Citric acid production from pineapple waste by solid state fermentation using Aspergillus niger

Aspergillus niger metabolizes cheap carbon sources ( from wastes and by-products) in particular carbohydrate substrates such as fruit peels and pomaces. These raw materials have been used to produce citric acid in solid state fermentation by this filamentous fungi. In this paper pineapple waste is used as substrate for citric acid production by the A. niger strain ATCC 1015. The highest production (grams of citric acid per kilogram of solid waste) was obtained at 6 fermentation days, 29 degrees C, in medium containing 4% of methanol. The corresponding citric acid production was 132g/kg of the dry waste.