CitricAcid Production from Carob Pod Extract by Aspergillus. Niger

Abstract

The present study was undertaken to study the production of citric acid by the fungus Aspergillus niger using carob pod extract as a carbon source for fungal growth and production of citric acid. High yields of citric acid were achieved after six days of incubation when 10% of carob pod extract as a carbon source present in fermentation media with pH value of 3.16 and the amount of yield being12.25g\l, (55.48%). The results also revealed that the accumulation of citric acid by the fungus was affected by the source and concentration of nitrogen, as well as high production of the acid was obtained in fermentation medium containing ammonium sulphate, in which the accumulated amount increased up to 18.25g\l, (70.16%). Moreover, the addition of 0.05% calcium chloride and 2% ethanol to the fermentation medium highly stimulated citric acid accumulation by the fungus to reach 21.06g\l and this amount equivalent to 113.22% of the biomass dry weight.