold from Aspergillus SB-2704. The purification procedures include ammonium sulfate treatment, gel filtration on Sephdex G-150 and DEAE-cellulose ion exchange chromatography. Yield of the enzyme purification was 4.34%. Purified enzyme was confirmed as a single band by the polyacrylamide gel electrophoresis. When the purified enzyme was applied to SDS-polyacrylamide gel electrophoresis, the molecular weight was estimated to be 36,000. The optimum pH for the enzyme activity was 5.5 and optimum temperature was 5$0^{\circ}C$. The enzyme is stable in acidic condition. The activity of purified enzyme was inhibited by Pb2+, Hg2+ and Ba2+, whereas activated by Cu2+, Mn2+, Mg2+ and Fe2+. The activity of polygalacturonase was inhibited by the treament wit maleic anhydride, iodine, and EDTA. The result indicate the possible involvement of histidine and metal ion at active site.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.1
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• pp.44-47
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• 1998

Maximum cellulase production was sought by comparing the activities of the cellulases produced by different Trichoderma reesei strains and Aspergillus niger. Trichoderma reesei Rut-C30 showed higher cellulase activity than other Trichoderma reesei stains and Aspergillus niger that was isolated from soil. By optimizing the cultivation conditions during shake flask culture, higher cellulase production could be achieved. The FP(filter paper) activity of 3.7U/ml and CMCase (Carboxymethylcellulase) activity of 60U/ml were obtained from shake flask culture. When it was grown in 2.5L fermentor, where pH and DO levels are controlled, the enzyme activities were 133.35U/ml (CMCase) and 11.67U/ml(FP), respectively. Ammonium sulfate precipitation method was used to recover enzymes from fermentation broth. The dried cellulase powder showed 3074.9U/g of CMCase activity and 166.7U/g of FP activity with 83.5% CMCase recovery.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.1
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• pp.100-107
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• 2008

The objective of this study was to quantitatively estimate PM-10 source contribution in Gumi City, Korea. Ambient PM-10 samples were collected by a high volume air sampler, which operated for 84 different days with a 24-h sampling basis, from June 14,2001 though May 19, 2003. The filter samples were analyzed for determining 13 inorganic elements, 3 anions, and a total carbon. The study has intensively applied a receptor model, the PMF (Positive Matrix Factorization) model. The results from PMF modeling indicated that a total of seven sources were independently identified and each source was contributed to the ambient Gumi City from secondary sulfate (34%), motor vehicle (26%), soil relation (5%), field burning (3%), industrial relation (3%), secondary nitrate (22%), and incinration (7%) in terms of PM-10 mass, respectively.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.344-351
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• 1990

An alkalophilic microoganism producing a detergent-resistant alkaline protease was isolated from soil and identified as Baeiltus sp. The alkaline protease has been partially purified by ammonium sulfate fractionation, DEAE-Cellulose, CM-Cellulose and Sephdex G-100 column chromatography. The purified alkaline protease was highly active at pH 12-13 toward casein and stable at pH values from 6 to ll. The optimum temperature for the enzyme reaction was $55^{\circ}C$. The enzyme was completely inactivated by diisopropyl fluorophosphate (DFP) indicating that the enzyme was serine protease, but considerabiy stable in the presence of surface active agents.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.271-276
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• 1994

The strain S4-14 which produced alkaline lipase and had resistance against linear alkylbenzene sulfonate was isolated from soil or water samples. The isolated strain S4-14 was identified a species belong to Pseudomonas. Alkalin lipase secreted by Pseudomonas sp. S4-14 was purified by ammonium sulfate precipitation procedure follwed by DEAE-Cellulose, DEAE-Sepharose and gel filtration chromatohraphies with 995.15 U/mg protein and 16.1% yield. The molecular weight of the enzyme was estimated to be 65,000 dalton by SDS-PAGE. The optimum pH and temperature of the purified enzyme was 10.5 and 45$\circ $C, respectively. The emzyme was stable at 45$\circ $C for 1 hr and in a pH range from 8.0 to 12.0 for 24 hr at 4$\circ $C. The activity of lipase was enhanced by Ca$^{2+}$ while inhibited strongly by Pb$^{2+}$, Zn$^{2+}$ or Fe$^{3+}$. The activity of lipase was inactivated about 50~60% in the presence of 50 mg/l linear alkylbenzene sulfonate, $\alpha $-olefin sulfonate, alcohol ethoxylate or perborate.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.121-126
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• 1997

A bacterial strain LC-413, producing an extracellular inulin fructotransferase (depolymerizing) which converts inulin into di-D-fructofuranose dianhydride (DFAIII), was isolated from soil. Inulin fructotransferase from the isolate identified as a strain Flabobacterium sp. was purified from the culture broth by ammonium sulfate precipitation, followed by column chromatograpies on DEAE-Toyopearl 650 M and phenyl-Toyopearl 650 M. The purified enzyme gave a single band on an electrophoretic disc-gel. The molecular weight of the enzyme was estimated to be 44, 000 Da by SDS-polyacrylamide gel electrophoresis, and 45, 000 Da by gel filtration, suggesting the monomeric state of the enzyme. The isoelectric point of the enzyme was about pH 4.5. The optimal pH and temperature for the enzyme reaction were 6.0 and $50^{\circ}C$, respectively. The purified enzyme digested inulin into di-D-fructofuranose-l, 2': 2, 3'-dianhydride, confirming the enzyme was an inulin fructotransferase (inulinase II).

• Journal of Microbiology and Biotechnology
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• v.7 no.1
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• pp.37-42
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• 1997

A bacterial strain L1 producing a thermostable esterase was isolated from soil taken near a hot spring and identified as Bacillus stearothermophilus by its microbiological properties. The isolated thermostable esterase was purified by ammonium sulfate fractionation, ion .exchange and hydrophobic interaction chromatographies. The molecular weight of the purified enzyme was estimated to be 50,000 by SDS-PAGE. Its optimum temperature and pH for hydrolytic activity against PNP caprylate were $85^{\circ}C$ and 9.0, respectively. The purified enzyme was stable up to $70^{\circ}C$ and at a broad pH range of 4.0-11.5 in the presence of bovine serum albumin. The enzyme was inhibited by phenylmethylsulfonyl fluoride and diethyl p-nitrophenyl phosphate, indicating the enzyme is a serine esterase. The enzyme obeyed Michaelis-Menten kinetics in the hydrolysis of PNPEs and had maximum activity for PNP caproate ($C_6$) among PNPEs ($C_2-C_12$) tested.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.339-345
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• 1987

A bacterium K-4-3, producing $\beta$-glucan hydrolyzing enzyme, was isolated from soil and identified to be Bacillus subtilis by its morpholohical and physiological characteristics. $\beta$-glucan was coloured using cibacron blue 3G-A and cross linded by the addition of 1, 4-butanedioldiglycidyl ether. This substrate was used for the isolation of $\beta$-glucanase producing microorganism. The $\beta$-glucan hydrolyzing enzyme actibity from isolated K-4-3 strain was also measured using the modified substrate. Bacillus subtilis K-4-3 produced the highest extracellular $\beta$-glucan hydrolyzing activity in the basal medium containing $\beta$-glucan as a carbon source, peptone and tryptone as a nitrogen source, and magnesium sulfate as an inorganic salt. The optimum temperature and initial pH for $\beta$-glucanase production by Bacillus subtilis K-4-3 were $37^{\circ}C$ and pH6. The highest enzyme activity was obtained at the culture age of 54 hrs with rotary shaking at $37^{\circ}C$. The crude enzyme showed the highest activity at pH 7.5-8.0 and $65^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.131-155
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• 1983

Though it has been widely known the nitrogen effects are influenced by soils, varieties, and mineral nutrients in the rice culture, few analyses in relation to the factors increasing nitrogen effect have been studied in Korea. The effects of potassium and silica on the factors increasing nitrogen effects in paddy soils were investigated in accordance with soil improvement practices and nitrogen application methods for the cultivated varieties. The results obtained are as follows. 1. For 413 paddy fields, the yield from soils without nitrogen application ranged from 200 to 850kg/10a and that from nitrogen application did 350 to 1,051kg/10a. The yield increament by nitrogen application varied 50 to 650kg/10a depending on soils. 2. Soil chemical characteristics for high yield were different between with nitrogen and without nitrogen application. In the without nitrogen application, however, contents of organic matter, phosphorous, potassium and calcium of high yield soils were lower than those of low yield, while the available silica content was higher in the former. 3. The yield increased with nitrogen application up to 22.4kg/10a and thereafter it decreased. These phenomena were supposed to be not be decrease of nitrogen uptake but by lowered silica uptake. 4. Clay soil incorporation, deep plough, and inorganic constituents control such as Ca, Mg, and $Sio_2$ were effective as soil improvement praitices. It was appeared that increases of silica content and Ca/Mg ratio were important to increase nitrogen effects. 5. For the correlation between yield and yield components, it was high between yield and panicle in low nitrogen level and so was it between grain yield and ripening rate in high nitrogen. 6. In the urea and super granule urea application plot, recovery rate of nitrogen by plant and soil was high and yield was remarkable high. 7. Regardless of fertilizer types such as ammonium sulfate and urea, the residual nitrogen was about 4kg/10a in both plots of 5.8 and 11.6kg/10a. N applied. 8. The potassium application to soil enhanced the nitrogen efficiency. It was more effective in low potassium soil. 9. Optimum pH value for gel formation in the 4% sodium silicate solution was approximately 6.6. 10. It was suggested that silica could affect to rice plant growth as the inorganic and organic chemical components.