CITRIC-ACID PRODUCTION BY IMMOBILIZED ASPERGILLUS-NIGER IN A FLUIDIZED-BED REACTOR

Citric acid production by immobilized of Aspergillus niger in a fluidi zed bed reactor was performed, evaluating the productivity and the sta bility of the process when pulsing device was used. The application of a pulsing flow to fluidized bed reactor and the feed nitrogen limited allow to control of bioparticles morphology avoiding bed compactation . When operated at optimum pulsation frequency (0.3 s(-1)) the stabili ty of the bioreactor was maintained for more than 30 days, increasing the citric acid production in more than 52.2%.