• Journal of Microbiology and Biotechnology
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• 제2권1호
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• pp.7-13
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• 1992

A moderately thermophilic, alkalophlic and powerful crystalline cellulose-digesting bacterium, Bacillus K-12, was isolated from filter paper wastes and found to be similar to Bacillus circulans or Bacillus pumilis, except for its ability to grow at a moderately high pH and temperature. The isolate grew at a pH ranging from 6 to 10 and at a temperature ranging from 35 to $65^{\circ}C$ and produced a large amount of cellulase components containing avicelase, xylanase, CMCase, and FPase when grown in avicel medium for 5 to 7 days at $50^{\circ}C$. The crude enzyme preparation from the culture broth hydrolyzed xylan, raw starch, pullulan and ${\beta}-1,3$ glucan such as laminarin. Furthermore, the enzyme hydrolyzed crystalline cellulose to cellobiose and glucose and had a broad pH activity curve (pH 6~9). The enzyme was stable up to $70^{\circ}C$.

• Applied Biological Chemistry
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• 제12권
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• pp.99-105
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• 1969

Trichoderma $(O_2-1)$의 조효소(粗酵素)를 Ethanol 및 Acetone 농도별(濃度別)에 따른 회수율(回收率)을 실험(實驗)한 결과(結果) 각(各) cellulase는 현저(顯著)한 차이(差異)가 나타났다. 즉(卽) Ethanol을 사용(使用)하였을 경우 ${\beta}-glucosidase$는 60% C.M.C분해효소(分解酵素), 여지붕괴(濾紙崩壞濾) 효소(酵素)는 80% 일때가 좋았고 Acetone을 사용(使用)하였을 경우 ${\beta}-glucosidase$는 60% 여지붕괴(濾紙崩壞濾) 효소(酵素)는 80%, C.M.C분해효소(分解酵索)는 90% 농도(濃度)일때가 좋은 결과(結果)를 나타내었다. 조정제(粗精製)한 Cellulase를 Silicagel, cellulose powder, Gauze를 사용(使用)한 column chromatography에 의(依)하여 분별(分別)란 결과(結果) 수치(數個)의 구분(區分)으로 분별(分別) 할 수 있었다. C.M.C 분해효소(分解酵索)와 Avicel 분해효소(分解酵索), ${\beta}-glucosidase$의 대부분(大部分)은 흡착(吸着)이 되지않고 유출(流出)되었으며, 대부분(大部分)의 여지붕괴효소(濾紙崩壞濾酵素)와 일부분(一部分)의 Avicel분해효소(分解酵索)는 흡착(吸着)되었다가 증류수(蒸溜水)로서 유출(流出)함으로씨 용출(溶出)되었다. 따라서 C.M.C 분해효소(分解酵索)와 여지붕괴효소(濾紙崩壞濾酵素)는 상이(相異)한 Cellulase 성분(咸分)임을 알았다. 또 C.M.C 분해효소(分解酵索)와 Avicel 분해효소(分解酵索)는 용출구분(溶出區分)에 있어 peak가 상이(相異)한 다른 구분(區分)에서 상대활성(相對活性)이 다르므로 역시 별개(別個)의 종류(種類)로 구분(區分)되었다. 또 여지붕괴효소(濾紙崩壞濾酵素)와 Cellulose powder (여지분말(濾紙粉沫)) 당화효소(糖化酵素)는 흡착구분(吸着區分)과 비흡착(非吸着) 구분(區分)으로 분별(分別)되니 사이(相異)한 Cellulase 성분(成分)이라고 생각된다. 따라서 Trichoderma viride $(O_2-1)$의 Cellulase는 적어도 3종이상(種以上)의 Cellulase 성분(成分)으로 되어 있다고 추찰(推察)된다.

• Membrane and Water Treatment
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• 제10권3호
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• pp.245-250
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• 2019

Prussian blue (PB) is well known for its excellent $Cs^+$ ions adsorption capacity. Due to the high dispersibility of PB in aqueous phase, composite materials imbedding PB in supporting materials have been introduced as a solution. However, building PB particles inside porous supporting materials is still difficult, as PB particles are not fully formed and elute out to water. In this study, we suggest layer-by-layer (LBL) assembly to provide better immobilization of PB on supporting materials of poly vinyl alcohol sponge (PVA) and cellulose filter (CF). Three different PB attachment methods, ex-situ/in-situ/LBL assembly, were evaluated using PB leaching test as well as $Cs^+$ adsorption test. Changes of surface functionality and morphology during PB composite preparation protocols were monitored through Fourier transform infrared spectroscopy and scanning electron microscopy. The results indicate that LBL assembly led to better PB attachment on supporting materials, bringing less eluting PB particles in aqueous phase compared to other synthesis methodologies, such as ex-situ and in-situ synthesis. By enhancing the stability of the adsorbent, adsorption capacity of PVA-PB with LBL improved nine times and that of CF-PB improved over 20 times. Therefore, the results suggest that LBL assembly offers a better orientation for growing PB particles on porous supporting materials.

• 한국대기환경학회지
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• 제25권3호
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• pp.179-187
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• 2009

This paper describes the field evaluation of a sampling and analytical method for the quantity of airborne hexavalent chromium ($Cr^{6+}$) in the industrial areas, such as Sihwa and Banwol. Ambient measurements were performed by using the cellulose filter during the four seasons (October 2006 to June 2007). The determination of hexavalent chromium was carried out by ion chromatography. Performance validations, including method detection limit, relative standard deviation, and recovery percent, were also investigated. The mean concentrations of $Cr^{6+}$ in Sihwa and Banwol were 0.767 and 0.796 $ng/m^3$, respectively, which are similar to those of other foreign industrial areas. The seasonal variations of $Cr^{6+}$ levels were not quite different, which implies that the chromium was continuously emitted from the industrial sources throughout the year. The concentration variations between total chromium and $Cr^{6+}$ have also shown the similar pattern, suggesting that these components originate from the same sources. The concentration of $Cr^{6+}$ was found to be 0.7 to 2.4% of the total chromium. From these results, the approach using the cellulose filter may be suitable to collect $Cr^{6+}$ in the ambient air.

• 한국연초학회지
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• 제2권1호
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• pp.8-16
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• 1980

Zeolite의 일종인 clinoptilolite를 담배필터 첨가제로 활용하는 연구를 하였다. 입자크기 30 $\pm$ 5 A.S.T.M. mesh의 clinoptilolite와 charcoal 1 : 1 (V/V)로 혼합하여 삼중필터의 cavity부분에 충진했을 때, 1. Cellulose acetate필터에 비하여 nicotine 35%, T.P..M.22%를 감소시켰으며, 2. Gas phase중 n-amyl alcohol등 aliphatic compound와 furan등 cyclic compound를 cellulose acetate filter에 비하여 60$\pm$ 5%를 감소시켰다. 3. Charcoal의 removal efficiency는 40-50% clinoptilolite의 10-20%에 비하여 큰 값이였지만 charcoal은 분자량이 큰 aromatic compound의 removal efficiency가 50$\pm$5%로서 aliphatic compound의 removal efficiency 40: 5%보다 큰 값이였음에 비하여 clinoptilolite는 alcohol과 ketone계열의 분자갹이 작은 화합물의 removal efficiency가 15-20%로 cyclic compounds의 removal efficiency 10-15%에 비하여 보다 큰 값이었다. 이 두물질의 gas phase성분의 흡착기능은 상호 보완적임을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제7권5호
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• pp.305-309
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• 1997

Bacillus stearothermophilus No. 236, an effective xylanolytic bacterium, produced an extracellular carboxymethyl cellulase when the strain was grown on xylan. The carboxymethyl cellulase was purified to homogeneity as judged by SDS-PAGE and zymogram, The carboxymethyl cellulase had a pI of 4.0, and a molecular mass of 95 kDa. The highest level of enzyme activity was observed at pH 6.5 and $60^{\circ}C$. The $K_m$, and $V_{max}$ values of the enzyme to carboxymethyl cellulose were 20.8 mg/ml and $0.63 {\mu}mole$/min/mg protein, respectively, The enzyme was found to act also on filter paper and xylan as well as carboxymethyl cellulose. Therefore, it is expected that this xylanolytic strain isolated from soil could be efficiently used for xylan biodegradation.

• Geomechanics and Engineering
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• 제34권2호
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• pp.125-138
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• 2023

To improve the understanding of infiltration characteristic of modified slurry and the support efficiency of filter cake in silty sand strata, the slurry infiltration (SI) and filter cake formation (FCF) were investigated in a laboratory apparatus. The water discharge and the excess pore pressure at different depths of silty sand strata were measured during SI. The relationship between permeability coefficient/thickness ratio of filter cake (k_c/ΔL) and effective slurry pressure conversion rate of filter cake (η) were analyzed. Moreover, the SI and FCF process as well as the modification mechanism of CMC (carboxymethyl cellulose) were clarified. The experimental results indicate the formation of only external filter cake in the silty sand strata. The slurry particles obtain thicker water membrane after being modified by CMC, which blocks partial water path in filter cake and decreases the water discharge significantly. The silty sand excavated from tunnel face also contributes to the water discharge reduction. The k_c of the external filter cake ranges from 3.83×10^-8 cm/s to 7.44×10^-8 cm/s. The η of the external filter cake is over 96%, which decreases with increasing k_c/ΔL. A silty sand content within 10% is suggested during construction to ensure the uniformity of the filter cake.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1178-1188
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• 2014

In this study, the yeast Pichia pastoris was genetically modified to assemble minicellulosomes on its cell surface by the heterologous expression of a truncated scaffoldin CipA from Clostridium acetobutylicum. Fluorescence microscopy and western blot analysis confirmed that CipA was targeted to the yeast cell surface and that NtEGD, the Nasutitermes takasagoensis endoglucanase that was fused with dockerin, interacted with CipA on the yeast cell surface, suggesting that the cohesin and dockerin domains and cellulose-binding module of C. acetobutylicum were functional in the yeasts. The enzymatic activities of the cellulases in the minicellulosomes that were displayed on the yeast cell surfaces increased dramatically following interaction with the cohesin-dockerin domains. Additionally, the hydrolysis efficiencies of NtEGD for carboxymethyl cellulose, microcrystal cellulose, and filter paper increased up to 1.4-fold, 2.0-fold, and 3.2-fold, respectively. To the best of our knowledge, this is the first report describing the expression of C. acetobutylicum minicellulosomes in yeast and the incorporation of animal cellulases into cellulosomes. This strategy of heterologous cellulase incorporation lends novel insight into the process of cellulosome assembly. Potentially, the surface display of cellulosomes, such as that reported in this study, may be utilized in the engineering of S. cerevisiae for ethanol production from cellulose and additional future applications.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.260-263
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• 2000

대량발효 후 미세여과막과 MWCO 100K, 50K의 한외여과막을 이용한 막분리시스템을 적용하여 MTGase를 분리한 결과 pore size 1.6, $0.7\;{\mu}m$의 cellulose fiber 재질의 예비여과막과 $0.45\;{\mu}m$ cellulose acetate재질의 미세여과막을 이용하여 얻어진 분리액을 MWCO 100K와 50K를이용하여 농축시킨 결과 enzyme의 농도가 1.29 units/ml, 효소 비활성도는 약 0.2 units/mg protein 으로 나타났으며 초기 배양액에 비해 3.7배의 농축효과를 보였다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.95-98
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• 2006

Filtration by fibrous filter is one of the Principle methods used for removing pollutant particles in the liquid. Because of the increasing need to protect both human health and valuable devices from exposure to fine particles, filtration has become more important. Filters have been developed with modified surface charge characteristics to capture and adsorb particles by electrokinetic interaction between the filter surface and particles contained in water. The main purposes of this study are to develop and evaluate the performance evaluation of the apparatus for making a positively charged porous filter media and to analyze the surface characteristics of the filter media for capturing negavitely charged contaminants mainly bacteria and virus from water. The experimental apparatus consists of a mixing tank, a vacuum pumping system, a injection nozzle, a roller press and a controller. The filter media is composed of glass fiber(50-750 nm), cellulose($10-20{\mu}m$) and colloidal charge modifier. The characteristics of filter media is analyzed by SEM(Scanning Electron Microscopy), AFM(Atomic Force Microscopy) and quantified by measuring the zeta potential values.