• KSBB Journal
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• 제18권2호
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• pp.145-148
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• 2003

P. aeruginosa F722는 탄화수소를 분해하는 과정에 biosurfactant (BS)를 생산한다. 탄화수소 분해에 사용되는 C-배지에서 BS 생산량은 0.78 g/ $\ell$이었으나, 질소원과 탄소원을 각각 0.05% (w/v) NH$_4$Cl + 0.1% (w/v) yeast extract과 3.0% (w/v) glucose로 조정한 경우는 BS 생산량이 1.66 g/ $\ell$로 증가하였다. 최적의 BS 생산조건으로 배양하는 동안 air 1.0 LPM를 공급해 주었을 때는 공기를 공급하지 않을 때의 1.66 g/ $\ell$보다 약 20% 증가한 1.94 g/ $\ell$이었다 뿐만 아니라, glucose 분해속도는 대수증식기와 정지기에서 air를 공급하지 않은 경우 0.25, 0.18 h$^{-1}$ 였으나, 공기를 1.0 LPM으로 공급한 경우 0.33, 0.29 h$^{-l}$ 로 조사되었다.

• KSBB Journal
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• 제8권2호
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• pp.156-163
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• 1993

Polyester 감량폐수의 주성분인 EG,TPA분해균을 분리하여 각각 Pseudomonas sp.로 동정하여 Pseudomonas sp. EAW, Pseudomonas sp. TS2로 명명하였다. 이 두 균주의 최적 배양조건은 pH 7.5, 온도 $35^{\circ}C$ 및 질소원은 ${(NH_4)}_2SO_4$ 이며, Strain EAW의 경우 niacin과 biotin, Strain TS2의 경우 $Na_2MoO_4{\cdot}2H_2O$와 thiamine이 각 균주의 성장과 분해율에 약간씩 영향을 미치는 것으로 나타났다. Strain EAW는 접종량의 증가에 따라서 성장 및 EG의 분해시간이 현저히 감소하였으나 Strain TS2의 경우는 접종량이 증가하여도 성장 및 분해율이 큰 차이가 없었다. 또한 rich-medium에 계대배양한 각 균을 EG, T TPA액체배지에 접종하였을 때 계대배양의 회수가 증가함에 따라 Strain EAW가 Strain TS2보다 성장 및 분해율이 현저히 감소하였다. 실제 폐수에서 균들의 성장 및 분해율이 분리용 배지의 경우 보다는 약간 감소하였으며 EG, TPA 는 배양 48hr 후 $COD_{Mn}\;and\;COD_{Cr}$의 제거율은 89% 와 93%로 각각 나타났다. 회분배양시 EG,TPA의 초기농도가 25g/L 이상에서는 각 균주의 비성장속도가 감소하였다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1995년도 식물학심포지움 식물로부터 유용 2차대사산물의 생산 PRODUCTION OF USEFUL SECONDARY METABOLITES FROM PLANTS
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• pp.67-78
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• 1995

Monoclonal antibodies (MoAbs) are a highly diversified class of proteins with major research and commercial applications such as diagnostics and therapeutics. Currently, the dominant method for producing MoAbs is through the hybridoma technique. However, this technique is slow, tedious, labor intensive, and expensive. The production of MoAbs in cultured transgenic plant cells can offer some advantages over that in the over that in the mammalian systems. The media to cultivate plant cells are well defined and inexpensive. Contamination by bacteria or fungi is easily monitored in plant tissue cultures. Furthermore, these contaminants are usually not potent pathogens to human beings. In our interdisciplinary research efforts, heavy chain monoclonal antibody (HC MAb) was inserted into Ti plasmid vector and transferred into A. tumefaciens for the transformation in tobacco cells. It was found that 76% of the transformants produced HC MAb. The presence of HC MAb in the cell membrane fraction indicated that the signal peptide was functional and efficient. The change of the HC MAb concentration during a batch culture followed a similar trend as dry cell concentration, indicating that the production of HC MAb was growth related. The long-term repeated subcultures of 11 cell lines showed that there was no obvious trend of neither the decrease nor the increase of the productivity with the repeated subcultures.

• KSBB Journal
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• 제18권2호
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• pp.149-154
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• 2003

수소를 생산하기 위하여 자연계로부터 분리된 균주는 Enterebacter cloacae로 동정되었으며 이 균주를 YJ-1으로 명명하였다. 수소발생량을 기준하여 이 균주의 최적 성장조건을 살펴본 바, 회분식 배양에서 $35^{\circ}C$, pH 7.5로 나타났다. 따라서 탄소원의 농도를 변화시킨 결과, 최대의 수소생산은 2% glucose, 4% sucrose, 5% fructose에서 각각 950 mL/L, 1000 mL/L, 948 mL/L을 얻어졌으며, 초기에 비해 2.5배 높은 생산량을 얻을 수 있었다. 유기산 축척에 따른 pH 저하를 막기 위해 완충제인 phosphate를 첨가한 결과, 50 mM에서 가장 높은 수소를 생산할 수 있었다. 반회분식 배양으로 50%의 새로운 배지를 8 hr 간격으로 치환하여 48시간동안 수행한 결과 1920 mL/L의 수소를 생산할 수 있었다. Yeast extract는 균체성장에 중요한 성분으로서 0.5%에서 최대의 수소를 생산할 수 있었다. 발효 중 생성된 유기산은 대부분 formic acid, acetic acid이고 적은 양의 propionic acid가 생성되었다.

• Fisheries and Aquatic Sciences
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• 제14권3호
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• pp.230-233
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• 2011

To determine the cost-effectiveness of converting fish waste into liquid fertilizer, this study analyzed the production of 3 L of liquid fertilizer from the fermentation of fish waste. The total product cost of the fertilizer was calculated to be $165.26 for a one-batch operation. If the seed culture was repeated five times, the total product cost could be reduced to $36.39/L. According to this analysis, the reutilization of fish waste as liquid fertilizer was not particularly economically attractive at present, and plant-scale production would be necessary for commercialization. This is the first cost-effectiveness analysis of the bioconversion of fish waste into liquid fertilizer.

• 한국미생물·생명공학회지
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• 제22권6호
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• pp.646-650
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• 1994

Aspergillus terreus NRRL 1960 was immobilized on various alginate gel beads, Celites, and polyurethane foam cubes, and the comparisons were made for the production of itaconic acid according to the types and sizes of each carrier. The levels of itaconic acid produced from Ca- alginate and Sr-alginate were similar, and the addition of bentonite to Ca- and Sr-alginate resulted in an increase of itaconic acid. The addition of 1.67% bentonite and 0.33% starch to Sr-alginate (SABS bead) produced higher level of itaconic acid (11.59 g/1) than other gel beads. A decrease in the size of Celite increased the itaconic acid production, and the smallest size of Celites, R- 634, produced 6.37 g/l of itaconic acid. Among various types of polyurethane foam cubes, HR 08 (2X2X2 cm) produced about 19 g/l of itaconic acid, which was more efficient than other carriers. In a repeated batch culture using immobilized cells on polyurethane foam cubes (HR 08, 2X2X2 cm), the stability of itaconic acid production was maintained up to 4 batches. Also, the possibility of itaconic acid production by continuous culture was shown in a packed-bed reactor.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.257-260
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• 2002

Dissolved oxygen level of cell culture media has a critical effect on cellular metabolism, which governs specific productivity of recombinant proteins and mammalian cell growth However, in the cores of cell aggregates or cell-immobilized beads, oxygen level frequently goes below a critical level. Mammalian cells have a number of genes induced in the lower level of oxygen, and the genes contain a common cis-acting element (-RCGTG-), hypoxia response element (HRE). By binding of hypoxia inducible factor-l (HIF-I) to the HRE, promoters of hypoxia inducible genes are activated, which is a survival mechanism. In this work, to develop a CHO cell capable of producing recombinant proteins in immobilization and high density cell culture efficiently, mammalian expression vectors containing human tissue-type plasminogen activator (t-PA) gene controlled by HRE were constructed and stably transfected into the CHO cells. In $Ba^{2+}$ -alginate immobilization culture, CHO/pCl/dhfr/2HRE-t-PA cells produced 2 folds higher recombinant t-PA activity than CHO/pCl/dhfrlt-PA cells without $CoCl_2$ treatment. Furthermore, in repeated fed batch culture, productivity of t-PA in immobilized CHO/pCI/dhfr/2HRE-t-PA cells was 121 ng/ml/day, total production of 0.968 mg/day at 11 days culture while CHO/pCIIdhfrlt-PA cells was 22.8 ng/ml/day. All these results indicate that HRE is very useful for the enhancement of protein productivity in mammalian cell cultures.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.400-406
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• 2012

To improve the hydrogen yield from biological fermentation of organic wastewater, a co-culture system of dark- and photo-fermentation bacteria was investigated. In a pure-culture system of the dark-fermentation bacterium Clostridium butyricum, a pH of 6.25 was found to be optimal, resulting in a hydrogen production rate of 18.7 ml-$H_2/l/h$. On the other hand, the photosynthetic bacterium Rhodobacter sphaeroides could produce the most hydrogen at 1.81mol-$H_2/mol$-glucose at pH 7.0. The maximum specific growth rate of R. sphaeroides was determined to be 2.93 $h^{-1}$ when acetic acid was used as the carbon source, a result that was significantly higher than that obtained using either glucose or a mixture of volatile fatty acids (VFAs). Acetic acid best supported R. sphaeroides cell growth but not hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag phase. There were distinguishable inflection points in a plot of accumulated hydrogen over time, resulting from the dynamic production or consumption of VFAs by the interaction between the dark- and photo-fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was 15.9 ml-$H_2/l/h$, which was achievable in a sustainable manner.

• 유기물자원화
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• 제11권1호
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• pp.70-76
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• 2003

소화슬러지를 열처리한 혼합 배양 미생물을 식종균으로, 자당을 기질로 사용하는 혐기성 수소 생산 공정을 운전하면서 pH 조절, 반복 열처리, 기질 농도 변화 등을 통해 지속적인 수소 생산 방법을 고찰하였다. 유입 기질의 농도가 5g COD/L인 경우 운전 초기에는 $0.5mole\;H_2/mole\;hexose$ 이상의 수소가 발생하지만 9일 이상 지속되지 못하였다. 이러한 현상의 원인은 수소 생성균이 공정 내에서 고농도로 존재하지 못하기 때문인 것으로 판단되며 pH를 5.3으로 유지하는 것만으로는 극복될 수 없었다. 반복 열처리를 적용할 경우 별도의 식종균 재주입 없이 효율이 감소된 수소 생성 공정을 원상태로 복구할 수 있음을 확인할 수 있었으나, 수소 생성 효율이 시간에 따라 감소하므로 열처리를 자주 해야 하는 문제가 발생했다. 유입 기질의 농도가 30g COD/L인 경우에는 24일간 지속적인 수소 생성이 가능하였으며, CSTR의 경우 $1.0-1.4mole\;H_2/mole\;hexose$, ASBR의 경우에는 $0.2-0.3mole\;H_2/mole\;hexose$의 생성 효율을 보였다. 수소 생성 시 유출수 내 용존성 유기물의 90% 이상은 유기산이었으며 그 중 n-butyrate가 가장 많은 양을 차지하였다.

• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.29-34
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• 2003

A Pseudomonas sp. strain NGK1 (NCIM 5120) capable of utilizing salicylate was immobilized in alginate and polyurethane foam (PUF). The degradation rate of salicylate by freely suspended cells was compared with the degradation rate by immobilized cells. In an initial 20 and 40 mM salicylate, free cells ($2{\times}10^{11}\;cfu\;ml^{-1}$) degraded to 16 and 14 mM, alginate-entrapped cells degraded to 18 and 26 mM, and PUF-entrapped cells degraded to 20 and 32 mM salicylate, respectively, in batch cultures. The alginate-and PUF-entrapped cells were used in repeated batch and continuous culture systems. The efficiency of both the immobilized systems f3r the degradation of salicylate was compared. It has been observed that the PUF-entrapped cells could be reused for more than 20 cycles whereas alginate-entrapped cells could be reused for a maximum of only 12 cycles, after which a decrease in degradation rat was observed with the initial 20 and 40 mM salicylate. The continuous degradation of sallcylate by freely suspended cells showed a negligible degradation rate of salicylate when compared with immobilized cells. With the immobilized cells in both alginate and polyurethane foam, the degradation rate increased with an increase in the dilution rate up to $2\;h^{-1}$ for 20 mM, and $1.5\;h^{-1}$ for 40 mM salicylate. The results revealed that PUF-entrapped cells were more efficient for the degradation of salicylate than alginate-entrapped cells and freely suspended cells.