• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.50-56
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• 2002

The $\beta$-galactosidase was purified from the internal organs of edible snail by fractionation with ammonium sulfate, ion exchange chromatography on DEAE-Sephadex, Mono Q HR 5/5 and gel filtration on Sephacryl S-200. Superose 12 HR 10/30 chromatography. The specific activity of the purified $\beta$-galactosidase was 18.8 units/mg protein with 31.3 purification fold from crude extract. The $\beta$-galactosidase had native molecular weight of 144,000 dalton and was composed of two subunits of 72,000 dalton. The isoelectric point of the enzyme was determined 4.1. This enzyme was the most active at pH 3.0 and 6$0^{\circ}C$, and was stable in the pH range 2.0~8.0 and below 5$0^{\circ}C$. The enzyme was inhibited by metal ions and sugars such as fructose, glucose, galactose, maltose and xylose.

• Analytical Science and Technology
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• v.6 no.3
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• pp.307-311
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• 1993

Ionophore, which contains 5-membered heterocyclic compound, was prepared. $Mg^{2+}$ was determined by salting-out technique using ionophore as a chelating reagent. After $Mg^{2+}$ was extracted into the acetonitrile layer as a Mg-$(Ionophore)_2$ complex from acetate buffered aqueous solution by salting-out extraction technique, absorbance of complex was recorded by atomic absorption spectrophotometry. Optimum pH was between 2.5 and 5.0 for extraction and 1:2([$Mg^{2+}$]/[ionophore]) complex were formed. The range of detection was 0.24ppm~2.4ppm and $Ca^{2+}$ and EDTA were interfered in the determination of $Mg^{2+}$.

• Microbiology and Biotechnology Letters
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• v.29 no.4
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• pp.221-226
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• 2001

Streptomyces themocyaneovio-laceus producing the thermostable xylanase was used for the production of xylooligosaccharides from xylan. The optimal conditions for the xylanase production were investigated in jar fermentor, which operated at 2 vvm aera-tion and 400 rpm agitation speed at $50^{\circ}C$ for 24 h. The optimal reaction condtion for the production of xylooli-gosaccharides with xylanases which were prepared by the percipitation with ammonium sulfate were obtained by the reaction at $60^{\circ}C$ for 12 h in the mixture composed of 10% birchwood xylan in 50 mM sodium phosphate buffer (pH 6.0)and 10 unit/ml of xylanase. In this optimal condition for the xylooligosaccharides production the mixture of xylooligosaccharides (58.8 g/I) which were composed of 20.1 g/I of xyobiose, 8.9 g/I of xylotriose 4.5 g/I of xylotetraose 16.2g/I of xylopentaose and 9.1 g/I xylohexaose and 5.0 g/I of xylose was produced from 100 g/I of birchwood xylan by the xylanases of S thermocyaneoviolaceus .

• Applied Biological Chemistry
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• v.33 no.1
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• pp.79-86
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• 1990

Cyclodextrin hydrolase from Bacillus stearothermophilus KFCC 21203 was purified and the properties of the purified enzyme were investigated. The enzyme was purified 15 folds with 77 % recovery by ammonium sulfate fractionation, DEAE-cellulose chromatography, and Ultro AcA 34 gel filtration. The specific activity and the molecular weight of the enzyme were 1.30 units/mg protein and about 29,500, respectively, The maximum activity of the enzyme was shown at $55^{\circ}C$ and pH 5.5. However, stable temperature and pH were $40^{\circ}C$ and $5.0{\sim}8.0$, respectively. The Km value for ${\gamma}-cyclodextrin$ was $3.78{\times}10^{-3}$ M. The degradation activity of the enzyme was selectively high for ${\gamma}-cyclodextrin$, and very low for ${\beta}-cyclodextrin$, but not for ${\alpha}-cyclodextrin$. The decomposed products of ${\gamma}-cyclodextrin$ were mainly glucose and maltose, and a little mlatotriose. The activity of the enzyme was very high for amylose, potato starch, corn starch, amylopectin and maltooligomer, and relatively high for glycogen and dextrin. The decomposed products of them were mainly glucose and maltose.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.47-52
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• 1983

The extracellular inulase produced by Aspergillus sp. C-58 was isolated by pH and charcoal treatment, precipitation with ammonium sulfate from the crude extract, and separated into 3 fractions (P-I, II, III) by DEAE-cellulose column chromatography in the ratio of 31.1:1.7:1 with respect to the activity. The ratio of inulase activity to sucrase activity of P-I, P-II and P-III fraction was 0.23, 0.24 and 1.1 respectively. The enzyme P-I fraction was purified 482 fold with a 22.8% yield by DEAE-Sephadex A-50, Sephadex G-75, Sephadex G-100 (1st and 2nd) column chromatography, and appeared homogeneous on polyacrylamide disc gel electrophoresis and ultracentrifugation.

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.136-141
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• 1989

A raw starch-digesting enzyme from Streptomyces sp. 4M-2 was purified by ammonium sulfate fractionation, DEAE-Sephadex A-50 column chromatography and Sephadex G-100 gel filtration. The specific activity of the purified enzyme was 51.22 RSU/mg protein and the yield was 4.5% of the total activity of the culture broth. The purified enzyme was found to be homogeneous by polyacrylamide gel electrophoresis and its molecular weight was estimated to be about 102, 000 daltons by SDS-polyacrylamide gel electrophoresis, The optimal temperature and pH for the enzyme activity were 42$^{\circ}C$ and PH 5.5, respectively. The enzyme had Km, value of 44.44mg/$m\ell$ for raw corn starch. The enzyme was activated by addition of calcium and barium ions. Corn amylose was degraded by the enzyme very easily and raw potato starch was also degraded easily. Main products of the enzymatic hydrolysis of raw corn starch were analyzed to be maltose and maltotriose. The enzyme was considered as $\alpha$-amylase.

• Journal of Nutrition and Health
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• v.17 no.1
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• pp.31-40
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• 1984

A new microassay was proposed for the determination of serum thiobarbituric acid(TBA) value greatly enhanced by ferric ion under anaerobic condition. One ${\mu}mole$ of $FeCl_{3}$ per $10{\mu}l$ of serum was added to the TBA reaction mixture containing serum protein precipitate. The reaction mixture was heated on boiling water-bath for 50min under $N_{2}$ flushing. The sensitivity of this assay was greatly enhanced by 40 times comparing with that of Yagi's method (1976). In favour of the enhancement, this test could be measured by colorimetry or spectrophotometry with the sample size of $10-20{\mu}l$ serum. The sensitivity and reproducibility were also improved by means of partial dehydration of the butanol extract with $(NH_{4})_{2}SO_{4}$ salting-out. Serum TBA values of healthy human at different age groups were determined by this proposed method.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.48-55
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• 2015

IMO to issue some restricted maritime legislation for reducing the adverse environmental impacts arising from such ship exhaust emissions. According to the IMO policy, every ship entering the Baltic SECAs has to equip the gas cleaning scrubber. The discharged waste solution by gas cleaning scrubber contains many types of salts, which to recover some valuable materials before disposal. This study try to achieve valuable salts including AN and AS throughout a few process such as selective organic solvents salting out, low temperature extraction and thermal evaporation. Amongst them, Thermal evaporation with repetition extraction using inorganic solvent was the most optimum to purify the extracted AN. This valuable salt was evaluated by Elemental analysis and Differential scanning calorimetry.

• The Korean Journal of Mycology
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• v.18 no.1
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• pp.7-12
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• 1990

Isolates of Penicillium expansum with reduced pathogenicity were arbitrarily selected among benomyl-resistant isolates in order to investigate relationship of their pectolytic enzyme acitivity with pathogenicity. In artificial medium, strongly pathogenic isolate $S_1$ and weakly pathogenic isolate $R_2$ produced considerable amonts of endo-polymethylgalacturonase, endo-polygalacturonase, pectin methyl-trans-eliminase, and polygalacturonate-trans-eliminase. No marked difference in enzyme activities was observed between two isolates. In apple medium, the activities of endo-polymethylgalacturonase and endo-polygalacturonase of isolate $S_1$ were over 6 times higher than those of isolate $R_2$. But pectin methyl-trans-eliminase and polygalacturonate-trans-­eliminase did not show a great difference. Activities of endo-polymethylgalacturonase and endo­polygalacturonase precipitated at 80-95% saturation of ammonium sulfate were highest, and addition of these enzyme solutions increased pathogenicity of weakly pathogenic isolates $R_{1-4}$.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.506-514
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• 1987

Peroxidase was purified to a homogeneous state from Castanea Semen by ammonium sulfate precipitation, DEAE-cellulose column chromatography, gel filtration on sephadex G-100 and HPLC, and the purification fold was 65.3. The molecular weight of the enzyme was estimated to be about 35,000 by HPLC. In properties of the enzyme which was purified up to sephadex G-100 column chromatography, the optimum pH and temperature were 5.0 and $50^{\circ}C$, respectively. By heating the enzyme at $80^{\circ}C$ for 1.73 min., the enzyme activity was decreased to 10%. The enzyme was active toward aromatic amines such as o-phenylenediamine and p-phenylendiamine. Kinetic studies indicated a Km of 2.6mM for o-phenylenediamine at an optimal hydrogen-peroxide concentration and a Km of 10mM for hydrogenperoxide at an optimal o-phenylenediamine concentration. Among the reagents tested, L-ascorbic acid and sodium L-ascorbate inhibited significantly the enzyme, while $Ca^{++}$ and $Ba^{++}$ activated the enzyme at the concentration of 1mM and 5mM.