PERFORMANCE OF COIMMOBILIZED YEAST AND AMYLOGLUCOSIDASE IN A FLUIDIZED-BED REACTOR FOR FUEL ETHANOL-PRODUCTION

The performance of coimmobilized Saccharomyces cerevisiae and amyloglu cosidase (AG) was evaluated in a fluidized-bed reactor. Soluble starch and yeast extracts were used as feed stocks. Conversion of soluble st arch streams to ethanol has potential practical applications in corn d ry and wet milling and in developmental lignocellulosic processes. The bio-catalyst performed well, and demonstrated no significant loss of activity or physical integrity during 10 wk of continuous operation. T he reactor was easily operated and required no pH control. No operatio nal problems were encountered from bacterial contaminants even though the reactor was operated under nonsterile conditions over the entire c ourse of experiments. Productivities ranged between 25 and 44 g ethano l/L/h/. The experiments demonstrated that ethanol inhibition and bed l oading had significant effects on reactor performance.