• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1366-1372
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• 2021

Bacterial nanocellulose (BNC) is a biocompatible material with a lot of potential. To make BNC commercially feasible, improvements in its production and surface qualities must be made. Here, we investigated the in situ fermentation and generation of BNC by addition of different cellulosic substrates such as Avicel and carboxymethylcellulose (CMC) and using Komagataeibacter sp. SFCB22-18. The addition of cellulosic substrates improved BNC production by a maximum of about 5 times and slightly modified its structural properties. The morphological and structural properties of BNC were investigated by using Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy and X-ray diffraction. Furthermore, a type-A cellulose-binding protein derived from Clostridium thermocellum, CtCBD3, was used in a novel biological analytic approach to measure the surface crystallinity of the BNC. Because Avicel and CMC may adhere to microfibrils during BNC synthesis or crystallization, cellulose-binding protein could be a useful tool for identifying the crystalline properties of BNC with high sensitivity.

• Microbiology and Biotechnology Letters
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• v.12 no.4
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• pp.305-309
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• 1984

A selective medium which allows growth of only cellulolytic bacteria was developed. The medium composed of 0.5% carboxymethylcellulose (CMC), 0.005% yeast extract, minerals and agar. Colony formation on this medium indicates overall activities of cellulose utilization. A subsequent test with Congo Red dye could distinguish extracellular cellulolysis from intracellular type.

• Journal of Microbiology and Biotechnology
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• v.4 no.2
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• pp.102-107
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• 1994

The $\beta$-1,4-endoglucanase gene from Actinomyces sp. 40 was cloned into Escherichia coli DH5$\alpha$ with pUC19. Chromosomal DNA from Actinomyces sp. 40 was cleaved with the restriction enzyme Sau3AI and ligated into pUC19 for the transformation of Escherichia coli DH5$\alpha$. Positive clones of $\beta$-1,4-endoglucanase gene were detected as the clear zones on a medium supplemented with carboxymethylcellulose (CMC). This transformant possessed a single plasmid, designated pDS1, which contained the vector DNA and a 3.5 kilobase (kb) Sau3AI insertion fragment encoding endoglucanase. The size of the cloned fragment was reduced to 2.0 kb. The endoglucanase activity produced by the E. coli DH5$\alpha$ (pDS6) was higher than that of Actinomyces sp. 40 strain. The optimum pH and temperature of the cloned enzyme were pH 4.0$\sim$5.0 and 55$^{\circ}C$, respectively. The cloned enzyme was stable at 55$^{\circ}C$ or below and in buffer ranging from pH 4.0 to 7.0. The enzyme degraded CMC but did not degrade xylan, cellobiose, and methyl-umbelliferylcellobiopyranoside (MUC).

• Environmental Analysis Health and Toxicology
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• v.18 no.2
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• pp.137-143
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• 2003

To validate and to estimate the chemical hazard playa very important role to environment and human health. The detection of many synthetic chemicals used in industry that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this resepct, the clastogenicity of 8 synthetic chemicals was evaluated with bone marrow micronucleus assay in mice. The positive control, mitomycin C(2mg/kg,i.p.) revealed significant induction ratio of percentage of micronucleated polychromatic erythrocytes/l,000 polychromatic erythrocytes compared to carboxymethylcellulose control. The chemicals with relatively high LD$\_$50/ value such as phenylisocyanate (CAS No. 103-71-9), m-aminochlorobenzene (CAS No. 108-42-9) and 2-chloro-4-nitroaniline (CAS No. 121-87-9) revealed no significant induction of micronucleated polychromatic erythrocytes in mice. From this results, 8 synthetic chemicals widely used in industry have revealed no significant micronucleus induction of clastogenicity in mice in this experiment.

• Applied Biological Chemistry
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• v.35 no.3
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• pp.173-178
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• 1992

A bacterium having CMCase activity was isolated form soil and identifed as a Pseudomonas sp YD-15. The optimum conditions for the production of CMCase were avicel 1.2%, yeast extract 0.5%, $KNO_3$ 0.06%, $K_2HPO_4$ 0.2%, $MgSO_4$ $7H_2O$ 0.15%, pH 8.0, $30^{\circ}C$ and 60 hours cultivation. The CMCase was purified 15.2 folds with 14ft yield through ammonium sulfate precipitation, DEAE-sepharose column chromatography and sephadex G-100 gel filtration chromatography. The optimum pH and temperature for the enzyme activity were 6.0 and $50^{\circ}C$, respectively. The enzyme was stable between pH 5.0 and 8.0, below $50^{\circ}C$. The molecular weight was calculated about 100,000 by SDS-polyacrylamide gel electrophoresis. $K_m$ value for CMC used as a substrate was 40 mg/ml.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.356-364
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• 2016

In vivo genotoxic potential of isoquercetin, a plant common flavonoid, in comparison with quercetin was investigated for the DNA breakage and the clastogenicity endpoints. Male ICR mice were administered by oral gavage for 3 days with $3{\times}0.5%$ carboxymethyl cellulose (CMC), 3 ${\times}$ isoquercetin (250, 500 mg/kg/day), 3 ${\times}$ quercetin (250, 500 mg/kg/day) and 2 ${\times}$ ethyl methanesulfonate (EMS, 200 mg/kg/day). Tissues were collected 48 hours after the first treatment and within 3 hours after the last treatment. The DNA damages were evaluated using Comet assay in liver and stomach, while the clastogenicities were determined using micronucleus test in bone marrow of same animals. The treatment of isoquercetin as well as quercetin did not cause the DNA damages in liver and stomach, and not induce the frequencies of micronucleus polychromatic erythrocytes in bone marrow. In conclusion, isoquercetin as well as quercetin did not cause the DNA breakages and the chromosomal damages in vivo system in these study conditions.

• Journal of the Korean Wood Science and Technology
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• v.18 no.2
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• pp.25-35
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• 1990

To investigate the effects of swelling treatment by ammonia on characteristics of carboxymethy1cellulose(CMC) and CMC solution, the domestic kraft pulp pretreated with 5%, 10%, 15% and 20% $NH_4OH$ solution, was carboxymethylated by the standard method, and then the CMC prepared was tested. The physical properties of CMC and CMC solution, such as degree of substitution, transparency. viscosity, weight increase and solubility, were measured, and the comparison with commercial domestic CMC used as a food additive was done. The results obtained were as follows; 1. In CMC manufactured by standard solvent method, hardwood bleached kraft pulp(LBKP) was more substituted than safwood bleached kraft pulp(NBKP), and viscosity of NBKP was higher than that of LBKP. 2. When ammonia swelling treatment was done, degree of substitution gradually decreased with increasing concentration of $NH_4OH$, and degree of substitution of LBKP decreased with a larger range than that of NBKP. 3. When ammonia swelling treatment was done. transparency of CMC solution from LBKP was hardly effected, but in case of NBKP gradually increased with increasing concentration of $NH_4OH$. 4. When ammonia swelling treatment was done, viscosity of CMC solution was higher than that of CMC solution without ammonia swelling treatment. Especially, CMC of high viscosity could be manufactured in 5%, 10% concentration levels of $NH_4OH$. 5. In CMC manufactured from domestic NBKP, CMC at the range of 0.40 to 0.50 in DS was dispersed easily and quickly dissolved, and CMC at more than 0.50 in DS was dispersed slowly in water solution. 6. In comparison with commercial domestic CMC used as a food additive, CMC manufactured from domestic NBKP was higher in DS, and was lower in viscosity and transparency.

• BMB Reports
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• v.39 no.1
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• pp.105-110
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• 2006

We have screened 766 strains of fungi from the BIOTEC Culture Collection (BCC) for xylanases working in extreme pH and/or high temperature conditions, the so-called extreme xylanases. From a total number of 32 strains producing extreme xylanases, the strain BCC7928, identified by using the internal transcribed spacer (ITS) sequence of rRNA to be a Marasmius sp., was chosen for further characterization because of its high xylanolytic activity at temperature as high as $90^{\circ}C$. The crude enzyme possessed high thermostability and pH stability. Purification of this xylanase was carried out using an anion exchanger followed by hydrophobic interaction chromatography, yielding the enzyme with >90% homogeneity. The molecular mass of the enzyme was approximately 40 kDa. The purified enzyme retained broad working pH range of 4-8 and optimal temperature of $90^{\circ}C$. When using xylan from birchwood as substrate, it exhibits $K_m$ and $V_{max}$ values of $2.6{\pm}0.6\;mg/ml$ and $428{\pm}26\;U/mg$, respectively. The enzyme rapidly hydrolysed xylans from birchwood, beechwood, and exhibited lower activity on xylan from wheatbran, or celluloses from carboxymethylcellulose and Avicel. The purified enzyme was highly stable at temperature ranges from 50 to $70^{\circ}C$. It retained 84% of its maximal activity after incubation in standard buffer containing 1% xylan substrate at $70^{\circ}C$ for 3 h. This thermostable xylanase should therefore be useful for several industrial applications, such as agricultural, food and biofuel.

• Journal of Nutrition and Health
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• v.23 no.7
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• pp.492-503
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• 1990

This study was performed to investigate nutritional effect of various dietary fibers on lead absorption, and protein and lipid metabolisms in growing rats. Sixty male rats of Sprague-Dawley strain weighing 140$\pm$1.1g were blocked into 10 groups according to body weight and fed 10 kinds of diet different with fiber sources [non-fiber, cellulose, pectin, guar gum or carboxymethylcellulose(CMC)] and lead levels (0 or 1%) for 4 weeks. Results were summerized as follows : 1) Food intake, weight gain, FER and PER were remarkably decreased in lead(Pb)-added groups. Weight gain, FER and PER in Pb-added pectin group were significantly lower than those in Pb-added non-fiber group. 2) Liver and kidney weights, femur weight and length, hematocrit and hemoglobin content were decreased in Pb-added groups. Especially femur and liver weights in pectin groups were the lowest among groups. 3) Total protein content in serum was significantly decreased in Pb-added groups but was not different with dietary fiber sources. Total lipid content in serum was not different with dietary Pb levels and fiber sources, but cholesterol content in serum of guar gum group was significantly decreased by Pb addition. 4) Nitrogen, lipid and cholesteol contents in liver were significantly decreased in Pb-added groups, and lipid content in liver of pectin and CMC groups was lower than other groups. 5) Daily urinary and fecal excretions of nitrogen, kipid and cholesterol were decreased in Pb-added groups, and fecal nitrogen was significantly increased in Pb-added groups, and fecal nitrogen of cellulose and guar gum groups was significantly higher than other groups. Fecal excretions of lipid and cholesterol were increased by dietary fibers, and especially fecal lipid was remarkably increased in pectin and guar hum group. 6) Pb contents in liver and femur were decreased by dietary fibers. Especially Pb contents in liver, kidney and femur were significantly decreased in guar gum group. 7) Daily urinary and fecal excretions of Pb were significantly increased in cellulose and guar gum groups, and fecla excretion of Pb in guar gum group was twice of non-fiber group. Pb absorption ratio was significantly decreased in guar gum group. In conclusion, dietary fibers have effect on protein and lipid metabolisms, and decreased intestinal absorption of Pb by increasing fecal excretion. But the degree of effect was different with dietary fiber sources.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.296-303
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• 1993

Response surface methodology was employed to investigate the conditions for separating water-soluble proteins from egg yolk using sodium alginate, propylene glycol alginate (PGA), sodium carboxymethylcellulose (CMC) and pectin which are approved as food additives. Effects of plysaccharide concentration and pH of the reaction system on protein and lipid contents in the supernatant were evaluated at respectively five and three levels of concentration and pH using rotatable hexagon design. Statistical analysis showed that pH of the system was a more important factor than polysaccharide concentration as it significantly affected all two responses. Separating conditions established by a graphical optimization technique were $0.23{\sim}0.25%$ of sodium alginate at $pH\;5.9{\sim}6.0$, $0.15{\sim}0.17%$ of PGA at $pH\;4.3{\sim}4.5$, $0.30{\sim}0.25%$ of CMC at pH 3.0, and $0.09{\sim}0.10%$ of pectin at $pH\;5.6{\sim}5.8%$.