Production of fumaric acid by immobilized Rhizopus arrhizus on net

An immobilization method using net was developed for fumaric acid fermentation by Rhizopus arrhizus RH-07-13. The large surface of the net immobilized enough filamentous mycelia which produced fumaric acid rapidly. Net size and spore concentration were optimized to enhance fermentation performance and 150 cm2 of net size, 0.5 × 106 per ml of spore concentration were selected finally. Compared to free-cell fermentation, fumaric acid production was flat (32.03 vs. 31.23 g/L) but fermentation time reduced 83.3% (24 vs. 144 h).