ETHANOL PRODUCTION FROM STARCH BY CO-IMMOBILIZED AMYLOGLUCOSIDASE - ZYMOMONAS MOBILIS CELLS IN A CONTINUOUSLY-STIRRED BIOREACTOR

摘要

Continuous ethanol production from starch was studied in a continuously-stirred bioreactor using co-immobilized amyloglucosidase (AMG) and Zymomonas mobilis cells. In this process, saccharification of starch and fermentation to ethanol were carried out in a single reactor The experiments were carried out at three sets of conditions for which temperature and centrifuged cell weight were 35 degrees C and 20.3 g; 30 degrees C and 19.0 g; 35 degrees C and 29.2 g, respectively. The maximum volumetric ethanol productivity (7.6 g.L-1.h(-1)) was achieved with 0.45 g.g(-1) yield at the 0.20 h(-1) dilution rate at 35 degrees C, with the initial centrifuged cell concentration of 29.2 g. The maximum ethanol concentration (43.5 g.L-1) was obtained at the 0.15 h(-1) dilution rate with a 96 % conversion of substrate. When experimental conditions in the reactor were compared to each other, the initial concentration of immobilized cells was found to have a significant positive influence on the kinetic parameters of ethanol fermentation. Biotechnol. & Biotechnol. Eq. 2013, 27(1), 3506-3512