Metabolic engineering has shown that optimizing metabolic pathways’ fluxes for industrial
purposes requires a methodical approach. Accordingly, in this study, in silico metabolic
modeling was utilized to characterize the lesser-known strain Basfia succiniciproducens
under different environmental conditions, followed by the use of industrially relevant
substrates for succinic acid synthesis. Based on RT-qPCR carried out in flask experiments,
we discovered a relatively large difference in the expression levels of ldhA gene
compared to glucose in both xylose and glycerol cultures. In bioreactor-scale fermentations,
the impact of different gas phases (CO 2 , CO 2 /AIR) on biomass yield, substrate
consumption, and metabolite profiles was also investigated. In the case of glycerol,
the addition of CO 2 increased biomass as well as target product formation, while
using CO 2 /AIR gas phase resulted in higher target product yield (0.184 mM⋅mM −1
). In case of xylose, using CO 2 alone would result in higher succinic acid production
(0.277 mM⋅mM −1 ). The promising rumen bacteria, B. succiniciproducens , has shown
to be suitable for succinic acid production from both xylose and glycerol. As a result,
our findings present new opportunities for broadening the range of raw materials used
in this significant biochemical process. Our study also sheds light on fermentation
parameter optimization for this strain, namely that, CO 2 /AIR supply has a positive
effect on target product formation.
