• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.187-191
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• 2005

발효기에서의 균사체 생장과 세포외다당류의 생산을 위한 최적 배양조건을 조사하기 위하여 회분식 반응기를 이용하여 연구한 결과 최적 회전속도와 통기량은 각각 200 rpm과 1.5 vvm 었다. 최적 배양 환경하에서 5L발효기(working volume 2 L)에서 배양한 결과 각각 10.21 g/L 와 3.56 g/L의 mycelial growth와 exo- polysaccharide를 얻었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.140-143
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• 2005

This study was concerned with the optimization of liquid culture conditions for mycelial growth and polysaccharide production and its physicochemical properties in Cordyceps militaris. The one factor at a time method was adopted to investigate the effects of medium composition, environmental factors and C/N ratio. Among the these varialbles, glucose 80g/L, yeast extract 10g/L, $MgSO_4{\cdot}7H_{2}O\;0.5g/L$, $KH_{2}PO_4\;0.5g/L$ were proved to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature, initial pH, working volume were identified to be $24^{\circ}C$, 7.0 and 100ml, respectively. Under the optimal conditions, the strategies in shake flask culture and 5L jar fermentor led to mycelial growth of 29.43 g/L, 28.88g/L and polysaccharide production of 2.53g/L, 6.38 g/L, respectively. Among the phisicochemical properties, relative concentrations(w/v) of total sugar, uronic acid, protein and hexoseamine were identified to be 74.07%, 1.13%, 0.91%, and 0.46%, respectively. The fraction of neutral and acidic polysaccharide were identified to be 81.9% and 18.1%, respectively.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1930-1936
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• 2007

A sequential optimization strategy based on statistical experimental designs was employed to enhance the production of cyclosporin A (CyA) by Tolypocladium inflatum DSMZ 915 in a submerged culture. A 2-level Plackett-Burman design was used to screen the bioprocess parameters significantly influencing CyA production. Among the 11 variables tested, sucrose, ammonium sulfate, and soluble starch were selected, owing to their significant positive effect on CyA production. A response surface methodology (RSM) involving a 3-level Box-Behnken design was adopted to acquire the best process conditions. Thus, a polynomial model was created to correlate the relationship between the three variables and the CyA yield, and the optimal combination of the major media constituents for cyclosporin A production, evaluated using the nonlinear optimization algorithm of EXCEL-Solver, was as follows (g/l): sucrose, 20; starch, 20; and ammonium sulfate, 10. The predicted optimum CyA yield was 113 mg/l, which was 2-fold the amount obtained with the basal medium. Experimental verification of the predicted model resulted in a CyA yield of 110 mg/l, representing 97% of the theoretically calculated yield.

• Journal of Applied Biological Chemistry
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• 제58권3호
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• pp.209-218
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• 2015

Fructooligosaccharides have been mainly produced by microbial fructosyltransferases (FTase) enzymes. The present work focuses on the optimization of medium composition and cultivation parameters affecting FTase produced by Penicillium aurantiogriseum AUMC 5605 in shake flask cultivation. FTase production was optimized in two steps using DeMeo's fractional factorial design. A 1.46-fold increase in FTase production (105.4 U/mL) was achieved using the optimized culture medium consisting of (g/L): sucrose, 600; yeast extract, 10; $K_2HPO_4$, 5; $MgSO_4{\cdot}7H_2O$, 0.5; $(NH_4)_2SO_4$, 1.0 and KCl, 0.5. The obtained results showed that the maximum FTase enzyme activity was produced at initial cultivation pH values ranging from 6.0-6.5, at agitation speed of 200 rpm and using vegetative fungal cells as inoculum. Moreover, results showed that optimization of medium composition and some cultivation parameters resulted in an increase of about 93.7% in the enzyme activity than the nonoptimized cultivation conditions after 96 h of cultivation. Additionally, maximum production and specific production rates recorded 2340 U/L/h and 102 U/L/h/g cells, respectively.

• 미생물과산업
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• 제19권4호
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• pp.14-26
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• 1993

Optimizing protein production in recombinant E. coli strains involves manipulation of genetic and environmental factors. In designing a production system, attention must be paid to gene expression efficiency, culture conditions and bioreactor configuration. Although not much emphasis was given to the physiology of host strains in this review, an understanding of the relationship between the physiology of host cell growth and the overproduction of a cloned gene protein is of primary importance to the improvement of the recombinant fermentation processes. Sometimes it is desirable to make use of gene fusion systems, e.g. protein A, polypeptide, gutathione-S-transferase, or pneumococcal murein hydrolase fusion, to facilitate protein purification.

• 한국식생활문화학회지
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• 제32권1호
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• pp.58-65
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• 2017

This study was conducted to optimize the conditions of a sweet rice paste as a replacement of red bean paste recipe using the central composite design of response surface methodology (RSM). Ten experimental recipes with two reference points (rice flour and sugar), were selected, and the physical and sensory characteristics of a sweet rice paste were measured. In the Rapid Visco Analyzer test, breakdown value was the highest in rice flour (105.73 RVU). Sweetness significantly increased with addition of sugar contents (p<0.0002) and viscosity increased with addition of rice flour contents (p<0.0185). Moisture contents decreased with increasing contents of rice flour and sugar, whereas yellowness and redness tend to increase. In the sensory evaluation test, quadratic models for color (p<0.01865), sweetness (p<0.0399), thickness (p<0.0073), and overall acceptability (p<0.0249) were approved as independent for the rice flour and sugar contents. In conclusion, the optimal mixing ratio of sweet rice paste was determined to be 45.38 g of rice flour and 77.95 g of sugar.

• 한국식생활문화학회지
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• 제27권6호
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• pp.710-718
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• 2012

The purpose of this study was to investigate the antioxidative effects of Opuntia humifusa and determine the optimal mixing ratio of Opuntia humifusa powder and eggs for the preparation of pasta. In regard to its antioxidant effects, Opuntia humifusa powder had a total phenolic content and DPPH free radical scavenging activity of 6.64 mg/g and 90.12%, respectively. We used response surface methodology to obtain ten experimental points (including two replicates for Opuntia humifusa powder and egg) and Opuntia humifusa pasta formulation was optimized using rheology. Yellowness (p<0.001) displayed a linear model pattern, whereas lightness (p<0.01) and redness (p<0.01) were described by a quadratic model pattern. Mechanical properties showed significant values in hardness (p<0.5), chewiness (p<0.5), gummiess (p<0.5), and cohesiveness (p<0.5). The sensory evaluation parameters showed significant differences in color (p<0.5), appearance (p<0.5), flavor (p<0.5), texture (p<0.5) and overall quality (p<0.5). The optimum formulations processed by numerical and graphical optimization were found to be 7.30 g of Opuntia humifusa powder and 31.55 g of egg.

• 한국식생활문화학회지
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• 제26권3호
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• pp.283-294
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• 2011

The purpose of this study was to determine the optimal mixing conditions for three different amounts of mulberry juice, sugar, and agar powder for Yanggaeng prepared with mulberry juice. The experiment was designed according to the central composite design for estimating the response surface, which demonstrated 16 experimental points including 2 replicates for mulberry juice, sugar and agar powder each?? The mechanical and sensory properties of test materials were measured, and these values were applied to the mathematical models. A canonical form and perturbation plot showed the influence of each ingredient on the final product mixture. Measurement results of the mechanical properties showed a significant increase or decrease?? in pH, sugar content, water content, viscosity, l-value, a-value, b-value, hardness, springiness, chewiness, gumminess, cohesiveness. Also the sensory measurements showed a significant improvement?? in appearance, flavor, color, sweetness, texture, overall quality. As a result, the optimum formulation by numerical and graphical methods was calculated as mulberry juice 41.99 g, sugar 90.00 g, agar powder 3.18 g.

• Food Science and Biotechnology
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• 제17권3호
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• pp.587-593
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• 2008

Microbial exopolysaccharide (EPS) is a biothickener that can be added to a wide variety of food products, where it serves as a viscosifying, stabilizing, emulsifying, and gelling agent. The objective of this study was to investigate the optimum conditions of pH, incubation temperature, and whey protein concentration (WPC) for EPS production by Lactobacillus rhamnosus ATCC 9595. We found that maximal EPS production was achieved at a pH of 5.5 and temperature of $37^{\circ}C$. At the same fermentation conditions, EPS production was affected by the addition of L. rhamnosus GG (a weak-EPS producer). After growth for 24 hr, total EPS production was $583{\pm}15.4mg/L$ in the single culture system, and $865{\pm}22.6\;mg/L$ in the co-culture system with L. rhamnosus GG. Based on the presence of WPC, EPS production dramatically increased from $583{\pm}15.4$ (under no WPC supplementation) to $1,011{\pm}14.7\;mg/L$ (under supplementation with 1.0% WPC). These results suggest that WPC supplementation and the co-culture systems coupled with small portions of weak-EPS producing strain can play an important role in the enhancement of EPS production.

• 한국수정란이식학회지
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• 제29권3호
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• pp.229-234
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• 2014

The aim of the present study was to compare two different serum-free media, modified synthetic oviduct fluid (mSOF) and modified potassium simplex optimization medium (mKSOM) containing 20% RD (RPMI1640 + DMEM, 1:1 v/v) (RD-mKSOM), for in vitro culture (IVC) of bovine embryos. After in vitro maturation and fertilization, the presumptive zygotes were cultured in two different serum-free conditions for 7 days and 9 days to evaluate blastocyst formation and hatching, respectively. Serum supplemented conventional CR2 medium was used as control. After 7 day of culture, there was no significant difference in cleavage and blastocyst formation rates among three groups (mSOF, 59.3 and 30.1%; RD-mKSOM, 65.0 and 41.5%; control, 51.6 and 38.0%, respectively). Hatching rate was significantly higher in control (69.0%) than other experimental groups (mSOF, 22.0%; RD-mKSOM, 39.5%) (P<0.0001 and P<0.001, respectively). Although both serum-free conditions showed lower hatching rates than serum-added control, in serum-free groups, RD-mKSOM showed significantly higher hatching rate than mSOF (P<0.001). In addition, one-step using RD-mKSOM may facilitate IVC procedure than two-step culture system. In conclusion, the results indicate that one-step RD-mKSOM is more suitable defined culture system for IVC of bovine embryos than two-step mSOF.