Comparison of airlift and stirred reactors for fermentation with Aspergillus niger

Abstract The design and fabrication of a simple laboratory airlift fermentor are described. This reactor excels in reliability and low power requirement. Its efficiency has been proved for the production of gluconic acid by Aspergillus niger . As in the case of bubble columns, the desired morphology of A. niger, i.e pellet growth, is obtained in the laboratory airlift fermentor as well as in a pilot scale airlift fermentor of 260 l working volume. Thus, pellet formation occurred under rather low stress conditions as compared to stirred tanks where high agitation conditions are expected to be required to achieve similar results.