• 한국식생활문화학회지
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• 제19권2호
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• pp.193-199
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• 2004

The purpose of this study was to determine the organoleptic charateristics of cauliflower pickles made in various compounding ratio according to central conposite design for optimum organoleptic characteristics of the cauliflower pickles. The optimum mixing condition of cauliflower pickles were optimized, using central composite design with 3 variables and 3 levels, by response surface methodology. The various kinds of cauliflower pickle were made in various compounding ratio of vinegar, salt and sucrose - critical ingredients of pickle recipe - and were presented to reliable panels, who graded the subjects in 7 degrees for 4 items : color, flavor, hardness and overall quality. The optimum mixing conditions of cauliflower pickle were 603.50g of vinegar, 80.13g of salt and 251.07g of sucrose in the maximum point of overall quality.

• 한국미생물·생명공학회지
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• 제26권3호
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• pp.250-256
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• 1998

D-Tagatose의 생산 가능성이 있는 미국 종균협회(ATCC)와 한국 유전자은행(KCTC)에서 구입한 균주 35 종류를 사용하여 D-galactose로부터 D-tagatose의 생산을 조사하였다. 여러 균주 중에 발효시간이 짧고 D-tagatose의 생산량이 높은 Enterobactor agglomerans ATCC 27987을 D-tagatose 생산 균주로 선정하였다. 선정된 균을 사용하여 D-tagatose의 생산에 영향을 주는 배양 조건을 최적화 하였다. 여러 가지 탄소원 중에서 D-galactose가 D-tagatose의 생산량이 가장 높게 나타났고 그 농도를 달리하였을 때 D-galactose의 농도가 증가할수록 D-tagatose의 생산량과 균체농도가 증가하였다. 20 g/l의 D-galactose 배지에서 여러 가지 질소원이 D-tagatose의 생산에 미치는 영향을 살펴본 결과 D-tagatose의 생산량은 유기 질소원의 경우 yeast extract가 가장 높았고 무기 질소원의 경우 (NH$_4$)$_2$SO$_4$가 높게 나타났다. D-Tagatose의 생산량이 가장 높게 나타난 질소원인 yeast extract를 선택하여 농도별 실험을 수행하여 최적 yeast extract의 농도를 5.0 g/l로 결정하였다. (NH$_4$)$_2$SO$_4$를 yeast extract 5.0 g/l가 함유된 배지에 농도별로 첨가하여 2.0 g/l에서 최대 D-tagatose의 생산량을 얻었다. 또한, 무기염의 영향을 조사하여 KH$_2$PO$_4$ 5.0 g/l, $K_2$HPO 5.0 g/l, MgSO$_4$.7$H_2O$ 5.0 mg/l의 최적 D-tagatose 생산 조건을 결정하였다. 배지최적화를 통하여 최적 배지로 D-galactose 20 g/l, yeast extract 5.0 g/l, (NH$_4$)$_2$SO$_4$ 2.0 g/l, KH$_2$PO$_4$ 5.0 g/l, $K_2$HPO$_4$ 5.0 g/l, MgSO$_4$.7$H_2O$ 5 mg/l를 선정하였다. 최적 배지에서 배양 환경이 D-tagatose의 생산에 미치는 영향을 조사하여 초기 pH 6.0, 배양 온도 3$0^{\circ}C$, 교반속도 150 rpm의 최적 배양 조건을 결정하였고 이 조건에서 배양시간 24시간에 D-galactose 20 g/l로부터 D-tagatose의 0.41 g/l를 얻을 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권1호
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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 Microbiology and Biotechnology
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• 제14권4호
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• pp.665-672
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• 2004

D-Ribose is a five-carbon sugar used for the commercial synthesis of riboflavin, antiviral agents, and flavor enhancers. Batch fermentations with transketolase-deficient B. subtilis JY1 were carried out to optimize the production of D-ribose from xylose. The best results for the fermentation were obtained with a temperature of $37^{\circ}C$ and an initial pH of 7.0. Among various sugars and sugar alcohols tested, glucose and sucrose were found to be the most effective for both cell growth and D-ribose production. The addition of 15 g/l xylose and 15 g/l glucose improved the fermentation performance, presumably due to the adequate supply of ATP in the xylose metabolism from D-xylulose to D-xylulose-5-phosphate. A batch culture in a 3.7-1 jar fermentor with 14.9 g/l xylose and 13.1 g/l glucose resulted in 10.1 g/l D-ribose concentration with a yield of 0.62 g D-ribose/g sugar consumed, and 0.25 g/l-h of productivity. Furthermore, the sugar utilization profile, indicating the simultaneous consumption of xylose and glucose, and respiratory parameters for the glucose and sucrose media suggested that the transketolase-deficient B. subtilis JY1 lost the glucose-specific enzyme II of the phosphoenolpyruvate transferase system.

• KSBB Journal
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• 제30권4호
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• pp.166-174
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• 2015

In this study, an efficient whole cell-based biotransformation for the production of liquiritigenin was developed using Laetiporus sulphureus CS0218 as biocatalyst and aqueous extracts of Glycyrrhiza uralensis as co-substrate, respectively. In order to determine the efficacy of this method, the optimal bioconversion conditions including mycelial growth, three important enzyme activities (${\beta}$-glucosidase, ${\alpha}$-rhamnosidase and ${\beta}$-xylosidase), and apparent viscosity of culture broth were monitored. After optimization, aqueous extracts of G. uralensis were added to the culture medium to directly produce algycone liquiritigenin. By applying this strategy, 67.5% of liquiritin was converted to liquiritigenin at pH 3.0 after 9 days of incubation and finally liquiritigenin was purified from the reaction mixture. And then, their biological activities including anti-oxidant and superoxide dismutase were observed. In fact, purified liquiritigenin was capable of bi-directional functions (i.e., either up-regulation or down-regulation of SIRT1 which is associated with aging). The results indicate that this strategy would be beneficial to produce biologically active liquiritigenin and could be used in pharmaceutical, cosmetic and food applications.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.695-703
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• 2008

A locally isolated thermophile, Geobacillus sp. SAB-40, producing thermostable extracellular amylase constitutively and an induced intracellular ${\beta}$-galactosidase was characterized and identified based on 16S rRNA sequencing. A phylogenetic analysis then revealed its closeness to Geobacillus stearothermophilus. To evaluate the effect of the culture conditions on the coproduction of both enzymes by G stearothermophilus SAB-40, a Plackett-Burman fractional factorial design was applied to determine the impact of twenty variables. Among the tested variables, $CaCI_2$, the incubation time, $MgSO_4{\cdot}7H_2O$, and tryptone were found to be the most significant for encouraging amylase production. Lactose was found to promote ${\beta}$-galactosidase production, whereas starch had a significantly negative effect on lactase production. Based on a statistical analysis, a preoptimized medium attained the maximum production of amylase and ${\beta}$-galactosidase at 23.29 U/ml/ min and 12,958 U/mg biomass, respectively, which was 3-and 2-fold higher than the yield of amylase and lactase obtained with the basal medium, respectively.

• KSBB Journal
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• 제8권5호
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• pp.446-451
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• 1993

에탄올 발효에서의 주요 환경 인자인 온도, pH, 통 기속도, 초기 포도당 농도, 효모추출물 농도 등이 세 포성장과 에탄올 및 부산물 생성에 미치는 영향에 대하여 연구하였다. 통기속도가 증가함에 따라 최대 세포농도는 거의 션형적으로 증가하는 반면 최대 에 탄올 및 부산물 농도는 감소하였다. 배양온도가 높아질수록 세포의 성장속도와 에탄올 빛 부산물 생성 속도는 증가하는 반면 최종 세포농도와 최종 에탄올 및 부산물 농도는 오히려 낮게 나타난다. 배지내의 pH 벙위가 4.0 이하냐 6.0 이상으로 되연 세포성장, 에탄올 및 부산물 생성이 급격히 감소하였고 pH 4.5 에서 세포농도와 에탄올 및 부산물 농도가 최대치를 나타내었다. 초기 포도당 농도의 증가에 따라 세포 농도와 에탄올 및 발효 부산물 농도는 증가하였으나 수율은 오히려 감소하였다. 효모추출물 농도가 증가 하면 세포성장은 증가하나 에탄올 및 부산물의 생성 은 오히려 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1252-1260
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• 2020

(R)-2-(4-hydroxyphenoxy)propionic acid (HPOPA) is a key intermediate for the preparation of aryloxyphenoxypropionic acid herbicides (R-isomer). In order to improve the HPOPA production from the substrate (R)-2-phenoxypropionic acid (POPA) with Beauveria bassiana CCN-A7, static cultivation and H₂O₂ addition were attempted and found to be conducive to the task at hand. This is the first report on HPOPA production under static cultivation and reactive oxygen species (ROS) induction. On this premise, the cultivation conditions and fermentation medium compositions were optimized. As a result, the optimal carbon source, organic nitrogen source, and inorganic nitrogen source were determined to be glucose, peptone, and ammonium sulfate, respectively. The optimal inoculum size and fermentation temperature were 13.3% and 28℃, respectively. The significant factors including glucose, peptone, and H₂O₂, identified based on Plackett-Burman design, were further optimized through Central Composite Design (CCD). The optimal concentrations were as follows: glucose 38.81 g/l, peptone 7.28 g/l, and H₂O₂ 1.08 g/l/100 ml. Under the optimized conditions, HPOPA titer was improved from 9.60 g/l to 19.53 g/l, representing an increase of 2.03-fold. The results obtained in this work will provide novel strategies for improving the biosynthesis of hydroxy aromatics.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1527-1532
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• 2016

Strain SPF4211, having hyaluronidase (HAase) inhibition activity, was isolated from P. davidiana (Carriere) Franch fruit (PrDF) sugar extract. The phenotypic and biochemical properties based on 16S rDNA sequencing and an API 50 CHB kit suggested that the organism was B. subtilis. To optimize the HAase inhibition activity of PrDF extract by fermentation of strain SPF4211, a central composite design (CCD) was introduced based on three variables: concentration of PrDF extract (X₁: 1-5%), amount of starter culture (X₂: 1-5%), and fermentation time (X₃: 0-7 days). The experimental data were fitted with quadratic regression equations, and the accuracy of the equations was analyzed by ANOVA. The statistical model predicted the highest HAase inhibition activity of 37.936% under the optimal conditions of X₁ = 1%, X₂ = 2.53%, and X₃ = 7 days. The optimized conditions were validated by observation of an actual HAase inhibition activity of 38.367% from extract of PrDF fermented by SPF4211. These results agree well with the predicted model value.

• KSBB Journal
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• 제25권6호
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• pp.539-546
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• 2010

In this work, mass production of Bacillus licheniformis SCD121067 through medium optimization by statistical experimental method was studied. First, galactose, yeast extract and potassium phosphate dibasic were selected as carbon, nitrogen and phosphate sources for mass production of B. licheniformis SCD121067 by using one factor at a time method. Second, according to the result of Plackett-Burman experimental design, key factors was yeast extract and $K_2HPO$. Finally, the response surface methodology was performed to obtain the optimum concentrations of two selected variables. The optimized medium composition consisted of 20 g/L galactose, 36 g/L yeast extract, 0.41 g/L $K_2HPO4$, 0.25 g/L $Na_2CO_3$, 0.4g/L $MgSO_4$ and 0.01g/L $CaCl_2$. Dry cell weight (15.4 g/L) by optimum production medium were increased 10 times, as compared to that determined with basic production medium (1.5 g/L). Fermentation conditions were examined for the mass production of B. licheniformis. The effect of temperature, agitation speed, pH and aeration rate on the mass production of B. licheniformis were also studied in a batch fermenter which was carried out in a 2.5 L bioreactor with a working volume of 1.5 L containing optimized production medium. As a result, dry cell weight of batch culture was 30.7 g/L at $42^{\circ}C$, 300 rpm, pH 8.0 and 2 vvm.