Recovery of itaconic acid from supersaturated waste fermentation liquor

Itaconic acid (IA) is produced via fermentation from glucose which is separated from the fermentation froth by filtration, evaporation, and crystallization. This work noted that the waste liquor from crystallizer is supersaturated with residual IA that can be recovered. Change in suspension pH, temperature, or addition of activated carbon cannot destabilize the supersaturated system. However, adding small quantity of pure IA crystals recovers 22.5 g/L of IA from waste liquor. The presence of glucose enhances IA crystallization from its solution prepared with pure water. Conversely, the presence of residual glucose in the waste liquor interferes with the IA crystallization.