Direct and Efficient Production of Ethanol from Cellulosic Material with a Yeast Strain Displaying Cellulolytic Enzymes
| Autor: | Akihiko Kondo, Shouji Takahashi, Motoo Arai, Yasushi Morikawa, Takashi Kawaguchi, Hirofumi Okada, Atsuo Tanaka, Hideki Fukuda, Mitsuyoshi Ueda, Yasuya Fujita |
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| Rok vydání: | 2002 |
| Předmět: |
Recombinant Fusion Proteins
Genetic Vectors Saccharomyces cerevisiae Cellulase Applied Microbiology and Biotechnology chemistry.chemical_compound Genes Synthetic Ethanol fuel Cellulose Chromatography High Pressure Liquid Trichoderma reesei Ethanol Ecology biology Aspergillus aculeatus Physiology and Biotechnology Enzymes Immobilized biology.organism_classification Peptide Fragments Yeast Culture Media Microscopy Fluorescence Biochemistry chemistry Fermentation biology.protein Genetic Engineering Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 68:5136-5141 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.68.10.5136-5141.2002 |
| Popis: | For direct and efficient ethanol production from cellulosic materials, we constructed a novel cellulose-degrading yeast strain by genetically codisplaying two cellulolytic enzymes on the cell surface of Saccharomyces cerevisiae . By using a cell surface engineering system based on α-agglutinin, endoglucanase II (EGII) from the filamentous fungus Trichoderma reesei QM9414 was displayed on the cell surface as a fusion protein containing an RGSHis6 (Arg-Gly-Ser-His 6 ) peptide tag in the N-terminal region. EGII activity was detected in the cell pellet fraction but not in the culture supernatant. Localization of the RGSHis6-EGII-α-agglutinin fusion protein on the cell surface was confirmed by immunofluorescence microscopy. The yeast strain displaying EGII showed significantly elevated hydrolytic activity toward barley β-glucan, a linear polysaccharide composed of an average of 1,200 glucose residues. In a further step, EGII and β-glucosidase 1 from Aspergillus aculeatus No. F-50 were codisplayed on the cell surface. The resulting yeast cells could grow in synthetic medium containing β-glucan as the sole carbon source and could directly ferment 45 g of β-glucan per liter to produce 16.5 g of ethanol per liter within about 50 h. The yield in terms of grams of ethanol produced per gram of carbohydrate utilized was 0.48 g/g, which corresponds to 93.3% of the theoretical yield. This result indicates that efficient simultaneous saccharification and fermentation of cellulose to ethanol are carried out by a recombinant yeast cells displaying cellulolytic enzymes. |
| Databáze: | OpenAIRE |
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