Effect of the Composition of the Sporulation Medium on Citric Acid Production by Aspergillus niger in Submerged Culture

Abstract

The presence of Mn and malt extract in the sporulation medium at a level of 9.3 mg. and 1.5 g., respectively, to 1 liter accelerated spore formation and reduced the acid production in submerged fermentation. The harmful effect of the presence of Mn in sporulation medium to the acid production is attributed to the amt. of Mn carried over by washed spore inoculum into the fermentation. The Mn carried over with the spore inoculum at a level of 3 [gamma] per liter of fermentation medium appreciably lowered the citric acid yield. The presence of KH2PO4, NH4NO3 and Zn at high concs. retarded spore formation.