• 펄프종이기술
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• 제36권5호
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• pp.53-61
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• 2004

[ $Poly(_{D}-ldactide)\;(_{D}-PLA)$ ] was synthesized to have low molecular weight for miscible blends with a high molecular $poly(_{L}-lactide)\;(_{L} -PLA)$. The blends were prepared by dissolving the two components of $_{L}-PLA\;and\;_{D}-PLA\;(w/w)$ in chloroform (l00/0, 90/10, 70/30, 50/50, 30/70, 0/100). The miscibility of these miscible blends was characterized by gel-permeation chromatography (GPC), differential scanning calorimetry (DSC), and the selective degradability by enzymes (proteinase K, subtilisin and $\alpha$-chymotrypsin). The coating efficiency of PLA blends onto paper was determined and the degrading activity cellulases by on these blends. The miscibility, coating efficiency and enzymatic degradability of these blends were decreased according to increasing of $_{D}-PLA$ blending part. Such results were attributed to the extent of coating application of PLA, with better miscibility (compatibility), coating efficiency and degradability due to a higher $_{L}-PLA$ content.

• 미생물학회지
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• 제17권2호
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• pp.58-64
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• 1979

Studies on some properties of cellulase isolated from Piricularia oryzae. Crude cellulases were prepared from dried rice plant powder (Tong-il, Pal-dal) culture of P. oryzae(N-2, C-8, T-2). The best yield of enzyme was obtained from the medium using Tong-il rice plant powder for P. oryzae cav. N-2 and 2%-sucrose concentration in preculture media. Two units of the enzyme were incubated at $60^{\circ}C$ for 1 hour with 1.0ml, 0.6% Na-CMC. The optimum temperature for the enzyme activity was at $60^{\circ}C$ and the optimum pH was at pH4.0. When Na-CMC was used as substrate the $K_m$ values of crude enzyme were calculated to be $1.05{\times}10^{-4}\;mM\;and\;V_{max}$ was 2.8 mmole/hour. A 10-fold partial purification was achieved by $(NH_4)_2SO_4$ precipitation followed by column chromatography on DEAE Sephadex A-25.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.529-532
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• 2006

Recently the production of ethanol from lignocecllulosics has received much attention due to immense potential for conversion of renewable biometerials into biofuels and chemicals. Fomitopsis palustris causes a typycal brown-rot and is unusual in that it rapidly depolymerize the cellulose in wood without removing the surrounding lignin that normally prevents microbial attack. This study demonstrated that the brown rot basidiomycete F. palustris was able to degrade crystalline cellulose. This fungus could also produce the three major cellulases (BGL, EXG and EG) when the cells were grown on 2.0% Avicel. The fungus was able to degrade both the crystalline and amorphous forms of cellulose from woody biomasses. Moreover, we found that this fungus has the processive EG like CBH which are able to degrade the crystalline region of cellulose. To establish the cellulase system in relation with degradation of woody biomass, we performed that purification, characterization and molecular cloning of a BGL, EGs and GLA from F. palustris grown on Avicel.

• 펄프종이기술
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• 제31권3호
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• pp.68-76
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• 1999

Coprinus cinereus 2249 producing alkaline-active cellulase was screened from 29 species of Corpinaceae and constitutively produced alkaline carboxymethyl cellulase (CMCase) and filter paper cellulase (Fpase). When cultivated at pH 9.0, 25$^{\circ}C$ and 5 days, copnnus cinereus 2249 produced higher alkaline activity on 0.5% CMC, 2% wheat bran as carbon source and 0.5% peptone, 0.05% yeast extract as nitrongen source compared with other culture conditions. The level of cellulase production was higher in the presence of wheat bran than in the presence of CMC. The optimum temperature and pH for alkaline -active cellulase activity weas 50$^{\circ}C$ and 9, 0, respectively.

• 한국미생물·생명공학회지
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• 제25권6호
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• pp.546-551
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• 1997

A bacterium producing the extracellular cellulases was isolated from soil and has been identified as Bacillus sp. The isolate, named Bacillus sp. 79-23, was shown to be very similar to B. subtilis on the basis of its biochemical properties. The carboxymethyl cellulase (CMCase) of culture supernatant was most active at 60$\circ$C and pH 6.0, and retained 90% of its maximum activity at pH 7.0. The additional carbon sources affected the CMCase productivity than nitrogen sources in the culture medium. The carbon sources including wheat bran, rice straw, maltose and glucose increased the enzyme productivty. Especially, the maximum CMCase production was 5.2 units/ml in LB medium supplemented with 3% (w/v) wheat bran, which was 13-folds more than that in LB medium. It was found that the enzyme production was in association with the growth of Bacillius sp. 79-23. But, whean bran did not affect the growth of isolate, suggesting that increasement of CMCase production was owing to the induction of CMCase biosynthesis by wheat bran. In addition, both water-soluble and insoluble components of wheat bran was involved in induction of CMCase biosynthesis.

• 한국미생물·생명공학회지
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• 제25권5호
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• pp.468-476
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• 1997

Soft-rot bacterial pathogen, Erwinia sp., was isolated from chinese cabbage tissue showing soft-rot symptom. This bacterial strain caused soft-rot to chinese cabbage and potato, and it was identified as Erwinia carotovora subsp. carotovora LY34 (E. c. subsp. carotovora LY34). Erwinia carotovora subsp. carotovora LY34 did not have hemicellulase but extracellular cellulase, pectinase, polygalacturonase, protease activity. The results of the microscopy showed that chinese cabbage tissue and potato tissue were macerated by infection of E. c. subsp. carotovora LY34. In analysis of the cellulases activity of the isolated cellulose-degradation enzymes from E. c. subsp. carotovora LY34 total protein, three cellulase activity bands were detected by non-denaturation gel electrophoresis method and five cellulase activity bands were detected by CMC-SDS-PAGE direct stain method.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.250-255
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• 2005

높은 원가인 펩톤을 다른 질소원으로 대체하기 위하여 콩 혹은 효모의 질소원 대체가능성을 검토한 결과 효모의 농도를 0.5%의 펩톤과 동등한 양의 질소원으로 하였을 때 amylase의 생산성이 2.30 U/ml로써 가장 높았다. 때문에 높은 원가의 펩톤을 효모로 대체하는 것이 가능할 것으로 사료된다.

• 한국양식학회지
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• 제9권4호
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• pp.453-459
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• 1996

Cellulase was purified from marine rotifer, Brachionus plicatilis, to homogeneity by using chromatographic methods. Purified enzyme is an endo-${\beta}$-1,4 glucanase and shows a strong hydrolytic activity against carboxymethyl (CM) -cellulose. The physicochemical parameters of enzyme activity were determined. The molecular weight of the purified protein was approximately 62 kDa as determined by SDS-polyacrylamide gel electrophoresis. The enzymatic capability to digest cellulose of Chlorella cell wall was compared with that of other well known cellulases from Thermomonospora fusca. Experiments involving Chlorella digestion indicated that CM-cellulase from marine rotifer, Brachionus plicatilis, could digest Chlorella very efficiently while cellulase purified from Thermomonospora fusca did not. From the result here, we propose that the cellulolytic system from marine rotifer is responsible for the hydrolysis of cellulosic wall of Chlorella, probing that rotifer digests Chlorella as a major live food.

• 미생물학회지
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• 제29권3호
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• pp.184-188
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• 1991

Three strains of Clostridium thermocellum, JH01, JH20 and JH30 which are capable of producing ethanol directly from cellulose were isolated from composts. The morphological, cultural and physiological properties of the strains were similar to the ATCC type strain, except for carbon source utilization and degree of ethanol tolerance. All of the three isolates could use glucose and maltose as a sole carbon source and two of them, strains of JH01 and JH20 were three times more tolerant to ethanol than the ATCC type strain. Cellulases secreted by the isolated strains had higher activities than those of the ATCC type strain.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.573-581
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• 2009

The complex enzyme pool secreted by the phytopathogenic fungus Fusarium graminearum in response to glucose or hop cell wall material as sole carbon sources was analyzed. The biochemical characterization of the enzymes present in the supernatant of fungal cultures in the glucose medium revealed only 5 different glycosyl hydrolase activities; by contrast, when analyzing cultures in the cell wall medium, 17 different activities were detected. This dramatic increase reflects the adaptation of the fungus by the synthesis of enzymes targeting all layers of the cell wall. When the enzymes secreted in the presence of plant cell wall were used to hydrolyze pretreated crude plant material, high levels of monosaccharides were measured with yields approaching 50% of total sugars released by an acid hydrolysis process. This report is the first biochemical characterization of numerous cellulases, hemicellulases, and pectinases secreted by F. graminearum and demonstrates the usefulness of the described protein cocktail for efficient enzymatic degradation of plant cell wall.