Rising trend in the microbial fermentation for succinic acid production: a comprehensive overview on innovative...

Succinic acid (SA) necessitates thorough examination regarding its biological production pathway. The energy-dependent biosynthesis of SA and the resulting intracellular redox imbalance contribute to reduced SA productivity. Co-culture fermentation that combines aerobic yeast and facultative bacteria demonstrates a dual benefit for microbial growth and SA production. The optimization of the fermentation process with native SA producers resulted in higher SA titer values. The intermittent addition of bicarbonate salts increased SA production to 3.86 g L⁻¹ h⁻¹ during the anaerobic fermentation of Actinobacillus succinogenes. Fed-batch fermentation of acetic acid enhanced SA production to 12 g/L via a glyoxylate shunt in Yarrowia lipolytica. The immobilization of SA-producing microbial strains enhanced continuous fermentation, resulting in SA titers and productivity of 69 g/L and 35.6 g L⁻¹ h⁻¹, respectively. Metabolic enhancements of SA yield are increasingly documented through various rational engineering approaches applied to bacterial and yeast strains. This review paper aims to analyze the challenges associated with conventional SA fermentation processes. This work examines literature on SA production from lignocellulosic biomass, offering a comprehensive analysis of the valorization of complex biological resources. This paper emphasizes recent advancements in SA yields, reaching nearly 0.98 g SA/g substrate, attained through innovative methodologies.