Ethanol Production in Fixed-Film Bioreactors Employing Zymomonas Mobilis
Columnar reactors containing immobilized cells of Zymomonas mobitis were employed for the continuous production of ethanol from glucose. Two different immobilization strategies were employed in these investigations. In one case, cells were immobilized via flocculation, while in the other cells became entrapped in borosilicate glass fiber pads. The reactors were operated both in the fixedbed and expanded-bed manner. Maximum ethanol productivities of 132.0 and 85.5 g of ethanol produced per ℓ of reactor volume•h were observed in the flocculant and fiber entrapped bioreactors, respectively. Data obtained from studies employing 5.0 and 10.0% (w/v) glucose concentrations will be presented, and problems encountered during the operation of the continuous, immobilized cell bioreactors will be discussed.