Cellulases without carbohydrate-binding modules in high consistency ethanol production process
| Autor: | Terhi Puranen, Demi T. Djajadi, Anikó Várnai, Liisa Viikari, Annukka Pakarinen, Mai Østergaard Haven |
|---|---|
| Přispěvatelé: | Department of Food and Nutrition |
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
CBM
DOMAINS ADSORPTION education INHIBITION Cellulase Management Monitoring Policy and Law Applied Microbiology and Biotechnology chemistry.chemical_compound Hydrolysis Recyclability SOLIDS ENZYMATIC-HYDROLYSIS Cellulases CELLOBIOHYDROLASE-I Ethanol fuel CRYSTALLINE CELLULOSE TEMPERATURE Trichoderma reesei High consistency 219 Environmental biotechnology chemistry.chemical_classification Ethanol biology Renewable Energy Sustainability and the Environment Chemistry Research Substrate (chemistry) LIMITED PROTEOLYSIS biology.organism_classification Complementation TRICHODERMA-REESEI General Energy Enzyme Biochemistry Cellobiohydrolases biology.protein 1182 Biochemistry cell and molecular biology Carbohydrate-binding modules Lignocellulose Biotechnology |
| Zdroj: | Biotechnology for Biofuels |
| Popis: | Background Enzymes still comprise a major part of ethanol production costs from lignocellulose raw materials. Irreversible binding of enzymes to the residual substrate prevents their reuse and no efficient methods for recycling of enzymes have so far been presented. Cellulases without a carbohydrate-binding module (CBM) have been found to act efficiently at high substrate consistencies and to remain non-bound after the hydrolysis. Results High hydrolysis yields could be obtained with thermostable enzymes of Thermoascus aurantiacus containing only two main cellulases: cellobiohydrolase I (CBH I), Cel7A and endoglucanase II (EG II), Cel5A. The yields were decreased by only about 10% when using these cellulases without CBM. A major part of enzymes lacking CBM was non-bound during the most active stage of hydrolysis and in spite of this, produced high sugar yields. Complementation of the two cellulases lacking CBM with CBH II (CtCel6A) improved the hydrolysis. Cellulases without CBM were more sensitive during exposure to high ethanol concentration than the enzymes containing CBM. Enzymes lacking CBM could be efficiently reused leading to a sugar yield of 90% of that with fresh enzymes. The applicability of cellulases without CBM was confirmed under industrial ethanol production conditions at high (25% dry matter (DM)) consistency. Conclusions The results clearly show that cellulases without CBM can be successfully used in the hydrolysis of lignocellulose at high consistency, and that this approach could provide new means for better recyclability of enzymes. This paper provides new insight into the efficient action of CBM-lacking cellulases. The relationship of binding and action of cellulases without CBM at high DM consistency should, however, be studied in more detail. |
| Databáze: | OpenAIRE |
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