• 한국미생물·생명공학회지
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• 제50권3호
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• pp.436-440
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• 2022

본 연구에서는 염색체가공기술을 이용하여 xylan으로부터 다양한 대사산물을 생산할 수 있는 유전자를 도입한 효모인 공염색체를 구축하였다. 효율적인 염색체가공기술인 PCS법을 이용하기 위해 염색체 splitting에 필요한 splitting fragment (DNA module)를 각각 제작하였고, xylan 대사에 관여하는 유전자군을 가진 YKY164 균주에 형질전환하였다. 두번의 염색체 splitting에 의해 1,124 kb의 효모 7번염색체는 887 kb-YAC, 45 kb-mini YAC와 198 kb-YAC로 가공되었으며, 총 18개의 염색체를 가진 YKY183 균주를 구축하였다. 염색체가공을 위한 splitting efficiency는 50-78%였으며, 45 kb-mini YAC 상에 있는 외래유전자의 발현 및 효소활성은 염색체가공 전과 비교하여 유의미한 변화 및 저하는 관찰되지 않았다. 또한 생산된 재조합효소에 의한 xylan의 분해산물을 확인하였으며, 160 generation 동안 미니 효모인 공염색체는 염색체의 결실없이 안정적인 mitotic stability를 유지하였다.

• 한국가금학회지
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• 제28권3호
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• pp.245-257
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• 2001

가축사육이 집단화되면서 가축배설물의 축적은 집중화 현상을 초래하게 되었고 또 계속적인 분뇨 분비물의 유출은 환경공해의 요인이 되고 있으며 이는 공공의 걱정거리로 대두되고 있다. 가축분뇨 중에서 질소와 인이 환경공해요인이 되는 가장 중요한 영양소이지만 가축이나 축산시설물에서 발생되는 냄새 역시 공해의 요인이 되고 있다. 급여되는 사료의 영양소효율을 높이는 길이 환경공해를 감소시키는 방법이다. 가장 많은 실험은 닭과 돼지를 대상으로 하여 이루어졌다. 사료첨가제의 이용, 사양방법의 수정 등으로 사료중의 영양소 이용성을 높임으로서 질소와 인의 배출감소는 물론 냄새와 분의 건물함량을 줄일 수 있었다. 1) 합성아미노산 제제를 사료 중에 첨가하고 단백질 수준을 감소시켰을 때 육계의 경우 10∼27%의 질소배출을 기대할 수 있었으며 산란계의 경우 18∼35%, 돼지의 경우 62%, 돼지에서 생성되는 냄새를 9∼43%까지 감소시키는 효과를 기대 할 수 있었다. 2) 사료 중에 효소제를 첨가하였을 때 육계 분의 건물함량을 12∼15% 감소시킬 수 있었다. 3) phytase를 첨가할 경우 분으로 배설되는 인의 함량은 양계의 경우 25∼35%,돼지의 경우 9∼43%까지 감소가 가능했다. 4) 성장촉진제를 이용할 경우 돼지에서 질소의 배설 양을 5∼30% 감소시킬 수 있었으며 냄새는 53∼55%까지 감소가 가능했다. 5) 사료배합을 요구량에 가깝게 하여 급여하였을 때 양계나 양돈의 경우 질소와 인은 각각 10∼15% 감소를 기대 할 수 있었으며 돼지의 냄새는 28∼79%까지 감소가 가능했다. 6) 기별 사양을 철저히 실시함으로서 양계와 양돈의 경우 질소는 10∼33%, 인산은 10∼13%, 그리고 성장 비육돈의 경우 49∼79% 감소를 기대 할 수 있다. 7) 닭이나 돼지의 사료를 배합시 소화율이 높은 곡류를 이용하면 질소와 인의 배설을 5% 감소시킬 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권5호
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• pp.621-628
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• 2012

The FAT-1 protein is an n-3 fatty acid desaturase, which can recognize a range of 18- and 20-carbon n-6 substrates and transform n-6 polyunsaturated fatty acids (PUFAs) into n-3 PUFAs while n-3 PUFAs have beneficial effect on human health. Fat1 gene is the coding sequence from Caenorhabditis elegans which might play an important role on lipometabolism. To reveal the function of fat1 gene in bovine fetal fibroblast cells and gain the best cell nuclear donor for transgenic bovines, the codon of fat1 sequence was optimized based on the codon usage frequency preference of bovine muscle protein, and directionally cloned into the eukaryotic expression vector pEF-GFP. After identifying by restrictive enzyme digests with AatII/XbaI and sequencing, the fusion plasmid pEF-GFP-fat1 was identified successfully. The pEF-GFP-fat1 vector was transfected into bovine fetal fibroblast cells mediated by Lipofectamine2000$^{TM}$. The positive bovine fetal fibroblast cells were selected by G418 and detected by RT-PCR. The results showed that a 1,234 bp transcription was amplified by reverse transcription PCR and the positive transgenic fat1 cell line was successfully established. Then the expression level of fat1 gene in positive cells was detected using quantitative PCR, and the catalysis efficiency was detected by gas chromatography. The results demonstrated that the catalysis efficiency of fat1 was significantly high, which can improve the total PUFAs rich in EPA, DHA and DPA. Construction and expression of pEF-GFP-fat1 vector should be helpful for further understanding the mechanism of regulation of fat1 in vitro. It could also be the first step in the production of fat1 transgenic cattle.

• 한국식품영양과학회지
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• 제22권3호
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• pp.255-261
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• 1993

두부 제조공정 중의 부산물인 비지의 효율적인 이용을 위하여, 원료 대두 중량의 10%에 해당하는 건조비지를 첨가시킨 두부를 제조하여 이의 영양적 품질을 검토하였다. 일반성분은 수분의 경우 건조비지 첨가 두부가 80.6%, 일반 두부가 77.5%로써 비지 첨가 두부가 다소 높았으며 단백질의 함량은 건조비지 첨가 두부와 일반 두부 각각 38.5%, 45.8%였으며, 지질의 함량은 각각 34.3%, 26.9%로써, 단백질과 지질 함량이 낮은 건조비지 첨가로 인해 일반 두부에 비해 건조비지 첨가두부가 낮은 함량을 보였다. Trypsin inhibitor (TI) 함량은 비지의 경우 잔존량이 6.9 (mg/g시료)정도였고, 건조비지의 경우에도 거의 비슷하였다. 건조비지 첨가두부에는 원료 대두에 있었던 TI의 12% 정도만 남아있었다. 단백질의 효소소화율 (enzyme digestibility)은 비지, 건조비지 각각 87%, 86% 정도로 높았고 건조비지 첨가 두부도 일반 두부와 거의 동일한 91% 정도였다. 효소소화율은 TI함량이 저하함에 따라 역상관관계를 가지면서 상승하였다. 구성 아미노산 조성은 일반 두부와 건조비지 첨가 두부는 거의 차이가 없었으며, 총아미노산에 대한 필수 아미노산의 비율은 일반 두부가 40.4%, 비지첨가 두부가 40.6%였으며, lysine 함량이 높은 건조비지로 인하여 건조비지 첨가 두부는 lysine의 보충 효과가 있었다. 단백품질을 Computed Protein Efficiency Ratio (C-PER)로 계산할 때 일반 두부는 1.95, 비지 첨가 두부는 1.4였으나 Discriminant Computed Protein Efficiency Ratio (DC-PER)로 계산할 때는 오히려 비지 첨가 두부경우가 높았다. 여러 연구자들의 대두가공품에 대한 생체실험 결과와 비교할 때 일반 두부를 제외하고는 두유, 비지 및 비지첨가두부의 영양평가는 DC-PER 방법이 유리한 것으로 생각되었다.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2803-2808
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• 2014

High potential and fast electron transfer of a cathode mediator are significant factors for improving the performance of biofuel cells. This paper reports the first synthesis of a cathode redox polymer that is a coordination complex of poly (acrylic acid-vinylpyridine-acryl amide) (PAA-PVP-PAA) and [Os(4,4'-dicarboxylic acid-2,2'-bipyridine)$_2Cl_2]^{/+}$ ($E^{\circ}=0.48V$ versus Ag/AgCl). Bilirubin oxidase can be easily incorporated into this polymer matrix, which carried out the four-electron oxygen under typical physiological conditions (pH 7.2, 0.14 M NaCl, and $37^{\circ}C$). This new polymer showed an approximately 0.1 V higher redox potential than existing cathode mediators such as PAA-PVI-$[Os(dCl-bpy)_2Cl]^{+/2+}$. In addition, we suggest increasing the polymer solubility with two hydrophilic groups present in the polymer skeleton to further improve fast electron transfer within the active sites of the enzyme. The maximum power density achieved was 60% higher than that of PAA-PVI-$[Os(dCl-bpy)_2Cl]^{+/2+}$. Furthermore, high current density and electrode stability were confirmed for this osmium polymer, which makes it a promising candidate for high-efficiency biofuel cells.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.370-373
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• 2000

In this work, an extractive membrane bioreactor containing coulture broth of Burkholderia cepacia G4 PR1 constitutively expressing the TCE-degrading enzyme, tolune-ortho-monooxygenase(TOM), was used for the degradation of TCE. The membrane bioreactor operates by seperating the TCE-containing waste gas from the aerated biomedium, by which the air-stripping of TCE without degradation was overcome that could occur in conventional aerobic biological treatments of TCE-contaminated waste gases. This was achieved by a silicone rubber membrane which was coiled around a perspex draft tube. TCE from the gas phase diffuses across the silicone rubber membrane into microbial culture broth that was continuously fed from a separate aerobic CSTR. Therefore, TCE degradation occured without the TCE being directly exposed to the aerating gas stream. Of the TCE supplied to the membrane bioreactor, 72.6% was biodegraded during the operation of this system. To construct a mathematical model for this system, parameters describing microbial growth kinetics on TCE were determined using a CSTR bioreactor. Else parameters used for numerical simulation were determined from either indepedent experiments or values reported in the literature. The model was compared with the experimental data, and there was a good agreement between the predicted and the measured TCE concentrations in the system. To achieve a higher treatment efficiency, various operating conditions were simulated as well.

• 한국의류산업학회지
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• 제2권4호
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• pp.339-345
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• 2000

The effects of protease and/or lipase on the removal of protein soil and oily soil were investigated in this study. Cotton, rayon, nylon, and PET fabrics were soiled by padding of fresh bovine blood and spotting of mixed artificial sebum evenly. The soiled fabrics were aged at $130^{\circ}C$ for 30 minutes. The fabrics were washed by using Terg-O-Tometer at various conditions. Protease and/or lipase were added in the alcohol ethoxylate (AE) detergent solution. The removal efficiency was evaluated by analysis of protein and/or oil on the fabrics before and after washing, respectively. The detergency of protein and/or oil on the fabrics was discussed with enzyme concentration, washing time, washing temperature, pH of washing solution and fiber characteristics. The hydrolysis of protease improved effectively the removal of oil as well as protein by increasing removal of protein-oil mixed soil at the same time. The effect of lipase added detergent solution was slightly shown on the removal of oil and/or protein. The removal of mixed soils from cotton fabrics was very low because of large amount of residual soils caused by the physical characteristics of cotton fiber.

• Journal of Microbiology and Biotechnology
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• 제6권1호
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• pp.36-42
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• 1996

The production of sorbitol by permeabilized cells of Zymomonas mobilis immobilized in $\kappa$-carrageenan was investigated. Cetyltrimethylammoniumbromide (CTAB) permeabilized cells were treated with glutaraldehyde prior to immobilization for cross-linking of enzymes, glucose-fructose oxidoreductase (GFOR) in cells. Rigidity of the immobilized beads was increased two-fold with 90$\%$ conversion efficiency by the additions of 40$\%$ (w/v) polyols (glycerol 25 g + propylene glycol 15 g) to 60$\%$ (w/v) distilled water containing 2.5$\%$ (w/v) $\kappa$-carrageenan as a final concentration, prior to immobilization. $\kappa$-Carrageenan beads entrapping permeabilized cells were dried to improve bead rigidity and storage stability. During s6mi-batch process for 72 h with dry beads, there was an improvement of the loss of enzyme activity (less than 10$\%$). In batch process, the kinetic results of $K_m.fructose$ value for the free cells, wet beads and dry $\kappa$-carrageenan beads were 71.7, 72.4 and 116.7 g/l, respectively. Higher productivity was obtained with two-stage continuous packed bed reactors with both wet and dry $\kappa$-carrageenan beads at 25.00 and 21.15 g/l/h, respectively, when measured at second stage.

• 펄프종이기술
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• 제48권3호
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• pp.37-43
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• 2016

Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.

• 한국미생물·생명공학회지
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• 제3권1호
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• pp.17-22
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• 1975

한국산 도토리의 이용을 위하여 도토리 속에 함유되어 있는 8∼9%의 tannin을 제거하는 방법으로서 1. 강역 tannase생성균주로서 Aspergillus niger sp. 를 부패한 도토리로부터 분이하였고 2. 한국농가에 고내로 전수되어온 방법중에서 도토리 분말을 수세, 교반, 정치해서 상단액을 버리는 tannin용해법이 24시간내에 tannin사양을 0.18%까지 줄일 수 있어서 가장 경제적이고 결과가 크다는 것을 알았다. tannin을 제거한 도토리 분말의 성분중 단백질의 anino acid조성은 단일식품으로서는 비교적 많은 종유의 필수아미노산이 함유된 것을 알았다. 본실험은 74연도 문교부 연구조성김으로 이루워진 것이다.