Co-immobilized aerobic/anaerobic mixed cultures in stirred tank and gaslift loop reactors

Co-immobilized Aspergillus awamori and Zymomonas mobilis cultures were investigated in a stirred tank reactor on synthetic medium with starch as substrate at various dissolved oxygen concentrations. In a gaslift loop reactor, freely suspended and immobilized A. awamori were cultivated on synthetic medium and soluble potato starch. In the same reactor, the growth and ethanol production of freely suspended and immobilized Z. mobilis cultures were studied on synthetic medium and glucose. Co-immobilized A. awamori and Z. mobilis were cultivated in batch and continuous operations in the gaslift loop reactor on synthetic medium with starch substrate at different dissolved oxygen concentrations. The interrelations between the different process variables are discussed.