ETHANOL-PRODUCTION BY IMMOBILIZED WHOLE CELLS OF ZYMOMONAS-MOBILIS INA CONTINUOUS-FLOW EXPANDED BED BIOREACTOR AND A CONTINUOUS-FLOW STIRRED-TANK BIOREACTOR

Continuous ethanol fermentation by immobilized whole cells of Zymomona s mobilis was investigated in an expanded bed bioreactor and in a cont inuous stirred tank reactor at glucose concentrations of 100, 150 and 200 g L(-1). The effect of different dilution rates on ethanol product ion by immobilized whole cells of Zymomonas mobilis was studied in bot h reactors. The maximum ethanol productivity attained was 21 g L(-1) h (-1) at a dilution rate of 0.36 h(-1) with 150 g glucose L(-1) in the continuous expanded bed bioreactor. The conversion of glucose to ethan ol was independent of the glucose concentration in both reactors.