• Microbiology and Biotechnology Letters
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• v.9 no.2
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• pp.65-69
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• 1981

As a process to utilize agricultural residues, simultaneous hydrolysis-fermentation (SSF) was compared with fermentation of enzymic hydrolyzate using koji cultures of Trichoderma sp. KI 7-2 and a thermotolerant yeast Saccharomyces cerevisiae NCYC 716. Cellobiose was not detected in SSF broth whilst 15 mg/$m\ell$ of the disaccharide was found in enzymic hydrolysate of rice straw using the same enzyme source. It was found that converting glucose to ethanol in SSF process reactivated the cellobiase activity, which is inhibited by the accumulation of glucose in enzymic hydrolysis process. Cutting milled rice straw was fermented as effectively as ball milled one in SSF process. From tile results discussions are made on the product inhibition mechanism of cllulolytic enzyme system.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.257-262
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• 2009

Carboxymethyl celluase (cellulase) was purified from cell-free extract of the recombinant Escherichia coli carrying a Bacillus licheniformis WL-12 cellulase gene by DEAE-Sepharose and phenyl-Sepharose column chromatography with specific activity of 163 U/mg protein. The molecular mass of the purified enzyme was estimated to be approximately 49.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme had a pH optimum at 5.5 and a temperature optimum at $55^{\circ}C$. The activity of the enzyme was completely inhibited by SDS (5 mM), and slightly enhanced by $Cu^{2+}$ (5 mM). The cellulase was active on CMC, konjac, barely glucan and lichenan, while it did not exhibit activity towards xylan, locust bean gum, and p-nitrophenyl-$\beta$-glucopyranoside. The predominant products resulting from the cellulase hydrolysis were cellobiose and cellotriose for cellooligosaccharides including cellotriose, cellotetraose and cellopentaose. The enzyme could hydrolyze cellooligosaccharides larger than cellobiose.

• The Korean Journal of Mycology
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• v.14 no.4
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• pp.257-263
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• 1986

So as to clarify the biodegradation mechanism of lignin, lignin biodegradability among four white-rot fungi, Pleurotus ostreatus 1,2,3, and Polyporus versicolor were compared each other by simple plate test method, so that P. ostreatus 2 and P. versicolor exhibited the most wide clear zone. And to investigate the degree of lignin depolymerization, they were grown in lignin­media where various carbohydrates were added, then that was analyzed through column chromato­graphy. In consequence, P. ostreatus 2 and 3 showed more excellent effect of lignin depolymerization among those 4 white-rot fungi, and also in culture media in which glucose, cellobiose and xylose were added. When culture filtrates of the same media were scanned at UV range, there were no peak at 280 nm in the culture filtrate of P. ostreatus 2 and 3 where glucose, cellobiose and xylose were added. At the same time, culture filtrate, in which lignin was only contained as a carbon source, showed browning in color, whereas culture media with glucose, cellobiose and xylose in addition to lignin became yellowish (that is, decolorization). From above results, it might be assumed that polymerization and browning of lignin were decreased and lignin biodegradability was increased, when grown in lignin media where various carbohydrates were added.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.524.1-524
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• 1986

CMCase, a member of cellulose decomposing enzymes, hydrolyze cellulose up to cellobiose. Cellobiase splits cellobiose to glucose units. Therefore, a linkage of the twogenes coding for CMCase and cellobiase on the same plasmid is needed to produce a cellulase complex which can produce glucose from cellulose. A genetic operon in which the two structural genes are under the control of a single promoter would be ideal for this purpose. The present report is on the linking of the two cellulase genes in one plasmid as a preliminary step of the operon construction.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.583-586
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• 2000

Many different oligosaccharides were produced by transferring the fructose residue of sucrose to maltose, cellobiose, lactose and sucrose (self-transfer), where their yields of fructosylated acceptor products accounted for $26{\sim}30%$ (w/w). The maximum conversion yield (30%) was obtained in fructosyl cellobioside formation with 500 g sucrose/l (substrate) and 200 g cellobiose/l (acceptor). These four acceptors gave various products having DP (degree of polymerization) $2{\sim}7$ by successive transfer reactions.

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.226-231
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• 1998

The medium optimization was investigated to maximize the production of fibrinolytic enzyme by Bacillus subtilis KCK-7 isolated from Chungkookjang, which could hydrolyze the fibrin produced through the blood coagulation mechanism in human body. The simultaneous addition of 5% soluble starch and 0.5% cellobiose to the medium as carbon sources resulted in the highest production of the fibrinolytic enzyme. Likewise, the optimized composition of medium appeared to be 0.5% peptone, 0.3% beef extract, 0.5% cellobiose, 5% soluble starch, 2% raw soybean meal and 0.02% Na$_2$HPO$_4$. In addition, the fibrinolytic enzyme production by Bacillus subtilis KCK-7 reached to the maximum level after the cultivation for 48 hr, using the optimized medium.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.48-53
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• 2001

An in vitro study was conducted to examine the effect of sources and the addition levels of carbohydrates on fermentation characteristics, bacterial growth, and hydrogenation of linoleic acid ($C_{18:2}$) by mixed ruminal bacteria. Starch and cellobiose were added to the 200 ml non-selective basal media at the levels of 0.20 and 0.35% (w/v), respectively. Linoleic acid (66.8~79.6 mg) in the absorbed form into the pieces of nylon cloth was also added to the media of 5 treatments including control which was not added with carbohydrate. Three mls of rumen fluid strained through 12 layers of cheese cloth were added to each medium, and were incubated anaerobically in the shaking incubator of $39^{\circ}C$ for 24 hours. During 24 h incubation the pH in incubation media of all treatments was maintained above 6.6 by the addition of sodium bicarbonate. The pH and ammonia concentration of incubation media were not clearly influenced by the sources and addition levels of carbohydrates while additions of carbohydrates increased (p<0.0001) VFA concentration at the 24 h incubation. Molar proportions of acetate were reduced (p<0.0004) while those of propionate were increased (p<0.0006) by the addition of carbohydrates. But the differences in concentration and molar proportions of the VFA were small between the sources or the addition levels. Bacterial growth was faster (p<0.0004) in the starch added treatments than in the cellobiose added ones and control, but no differences were found between addition levels. Increased (p<0.0487) hydrogenation was observed from the starch added treatments compared to the cellobiose added ones, but there was no difference between addition levels.

• KSBB Journal
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• v.15 no.1
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• pp.9-13
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• 2000

In order to determine the characteristics of $\beta$-glucosidase associated with cellulose degradation, the enzyme produced extracellularly by the mycelia of Tricholoma matsutake DGUM 26001 in culture broth was partially purified. The enzyme activity was maintained in the range of temperatures trom 55 to $70^{\circ}C$ and its optimum temperature was $65^{\circ}C$. The $\beta$-glucosidase enzyme showed relatively high activity in the range of pH 3.0-5.0 and its optimum pH was 4.0. Under the optimal conditions, the specific activity of $\beta$-glucosidase for salicin as a substrate was 18.7 unit/mg protein. After thermal treatment of the enzyme at $55^{\circ}C$ for 60 min, more than 90% of the enzyme activity was still sustained. Iron($Fe^{++}$) stimulated enzyme activity, whereas mercury($Hg^{++}$) and copper($Cu^{++}$) inhibited. Compared to salicin as a substrate, the relative activity for cellobiose was observed to be 48.6%. The apparent $K_m$ and $V_{max}$ of the enzyme with cellobiose were 0.12 mM and 0.02 umol/min, respectively.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.933-941
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• 2008

An extracellular $\beta$-glucosidase produced by Monascus purpureus NRRL1992 in submerged cultivation was purified by acetone precipitation, gel filtration, and hydrophobic interaction chromatography, resulting in a purification factor of 92-fold. A $2^2$ central-composite design (CCD) was performed to find the best temperature and pH conditions for enzyme activity. Maximum activity was observed in a wide range of temperature and pH values, with optimal conditions set at $50^{\circ}C$ and pH 5.5. The $\beta$-glucosidase showed moderate thermostability, was inhibited by $HgCl_2$, $K_2Cr_O_4$, and $K_2Cr_2O_7$, whereas other reagents including $\beta$-mercaptoethanol, SDS, and EDTA showed no effect. Activity was slightly stimulated by low concentrations of ethanol and methanol. Hydrolysis of p-nitrophenyl-$\beta$-D-glucopyranoside (pNPG), cellobiose, salicin, n-octyl-$\beta$-D-glucopyranoside, and maltose indicates that the $\beta$-glucosidase has broad substrate specificity. Apparently, glucosyl residues were removed from the nonreducing end of p-nitrophenyl-$\beta$-D-cellobiose. $\beta$-Glucosidase affinity and hydrolytic efficiency were higher for pNPG, followed by maltose and cellobiose. Glucose and cellobiose competitively inhibited pNPG hydrolysis.

• Korean Journal of Microbiology
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• v.36 no.3
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• pp.181-186
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• 2000

The cellulosome of Clo.~tr~rlil~m tl\ulcornererfnocellum consistmg of 26 dfferent polypeptides contains calcium. The polypeptides dissociated when calcium was removed. Most of dockerill region in the catalytic polypeptides cleavcd during dmociation. The dissociated polypeptides were well separated by MonoQ column chromatography into CipA containing fraction, a fraction still complexed wit11 91 kDa (CelK-a). 60 IiDa and 57 kDa polypeptides, and fractious contailling mainly single polypeptide of 46 kDa (CelA-a) or 71 1d)a polypeptide (CelS-trj Most or the fractions hydrolyzed c~ystalliue cellulose The purified 71 kDa polypeptide was strictly dependent on calcium for crystalline cellulose hydvolyzing activities a1 $60^{\circ}C$~$70^{\circ}C$ but 46 kDa polypeptide was not. 46 M)a polypeptide digested cellodextri~~ as cellobiose or cellotriose unit, and glucose was produced together with cellobiose and cellotriose froln cellotetraosc. It seems that cellulosome produces final product, cellobiose, through coordinated ~qulation of activities of vannus subunits.