• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.51-56
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• 1998

A bacteium, KP-6408, capable of hydrolyzing fibrin was isolated from Chungkook-jang, which was possibly identified as a strain of Bacillus sp. The effects of culture condition and medium composition on the enzyme production were investigated. Among nitrogen sources tested, yeast extract was the most effective for the enzyme production, and the level of the concentration for the optimal enzyme production was 0.2%(w/v). For carbon sources, glucose was the best for the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the organism at the liquid medium of the initial pH 8.0 and temperature of 4$0^{\circ}C$. In Chungkook-jang fermentation, the enzyme was maximally produced when incubated at 35$^{\circ}C$ for 24 hrs using soybean as a solid medium. The addition of various rice starch to the soybean in Chungkook-jang fermentation lowered the enzyme production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.181-184
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• 2003

We investigated the effect of ethanol on the production of cellulose and acetic acid fermentation by Gluconacetobacter persimmonensis KJ145. Results showed that bacterial cellulose productivity was highest when 2% ethyl alcohol was added to apple-juice medium. For acetic acid production, 7% ethyl alcohol was needed. Optimal concentration of ethyl alcohol was 5% for simultaneous production of bacterial cellulose and acetic acid. For simultaneous production of bacterial cellulose and acetic acid, optimal nitrogen source and optimal concentration were corn steep liquor and 15% (w/v), respectively Optimal culture time for simultaneous production of bacterial cellulose and acetic acid was 14 days. At the optimal condition, Cluconacetobacter persimmonenis KJ145 produced 7.55 g/L of bacterial cellulose (dry weight).

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.130-134
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• 2005

Isolation of a pigment overproducing mutant, P-57, by ultraviolet irradiation of Monascus purpureus KCCM 60016 and investigation of the optimal conditions for pigment production of the mutant were carried out. P-57 mutant produced pigment on solid state culture. Unpolished rice was the best cereal source for pigment production among eight kinds of tested cereal sources for the solid culture of the mutant. The optimal culture condition for pigment production were obtained from the cultivated at $30^{\circ}C,\;90\%$ humidity for 30 days. The P-57 mutant strain showed the best pigment productivity of 160.0 unit at red pigment, 193.6 unit at orange pigment, and 141.6 unit at yellow pigment on solid state culture under optimal condition.

• Journal of Korean Society for Quality Management
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• v.32 no.3
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• pp.109-125
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• 2004

This paper deals with an optimal process control problem in production of hull structural steel plate with high defective rate. The main quality characteristic(dependent variable) is the internal quality(defect) of plates and is dependent on process parameters(independent variables). The dependent variable(quality characteristics) has three categorical ordinal data and there are 35 independent variables(29 continuous variables and 6 categorical variables). In this paper, we determine the main factors and to develop the mathematical model between internal quality predicted probabilities and the main factors. Secondly, we find out the optimal process condition of main factors through analysis of variance(ANOVA) using simulation. We consider three models to obtain the main factors and the optimal process condition: linear, quadratic, error models.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.12
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• pp.2216-2225
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• 1992

In recent years, machining turns to flexible manufacturing. Industry in machining requires to increase machining productivity and to reduce costs. To adapt this trend it is necessary to optimize machining condition. Even though many researches in this are introduced various way to set the optimal condition, still there are not enough. Therefore this research was done to select the optimal cutting condition for industry, and to develope the computer program to select the optimal cutting condition automatically. Also, this program was applied to many companies, and compare costs per minute. The results of this research will contribute to increase machining productivity of various companies with the automatic selection of optimal cutting condition.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.46-51
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• 2007

Lipases are industrially useful versatile enzymes that catalyze numerous different reactions. Among lipases functioning under extreme conditions, alkaline lipase is useful in detergent industry. Lipase from yeast strain Yarrowia lipolytica NRRL Y-2178 was most active under alkaline condition, and initial medium pH for most lipase production was also alkaline [Lee et al., 2007, J Microbiol Biotechnol, 17(6)]. High lipase production was achieved using Y. lipolytica NRRL Y-2178. Optimal incubation time for lipase production at $25^{\circ}C$ was 72 h. Optimal temperature, when incubated for 72 h, was $27.5^{\circ}C$. Lipase production but not cell growth was very sensitive to concentrations of glucose and glycerol as efficient carbon sources, showing optimal concentrations of 1.0 and 1.5% (w/v), respectively. Lipase production was highly stimulated by $Ca^{2+},\;K^+,\;and\;Na^+$, but was inhibited by $Co^{2+},\;Cu^{2+},\;Mn^{2+},\;Na^+,\;and\;Fe^{2+}$. Maximum lipase production at 0.1 mM $Ca^{2+}$ for 72 h incubation at $27.5^{\circ}C$ was 649 units/mL.

• KSBB Journal
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• v.13 no.5
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• pp.491-496
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• 1998

The production of fibrinolytic enzyme from Bacillus subtilis BK-17 was studied in the shake flask cultures. The important medium components studied include nitrogen source, carbon source and inorganic salts. The environmental conditions include initial pH, temperature, shaking speed and working volume. Among various N-sources, C-sources and inorganic salts tested, soybean flour, D-glucose and Na2HPO4 gave the best results, and their optimal concentrations were 1.5%, 0.5% and 0.05%, respectively. The optimal pH and temperature were 9.0 and 37$^{\circ}C$. With decreasing working volume in the range of 25∼100ml in the 250ml flask or increasing shaking speed in the range of 100∼300rpm, the enzyme production was greatly enhanced. The enzyme activity under the optimal conditions was about 1400I.U./ml with urokinase as a standard.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1215-1220
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• 2004

Reactive distillation (RD) is a combination process where both separation and reaction are considered simultaneously in a single vessel. This kind of combination to enhance the overall performance is not a new attempt in the chemical engineering areas. The recovery of ammonia in the classic Solvay process for soda ash of the 1860s may be cited as probably the first commercial application of RD. The RD system has been used for a long time as a useful process and recently the importance of the RD is enlarged more and more. In addition to that, the application fields of RD are diversely diverged. To make the most of the characteristic of RD system, we must decide the best operating condition under which the process shows the most effective productivity and should decide the best control algorithm which satisfies an optimal operating condition. Phosgene which is a highly reactive chemical is used for the production of isocyanates and polycarbonates. Because it has high reactivity and toxicity, its utilization is increasingly burdened by growing safety measures to be adopted during its production. Dimethyl Carbonate (DMC) was proposed as a substitute of phosgene because it is non-toxic and environmentally benign chemical. In this study, RD is used for DMC production process and the transesterification is performed inside of column to produce DMC. In transesterification, the methanol and ethylene carbonate (EC) are used as the reactants. This process use homogeneous catalyst and the azeotrope exists between the reactant and product. Owing to azeotrope, we should use two distillation columns. For this DMC production process, we can suggest two configurations. One is EC excess process and the other is methanol excess process. From the comparison of steady state simulation results where the Naphtali-Sandholm algorithm is used, it showed the better performance to use the methanol excess process configuration than EC excess process. Then, the dynamic simulation was performed to be based on the steady state simulation results and the optimal control system was designed. In addition to that, the optimal operating condition was suggested from previous results.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.130-136
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• 1998

An Immunostimulating polysaccharide was produced from the suspension culture of Angelica gigas H4, plant cells. In order to enhance the polysaccharide production by the A. gigas cell culture, medium composition and physical conditions were optimized. Schenk and Hildebrandt (SH) medium was selected as an optimal basal medium for the growth of A. gigas. The maximum cell and polysaccharide concentration obtained in SH medium were 15.8 g DCW/l and 0.85 g polysaccharide/l, respectively, at $25^{\circ}C$ under dark condition. For the enhanced polysaccharide production, a polysaccharide production medium (PPM) was established by modifying Gamborg B5 medium with optimized carbon sources, growth regulators, organic and inorganic elements. Optimal initial pH and temperature were 6.0-6.6 and $20^{\circ}C$, respectively, and the dark condition was better than the light condition. The maximum polysaccharide concentration of 1.5 g/l could be obtained through the optimization of the medium composition and physical conditions.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.211-214
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• 2002

The optimal condition for the production of DXAMase, containing the both characteristics of dextranase and amylase, was studied based on different levels of pH, temperature, and aeration rate. Response surface methodology was applied to find the optimatic condition showing the relationship between the fermentation response(dextranase and amylase activity of DXAMase) and the fermentation variables(pH, temperature, and agitation rate). In case of dextranase activity, the condition of pH 4.06, $28.08^{\circ}C$, and 235.14 rpm showed the highest activity, 2.26 U/ml, and for amylase activity, the condition of pH 4.01, $27.96^{\circ}C$, and 212.01 rpm showed the highest activity, 3.52 U/ml. For the production of DXAMase, dextranase and amylase, the optimum condition was pH 4.06, $28.08^{\circ}C$, and 234.80 rpm.