• 임산에너지
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• 제20권2호
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• pp.20-27
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• 2001

글루코스 생산을 위한 효과적인 방법을 개발하기 위해서 cellulase에 의한 현사시 나무의 효소가수분해를 실시하였다. 목재의 효소가수분해는 미생물이 생산한 효소를 사용하여 글루코스를 생산하는 반응이다. 이렇게 얻어진 글루코스는 발효에 의해 쉽게 에탄올로 변환시킬 수 있다. 에탄올은 아세톤이나 부탄올, 시트릭산 그리고 락틴산을 제조하는 원료물질이나 석유자원을 대체할 수 있는 대체에너지 자원이다. 셀룰로오스의 효소가수분해 기작은 endo-cellulase, exo-cellulase 그리고 β-D-glucosidase라는 세 개의 서로 다른 형태의 효소가 연속적인 반웅에 의해 일어난다고 설명되어지고 있다. 본 실험의 목적은 다양한 농도의 수산화나트륨으로 현사시나무를 전처리 하여 이러한 전처리가 셀룰로오스의 결정화도와 리그닌함량에 미치는 영향과 가수분해율과의 관계를 조사하였다.

• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.23-27
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• 1992

81.9% of the cellulose delignified by acetosolv process was hydrolyzed in HCl-$AlCl_3$ hydrolysis system when $AlCl_3$ was used as catalyst in breaking down of glycosidic bond of cellulose. It was well compared that the HCl hydrolysis system without $AlCl_3$ as catalyst showed only 60~61% of the hydrolyzed yield. Also monosaccharide yield including glucose clearly increased when $AlCl_3$ was use. When concentration of HCl and $AlCl_3$ was increased, the hydrolyzed monosaccharide was increased within certain range. The monosaccharid yield out of the hydrolyzed reached 55.4% at optimum conditions which were identified as 20% of Hel solution, 0.03 Mol of $AlCl_3$, $120^{\circ}C$ of reaction temperature and 7 hours of reaction time employed in this study.

• KSBB Journal
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• 제4권3호
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• pp.235-240
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• 1989

본 연구에서는 매년 700여만톤 생산되는 볏짚을 자원화 하기 위하여 암모니아-냉동-파열법 (AFEX)을 사용하였다. AFEX으로 전처리된 볏짚은 처리되지 않은 것보다 대랴 4배 이상의 가수분해율을 얻을 수 있었다. 또한 어떼한 전처리 방법보다도 처리하는 과정이 쉽고 당화율도 90%로 이상이며, 경제성이 높다.

• 생약학회지
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• 제7권2호
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• pp.85-93
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• 1976

Since cellulose is the only organic material that is annually replenishable in very large quantities, we must explore ways to utilize it as a source of energy, food and chemicals. For the utilization of this resource, it is first enzymatic hydrolyzed to glucose, then the glucose can be used as a food, converted single cell protein by microorganism, fermented to clean burning fuel and other chemicals. Cellulolytic enzyme, cellulase, consists of two or three major components, $C_1-cellulase$, $C_x-cellulase$ and ${\beta}-glucosidase$. $C_x-cellulase$ are fairly common but $C_1-cellulase$ are quite rare. Trichoderma viride is the best source of active cellulose, especially $C_1-enzyme$. Saccharification rate of cellulose in greatly influenced by the degree of crystallinity and extent of lignification. But by the pretreatment the substrate with cellulose swelling agent, delignifying reagent and physical treatment, the degree of saccharification is enhanced. Thus, glucose syrups of 2 to 10% concentration are realized from milled newspaper. The enzymatic hydrolysis of such energy rich material, such as cellulose, to glucose is technically feasible and practically achievable on a very large scale.

• Bulletin of the Korean Chemical Society
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• 제22권7호
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• pp.716-720
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• 2001

To test the metal ion effect, hydrolysis experiments for two cellobiohydrolases (CBHⅠ and CBH Ⅱ) from Trichoderma reesei have been carried out in the presence of 10 mM metal ions, such as Cu++, Mn++, Ca++, Hg++, Ba++, Pb++, and Cd++. The addition of Mn++, Ba++, and Ca++(10 mM) during the hydrolysis of Avicel PH 101 caused an increase in the total reducing sugar (TRS) for CBH Ⅰ by 142, 135, and 114 percent, respectively. Those for CBH Ⅱ increased by 177, 175, and 115 percent, respectively. The Mn++ was the most stimulatory metal ion, whereas Hg++ was the most inhibitory metal ion. The adsorption experiments were performed to investigate how the influence of Mn++ and Hg++ on the hydrolysis is related to the adsorption of cellobiohydrolases on cellulose. The increase in TRS during hydrolysis by adding Mn++ caused an increase in adsorption affinity (Kad) and tightness (ΔHa). While, the decrease of TRS during hydrolysis by adding Hg++ caused a decrease in the adsorption affinity (Kad) and tightness (ΔHa). These results indicate the changes in the tightness and affinity of adsorption by adding metal ions play a crucial role in the degradation of the microcrystalline cellulose.

• KSBB Journal
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• 제13권6호
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• pp.687-692
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• 1998

본 연구는 초임계 이산화탄소를 이용한 섬유소의 효소 가수분해에서 효소의 안정성 및 반응조건에 관한 연구를 수행하였다. 초임계 이산화탄소에서 cellulase의 안정성에 대한 실헝결과 압력에 대한 영향에서는 80 atm에서 160 atm까지 효소의 안정성이 유지되었으며 200 atm 에서는 약간 감소하였다. 반응시간의 경우에는 150분까지 효소의 활성이 그대로 유지되었으며, 온도는 상압에서의 최적온도인 $50^{\circ}C$ 까지는 효소의 활성이 유지되었으나 그 이상의 온도에서는 효소의 변성에 의하여 활성이 감소하였다, 초임계 이산화탄소에서 cellulose를 120 atm과 $50^{\circ}C$ 애서 90분간 cellulase로 가수분해 반응을 수행한 결과 20 g/L 의 Avicel이 완전히 가수분해되어 100% 수율의 glucose블 얻을 수 있었으며, 이는 상압에서 보다 glucose 수율이 1.5배 증가한 결과이다. 반면에 cellulose fiber인 경우는 상압에서 보마 1.9배 증가하였다. 통일 조건에서 Avicel의 농드를 60 g/L로 한 경우에는 glucose 수율이 상압에서 보다 1.2배 증가하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권5호
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• pp.291-293
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• 2003

Batch reactors were employed to investigate the kinetics of cellulose hydrolysis under extremely low acid (ELA) and high temperature condition. The sawdust was pretreated by Auto-hydrolysis prior to the batch reaction. The maximum yield of glucose obtained from the batch reactor experiment was about 70% for the pretreated sawdust, this occurred at 210 and 22$0^{\circ}C$. The maximum glucose yield from the untreated sawdust was much lower at these temperatures, about 55%. The maximum yields of glucose from the lignocellulosics were obtained between 15th and 20th minutes after which gradual decrease was observed.

• Journal of Forest and Environmental Science
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• 제33권2호
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• pp.154-159
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• 2017

Enzymatic treatment was conducted to hydrolyze pure cellulose nanofiber (PCNF), holocellulose nanofiber (HCNF), and lignocellulose nanofiber (LCNF) for 6, 24 and 72 hours and thus-obtained nanofibers (1, 3, 5, 10 wt%) were used to reinforce polyvinyl alcohol (PVA). Glucose production yield was increased by enzymatic hydrolysis. Tensile strength and elastic modulus of all PVA nanocomposite reinforced three nanofibers were improved by increasing enzymatic hydrolysis time of nanofibers and these values were higher in order of nanocomposite reinforced with PCNF>HCNF>LCNF. Furthermore, tensile properties of nanocomposite with PCNF were increased by nanofiber content. Thermal stability of PVA was improved by adding nanofibers and by increasing nanofiber content.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.40-47
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• 2005

Modeling and simulation for simultaneous saccharification and fermentation (SSF) process in bioconversion of paper mill sludge to lactic acid was carried out. The SSF process combined the enzymatic hydrolysis of paper mill sludge into glucose and the fermentation of glucose into lactic acid in one reactor. A mathematical modeling for cellulose hydrolysis was developed, based on the proposed mechanism of cellulase adsorption deactivation. Another model for simple lactic acid fermentation was also made. A whole mathematical model for SSF was developed by combining the above two models for cellulose hydrolysis and lactic acid fermentation. The characteristics of the SSF process were investigated using the mathematical model.

• 한국미생물·생명공학회지
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• 제8권1호
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• pp.41-46
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• 1980

저분자량의 효소인 셀루라아제가 Sephadex G-100 gel chromatography를 사용하여 정제되었다. 정제된 성분의 생화학적 성질들이 조사되었는데 최적 PH와 온도가 각각 6.0과 5$0^{\circ}C$이었다. 서로 다른 결정도(crystallinity)를 갖고 있는 4가지 섬유소 기질의, 효소에 의한 가수분해가 측정되었다. 무정형(amorphous) 부분의 가수분해가 일어난 후에 결정화되어 있는 부분의 가수분해가 뒤따라온다는 것을 알 수 있었다. 효소가 섬유소 기질에 흡착되는 정도가 가수분해 반응에 미치는 영향을 보기 위해 흡착에 대한 연구가 수행되었다. 시간에 따라서 소분자량의 endo-glucanase가 여러가지섬유소 기질에 흡착되는 정도의 변화가 25분간 측정되었다. 무정형의 섬유소에 흡착되는 속도와 정도가 결정형 섬유소에 대한 그것들 보다 더욱 크게 나타났다. 이러한 결과는 endo-glucanase가 섬유소의 결정화 부분의 가수분해보다는 무정형부분의 가수분해에 대해서 더욱 중요한 역할을 한다는 것을 시사해 준다.