• Parasites, Hosts and Diseases
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• 제21권1호
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• pp.49-57
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• 1983

The distribution and Properties of branched chain amino acid aminotransferase (EC 2.6. 1.42) was investigated in adult Fasciola hepatica. Fascicla hepatica was fractionated by differential centrifugation into nuclear, mitochondrial and cytosolic fractions. The activity of branched chain amino acid aminotransferase was measured by the method of Ichihara and Koyama (1966) . Isozyme patterns of this enzyule was also examined by DEAE-cellulose column chromatography. The results obtained were as follows; 1. The activity in homogenate was found to be 12.69 units/g wet tissue. The activity of this enzyme was relatively high compared with those in rat tissues. 2. The distribution of branched chain amino acid aminotransferase in the subcellular organelles showed that 87.8% of the activity was in cytosolic, 10.9% in mitochondrial and 1.3% was in nuclear fraction. 3. Cytosolic fraction of Fasciola hepatica contained Enzyme I, but not Enzyme II and III, of branched chain amino acid aminotransferase. Ensyme I was eluted by 50mM phosphate buffier from DEAE-cellulose column and catalyzed the transamination of all three branched chain amino acids. 4. The Enzyme I was purified about 22-folds increase in specific activity after chromatography on DEAE-cellulose. 5. The best substrate among three amino acids (leucine, isoleucine and valise) was L-isoleucine. 6. The optimal temperature of Enzyme I was $45^{\circ}C$ and the optimal pH was 8.2. 7. The Km value for leucine of Enzyme I was 4.17 mM. 8. The Km values for a-ketoglutarate and pyridoxal phosphate of Enzyme I were 0.41mM and $4.76{\times}10^{-3}{\;}mM$, respectively.

• 한국식품과학회지
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• 제16권3호
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• pp.322-328
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• 1984

Pizopus oryzae가 생산(生産)하는 glucoamylase를 유안(硫安)및 acetone 분획(分劃)과 이온교환수지의 column chromatography에 의하여 정제(精製)하였다. 즉(卽) 조효소액(粗酵素液)을 유안분획(硫安分劃) acetone 분획(分劃), DEAE-cellulose column chromatography, CM-cellulose column chromatography에 의(依)하여 두가지형(型)의 glucoamylase를 분리정제(分離精製)하였으며 이들을 각각(各各) glucoamylase I과 II라고 하였다. Glucoamylase I과 II의 Specific activity는 각각(各各) 157.6U/mg protein (조효소액(粗酵素液)의 37.5배(倍)) 164.7U/mg protein (조효소액(粗酵素液)의 39.2배(倍)) 이었고 수율(收率)은 각각(各各) 4.3%, 3.8%이었다. Glucoamylase I과 II는 polyacrylamide disc gel electrophoresis와 SDS-polyacrylamide gel electrophoresis에 의(依)하여 각각(各各) 단일(單一)한 band를 나타내었고 이 단백질(蛋白質) band는 옥도염색(沃度染色)에 의(依)해 glucoamylase 활성(活性)을, PAS염색(染色)에 의(依)해 glycoprotein임을 확인(確認)하였다.

• Journal of Nutrition and Health
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• 제31권6호
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• pp.991-998
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• 1998

The effects of indigestible dextrin on serum lipid and glucose concentrations, large intestinal functions, feces states, and gastrointestinal transit time were studied with 90 male Sprague-Dawley rats. Diets contained 0.5% cellulose(0.5CL control), 10% cellulose(10CL), and 10% indigestible dextrin I (10ID-I), respectively and were fed to the rats for 3 weeks. Serum cholesterol and LDL-cholesterol concentrations were lower in rats fed the 10ID-I diet. Serum triglyceride concentration was lower in rats fed the 10CL diet. Cecal content and cecum weight significantly increased in the rats fed the 10ID- I diet. Cecal pH of the rats fed the 10ID-I diet was lower than that of the rats fed the 0.5CL diet. Changes of fecal output were not observed in case of 0.5CL and 10ID-I diets but a significant increase was observed in the case of 10CL. Gastrointestinal transit time of 10ID-I was the longest among the three diets. These results demonstrate that indigestible dextrin delivered to the cecum was not digested and increased the cecal mass. Indigestible dextrin improves colonic health of rats by inducing low pH of the cecum. (Korean J Nutrition 31(6) 991-998, 1998)

• 한국미생물·생명공학회지
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• 제46권2호
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• pp.120-126
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• 2018

환경친화적으로 항균성이 부여된 상처치료용 BC 드레싱을 개발하기 위한 기초연구로서, 은 이온에 대해 내성이 있으면서 은 나노입자를 생합성할 수 있는 초산균을 분리 및 동정하였다. 나아가 실험균주에 의한 BC 생산 조건을 조사하였다. 부패된 포도껍질로부터 분리된 G7 균주는 0.1 mM $AgNO_3$ 존재 하에서 생육할 수 있었으며, 16S rRNA 유전자의 염기서열 분석에 의거하여 Acetobacter intermdius로 동정되었다. 탄소원으로 2% glucose, 질소원으로 2% yeast extract, 보조탄소원으로 0.115% acetic acid가 함유된 배지에서 BC 생산량이 최대였다. 최적배지에서 생성된 BC의 구조적 특성을 FT-IR 및 XRD를 사용하여 조사한 결과, 생성된 BC는 전형적인 천연 cellulose와 동일한 cellulose I인 것으로 확인되었다. G7 균주를 0.1 mM $AgNO_3$ 가 함유된 최적 배지에서 배양한 결과, 배양액의 색깔이 적갈색으로 변하였으며, 이것은 은 나노입자가 생성되었음을 의미한다. 은 나노입자의 합성유무를 UV-Vis 스펙트럼 분석에 의하여 확인한 바, 425 nm에서 은 나노입자의 고유한 흡수스펙트럼이 관찰되었다. 또한, 생성된 BC를 주사전자현미경으로 관찰한 결과, 표면과 기공에 은 나노입자가 생성되어 있음을 재확인하였다.

• Journal of the Korean Wood Science and Technology
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• 제22권3호
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• pp.26-31
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• 1994

To provide further information for reutilization of the waste wood obtained after cultivating oak mushroom in Kangwon-do, the crystal structures of the waste wood were investigated and compared to those of normal woods by a series of x-ray diffraction analysis. The results obtained are as follows: 1. An x-ray diffraction diagram of cultivated wood for 5 years was same as that of typical cellulose with some orientation of cellulose crystallites, but that of cultivated wood for 8 years a random. 2. Crystallinity indices in normal and cultivated woods for 5 years ranged from 57% to 60%. In the cultivated wood for 8 years, however, the value showed about 40%. 3. Crystallite widths of cultivated woods for 5 years and for 8 years were 3 nm and 2.5 nm, respectively. 4. Intensity ratios of equatorial and meridional layers did not show any significant differences. From the above results, it is clear that the waste wood obtained after cultivating oak mush room for 5 years showed basically same crystal structures with normal wood. Therefore, we think that the waste wood may be used available for cellulosic material instead of normal wood.

• Current Research on Agriculture and Life Sciences
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• 제31권4호
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• pp.250-255
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• 2013

As a renewable nanomaterial, cellulose nanocrystal (CNC) isolated from wood grants excellent mechanical properties in developing high performance nanocomposites. This study was undertaken to compare the reinforcing efficiency of two different CNCs, i.e., cellulose nanowhiskers (CNWs) and cellulose nanofibrils (CNFs) from hardwood bleached kraft pulp (HW-BKP) as reinforcing agent in polyvinyl alcohol (PVA)-based nanocomposite. The CNWs were isolated by sulfuric acid hydrolysis while the CNFs were isolated by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation. Based on measurements using transmission electron microscopy, the individual CNWs were about $6.96{\pm}0.87nm$ wide and $178{\pm}55nm$ long, while CNFs were $7.07{\pm}0.99nm$ wide. The incorporation of CNWs and CNFs into the PVA matrix at 5% and 1% levels, respectively, resulted in the maximum tensile strength, indicating different efficiencies of these CNCs in the nanocomposites. Therefore, these results suggest a relationship between the reinforcing potential of CNCs and their physical characteristics, such as their morphology, dimensions, and aspect ratio.

• 한국수소및신에너지학회논문집
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• 제15권4호
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• pp.333-340
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• 2004

In this study, thermochemical degradation by pyrolysis-liquefaction of cellulose, the effects of reaction time, reaction temperature, conversion yield, degradation properties and degradation products were investigated . Experiments were performed in a tube reactor by varying reaction time from 20 to 80 min at $200{\sim}500^\circ{C}$. Combustion heating value of liquid products from thermochemical conversion processes of cellulose was in the range of 6,920~6,960cal/g. After 40min of reaction at $400^\circ{C}$ in pyrolysis-liquefaction of cellulose, the energy yield and mass yield was as high as 54.3% and 34.0g oil/100g raw material, respectively. The liquid products from pyrolysis-liquefaction of cellulose contained various kinds of ketones, phenols and furans. ketones and furans could be used as high-octane-value fuels and fuel additives. However, phenols are not valuable as fuels.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.89-94
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• 2001

The binding of cellobiohydrolases to cullulose is a crucial initial step in cellulose hydrolysis. In the search for a detailed understanding of the function of cellobiohydrolases, much information concerning how the enzymes and their constituent catalytic and cellulose-binding changes during hydrolysis is still needed. The adsorption of purified two cellobiohydrolases (Ce17A and Ce16A) from Trichoderma reesei cellulase to microcrystalline cellulose has been studied. Cellobiohydrolase II (Ce16A) does not affect the adsorption of cellobiohydrolase I (Ce17A) significantly, and there are specific binding sites for both Ce17A and Ce16A. The adsorption affinity and tightness of the cullulase binding domain (CBD) for Ce17A are larger than those of the CBD for Ce16A. The CBD for Ce17A binds more rapidly and tightly to Avicel than the CBD for Ce16A. The decrease in adsorption observed when the two cellobihydrolases are studied together would appear to be the result of competition for binding sites on the cellulose. Ce17A competes more efficiently for binding sites than Ce16A. Competition for binding sites is the dominating factor when the two enzymes are acting together, furthermore adsorption to sites specific for Ce17A and Ce16A, also contributes to the total adsorption.

• 한국염색가공학회지
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• 제5권3호
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• pp.173-181
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• 1993

Dyeing cotton fabric with direct dye (C. I. Direct Blue 15) by redox sytem of ammonium persulfate as an oxidant and glucose as reductant was studied. It was found that covalent bond between dye and cellulose molecule can be formed by free radical produced by the redox system in the dye bath, which enhanced significantly the color strength. The retained color strength after DMF extraction was much better in the presence than in the absence of the redox sytem. The optimum dyeing condition was 0.028 mol/$\ell$(APS/Glucose each) of redox concentration, 65$^{\circle}C$ of dyeing temperature and 60min of dyeing time. The color variation on the dyed sample had not been observed as a result of fixed ${\lambda}_max$.

• Journal of Pharmaceutical Investigation
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• 제21권4호
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• pp.253-262
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• 1991

Microencapsulation of sodium ascorbate with cellulose acetate phthalate(CAP) by coacervation/ phase separation method were carried out. Various factors affecting microencapsulation, i.e., surfactant concentration. CAP concentration, stirring speed and treatment of spermaceti as a sealing agent were studied. Dissolution rate. particle size distribution, surface feature and stability test were investigated. CAP microcapsules prepared using 0.5% span 80 as a surfactant showed smooth and round surfaces. The release of sodium ascorbate was retarded by microencapsulation with CAP and by sealant treatment with spermaceti. When triturated with sodium bicarbonate, CAP microcapsules were more stable than unencapsulated sodium ascorbate under various RH conditions at $37^{\circ}C$.