Cornell University, Geneva, New York 14456. Citric acid is a commercially important product that has been obtained by submerged fermentation of glucose or sucrose by Aspergillus niger. This work was undertaken to determine the potential of food processing solid residues as a substrate for citric acid production by solid state fermentation using Aspergillus niger. The results of this study indicate that food processing solid residues can serve as a low-cost substrate for citric acid production by solid state fermentation using Aspergillus niger. M. S. Islam and Rehana Begum, Division of Genetics.
Citric acid is an organic acid of diverse economic use.
The food and beverage industries use this acid extensively as a food additive. The present annual global requirement is nearly 4 lakh MTons which is produced almost entirely by fermentation of molasses sugar with selected strains of Aspergillus niger. Mutagenic techniques have been successfully employed for the improvement of Aspergillus niger strains. With the help of gamma radiations several high citric acid producing strains of Aspergillus niger were induced at our laboratory. Three of the new isolates were selected for further test under semi-pilot scale studies, Of these, mutant strain no.