• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.376-382
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• 1990

An extracellular cellulase producing bacterium YE-5 was isolated from soil, and identified as a Cellulomonas sp. by its taxonomical characteristics. The maximal activities of avicelase (0.35 units/ml), CMCase (3.18 units/ml), FPase (0.315 units/ml) and $\beta$-glucosidase (0.882 units/ml) were obtained when this strain was cultured for 48 hrs at $30^{\circ}C$ in a medium containing 0.8% (w/v) Solka floc, 0.06010 (wlv) urea, 0.1% (w/v) $K_2HP0_4$, 0.1% (w/v) $MgS0_4.7H2_0$, 0.2% (w/v) bacto peptone, 0.2% (w/v) yeast extract and pH 6.5. The cellulase was purified by ammonium sulfate fractionation, DEAE-Sepharose column chromatography and Sephadex 6-100 column chromatography from culture filtrate of Cellulomonus sp. YE-5. The molecular weights of purified avieelase, CMCase I, and CMCase II were estimated to be about 95,000 ~ 105,000, 46,000 ~ 47,000 and 120,000 ~ 125,000, respectively.

• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.86-90
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• 1993

CMCase positive clones were screened from Cellulomonas sp. YE-5 and named pCE1, pCE2 and pCE3. Among the positive clones pCE1 was used for this study, because it has the smallest insert and the highest CMCase activity among the 3 clones, and its nucleotide sequence was determined. The CMCase gene in pCE1 was composed of 1071 bp of nucleotides coding 357 amino acids. Computer analysis showed that the pCE1 has 65% sequence homology with the endoglucanase from Cellulomonas fimi.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.164-168
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• 1992

Enzymatic properties of avicelase, carboxymethyl cellulase (CMCase) and P-glucosidase produced by Cellulomonas sp. YE-5 were studied. Optimal temperature and pH of avicelase were 40t and 6.0, and those of CMCase and P-glucosidase were $45^{\circ}C$ and 6.5. Avicelase and CMCase were stable between pH 5.0 and 9.5, and &glucosidase was stable between pH 5.5 and 8.0. Avicelase and P-glucosidase were inactivated when incubated at $35^{\circ}C$ for 6 hrs, and CMCase was at $40^{\circ}C$ for 6 hrs. All cellulases were strongly inhibited by $Cu^{2+} \; and \; Zn^{2+}. K_m$ values of avicelase for avicel, CMCase I and CMCase II for CM-cellulose, and ($\beta$-glucosidase for p-nitrophenyl-$\beta$-D-glucoside (PNPG) were 4.76, 16.4, 16.4 $\mu g$/ml and 3.51 mM, respectively.

• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.174-179
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• 1997

CMCase produced by recombinant E. coli JM109 (pCEH#4) containing CMCase gene from Cellulomonas sp. YE-5 was purified to 24.3 fold and 2.6% yield by ammoniumsulfate precipitation, DEAE-cellulose column chromatography and gel filtration on Sephadex G-100. The optimum pH and temperature for CMCase activity were pH 7.0 and 5$0^{\circ}C$. The enzyme was stable between pH 5.0 and 10.0, and up to 6$0^{\circ}C$. The molecular weight of he enzyme was estimated to be approximately 40,000 daltons by SDS-PAGE. Analysis of the amino acid composition showed that the enzyme contained many glycines and acidic amino acids. The enzyme was an endo-type CMCase and the final enzyme reaction product from hydrolysis of Cm-cellulose by the enzyme was cellobiose. {TEX}$K_{M}${/TEX} value determined with CM-cellulose was 1.28mM.