High-yield production of citric acid by Yarrowia lipolytica on glycerol in repeated-batch bioreactors.

An acetate negative mutant of Yarrowia lipolytica Wratislavia AWG7 was found to be suitable for the production of high amounts of citric acid in long-term repeated-batch cultures. When 40% of fresh replaced medium was fed, this strain produced 154 g l(-1), on average, which corresponded to a 0.78 g g(-1) yield and a productivity of 1.05 g l(-1) h(-1). The activity of the culture remained stable for more than 1,650 h, i.e., 16 cycles of the repeated-batch bioreactors.