Citric acid production by Aspergillus niger immobilized on cellulose microfilbrils: influence of morphology and fermenter conditions on productivity

摘要

Continuous and batch production of citric acid form sucrose has been investigated using Aspergillus niger NCIM 588. Mycelia of A. Niger grown on cellulose microfilbril forms a uniform and thin mycelial proliferation under controlled conditions of cultivation rich in oxygen. In the fed batch mode using a recycle reactor, the DO of the system was maintained at 20 mg l~01 using oxygen enriched air. This improved volumetric productivity to 1.85 g l~-1 h~-1 of citric acid, representing an increase of at least 15-fold over results obtained simultaneously using shake-flasks and 1.6-fold over a conventional aerated batch reactor.