Abstract
Succinic acid has been considered an important molecule in the transition of chemical manufacturing from fossil-based to sustainable and future-proof processes. While there has been extensive research on biotechnological succinic acid production from biomass, attempts to roll out bio-succinic acid are impeded by its high price and remaining sustainability issues. Both drawbacks are interconnected and can be traced back to the used feedstocks and a wasteful expenditure of acid and base, among others. In this opinion, we discuss biochemical principles and metabolic pathways of next-generation carbon assimilation and low-pH fermentations to address these drawbacks. For this reason, we chart the potential for producing succinic acid from sustainable next-generation feedstocks based on electron, carbon and ATP balances as well as relevant thermodynamic considerations. Furthermore, we summarize key advances in low-pH succinic acid synthesis using acid-tolerant yeasts and assess the suitability of selected acid tolerance mechanisms for industrial application. Eventually, we aim to inspire researchers to synthesize innovative approaches to realize competitive and sustainable biotechnological succinic acid production.