Impact of nitrogen deficiency on succinic acid production by engineered strains of Yarrowia lipolytica.

Yarrowia lipolytica strains PGC01003 and PGC202 engineered for succinic acid production were studied and compared to the wild type strain W29. For the first time, these two strains were characterized in a chemically defined medium. Strain growth and organic acid production were investigated in fed-batch mode with glycerol as carbon and energy source. This study evaluated the impact of nitrogen deficiency strategy to redirect carbon flux toward succinic acid synthesis. Strain PGC01003 produced 19 g L-1 succinic acid with an overall yield of 0.23 g g-1 and an overall productivity of 0.23 g L-1 h-1, while strain PGC202 produced 33 g L-1 succinic acid with an overall yield of 0.12 g g-1 and a productivity of 0.57 g L-1 h-1. Nitrogen limitation effectively stopped biomass growth and increased succinic acid yield of PGC01003 and PGC202 by 18 % and 62 %, respectively. However, the specific succinic acid production rate was reduced by 77 % and 66 %, respectively.