Biosuccinic acid production from potato peel waste by fermentative strategies. Process enhancement

Food waste valorization is a critical strategy to accomplish environmental objectives and achieve the United Nations Sustainable Development Goals. This study focuses on the employment of potato peel waste (PPW), an abundant and renewable byproduct from the potato processing industry, as feedstock for the fermentative production of succinic acid (SA), a versatile bio-based platform chemical. Two fermentation strategies - Sequential Hydrolysis and Fermentation (SHF) and Pre-Saccharification and Simultaneous Saccharification and Fermentation (PSSF) – were implemented employing the bacteria Actinobacillus succinogenes. Key parameters, including liquid-to-solid ratio (LSR), nutrient supplementation, and magnesium carbonate levels, were evaluated in flask experiments. Optimal results were obtained with PSSF methodology at an LSR of 10 g/g without nutrient supplementation, achieving a SA yield of 0.94 g SA/g glucose consumed, with a concentration of 45.91 g/L and a productivity of 0.65 g/L h. The scalability of the process was confirmed in a bioreactor, reaching SA concentrations, yields and productivities of 42.51 ± 1.81 g/L, 0.89 g SA/g glucose consumed and 0.89 g/L h, respectively. Notably, operating at a pH of 6.8 without the addition of magnesium carbonate, simplified the process and reduced costs without compromising productivity. These findings underscore the potential of PPW as a sustainable feedstock for SA production, aligning with circular economy initiatives by transforming agricultural waste into high-value chemicals. This approach supports the development of competitive and environmentally friendly biorefineries. • Potato peel waste is valorized as a feedstock for succinic acid production . • PSSF scheme outperforms SHF in SA efficiency in flasks experiments . • PSSF scheme report optimal results of 45.91 g SA/L and 0.94 g SA/ g glucose . • Bioreactor scale-up confirms scalability with results of 42.51 g/L and 0.89 g/L h . • Exclusion of MgCO 3 simplifies the process and reduces production costs.