Ethanol production by immobilized whole cells ofZymomonas mobilis in a continuous flow expanded bed bioreactor and a continuous flow stirred tank bioreactor

Abstract

Continuous ethanol fermentation by immobilized whole cells ofZymomonas mobilis was investigated in an expanded bed bioreactor and in a continuous stirred tank reactor at glucose concentrations of 100, 150 and 200 g L⁻¹. The effect of different dilution rates on ethanol production by immobilized whole cells ofZymomonas mobilis was studied in both 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 ethanol was independent of the glucose concentration in both reactors.