• Journal of Conservation Science
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• v.37 no.6
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• pp.648-658
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• 2021

In this study, we aimed to analyze the chemical changes that occur in Korean paper in an accelerated deterioration environment of 105℃. We selected the Korean paper produced with different types of cooking agents (plant lye, Na₂CO₃) and during different manufacturing seasons (winter, summer). The degree of deterioration of the Korean paper was confirmed by measuring the brightness, yellowness, and pH level, and the degree of change in each vibrational region of cellulose as deterioration progressed through infrared (FT-IR) spectroscopy. The FT-IR analysis showed that, as deterioration progressed, the absorbance of the amorphous region in cellulose decreased, whereas the absorbance of the crystalline region slightly increased. X-Ray diffraction (XRD) analysis and Raman spectroscopy were performed to verify the changes in the crystalline and amorphous regions in cellulose indicated by the FT-IR results. Furthermore, the crystallinity index (CI) was calculated; it showed a slight increase after deterioration; therefore, CI was confirmed to follow the same trend as that observed for absorbance in the FT-IR results. In addition, as a result of Raman spectroscopic analysis, the degree of decomposition of the amorphous region in the cellulose under the manufacturing conditions was confirmed by the fluorescence measured after the deterioration.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2165-2172
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• 2017

Lignocellulose is now a promising raw material for biofuel production. However, the lignin complex and crystalline cellulose require pretreatment steps for breakdown of the crystalline structure of cellulose for the generation of fermentable sugars. Moreover, several fermentation inhibitors are generated with sugar compounds, majorly furfural. The mitigation of these inhibitors is required for the further fermentation steps to proceed. Amino acids were investigated on furfural-induced growth inhibition in E. coli producing isobutanol. Glycine and serine were the most effective compounds against furfural. In minimal media, glycine conferred tolerance against furfural. From the $IC_{50}$ value for inhibitors in the production media, only glycine could alleviate growth arrest for furfural, where 6 mM glycine addition led to a slight increase in growth rate and isobutanol production from 2.6 to 2.8 g/l under furfural stress. Overexpression of glycine pathway genes did not lead to alleviation. However, addition of glycine to engineered strains blocked the growth arrest and increased the isobutanol production about 2.3-fold.

• Polymer(Korea)
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• v.28 no.1
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• pp.92-102
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• 2004

(6-Cholesteryloxycarbonylpentoxypropyl)celluloses (CHPCs) with degree of esterification (DE) ranging from 2.25 to 2.91 were synthesized by reacting hydroxypropyl cellulose with 6-cholesteryloxycarbonylpentanoyl chloride. The acrylic esters of CHPCs (CHPCEs) and their photocrosslinked films with liquidcrystalline order were also synthesized. The thermotropic properties of mesophase for both uncrosslinked and crosslinked samples and the swelling behavior of the crosslinked samples in acetone were investigated. The hydroxypropyl cellulose exhibited an enantiotropic cholesteric phas, while all the uncrosslinked cholesterylbearing samples exhibited a monotropic cholesteric phases; the 6-cholesteryloxycarbonylpentanoyl chloride also showed a monotropic smectic phase. The hydroxypropyl cellulose formed a right-handed helix whose optical pitch (λ$\sub$m/) increases with temperature, whereas all the uncrosslinked derivatives farmed left-handed helices whose λ$\sub$m/'s decreased with temperature. The thermal stability of the mesophase and the magnitude of λ$\sub$m/ at the same temperature for both CHPCs and CHPCEs decreased with increasing DE. All the crosslinked samples, in constrast with CHPCEs, did not display reflection colors but exhibited an anisotropic swelling characteristic of crosslinked gel retaining liquid-crystalline order.

• Journal of the Korean Wood Science and Technology
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• v.49 no.4
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• pp.287-298
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• 2021

Torch ginger (Etlingera elatior Jack) is a potential source of lignocellulose material for various derivative products. This study aims to determine the chemical components, ratio of syringyl to guaiacyl units (S/G) in lignin, and crystallinity of the biomass of torch ginger. The effects of soda pulping on the chemical characteristics of torch ginger pulp were also studied. Pulping of the chips was conducted with active alkali of 15%, 20%, and 25% and a Liquor-to-Wood (L/W) ratio of 4:1, 5:1, and 6:1. The impregnation and pulping times at maximum temperature (170℃) were 120 and 90 min, respectively. To assess the effect of treatments on the properties of pulping, a two-factorial experimental design was applied. Results showed that the content of α-cellulose and hemicellulose in the torch ginger was 48.48% and 31.50%, respectively, with an S/G ratio of 0.70 in lignin. Soda pulping changed the crystalline structure of the biomass from triclinic to monoclinic. Active alkali, L/W ratio, and interactions considerably influenced the observed responses. The degree of delignification increased with an increase in the loading of active alkali, which lead to a decrease in the kappa number of the pulp. An active alkali content of 25% and an L/W ratio of 6:1 resulted in the highest delignification selectivity with a kappa number of 2.78 and a yield of 24%. Given its cellulose content and ease of pulping, torch ginger can be a potential raw material for derivative products that require delignification as pretreatment. However, the increase in cellulose crystallinity should be considered when converting torch ginger to bioethanol.

• Clean Technology
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• v.16 no.1
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• pp.19-25
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• 2010

In this work, the conversion of crystalline cellulose into polyols in the presence of hydrogen was examined over noble metal (Pt, Ru, Ir, Rh, and Pd) catalysts supported on activated carbon. For comparison, Pt/${\gamma}-Al_2O_3$ and Pt/H-mordenite were also investigated. Several techniques: $N_2$ physisorption, X-ray diffraction(XRD), inductively-coupled plasma-atomic emission spectroscopy (ICP-AES), temperature-programmed reduction with $H_2$ ($H_2$-TPR) and CO chemisorption were employed to characterize the catalysts. The cellulose conversion was not strongly dependent on the types of the catalyst used. Pt/AC showed the highest yields to polyols among activated carbon-supported noble metal catalysts, viz. Pt/AC, Ru/AC, Ir/AC, Rh/AC and Pd/AC.

• Journal of the Korean Wood Science and Technology
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• v.29 no.1
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• pp.60-67
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• 2001

The microscopic characteristics and cellulose structures of primary and secondary tissues in Pinus densiflora S. et Z. were examined. Cells of primary tissue in cross section showed an irregular arrangement and round shape. Fiber lengths were 200 to $250{\mu}m$ in primary tissue, and 1,500 to $1,600{\mu}m$ in secondary tissue. Cell diameters in primary tissue were larger than those in secondary tissue; 40 to $50{\mu}m$ in former and 10 to $20{\mu}m$ in latter. Crystallite width and d-spacing of (200) in both tissues did not show any significant differences. However, crystallinity indices by Segal's method showed significant differences as 23% in primary tissue and 35% in secondary tissue. In the orientation of cellulose microfibril, primary tissues had a random pattern, whereas, secondary tissues presented an oriented pattern with 20 to 30 degree. The cellulose crystalline of primary tissue was easily transformed into cellulose II by mercerization, but that of secondary tissue hardly transformed. It is considered that the difference of crystal transformation in both tissues could be caused by the difference of lignification.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.629-632
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• 2001

The strain FJ1 isolated from a rotten wood showed high activity to hydrolysis of cellulosic materials. The strain produced largely enzymes related in hydrolysis of cellulose and hemicellulose, such as CMCase, xylanase, ${\beta}-glucosidase$ , and avicelase. The culture conditions(pH, temperature, inoculation concentration) and substrate specificity to various cellulosic materials were examined to elevate productivity of the enzymes. The enzyme activities of CMCase and xylanase were 13.5U/ml and 24.3U/ml in agitation culture using Mandel's medium, respectively. The high activity of the enzymes was earned when mixed cellulosic materials of rice straw, sawdust, and pulp as substrates, indicating that the strain FJ1 could use crystalline substrates.

• Journal of Microbiology
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• v.33 no.2
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• pp.109-114
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• 1995

Alkalophilic Cephalosporium sp. RYM-202 produced multiple xylanases extracellularly. One of these xylanases was purified to electrophoretical homogeneity by chromatography with DEAE-Sephadex A-50, Sephacryl S-200 HR and Superose 12 HR. The purified xylanase differed from most other microbial xylanases in that it had low-molecular weight and acidic isoelectric point. The molecular weight of the xylanase in that it had low-molecular weight and acidic isoelectric point. The molecular weight of the xylanase was 23 kDa by SDS-polyacrylamide electrophoresis and 24 kDa by gel permeation chromatography, and the isoelectric point was 4.3. The xylanase had the highest activity permentation chromatography, and the isoelectric point was 4.3. The xylanase had the highest activity permeation chromatography, and the isoelectric point was 4.3. The xylanase had the highest activity at pH 8.0 and 50 .deg.C. It was stable over a wide range of pH and retained more than 80% of its original activity after 24 h of incubation even at pH 12. The Km values of this enzyme on birchwood xylan and oat spelts xylan were 2.33 and 3.45 mg/ml, respectively. The complete inhibition of the enzyme of n-bromosuccinimide suggests the involvement of tryptophan in the active site. The sylanase lacked activity towards crystalline cellulose and carboxymethyl cellulose.

• Textile Coloration and Finishing
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• v.15 no.4
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• pp.73-79
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• 2003

It is generally known that cotton treated with liquid ammonia has better soft handle, wrinkle recoveries and stability of appearance as compared with the alkali mercerized cotton. In this study, the various cotton fabrics treated with liquid ammonia$(NH_3)$, sodium hydroxide(NaOH) and sodium hydroxide(NaOH)/liquid ammonia$(NH_3)$ and untreated cotton fabric were investigated and compared in terms of physical properties and dyeing behavior. As the result, the strength of four kinds of cotton fabrics were similar. But the elongation of cotton treated with liquid ammonia increased slightly. Liquid ammonia treatment reduced the crystallinity of cotton and the crystalline structure of cotton transformed from cellulose 1 to mixed structure of celluloseIand III. In dyeing, dyeing rate decreased but equilibrium dye uptake increased by liquid ammonia treatment of cotton fabrics.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.25-33
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• 1985

The cell-free cellulolytic enzyme was separated into 3 different enzyme proteins by gel-filtration and ion-exchange chromatography. These fractions were named enzyme A, enzyme B and enzyme C. The mode of action of each of the separated enzymes on crystalline cellulose was examined using infrared spectroscopy and X-ray crystallography. It was concluded that enzyme B is of the $C_1-type$ and reduces the crystallinity of the subatrate by generation an unstable glucopyranose ring structure, whilst enzymes A and C are of the $C_x-type$ and hydrolyse the reaction product of enzyme B to constituent sugars. A reaction scheme for this cellulase system is proposed and discussed.