• Journal of Microbiology and Biotechnology
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• 제24권4호
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• pp.440-446
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• 2014

The carbohydrate-binding module (CBM) is an important domain of most cellulases that plays a key role in the hydrolysis of cellulose. The neutral endoglucanase (EG1) gene was reconstructed. A redesigned endoglucanase, named EG2, was constructed with a CBM containing a linker from Corticium rolfsii (GenBank Accession No. D49448). The redesigned EG genes were expressed in Escherichia coli, and their characteristics are discussed. Results showed that the degradation of cellulose by EG2 was about double that by EG1. The specific activities of EG1 and EG2 were tested under optimal conditions, and EG2 had higher activity ($169.1{\pm}2.74$ U/mg) toward CMC-Na than did EG1 ($84.0{\pm}1.98$) in the process of cellulose degradation. The optimal pH and temperature, pH stability, and heat stability of EG1 and EG2 were similar. Results indicated that the CBM plays an essential role in the hydrolysis of cellulose. We can improve EG's catalytic power by adding the CBM from Corticium rolfsii.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권1호
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• pp.44-47
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• 1998

Maximum cellulase production was sought by comparing the activities of the cellulases produced by different Trichoderma reesei strains and Aspergillus niger. Trichoderma reesei Rut-C30 showed higher cellulase activity than other Trichoderma reesei stains and Aspergillus niger that was isolated from soil. By optimizing the cultivation conditions during shake flask culture, higher cellulase production could be achieved. The FP(filter paper) activity of 3.7U/ml and CMCase (Carboxymethylcellulase) activity of 60U/ml were obtained from shake flask culture. When it was grown in 2.5L fermentor, where pH and DO levels are controlled, the enzyme activities were 133.35U/ml (CMCase) and 11.67U/ml(FP), respectively. Ammonium sulfate precipitation method was used to recover enzymes from fermentation broth. The dried cellulase powder showed 3074.9U/g of CMCase activity and 166.7U/g of FP activity with 83.5% CMCase recovery.

• Mycobiology
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• 제45권4호
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• pp.370-378
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• 2017

Cylindrocarpon destructans is an ascomycete soil-borne pathogen that causes ginseng root rot. To identify effective biocontrol agents, we isolated several bacteria from ginseng cultivation soil and evaluated their antifungal activity. Among the isolated bacteria, one isolate (named JH7) was selected for its high antibiotic activity and was further examined for antagonism against fungal pathogens. Strain JH7 was identified as a Chromobacterium sp. using phylogenetic analysis based on 16S rRNA gene sequences. This strain was shown to produce antimicrobial molecules, including chitinases and proteases, but not cellulases. Additionally, the ability of JH7 to produce siderophore and solubilize insoluble phosphate supports its antagonistic and beneficial traits for plant growth. The JH7 strain suppressed the conidiation, conidial germination, and chlamydospore formation of C. destructans. Furthermore, the JH7 strain inhibited other plant pathogenic fungi. Thus, it provides a basis for developing a biocontrol agent for ginseng cultivation.

• 한국식품조리과학회지
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• 제21권6호통권90호
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• pp.776-781
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• 2005

Preparation of nectar using Kabocha squash was optimized and the quality changes during 7 weeks'storage were investigated. The paste for the nectar base could be effectively obtained by consecutive processes of steaming for 15 min, crude smashing and homogenization. To improve the mouth-feel of the nectar, various pectinases and cellulases were treated with Econase CE, Rapidase press, Macerozyme A, Sumizyme MC and Cytolase M102. Among them, Cytolase M102 was the most effective enzyme at $0.05\%$ for 90 min reaction in terms of the collective results as the residue of the nonsoluble solids, viscosity and alcohol test. The best ratio of the nectar ingredients was a ratio of water to paste of 1.5, $11^{o}$Brix of saccharinity, $0.025\%$ of citric acid and $0.15\%$ of xanthan gum. When the retort sterilized nectar in a can was stored in an incubator at $35^{\circ}C$ for 7 weeks, the color, pH, saccharinity, viscosity and total count plates remained almost unchanged.

• 환경생물
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• 제35권4호
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• pp.648-653
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• 2017

The aim of this study was to select various fungal strains indigenous to Korea that have the potential to produce cellulases, including filter paper activity (FPase), $endo-{\beta}$-1,4-glucanase (EG), and ${\beta}-glucosidase$ (BGL). Among the 25 species of Ascomycetes and the 32 species of Basidiomycetes tested in this study, the Bjerkandera adusta KUC10565, Heterobasidion orientale KUC10556, Hyphoderma praetermissum KUC10609, and Trichoderma harzianum KUC1716 all exhibited remarkably high FPase activity. In addition, the T. harzianum KUC1716 showed high levels of EG and BGL activity. This strain has been selected for further study because of their enzymatic potential.

• 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.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.740-746
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• 2021

Efficient cellulolytic enzyme production is important for the development of lignocellulose-degrading enzyme mixtures. However, purification of cellulases from their native hosts is time- and labor-consuming. In this study, a constitutive expression system was developed in Penicillium oxalicum for the secreted production of proteins. Using a constitutive polyubiquitin gene promoter and cultivating with glucose as the sole carbon source, nine cellulolytic enzymes of different origins with relatively high purity were produced within 48 h. When supplemented to a commercial cellulase preparation, cellobiohydrolase I from P. funiculosum and cellobiohydrolase II from Talaromyces verruculosus showed remarkable enhancing effects on the hydrolysis of steam-exploded corn stover. Additionally, a synergistic effect was observed for these two cellobiohydrolases during the hydrolysis. Taken together, the constitutive expression system provides a convenient tool for the production of cellulolytic enzymes, which is expected to be useful in the development of highly efficient lignocellulose-degrading enzyme mixtures.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.

• KSBB Journal
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• 제11권3호
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• pp.317-322
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• 1996

식품 및 화장품의 첨가제로 사용되는 기능성 올리고당인 갈락토올리고당을 생룰로스 가수분해 효소를 이용하여 생산하였다. 여섯가지의 효소 시료 가운데, P Penicillium funiculosum에서 유래한 셀룰로스 가수 분해 효소가 가장 높은 올리고당 생산 수율을 보였다. 올리고당 생산을 위한 최적온도와 pH는 각각 $50^{\circ}C$,와 5.0이었으며 유당농도와 효소농도사at의 최 적비는 lO(w/w) 이었다. 시간에 따른 올리고당 생산 반응의 경향성은 유당분해 효소 반응과 유사하였 으며 초기 유당농도가 증가함에 따라 생성되는 올리 고당의 농도가 증가하였다. 최척반응조건에서 20% (w/v)의 유당으로 부터 최고 23%(w/w)의 올리고 땅을 얻을 수 있었다. 생성된 올라고당의 성분은 고 속액체 크로마토그래프와 박층 크로마토그래프 분석 을 통하여 삼당과 사당으로 이루어져 있음을 확인하였다.

• 한국균학회지
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• 제25권1호통권80호
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• pp.68-76
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• 1997

섬유소자원의 이용을 목적으로 담자균류인 T. trogii를 실험 균주로 하여 합성배지에서 cellulase 생성 최적 배양조건을 검토해 본 결과는 다음과 같다. 합성배지에서 T. trogii에 의한 cellulase 생산은 $30{\sim}35^{\circ}C,\;pH\;4.0{\sim}6.0,\;and\;11{\sim}15$일 배양시 가장 높았다. 탄소원은 Avicelase와 ${\beta}-glucosidase$의 경우 CMC를, CMCase는 cellulose를 탄소원으로 했을 때 최고의 생산성을 보였으며, CMC의 최적 농도는 세 효소 모두 3%이었다. 질소원은 ammonium tartrate 첨가시 cellulase 생산이 높았으며, 그 최적 농도로 Avicelase와 ${\beta}-glucosidase$는 0.03N, CMCase는 0.04 N이었다.