Bio-succinic acid production, up to pilot scale, by fermentation of industrial candy waste with Actinobacillus succinogenes 130Z and its downstream purification process

Nowadays, the global community faces a worldwide challenge concerning the minimization of carbon emissions. Significant efforts are being conducted to apply environmental-friendly processes, such as the production of succinic acid by utilizing waste residual streams through a biorefinery approach. In this context, this study aimed to upscale the fermentative production (batch mode) of succinic acid (SA) by Actinobacillus succinogenes 130Z from an industrial candy residue. Process performance (titer, productivity, yield) was assessed at different operating conditions such as CO₂ headspace gas overpressure (0, 0.4, 1.0, and 1.4 atm), initial sugars concentration (about 70, 95, 117 g L⁻¹), yeast (10, 15 g L⁻¹) and MgCO₃ (0, 10 g L⁻¹) concentration in fermentation media using two different batches of an industrial candy residue batches. SA concentration varied in the range of 37.78 ± 0.02–39.94 ± 0.04 g L⁻¹ both in lab and pilot trials with yields of up to 0.74 (g g⁻¹). Finally, a successful downstream concept for SA purification (pre-purification, membrane filtration, ion-exchange, vacuum distillation, and crystallization) was investigated. High purity (up to 93.5 ± 1.8 %) and SA crystallization recovery (up to 86.7 ± 3.2 %) was achieved from the fermentation broths.