• 산업식품공학
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• 제14권3호
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• pp.243-248
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• 2010

${\beta}$-Glucosidase 효소활성이 높은 균주를 선발하기 위하여 다양한 김치에서 분리된 젖산균의 ${\beta}$-glucosidase 활성을 탐색하였다. 김치에서 분리된 156개의 젖산균 중 134개의 균주만이 cellobiose를 탄소원으로 대사하였으며, 세포내 ${\beta}$-glucosidase 활성이 세포외 활성보다 현저히 높았다. 배추김치에서 분리된 W. cibaria KFRI88010 균주가 3.7${\pm}$0.5 unit/mg protein으로서 가장 높은 세포내 ${\beta}$-glucosidase 효소활성을 나타내었으며, 효소활성은 pH 5, ${37^{\circ}C}$ 반응조건에서 가장 높게 나타났다. $Mn^{2+}$를 비롯한 금속이온은 효소활성을 크게 저해하였다. W. cibaria KFRI88010 균주를 배양할 때 사용한 탄소원 중, fructose는 cellobiose나 glucose와 비교하여 약 2.5배 이상의 높은 세포내 ${\beta}$-glucosidase 효소활성을 나타내었다.

• 아시안잔디학회지
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• 제12권4호
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• pp.211-220
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• 1998

Cellulose-degrading fungi were idenfied as Rhizoctonia solani AG2-2(IV), T. harzianum and C. cochliodes. Rhizoctonia solani AG2-2(IV) grows better in the acidified media of pH 4 and 5 than pH 6 and 7. Mycelial growth of T. harzianum and C. cochliodes was also higher in pH 4 and 5 than in pH 6 and 7. In order to relate the above findings to nutrient utilization, mycelial growth of R. solani AG2-2(IV) are evaluated with various carbon sources. R. solani AG2-2(IV) grows well in the order of mannose, cellobiose, glucose, xylose and arabinose. However, mycelial dry weights of T. harzianum were 98.7, 78.0, 72.3, 43.7 and 32.3mg in glucose, mannose, cellobiose, xylose, and arabinose, respectively. Mycelial dry weight of C. cochilodes was 118, 65, 57, 49, and 16mg in mannose, cellobiose, xylose, glucose, and arabinose, respectively. Result of cellulase assay of R. solani AG2-2(IV) and soil fungi was reffered as, R. solani AG2-2(IV) produced more cellulase on CMC substrate than on CEL and secretes more enzyme in floated condition than in water-immersed condition. T. harzianum secreted less amount of cellulase than R. solani AG2-2 and C. cochliodes. T. harzianum produced no enzyme on CEL under water-immersed condition. C. cochliodes produced similar amounts of cellulase on either CMC or CEL under both water-immersed and floated condition.

• 미생물학회지
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• 제22권3호
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• pp.167-173
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• 1984

The cellabiase (${\beta}$-glucosidase) gene in a Cellulomonas sp. CS1-1 was cloned into E. coli HB101 using the vector plasmid pBR322, and the expression of the gene in E. coli studied. The chromosomal DNA of the cellulomonas was digested by seveal restriction enzymes, each of which has only one cleaving site in plasmid pBR322. The recombinant plasmid, pSB2, created with Sal I frament, was expressed for the cellobiase gene in E. coli. The recombiant plasmid was estimated to contain 6.4 Kb foreign DNA at the Sal I site of plasmid pBR322 and the inserted DNA was mapped by single and double digestion with several enzymes. E. coli HB101(pSB2) has slowly grown in a mineral liquid medium containing cellobiose as a sole carbon source. The cellobiase activity in the transformed E. coli was 132 units per liter, which is equivalent to one twenty fifth of that in doner strain Cellulomonas sp. CS1-1. The transforned cell with plasmid containing cellulase gene grow well in the LB mediuns. The synthesis of cellobiase in the strain, E. coli HB101 (pSB2), was inhibited by glucose and at high concentration of cellobiose, and induced by cellobiose at low concentration.

• Journal of Microbiology and Biotechnology
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• 제29권6호
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• pp.905-912
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• 2019

Bioethanol has attracted much attention in recent decades as a sustainable and environmentally friendly alternative energy source. In this study, we compared the production of bioethanol by Candida molischiana and Saccharomyces cerevisiae at different initial concentrations of cellobiose and glucose. The results showed that C. molischiana can utilize both glucose and cellobiose, whereas S. cerevisiae can only utilize glucose. The ethanol yields were 43-51% from different initial concentrations of carbon source. In addition, different concentrations of microcrystalline cellulose (Avicel) were directly converted to ethanol by a combination of Trichoderma reesei and two yeasts. Cellulose was first hydrolyzed by a fully enzymatic saccharification process using T. reesei cellulases, and the reducing sugars and glucose produced during the process were further used as carbon source for bioethanol production by C. molischiana or S. cerevisiae. Sequential culture of T. reesei and two yeasts revealed that C. molischiana was more efficient for bioconversion of sugars to ethanol than S. cerevisiae. When 20 g/l Avicel was used as a carbon source, the maximum reducing sugar, glucose, and ethanol yields were 42%, 26%, and 20%, respectively. The maximum concentrations of reducing sugar, glucose, and ethanol were 10.9, 8.57, and 5.95 g/l, respectively, at 120 h by the combination of T. reesei and C. molischiana from 50 g/l Avicel.

• Korean Chemical Engineering Research
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• 제49권1호
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• pp.101-104
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• 2011

Hemoflavoenzyme으로서 cellobiose dehydrogenase(CDH)는 셀룰로오스를 분해하는 과정에서 세포 외부로 분비되는 효소로서 amorphous cellulose와 강하게 결합하여 셀룰라아제(cellulase)에 의해 microcrystalline cellulose의 가수분해를 증가시킨다. 따라서 CDH는 바이오 에탄올 생산의 당화공정에서 중요한 역할을 할 것으로 예상된다. 여러 백색부후균으로부터 CDH 생산이 높은 Phanerochaete chrysosporium ATCC 32629 균주를 선정하였으며, 균주로부터 생산된 CDH 효소활성의 최적 온도와 pH는 각각 ${55^{\circ}C}$와 4이었다. CDH 활성을 증가시키기 위하여 P. chrysosporium ATCC 32629 균주를 돌연변이시켰다. 돌연변이는 새로운 시도로써 국부적으로 큰 에너지를 줄 수 있는 특징을 가진 양성자 빔을 이용하였다. 양성자 빔 조사 후 사멸율이 약 99.9%인 1.2 kGy에서 CDH 활성이 증가된 변이주를 얻었다. 선별된 변이주와 모균주를 액체배양했을 때 변이주가 모균주보다 CDH와 $\beta$-glucosidase 활성이 각각 약 1.4배와 20배 증가하였다. 따라서, CDH 뿐만 아니라 $\beta$-glucosidase 활성이 높은 P. chrysosporium 변이주를 확보하였다.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.457-466
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• 2024

Cellobiose dehydrogenases (CDHs) are a group of enzymes belonging to the hemoflavoenzyme group, which are mostly found in fungi. They play an important role in the production of acid sugar. In this research, CDH annotated from the actinobacterium Cellulomonas palmilytica EW123 (CpCDH) was cloned and characterized. The CpCDH exhibited a domain architecture resembling class-I CDH found in Basidiomycota. The cytochrome c and flavin-containing dehydrogenase domains in CpCDH showed an extra-long evolutionary distance compared to fungal CDH. The amino acid sequence of CpCDH revealed conservative catalytic amino acids and a distinct flavin adenine dinucleotide region specific to CDH, setting it apart from closely related sequences. The physicochemical properties of CpCDH displayed optimal pH conditions similar to those of CDHs but differed in terms of optimal temperature. The CpCDH displayed excellent enzymatic activity at low temperatures (below 30℃), unlike other CDHs. Moreover, CpCDH showed the highest substrate specificity for disaccharides such as cellobiose and lactose, which contain a glucose molecule at the non-reducing end. The catalytic efficiency of CpCDH for cellobiose and lactose were 2.05 × 10⁵ and 9.06 × 10⁴ (M^-1 s^-1), respectively. The result from the Fourier-transform infrared spectroscopy (FT-IR) spectra confirmed the presence of cellobionic and lactobionic acids as the oxidative products of CpCDH. This study establishes CpCDH as a novel and attractive bacterial CDH, representing the first report of its kind in the Cellulomonas genus.

• 주류공업
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• 제15권2호
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• pp.48-57
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• 1995

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.115-120
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• 1997

Penicillium sp.-L4, a causative fungus of rot in citrus fruits, was isolated and its mode of hydrolytic enzyme production was investigated. Carboxymethylcellulase (CMCase), polygalacturonase(PGase), extra- & intra-cellular $\beta$-glucosidase and cellobiase were produced drastically by addition of substrates in minimal media. Production of the hydrolytic enzymes were induced efficiently by cellobiose and cellooligosaccharides which were the products of cellulose hydrolysis, but repressed by addition of mono-saccharide such as glucose, raffinose, galacturonic acid. The relative activity of p-nitrophenyl-$\beta$-D-glucopyranoside(PNPG) hydrolysis was higher than that of cellobiose hydrolysis in extracellular enzymes, and reverse is true in intracellular enzymes. Intact enzyme production of P. sp.-L4 on lemon peel lesion was sequential. $\beta$-Glucosidase and CMCase were produced first and followed by PGase. The enzyme productivities and pH in lesions were coincident with optimal pH of each enzyme activities.

• 펄프종이기술
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• 제31권2호
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• pp.1-7
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• 1999

In this paper, five lignin model compounds (vanilly alcohol, veratryl alcohol, veratryl methyl carbinol, biseugenol) and three cellulose model compounds (${\alpha}$-D-glucos, methyl-${\beta}$-D-glucopyra-noside, D-cellobiose) were used to study the degradation rates of lignin and cellulose with chlorine dioxide. Biseugenol, which has unsaturated structure on the side chain of aromatic ring, was found to react with chlorine dioxide very quickly and consume large amount of chlorine dioxide. Phenolic structures, represented by veratryl alcohol and apocynol, react with chlorine dioxide much faster than nonphenolic structures represented by veratryl alcohol and veratryl methyl carbinol. The degradations of cellulose models were generally very slight, the corder of reaction rate being ${\alpha}$-D-glucose > D-cellobiose > methyl-${\alpha}$-D-glucopyranoside.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.179-182
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• 2001

Two intracellular enzymes, cellobiose phosphorylase (CBP) and cellodextrin phosphorylase (CDP) are involved in the phosphorolytic pathway in cellulose degradation. Those enzymes are considered to be useful in syntheses of oligosaccharides because the reactions are reversible. CBP from Cellvibrio gilvus and CDP from Clostridium thermocellum YM-4 were cloned and over-expressed in Escharichia coli. Both the enzyme reactions showed ordered bi bi mechanism. Acceptor specificity of CBP in the reverse reaction was determined. Several $\beta$-l,4-glucosyl disaccharides were synthesized by using the reaction. A new substrate inhibition pattern, competitive substrate inhibition, was also found in the reverse reaction of CBP Cellobiose was produced from sucrose at a high yield by a combined action of three enzymes including CBP