Abstract
A number of reports have been published on the production of citric acid by sub-merged mold culture. Most of them, however, have laid stresses on the effects of chemi-cal factors, such as metal ions, nitrogen sources, potassium ferrocyanide and methanol, and very little has been reported on the effect of other factors.
The form of mycelia of mold changes depending on the physical characters cf broth, and it was found that Aspergillus niger 93A, which showed a constant activity of citric acid production, could increase its acid production activity when mycelial forms were controlled to filamentous by adding suitable non-ionic surface active agents to the broth.
