FUMARIC-ACID PRODUCTION BY RHIZOPUS-ARRHIZUS IMMOBILIZED IN DIFFERENT CARRIERS

Rhizopus arrhizus NRRL 1526 immobilized in Ca-alginate produced in batch process (5 days) higher yields of fumaric acid than cultures in which the fungus was immobilized in agar or adsorbed on polyurethane foam, perlite or alumina. The entrapped mycelium showed good producing capacity with no apparent loss of activity in five successive batches (5 days each). Scanning electron microscopy revealed that the mycelial growth was essentially confined to the bead surface; clear signs of abrasion, probably caused by the strong medium agitation and the presence of Ca-carbonate were also detected.