Production of Bioethanol from Spent Grain�A By-Product of Beer
Production
MBAA TQ vol. 43, no. 3, 2006, pp.
189-193 |
VIEW ARTICLE
Sho Shindo and Tadanori Tachibana. Akita Research Institute of Food and
Brewing, Akita, Japan.
Abstract
Bioethanol production from spent grain using immobilized yeast cells was
investigated. Spent grain was liquefied by steam explosion treatment to obtain
liquefied sugar. Bioethanol production was carried out by immobilized
Saccharomyces cerevisiae and Yamadazyma stipitis acting together on
the liquefied spent grain. Both yeast species were immobilized on a glass bead
carrier. When repeated batch bioethanol production from liquefied spent grain
with coimmobilized yeast cells was carried out, the productivity of bioethanol
was maintained at a high level over a period of 20 days. The bioethanol yield (Ye/s
ethanol yield [g of ethanol per g of sugars]) of our coimmobilized fermentation
system was 0.28 g/g, and was comparable to the yield of a free yeast
cofermentation system, which was 1.7 times higher.
Keywords: bioethanol,
immobilized yeast cells, spent grain
S�ntesis
Se estudi� la posibilidad de producir bioetanol de afrecho (dreche)
utilizando c�lulas de levadura inmovilizadas. Se licuific� el afrecho mediante
la explosi�n de vapor para obtener az�car l�quido. Se produjo bioetanol con la
acci�n combinada de c�lulas inmovilizadas (sobre un soporte de esferas de
vidrio) de Saccharomyces cerevisiae y Yamadazyma stipitis sobre
este afrecho licuificado. La producci�n de lotes continuos repetidos de
bioetanol con este proceso se pudo mantener a un alto nivel a lo largo de 20
d�as. El rendimiento de bioetanol de este sistema de fermentaci�n coinmovilizada
fue de 0,28 g de etanol/g de az�car, comparable con el rendimiento de un sistema
de cofermentaci�n con levadura libre, que fue 1,7 veces mayor.
Palabras claves:
bioetanol, c�lulas de levadura inmovilizadas c�lulas de levadura, afrecho
(dreche)
