• BMB Reports
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• 제36권5호
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• pp.493-498
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• 2003

The scFv antibody towards the Burkholderia pseudomallei exotoxin was previously constructed by phage display and exhibited good specificity towards the exotoxin. We report here the optimization of the scFv expression in an E. coli expression system. Four different E. coli strains (ER2537, TG1, HB2151, and XL1-Blue) were examined for optimal expression of the scFv protein. Two types of carbon source (i.e. 0.2% glucose and 0.2% glycerol) were also tested for their ability to induce the scFv expression. Cells that carried the scFv construct were grown at $30^{\circ}C$ and induced with 0.05 mM IPTG. The expression was then monitored by SDS-PAGE, Western blotting, and indirect ELISA. The Western blot profile showed different levels of the scFv expression among the host strains; XL1-Blue exhibited the highest level of the scFv protein expression. Glycerol at a concentration of 0.2% (v/v) significantly increased the scFv protein expression level when compared to 0.2% (w/v) glucose. Further optimization demonstrated that the scFv protein expression in XL1-Blue was the most optimal with a glycerol concentration as low as 0.05%. However, by indirect ELISA, only the scFv protein that was expressed in 0.2% (v/v) glycerol exhibited high specificity towards the Burkholderia pseudomallei exotoxin.

• Journal of Nutrition and Health
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• 제30권3호
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• pp.252-265
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• 1997

This study was performed to investigate effect of dietary fibers in rice and barley on glucose, lipid and cadmium (Cd) metabolism in the rat. Fifty-six male Spague-Dawley rats weighing 244.6$\pm$2.7g were blocked into eight groups according to body weight and raised for four weeks with diets containing 0 or 0.04%(w/w) CdCl2 and four different carbohydrate sources, starch, rice flour, barley flour and mixture of rice and barley flour(7 : 3, w/w). Total dietary fibers and $\beta$-glucan contents of barley were about three times higher than those of rice (10.75% vs. 3.94%, 3.11% vs. 1.06%, respectively). Food intake, weight gain, food efficiency ratio, liver and kidney weights were lower in Cd exposed groups, and barley group among Cd exposed animals showed highest weight gain, food efficiency ratio and organ weights. Fasting serum glucose levels were not significantly different among groups, Serum cholesterol level was lowest in Cd exposed barley group. Serum HDL-cholesterol level was higher in none-Cd exposed starch and barley groups, and HDL-cholesterol : total cholesterol ratios were higher in none-Cd rice and mixed flour groups than other groups. Liver total lipid and triglyceride levels were lowest in barley groups regardless of Cd administration. Fecal total lipid, cholesterol and triglyceride excretions were high in barley and mixed flour groups. Liver Cd concentrations were low in Cd exposed barley and mixed flour groups. In Cd exposed barley group, fecal weight and Cd excretion were highest and Cd retention ratio was lowest among groups. Small intestine metallothionein(MT) concentration was highest in Cd exposed rice group, and kidney MT concentration was highest in Cd exposed barley group. In conclusion, cereals showed different effects on lipid and Cd metabolism that might be mediated by dietary fibers in cereals. Especially $\beta$-glucan-rich barley group showed greatest lipid and Cd lowering effects by increasing fecal lipids and Cd excretions.

• KSBB Journal
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• 제10권2호
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• pp.196-203
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• 1995

국내에서 선멸된 Streptomyces sp. 809-11 균주의 항생물질 polyoxins의 생합성 능력을 향상시키기 위하여 주요 영양원에 따른 균체의 중식 및 polyoxins 의 생합성에 미치는 영향을 조사하였다. 본 실험결 과 가용성 전분만을 사용한 배지에서는 초기 대수척 성장기의 균체량은 증가하였으나 polyoxins의 생합 성량은 적게 나타났으며, 포도당만을 이용한 경우는 사상균사체의 형성을 증가시켜 polyoxins의 생합성 량을 증가시켰으나 초기 균체의 성장률은 매우 저조 하였다. 따라서 균체의 성장과 polyoxins의 생합성 향상 두 가지 측면을 모두 고려하여 볼 때 탄소원 으로 가용성 전분과 포도탕을 혼용하여 사용하는 것이 바람직한 것으로 나타났다. 질소원으로 사용한 $(NH_2)_4S0_4$는 비교적 고놓도인 151.4mM에서 최대 항생제 생합성량을 보여주었으며, 인산염으로 사용된 $K_2HPO_4$는 0.5mM 정도에서 최적의 poly oxms 생합성을 보여 주였다. 유가식배양을 도입하 여 초기에는 균체 성장을 위하여 전분과 포도탕이 함유된 배지에서 배양하였고, 탄소원의 고갈시점에 는 사상 균사체의 분화 촉진을 위하여 포도당을 공 급한 결과 polyoxins의 생합성량을 회분식 배양에 비하여 두 배 이상으로 증가시켰다.

• Journal of the Korean Wood Science and Technology
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• 제43권5호
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• pp.578-590
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• 2015

The present study examines the influence of slurry composting and biofiltration liquid fertilizer (SCBLF) treatment on the biomass characteristics of yellow poplar, and the optimization of organosolv pretreatment for sugar production. After SCBLF treatment, total exchangeable cation contents of yellow poplar was increased from $3.1g\;kg^{-1}$ to $4.4g\;kg^{-1}$, and as a result, biomass production of yellow poplar was also enhanced by 82.3%. Organosolv pretreatment was conducted with three independent variables: 1) reaction temperature: $133.2^{\circ}C$ to $166.8^{\circ}C$; 2) acid concentration: 0.2% to 1.8%; and 3) reaction time: 1.6 min to 18.4 min. Reaction temperature was the most significant variable in water insoluble solid (WIS) recovery rate. High overall sugar yield was attained from pretreatment conditions approximately 50% of WIS recovery rate, and the highest overall glucose yield (44.0%) was achieved from pretreatment at $140^{\circ}C$ with 1.5% acid concentration for 5 min. Consequently, 21.1% of glucose and 5.8% of xylose were produced from the organosolv pretreatment of SCBLF-treated 8-year-old yellow poplar.

• Applied Biological Chemistry
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• 제34권4호
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• pp.327-333
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• 1991

Cheddar치즈의 숙성기간을 단축시키고 flavor를 증진시킬 목적으로 단백분해력이 있는 Micrococcus sp. LL3를 Cheddar 치즈에 첨가하기 위하여 본 균의 최적배양을 위한 배지조성을 검토하였다. 탄소원으로는 glucose, mannose, fructose 등의 단당류가 양호하였으며, arabinose, xylose는 균의 성장을 심하게 저해하였다. 본 균주에서는 탄소원의 첨가에 의한 catabolite repression은 나타나지 않았다. 또한 질소원으로는 yeast extract 0.2%의 첨가가 균의 성장에 좋았으며, 무기 질소원 첨가시는 균의 성장이 감소하였다. 특히 urea를 첨가시 균의 성장에 심한 저해효과가 있었다. 본 균주는 NaCl 9%첨가시 까지도 균의 생육이 가능했으며, 특히 1%첨가시에는 균체생육 및 단백분해 효과가 다소 증가하였다. 무기염의 경우 $MgSO_4\;0.05%$, 아미노산은 glutamic acid 0.2%첨가시 효과가 좋았다. 그러나 비타민은 $0.1\;{\mu}g/ml$ 수준으로 첨가시에 균의 성장 및 단백분해 효과에 영향을 미치지 않았다.

• 한국식품과학회지
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• 제32권3호
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• pp.578-583
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• 2000

양파농축액의 제조시에 부산물로 생기는 양파착즙박을 이용하고자 건조양파착즙박 또는 건조양파를 옥분과 여러 농도(10, 20, 30%)로 혼합하여 쌍축압출성헝기를 이용하여 양파스낵을 제조하고 그 특성을 조사하였다. 양파착즙박은 건조양파보다 식이섬유소 함량이 약 2배 가량 높았고 lignin이 적은 식이섬유소였다. 갈변도는 양파의 첨가량이 증가할수록 높아졌다. 양파스낵의 환원당과 유리당은 양파의 첨가량이 많을수록 높게 나타났고 주된 유리당은 glucose와 fructose였다. 대조군 스낵의 flavonoid는 검출되지 않았고 양파박 스낵에는 quercetin과 관련배당체의 flavonoid 함량이 양파스낵과 비교할 때 약 50% 정도 존재하였다. 양파착즙박과 건조양파의 첨가량이 10%인 양파스낵의 경우 다른 농도의 처리구보다 관능검사결과 비교적 좋은 평가를 받았다.

• 한국축산식품학회지
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• 제34권6호
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• pp.769-776
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• 2014

The goat placenta was fermented by Bacillus subtilis and the optimal fermentation parameters of strongest antioxidant capacity of peptides were obtained using response surface methodology (RSM). The effects of fermentation time, initial pH value and glucose content on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the goat peptides were well fitted to a quadric equation with high determination coefficients. According to the data analysis of design expert, the strongest DPPH radical scavenging capacity value was obtained with the following conditions: content of glucose was 2.23%, initial pH value was 7.00 and fermentation time was 32.15 h. The DPPH radical scavenging capacity commonly referring antioxidant activity showed a concentration dependency and increased with increasing peptide concentration. The effects of temperature and pH were assessed to determine the stability of antioxidant peptides prepared from goat placenta. Antioxidant peptides showed good stabilities when temperature was lower than $70^{\circ}C$. However, the antioxidant peptides lost antioxidant activities rapidly under alkaline and excessive acid condition. Ultrafiltration technique was performed to separate fermentation broth with different Mw (molecular weight). It was found that peptides in the range of < 3 KDa mainly accounted for the antioxidant activities.

• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1210-1218
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• 2000

Four experiments were conducted to evaluate the effect of temperature and humidity on biochemical indices of Arbor Acres broilers at different weeks of age. The alkaline phosphatase (AKP), acid phosphatase (ACP), lactic dehydrogenase (LD), creatine kinase (CK), plasma glucose (Glu), calcium (Ca), potassium (K), chloride (Cl), urea nitrogen (UN), uric acid (UA), plasma thyroxin (T4), triiodothyronine (T3) and insulin levels were determined in all the four experiments. In experiment 1, the plasma Glu, LD and CK levels were increased by heat exposure ($35{^{\circ}C}$ and 35, 60, or 85% RH, 2 h) and this effect was aggravated by longer exposure (24 h). No significant changes (p>0.05) were found in Ca concentration, activity of AKP and ACP. In experiment 2, temperature (10, 20, 30, $33{^{\circ}C}$) had significant effect on the levels of K, Cl, UN, UA levels and the activity of LD (p<0.01), but had no significant influence on the activity of CK (p>0.05). The UN, UK and LD levels were elevated by low temperature $(10{^{\circ}C})$ (p<0.01), Cl content was increased by high temperature ($(33{^{\circ}C})$ (p<0.01), and K level was decreased by high ($(33{^{\circ}C})$ or low $(10{^{\circ}C})$ temperature and increased by medium temperature $(30{^{\circ}C})$ (p<0.01). The humidity (35, 85% RH) only had significant effect on Cl concentration which was decreased by high humidity (p<0.01). In experiment 3, the result showed that only the LD and CK activity were significantly increased (p<0.01) by high temperature (7, 24, 28, $32{^{\circ}C}$) or high humidity (35, 85% RH). Temperature and humidity had no significant effect on K, Cl, UA, UN and Glu levels (p>0.05). In experiment 4 (24, 27, 30, $33{^{\circ}C}$; 30, 45, 60, 75, 90% RH), plasma T3 level was declined by high temperature $(33{^{\circ}C})$, and this phenomena disappeared in birds under high temperature and high humidity environment. T4 concentration in plasma was not affected by temperature (p>0.05), but was increased by high or low humidity (p<0.01). Neither temperature nor humidity had significant effect on plasma insulin concentration (p>0.05). The results of the four experiments suggested that broilers at different growth periods might have different thermal requirements and would response differently to heat exposure. The plasma biochemical indices themselves had big variation; the reaction of the indices to thermal exposure treatment differed with the age of broilers. The big variation of biochemical indices themselves might cover the response of indices to temperature and humidity treatments.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1695-1702
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• 2009

An animal-component-free and chemically defined fed-batch process for GS-engineered cell lines producing recombinant antibodies has been developed. The fed-batch process relied on supplying sufficient nutrients to match their consumption, simultaneously minimizing the accumulation of by-products (lactate and osmolality). The proportionalities of nutritional consumption were determined by direct analysis. The robust, metabolically responsive feeding strategy was based on the offline measurement of glucose. The fed-batch process was shown to perform equivalently in GS-CHO and GS-NS0 cultures. Compared with batch cultures, the fed-batch technology generated the greater increase in cell yields (5-fold) and final antibody concentrations (4-8-fold). The majority of the increase in final antibody concentration was a function of the increased cell density and the prolonged culture time. This generic and high-yielding fed-batch process would shorten development time, and ensure process stability, thereby facilitating the manufacture of therapeutic antibodies by GS-engineered cell lines.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.48-53
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• 2006

The asymmetric biosynthesis of ethyl (S)-4-chloro-3-hydrobutanoate from ethyl 4-chloro-3-oxobutanoate was investigated by using whole cells of Candida magnoliae JX120-3 without the addition of glucose dehydrogenase or $NADP^+/NADPH$. In a one-phase system, the bioconversion yield was seriously affected on the addition of 12.1 g/L ethyl 4-chloro-3-oxobutanoate. In order to reduce this substrate inhibition, a water/ n-butyl acetate two-phase system was developed, and the bioreduction conditions optimized with regard to the yield and product enantiometric excess value. The optimal conditions were as following: water to n-butyl acetate volume ratio of 1:1, 4.0 g DCW/L active cells, 50 g/L glucose and $35^{\circ}C$. By adopting a dropwise substrate feeding strategy, high concentration of ethyl 4-chloro-3-oxobutanoate (60 g/L) could be asymmetrically reduced to ethyl (S)-4-chloro-3-hydrobutanoate with high yield (93.8%) and high enantiometric excess value (92.7%).