Citric acid production from whey with sugars and additives by Aspergillus niger

Abstract

Citric acid (CA) production by Aspergillus niger ATCC9642 from whey with different concentrations of 
sucrose, glucose, fructose, galactose riboflavin, tricalcium phosphate and methanol in surface culture 
process was studied. It was found that whey with 15% (w/v) sucrose with or without 1% methanol was 
the most favourable medium producing the highest amount (106.5 g/l) of citric acid. Lower CA was 
produced from whey with other concentrations of sugars and other additives used. Highest biomass of 
A. niger was produced with the addition of riboflavins. In general, extension of the fermentation (up to 
20 days) resulted in an increase in CA and biomass, and decrease in both residual sucrose and pH 
values.