• 한국의류학회지
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• 제28권7호
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• pp.873-881
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• 2004

This research was aimed to investigate the effect of enzyme and the addition of chelators on rotting of the Kenaf bast. Enzyme rotting was effective only when the chelators were added with the enzyme. EDTA was a more effective chelator than oxalic acid under 1% concentration. There was no difference in the rotting effect under different enzyme concentration levels, and under different treatment time and temperature. Therefore, it was found that enzyme rotting can be carried out with low enzyme concentration(0.125%) at room temperature. Retting time can be shortened when higher enzyme concentration and higher temperature are applied. Cellulose I structure of kenaf fiber did not change after enzyme rotting, and different enzyme concentration did not affect the crytallinity structure. Non-cellulosic matters such as hemicellulose, lignin, and pectin were present in the descending order in the enzyme rotted kenaf fiber, and there were no differences in their amounts due to enzyme concentration levels. There was no difference in the dyeabilities of kenaf fiber rotted with different enzyme concentration levels. Enzyme rotted kenaf fiber showed better cyeability when pectin, lignin, and hemicellulose were removed.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.150-155
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• 2001

It has been observed that water, which is absolutely essential for enzyme activity, can induce the agglomeration of enzyme particles in organic media. Although enzyme agglomeration is significant in that it usually reduces enzyme activity and stability, little attention has been paid to the quantitative analysis of enzyme agglomeration behavior in nonaqueous biocatalytic systems. In this study, the effect of water and silica gel on enzyme agglomeration were investigated using Candida rugosa lipase and cyclohexane as a model enzyme and an organic medium. The extent of enzyme agglomeration was quantified by sieve analysis of freeze-dried agglomerates. Increasing the water content of the medium increased the size of the enzyme agglomerates, and it was found that water produced during the esterification reaction could also promote the agglomeration of enzyme particles suspended in organic media. On the other hand, the size of the enzyme agglomerates was remarkably reduced in the presence of silica gel at the same water content. We also show that this increase in the size of enzyme agglomerates results in lower reaction rates in organic solvents.

• Journal of Plant Biotechnology
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• 제6권1호
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• pp.63-67
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• 2004

A simple procedure for the extraction of the lipolytic enzyme from rice bran has been developed. High activity of lipolytic enzyme was obtained by first defatting the rice bran to remove lipid components with various extraction conditions. Then, after rove cycles of aqueous extraction, rice bran lipolytic enzyme was purified using micro- and ultrafiltration apparatus. Lipolytic enzyme activity was estimated by its hydrolytic action of tributyrin. The result indicated that the standard activity curve of butyric acid showed that the potential rice bran enzyme is a hydrolytic lipase enzyme. In addition, it showed higher lipolytic activity and specific enzyme activity with further purification by micro- and ultrafiltration. The size of rice bran lipase enzyme was identified through 15 ％ SDS-PAGE. The molecular weight of the rice bran lipase enzyme was 41 kDa.

• 한국미생물·생명공학회지
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• 제6권1호
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• pp.33-40
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• 1978

Immobilization of alkaline protease was investigated by absorbing the enzyme on adsorbents. Alkaline protease was adsorbed on silica gel selected as a carrier to immobilize the enzyme. In this study, properties of the immobilized enzyme were compared with those of the soluble enzyme. 1) The optimum pH (10.0) of the enzyme was not changed, but the activity was increased at alkaline pH by immobilization. 2) The optimum temperature of the immobilized enzyme was shifted from 50$^{\circ}C$ to 45$^{\circ}C$, while the temperature-activity Profile became broader than those of the soluble enzyme. 3) The pH stability of the immobilized enzyme was significantely increased at pH 4.0, althouth it did not change in the neutral and alkaline pH region. 4) The heat stability of the enzyme was enhanced in the temperature range of 55$^{\circ}C$∼65$^{\circ}C$ by the immobilization. 5) The immobilized enzyme retained 40％ of its original activity after repetitive use for 6 times. 6) The enzyme stability was greately improved for a prolonged storage at 4$^{\circ}C$.

• 한국잠사곤충학회지
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• 제42권2호
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• pp.104-108
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• 2000

To hydrolyze insolule sericin the enzyme hydrolysis was used, and then obtained the results as given belows. When insoluble sericin was hydrolyzed by enzyme treatment, the solubility was best at pH 7, 60$\^{C}$ and was slightly increased both above 2 hours treatment and above 10% of enzyme concentration. As the results of electrophoresis, the distribution of molecular weight of sericin powder obtained by enzyme hydrolysis was very weak and showed in the wide range having no distinguishable band. Average degree of polymerzations (A.D.P.) of sericin hydrolyzed by enzyme were about 4.1∼6.3, average molecular weight were about 470∼730. The whiteness of the sericin powder obtained by enzyme hydrolysis was high and increased slightly with higher treatment concentration of enzyme. As the results of amino acid analysis, the amino acid analysis, the amino acid composition of the sericin powder from the enzyme treatment were similar to which located at near 230$\^{C}$ and 320$\^{C}$. The peak of near 230$\^{C}$ could not been found in the sericin powder obtained by enzyme hydrolysis.

• BMB Reports
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• 제37권4호
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• pp.394-401
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• 2004

The purpose of this paper is to suggest that the prominence of Haldane's explanation for enzyme catalysis significantly hinders investigations in understanding enzyme structure and function. This occurs despite the existence of much evidence that the Haldane model cannot embrace. Some of the evidence, in fact, disproves the model. A brief history of the explanation of enzyme catalysis is presented. The currently accepted view of enzyme catalysis -- the Haldane model -- is examined in terms of its strengths and weaknesses. An alternate model for general enzyme catalysis (the Shifting Specificity model) is reintroduced and an assessment of why it may be superior to the Haldane model is presented. Finally, it is proposed that a re-examination of many current aspects in enzyme structure and function (specifically, protein folding, x-ray and NMR structure analyses, enzyme stability curves, enzyme mimics, catalytic antibodies, and the loose packing of enzyme folded forms) in terms of the new model may offer crucial insights.

• 펄프종이기술
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• 제47권1호
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• pp.59-65
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• 2015

In this study, we evaluated optimum condition of enzyme with pH and temperature for preparation of microfibillated cellulose(MFC). Well-known endo-glucanase, three enzymes were used and CMC was used for substrate. Enzyme activity was evaluated using DNS method and absorbance with UV/VIS spectrophotometer. The enzyme shown the greatest activity was reacted with pulps at optimum condition for 1 hour and treated pulps beated until 100 mL CSF. Enzyme B and Enzyme L was the higher enzyme activity below 0.1% concentration and Enzyme N was the lowest enzyme activity. At various pH and temperature conditions, enzyme activity of Enzyme B was higher than the others at the same concentration. Especially enzyme activity at $50^{\circ}C$ of Enzyme B was almost not changed over pH 6.0. Optimum condition of three enzyme was pH 6 or pH 7 and $50^{\circ}C$ or $60^{\circ}C$. Also beating efficiency of enzyme treated pulps with Enzyme B is 55.6%.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.389-393
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• 2003

Present study investigate the effect of enzyme supplementation, methods (applied to rumen or enzyme treated diet) compared with no enzyme diet, on rumen fermentation and apparent nutrient digestibility in a $3{\times}3$ Latin square design with three rumen cannulated Korean Native goats. In situ rumen degradation kinetics was studied in three rumen cannulated Holstein steers. Three diets were, no enzyme, 1% enzyme in rumen and 1% enzyme in diet. The enzyme was sprayed onto forage, and the forage: concentrate ratio was 30:70. Degradation kinetics was studied with three enzyme levels (0, 1 and 2%, w/w) and four pre-treatment times (0, 1, 12 and 24 h). Results suggested that enzyme application method did not affect rumen fermentation, ruminal enzyme activity and total tract apparent digestibility. Nutrient degradation rate and effective degradability of DM, NDF and ADF increased with increasing enzyme level and pre-treatment times. Degradation of nutrients was affected by enzymes levels or pre-treatment times. Therefore, it is probable that the improved degradation may be due to the supplemented exogenous hydrolytic enzymes under a certain condition.

• Journal of Animal Science and Technology
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• 제45권1호
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• pp.131-142
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• 2003

본 연구는 유우의 생산성 향상을 위하여 유우 사료에 fibrolytic enzyme을 첨가하여 반추위내 발효 성상과 비유중인 젖소의 생산성에 미치는 영향을 평가하였다. 본 실험의 결과를 요약하면 다음과 같다. In vitro 실험을 통하여 NDF 함량 수준이 다른 TMR 사료에 fibrolytic enzyme을 3가지 수준(0, 0.05, 0.1%)으로 달리하여 첨가하였을 때 나타난 NDF 소화율은 효소 첨가시 다소 증가하는 경향을 보였으며 NDF 수준별로는 NDF 38 및 43% 수준보다 NDF 34% 수준에서 NDF 소화율이 낮은 경향을 나타내었는데 이는 본 시험 사료의 조성 성분으로 보아 NDF 성분 구성상 hemicellulose 함량이 높아 이 점이 반추위내 NDF 소화율에 영향을 주었다고 사료된다. 반추위액의 pH는 fibrolytic enzyme의 첨가 수준에 의한 영향보다는 NDF 수준에 의해 영향을 더 받은 것으로 나타났으며(P<0.001) NH3-N 생성도 전체적으로 fibrolytic enzyme 첨가에 따른 효과가 나타나지 않았다. Acetic acid의 생성량은 NDF 수준에 의해 유의한 영향을 받았으나 (P<0.05) propionic acid의 생성량은 처리구간에 큰 차이를 나타내지 않았다. Acetic acid와 propionic acid 생성량 모두 효소 첨가에 의한 영향은 유의하게 나타나지 않았고 A/P ratio는 NDF 34% 수준의 fibrolytic enzyme 첨가구에서 무첨가구에 비해 다소 높은 경향을 나타내었다. CMCase의 효소 활성은 NDF 34 및 43% 수준에서 fibrolytic enzyme 첨가구(0.05, 0.1%)가 무첨가구에 비해 높은 효소 활성을 보였다. Xylanase의 효소 활성은 배양 개시 후 0시간대부터 12시간대까지는 효소 활성이 완만히 감소하였고 24시간 이후부터는 급격히 감소하였다. In vivo 실험을 이용하여 fibrolytic enzyme 첨가에 따른 착유우의 생산성 변화 결과는 다음과 같다. Fibrolytic enzyme 첨가에 의한 산유량은 enzyme 첨가구와 무첨가구에서 각각 25.80 및 23.90kg/d로서 enzyme 첨가구에서 약 8% (1.90kg/d) 증가하는 결과를 나타내었다. 유지방 및 유단백 함량의 경우는 fibrolytic enzyme 첨가구와 무첨가구간 차이가 없었으나 일일 생산량으로 환산하여 평가하면 enzyme 첨가시 유성분 생산량이 유의하게 증가하는 결과를 보였다 (P<0.01). 이상의 결과들로 볼 때, in vitro 실험의 경우 fibrolytic enzyme 첨가시 반추위내 발효성상에 명확한 변화를 보여주지 못했지만 enzyme 첨가에 따라 전반적으로 NDF 소화율이 다소나마 증가하는 경향을 보였다. In vivo 실험 결과를 종합하면 착유우 사료에 fibrolytic enzyme을 첨가시 유성분의 변화보다 유량의 증가 효과가 나타났으며 이는, 사료섭취량을 제한한 본 실험의 특성상, 사료섭취량 증진 효과가 아니라 체내 영양소 이용성 증진에 따르는 효과라고 판단되었다. 반추동물의 생산성 향상을 위한 방안으로서 fibrolytic enzyme 이용 효과는 연구자에 따라 다양한 결과를 나타내므로 효소의 적용 방법에 대한 연구가 더 필요하다고 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1729-1735
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• 2004

A total of 140 weaning pigs were used to determine the effects of digestive enzyme supplementation to corn-soybean meal diets on growth performance, physiological changes of small intestine, microorganisms and pH in the gastrointestinal tract. Two kinds of enzyme complex (A, B) were used in this experiment. Pigs were allotted in a completely random design (CRD) to five replicates with four pigs per pen. Diets and water were provided for ad libitum consumption. Treatments included 1) Control: without enzyme supplementation, 2) Enzyme A 0.05%, 3) Enzyme A 0.10%, 4) Enzyme A 0.15%, 5) Enzyme B 0.05%, 6) Enzyme B 0.10%, 7) Enzyme B 0.15% in the diets. A total of 24 crossbred barrows 25.78${\pm}$0.55 kg BW fitted with simple ileal T-cannulas were used to evaluate the effect the enzyme addition on the nutrient digstibility. Pigs were allotted 4 treatments (No enzyme, enzyme A 0.05%, enzyme A 0.1%, enzyme A 0.15%), 6 replicates according to a completely random design (CRD). Another digestibility trial was followed for enzyme complex B. Twenty pigs, average 31.92${\pm}$0.37 kg BW, fitted with simple ileal T-cannulas for digestibility trial. Neither enzyme A nor enzyme B affected on fecal or ileal digestibility of dry matter, gross energy, crude protein, crude fat and crude ash (p>0.05). The apparent fecal digestibilities of all the nutrients were higher in total feces collection method than in indirect method. At the end of feeding trial, 21 pigs were slaughtered for examining the morphological changes of small intestine and the concentration of microorganisms in the ileum and the colon. Growth performance, intestinal morphology and pH of ileum and colon were not affected by the either enzyme complex supplementation (p>0.05). These results suggested that enzyme complex A and enzyme complex B were of no benefit to early-weaned pigs when corn-soybean meal based diet was provided.