한국생물공학회 2001년도 추계학술발표대회
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We showed the result that an appreciable difference of secondary structures in the intracrystlline protein was observed between Normal and Deform shells. In order to understand the exact secondary structure of proteins, we investigated the changes in protein conformation from the specific layers via Fourier Self-Deconvolution(FSD) techniques, using ATR(Attenuated Total Reflection) information.
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Suh, Suhk-Cheol;Lee, Seung-In;Lim, Myung-Ho;Lee, Si-Myung;Kim, Dong-Hern;Eun, Moo-Young;Kim, Ho-Il 53
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Previously we developed a CHO cell line (CHO-OTC1-A19) expressing the first two enzymes of urea cycle. This cell line showed higher ammonia removal activity and faster growth rate than the vector controlled CHO cells (CHO-neo-5). The purpose of this study was to develop a cell line with higher ammonia removal activity than the cell line developed previously. To accomplish this, we constructed stable CHO cell lines expressing the first three, the first four, or all five enzymes of urea cycle by the stable transfection method. We finally selected CHO-AL-19 cell line expressing the first three, the first four enzymes of the cycle with higher ammonia activity than CHO-OTC1-A19 and CHO-n대-5 cell lines: 40% and 15% higher than those of CHO-neo-5 and CHO-OTC1-A19 cell lines 72 hour after culture started, respectively. It also showed 44% and 10% higher cell viability than CHO-neo-5 and CHO- OTC1-A19 cell lines at higher cell density. In addition, CHO-AL-19 cells showed 45%-60% and about 20% lower ammonia concentration per cell than those of CHO-neo-% and CHO-OTC1-A19 cell lines, respectively. These results indicate that CHO-AL-19 could be used in the production of human therapeutic proteins with higher efficiency.
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Isopentenyl diphosphate (IPP) is the common, five-carbon building block in the biosynthesis of all isoprenoids. IPP in Escherichia coli is synthesized through the non-mevalonate pathway. The first reaction of IPP biosynthesis in E. coli is the formation of 1-deoxy-D-xylulose-5-phosphate(DXP), catalyzed by DXP synthase and encoded by dxs. The second reaction in the pathway is the reduction of DXP to 2-C-methyl-D-erythritol-4-phosphate, catalyzed by DXP reductoismerase and encoded by dxr. To determine if one of more of the reactions in the non-mevalonate pathway controlled flux to IPP, dxs and dxr were placed on several expression vectors under the control of three different promoters and transformed into three E. coli strains (
$DH5{\alpha}$ , XL1-Blue, and JM101) that had been engineered to produce lycopene, a kind of isoprenoids. Lycopene production was improved significantly in strains transformed with the dex expression vectors. At arabinose concentrations between 0 and 1.33 mM, cells expressiong both dxs and from$P_{BAD}$ on a midium-copy plasmid produced 1.4 -2.0 times more lycopene than cells expressing dxs only. However, at higher arabinose concentrations lycopene production in cell expressing both dxs and dxr was lower than in cells expression dxs only. A comparison of the three E. coli strains trasfomed with the arabinose-inducible dxs on a medium-copy plasmid revealed that lycopene production was highest in XL1-Blue. -
Groundwater, contaminated predominantly with aromatic compounds and chlorinated ethylene, could be biologically treated in a fluidized-bed reactor with immobilized cells. The decomposition efficiency for the aromatics was over 90% at the retention time of 2.5 h. The chlorinated ethylenes, especially trichloroethylene (TCE) and cis-dichloroethylene (DCE), could be decomposed only insufficiently. No anaerobic methane formation was observed for this groundwater even at a very low dissolved oxygen (DO) concentration of 0.75 mg/L. The variation of DO concentration resulted in an optimal value of 1.5 mg/L. The recycle of air waste could increase the utilization of oxygen. The amount of low boiling pollutants stripped out remained constant with the recycle, while for the higher boiling pollutants the stripping slightly increased. Using air instead of oxygen increases the flow rate of air waste, which is connected to a higher stripping of pollutants. In this investigation, the pollutant concentration in the air waste remained constant. The stripping of main pollutants did not exceed 0.3 %.
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A real time optimization algorithm for fed-batch cultures of recombinant yeast to determine the optimal substrate feed rate profile has been developed. Its development involved four key steps: (1) development of reliable adaptive model. (2) development of optimization algorithm. (3) design of on-line model update algorithm to be incorporated into the optimization algorithm and (4) experimental validation. A recombinant Saccharomyces cerevisiae producing human parathyroid hormone (hPTH) was chosen as the model strain. It was found to be very successful in maintaining cell growth and galactose consumption at leigh levels, thus resulting in significant improvements in the productivity (up to 2.1 times) and intact hPTH concentration (up to 1.5 times) compared with the case of an intermittent glucose and galactose, or galactose feeding.
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hGH 와 GST 절편으로 구성된 융합 단백질의 고정화 UK 칼럼에 의한 절단 반응 후 용출액의 pH를 3.5 로 낮춤으로써 이물질들을 침전시키고 이를 expanded bed chromatography 칼럼에 통과시킨 결과, 이물질들의 제거와 hGH 단량체의 흡착분리가 동시에 이루어겼다 . 흡착된 단량체는 NaCl 에 의해 용출되었으며 이 단계의 수율은 거의 100% 이었다 , 따라서 칼럼에 의한 절단 반응과 산 침전에 의한 이물질 침잔 반응 EBA 에 의한 이물질 제거 및 단량체 회수 반응을 연속적으로 진행할 수 있는 기초를 제시하였다 . 또한 고정화된 UK 는 guanidine HCl(6M)을 이용하여 unfolding 시키고 이를 세척하여 refolding 시킨 결과 20 회의 반복적인 처리 후에도 초기 활성의 약 80% 수준을 유지하였다. 이는 UK 가 공유결합된 상태에서 solid-phase refolding 이 가능하다는 증거이며, 고정화 효소 칼럼의 수영을 크게 향상시켜 경제성을 확보하는 방안으로 이용될 것으로 기대된다.
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Aspergillus niger has been used as a host system to express many heterologous proteins. It has various advantages over other expression systems in that it is a small eukaryotic GRAS (Generally Recognized aS Safe) organism with a capacity of secreting large amount of foreign proteins. However, it has been known that the presence of an abundant protease is a limiting factor to express a heterologous protein. The proteases deficient mutants of A. niger were obtained using UV -mutagenesis. A total of 1
${\times}$ $10^5$ spores were irradiated with 10-20% survival dose of UV, 600J/M2 at 280nm, and the resulting spores were screened on the casein -gelatin plates. Ten putative protease deficient mutants were further analyzed on the starch plates to differentiate the pro from the secretory mutant. An endogenous extracellular enzyme, glucose oxidase, was also examined to confirm that the mutant phenotype was due to the proteases deficiency rather than the mutation in the secretory pathway. The reduced proteolytic activity was measured using SDS-fibrin zymography gel, casein degradation assay, and bio-activity of a supplemented hGM -CSF (human Granulocyte-Macrophage Colony Stimulating Factor). Comparing with the wild type strain, less than 30 % of proteolytic activity was observed in the culture filtrate of the protease deficient mutant (pro -20) without any notable changes in cell growth and secretion. -
80여일 운전 후 수분함량은 상부 (53%) 보다 하부 (66%) 가 다소 높게 나왔다. 34 일의 적응기가 나타났으며 34일 경과 후 VOC의 분해율은 90% 에 이르렀다. 총 세균수 측정 결과, 37일 운전 후 총개체수는
$25^{\circ}C$ 에서$1.08{\times}10^8$ cells/g 로 최고치를 기록하였다. 9가지 휘발성 유기화합물의 성분별 제거는 isoprene($95{\sim}99%$ )과 m-xylene (93%)의 제거율이 가장 높았으며, chloroform (62%)이 가장 낮은 제거율을 보였다. -
The effect of stabilizing polymer on hGM-CSF production was investigated in suspension cell cultures of transgenic tobacco. Secreted human GM -CSF from cell suspension cultures was detected in the medium at a maximum concentration of 180
${\mu}g/L$ by ELISA. However, the secreted hGM -CSF was unstable in the medium, and rapidly degraded after day 5. In order to stabilize the secreted hGM-CSF, three stabilizing polymers were tested, polyethylene glycol, polyvinylpyrrolidone and gelatin. Gelatin was the most effective in stabilizing the secreted GM-CSF. Following the addition of 5% (w/v) gelatin, the maximum GM -CSF concentration reached 783${\mu}g/L$ , a 4.6-fold increase over control. -
본 연구에서는 히루딘을 생산할 수 있는 재조합 S. cerevisiae 에서 ‘히루딘 유전자의 copy number 와 히루딘 발현양과의 관계를 규명하였으며 ,
${\delta}$ 서열을 이중으로 사용한 히루딘 발현벡터를 제조하여 히루딘 유전자의 효모염색체로의 도입효율을 증가시켰다. 숙주세포인 효모의 GALl 유전자를 파쇄하여 균체에 의한 갈락토스 소모를 방지하여 보다 경제적으로 히루딘을 생산할 수 있는 시스템을 개발하였으며, 재조합 H. polymorpha을 이용한 발효공정에서 히루딘 생산을 위한 최적의 메탄올 농도를 결정하였다. -
Bioluminescent bacteria fusing the stress promoter and lux gene have been developed as a toxicity biosensor. The light emitting bioluminescent bacteria have been used to measure the toxicity of many different chemicals. In this study, specially, DPD2540 (fabA::luxCDABE) was used to detect and classify phenolic toxicity to the cells membrane fatty acids, and then the relationship between phenolic toxicity and the distribution of various phenols in the cell was determined, with a model and equations provided. In addition, to show the possibility of detecting and classifying the toxicity of a chemical mixture, which may be present in wastewater, various bioluminescent bacteria having different stress promoters were used and their distinct response to the sample mixture was measured. To extend the applicable area of these bioluminescent bacteria to field, the portable biosensor using freeze-drying methods was developed and confirmed successfully.
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Among the tested ten enzymes, Optimase M-440 showed the highest activity in transesterification of N-t-Boc-L-Phe-OTFE with D-glucose. Monosaccharides and their derivatives acted as good acyl acceptors in the Optimase M -440 catalyzed transesterification of N-t-Boc-L-Phe-OTFE. Optimase M-440 showed a preferable catalytic activity on the primary hydroxyl group of saccharides and a good regioselectivity. Optimase M-440 showed the highest activity in pyricline among the tested solvents. As acyl donors, trifluoroethyl esters of amino acids showed a high reactivity in transesterification. Optimase M-440 showed a broad substrate specificity towards amin 。 acid esters and saccharides.
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최근 인간 유전체 사업(Human Genome Project)의 완성과 DNA Microarray, Proteomics, Bioinformatics 등의 초고속, 대용량 처리 바이오기술 (High Throughput Biotechnology)의 발전과 함께 생명과학 분야의 연구는 획기적인 변화의 시기를 맞이하게 되었다. 이미 의약품 분야는 이러한 기술을 활용한 연구가 보편화 되어있고 선진 외국 회사들의 화장품연구 또한 이를 활용한 연구가 본격화 되고 있다. 화장품개발에 있어서도 이러한 기술들의 활용이 불가피하게 되었다 . 여기서는 이러한 새로운 바이오기술들에 관해 간단히 알아보고 향후 이러한 기술들의 효과적인 화장품개발 관련연구 활용범위와 활용방법에 대하여 알아본다.
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산삼은 고유의 생약으로 민간 또는 한방에서 효능을 인정받아 왔으나 산삼의 희귀성으로 인하여 산삼에 대한 연구가 활발하지 못하였다. 따라서 본 실험은 식물 조직 배양 기술을 이용하여 산삼 부정근을 대량으로 배양하고 추출하여 화장품 원료로서의 적용 가능성을 연구하였다.
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Tobacco plants were transformed by A. tumefaciens harboring human ferritin gene and they were subjected to investigate for the expression of transformed gene as well as heavy metal accumulation. Seed from self-fertilized transgenic plants was germinated on media containing toxic level of Cd, Cu, Zn, Fe, Mn and scored for tolerance to this heavy metals. There is difference in growth rate between transgenic and control plants, especially Cd, Cu. And transgenic plants accumulated more heavy metals than control plants.
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The biological fixation of carbon dioxide using microalgae have many advantages over chemicals and remove carbon dioxide simultaneously. A ketocarotenoid astaxanthin is hyper-accumulated in the green freshwater microalga, Haematococcus pluvialis. In the present study, the combine effects of carbon dioxide concentration and light intensity on the growth of H. pluvilais were investigated. The carbon dioxide concentration above 10% caused a severe inhibition and around 5% is optimal for growth. Adaptation to high concentration of carbon dioxide enhanced the
$CO_2$ tolerance. Specific growth rate calculated differently based upon cell number or dry weight because of the distinctive life cycle patterns of H. pluvialis : small-sized motile green cell and thick cell walled red cyst cell. Based on the light dependence of H. pluvialis, internally illuminated air-lift photobioreactor was designed and operated. Gradual increase of light supply gave more active growth and more effective productivity of astaxanthin than constant light supply. -
We have developed a synthetic method for dTDP-4-keto-6-deoxy-D-glucose with four enzyme system. We have used crude extracts from cultures of Escherichia coli BL21 strains harboring plasmids containing different sources. dTDP-4-keto-6-deoxy-D-glucose was synthesized by the combination of thymidine-monophosphate kinase, acetate kinase, dTDP-glucose synthase and dTDP-D-glucose 4,6-dehydratase in a batch system, starting the reaction with dTMP. The enzymatic synthesis strategy allowed a dTMP conversion with a 95%.
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Polyamine 함량이 증가된 형질전환 식물체들은
$H_2O_2$ 처리에 의해서 야기된 산화적스트레스에 대해 야생형 식물체보다 조직 손상이 월등히 낮았으며 백화와 괴사되는 정도도 훨씬 낮았으며 chlorophyll 양의 손실도 비교적 적은 편이었다. 또한 고염분 스트레스를 처리하면서 야생형보다 비교적 높게 유지되었으며 4달 정도까지 생장이 지속되었지만 야생형 식물체에서는 생장이 거의 정지되어 식물체가 고사하였다. 그 외에 ABA를 처리하여 노화를 유도한 경우 야생형에서 훨씬 빠르게 노화가 일어났으며 형질전환 식물체 잎에서는 노화가 트게 지연되었다. 또한 pH3.0의 potassium phosphate를 처리한 경우에도 야생형의 잎보다 형질전환 식물체 잎에서 갈변등의 세포 손상이 크게 지연되었다. 곰팡이 감염에서도 높은 저항성을 보였으며 항산화효소임 GST와 CAT 유전자 발현이 증가하였다. Ethylene 발현 저해 식물체에서도 스트레스를 처리한 후 ethylene 생합성 효소의 발현이 억제되면서 스트레스 저항성을 나타내었다. 따라서 이러한 스트레스에 의하여 유도되는 노화의 지연현상이 야생형 식물체보다 형질전환 식물체 잎에서 두드러지게 나타나는데 그 기작은 mpolyamine이 이러한 스트레스를 완화시키는데 작용하였기 때문이라고 생각된다. -
IL-18. formerly known as IGIF(interferon -gamma inducing factor), is structurally IL-l related but functionally IL-12 related pro-inflammatory cytokine. The human IL -18(hIL-lS), like IL-
$1{\beta}$ , is synthesized as a biologically inactive precursor of 24kDa lacking a signal peptide, and then cleaved into an active mature form by cystein protease IL-$1{\beta}$ converting enzyme (ICE: caspase- 1), We tested if the mature hIL -18 can be expressed and secreted into culture medium by transforming the forming gene construct consisting of a mature hIL-18 gene fused to signal peptide of rice amylase lA. Secondly, we were tested if the pro- IL-18 could be processed into a biologically active form by caspase-l like protease in plant. Cell suspension culture was established from the leaf-derived calli of transgenic tobacco plant. Southern and Northern blot analysis indicated the expression of both pro-hIL-18 and mature hIL-18 plant cells. Western blot analysis introduced the protein products of pro- hIL -18 and mhIL -18 were observed in transigenic cell lines. In addition, the molecular size of recombinant pro-hILl-18 and mhIL-18 were estimated to be 24kDa and 18kDa, respectively. ELISA revealed that the amount of pro- hIL -18 was 1.3ug per gram of fresh weight calli. Moreover, the presence of mhIL-18 was detected in the culture medium and it appeared to be 25ug/L. -
A fusion protein, consisting of human epidermal growth factor as a recognition domain and human angiogenin as a toxin domain, can be used as a targeted therapeutic against breast cancer cells among others. The fusion protein was expressed as inclusion body in recombinant E. coli, and when the conventional, solution-phase refolding process was used the refolding yield was very low due to severe aggregation, probably due to the opposite surface charge due to vastly different pI values of each domain. Solid-phase refolding process exploiting ionic interactions between the solid matrix and the protein was tried, but the ionic binding yield was very low regardless of the resins and pH conditions used. To provide higher affinity toward the solid matrix, six lysine residues were tagged to the N -terminus of the hEGF domain When the cation exchange resins such as heparin- or CM-Sepharose were used as the matrix, the adsorption capacity increased 2.5-3 times and the subsequent refolding yield increased nearly IS times compared to the conventional process.
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본 실험에서는 우유에 존재하는 특정미생물을 PCR 에 의해 검출하기 위한 시료 전처리 방법을 비교 하였다 . PCR 혼합물 내에 우유의 함량이 높아지면 PCR이 저해됨을 알 수 있으며 SDS lysis 처리를 한 후의 PCR 효율이 가장 좋았다.
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Recombinant human GM -CSF was expressed and secreted from transgenic rice cell suspension cultures in its biologically active form. This was accomplished by transforming rice callus tissues with an expression vector, pMYN44. containing the hGM -CSF cDNA. Regulated expression and secretion of hGM -CSF from this vector achieved using the promoter, signal peptide, and terminator from a rice alfa-amylase gene Amy3D. The Amy3D gene is expressed in response to sugar deprivation. The recombinant hGM -CSF was expressed from the transgenic rice cell culture on the sugar-free medium as a yield of about 110 mg/L in the culture filtrate, which was determined by ELISA. Biological activity of hGM-CSF was confirmed by measuring the proliferation of the hGM -CSF dependent TF -1 cells.(This work was supported by a grant from the NRL program of the Korean Ministry of Science and Technology. Shin, Y.- J.. Lee. J.-H and Kwon, T.-H. have been supported by BK21 program from the Korean Ministry of Education)
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GlcNAc 2-epimerase gene from human was cloned. However GIcNAc 2-epimerase was expressed in E. coli as inclusion body formation. Several approaches were tried such as expression in low temperature and low concentration of IPTG. With these treatments production of active form of human GIcNAc 2-epimerase ι ,vas enhanced. For the direct synthesis of NeuAc from GlcNAc and pyruvate, NALase and GlcNAc 2-epimerase were characterized in terms of temperature effect on activity. equilibrium and stability, inhibition by pyruvate etc. For cheap and ease preparation of both the NALase and GlcNAc 2-epimerase, pEN24ma vector was made. which express both the NALasc and GIcNAc 2-epimerase simultaneously. In addition, E. coli BL21(DE3) harboring two plasmids was also made. Of the two systems, the latter was better for the expression of both enzymes.
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Mouse monoclonal antibody(mAb) with an antigen specificity for major histocompatibility complex class Il(MHC class II) was produced and secreted from tobacco cell suspension culture by successive sexual crossesu. Expression and secretion of assembled antibody was observed in transgenic tobacco cell suspension culture by wetern blot analysis.
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Enzyme production of calcium stearate was attempted by lipase, hydrogenated beef tallow that contain high level of stearic acid was used by substrate. 90% of hydrogenated beef tallow was converted into calcium stearate in 2.5hr. Calcium stearate that was produced by this method was purified and recovered through new method and this purified and recovered calcium stearate was compared with standard calcium stearate through FT- IR. This result showed the possible replacement of conventional process into enzymetic reaction process.
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Effect of hyperosmotic pressure on growth of recombinant Chinese hamster 。 vary cells and Erythropoietin (EPO) production was investigated. Cells were cultivated in batch modes at various osmolalities. When the osmolality increased from 314 to 463mOsm/Kg, specific EPO productivity (qp) was increased up to 1.6-fold but cell growth was inhibited. EPO has a complex oligosaccharide structure that plays an important role in biological activity in vivo. To investigate the influence of hypoerosmotic pressure on the glycosylation, structural analysis of oligosaccharide was calTied out. Recombinant human EPO was produced by CHO cells grown under various osmotic pressure and purified from culture supernatants by heparin-sepharose affinity column and immunoaffinity column. N-linked oligosaccharides were released enzymatically and isolated by paper chromatography. The isolated oligosaccharides were labeled with fluorescent dye, 2-aminobenzamide and analyzed with MonoQ anion exchange chromatography and GlycosepN amide chromatography for the assignment of GU (glucose unit) value. Glycan analysis by HPLC showed that neutral (asialo) oligosaccharide was increased slightly with an increase in osmolality. In portion of sialylated glycan, total relative amount of mono- and di-sialyated glycan was increased but that of tri- and tetra-sialylated glycan decreased as osmolality was increased.
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RhRnBp and Peysn5 are the proteins related to carbohydrate synthesis. RhRnBp originated form human was expressed as inclusion body in E. coli. Peysn5 originated form actinomadura was expressed as low level and inclusion body in E. coli. Ub, Trx, MalE and NusA is used as fusion partner to RhRnBp and Peysn5. The solubility of all fusion protein is NusA > MalE> Trx > Ub. Expression level of RhRnBp fusions in
$37^{\circ}C$ is higher than that in$25^{\circ}C$ . However in the case of Peysn5. Expression levels in$25^{\circ}C$ were higher. MalE fusion had highest activity in RhRnBp fusions. There were no activity in Peysn5. -
We produced human IL-12, which is consisted of p35 and p40 subunits through tobacco cell suspension culture. In batch culture, the maximum hIL -12 production of 180.5
${\mu}g/L$ was obtained in 5days after inoculation. The effect of gelatin on the production of hIL-12 was also tested. -
Biacore 바이오센서를 이용하여 재조합 HBsAg 를 정량분석하기 위해 CM5 칩 위에 anti-HBsAg polyclonal antibody를 저밀도 (2,304.2 RU)와 고밀도(17635.9 RU)로 고정화한 후 다양한 농도의 HBsAg를 흘려주어 각 농도별 sensorgram을 얻었다. 각 sensorgram으로부터 결합된 HBsAg의 질량을 구하여 액체 시료 내의 HBsAg의 농도 대 칩에 결합된 HBsAg의 질량 사이의 상관관계를 구한 결과 Langmuir 단일층 흡착 등온선과 매우 유사한 형태의 calibration curve를 얻었다. 약 40
${\mu}g/m{\ell}$ 까지 선형 관계가 유지되었다. 이 calibration curve를 double-reciprocal plotting 하여$RU_{max}$ 값을 각각 구한 뒤, 단위 질량의 고정화된 항체 당 결합된 HBsAg의 질량을 구한 결과 저밀도 칩에서 0.024, 고밀도 칩에서 0.023 으로 매우 유사한 결과를 나타내었다. -
유전자 분석 기술은 biomedical analysis를 위해 일반적으로 고체 상에 고정화된 DNA 분자를 이용한다. 이 센서의 검출능력은 주로 capture probe의 서열뿐만 아니라 oligonucleotide의 고체 상에 고정화 방법에 달려있다. 본 연구에서는 glass 표면에 DNA 분자를 고정화시키는 방법과 PCR product를 정제하지 않고 직접 검출할 수 있는 DNA probe assay 방법을 개발하였다.
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On-line monitoring technique for the concentration of lactate by a FIA(Flow Injection Analysis) system was studied. The lactate oxidase(LOD) was immboilized on VA-Epoxy carrier and integrated into the FIA system. The pH, buffer flow rate and temperature for the LOD-FIA were optimized, and the effects of salts and metabolites dissolved in the sample on the activity of immobilized enzyme were investigated. The LOD-FIA has been applied to monitor the concentrations of lactate in a simulated bioprocess. The on-line monitoring data by the LOD-FIA agreed with the off-line data measured by a fluorescence spectroscopy well.
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본 연구에서는 섬유상담체가 설치된 고정화 생촉매 air-lift bioreactor를 개발하여 HDS(hydrodesulfuriza tion)를 거친 디젤유를 대상으로 고심도 탈황을 시도하였다. 생촉매의 활성유지와 세포성장에 필요한 탄소원으로는 glucose보다 sucrose가 더 유리한 것으로 나타났다. 반복회분탈황반응을 통하여 약 60 시간 만에 디젤 중 황함량이 550ppm 에서 50ppm 이하로 감소되었다.
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본 연구에서는 축산폐수를 이용하여 건조질량의
$15{\sim}75$ %의 탄화수소를 생산한다고 알려진 B. braunii 배양에 적용하였다. 질소원이 부족한 상황에서 세포의 성장이 나 탄화수소의 생산은 저해를 받았으며, 초기 인의 농도는 질소원이 결핍된 상황을 제외하고는 세포 성장이나 탄화수소의 생산에 큰 영향을 미치지 못했다. 축산폐수를 이용한 설험에서는 33 %의 축산폐수가 nitrate를 제거시키는데 가장 적절하였다. -
Toluene으로
$30{\sim}60$ 분 스트레스를 주어 5회 이상 단백질의 pattern을 조사한 결과, toluene과 heat에 의해서$3{\sim}5$ 개정도의 단백질이 중복되게 발현됨을 알 수 있었다. 일반적으로 10kDa 이하의 단백질들은 transcription factor로서 작용하는 것으로 보고되고 있는데, 본 실험에서는 약 7kDa인 단백질이 유기용매에 의해서 유도됨이 확인되었으며,$30{\sim}45$ 분에서 단백질 발현율이 2 배 이상 증가하였다. -
Choi, Seung-Tae;Kim, Soon-Jeong;Lee, Kyung;Moon, Ja-Young;Kim, Dong-Wan;Lee, Ho-Won;Seo, Jeoung-Yoon;Hwang, Choi-Won;Jeong, Young-Kee;Joo, Woo-Hong 257
유기용매 내성 균주를 분리하기 위해서 석유화학 공업단지 부근의 폐수 및 토양을 채취하여 각종 유기용매에 적응시킨 후 순수 분리를 통하여 내성을 가진 균주를 분리하였으며 그 중에 서 가장 내성이 강한 균주 BCND 106, 154 and 171 을 분리하였다. 이 균주를 이용하여 유기용매 내성 및 분해능 검사를 하였다. 그 결과 이 세 균주는 본 실험에 사용한 유기용매 대부분에 대해서 내성을 나타내었으며, 또한 이를 탄소원으로도 이용하였다. 특히 BCNU 106 과 171 은 xylene isomer 인 meta-, para-xylene을 탄소원으로 이용할 뿐아니라 특히 독성이 강한 것으로 알려져 있는 ortho-xylene도 동시에 분해하는 것으로 알 수 있었다. 또한 항생제와 중금속에 대해서도 강한 내성을 나타내었는데, 이는 유기용매 내성 기작과 밀집한 관련이 있는 것으로 판단한다. -
점안약에 광범위하게 사용되는 보존제(preservatives)의 세포독성 및 항균활성 및 항진균 활성을 검정하였다. 세포독성은 L929 세포를 사용하였으며, 항균항진균 활성검정에 사용된 균주는 Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923 등 2가지이고, 진균은 Trichoderma reesei A TCC6967을 사용하였다. 사용된 시약은 합성보존제인 benzalkoniumchloride(BAK)와 천연보존제인 키토산이며 키토산의 분자량은 60,000, 탈아세틸화도는 95%, 점도는 2cps였다. L929 세포에 대해 24hr, 48hr, 72hr에 대해 각각 농도에 따른 세포독성검정 결과 세포의 30% 이상 성장저해를 일으키는 농도는 BAK의 경우 0.001%였고, 키토산의 경우는 0.6%였으며 이 결과는 시간에 따라 유의성 있는 변화가 없었다. 각 각의 균에 대한 BAK 의 항균항진균 활성을 나타내는 최소저해농도는 P.aeruginosa에는 0.1%였고, S. aureus에는 0.001 %였으며 T reesel'에는 0.1%였다. 키토산은 P. aeruginosa의 경우 2%, S. aureus가 1%에서 2일간 정균작용을 나타내었다. 진균에 대해서는 농도 의존적으로 생육을 촉진시켰다. 천연보존제는 합성보존제에 비해 독성을 일으키지 않으며 약리작용이 있는 반면에 항균성이 떨어지므로 이에 대한 연구가 더 필요하다.
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Solubilized silk fibroin by salt can be further processed by dialysis. The solution was dialyzed by continuous distilled water. The dialysis kinetics of silk fibroin was investigated.
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The fluorescence sensor is utilized to monitor the complex fluorescence patterns of intra- and extracellular components in cultivation processes. Especially biogenic fluorophores such as proteins and peptides (tryptophan, phenylalanine), coenzymes (FAD, NAD(P)H) and vitamins (riboflavin, pyridoxine) within cells are detected by a fluorescence sensor. In this work a 2-dimensional fluorescence sensor has been used to monitor a production process of itaconic acid by Aspergillus terreus and the on-line monitored spectra data can be con-elated to off-line data measured by a few methods.
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미생물에 독성영향을 미치는 것으로 알려진 SCN 이 포항제철소내 관리형 매립시설에서 나오는 침출수에 함유된 농도는 미생물에 의해 제거될 수 있었다. 온도에 따른 SBR 운전 결과를 통하여 적응된 이후에 비해서 초기에 긴 적응기간이 필요하다. 온도가 증가함에 따라 초기 직응기간이 짧아지고 수렴하는 SCN 제거소요시간이 짧아짐을 알 수 있었다.
$SCN^-$ 이 미생물의 애너지원과 질소, 황, 탄소원으로 사용되어 제거됨을 온도변화에 따른 SBR 운전으로 알 수 있었다. -
A fixed bed biofilm reactor filled with ceramic media were used to remove nitrogen by selective nitrification (ammonium to nitrite). The effects of experimental conditions (nitrogen load, dissolved oxygen, nitrite ratio, C/N ratio) on denitrification were investigated. The reactor showed more than 80% average T-N removal efficiencies at T-N loading in the range of
$1.1{\sim}3.3$ kg$T-N/m^3{\cdot}d$ C/N at the C/N ratio of 1. T-N removal efficiencies increased as nitrite ratio. -
질산화 생물여과 시스템 내 생물막 안에 존재하는 ammonia oxidizers 및 nitrite oxidizers의 군집 구조 및 공간적 분포를 조사하였다. FISH 분석 결과 생물막 내 숫적으로 우점종을 이루는 미생물은 ammonia oxidizer인 Nitrosomonas spp.로 나타났으며 nitrite oxidizer 인 Nilrospira spp.에 비해 3
${\sim}$ 5 정도 더 많이 존재하였다. 이는 실협 기간동안 완전한 질산화를 보였지만 반응기가 2 년 이상 nitrite 축적을 위해 높은 free ammonia 농도 빛 낮은 용존 산소 상태에서 운선되어 nitrite oxidizers에 저해를 주었기 때문인 것으로 사료된다. FISH와 결합된 CLSM 관찰 결과 생물막 전체에 걸쳐 ammonia oxidizer가 분포하는 반면 안쪽으로 갈수록 nitrite oxidizers가 분포함을 보였다. 이는 폐수의 ammonium 을 생물막 내 ammon ia oxidizer가 먼저 nitrite로 산화시키고 이를 nitrite oxidizers가 곧바로 nitrate로 산화시키기 때문이다. -
Anaerobic ammonium oxidation with nitrite to
$N_2$ (anammox) is a recently discovered microbial reaction with interesting potential for nitrogen removal from wastewater. Here we investigated the microbial community structure in the sequencing batch reactor(SBR) with an anammox activity. The SBR was optimized for the enrichment of a very slowly growing microbial community and showed that possibility of anaerobic ammonium oxidation. Fluorescence in situ hybridization(FISH) analysis revealed that anaerobic ammonium oxidizers were Candidatus Brocadia anammoxidans and Candidatus Kuenenia stuttgartiensis. Furthermore, Nitrosomol1as spp. of the${\beta}$ -subclass of Proteobacteria was also present within the anaerobic SBR microorganisms. -
본 연구는 Bacillus sp.의 고농도 생산을 위한 최적배지 조건의 확립과 배양중 발생하는 foam control에 대해 알아보았다. PBD와 “one factor at a time", BBD로 이여지는 배지 최적화 과정을 통해 최초 생산 배지에서의 균체량보다 100% 이상의 향상된 균사체량을 볼 수 있었다. 또한 scale-up 과정에서 발생하는 foam control를 위해 각기 다른 type의 antifoam을 사용하였는데, 적당한 농도에서 좋은 생장을 보이고 있었고, vegetable oil은 foam control과 값비싼 탄소원인 soluble starch을 대신할 수 있는 좋은 기질임을 알 수 있었다. 또한 배양액 내의 산소를 잡고 있으면서 좋은 전달자의 역학을 하여 급격한 DO의 감소를 막아주었다.
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Sophorolipid, a biosurfactant produced from Candida bombicola ATCC 22214. showed antimicrobial activity against Bacillus subtilis. Staphylococcus xylosus, Streptococcus mutans, and Propionibacterium acne at 4, 1, 1, 0.5 ppm as MIC(minimum inhibitory concentration). Also 100ppm of sophorolipid inhibited 50% of cell growth of plant pathogenic fungus. Botrytis cinerea. However, sophorolipid showed no effect on the Escherichia coli, indicating its selective antimicrobial activity depending on the cell wall structure. Treatment of B. subtilis with sophorolipid increased the leakage of intracellular enzyme, malate dehydrogenase, indicating the possible interaction of sophorolipid with cellular membrane. Between lactone-type and acid-type sophorolipid, the former showed higher antimicrobial activity.
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본 실험의 결과, H. pluvialis의 배양에 있어서 고농도의
$CO_2$ 를 공급함으로서 세포의 성장속도가 의미 있게 증가함을 알았고, 더불어$CO_2$ 가 공급되는 경우, acatate 와 같은 유기탄소원이 오히려 세포의 성장을 저해함을 알 수 있었다. -
반응표면분석법을 이용하여 우지의 고온, 고압가수분해 공정조건을 최적화 시키고자 하였다. 이때 선정된 공정의 독립변수로는 반응온도, 반응압력 그리고 fat/water ratio이었으며 이에 대한 중속변수로는 TG, FFA, 1,3-DG, 2,3-DG 그리고 MG을 선정하였다. 반응압력을 이산화탄소를 이용하여 가수분해반응속도를 증가시키고자 하였지만 지방산 생성농도에는 커다란 영향을 미치지는 않았다. 지방산 생성농도에 대해서는 다른 공정변수들에 비해 반응온도에 크게 의존하였고, Derringer-Suich 방법을 이용한 지방산 생성농도를 최적화 시킬 수 있는 조건으로는 반응온도
$271^{\circ}C$ 반응압력 86 bar 그리고 far/water ratio 106.08g/133.92g를 얻었으며 이 조건에서 3시간동안 가수분해하여 얻은 FFA생성농도는 96.49%로 얻었다. 통계적 분석에 이용된 자료들은 유의성 검증, 적합결여, 그리고 잔차분석 등을 해석한 결과 모든 자료가 95%이상의 신뢰도를 가지므로 매우 유익한 것으로 사료된다. -
10%의 아카시아꽃을 함유한 덧밥에 누룩을 15% 첨가하고 Saccharomyces cerevisiae를 이용하여 제조한 주모를 첨가한 후
$25^{\circ}C$ 에서 20일간 발효시켰을 때 에탄올이 가장 많이 생성되었다. 또한, 기호도와 색상은 아카시아꽃 15% 첨가하여 제조한 발효주가 가장 좋았고 전자공여능과 아질산염 제거활성이 무첨가 발효주 보다 강하였다. -
In this study various nutritional and environmental parameters such as, initial moisture content, pH. inoculum size, air rate, sample size and nutrient supplement that influence pigment production were evaluated in solid-state cultures. optimum initial moisture content and pH were determined to be 50% and 6.0, respectively. The supplement of the substrate with different carbon, nitrogen, and mineral source reveals a more inhibitive effect as the substrate concentration increase. optimum aeration rate was determined to be 2vvm in flask culture. The maximum amount of red pigment, 3500 OD/g dried fermented rice, was obtained in optimum conditions which is obtained in solid flask culture.
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R. eutropha 의 PHA 생합성 유전자를 포함하는 플라스미드 pSYLl07을 가진 재조합 대장균 GCSC6576 과 A. latus PHA 생합성 유전자를 포함하는 플라스미드 pJC4 한 가진 fadR atoC 돌연변이주 재조합 대장균 LS5218 의 유청으로부터 P(3HB- co -3HV) 합성을 비교하였다. 재조합 대장균 LS5218의 pH-stat 유가식 배양결괴 39 시간에 균체농도 31.8 g/L. P(3HB-co-3HV) 농도 10.6 g/L. P(3HB-co-3HV) 함량 33.4 wt%. 3HV 함량 6.26 mol%를 얻을 수 있었다.
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Teicoplanin is a glycopeptide antibiotic produced by Actinoplanes teichomyceticus novo sp. A TCC 31121. It is active against Gram-positive bacteria and it is under evaluation for use in man. Teicoplanin mixture in fermentation broth contains major amounts of teicoplanin
$A_1$ and$A_2$ and a minor amount tcicoplanin of$A_3$ . Commercial teicoplanin product is composed of five major components of very similar polarity, designated T-$A_2$ -l, 2, 3, 4 and 5, and the more polor component, designated T -$A_3$ . The culture conditions were studied in order that hydrophilic teicoplanin$A_2$ components are more produced but hydrophobic teicoplanin$A_1$ with lower bioactivity are less produced in submerged culture. Effects of culture pH and nutrients on the biosynthes ratio of teicoplanin$A_1$ and$A_2$ were confirmed in flask culture using MOPS buffer system through TLC, bioautography and bioassay. It was elucidated that optimal pH is 7.4 for teicoplanin$A_2$ biosynthesis but is 5.2 for teicoplanin$A_1$ biosynthesis, and that trace elements stimulate$A_2$ production but malt extract stimulate$A_1$ production. -
적색 색소를 생성하는 곰팡이 RF10l 로부터 여러 용매를 이용하여 추출물을 얻어낸 후 각 추출물의 특성을 조사한 결과 chloroform 용액은 510nm 에서 흡수 peak를 나타냈으며, pH 5-9 영역에서 안정함을 보였고, 암상태의 저온과 실온에서 5 일이 경과 한 후90% 이상이 구조적으로 안정함을 보였다. 금속이온들 중 NaCl을 제외하고 KCl.
$CaCl_2$ ,$MgCl_2$ 용액에서 5 일이 경과한 후에도 60% 이상의 안정함을 나타내었고, 균사체 powder 가 0.5% 첨가된 배지에서는 모든 균주의 생장이 억제되었으며 70% methanol 추출물 .$70^{\circ}C$ D.W 추출물에서도 생장억제 효과가 크게 나타났다. 이러한 결과로 볼 때, 더 많은 연구가 진행된다면 곰팡이 RFl0l로부터 산업적 이용 가치가 있는 물질을 생산할 수 있을 깃으로 생각되며 그에 대한 연구는 계속 수행중에 있다. -
A simple control strategy of DO-stat was introduced to the recombinant rGuamerin production process in Pichia pastoris. This induction strategy consisted of two interrelated control loops ‘by which oxygen ratio of inlet gas and methanol feeding rate was controlled. Using this control strategy, over-feeding or under-feeding of methanol could be avoided in concomitance with the efficient control of dissolved oxygen level. As a result, the cell concentration reached 130 g/L and rGuamerin expression level was 450 iu/L, which was more than 40% increased result comparing with the fed-batch process using manual control of methanol feeding rate.
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The production of xylanase from Aspergillus niger mutant in SSF was optimized by' using statistical experimental designs. An inoculum size of
$5{\times}10^5$ spores/g. initial moisture content of 65 %. cultivation time of 5 days and 10 times concentration of basal medium containing 50 times concentration of CSL were optimum for xylanase production ‘ Under the optimized conditions. the activity and productivity of xytanase obtained after 5 days of fermentation were 5.071 IU/gram of rice straw and 14.790 IU/l.h. respectively. -
High cell density cultivation of Pseudomonas putida is often necessary for the VOC removal bioreactor. Supplying the feeding solution of C and N sources could accelerate the growth of cells. We changed the component of feeding solution and feeding time. showing that P. putida could be grown to a high density.
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The effect of agitation speed and aeration rate on mTG production and cell growth by Streptoverticillum morbarense was investigated. Dissolved oxygen was controlled by on-line computer-controlled fermentation system. The agitation speed and aeration rate of 2.5 L fermentor ranged from 330 to 360 게m and 1 vvm to 4 vvm, respectively. The highest mTG production was 2.1 U/mL when dissolved oxygen level was 20%, and it was improved almost 1.1 times in comparison with that without dissolved uxygen control.
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The dextran prodution by Leuconostoc mensenteroids NRRL-B512F was studied in a synthetic medium from sucrose as a sole carbon source. Especially, effect of nitrogen source was treated and compared in this study. In oder to maximize the cell growth and dextran produtivity through fermentation two nitrogen sources, yeast extract and tryptone, were used with various concentrations. At the end of fermentation, when the concentration of yeast extract was 9g/L we can obtain the maximum dry cell weight(14.1g/L), dextran dry weight(25.4g/L) and productivity(1.4g/L
${\cdot}$ hr). -
In this experiment, we tested various nitrogen sources and then culture condition was optimized for industrial applications. The batch culture of Candida magnoliae SR101 grown in a defined medium supplemented with light steep water (LSW) as a sole nitrogen source showed a relatively high yield of erythritol production (53%), which was slightly higher than that using yeast extract as a nitrogen source, while the productivity and cell mass were maintained at similar levels. For the optimization of culture condition, the batch culture was performed. When the concentration of LSW was 65 mL/L in the defined medium containing 250 g/L of glucose, the concentration, yield and productivity of erythritol were 110 g/L, 44%, and 0.66 g/L-hr, respectively. The high yield and comparable productivity obtained with a cheap nitrogen source could be expected as a basis for the mass production of erythritol in the industrial scale.
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팽나무버섯균의 배양환경조사에서 최적배양온도는
$20^{\circ}C$ , pH는$6.0{\sim}7.5$ 탄소원은 yellow sugar. potato starch. 질소원은 soybean flour. Yeast extract. 무기염류는$KH_2PO_4,\;MgSO_4,\;7H_2O$ 를 0.05%(w/v)에서 우수한 생장을 나타냈다. 액체종균 배양 실험에서는 전 배양시 erlenmeyer flask에서 6 일간$21^{\circ}C$ , 125rpm으로 배양 후 본 배양시 5% 접종량, 1.0vvm 통기로 4-5 일 배양하였을 때 균체량이 높게 나타났다. -
Traditionally, Cordyceps species have been used as a part of herbal medicine in Oriental countries, including Korea a for intemal health, vigorosity and to cure different diseases related to heart, lung etc. In the recent years, research on artificial fruiting of different Cordyceps species including C. militaris has been carried out in the world because of their medicinal value. Variationas well as instability occur during artificial fruiting. Instability observed in the in vitro fruiting of C. militaris is reported in the present study.
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본 연구는 Lentinus edodes의 액체배양을 통하여 물리
${\cdot}$ 화학적인 방법을 이용, 고농도의 탄수화물 복합효소를 얻어 hemicellulose와의 반응을 거쳐 고수율의 아라비 녹실란을 얻는데 그 목적이 있다. 온도$24^{\circ}C$ , pH 5.5. working volume 100mL, 접종비 5%. 200rpm이며 가장 적합한 C-source 로서는 glucose가 선택되었으며 N - source로서는 yeast extract가 선택되었다. -
Recombinant lipase gene (pYEGA
${\alpha}$ -lip) originated from Bacillus stearothermophillus Ll was overexpressed in Saccharomyces cerevisiae. The lipase gene expression level was compared by controlling a constant specifjc growth rates(${\mu}$ = 0.03, 0.05, 0.07 and$0.1h^{-1}$ . Cell g개wth was successfully controlled at the desired rates by feeding rate of glucose and the formation of by-product or accumulation of the glucose was not observed. Above the growth rate of$0.1h^{-1}$ . the desired growth rate could not be achieved caused accumulation of by-products(ethanol). The lipase production increased as the specific growth rate decreased. The specific production rate at the lowest specific growth rater(${\mu}$ =0.03) was above 2- folds than the others. -
Ultroviolet과 NTG 처리를 통한 mutagenesis를 통해 TAPS 생산균주인 Pichia ciferrii ATCC 14091로부터 많은 mutant들을 얻었으나 Sudan Black B 염색법과 콜로니 형태 관찰을 통하며 TAPS 생산이 우수한 변이균주를 선별하였다. 또한 sodium acetate 첨가를 통하여 TAPS 생산을 향상시켰다. 이는 TAPS가 포화중성 지방산인 palmitate와 serine의 축합반응으로 생성되며, sodium acetate로 부터 생성된 acetyl-CoA에 의해 아세틸화되어 세포 밖으로 분비되기 때문이다.
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답토에서 분리한 균주는 Candida sp. HY200이라 임시 명명하였고, Candida tropocalis 보다 짧은 시간에 xylose를 소모하고, 당내성이 우수하며, flocculation의 특성을 갖고 있다. 260 g/L의 고농도 xylose 배지에서 xylitol 발효는 수율 79%, 생산성 2.14 g/L
${\cdot}$ h의 결과를 얻었다. -
Motierella alpina DSA-12 의 회 분식 발효에서
$MnSO_4$ 첨가로 작은 pellet을 형성하게 하여 유가식 배양으로의 적용 가능성을 보았으나,$KH_2PO_4_4$ 의 경우에는 균체증식에는 효과가 있었지만, 균체가 풀어져 자라 점도가 증가하여 ARA 의 합성이 억제되었다. 유가식 배양에 14 % 암모니아 용액을 사용할 때 균체증식과 총지질의 함량에 영향이 있음을 확인했으며, 62.1 g/L의 균체량에 60% 이상의 지질 함량으로 12.0 g/L 의 아라키돈산을 생산할 수 있었다. -
The effect of agitation speed on the production of mycelial growth and exo-biopolymer in bioreaetor culture was investigated. The maximum production of mycelia and exo-biopolymer was obtained at 350 rpm, where the maximum concentrations of mycelial growth and exo-biopolymer were 62 g/L and 23 g/L, respectively. The effect of agitation speed on the hyphal length and the number of tips was examined. The hyphal length and the number of tips of Cordyceps sinensis 16 in bioreaetor culture at 350 rpm were increased up to 660
${\mu}m$ and 14/ml, respectively. -
본 연구는 P. japonira의 액체배양을 통해 HPLC를 이용하여 유용물질인 cordycepin의 농도를 분석하였다. 배지성분중 무기질소원, 아미노산, 무기염류 및 금속이온의 영향을 검토하였다. 그 결과 균사체의 경우에서는 cordycepin의 농도가 매우 낮음을 알 수 있었고, 배양여액의 경우에서는
$(NH_4)_2HPO_4$ . histidine.$CaCO_3$ 등을 첨가했을 때 control에 비해 높은 농도의 cordycepin의 생성을 확인할 수 있었다. -
The optimal temperature, pH and aeration rate for spore production by Bacillus polyfermenticus SCD in 500 ml shake flask and 5-1 jar fermenter were found to be
$32^{\circ}C$ , 7.0 and 1.0 vvm. respectively. When batch culture processes was performed under optimized culture conditions. viable cells were$3.3{\times}10^{10}$ CFU/ml and spore cells were$3.3{\times}10^{10}$ CFU/ml. Fed-batch culture processes were also examined with regard to higer maximum viable cell and spore production. The highe viable cells and spores were obtained in 5-1 jar fermenter at 72 h cultivation time by strategy in an intermediate feeding mode with 60% glucose solution 150 ml and 5% soybean flour solution 150 ml fed to the fermenter twice, and the productivity of spore cells was significantly increased. Finally. volumetric productivity of spore cells on fed-batch culture indicated$9.9{\times}10^8$ CFU/ml/h, which was approximately 2 times higher than batch culture. Thus, fed-batch culture show a promise as an industrial production method. -
In order to maximize the cell growth and the biosurfactant production by the Pseudomonas aeruginosa BYK-2(KCTC 18012P), in the fed-batch fermentation processes were performed varying the feeding medium concentrations and the feeding rate. Feel-batch culture was performed with the optimal agitation speed of 200rpm and the aeration rate of 0.67vvm in a 7L Jar fermentor containing 3L of modified medium and 2.0-2.5%(v/v) fish oil as a carbon source. Addition of fish oil(2.5mL/l00mL modified medium), when fish oil was depleted, the cell and biosurfactant concentration were 6.1g/L and 22.7g/L, respectively.
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인산가용화균 Penicillium sp. PS-113 의 포자를 액상비료로 제제화 할 때 분산력 개선 및 균의 장기보존을 위해 다양한 농도의 Trio와 Trio에 각종 첨가제를 첨가하여
$4^{\circ}C$ 와$25^{\circ}C$ 에서 보관한 후 2주, 4주, 2개월, 4 개월 간격으로 시료를 채취하여 PDA 평판배지에서의 균수를 측정하였다. 그 결과에 의하면 0.1% Trio(v/v)에서 포자의 분산력과 생존률이 가장 좋았다. -
본 연구는 주변에서 흔히 구할 수 있는 여뀌를 이용하며 유용한 미생물을 대량생산 할 수 있는 값싼 배지를 개발하는데 있다. 길항미생물 B. lentimorbus G-74를 이 배지를 이용하여 최적화한 결과, 30% 여뀌즙액 배지.
$35^{\circ}C$ . pH 5.0의 조건에서 가장 높은 균체성장을 보였다. -
The production of fumaric acid in shaken flask cultures by Rhizopus oryzae KCTC 6946 was studied. The effects of various carbon and nitrogen sources on fumaric acid production were investigated. The strain fermented starch (or glucose) and corn steep liquor (or polypepton) better than other carbon and nitrogen sources to fumaric acid. When C/N ratio of carbon and nitrogen source was 41.7, the concentration of fumaric acid produced with 2N NaGH as a neutralizing agent was more than 10 g/L after 3 days.
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The production of fumaric acid in a novel fixed-layer fermenter using Rhizopus oryzae KCTC 6946 was studied. When yeast extract and corn steep liquor were used as nitrogen sources, fumaric acid produced was 6.4 g/L and 6.8 g/L, respectively. Compared with the flask cultivation, fumaric acid concentration was about 200% when yeast extract was used as a nitrogen source, but reached to 93% when corn steep liquor was used.
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In this study a repeated batch production of lactic acid was investigated for the purpose of reducing amount of yeast extract dosage. First batch operation was performed with nutrient rich media(glucose 100-150 g/
${\ell}$ , and high yeast extract contents; 15 g/${\ell}$ ), and subsequential batch operations were performed with nutrient poor media(glucose 100-150 g/${\ell}$ , and reduced yeast extract contents; 4-5 g/${\ell}$ ). Volumetric productivities(6.03-6.20 g/${\ell}{\cdot}h$ ) and substrate conversion rate(94-98%) of eve η subsequential batch operation were maintained with the same level of first batch operation(6.19 g/${\ell}{\cdot}h$ , and 99%, respectively), when concentrations of glucose and yeast extract were 100, and 4 g/${\ell}$ respectively. -
불용성 인산염인 hydroxyapatite를 분해하여 인산을 생성하는 미생물인 P. agglomerans의 성장에 따른 인산의 생성량을 여러 산으로 처리하였을 때와 비교하여 보았다. P. agglomerans 의 성장에 있어서 필요한 인산의 양은 300mg/L에서 361mg/L 정도의 인산을 소모하였다. 또한 여러 유기 및 무기산으로 4% 의 hydroxyapatite를 처리하였을 때에 0.01N 의 시트르산과 옥살산으로 처리하였을 때 만이 인산의 생성량은 P. agglomerans 에서 보다 높은 각각 702와 537mg/L 이었고 배양후 48 시간이 지났을 때 P. agglomerans 의 유리인산의 최대가용화량은 465mg/L이었다.
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The gellan was produced by Pseudomonas elodea ATCC 31461 under aerobic condition. Gellan provides various functionalities such as gelling, suspending, stabilizing, emulsifying and binding properties in aqueous systems. In this study, the effect of glucose concentration and nitrogen sources concentration, bacto peptone and
$NH_4NO_3$ , on the cell growth and the production of gellan were evaluated. The maximum specific yield (g gellan/g cell) of 2.22 was obtained at 1.0% of glucose. Bacto peptone increased cell growth. And nitrogen limitation was essential for higher production of gellan. The highest cell and gellan production were abtained at 0.5 g/${\ell}$ of bacto peptone without$NH_4NO_3$ . -
For isolating and identifying Bifidobacterium spp. originating from Korea, feces were sampled from healthy Korean infants nursery school and postpartum care center. Through the use of gram staining and microscopic examination for cell morphology, 87 bacterial strains presumed to be the Bifidobacterium strains were isolated from 59 Koreans. To identify the Bifidobacterium strains at the genus level, these bacteria were then analyzed using the TLC method. As a result, 29 of the isolated strains were confirmed as members of the genus Bifidobacterium. 29 Bifidobacterium strains were tested acid, bile salts and oxygen tolerance and investigated antioxidative effect specially. And determined the superiority of 5 strains out of 29 Bifidobacterium strains. Finally, the selected bifidobacterium was identified with using designed 16S-ITS rDNA primer.
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The continuous production of L -proline was studied using L-histidine auxotrophic mutant of Corynebacterium acetoacidophilum under various substrate limited conditions. Among the
$NH_4\;^+$ $PO_4\;^3$ and L -histidine limited conditions, the highest production of L -proline was observed under the L-histidine limited condition. Under$NH_4\;^+$ and$PO_4\;^3$ limited conditions, no or poor L-proline production was observed, respectively. For the kinetic parameters under L -histidine limitation the specific rate of L -proline production was increased with dilution rate upto$0.1hr^{-1}$ but decreased above$0.1hr^{-1}$ . The volumetric rate of L -proline production was showed similar pattern with specific rate. The dried cell weight was gradually increased according to decrease the dilution rate. Specific rate of glucose consumption was proportionally increased with dilution rate. The results of continuous culture (higher production of L-proline at dilution rate$0.1hr^{-1}$ ) will be used in fed-batch culture for the control of cell growth rate and mass production of L-proline. -
본 실험은 erinacine 을 생산하는 Hericium erinaceus 균사체의 최대생산을 목적으로 기본배지를 토대로 수행되었다. 따라서 선정된 몇가지 대표적 carbon source와 nitrogen source를 비교
${\cdot}$ 검토하였다. 그 결과 carbon source에서는 glucose에서 다른 source 에 비하여 높은 균사체 생산량을 보여주었으며 nitrogen source에서는 yeast extract에서 높은 균사체 생산량을 보여주었다. 또한 C/N ratio 검토를 근거로 본 실험에서는 glucose 20g/L 와 yeast extract 10g/L를 modified medium으로 선정하였다. 그 결과 균체량은 11.78g/L, Polysaccharide는 l.03g/L 로 측정되었다. -
배양 조건으로 온도는 4, 11, 18, 24,
$32^{\circ}C$ 로 배양하여,$24^{\circ}C$ 에서 Lipid 내에 약 42.3%의 DHA 최대 수율을 보였으며, 교반속도는 50, 100, 150, 200rpm 으로 실험하여 l00rpm에서 최대수율로 42.1% 올 얻었다. 초기 당농도는 5, 8, 11, 14, 17, 23, 29, 35g/L로 주어 8g/L에서 Lipid 내 DHA 농도가 43.1%로 나타났으며, N/C 비율은 glucose 5 g/L로 고정하여0.1, 0.2, 0.4, 0.6, 0.8 에서 38-40 % 로 거의 일정하게 나타났다. -
Ferritin an iron-storage protein. is found in bacteria and some animal tissues such as liver, spleen and bone marrow. It is more effective and causes less side reactions than traditional ferrous sulfate, which has been used primarily to treat iron deficiency in pregnancy anemia. Currently, the ferritin extracted from bovine and equine spleens are sold as a commercial product. Its markets are several hundreds of million US dollars. However, because of recent warnings against the viral diseases of animal origins such as mad cow disease, a safer ferritin is sought after. In this study, a production process for human ferritin was successfully developed. The amount of its produced in yeast is high enough to be economically viable.
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CMP(caseinomacropeptide) is known to be a peptide which controls the gain of body weight and eventually will be used as a new candidate to control obesity problem. In this study, CMP gene was obtained using RT-PCR and ligated to secretion vectors having different kinds of promoters and P.pastoris and S.cerevisiae were transformed with these vectors. Colonies showing high titre of CMP cxpressecl were chosen and fed-batch fermentation is being carried out with these transformant to test economic feasibility
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Human garnulocyte-colony stimulating factor(hG-CSF), a hematopoietic growth factor
$^{1)}$ , was produced and secreted from tobacco cell suspension. hG-CSF produced from tobacco cell suspension culture is biologically active form. The produced amount of hG-CSF is about 100${\mu}g/L$ in 9 days after inoculation. -
In this study. an efficacy study of Portulaca Extract (PE) and
${\beta}$ -glucan. candidates for cosmetic additives. was pedormed using artificial skin model (AS). The AS consists of collagen gel matrix populated by ATCC human skin fibroblast cell line that is overlaid with epidermal human skin keratinocyte cell line. Cytotoxicity and anti - inflammatory activity of PE and${\beta}$ -glucan were assessed using monolayer and AS models by measuring cell viability and the secretion of interleukin -1${\alpha}$ . -
배양된 대황으로 모상근으로부터 추출한 물질에 대한 분획별 신장상피세포에 있어서의 세포 독성을 조사하였다. l 수층과 클로로포름 층으로부터 얻은 대황 모상근 추출물모두 농도의 증가에 따라 세포에 미치는 독성이 증가하였다. 2. 클로로포름층으로부터 얻은 대황 모상근 추출물이 수층으로부터 얻은 대황 추출물보다 세포에 미치는 독성이 크게 나타났다. 콜로로포름층 분획의
$MTT_{50}$ ,$NR_{50}$ ,$SRB_{50}$ 은 각각 289.3${\mu}g/ml$ . 302.7${\mu}g/ml$ . 433.8${\mu}g/ml$ 이었고, 수층 분획물의$MTT_{50}$ ,$NR_{50}$ ,$SRB_{50}$ 은 각각 475.8${\mu}g/ml$ . 428.3${\mu}g/ml$ . 549.5${\mu}g/ml$ 이었다. 3. 세포독성 측정방법에 따라 차이를 보였으며 수층 분획의 경우 NR정량법에서 클로로포름 층 분획의 경우 MTT정량법에서 독성 정도가 더 높게 나타났다. -
To determine the effect of ERp57 expression on thrombopoiein (TPO) productivity in recombinant Chinese hamster ovary (rCHO) cells, TPO producing rCHO cell line with doxycycline-regulated ERp57 expression \Vas developed. The Erp57 expression level could be regulated by addition of different concentrations of doxycycline to culture medium. The doxycycline concentration of I
${\mu}g/mL$ was high enough to suppress the ERp57 expression. Up to 5${\mu}g/mL$ doxycycline concentration used in culture medium, no observable cytotoxic effect of doxycycline was detected during culture. Overexpression of ERp57 、 vas found to increase the specific TPO productivity ($q_{Tpo}$ ) without growth inhibition, probably due to the chaperone-like activity of ERp57 in CHO cells. -
Angiopoietin-2 (Ang2) is a naturally occurring antagonist for angiopoietin-l (Angl) and its Tie2 receptor during vasculogenesis, Although angiopoietins have been expressed in several mammalian cell lines, their expression levels are low. Recombinant Chinese hamster ovary (CHO) cell lines expressing a high level of human Ang2 or its analog, human
$Ang2_{443}$ , with an amino-terminal FLAG-tag were constructed by transfecting the expression vectors into dhfr-deficient CHO cells and subsequent gene amplification in medium containing stepwise increments in methotrexate level. Secreted Ang2 or human$Ang2_{443}$ were purified from the cultured medium using an anti-FLAG- agarose affinity chromatography, The purified Ang2 and$Ang2_{443}$ migrated on SOS-PAGE as a broad band, characteristic of glycosylated protein. Their biological activity in vitro was demonstrated in a serum deprivation-induced apoptosis assay. Ang2 at high concentration, like AngI, can be an apoptosis survival factor for endothelial cells through the activation of the Tie2 receptor. -
Chitosan-alginate capsules were formed by the electrostatic interactions and had appropriate mechanical strength, permeability to albumin and stability to hepatocyte. Pig hepatocytes were isolated and immobilized in chitosan-alginate capsules. Encapsulation in 3 minutes and spheroid formation period of 24 hours were optimum condition for the high liver function. Pig hepatocytes density of
$90.{\times}10^6$ cells/mL in capsules was suitable for the application to bioartificial liver support system. -
강한 제초활성을 띠는 곰팡이 균주 YK101의 배양조건을 최적화하기 위하여 균사와 균체 생산에 대한 온도, 교반속도 그리고 배양배지의 영향을 조사하였다. YK101의 최적 배양온도와 교반속도는 각각
$28^{\circ}C$ , 150rpm 이었다. 최적화된 배지조성은 1.0$^{\sim}$ 2.0% total sugar, 1.0% yeast extract 그리고 0.05%$MgSO_4$ ${\cdot}$ $7H_2O$ 이었다. -
체외에서 hematopoietic cells의 배양은 필수이식으로 하여금 hematopoietic malignancies로 인해 고통받는 환자들을 치료할 수 있다. 본 실험에서는 골수의 초기 농도
$1.5{\times}10^6cells/ml$ 로 하여 IL-3(5ng/ml), SCF(5ng/ml)과 FL(25ng/ml)의 성장 인자들을 첨가함으로써 bone marrow의 전체 cell의 증식은 생성시키지 못 했지만 LTC-IC는 3.6배의 증식을 가져왔다. -
참당귀 현탁세포배양시 생산되는 ECP는 세포벽을 가수분해하는 효소를 첨가할 경우 그 생산이 증진됨을 확인하였다. Pectinase의 경우 최대 0.97 g/L로 1.39 배, Pectinex의 경우 최대 1.04 g/L로 1.35 배 증진시켰다. Pectinase는 세포벽의 fragment를 방출시켜 세포의 생장과 ECP 생산을 증가시키는 것으로 판단된다. Pectinex는 저농도 (1 FDU U/L)로 처리하였을 경우 세포의 생장과 ECP 생산을 증가시켰다. 고농도로 갈수록 생장에 저해될 만큼의 fragment를 방출시켜 세포의 크기가 작아지면서 생산되는 ECP의 양은 증가되는 것으로 여겨진다. 따라서 세포벽을 가수분해하는 효소는 ECP 생산에 긍정적인 영향을 미친다는 것을 알 수 있었다.
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Growth and tropane alkaloids(hyoscyamine and scopolamine) contents were studied in root cultures from Scopolia paruiflora. All excised roots grew well, even without an addition of a growth regulators. Scopolia roots could be divided scopolamine-rich species. Among the culture media, SH medium was the best for tropane alkaloids production from the hairy roots, whereas the growth increased in SH medium. In precusor experiments, feeding of hyoscyamine was promotive for scopolamine formation. Abiotic elicitors made a slightly production promotion effect.
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The effects of biotic elicitors, organic acids, and environmental changes on the growth of Panex. ginseng hairy roots were investigated in the shaking flask culture. Among the organic acid tested, gluconic acid was found to be the most efficient in the hairy roots growth. And citric and succinic acid were facilitated the growth of hairy roots.
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There were many reports on the natural antioxidants, but only tocopherol has been widely used despite of its high market price because of its recognized safety. On the other hands, antimicrobial effects of various plant extracts also have been extensively studied. There exist many substances showing antimicrobial activity in plants and their activities have been studied.
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This study was conducted to investigate the antimicrobial activity of the Omija extracts against the microorganism. The extracts were shown the antimicrobial activity, 10 percents e χ tracts inhibited the growth of bacteria in the various temperature ranges. However no affect shown the other fungi except the bacteria. As the results antimicrobial activity of the all extracts were not destroyed in the high temperature furthermore it shows the strong antimicrobial activity against the autoclave at
$121^{\circ}C$ for 15min. -
Adsorption characteristics on the biomass of Chlorella sp. HA -1 were investigated in binary system with
$Pb^2$ ,$Cu^2$ ,$Cd^2$ , and$Zn^2$ ions. For the adsorption tests of single metal, Langmuir model was showed good correlation for equilibrium data compared to Freundlich model. Maximum metal uptakes increased as follows:$Pb^2$ >$Cd^2$ >$Zn^2$ >$Cu^2$ , whereas the affinity showed different trends:$Cu^2$ >>$Cd^2$ >$Zn^2$ >$Pb^2$ . In binary metal system,$Cu^2$ ions inhibited sharply the adsorption of other metal ions except$Pb^2$ ions because of the high biosorption affinity of$Cu^2$ ions. In the case of$Cu^2$ and$Pb^2$ system, there was no significant inhibition on metal uptakes. The results of metal adsorption in the binary system could be explained well on the basis of Langmuir parameters evaluated. -
Characteristics of
$CO_2$ fixation by Chlorella sp. HA -1 were studied in a high cell culture using semi-continuous mode. As a result, it may be possible to obtain not only high cell concentration but also effective$CO_2$ removal at a moderate dilution ratio, which is' the most significant factor to control the microalgal growth in the semi-continuous mode. -
Characteristics of
$CO_2$ fixation by Chlorella sp. HA -1 against NO and$SO_2$ were investigated. Culture pH in nitric oxide gas remained stable indicating that nitric oxide was not likely to be a problem for growth, while$SO_2$ could inhibit the cell growth because of pH drop. Chiarella sp. HA -1 containing 10%$CO_2$ from stack gas can be tolerant to 100 ppm nitric oxide and 100 ppm sulfuric oxide through pH control. -
An microorganism able to degrade ethylene glycol(EG) was developed. Using this microorganism, biological treatment of ethylene glycol was studied in Erlenmeyer flasks and a laboratory scale stirred loop bioreactor. The removal efficiencies of ethylene glycol from synthetic wastewater were 91.6%
${\sim}$ 97.7% at$30^{\circ}C$ ${\sim}$ $40^{\circ}C$ , and 96.3%${\sim}$ 97.9% at initial pH 9${\sim}$ 11 respectively. Also the removal efficiencies of ethylene glycol were found to be more then 92% at initial ethylene glycol concentration of 300mg/L${\sim}$ I400mg/L. In treatment of weight loss treatment wastewater using Erlenmeyer flasks, the removal efficiencies of ethylene glycol were 79.6%. 82.5%. 77.6%. and 71.3% at initial pH 9. 10. 11. and 12.4 after 11 days of reaction. Moreover in treatment of complex dyeing process wastewater. the residual ethylene glycol was not detected at the initial pH 10.0 and pH 11.3 after 4 days of reaction. When stirred loop bioreactor was used for removing ethylene glycol, the residual ethylene glycol was not detected after 108 hrs and 60 hrs of reaction in batch treatment of weight loss treatment wastewater and complex dyeing process wastewater. -
Recently, our country's piggery has been becoming large-sized and crowded gradually in scale. Thus, the environment in a piggery is getting worse, which leads to a drop in livestock's immunoactivity. Therefore, livestocks are exposured to many diseases(stress, hypertension, stomach ulcer etc.). In this paper, our intention is to design a low cost ozone-generating device with high capacity to maintain a reasonable ozone level, that is necessary for cleaning the environment in a piggery, but is not too high to cause any harmful influence to human beings and livestock. The results showed that the UV-lamp tube with baffle has an increase of 25% in ozone generation efficiency compared to without baffle and the short retention time of air or high inlet air rate shows high level of ozone.
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본 연구에서는 각종 유기성 폐수, 생활하수, 분뇨 등의 악취제거를 생물학적 방법으로 처리하기 위한 효율적 고형 미생물 탈취제의 개발을 위해 악취분해 및 유기물 분해 활성이 우수한 유용 미생물들을 선발하고, 안정적이며 경제성 있는 제조방법을 개발하고자 하였다. 먼저 다양한 환경으로부터 농화배양을 통해 유용 광합성 미생물 및 각종 악취환경의 물리 화학적 성상에 부합하는 활성 미생물들을 탐색, 확 보하였다. 또한 미생물의 고농도 배양, 세포의 회수공정, 미량 영양원 및 미생물 안정화제의 첨가, 특히 체제의 재활성화 측면에서 미생물들의 장기 안정성을 도모하기 위한 미생물 전달매체 및 제형화제의 선별과 제형화 기법의 기초를 확립하였다.
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Fossil fuels such as coal and crude oil contain various organic sulfur compounds. Combustion of these fuels emit sulfur oxides which are considered as msjor air pollutants causing acid rain problem. Among various organic sulfur compounds, aromatic sulfur compounds of thiophenes which constitute major sulfur fractions of heavy oils are not easily removed by hydrodesulfurization. Many peroxidase and hemoproteins are known to oxidize dibenzothiophene (DBT) to dibenzothiophene-sulfoxide(DBT - sulfoxide) then dibenzothiophene- sulfone (DBT-sulfone). The oxidation of DBT by the immobilized hemoproteins in n-octane was increased significantly when the hemoproteins were deposited on celites of the particle size between 0.75 - 1.0 mm and a conventional substrates. such as t-butyl hydroperoxide and cumene hydroperoxide. In anhydrous organic solvents with log P values larger than 4.0 DBT was completely oxidized by cumene hydroperoxide catalyzed by cytochrome c deposited on celites.
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수영 하수처리장의 소화조에서 농축조로 보내지는 혐기성 슬러지를 탈기된 증류수와 1:1 로 희석한 후 연속식 반응기에 주입한 후 합성폐수의 농도를 변화시켜 공급한 결과, 담체 표면적당 생물막 부착량은 23 일 이후에 그 양이 일정해지는 경향을 나타냄을 알 수 있었다. SEM 사진에 의해서는 미생물 형태를 명확히 파악할 수 없고 특히 메탄 형성 미생물의 존재를 규명하기 어려워 형광현미경을 이용하였다. 형광현미경에 의한 담체에 부착된 미생물의 관찰 결과 메탄생성균을 확인할 수 있었고, 시간이 증가됨에 따라 일정하게 증가됨을 볼 수 있었고, 23 일 이후엔 농도 변화엔 큰 영향이 없이 일정함을 알 수 있었다.
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본 연구는 메탄을 최대로 발생시킬 수 있는 최적조건을 탐색하는데 있다. 메탄을 많이 발생 시킬 수 있는 최적 온도와 pH를 결정한 다음, 여러 가지 탄소원에 대해 조사하였다. 온또는
$25^{\circ}C$ .$30^{\circ}C$ .$55^{\circ}C$ 에서, pH 는 pH 2, 4, 6, 8. 10 에서 , 그리고 탄소원은 methanol. formic acid. sodium acetate. succinic acid, glucose 에서 조사하였다. 결과적으로 볼 띠 1. 온도는$55^{\circ}C$ . pH 는 중성부근. 탄소원은 methanol 인 조건에서 가장 많은 메탄을 얻을 수 있었다. -
Korean food waste, one of the abundantly available but environmentally problematic organic wastes in Korea, was utilized as solid-substrate by fungal strain Aspergillus niger ATcC 6275 for the production of enzymemixture containing amylase, cellulase and xylanase. The enzyme mixture can be used as high value-added animal feed. Solid-state fermentation method yielded a 84-fold enhancement in xylanase activity compared with submerged fermentation method. The effect of incubation period, incubation temperature, pH of medium, moisture content, inoculum size and enrichment of the medium with nitrogen and carbon sources were observed for optimal production of these enzymes The optimal amylase activity of 33.10 U/g, cellulase activity of 24.41 U/g, xylanase activity of 328.84 U/g were obtained at 8 days incubation with 50%(w/w) soy bean flake, with incubation temperature of
$25^{\circ}C$ , pH of 6.38, optimal moisture content of 55% and with inoculum size of$3.8{\times}10^6$ spore/g. Enzyme activities were enhanced when ImM$CaSO_4$ , 2% Malt extract and 2% galactose were added as mineral, nitrogen and carbon enrichment respectively. -
본 연구는 제약폐수 처리에 있어서 폐수처리장내의 미생물 활성을 최대로 하여 운전효율을 높이는 것을 목적으로 하고 있다. 각 부하에 따른 영향을 살펴보고 각종 동력학 계수를 측정하여 실제 폐수처리 공정에 있어서 최적의 조건으로 운전할 수 있도록 하는 것이 목적인데, 이에 MLSS 부하, COD 부하에 따른 결과들을 구할 수 있었다. 반복실험을 통하여 더욱 정확한 동력학 계수를 측정할 수 있으리라 기대한다.
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A parallel TBF system that is consisted of two TBFs was developed f ‘ or the long-term treatment of gas-phase trichloroethylene (TCE). Each TBF was operated for TCE degradation or reactivation in a parallel mode, and the effect of switching time and operation variables between the two reactors was investigated. Within 12 hr after switching from TCE degradation to reactivation mode, the MO activity increased up to the initial level. More than 50 % of TCE was degraded for feed concentrations ranging from 5 to 17 ppmv, and completely 100 % removed at concentration of less than 5 ppmv, while TCE removal decreased severely over 28 ppmv. In various empty bed retention times (EBRTs), ranging 상 om 5.2 to 10.7 min, the optimal EBRT was 10.7 min that TCE conversion achieved more than 50 %. For the inlet loading below 23.4 mg TCE/L/day, TCE was entirely removed. The maximal TCE elimination capacity in this system was about 66.63 mg TCE/L/day. During the continuous treatment of TCE over 3 months, TCE removal efficiency was maintained at the range of about 50 %. In these results, the parallel TBF system can be available for the continuously TCE biodegrading operation.
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One of the most promising TCE treatment systems is trickling biofilter (TBF), in which monooxygenase, the corresponding enzyme for initiating growth substrate oxidation, fortuitously transforms TCE via cometabolism. TCE. however. is not easily treated by simple cometabolic biotransformation. This is mainly due to the toxicity of TCE to microbial cell and monooxygenase. In this study, we cleveloped and operated a two-stage CSTR/TBF system for the long-term continuous treatment of TCE. In the two-stage biotransfon11ation system, CSTR with cell recycle from TBR was coupled to the TBR for the reactivation of the cells deactivated during TCE degradation.
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Microbiologically influenced corrosion (MIC) of metal is common in the natural environment and sulfate reducing bacteria are representative microorganisms for MIC. We found that biofilm fomlation by SRB on the metal surface might be controlled by quorum sensing, which is a cell density dependent regulation of cell metabolism. As cell free culture fluids (spent media) of Desulfovibrio vulgaris and D. desulfuricans were tested for quontrn sensing related test strains, it was found that spent media of two SRB induced increased luminescence of Vibrio harveyi BB886 (sensor 1+, sensor 2-) and BB170 (sensor 1-, sensor 2+). Quorum activities of D. vulgaris and D. desulfuricans appeared to be parallel to growth patterns, i.e., it was low in the lag phase, highly increased in the exponential phase, and reached maximum in the stationary phase. Interestingly, however, luminescence of V. harveyi BB886 and BB170 induced by a unit cell mass of the SHB showed a maximal peak in the late lag phase. Hence, it was suspected that quorum sensing of these two SHB play unknown roles in shifting cells from dormant to growth stages.
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Investigation of gene encoding catechol 1,2-dioxygenase from Phenol-degrading, Rhodococcus sp. EL-GT본 연구는 방향족 화합물질 중 페놀폐수에 대한 생물학적 처리를 위해 본 실험실에서 분리한 페놀분해능이 우수한 Rhodococcus sp. EL-GT를 이용하여 catechol 분해 catechol 1,2-dioxygenase 분해활성을 측정하였고, 이것이 ortho-pathway임을 확인할 수 있었다. 또한 다른 연구에서 보고되 Phodococcus rhodochrous NCIMB임을 확인할 수 있었다. 또한 다른 연구에서 보고된 Rhodococcus rhodochrous NCIMB 13259 균주의 catechol 1,2 dioxygenase를 기초로한 primer를 이용하여 PCR을 수행하였으며 이 분해 유전자의 cloning실험을 수행 중이다. 이들 실험을 통하여 Rhodococcus sp. EL-GT의 페놀분해 균의 유전적 구조 및 특징을 검토하고 이를 이용하여 방향족 화합물의 분해능이 보다 우수한 균주의 개발을 시도하고자 한다.
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본 연구는 MEK, MIBK와 BTX 혼합물을 미생물 컨소시엄을 통하여 biofilter를 이용한 이 들 화합물에 대한 제거율을 파악해 봄으로써, 추후에 pilot plant scale을 설계하는 기본 변수로 활용하고자 한다. 미생물의 적응기간인 초기 2일까지의 제거효율은 변화의 폭이 다소 적었으나 3일 이후부터 급상승하여 4일 이후부터 높은 제거효율을 나타내었다. 또한, 혼합 VOCs의 유입 농도에 변화를 주어 이에 대한 biofilter의 운진시간에 따른 제거율의 변화에 있어서도 VOCs 유입에 대하여 초기에는 낮은 처리효율을 보여주었으나 1일이 경과한 후 높은 제거효율을 보였다. 본 연구에서는 처리할 VOCs 물질의 유입 농도 변화에 상관없이 높은 처리효율을 나타냈다 이는 biofilter 에 처음으로 적용한 섬유상 담체의 표면에 운전기간동안 미생물들이 지속적으로 부착되어 유입되는 VOCs 물질에 대한 적응기간을 단축시킬 수 있었던 것으로 사료된다.
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생물 계면활성제의 개발을 위해 MNNG(N-Methyl-N-Nitro- NitrMoguanidjne), EMS, UV radiator 등 random mutation을 유도하여 가장 고기능 유화제 생산 균주를 선별하여 다양한 탄소원에 따른 생육도와 유화활성, 유화 활성에 미치는 pH 등 생물 계면활성제의 생산에 관한 조사를 한 결과 Bunker A에서는 유화활성이 원래 균주보다 최고 약 6배까지 증가했으며 표면장력 또한 40.3dyne/cm 에서 34.0dyne/cm 으로 크게 감소되었다.
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생물학적 폐수처리 (biological treatment)의 슬러지의 활성도 측정을 위하여 슬러지의 대사 열을 측정하는 장치와 소프트웨어를 개발하였다. 슬러지의 활성을 측정하는 호흡계와 같이 간헐식으로 폭기와 침전을 반복하연서 슬러지의 대사열의 monitoring 을 통하여 슬러지의 활 성진단올 할 수 있었다.
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MEK를 단일 탄소원 및 에너지원으로 하는 균주를 춘천시 공단지역 토양으로부터 분리하였고 그 중 Geotrichum sp. MF01 균주는 MEK 분해 시 Michaelis - Menten kinetics를 따랐으며
$K_m$ 과$r_{max}$ 는 각각 5.88 mM. 0.14$h^{-1}$ 로 가장 좋은 분해능을 보 여 주었다. 또 MEK 분해 시 물리적인 흡착이 관여했으나, 대부분은 미생물 대사에 의한 제거였다 . 순수 분리된 미생물을 이용한 biofilter 실험에서는 57일 동안 최대 10$gm^3h^{-1}$ 의 제거율을 얻었다. -
본 연구에서는 중형 크기의 자외선 광축매 반응기를 이용한 최적 살균 조건을 알아보았다. 반응기의 직경에 따른 살균효과는 반응기의 직경이 클수록 살균효과는 감소하였으며,
$TiO_2$ 농도에 따른 살균효과에서는$TiO_2$ 의 농도가 증가할수록 살균효과는 증가하였고 과다한$TiO_2$ 농도에 의한 살균효과의 감소는 본 연구에 사용된 0.6%의$TiO_2$ 농도에서는 관찰되지 않았다. 광촉매의 종류에 따른 살균효과는 glass bead 보다는 백운모를 이용한 bead가 더 우수하였다. 중형 크기 반응기의 살균효율은 1분동안 62%, 5분후에는 94.3%, 15분후에는 99.8%의 살균효율을 보였고 30$mg/{\ell}$ 이상의$H_2O_2$ 를 첨가할 경우 5분후의 살균효과는 99%이상이었다. -
본 실험실에서 개발한 3단계 메탄 발효시스템을 이용하여 음식물 쓰레기를 소화처리하고 그 폐액을 생물 여재막으로 처리하여도 여전히 고농도의 COD, BOD, T-N 그리고 T-P 올 함유하고 있기 때문에 조류를 이용하여 처리하였다. 이 때 T-N, T-P 는 각각 98%, 91% 의 제거율을 보였다. 한편 생리학적인 먹이 연쇄 관계에서 조류를 먹이원하여 생장한 조류를 제거하고자 하였다 . 물벼룩은 조류 배지애서는 10일 후 최대의 개체수를 보였으나 , 생물막 유출수에 조류 (1 x 10
$10^6$ cells/$m{\ell}$ ) 와 물벼룩 5 마리를 접종한 시료에서는 물벼룩은 12 일 후 최대 180 마리로 관찰되었고 그 이후 로 점차 사멸하여 20 일 후 57 마리의 개체수를 나타냈다. 이 때 조류의 개체는 계속적으로 감소하여$1.1{\times}10^5$ cells/$m{\ell}$ 을 보였다. -
본 연구는 종합염색폐수처리장으로 유입되는 염색폐수를 원활히 처리할 수 있는 반응기를 찾아내고자 각 반응기의 성능 및 제거효율, 안전성등을 조사하였다. 선행된 연구에서 종합염색폐수를 1차 생물학적 처리를 위하여 활성슬러지 생물반응기를 통하여 처리한 것보다 활성탄 담체를 이용한 Jet loop reactor(JLRAS)를 개발하여 처리한 것이 더욱 제거효율을 향상시켰다. 본 연구에서는 활성탄 담체를 이용한 Jet loop reactor를 이용함으로써 F/M ratio 가 크게 증가하여 2.3일 때 feed의 증가량에 따른 JLRAS 에서 보다 높은 비기질제거율을 보여주고 있으며
$COD_{Mn} /BOD ratio를 조사하여 유출수에 난분해성 물질이 많이 제거되어지고$COD_{Mn} loading rate, 즉 부하변동에 따라서도 안정한 수질을 얻을 수 있는 것을 알 수 있었다. -
A treatability study was conducted using a hydrocarbon-contaminated soil for the oPtimization of bioremediation strategy best fit to a given set of contamination. The applicability of nutrients, biosurfactant, and oil-degrading microorganisms were examined by monitoring
$CO_2$ evolution and oil degradation The addition of inorganic nutrients in the form of slow released fertilizer accelerated the initial rate of$CO_2$ evolution by a factor of 3. The application of oil-degrading microorganisms did not significantly increased$CO_2$ evolution or biodegradation efficiency. Application of a commercial biosurfactant was most effect in terms of the total$CO_2$ evolution and the oil degradation rate. The results indicate that$CO_2$ evolution measurement was found to be a simple and reliable countermeasure of crude oil hydrocarbon mineralization for the rapid determination of the best-fit bioremediation strategy. -
Yeast 유래의 미생물 생리활성물질(GL)에 대한 살조특성은 다음과 같다. C. polykrikoides 및 3종의 와편모조류에 대한 운동성 저해는
$MT_{50}$ 은 S. trochoidea 는 5${\mu}g/ml$ 에서 5분 이내에, P. minimum 및 H. akashiwo는 30${\mu}g/ml$ 에서, C. polykrikoides는 200${\mu}g/ml$ 에서 5분 전후로 나타났으며, 이로 인해 저농도에서 와편모조류의 저해가 가능했다. 와편모조류의 사멸효과는 최종농도 10${\mu}g/ml$ 이상에서 와편모조류의 대부분의 살조가 나타났으며, 살조유형을 조사한 결과, GL이 와편모조류의 세포벽을 직접적으로 공격함으로써 세포벽의 파괴를 야기함을 알 수가 있었다. -
본 연구에서는 P. agglomerans를 이용하여 불용성 인산염인 hydroxyapatite 와 인광석을 가용화 하여 유리 인산을 생산하였고, P. agglomerans를 Ca-alginate에 고정화하여 이를 불용성 인산염을 가용화시키는 가능성올 조사하였다. HY 배지에 서
$30^{\circ}C$ , lOOrpm 으로 pH 7에서 48시간 배양한 경우 520mg/L 의 유리인산이 생성되었고 hydroxyapatite 대신 같은 농도의 인광석을 첨가하였을때 생성되는 유리 인산 의 양은 86.09mg/L였다. 또한 P. agglomerans를 Ca-alginate에 고정화하였을 때 HY 배지에서 같은 조건으로 120 시간 동안 계속적으로 인산이 생성되었고 , 이때 생성된 인산의 농도는 74Omg/L였으며, 인광석을 첨가한 경우에서도 182mg/L 정도의 유리 인산이 생성되었다. -
The effect of salinity on the nitrification efficiency of the nitrifier consortium was evaluated for the nitrification of saline wastewater. The nitrifier consortium, which was the activated sludge acclimated with ammonium as the only energy source, was used as the nitrifier for the salt acclimation. Airlift reactors for the nitrification of ammonia with increasing concentration in saline synthetic wastewater (35 g/I NaCD, and synthetic wastewater without salt as a control, were continuously operated with the nitrifier consortium for 43 days. The ammonia removal rate was about 23g ammonia-N/
$m^3$ /day in both the absence and presence of the salt. An accumulation of nitrite was observed in the saline nitrification reactor at an early period. However, the nitrite decreased to less than 1 mg/l after 39 days of operation. The salinity increased the acclimation time of the nitrifier consortium to obtain a stable marine nitrification system. However, the salt acclimated system showed the efficient removal of ammonia which was same as that without salt. -
RhodopseudolllOllas palustris P4 was studied for
$H_2$ production from glucose in batch culture. Important conditions studied include phosphate concentration, initial pH, temperature, glucose concentration, and gas-phase replacement. Optimal$H_2$ production was observed at 60 - 300 mM of phosphate and 7.8 - 8.6 of initial pH. The effect of culture temperature was negligible When glucose concentration increased from 0.1 to 5% (w/v),$H_2$ production increased up to 2% and remained constant thereafter. Intermittent purging of the reaction botlle with Ar gas stimulated the Hl production by alleviating the inhibition by$H_2$ . The maximum productivity was 111.1 ml$H_2$ /h-1. -
Citrobacter sp. Y19 was studied for
$H_2$ production from glucose in batch culture. Important conditions studied include phosphate concentration, temperature, glucose concentration, and gas-phase replacement. Optimal$H_2$ production was observed at 140 - 180 mM of phosphate and$36^{\circ}C$ . When glucose concentration increased from 0.1 to 5% (w/v),$H_2$ production increased up to 2% and remained constant thereafter. Intermittent purging of the reaction bottle with Ar gas stimulated the$H_2$ production by alleviating the inhibition by$H_2$ . The maximum productivity was observed to be 113.2 ml$H_2$ /h-1. -
Low-temperature adaptation and protection for environmental stresses were studied in the gram-negative soil bacterium Bradyrhizobium japonicum 61A101c. B. japonicum was more resistant to alcohol,
$H_2O_2$ , heat and freezing following a pretreatment at$4^{\circ}C$ , resulting in approximately 10 to 1,000 folds increased survival compared to mid-exponential-phase cells grown at an optimal temperature at$28^{\circ}C$ . This phenomena relate to the cold shock protein expressed when cells are exposed to a downshift in temperature. To confirm the presence of cold shock protein genes in B. japonicum, a PCR strategy was employed using a degenerate primer set, which successfully amplified a putative csp gene fragment. Sequence analysis of the PCR product(200bp) revealed csp-like sequences that were up to 96% identical to csp gene of S. typhimurium. -
The anaerobic bacterium Clostridium ljungdahlii was known to produce ethanol from CO,
$CO_2$ and$H_2$ In this research the production of ethanol at high concentration from carbon monoxide was studied. ethanol production using fed -batch, ceramic filter supported system, and 2-stage bioreactors were tested and optimized. -
이 연구에서는 가수분해효소인 Orientase 22BF를 5가지 당체에 흡착법을 사용해서 고정시키고 충전층반응기에 넣어 흡수도를 비교함으로써 고정화효율을 평가하였다. 결과는 다음과 같다. 최적 담체는 Celite IT 640, Duolite A568, 그리고 Silicagel 60이었으며, 담체의 최적조건은 pH 5.0, 온도
$50^{\circ}C$ 로 나타났다. 또한 이 연구에서 peptide solution을 얻기 위하여 난황 단백질을 사용하였다. -
Lignin peroxidase was produced by free cells of Phanerochaete chrysosporium YU in shaking-flask batch cuture. Without aerating, the maximum activity was 785U/L. As nitrogen source, ammonium tartrate was used for LiP production and 0.02% ammonium tartrate concentration showed the highest potential for LiP prodution.
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피마자유와 메탄올의 transesterification 반응 (methanolysis)에서 Novozym 435가 가장 좋은 활성을 나타냈다. Novozym 435의 경우 유기용매를 사용하지 않을 경우에도 좋은 활성을 유지하였고 사용되는 효소량에 따라 최적의 유기용매가 다르다는 것을 확인하였다. 0.5 wt% Novozym 435를 사용한 경우 DIPE를 사용하였을 매 가장 높은 활성을 나타내었으나, 1.0 wt% 의 경우에는 heptane을 이용하였을 때 가장 높은 활성을 보였다. Novozym 435를 이용한 피마자유의 methanolysis에서 methanol 에 의한 저해 반응이 나타나고 oil과 methanol의 몰 비 가 약 1:7.37 일 경우 최대의 ricinoJeic acid methyl ester 를 얻을 수 있었다. 1.0wt%의 Novozym 435를 이용한 methanolysis를 통하여 하루동안 피마자유로부터 ricinoleic acid methyl ester 를 86.1% 의 수율로 얻을 수 있었다.
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토양으로부터 특이적인 광학 이성질체에 활성을 갖는 두 효소원을 선별한 후, 동정하여 Pseudomonas sp. S34와 B. stearothermophilus JY144로 명명하였고, genecloning과 sequencing을 통해 유전자의 특성 및 관련효소들과의 유연관계를 규명하였다. 규명된 정보의 분석과 비교를 통해 ketoprofen ethyl ester에 활성을 갖는 효소들의 구조적 특성을 추론할 수 있었고, 이를 바탕으로 발현시스템을 구축하였다. 대량생산된 효소를 활용한 반응의 결과 높은 수율과 순도를 갖는 각각의 광학이성질체를 경제적으로 생산할 수 있었다.
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자연계로부터 분리된 FJ1의 환경변수 및 기질 특이성을 본 연구에서 살펴보았는데, 분리 균주 FJ1의 특성은 최적pH, 최적온도는 각각
$6{\sim}7$ ,$25{\sim}30^{\circ}C$ 이었다. 또한, 분리균주는 FJ는 Avicel, 섬유소페기물과 같은 결정성 섬유소물질의 분해에 유리함을 알 수 있었다. 본 연구에서는 cellulose의 분해에 관련된 효소를 분비하는 분리균주 FJ1의 환경변수 및 기질 특이성을 조사하였고, 이를 기본으로 하여 배양인자의 조절을 통한 최적의 효소생산 및 생산되어진 효소에 의한 섬유소 페기물(볏짚, 폐지, 음식물 쓰레기 등)의 당화 특성을 검토하고 있다. -
Porcine pancrease lipase를 aldehyde-silica에 in situ 상태에서 immobilization 할때의 최적 조건에 대하여 연구하였다. Feed 용액의 조성비율, 양, pH, 온도, 농도, 유속에 대하여 최적화하였으며 lipase의 activity를 측정 비교하였다.
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A laccase produced the Trametes sp. was immobilized on CNBr-activated Sepharose 4B(CS4B) and tested for repeated-batch and continuous decolorization of dye. After immobilization, the enzyme was active in wider pH and temperature range, and its heat stability was greatly improved compared to those of the free laccase. Immobilized laccase was efficient for both repeated-batch and contionuous decolorization.
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The mycelium of 3 edible mushrooms, Shizophyllum commune, pleurotus ostreatus, Tricholoma sp. was cultured in a liquid for the production of a fibrinolytic enzyme. Among them, Shizophyllum commune produced highest amount of the enzyme. The intramycelial production of the fibrinolytic enzyme by the culture of the Shizophyllum commune mycelium was approximately 6-fold higher than the extramycelial production. The carbon and nitrogen sources for the production of the enzyme were 1.5% corn steep liguor and 1.0% soytone, respectively, and optimal culture temperature and initial pH were
$25^{\circ}C$ and pH 6, respectively. -
Enterococcus faecalis was cultivated under oxidative conditions established by adding some oxidants. FAD and lipoic acid either stimulate the biosynthesis of benzoylformate reductase or stabilize the enzyme, while
$MV^{2+}$ enhance the biosynthesis of the oxidoreductase but destabilize it. Since$MV^{2+}$ destabilize the benzoylformate reductase, substituting FAD for$MV^{2+}$ as a redox mediator would be desirable. Production of (R)-(-)-mandelic acid by a coupled reaction between the enzymatic reaction using benzoylformate reductase and the electrocatalytic reduction under the conditions of 1.5 U LiDH$ml^{-1}$ , 0.2 mM FAD, and 0.3 mM$NAD^+$ is now performing. -
The enzymatic synthesis of conjugates of lysine and aspartic acid with D-glucose was studied. Optimase M-440 showed the very poor regioselectivity in the transesterification of
$N{\alpha}$ ,$N'{\varepsilon}-di-t-Boc-L-Lys-OTFE$ and N-t-Boc-L-Asp-diOTFE with D-glucose. The acylation of glycosidic -OH and primary -OH of D-glucose occurred. However, Optimase M-440 catalyzed only the acylation of primary -OH group in the transesterification of$N{\alpha}$ ,$N'{\varepsilon}-di-t-Boc-L-Lys-OTFE$ and N-t-Boc-L-Asp-diOTFE with${\alpha}-$ and${\beta}-methylglucopyranoside$ in high yields without any other transesterification. Optimase M-440 also discriminated carboxyl groups of N-t-Boc-L-Asp-diOTFE. -
Kinetic resolution of various racemic aromatic epoxides by newly isolated Aspergillus niger LK has been investigated, and enantioselectivity of whole-cell biocatalyst was analyzed. The epoxide hydrolase (EHase) of A. niger LK was cloned using RT-PCR. The sequence homology was compared with that of other microbial EHase and the gene for EHase was characterized at molecular level.
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The comparative study of enzymes that catalyze a similar reactions but have different substrate spectrum and/or stereospecificity is a powerful approach to understanding the reaction mechanism between the relative enzymes, and it was also an useful tool to cloning the related enzyme, without the typical cloning from DNA library of genomic pools. For this purpose, we conducted an approach that the comparison at the molecular and protein level of esterases, from various sources including a previously identified (S)-stereospecific esterase of Pseudomonas sp. ES1. As expected, we found an esterase family genes that shared a high similarity at the protein and genetic level in the identical genus Pseudomonad. The striking structural and biochemical identity strongly suggested the family genes to be an identical one. We, hence, aligned the family genes and designated a degenerated primer for PCR-cloning using six Pseudomonas strains as templates. As a result, a recombinant esterase from Pseudomonas fluorescens KCTC 1767 was cloned and high-level expressed with high selectivity to (R,S)-ketoprofen ethyl ester. The enzyme exhibited a high ester-hydrolyzing activity to (S)-ketoprofen but did not hydrolyzed the opposite stereoisomer. Further characteristics were discussed in our presentation.
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Cyclodextrin glucanotransferase (CGTase) (EC 2.4.1.19) use starch to produce cyclic maltooligosaccharides (cyclodextrins, CDs) which are of interest in various applications. To obtain a novel CGTase having high CD-forming activity,
${\beta}-cyclodextrin$ glucanotransferase$({\beta}-CGTase)$ from Bacillus firmus var. alkalophilus was modified through site-directed mutagenesis and constructed five mutants, H59T, H59Q, Y96M, 9O-PPI-93, and${\Delta}(148-154)D$ , respectively. Y96M and${\Delta}(148-154)D$ showed much higher level of conversion yields of starch into CDs from 28.6% to about 39% compared to wild-type${\beta}-CGTase$ , respectively, but 90-PPI-93 maintained similar convesion yields of starch to CDs. And their${\beta}-CD$ ratios to total CDs were not changed and maintained, and convesion yields to linear maltooligosaccharides of all mutants were not changed significantly. These results indicates that five mutations of${\beta}-CGTase$ from Bacillus firmus var. alkalophilus appears to be important roles for increase of overall CD production rather than change of its product specificity, especially. -
Pseudomonas sp. GRC3은 식물병원성 진균 P. capsici 에 대해 길항력을 가지며, 배양시 생성되는 가수분해 효소의 활성이 증가함에 따라 항진균력 또한 증가하여, 4일배양 시 균사 성장 저해율이 최대치를 기록하였다.
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PLE를 이용한 levofloxacin의 생산에서 기질 150 mM 사용의 경우 두배의 몰농도 로
${\alpha}-CD$ 를 사용하여 산물의 생산량을 3.7 배까지 증가시킬 수 있었다. 그러나 이 경우${\alpha}-CD$ 의 사용량이 많아 경제성이 떨어지는 단점이 있다. 이에 같은 몰농도로${\alpha}-CD$ 를 사용하고 pH에 변화를 주어 용해도를 향상시켜 보았다. 기질 100 mM의 경우 pH 5.6에서 같은 몰농도의${\alpha}-CD$ 를 사용한 경우${\alpha}-CD$ 를 사용하지 않은 것에 비해 4.4배의 수율의 증대가 있었다. -
Levofloxacin은 ofloxacin의 L형의 광학이성질체로 D형의 ofloxacin보다 뛰어난 향균활성을 갖는다. 본 연구에서는 광학선택성을 지닌 외래 효소를 재조합균주에서 발현시키고 고농도배양과 세포고정화를 통해 levofloxacin을 생산하였다. E. coli 고농도 배양을 수행하여 89 g/L의 세포농도를 얻었으며 IPTG 1 mM로 단백질 발현을 유도하여 levofloxacin 생산 반응에 사용할 때 최적 첨가시기를 결정하였다. 세포고정화를 위해서는 sodium alginate를 사용하였으며 1.5% 첨가시 가장 우수한 효소활성을 나타내었고 재사용시에도 효소활성과 광학선택성이 유지됨올 확인하였다.
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정제, 농축된 free CGTase 는 pH 6.0 - 7.0의 범위에서 안정하였으며,
$70^{\circ}C$ 정도의 고온에서도 안정한 특성을 가지고 있었으며, CGTase의 고정화를 위한 방법으로서 CNBr-activated sepharose 4B에 의한 고정화가 가장 높은 효율올 나타내는 것으로 결정되었다. 고정화의 최적조건은$30^{\circ}C$ , 60rpm, pH 6.0의 phosphate buffer 하에서 9 시간 동안 고정화하는 것이었고, CNBr-activated sepharose 4B를 이용한 고정화의 경우 실험에 사용된 다른 모든 이온교환 수지에서 얻어진 효율에 비해 월등한 효과를 보였다. -
Calcium stearate was produced by this method was purified and recovered through new method. Lipolase 100-T was used to produce calcium stearate from hydrogenated beef tallow. This process was optimized major factor of two, temperature and enzyme concentration. The temperature was optimized in
$60^{\circ}C$ and enzyme concentration was 0.6wt% of hydrogenated beef tallow. -
농작물 종자의 발아를 억제하는 미생물, Pseudomonas sp. F721을 자연계로부터 분리 및 동정하였다. 그리고 식물성장 호르몬에 의하여 발아억제물질이 유도되어 생산됨이 밝혀졌다. 분리된 균주의 최적 배양조건을 검토한 결과,
$35^{\circ}C$ , pH 9.0, 15Orpm, 48 hr, substrate 0.5% (w/v), strain 1.0% (v/v)이었다. 발아억제의 정도는 종자의 종류에 따라 차이가 있었다. 발아억제물질의 물리${\cdot}$ 화학적 안정성 검토결과 pH 2.0${\sim}$ 12.0,$-20{\sim}100^{\circ}C$ 에서 대하여 안정성을 가지고 있었다. 발아억제 물질은 발아 초기에 대조 시험보다 약 90% 이상 발아를 억제하였다. -
분자각인 막에 대한 선택적인 홉착을 알아보기 위해서 우리는 템플릿을 바꾸어 보기도 하고 중합방법과 세척조건을 다르게 하였다. 결과에서 우리는 템플릿 탈착에는 아세트산 10% 수용액으로 세척한 경우 가장 우수한 회수도를 보였다. 그러고 In-situ implanting method가 post implanting method에 비해 약 1.8 나 더 나은 선택 흡착성을 보였다.
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분자 각인 막의 선택적 홉착능을 향상시키기 위하여 막의 세척방법과 제조온도 및 분리용액의 농도를 변화시켜 보았다. 실협결과 10%의 아세트산 수용액으로 세척한 경우 막의 제조온도는
$30^{\circ}C$ 일 때, 분리용액의 농도는 0.002% 일 때 우수한 선택적 홉착능을 나타내었다. -
Ketoprofen racemate를 각 enantiomer로 분리하고자 이동상의 조성을 변화하여 실험을 수행한 결과, hexane과 t-BME의 비가 60/40(%v/v)인 경우 적합한 체류시간과 분리도를 얻을 수 있었으며, 이동상의 acetic aicd를 0.1%(v/v) 첨가한 경우 낮은 pH에서 분리가 효율적으로 일어났다. 또한, 시료의 농도를 변화시켜 실험을 수행한 경우, 2000ppm까지는 선택도에 큰 변화없이 분리를 수행할 수 있었으나, 농도가 1000ppm 이상인 경우 분리도가 1.00미만으로 낮은 값을 보였다.
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Iron is an essential nutrient for most organisms, which supplied to them in a protein-iron complex known as ferritin. Ferritins are multimeric proteins found in prokaryotes, plants and animals. They are consisted of spherical shell of 24 subunits defining a cavity of about 8nm in diameter, where an iron core is laid down. Expression of ferritin in recombinant E. coli at
$37^{\circ}C$ led to the accumulation of recombinant ferritin. Insoluble form of ferritin was separated from disrupted cells, followed by various primary separation steps with two kinds of buffers. Collected samples from the primary steps were purified by DEAE-cellulose gels packed in a column. The fractions from the DEAE column were assayed to gain the amount and the purity of ferritin by using HPLC and SDS-PAGE. -
유자과피의 향기성분 중 대부분을 차지하는 limonene은 추출물의 함량을 결정하는데 많은 영향을 준다. 일반적으로 Citrus속의 과실류의 향기 성분들 중 가장 많이 함유되어 있는 limonene의 경우 초임계 이산화탄소에 대한 용해도는 압력 140
${\sim}$ 150 bar, 온도$35{\sim}40^{\circ}C$ 일 때 최대이고 유자 또한 다량의 limonene을 함유한 과실류로서 초임계 이산화탄소 압력 2000 psi와 온도$40^{\circ}C$ 에서 향기성분 중 limonene의 추출율이 향상되어 함량이 786.6088 mg/g으로 최대로 나타났다. -
지방산제거방법으로 초임계 이산화탄소를 이용하고자 지방산의 초임계 이산화탄소에 대한 용해도률 조사하였다. 추출온도와 압력을 실험변수로 하여 각 지방산의 용해도를 측정한 결과
$35-50^{\circ}C$ , 80-120atm의 범위에서 초임계추출이 이루어졌으며, oleic acid의 용해도는 약 1.7x10-4 mole/mole of$CO_2$ 이었다. 당 에스테르의 효소적합 성공정으로 초임계법을 적용하였는 바, 반응시간 24시간 후 약 67%의 전환율을 얻을 수 있었다. -
본 연구에서는 말라리아 항원의 생물학적 대량 생산 공정을 디자인하기 위하여 자체 개발한 재조합 E. coli 시스템의 여러 가지 조업 조건들, 즉 균체 성장과 외래 단백질의 유도 발현에 영향을 미치는 초기 배지 pH, 유도 발현 이후의 조업 온도 및 타이밍 , 그러고 기간 등을 조사함과 동시에 최적 배양 전략을 탐색하였다.
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본 연구에서는 생분해성 제초제, 살충제, 광역학적 치료제로 이용되는 ALA의 대량 생산과 온라인 모니터링을 위하여 형질전환된 E. coli 시스템을 개발하고, ALA의 생산량에 영향을 미치는 배지, 온도 등의 배양조건을 살펴보았다.
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Silk proteins from Nephila clavipes are fibrous proteins containing repetitive sequences with both crystalline and amorphous domains. In order to obtain high-level production of silk protein, the synthetic genes had 16 contiguous units of the consensus repeat sequence of the silk protein were expressed in Escherichia coli BL21(DE3) under the strong inducible T7 promoter. For production of recombinant silk protein in large amounts, pH-stat fed-batch cultures were carried out. The recombinant silk protein was produced as soluble forms in E. coli, and the recombinant silk protein content was as high as 11% of the total protein. When cells were induced at
$OD_{600}$ of 60, the amount of silk protein produced was 6.49 g/L. After simple purification steps, 9.2 mg of silk protein that was more than 80% pure was obtained from a 50 mL culture, and the recovery yield was 26.3%. -
본 연구에서는 BC 생산균주인 KJ-1을 UV와 NTG mutagenesis를 통하여 초기에 주입된 glucose를 효과적으로 이용하여 cellulose 수율이 향상된 균주로 계량하였다. Mutant들 중 수율이 2배정도 향상한 균주에서는 cellulose를 비롯한 gluconic acid, 2-keto gluconic aicd, 5-keto gluconic acid의 비율이 parent strain과 차이를 보였고, 시간에 따른 acid 농도 분포를 살펴보면 수율이 증가한 원인 중에 mutant가 parent strain보다 합성한 acid를 효율적으로 이용하고 있다고 추론 할 수 있었다.
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Xanthomonas oryzae #5로부터 클로닝 된 CFTase 의 functional domain의 분석을 위해 CFTase의 recombinant deletion mutant를 구성하고, recombinant protein을 분리, 정제하였다. 분리, 정제한 recombinant protein의 활성을 측정한 결과 C-terminal이 deletion 된 mutant는 cyclization 반응이 소실 되었다. 이와 같은 결과로부터 CFTase의 C-terminal 은 cyclization 반응의 중요한 functional domain 이다.
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An efficient fermentation strategy for the high level production of ultra-high-molecular weight poly(3-hdyroxybutyrate) (PHB) was developed. Although the cell and PHA concentrations obtained by flask cultures at different initial pH (6.0 or 6.9) were almost same level, the molecular mass of PHB produced were quite different along with the initial pH. When a recombinant Escherichia coli XL1-Blue harboring pJC2 containing the Alcaligenes latus PHB biosynthesis genes was cultivated in flask culture (pH 6.0), the PHB having a very high molecular weight of 22 MDa could be produced while only below 1 MDa at initial pH 6.9. The ultra-high-molecular weight PHB could be synthesized to high concentration of 89.8 g/L resulting in the PHB productivity of 2.07 g/L-h by simple fed-batch culture. In this study, we report that PHB having various molecular mass can be produced by employing metabolically engineered E. coli strains harboring the plasmids of different copy numbers containing the A. latus phbCAB genes.
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Metabolically engineered Escherichia coli strains harboring a plasmid containing a novel artificial polyhydroxyalkanoate (PHA) operon consisting of the Aeromonas PHA biosynthesis related genes and Ralstonia eutropha reductase gene were developed for the production of poly(3-hydroxybutyrate-co-hydroxyhexanoate) [P(3HB-co-3HHx)] from dodecanoic acid. By applying stepwise reduction of dissolved oxygen concentration (DOC) during the fermentation, the final dry cell weight, PHA concentration, and PHA content of 79 g/L, 21.5 g/L, and 27.2 wt%, respectively, were obtained in 40.8 h, which resulted in the PHA productivity of 0.53 g/L/h. The 3HHx fraction slowly increased during the fed-batch culture to reach a final value of 10.8 mol%. The 3HHx fraction in the copolymer could be increased by three fold when the Aeromonas hydrophila orfl gene was co-expressed with the PHA biosynthesis genes.
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37종의 주요 대사관련 유전자를 triplicate로 사용하여 DNA microarray를 제작하여 라이신 생산균주의 포도당과 원당을 탄소원으로 하여 배양시기에 따른 대사특성을 분석하였다. 포도당과 원당 사용시 C3, C4 대사산물의 변환에 관련된 anaplerosis에 관여하는 유전자의 발현변화가 매우 중요함을 파악할 수 있었다. 또한 배양시기에 따라 매우 특이적인 유선자 발현 양상을 보임을 학인할 수 있었다.
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Transcriptome analysis was performed for the production of recombinant protein in E. coli using DNA microarray containing 2,850 genes including all functionally known and putative ones. Changes in transcriptome were analyzed qualitatively and quantitatively to provide their physiological and metabolic meanings.
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의약용 인간 단백질은 현재 여러 제약으로 인해 동물 세포에서 만들어지고 있다. 그렇지만 곤충세포 시스템의 문제점인 수율과 배양의 까다로움과 같은 단점들을 보완할 수 있는 곤충세포 시스템 개발의 필요성이 대두되고 있고 본 연구에서는 의약용으로 많이 생산되고 있는 erythropoietin (EPO)을 Drosophila S2 cell에서 발현하여 CHO cell 유래의 EPO와 비교하였다. 그 결과 CHO cell에서보다 더 작은 분자량을 갖는 EPO를 확인하였다.
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Proteomics is a formalized approach for obtaining a rapid snap-shot of the protein complement of a tissue, cell or cell component. Such an approach is powerful in that it allows a parallel assessment of temporal protein fluxes. This is an important concept in view of the dynamic nature of protein expression. Undoubtedly, changes in protein expression are essential in any study aimed at investigating cellular networks. In this study, we analyzed and compared the proteomes of recombinant E. coli strain before and after induction. Proteome expression patterns of recombinant E. coli were resolved on 2D-gels, and the variations in the relative expression level of particular proteins were examined using software-aided protein quantification tool. We observed above 800 spots on a 2D-gel using Melanie II software. Many proteins which involved in chaperones were significantly up-regulated in recombinant E. coli. Therefore, it could be concluded that the expression of recombinant protein in E. coli acted as a stress to the cells, which change cells ability to synthesize proteins and induced the expression of various protective proteins.
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Expression of the vhb gene encoding bacterial hemoglobin (VHb) from Vitreoscilla has been used to improve recombinant cell growth and enhance product formation under microaerobic conditions because of its ability to enhance oxygen use. We coexpressed GFP and VHb in Escherichia coli BL21 and W3110, and compared with GFP control which was not expressed VHb. We used nar oxygen-dependent inducible promoter for VHb expression. The GFP amounts in E. coli expressed VHb was about five fold higher than in the control Fluorescence intensity was increased about two fold.
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In this study, the nar promoter of E. coli was characterized to see whether the nar promoter cloned onto pBBR122 can be used as an expression promoter of gram negative microbes. For this purpose, a plasmid with lacZ gene expressing
${\beta}-galactosidase$ instead of the structural genes of nar operon in a gram negative host strain(Agrobacterium.tumefaciens) was used to simplify an assay of induction of the nar promoter. The following effects were investigated to find optimal conditions: methods of inducing the nar promoter, optimal nitrate concentration, maximally inducing the nar promoter, the amount of expressed${\beta}-galactosidase$ and induction ratio(specific${\beta}-galactosidase$ activity after maximal induction/specific${\beta}-galactosidase$ activity before induction). The following results were obtained from the experiments: the growth of Agrobacterium with E.coli nar promoter was not much affected by nitrate concentration in the shake-flask; induction of nar promoter was optimal when Agrobacterium was grown in the presence of 1% nitrate ion at the beginning of culture and when overnight culture was completely grown in the shake-flask before being transferred to other shake-flask; the amount of${\beta}-galactosidase$ per cell and per medium volume was maximal when Agrobacterium was grown under aerobic condition to$OD_{600}$ of 1.7; then the nar promoter was induced under microaerobic and anaerobic condition made by lowering dissolved oxygen level(DO). After 2-3h of induction in the YEP medium selected as a main culture medium, the specific${\beta}-galactosidase$ activity became about 17,000 Miller units in the fermentor cluture. -
The nar promoter of Escherichia coli was known to induce maximally under anaerobic or microaerobic conditions in the presence of nitrate. In this study, the nar promoter was tested to see whether the expression level of a reporter gene which fused lacZ gene at nar promoter's downstream, in the some gram negative host strains(Agrobacterium, Pseudomonas and Rhizobium). A nar promoter system(Combination of nar promoter and gram negative strain) was grown under aerobic conditions to absorbance at 600 nm of nearly 2.0 and then, the nar promoter was induced by lowering DO to 1-2% with alternating microaerobic and aerobic condition in the fermentor cultures, using different gram negative hosts. For a wild type nar promoter (pNW61), it was possible to maintain production of
${\beta}-galactosidase$ activity per cell(specific${\beta}-galactosidase$ activity) at 14,000, 9600, 45 Miller units in the presence of 1% nitrate. and for a nitrate - independent nar promoter (pNW618) at 12,000, 10,400 and 58 Miller units in the absence of nitrate ion, respectively. -
Experiments were accomplished to reduce the extent of proteolysis by simply controlling the culture conditions instead of the gene manipulation techniques. L-arginine and L-lysine were chosen as a protease inhibitor analogue With the assumption that they might act as the potential inhibitors against proteases involved in the rHSA proteolysis. The addition of arginine and lysine resulted in a considerable positive effect on the secreted rHSA production level.
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NADPH has been known as a regulating factor the biosynthesis of polyhydroxyalkanote(PHA), and the flux of NADPH for PHA biosynthesis could be enforced by the amplification of zwf gene encoding glucose 6-phosphate dehydrogenase. The recombinant plasmid pCZWF harboring PHA synthase, phbC from R. eutropha and zwf from E. coli were constructed, and were transformed to R. eutropha by electroporation. The biosynthesis of P(3HB-3HV) copolymer were carried out in transformant R. eutropha through the two-stage cultivation method using valerate as a precursor. The biosynthesis rate and PHA content of transformant R. eutropha harboring pCZWF were increased compared with transformant R. eutropha harboring only phbC. Especially, the molar fraction of 3HV was increased from 68% to 74% due to amplification of zwf gene. And the biosynthesis P(3HB-3HV) and P(3HB-4HB) carried out using propionate and
${\gamma}-butyrolactone$ as a precursor, respectively. But the rate, content, and molar fraction of biosynthesis copolymers were not influenced appreciably. This may be due to the reduced availability of NADPH. -
Pichia pastoris에서 생산된 rtLkn-1 은 농도에 따라 CFU의 colony 형성을 억제하였으며, 마우스와 인간 골수 세포에서 항암제에 의한 stem cell 및 progenitor cell의 사멸을 억제하였고 이것은 항암제가 작용하는 동안 세포 주기를 일시적으로 휴지기로 유도하였기 때문으로 사료된다.
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Human leptin is a 16kDa protein and is known to influence body weight control. It is composed of 146 amino acids. In this study, human leptin gene was obtained from homosapiens leptin mRNA using RT-PCR. And leptin gene was inserted into secretion vectors and Saccharomyces cerevisiae was transformed. In flask culture, Saccharomyces cerevisiae transformant showing high leptin expression titre was selected and with the best transformant, fed-batch fermentation and purification was optimized. As a result, about 2 g/L of leptin was expressed and the yield of purification was about 80%.
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Albumin is known to be used in many applications and to have huge market. Nowdays the importance of recombinant albumin is emphasized over albumin from serum because of elimination of viral disease problem. However for commercialization of recombinant albumin, high titre of expression level is prereguisite for economic feasibiility. Therefore in this study, sereval expression systems using different kinds of yeasts were tested and optimized and compared
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대두유의 유화전이에스테르화에 의한 바이오디젤의 생산기술을 연구개발함에 있어서 지방산메틸에스테르의 수율에 미치는 메탄올 몰비, 알칼리 촉매량, 유화제 첨가량 및 반응시간의 영향을 규명하고 유화전이에스테르화 공정의 반응조건을 최적화한 결과, 반응온도
$45^{\circ}C$ , 대두유에 대한 에탄올 몰비 1:6, 대두유에 대한 유화제의 첨가량 l(v/v)%에서 0.8wt% 수산화캄륨과 1.2wt% 소디움메톡시드로 대두유를 각각 30분과 50분간 전이에스테르화 하여$95{\sim}96%$ 수준의 총괄수율을 얻었다. -
This study was conducted to develop a new biomaterial to be used for skin whitening. The melanin elimination effect of chondroitin sulfate and phelinus linteus mushroom in rabbit back skin were evaluated. Rabbit dorsum was exposed to chronic UV irradiation(320nm) once daily for 30 days after initial melanin injection (100mg/kg). And then, chondroitin sulfate and phelinus linteus mushroom at dose of 0.7g for 30days were applied on the zone. The dorsal skin was histologically examined. Furthermore, we investigated free-radical extinction effect, antioxidation and tyrosinase activity inhibition effects. The histological study indicated that chondroitin sulfate and phelinus linteus mushroom decreasd melanine pigment significantly. As a result, chondroitin sulfate and phelinus linteus mushroom have a remarkable effect on the skin whitening by melanin elimination.
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The
$Ag^{2+}$ solution was constructed by supplying pure metal silver in filtrated distilled with constant voltage. The solution at the$Ag^{2+}$ concentration of 10 ppm showed specific activity against Gram positive and negative bacteria. More than 90% activity showed against Candida albicans ATCC 102321 at the same concentration. The addition of DASA,$Ag^{2+}$ and artemisia mixture, in the EVLN had same activity by comparison with chemical synthetic antiseptic. -
The intermolecular hydrogen bond between silk fibroin in aqueous solution facilitates gelation of silk fibroin. The dependence of gelation by the concentration of silk fibroin, pH and temperature was investigated. The gelation time of silk fibroin is decreased with increasing the concentration of glycerol and temperature within a limited range. The pH optimum for gelation found out to be 9. Hydrophobic additives were investigated to reduce gelation time.
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This study was designed to investigate the antioxidative activity of a substance isolated from. The antioxidative activity of procyanidine was higher than that of dl-tocopherol and BHA on low-density lipoprotein (LDL) oxidation by thiobarbituric acid reactive substance (TBARS). Procyanidine inhibited the copper-mediated oxidation of human LDL in a dose dependent manner with almost complete inhibition at
$60{\mu}g/mL$ . Procyanidine at a concentration of$80{\mu}g/mL$ in hibited oxidation of LDL induced by J774. LDL oxidized by copper-mediated or cell-induced oxidation was degraded at a much greater rate than native LDL. These results suggested the importance of further research to procyanidine in the investigation of atherosclerosis and free radical-induced injury. -
The rheological properties of exopolysaccharide(EPS-R) produced by marine bacteria Hahella chjuensis KCTC 2395 was investigated. EPS-R solution showed a characteristic non-Newtonian behavior fluid properties. In aqueose dispersions of EPS-R 1%, consistency index(K) and flow behavior index(n) were 1,410 cp and 0.73. EPS-R solution was pseudoplastic fluid by power-low model. Rheological propertie of EPS-R was found to be influenced by the concentration of salt, pH, temperature and ionic compounds.
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수계 미생물의 세포 농도 정도를 DST와 spectrophotometer를 이용하여 간편하고 빠르게 측정할 수가 있었다. 기존의 MPN와 MF의 방법은 노동집약적이며 false positive나 false negative의 확률이 높고 검출 시간도 하루이상 소요되는 단점이 있었다. 그러나, 세포 성장거동과 DST의 원리를 웅용하여 간편한 검출 시스템을 정량적으로 기술함으로써 쉽고 빠르게 수계 미생물의 농도를 측정하는 방법을 제시하였다.
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In this study a fiber optic biosensor has been developed to on-line monitor the concentrations of oxygen and glucose. The oxygen concentrations in solution and gas phase monitored by the fiber optic sensor has been compared with those by a dissolved oxygen electrode and an IR-type
$O_2$ analyzer. The fiber optic glucose sensor has been made by immobilizing glucose oxidase on the tip of the optic fiber and used to on-line monitor the concentration of glucose in a fermentation process. -
In the initial process of photosynthesis, a biological electron transfer system, photoelectric conversion occurs and then long-range electron transfer takes place very efficiently in one direction through the biomolecules. The metal/insulator/metal structured device consisting of GFP, viologen, cytochrome c hetero-thin film was presented based on the biomimesis. GFP, viologen, and cytochrome c was used as an electron sensitizer, a mediator, and an electron acceptor. Cytochrome c molecules and viologen molecules were deposited by Langmuir-Blodgett (LB) technique, and GFP molecules were adsorbed by self-assembly method (SAM). Surface morphology of hetero-thin film was analyzed by scanning tunneling microscopy (STM). Local photoswitching effects of a proposed photodiode were verified by current-voltage measurements using hybrid STM/I-V measurement system.
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이 실험은 특정 DNA를 검출 할 수 있는 새로운 방법을 제시하고 개발하려는 것이다. 이것은 geno-chromatography 분석방법이라고 하여 DNA capture probe를 membrane상에 고정하고 PCR을 통하여 증폭된 특정 유전자를 hybridization 반응을 이용하여 탐지하는 것이다. 이러한 개념을 식중독균의 일종인 Salmonella 균의 탐지에 적용하여 그 분석시스템의 성능을 확인 할 수 있었다.
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Phage antibody 생산방법은 유전자 조작에 의하여 phage coat에 항체를 발현시키는 방법이며 그 library를 이용하여 일반 hybridoma 방법에 의해 항체를 생산하기 어려운 성분 (예: 독성물질, 면역화가 잘 안되는 물질 등) 에 대해 적용할 수 있는 장점을 제공한다. 본 연구진은 Griffin.1 antibody library의 positive control을 통해 phage 표면에 항체가 발현되는 지의 여부를 ELISA test를 통하여 확인하였다. 또한 human serum albumin을 모델분석물질로 사용하여
$1{\sim}4$ 차까지의 bio-panning 을 실시하였고 각 단계에서 증폭된 phage를 가지고 ELISA test를 한 결과 신호가 점진적으로 증가하는 data를 얻을 수 있었다. 이것을 통해 phage library로부터 특정 항원에 대한 monoclonal antibody를 생산할 수 있다는 사실을 검증하였다. -
면역크로마토그래피 기술을 이용하여 동맥경화와 심근경색 발병을 진단하는데 매우 중요한 지표인 HDL-C 측정을 위한 현장의료용 진단시스템을 개발하였다.
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Free radicals cause many diseases and aging. In our body coexist useful and harmful bacteria. Some useful intestinal bacteria such as L. plantarum, B. adolescentis, B .bifidum, B. infantis, C. butyricum were presented positive growth in culture medium bearing natural products. L. plantarum was more effectively grown by mixed natural products of CORNI FRUCTUS+THEAE FOLIUM+COPTIDIS RHIZOMA+PAEONIA JAPONICA, B. adolescentis was BEIAMCANDA CHINENSIS+ANGELICAE GIGANTIS RADIX+EPIMEDII HERBA+PAEONIA JAPONICA, B. bifidum was NELUMBO NUCLFERA GAERTNER+THEAE FOLIUM+BEIAMCANDA CHINENSIS+CORNI FRUCTUS, B. infantis was THEAE FOLIUM+CHELIDONIUM MAJUS L.+ASTRAGALI RADIX+EPIMEDII HERBA, C. butyricum was EPIMEDII HERBA+PUERARIAE RADIX+NELUMBO NUCLFERA GAERTNER+PAEONIA JAPONICA,etc. These natural products will support an important role in bio-industry.
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For understanding physiology and metabolism under various culture conditions, combined analysis of transcriptome and proteome is attractable way. We have manufactured DNA microarray containing 2,850 genes including all functionally known and putative ones. In this study, we report analysis of transcriptome and proteome during the high cell density culture of E. coli by using DNA microarray and 2-DE. Fed-batch fermentation of E. coli was carried out by exponential feeding of nutrients until the maximum cell density reached 74 g dry cell weight/L (g DCW/L). Changes in transcriptome and proteome during the HCDC are analyzed qualitatively and quantitatively to provide their physiological and metabolic meanings.
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The preparation, characterization and drug release behaviour of hydrocortisone(HC) loaded levan acetate microparticles were investigated. Hydrophobic levan acetate was prepared by chemical modification of hydrophilic levan and micro particles were made by dialysis method or solvent evaporation method. The morphology of levan acetate was observed by SEM and drug release profiles were investigated at pH 7.4 and pH 1.2. Newly synthesised levan acetate can be used for carrier of drugs.
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The purpose of the present study is to find the optimal growth condition of Crypthecodinium cohnii. Using a design of experiments, it was found that the yeast extract was the most significant factor for cell growth. The effect of glucose was less than that of yeast extract and the effect of NaCl was negligible. The highest cell density, 1O.96g/L was obtained at the concentration of yeast extract 7.5g/L.
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약모밀(Houttuynia cordata)의 뿌리에서 추출한 ethanol, chloroform, ethylacetate, butanol 및 수용성 추출물의 항균활성을 9 종의 Gram 양성균과 13 종의 Gram 음성균에 대하여 disc diffusion 방법으로 조사하였다. Ethanol, ethylacetae, butanol 추출물은 B. megaterium C. xerosis, S. aureus, S. epidermidis 및 E.coli 에 대하여 항균활성을 나타내었고, chloroform과 수용성 추출물은 활성이 나타나지 않거나 미약하였다. 그러나 Ethylacetate와 butanol 추출물은 상대적으로 낮은 농도에서 강한 항균활성을 나타내었다.
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For the development of preferable immunosensor and protein chip, the viologen Langmuir-Blodgett (LB) multilayer was fabricated on the surface, and then protein A was adsorbed on the proposed viologen LB film by electrostatic attractive force. The Immunoglobulin G (IgG) labeled with fluorescence marker was self-assembled on the fabricated protein A film. The topographies of the deposited films were investigated by using atomic force microscope (AFM). The immobilization of IgG was verified by fluorescence spectrum. Such structures can be used as sublayers for various kinds of IgG immobilization toward immunosensors and protein chip.
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Radish추출물을 수용성과 지용성으로 나누어 추출하여 DPPH 저해율, SOD 활성율, Catalase 활성, collagen 함량변화를 측정한 결과, DPPH 저해율과 Catalase 활성은 수용성 추출물(81.0%, 175units/mg)에서 높게 나타났고, SOD 활성율에서는 지용성 추출물(92.3%)이 높게 나타났다. 콜라겐
$(21.45{\mu}g)$ 내의 pyridinoline의 함량은 control에 비해 수용성과 지용성 추출물을 첨가한 반응액에서 적었으며, 두 추출물을 비교해 봤을 때 큰 차이는 보이지 않았다. -
아급성 독성 시험으로부터, 미립구내의 레티노익 산을 기준으로 한 투여량이 100mg/kg 일때는 4마리의 치사 개체가 보이는 등의 심각한 독성 효과가 유발되었으며, 25 및 50mg/kg인 경우에 독성 효과가 거의 나타나지 않음을 관찰하였다. 50mg/kg의 투여량의 경우, 일부 동물에서 뼈골절 현상이 나타났지만, 이러한 독성효과는 항염증제를 같이 투여함으로써 극복될 수 있을 것으로 생각되어졌다. 따라서, 앞으로의 실험에서는 항염증제를 이용하여, 가능한 독성을 억제하연서, 보다 빠른 기간 내에 상태가 회복될 수 있도록 하는 연구를 행할 것이다.
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으름덩굴로부터 식품 보존재 개발을 위하여 실시한 연구 72hr동안 물 추출한 목통의 수용성 물질이 도시락 부패 및 식중독 유발균인 Bacillus subtills KCTC 1021 Bacillus cereus KCTC 1012에 항균력을 나타내있으며, Autoclave(
$121^{\circ}C$ 15min)를 할 경우 항균물질의 항균 활성이 더 높아짐을 확인할 수 있었다. 반연에 6hr 이상 열수 추출에서는 오히려 추출물의 항균력이 저하 되었다. -
청피와 모려에 다른 부재료를 사용하여 최적의 혼합비로 음료를 제조하기 위하여 모려에 대해 원소 분석한 결과 무기물 공급원으로 Ca가 18.8 ppm, Na가 23.8ppm으로 가장 많이 함유되었다. 청피에 대해 아미노산 분석한 결과 aspartic acid가 14290.431 pmol로 가장 많이 함유되어 있고, 필수 아마노산이 모두 함유되어 있었다. 이와 같은 분석 결과에 의해 음료를 제조한 결과 Citrus 1g, Amomum O.25g, Pueraria 0.5g, Ostrea 12g, citric acid 1g, sodium benzoate O.5g, aspartic acid 0.5g, raw sugar 90g 비율로 제조한 것이 관능검사를 실시한 결과 향기, 맛, 색 등 전반적으로 기호도 및 호감이 높은 것으로 나타났다. 일반분석한 결과 3종류간에 차이는 없었다.
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The cells of Lactobacillus plantarum MY4 isolated from the human feces were treated for 24 h in artificial bile after incubation for 2 h in artificial gastric juice and final number of the strain was reached to around
$3.1{\times}10^8$ CFU/ml. In test of API ZYM kit,${\beta}$ -glucuronidase or${\beta}$ -glucosidase were not produced by L. plantarum MY4. However,${\beta}$ -galactosidase were weakly produced by it, which they would be alleviated the lactose intolerance. L. plantarum MY4 were resistant to antibiotics such as nisin, tetracycline, streptomycin, rifamycin, doxycycline, roxithromycin, chloramphenicol, nystatin, erythromycin, ciprofloxacin and gentamycin. L. plantarum MY4 was affected by alcohol concentration up to 8%, but more than 16%, their growth was not affected significantly. L. plantarum MY4 was shown to inhibit the growth of Listeria monocytogenes ATCC 19111 completely within 24 h of incubation, which indicates its bactericidal nature. Thus, L plantarum MY4 show promise as a probiotic strain because of its characteristics. -
C-terminus specific immobilization often results in a increased structural stability resistant to various denaturation factors. In order to elucidate the immobilization effect on the c-terminus in molecular level, we made over 200 protein data set from Protein Data Bank(PDB), analyzed c-terminus structure of each protein, and investigated the structural relationship with the stabilizing factors such as hydrogen bond, ion pairs, cation pi, disulfide bond, solvation free energy, surface area, flexibility and so on.
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Zeta potential measurement not only can provide surface information on colloidal biomaterials but more importantly can be used in bioprocess control and products quality control. In this study, zeta potentials for intracrystalline proteins of each layers from oyster shell prepared in 1mM NaCl at different pH were measured. Also, in forming calcite crystals with intracrystalline proteins as an additive extracted from oyster shell, the zeta potentials were measured. These studies were performed to verify the primary role of intracrystalline proteins in controlling the formation, morphological development and crystallography of the biocomposite.
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This experiment was to determine the optimum conditions for D-sorbitol cyclization in the presence of p-toluenesulfonic acid(p-TSA) as acid catalyst before the esterification of sorbitol with fatty acids. The optimum conditions of hydration reaction to obtain maximum yield of 1,4-sorbitan were at
$130^{\circ}C$ , 200mmHg reduced pressure, after l50min and l%(w/w) p-TSA. In this condition the yield of 1,4-sorbitan was approximately 90%. -
This study was carried out to research on the heavy metal contents of domestic and imported medicinal herbs. The heavy metals contents in 116 samples of 51 types of medicinal herbs were measured by using a modified Monier-Williams, mercury analyzer and inductively coupled plasma spectrometer(ICP). The heavy metal contents of medicinal herbs were as follows; Hg: 0.010(domestic: 0.010, imported: 0.010), Pb: 0.380(0.311, 0.449), Cd: 0.080(0.101, 0.059), As: 2.085(1.845, 2.324), Mn: 31.564(33.844, 29.283), Zn: 15.436(18.703, 12.168), Cu: 3.406(3.374, 3.437), Fe: 134.944(108.327, 161.561) by ppm unit. The measured values of Pb and Cd of domestic and imported medicinal herbs showed lower levels than the recommended levels of those in medicinal herbs by WHO/PHARM (Pb: not more than 10 ppm, Cd: not more than 0.3 ppm). Finally, this results will be used as a basic data for the future legislation on the regulation and control of heavy metal contents of medicinal herbs.
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This study was carried out to investigate the sanitary conditions for foods providing in food service facilities such as convenience stores, flour stores, resting places in expressway and fast food stores in Kwang-ju city from May to September 2001. The samples were kimbabs and hamburgers, and were tested for indicative microorganism and food poisoning organism. and food poisoning organism.
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곤충병원성 선충으로부터 각각 공생박테리아를 분리하여 flask 상에서 7일간 배양하여 공생박테리아의 성장정도, 단백질 분해 효소의 생성, 배양상등액의 꿀벌부채명나방 유충에 대한 살충성 및 지방산 함량에 관한 연구를 수행한 결과 XR-PC 및 XR-MK의 성장 및 살충성이 가장 우수한 것으로 나타났으며 protease 활성은 XR-DR이 배양 4일째 최대 활성을 보였으며, 지방산 함량의 경우 XR-PC 및 XR-HY가 다른 종의 지방산 함량에 비해 12:0, 14:0, 13:0 iso, 16:1 cis 5, 17:0 cyclo에서 함량의 차이를 나타내었다.
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본 연구에서는 국내에서 분리된 곤충병원성 선충인 Steinernema carpocapsae종과 공생박테리아인 Xenorhabdus nematophilus종의 지방산을 분석하여 비교하였다. In vitro에서 수확된 곤충병원성 선충은 탄소 18개를 함유한 지방산이 가장 많은 것을 확인할 수 있었고, in vivo에서 수확된 곤충병원성 선충도 탄소 18개를 함유한 지방산이 가장 많은 것을 확인할 수 있었다. 하지만 그 다음으로 많은 지방산 성분이 in vitro에서 수확된 선충의 경우 탄소가 19개인데 비해 in vivo에서는 16개의 탄소를 가진 지방산인 것으로 나타나 차이점이 있는 것으로 확인되었다. 공생박테리아인 경우는 탄소의 수가 16개인 지방산이 가장 많이 함유된 것으로 나타났다.
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곤충병원성 선충인 S. carpocapsae에 대한 벼 물바구미의 field와 바프에서의 방제효과를 검정한 결과 표준처리구의 경우 부처리군에 비해 71%의 방제가를 보였으며, 2배처리구의 경우 74.2%의 방제가를 보였다. 바트에 처리한 경우에도 표준처리구의 경우 79.3%의 방제가를 보였으며, 2배처리구에서는 84.5%의 방제가를 보였다. 또한 공생박테리아인 Xenorhabdus spp.에 대한 바트에서의 벼 물바구미에 대한 선충의 방제가를 확인한 결과 무처리군에 비해 공생박테리아을 10mL 처리한 구에서는 33.3%의 방제가를 나타내었으며, 60mL의 공생박테리아를 처리한 구에서는 58.3%의 방제가를 보였다.
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Long-Term Starvation Induces the Viable-but-Nonculturable Condition in Lactobacillus crispatus KLB46In a previous study, we have isolated a number of lactobacilli from Korean women, and one of them (KLB46) was identified as Lactobacillus crispatus by 16S rRNA gene sequencing. For the ecological treatment of bacterial vaginosis (BV) cell suspension of L. crispatus KLB46 was instillated into BV patients. L. crispatus KLB46 was found to persist for several days in cell suspension with no nutrients. In this study, in order to assess the influence of starvation on physiological activity, we compared the viability and culturability of KLB46 following suspension in various buffer solutions. A pair of in situ fluorescent dye was used to assess viability (i.e. membrane integrity) and the culturability was examined by plate count assay. A rapid epifluorescence staining method using the LIVE/DEAD Bacterial Viability Kit
$(BacLight^{TM})$ was applied to estimate both viable and total counts of bacteria in cell suspension.$BacLight^{TM}$ is composed of two nucleic acid-binding stains ($SYTO\;9^{TM}$ and propidium iodide).$SYTO\;9^{TM}$ penetrates all bacterial membranes and stains the cells green while propidium iodide only penetrates cells with damaged membranes, therefore the combination of the two stains produces red fluorescing cells. Optimal staining conditions for$BacLight^{TM}$ were found to be with 0.0835M$SYTO\;9^{TM}$ and 0.05M propidium iodide for 15 min incubation at room temperature in dark. When cells were microscopically examined during 140 hours of starvation, the culturability decreased markedly while the viability remained relatively constant, which suggests that large fraction of KLB46 cells became viable but non-culturable (VBNC) upon starvation.