Effect of carbon pulsing on the redox household of Lactobacillus diolivorans in order to enhance 1,3-propanediol production

- Glucose pulsing as a key factor for enhanced 1,3-propanediol formation.
- Improved ratio of 1,3-propanediol to 3-hydroxypropionic acid formation of 45:1.
- Significant reduction of 3-hydroxypropionic acid formation down to 1.7 g/L.
- Production of up to 92 g/L 1,3-PDO with a maximum productivity of 1.74 g/Lh.

This study investigates potential limitations of 1,3-propanediol formation by Lactobacillus diolivorans. Particular focus is given to enhanced glycerol utilization as well as the elimination of by-product formation. The key aspect is a modulation of the redox household by process engineering through the application of carbon pulses. A shift in the product pattern of C3 products was achieved, improving the ratio of 1,3-propanediol versus 3-hydroxypropionic acid up to a level of 20:1. Moreover, in combination with alternative feeding strategies this ratio was enhanced up to 45:1 and the maximum observed productivity of 1,3-propanediol could be significantly increased to 1.7 g/Lh.