Effect of Additional Mineral Ions on Citric Acid Productivity by Aspergillus Niger Ng-110

The mutant strain of Aspergillus niger NG-110 was evaluated for the present investigation of citric acid production. The cultural conditions optimized during the course of study were pH and K4Fe(CN)6, K2HPO4 and CaCl2 concentrations. Cane-molasses was utilized as the basal fermentation medium. The mutant NG-110 produces maximal amount of citric acid when the pH of the medium was 6. When the concentrations of K4Fe(CN)6, K2HPO4 and CaCl2 were 200 ppm, 0.2% w/v and 2.0%, the maximum citric acid production was 69.30±0.8 g/l, 81.21±0.2 g/l and 80.76±0.2 g/l, respectively.