Microbial production of Propionic and Succinic acid from Sorbitol using Propionibacterium acidipropionici

Three sequential fermentative batches were carried out with cell recycle in four simultaneously operating bioreactors maintained at pH 6.5, 30 degrees C, and 100 rpm. P. acidipropionici ATCC 4875 was able to produce propionic and succinic acid from sorbitol. The concentration of propionic acid decreased slightly from 39.5 +/- 5.2 g L-1 to 34.4 +/- 1.9 g L-1, and that of succinic acid increased significantly from 6.1 +/- 2.1 g L-1 to 14.8 +/- 0.9 g L-1 through the sequential batches. In addition, a small amount of acetic acid was produced that decreased from 3.3 +/- 0.4 g L-1 to 2.0 +/- 0.3 g L-1 through the batches. The major yield for propionic acid was 0.613 g g(-1) in the first batch and succinic acid it was 0.212 g g(-1) in the third batch. The minor yield of acetic acid was 0.029 g g(-1), in the second and third batches.