Abstract
We aimed to produce ethanol efficiently by enzymatic saccharification coupled with ethanol fermentation using wheat bran as a biomass. For this purpose, we examined pretreatment conditions of biomass and a combination of commercially available enzyme products for saccharification. When a 3.3% (w/v) wheat bran suspension was pretreated using subcritical water at 140°C with a holding time of 0 h, followed by saccharification at 45°C using a mixture of commercially available Meiselase (composed of cellulase, ce!lobiase/β?- glucosidase, and xylanase) and Novozyme*188 (composed of cellobiase/βS-glucosidase,« amylase, and glucoamylase) at a ratio of 4 to 1 by weight, glucose was released at 10.6 g/l, which corresponded to 90% of the value calculated on the basis of the total amount of glucose-based saccharides contained in the wheat bran. On the other hand, from a pretreated 33% (w/v) wheat bran suspension, 85 g/l glucose was produced, which corresponded to only 72% of the theoretical value, owing to the inhibitory effect of glucose on β?-glucosidase activity. However, when fermentation was carried out at 30°C following 24-h saccharification of the pretreated wheat bran using a mixture of Meiselase and Novozyme*188, the inhibitory effect of glucose was considered to be reduced and as a result, after 21-h fermentation, ethanol was produced at 5.2% (w/v), which corresponded to 88% of the theoretical maximum value.
Original language | English |
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Pages (from-to) | 216-223 |
Number of pages | 8 |
Journal | Seibutsu-kogaku Kaishi |
Volume | 87 |
Issue number | 5 |
Publication status | Published - Jul 27 2009 |
Keywords
- Bioethanol
- Enzymatic saccharification
- Ethanol fermentation
- Wheat bran subcritical water treatment
ASJC Scopus subject areas
- Biotechnology
- Food Science
- Applied Microbiology and Biotechnology