Aerobic fungal cell immobilization in a dual hollow-fiber bioreactor: Continuous production of a citric acid.

摘要: Aspergillus niger B60 was immobilized in a dual hollow-fiber bioreactor (DHFBR) to produce citric acid continuously. The fungi proliferated well the interstitial region formed by parallel arrangement of three microporous polypropylene hollow fibers contained within silicone tube. Long-term operation with nitrogen-enriched medium not possible due expansion tubes continual cell growth. fungal growth could be controlled supplying nitrogen-deficient at production stage. With pure oxygen aeration and medium, volumetric productivity reached 1.62 g/L h residence time 4.02 h, which corresponded 27-fold increase over that shake-flask fermentation. When increased 20.1 concentration 26 continuously produced, yield 80-90% 1.3 h. This represents significant improvement final concentration, yield, equivalent values corresponding batch fermentation, were 18 g/L, 40%, 0.06 respectively.