• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.197-203
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• 2014

Various parameters such as solvent selection, concentration, solid/liquid ratio, soaking time, temperature, stationary, shaking conditions, and repeated extractions were investigated in order to determine the optimum extraction conditions of ${\beta}$-glucosidase from bagasse fermented by mixed culture of Aspergillus niger NRC 7A and Aspergillus oryzae NRRL 447. Among various solvents tested, non ionic detergents gave the best results than the inorganic or organic salt solutions and distilled water. The optimum conditions for extraction of ${\beta}$-glucosidase were 30 min soaking time at $40^{\circ}C$ under shaking condition at 150 rpm, with solid/liquid ratio 1:15 (w/v), which yielded $2882.74{\pm}95.52U/g$ fermented culture (g fc) of enzyme activity. With repeated washes under the above optimum conditions, the results showed that enzyme extracted in the $1^{st}$ and $2^{nd}$ washes represents about 90% of the total activity.

• Journal of Microbiology
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• v.35 no.2
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• pp.123-126
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• 1997

The aim of the present study was to optimize culture condition for the expression of lipocortin-1$_{1-185}$ in a recombinant of Escherichia coli using batch system. Plasmid (pHT22) carrying lipocortin-1$_{1-185}$ gene was well maintained in the recombinant with the addition of amplicillin as a selection pressures. Optimum temperature was 28$^{\circ}C$ for seed culture and 4$0^{\circ}C$ for main culture and the optimum pH was 7.0. The production of Lipocortin-1$_{1-185}$ was closely associated with cell growth and related to plasmid amplification.

• Journal of Microbiology
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• v.34 no.2
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• pp.179-183
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• 1996

Streptoccus Pneumoniae (pneumococcus), the most common cause of bacterial pneumonia, has an ample polysaccharide (PS) capsule that is highly antigenic and is the source of PS vaccine. This investigation was undertaken to optimize the culture conditions for the production of capsulard PS by type 1 pneumococcus. Among several culture media, brain heart infusion (BHI) and Casitone based media were found to support luxuriant growth of pneumococcus type 1 at the same level. Because BHI medium is rather expensive and more complex than the Casitone based media, the Casitone based media was uwed to study optimization of the culture condition. The phase of growth which accomodated maximum PS production was logarithmic phase. Concentrations of glucose greater than 0.2% did not ehnahce growth or PS production. Substitution of netrogen sources with other resources or supplementation of various concentrations of metal ion (with the exception of calcium ion) had adverse affects on growth and PS production. On the other hand, low level aeration was beneficial for increased PS production. Addition of 3 mg/1 concentration of methionine, phenylalanine, and threonine were found to enhance growth and PS production. The synerigistic effect of all the favorable conditions observed in pneumococcal growth assays provided a two-fold cummulative increase in capsular PS production.

• KSBB Journal
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• v.20 no.1 s.90
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• pp.66-70
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• 2005

Optimization of culture conditions for pigment production of Monascus purpureus P-57 mutant was investigated in liquid culture. The optimum composition of medium for the pigment production was $4\%$ rice power, $0.1\%$ beef extract, $0.03\%$ glutamic acid, $0.1\%\;MgSO_4{\cdot}7H_2O,\;0.25\%\;KH_2PO_4$, the optimum initial pH was 5.0. And the optimum culture conditions was at $30^{\circ}C$ for 8 days under 150 rpm with shaking. M. purpureus P-57 mutant produced the highest pigment as 356.04 units at red pigment and as 268.20 units at yellow pigment, and produced high cell mass as 15.00 g/L in liquid culture under the optimum conditions.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.548-561
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• 2020

Paecilomyces japonica is widely cultured to produce mycelium for medicinal and health food use. Illumination is an important factor in the growth and production of mycelium in submerged culture. The effects of different light-emitting diode (LED) combinations on the growth and cordycepin content as bioactive substances of mycelium were investigated. The results showed that the mycelium dry weights were lower under dark condition and red LED treatments. Dark condition, fluorescent light, and ultraviolet-A failed to increase the cordycepin content. Blue light was necessary to increase the cordycepin content, and a red-to-blue ratio of 3:7 induced the highest cordycepin content. The cordycepin contents of mycelium in submerged culture were significantly higher in a 12 h/day illumination time under red and blue (red-to-blue ratio of 3:7) LED treatments, showing an increase of up to 38% compared with those under the fluorescent-light control condition. The results demonstrated the roles of light with different wavelengths on the biosynthesis of cordycepin as bioactive substances. The low-heat release and replacement of traditional fluorescent lights with low-energy-consuming LEDs could increase the contents of bioactive substances. After optimization of the cordycepin production using response surface methodology (Box-Behnken design) to its canonical form, the optimum combination was found to be as follows: illumination time = 17.7 h/day, sugar content in the medium = 9.7 g/50 mL, and incubation time = 61.2 h. The model predicted a maximum response of 3779.2 ㎍/mL cordycepin yield.

• 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.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.425-434
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• 2006

The process of producing 1,3-preprandiol by microorganism continuous cultivation would attain its equilibrium state. How to get the highest concentration of 1,3-propanediol at that time is the aim for producers. Based on this fact, an optimization model is introduced in this paper, existence of optimal solution is proved. By infinite-dimensional optimal theory, the optimal condition of model is given and the equivalence between optimal condition and the zero of optimality function is proved.

• Journal of the Korean Society of Food Culture
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• v.28 no.4
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• pp.392-400
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• 2013

The purpose of this study was to determine the optimal amounts and mixing condition of skim milk powder (A), and roselle (B) for the production of yogurt prepared with roselle. The experiment was designed according to the central composite design for estimating the response surface method, which yielded ten experimental points, including two replicates for the skim milk powder and roselle. The physicochemical and mechanical analysis of each sample, including pH (P<0.001), titratable acidity (P<0.001), color (P<0.05), viscosity (P<0.001), showed significant differences. Antioxidant properties (total phenolic content, DPPH free radical scavenging activity) and viable cell counts of lactic acid were significantly different (P<0.05). The sensory measurements were significantly different in color, flavor, sourness, texture, and overall quality (P<0.05). The optimal formulation, calculated by numerical and graphical methods, was 7.82 g of skim milk powder and 2.09 g of roselle. From findings of this study, the roselle may be used in yogurt and can be applied for other food industries.

• KSBB Journal
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• v.17 no.3
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• pp.228-234
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• 2002

Acetobacter xylinum KJ1 efficiently producing bacterial cellulose(BC) In shaking culture was isolated from a rotten grape. The strain was used to investigate optimum operating conditions for increasing BC production and factorial design model was employed for the optimization. The results of experiments were statistically analyzed by SAS program. Reciprocal effects of each factors(carbon source concentration, shaking speeds(rpm), oxygen pressure, and CSL concentration) and culture condition of BC production were examined by getting regression equation of the dependent variable. Comparisons between experimental results and predicted results about BC concentration were done in total 24 experiments by combination of each factors using SAS program, and the correlation coefficients of BC concentration and BC yield were 0.91 and 0.81, respectively. The agitated cultures were peformed in various operation conditions of factors which affected considerably to BC production in jar fermentor. The results showed that BC concentration was 11.67 g/L in 80 hours cultivation under the condition of carbon source concentration : shaking speeds(rpm) : oxygen pressure : CSL concentration : 4% : 460 rpm : 0.28 : 6%. On the other hand BC yield was 0.42 g/g in 80 hours cultivation under the condition of carbon source concentration : shaking speeds(rpm) : oxygen pressure : CSL concentration : 4% : 564 rpm : 0.21 : 2%. The BC production could be enhanced up to more than 2.4 times by factorial design. The result of a verifying experiment under the optimal conditions determined by the factorial design to the BC production showed that the model was appropriate by obtaining BC concentration of 11.47 g/L in the optimum condition.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.459-464
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• 2004

The objective of this study is to improve cephalosporin C (CPC) production byoptimization of medium and culture conditions. A statistical method was introduced to optimize the main culture medium. The main medium for CPC production was optimized using a statistical method. Glucose and corn steep liquor (CSL) were found to be the most effective factors for CPC production. Glucose and CSL were optimized to 2.84 and $6.68\%$, respectively. CPC produc­tion was improved $50\%$ by feeding of $5\%$ rice oil at day 3rd and 5th day during the shake flask culture of C acremonium M25. The effect of agitation speeds on CPC production in a 2.5-L bio­reactor was also investigated with fed-batch mode. The maximum cell mass (54.5 g/L) was obtained at 600 rpm. However, the maximum CPC production (0.98 g/L) was obtained at 500 rpm. At this condition, the maximum CPC production was improved about $132\%$ compared to the re­sult with batch flask culture.