• KSBB Journal
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• v.6 no.2
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• pp.167-174
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• 1991

Enzymatic cellulose hydrolysis depends on the several factors such as the structural features (CrI, particle size and surface area, etc.), the nature of cellulase enzyme system, the inhibitory effects of products, and enzyme deactivation. At the presence of products on the initial hydro- lysis rate of cellulose, cellobiose has more severe inhibitory effect than glucose. Othewise, the inhibition effect of products for adsorbed enzyme is related to the glucose and cellobiose conentration hyperbolically. Enzyme deactivation of FPA and ${\beta}-glucosidase$ were expressed by exponential decay profile.

• The Korean Journal of Mycology
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• v.26 no.2 s.85
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• pp.239-245
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• 1998

The feasibility of enzymatic hydrolysis of cellulosic materials is dependent on the cost of cellulase, which is strongly influenced by the selection of proper carbon source in the cellulase production medium. When solka floc was used as a carbon source for the production of cellulase by Trichoderma reesei Rut C-30, a maximum of 53.2 U/ml of CMCase activity (4.8 U/ml of FPase activity) was obtained with a concentration of 1 % of solka floc. The cellulase activity decreased to 50% in the presence of 0.5% of glucose in the medium. The production of cellulase was considerably enhanced when solka floc and wheat bran were used together as a carbon source. A medium which contained 1 % of solka floc and 3 % of wheat bran yielded highest cellulase activity: CMCase activity of 76 U/ml and FPase activity of 12.5 U/ml.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.162-166
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• 1985

Three isozymes of Carboxymethyl Cellulase $(FI^*,\;FII^*,\;FIII)$ and two fractious of ${\beta}-1,4-D-Cellobiohydrolase$(CI, CIl) from Aspergillus niger were purified by Sephadex G-150, DEAE-Sephadex and Sephadex G-75 column chromatography. From the results of enzymatic hydrolysis and X-ray diffraction, ${\beta}-1,4-D-Cellobiohyarolase$ has a high activity toward highly crystalline cellulose such as filter paper and acts synergistically with Cx enzyme.

• 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 The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.35-43
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• 2017

This study was to research the relationships between rice straw degradation and changes of fibrolytic bacteria population during the in vitro rumen fermentation. Dry matter(DM) digestion of rice straw and population of fibrolytic bacteria were measured at the 0. 4, 8, 12 and 48 hours during the incubation. The populations of F. succinogenes. R. albus and R. flavefaciens were defined as log copy number of 16S rDNA by technical method of Quantitative real-time PCR. Total population of F. succinogenes, R. flavefaciens and R. albus was sum of bactera attached on rice straw and suspended in medium. It's population was increased with incubation, reached top level of 29.0 Log copy No at the 24 hour and then decreased. In the meantime, DM digestion of rice straw showed the higher increasement from the 8 hour to the 24 hour than from the 0 hour to the 8 hour, and then a slowdown in increasing trend of digestibility. Attachments of F. succinogenes, R. flavefaciens and R. albus were detected immediately after start of in vitro rumen incubation. At the same time, the colonized bacterial share were respectively 34.5%, 84.4% and 67.9% in total population. All of them was reached the highest colonized bacterial share above 94.7% at the 4 hour incubation. However population of attached bacteria was shown the highest level at the 12 hour or the 24 hour incubation. Kinetics of colonization were formed area of top speed from the 12 hour to the 24 hour and respectively reached 10.33, 9.28 및 8.30 Log copy No/h/g DM at the 24 hour by F. succinogenes, R. flavefaciens and R. albus. The kinetics of rice straw degradation was formed top level of 0.95% DM/h at the 24 hour. The present results gave clear evidence that degradation of rice straw was increased with the development of total fibrolytic bacteria in process of rumen fermentation. Also, their attachment was largely occurred immediately after insertion of rice straw, the colonized bacteria was actively proliferated, and then degradation of rice straw was maximized.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.58-58
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• 2001

본 연구는 섬유소 분해효소 유전자 Cel D(Cellulase Digestion)가 도입된 형질전환 돼지 생산을 통하여 섬유소 함유 사료의 이용 효율을 증대시키고, 나아가 장기이식동물 및 고가의 의료용 단백질 생산가축을 개발하기 위한 원천기술 확보에 있다. 섬유소분해 유전자의 크로닝 및 조직 특이적 발현벡터를 개발하기 위하여, 우선 소의 위중 제4위 내의 미생물로부터 전체 유전자를 분리하였고, 이렇게 작성된 DNA library에서 섬유소분해 관련 유전자인 약 2.0 kb의 Cel D유전자를 크로닝하였으며, 췌장 특이적 발현 프로모터(rat elastase I: 약 200bp)를 크로닝한 후, 미세주입용 형질전환 재조합 벡터를 구축하기 위하여 rElastase I 프로모터 하류에 섬유소 분해 유전자(Cel D)를 연결하여 약 3.0 kb 크기의 재조합 벡터를 준비하였으며, 재조합 유전자를 1세포기 수정란 전핵내에 미세주입 하기 위해 Sal I과 BglII를 이용 유전자 단편을 만들었다. 구축된 유전자를 미세주입하기 위한 수정란을 회수하기위해 총68두의 돼지를 4-5두씩 분리사육하면서 발정동기화 및 과배란 유기를 위해 PG600, Altrenogest, FSH, hCG를 투여하였으며 hCG투여후 약54시간에 외과적 방법에 의해 총 1,359개의 수정란을 회수하였고, 이중 미세주입가능한 1세포기 수정란은 1,296개로 두당 평균 15.9개 였다. 1,296개의 1세포기 수정란 중에서 재조합 유전자(rE I-CelD)가 미세주입된 660개의 수정란을 32두의 수란돈에 외과적 방법에 의해 이식하였으며, 이식되어진 모돈 13두가 분만하여 40.6%의 임신율을 나타내었다. 이렇게 분만된 13두에서 총 65두(암:33두, 수:32두)의 자돈이 생산되었으며, 형질전환 여부를 판명하기 위해 자돈의 꼬리조직으로 부터 genomic DNA를 추출하고 PCR 검정을 실시하였다. PCR 검정 결과, 섬유소 분해 유전자가 도입된 자돈은 5두 이었으며, 그 결과를 Table에 나타내었다.(Table Omitted) Table 1 에서와 같이 섬유소 분해효소유전자가 형질전환된 자돈은 65마리 중 5마리로 7.69%의 형질전환율을 나타내었으며, 5마리의 자돈중 2두(암:1두, 수:1두)는 분만 후 즉시 폐사되었으며 2두(암:1두, 수:1두)는 86일령 그리고 14일령에 폐사하여 현재 1두(암)가 생존하여 섬유소 분해 사양 실험 중에 있다.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1019-1030
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• 2003

The study was conducted to isolate and identify highly fibrolytic anaerobic fungi from the guts of a Hanwoo steer and a Korean native goat, and then investigate the characterization of cellulolytic activity of an anaerobic fungus. Twenty-one anaerobic fungal colonies were isolated in the study, in which 16 colonies were isolated from the rumen contents of the Hanwoo steer and 5 colonies from the duodenal fluids of the Korean native goat. Four anaerobic fungi were selected based on higher cellulolytic enzyme activities to identify under a optical microscope. NLRI-M003 and -T004 belong to Neocallimastix genus and NLRI-M014 belongs to Piromyces genus based on the morphology of their thallus, sporangia, rhizoid and the number of flagella. NLRI-M001 appeared to be an unknown strain of anaerobic fungi due to its different morphology from existing types of anaerobic fungi, though the morpholgoy is similar to Orpinomyces sp. Supplementation of 2% anaerobic fungal culture(NLRI-M003) in rumen-mixed microorganisms increased in vitro DM degradability of rice straw and filter paper up to 4 and 11%, respectively, compared with non-supplementation(control). CMCase and xylanase activities in in vitro culture were also higher in 2% fungal supplementation than controls in both rice straw and filter paper substrates.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.505-510
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• 1992

An endo-$\beta$-1,4-glucanase gene of Clostridium thermocellum was cloned in Escherichia coli and was considered as a novel gene by comparison with the restriction patterns of the C. thermocellum cellulase genes so far reported. The endoglucanase from recombinant E. coli was purified by column chromatography after heat treatment. The purified enzyme was a monomer having molecular weight of 40,000. The enzyme hydrolyzed CMC to glucose and cello-oligosaccharides at :naximum activities at pH 5.0 and $65^{\circ}C$. One of the endproducts, glucose, showed no inhibitory effect on the enzyme activity, while the other endproduct, cellobiose, inhibited slightly. The values of $K_{m}$ and $V_{max}$ of the enzyme for CMC were 0.39% (w/v) and 268 Ulmg protein, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.60-67
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• 2014

The comparisons between cellulolytic bacteria adhesion on rice straw and fiber digestion in time course during rumen fermentation were studied in situ. The adhesions of cellulolytic bacteria, F. succinogenes. R. albus and R. flavefaciens, were measured by RT-PCR. When the rice straws were incubated at 0. 2, 4, 8, 12 and 24 hours of the in situ rumen, straw was degraded with increasing speed during the incubation and showed the highest disappearance increasing rate (DM g/h) from 8 to 12 hour. The adhesions of F. succinogenes, R. flavefaciens and R. albus were achieved above 80% in 1 hour of in situ rumen fermentation and then keep adhesive population up after the time of fermentation. When the in situ samples were collected at 0, 5, 10, 30 and 60 min to detect the early stages of adhesion on the rice straws ingested into rumen, the numberous adhesive colony of F. succinogenes, R. flavefaciens and R. albus were detected in 5 min. In case of rice straw treated with 0, 2, 4 and 8% NaOH, all of three cellulolytic bacteria showed the increasing trends of adhesion with increasing DM disappearance of rice straw by higher concentration of NaOH at 12 hour of in situ. However, there were showed respectively difference at 24 hour. The present results gave certain evidence that adhesion of cellulolytic bacteria is definitely achieved in early stage of roughage ingestion into rumen, their colony develop the stable communities on roughage in process of rumen fermentation and then fiber degradation is accelerated.

• Journal of Life Science
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• v.23 no.6
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• pp.757-769
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• 2013

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater, identified as Bacillus velezensis by analyses of 16S rDNA and partial sequences of the gyrA, and designated as B. velezensis A-68. The optimal conditions for production of CMCase by B. velezensis A-68 were established using response surface methodology (RSM). The optimal concentrations of rice hulls and yeast extract, and initial pH of the medium for cell growth were 60.2 g/l, 7.38 g/l, and 7.18, respectively, whereas those for production of CMCase were 50.0 g/l, 5.00 g/l, and 7.30. The analysis of variance (ANOVA) implied that the most significant factor for cell growth as well as production of CMCase was yeast extract. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ in the medium for cell growth were 7.50, 1.00, 0.10, and 0.80 g/l, respectively, which were the same as those for production of CMCase. The optimal temperatures for cell growth and production of CMCase were 30 and $35^{\circ}C$, respectively. The maximal production of CMCase under optimized conditions was 83.8 U/ml, which was 3.3 times higher than that before optimization. In this study, rice hulls, agro-byproduct, were developed as a substrate for production of CMCase and time for production of CMCase was reduced to 3 days using a newly isolated marine bacterium.