METHOD FOR CITRIC ACID PRODUCTION Russian patent published in 2007 - IPC C12P7/48 C12N1/14 C12R1/685 

FIELD: microbiological industry.

SUBSTANCE: citric acid is obtained by fermentation of fungi Aspergillus niger. Fermentation is carried out in periodic mode in at least three fermenters wherein one of these fermenters is the head one, to produce in head fermenter organic acid concentration of 110-140 g/dm³ and sugar concentration of 3-5 g/dm³. and in the rest fermenters 80-90 g/dm³ and 10-12 g/dm³, respectively. Fermentation id continuous mode is carried out in two step in fermenter battery connected in parallel with the head on, wherein organic acid and sugar concentrations are maintained at 12-16 g/dm³, and viscosity is maintained at 0.04-0.05 Pa.s. In this purpose cultural liquid with sugar concentration of 3-5 g/dm³ is periodically evacuated from head fermenter and cultural liquid with sugar concentration of 10-12 g/dm³ is evacuated from the rest ones, and nutrient solution and sterile water are added thereto.. Additionally carbohydrate sources and mineral salts are introduced.

EFFECT: increased citric acid yield due to increased fermenter productivity.

2 cl, 1 tbl, 3 ex