• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.20-27
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• 2001

An effective method for production of glucose was developed using enzymatic hydrolysis of Suwon poplar by the cellulase. Enzymatic hydrolysis of wood is the reaction to produce glucose from wood using enzyme which derives from microorganism. Glucose can be transferred easily to ethanol by fermentation. Ethanol is the starting material for producing acetone, butanol, citric acid and lactic acid. The mechanism of the enzymatic hydrolysis of cellulose are reasonably explained in terms of the sequential action of three different types of enzymes, endo-cellulase, ex-cellulase, and $\beta$ -glucosidase. The goal of this work was to investigate the cellulose hydrolysis pretreated polar with various concentration NaOH, the crystallinity of cellulose, lignin contents and the degree of hydrolysis.

• Journal of the Korean Wood Science and Technology
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• v.20 no.1
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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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• v.4 no.3
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• pp.235-240
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• 1989

A novel pretreatment of rice straw has been developed to increase the reactivity of cellulose, in particular to increase the rate and extent of cellulose enzymatic hydrolysis. This technique is called ammonia-freeze-explosion method and relies on treatment of the lignocellulosic material with a volatile liquid under pressure followed by pressure release to evaporate the liquid and reduce the temperature by Bme E. Dale of Texas A & M University. Volatile liquids which also chemically explosion and swell lignocellulosic materials are particularly effective when used in this technique. Above four times of conversion of cellulose to glucose has been achived by enzymatic hydrolysis of rice straw with this method.

• Korean Journal of Pharmacognosy
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• v.7 no.2
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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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• v.22 no.7
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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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• v.13 no.6
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• pp.687-692
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• 1998

Experimental studies were carried out on the use of supercritical fluid in enzymatic hydrolysis of cellulose. In order to effectively perform the hydrolysis the enzyme has to maintain stability and activity in the supercritical carbon dioxide solvent. In the experiment it was found that the stability of cellulase was maintained up to 160 atm for 90 min at $50^{\circ}C$. In the enzymatic hydrolysis of cellulose at supercritical conditions using carbon dioxide at 80 atm and $50^{\circ}C$ for 90 min, the results showed that glucose yield was 100%, which was 1.5 times as compared to that in atmospheric condition when the substrate (Avicel) concentration was 20 g/L. For the substrate concentration of 60 g/L, the glucose yield was increased by 1.2 times as compared to that in atmospheric condition.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.5
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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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• v.33 no.2
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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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• v.15 no.1
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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.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.41-46
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• 1980

Low molecular weight endo-glucanase was partially purified from cellulase complex using Sephadex G-100 gel chromatography. Biochemical properties of the purified component was investigated. Optimum pH and temperature determined were 6.0 and 5$0^{\circ}C$, respectively. Enzymatic hydrolysis of four cellulosic substrates having varying crystallinity was evaluated. It was found that hydrolysis of amorphous region was followed by the hydrolysis of crystalline region. In order to examine the effect of adsorption of the enzyme onto the cellulosic substrates on the hydrolysis kinetics, adsorption studies were carried out. Time course of adsorption of low molecular weight endo-glucanase onto various cellulostances was observed for 25 min. The rate and amount of adsorption to amorphous cellulose was greater than those to the crystalline cellulose. This result suggested that the role of endo-glucanasc was more important to the hydrolysis of amorphous cellulose than to the crystalline region of the cellulose.