Production of citric acid – a short review

Citric acid is widely used as a flavouring agent in a long list of preparations. It is one of the few organic acids found in limes and lemons in particularly high concentrations. It can be produced by biotechnological fermentation with the help of fungal species like Aspergillus niger. There have been various attempts to produce citric acid efficiently from inexpensive raw materials. This review is an attempt to describe the various organisms and substrates utilized for the production of citric acid over a period of past 10 years.