Question

Factors affecting citric acid production

Answer 1

The conditions for citric acid fermentation were established during the '30s and '40s when the effects of various components of the fermentation media were evaluated.

The accumulation of citric acid is strongly influenced by the composition of the medium, especially in submerged fermentation processes. However, with the exception of early studies by Currie (15), there were no other systematic studies on the composition of the medium until the 40s (92, 93). These authors developed a medium that was the basis for further research on the production of citric acid. It was shown that the factors mainly affecting the citric fermentation are the type and concentration of carbon source, nitrogen and phosphate limitation, pH, aeration, oligoelements concentration, and morphology of the producing microorganism. Certain nutrients have to be in excess (such as sugars, protons or oxygen), other at limiting levels (such as nitrogen and phosphate) and others below well-established threshold values (such as trace metals, particularly manganese).