• The Korean Journal of Ecology
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• v.25 no.6
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• pp.399-403
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• 2002

Cellulose mass loss by cellulose filter papers was measured for 3 time (35 days, 70 days, 105 days) incubation during the growing season (from May to September 2002) with different tree density and after fertilization in a Japanese larch (Larix leptolepis) plantation. Cellulose mass loss rates were significantly different between tree density types and fertilization treatments during the study periods. After 105 day incubation of cellulose filter paper, cellulose mass loss rates were significantly higher in the low tree density (70.1 $\%$) than in the high tree density (49.9$\%$). Cellulose mass loss rates averaged 62.8$\%$ in the fertilization and 58.9% in the unfertilization treatments during the same periods. However, cellulose mass loss was not significantly different between the forest floor and the mineral soil layer except for 35 day incubation. The results indicate that cellulose decomposition rates are a useful index to express differences in organic matter decomposition activity in different tree density and after fertilizer treatments.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.508-514
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• 2010

Regenerated cellulose fibers were prepared from three pulps containing different degree of polymerization(DP) and $\alpha$-cellulose contents by dry-jet wet spinning technique with cellulose dope in N-methylmorpholin N-oxide (NMMO). The effect of antioxidant, n-propyl gallate (PG) on the properties of different regenerated celluloses was studied using X-ray diffraction, copper number calculation, and viscometry. The degradaqtion of regenerated cellulose from pulp containing higher DP and lower $\alpha$-cellulose content was occurred more seriously. The tensile strength and initial modulus of regenerated cellulose fiber obtained from NMMO dope with PG were higher than those of fiber obtained from NMMO dope without PG. All fibers showed the round shape cross section and typical cellulose II crystalline structure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.181-184
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• 2003

We investigated the effect of ethanol on the production of cellulose and acetic acid fermentation by Gluconacetobacter persimmonensis KJ145. Results showed that bacterial cellulose productivity was highest when 2% ethyl alcohol was added to apple-juice medium. For acetic acid production, 7% ethyl alcohol was needed. Optimal concentration of ethyl alcohol was 5% for simultaneous production of bacterial cellulose and acetic acid. For simultaneous production of bacterial cellulose and acetic acid, optimal nitrogen source and optimal concentration were corn steep liquor and 15% (w/v), respectively Optimal culture time for simultaneous production of bacterial cellulose and acetic acid was 14 days. At the optimal condition, Cluconacetobacter persimmonenis KJ145 produced 7.55 g/L of bacterial cellulose (dry weight).

• KSBB Journal
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• v.8 no.3
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• pp.230-236
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• 1993

A Chitulose film was made by dissolving chitin and cellulose in a dimethylacetamide/LiCl solvent system This film was completely degraded in 20 days in soil and penetrated by soil microorganisms in 16-26 hours. A permeability analysis of the film showed that water permeability was in the range of 0-187.5 $1/m^2$/day, depending upon the ratio of chitin to cellulose and decreased with increasing a cellulose content in the Chitulose film The permeabilities of organic compounds, $Na^+$ and oxygen change with the composition of the Chitulose file The film was tested with a burned 2~3degree rat for exploring its use as artificial skin. The rat was completely cured within 31 days without inflammation.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.300-305
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• 1997

Effect of a nonionic surfactant, Tween 20 on the adsorption and kinetic mechanism for the hydrolysis of a microcrystalline cellulose, Avicel PH 101, by endoglucanase Ⅰ (Endo Ⅰ) and exoglucanase Ⅱ (Exo Ⅱ) isolated from Trichoderma viride were studied. The Langmuir isotherm parameters, amount of maximum adsorption (Amax) and adsorption equilibrium constant (Kad) for the adsorption, were obtained in the presence and the absence of nonionic surfactant. On the addition of Tween 20, the Kad and Amax values of Exo Ⅱ were decreased, while those of Endo Ⅰ were not affected. These indicate that the adsorption affinity of Exo Ⅱ on the cellulose is weakened by nonionic surfactant, and the surfactant enhanced desorption of Exo Ⅱ from insoluble substrate. The enzymatic hydrolysis of the cellulose can be described by two parallel pseudo-first order reactions using the percentages of easily (Ca) and hardly (Cb) hydrolyzable cellulose in Avicel PH 101 and associated rate constants (ka and kb). The Ca value was increased by adding Tween 20 for all enzyme samples (Exo Ⅱ, Endo Ⅰ and their 1:1 mixture) implying that the low-ordered crystalline fraction in the cellulose may be partly dispersed by surfactant. The ka value was not affect by adding Tween 20 for all enzyme samples (Exo Ⅱ, Endo Ⅰ and their 1:1 mixture). The kb value of Exo Ⅱ was increased by adding Tween 20, while that of Endo Ⅰ was not affected. This suggests that the surfactant helps the Exo Ⅱ desorb from microcrystalline cellulose, and increase the hydrolysis rate. These results were show that the increase of hydrolysis of cellulose by the nonionic surfactant is due to both the activation of Exo Ⅱ and partial defibrillation of the cellulose.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.5
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• pp.440-453
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• 2005

Objectives : To develop a bioactive membrane for guided bone regeneration (GBR), the biocompatibility and bone regenerating capacity of the cellulose membrane obtained from the Ascidians squirt skin were evaluated. Materials and methods : After processing the pure cellulose membrane from the squirt skin, the morphological study, amino acid analysis and the immunoreactivity of the cellulose membrane were tested. Total eighteen male Spraque-Dawley rats (12 weeks, weighing 250 to 300g) were divided into two control (n=8) and another two experimental groups (n=10). In the first experimental group (n=5), the cellulose membrane was applicated to the 8.0 mm sized calvarial bone defect and the same sized defect was left without cellulose membrane in the first control group (n=4). In the another experimental group (n=5), the cellulose membrane was applicated to the same sized calvarial bone defect after femoral bone graft and the same sized defect with bone graft was left without cellulose membrane in the another control group (n=4). Each group was sacrificed after 6 weeks, the histological study with H&E and Masson trichrome stain was done, and immunohistochemical stainings of angiogenin and VEGF were also carried out. Results : The squirt skin cellulose showed the bio-inductive effect on the bone and mesenchymal tissues in the periosteum of rat calvarial bone. This phenomenon was found only in the inner surface of the cellulose membrane after 6 weeks contrast to the outer surface. Bone defect covered with the bioactive cellulose membrane showed significantly greater bone formation compared with control groups. Mesenchymal cells beneath the inner surface of the bioactive cellulose membrane were positive to the angiogenin and VEGF antibodies. Conclusion : We suppose that there still remains extremely little amount of peptide fragment derived from the basement membrane matrix proteins of squirt skin, which is a kind of anchoring protein composed of glycocalyx. This composition could prevent the adverse immunological hypersensitivity and also induce bioactive properties of cellulose membrane. These properties induced the effective angiogenesis with rapid osteogenesis beneath the inner surface of cellulose membrane, and so the possibilities of clinical application in dental field as a GBR material will be able to be suggested.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.142-147
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• 1994

Characteristics of TNP-cellulose which prepared from carboxymethyl cellulose powder, CM32, as substrate for cellulase activity assay were investigated. Enzymatic hydrolysis of TNP-cellulose occured on the cellulose moiety but not on amide bonds, following Michaelis-Menten kinetics. Three cellulase preparations from Trichoderma viride, Aspergillus niger, and Cellulomonas sp. were tested for their pH and temperature dependences and compared with the method determining the increase in reducing power. The enzyme activity was found to have the same temperature range in both methods, however the pH range was broadened in the case of using TNP-cellulose as substrate. The colorimetric method for cellulase assay using TNP-cellulose as substrate was compared with the other methods: one based on determination of the increase in reducing power; and the other based on determining the decrease in viscosity of Na-CM-cellulose solution. The activities measured by the colorimetric method showed a linear correlation with the enzyme concentration of certain range in all three enzymes tested, and the activity values were proportional to those obtained from the other methods. Depending on the enzyme, however, the activity values from this method were not always in proportion to those from the viscometric method. suggesting that this method was not specific for determination of the endo-type cellulase.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.3
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• pp.59-68
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• 2013

The cotton contains various impurities such as protein, wax, pectins, coloring matter, even though cotton has been a major source of pure cellulose. The purification processes have been commonly applied to obtain the pure cellulose. However the excessive purification treatments could lead to the damage in the cellulose structure which could result in the degradation of cellulose and the limited application of cotton cellulose. In this study, the changes in cellulose structural properties such as crystallinity and DP(degree of polymerization) by the various conditions of the purification processes were investigated. The less toxic agents such as hydrogen peroxide and sodium silicate were applied for the purification treatment in this study. The increase in the process times, the temperature and the applied amount of chemical agents resulted in the more purified cellulose. The DP of cotton cellulose was increased at the first weak conditions by the reduction of small molecules such as pectin, wax, and so on. Especially the 2 % addition amount of $H_2O_2$ with $Na_2SiO_3$ resulted in the higher value in the DP and the brightness compared to the 1.5 % addition amount of $H_2O_2$. However, the 4 % addition amount of $H_2O_2$ with $Na_2SiO_3$ showed the decreased value because of excessive treatment. In case of the changes in the crystallinity (Gjk), the highest value of the crystallinity was obtained by the 2% addition amount of $H_2O_2$ on the cotton cellulose, which showed similar with the change in the DP.

• Polymer(Korea)
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• v.34 no.6
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• pp.522-526
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• 2010

Bacterial cellulose is produced by the bacterium Gluconacetobacter xylinus, which forms a nanofibrous pellicle in its culture medium. We studied properties of the bacterial cellulose such as crystallinity, viscosity, morphology, and mechanical properties according to the carbon source. Static cultures of Gluconacetobacter sp. V6 were performed in three kinds of media: standard Hestrin-Schramm medium, and modified medium with either glycerol or molasses as carbon sources. Cell growth and cellulose yield were increased in the glycerol and molasses media. The culture in the glycerol medium improved the physical properties of cellulose such as crystallinity, intrinsic viscosity, and breaking stress. However, the culture in the molasses medium decreased crystallinity, crystallite size, and intrinsic viscosity of cellulose. In summary, the cellulose yield was remarkably improved in the molasses medium, but with inferior structural properties.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.863-866
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• 2003

This study was conducted to examine the effects of dietary cellulose levels on growth, nitrogen utilization, the retention time of diets in the digestive tract, and caecal microflora of 2-month-old Single Comb White Leghorn male chickens fed 3 purified diets that contained 0, 3.5% and 10% cellulose in equal amount of nutrients for 7 days. Body weight gain and nitrogen utilization were significantly higher (p<0.05), while total microflora counts in the caecal contents and retention time of the diet in the digestive tract were significantly lower (p<0.05) in the group fed 3.5% dietary cellulose compared with the group fed 10% dietary cellulose. Body weight gain, nitrogen utilization and retention time of the diet in the digestive tract decreased significantly while the total microflora count in the caecal contents increased significantly in the group fed 10% dietary cellulose compared to the group fed 0% dietary cellulose (p<0.05). Chickens fed 10% dietary cellulose had significantly increased counts of uric acid-degradative bacteria such as Peptococcaceae and Eubacterium, including Peptostreptococcus (p<0.05). The results suggest that cellulose in purified diets is an effective ingredient and the effects on growth, nitrogen utilization, caecal microflora counts and diet retention time in the digestive tract are dependent on the inclusion rate. Positive or negative effects of dietary cellulose are displayed by growth, nitrogen utilization, caecal microflora counts and retention time of the diet in the digestive tract. Positive effects were displayed when the inclusion rate is 3.5% and negative effects were displayed when that is greater than 3.5% of the diet, and the phenomenon is without reference to the age of the chickens.