Plant cell wall hydrolysates contain not only sugars but also substantial amounts of acetate, a fermentation inhibitor that hinders bioconversion of lignocellulose. Despite the toxic and non-consumable nature of acetate during glucose metabolism, we demonstrate that acetate can be rapidly co-consumed with xylose by engineered Saccharomyces cerevisiae. The co-consumption leads to a metabolic re-configuration that boosts the synthesis of acetyl-CoA derived bioproducts, including triacetic acid lactone (TAL) and vitamin A, in engineered strains. Notably, by co-feeding xylose and acetate, an enginered strain produces 23.91 g/L TAL with a productivity of 0.29 g/L/h in bioreactor fermentation. This strain also completely converts a hemicellulose hydrolysate of switchgrass into 3.55 g/L TAL. These findings establish a versatile strategy that not only transforms an inhibitor into a valuable substrate but also expands the capacity of acetyl-CoA supply in S. cerevisiae for efficient bioconversion of cellulosic biomass.

Plant cell wall hydrolysates contain not only sugars but also substantial amounts of acetate, a fermentation inhibitor that hinders bioconversion of lignocellulose. Despite the toxic and non-consumable nature of acetate during glucose metabolism, we demonstrate that acetate can be rapidly co-consumed with xylose by engineered Saccharomyces cerevisiae. The co-consumption leads to a metabolic re-configuration that boosts the synthesis of acetyl-CoA derived bioproducts, including triacetic acid lactone (TAL) and vitamin A, in engineered strains. Notably, by co-feeding xylose and acetate, an enginered strain produces 23.91 g/L TAL with a productivity of 0.29 g/L/h in bioreactor fermentation. This strain also completely converts a hemicellulose hydrolysate of switchgrass into 3.55 g/L TAL. These findings establish a versatile strategy that not only transforms an inhibitor into a valuable substrate but also expands the capacity of acetyl-CoA supply in S. cerevisiae for efficient bioconversion of cellulosic biomass.

Abstract Background Citrus peel waste (CPW) is a pectin‐rich agro‐industrial residue with potential as a renewable substrate for mucic acid production. However, commonly used laboratory strains of Saccharomyces cerevisiae require nutrient supplementation, which limits their industrial applicability. This study aimed to restore prototrophy, enhance fermentation performance, and optimize process conditions for efficient mucic acid production from CPW. Results Prototrophic derivatives were engineered, enabling nitrogen‐independent growth. Compared with the parental strain, the prototrophic strain achieved nearly 30% higher mucic acid titers and improved co‐utilization of D‐galacturonic acid with xylose. In simultaneous saccharification and fermentation of CPW, mucic acid production increased by 23% under nitrogen‐limited conditions. Response surface methodology identified optimal conditions of 5% CPW, 7.89 g DCW/L inoculum, 130 rpm agitation, and 48 h incubation, yielding 15.38% mucic acid, closely matching the predicted maximum. Conclusion By combining strain engineering, high‐cell‐density cultivation, and optimization, this study establishes a promising platform for the valorization of agro‐industrial residues into high‐value biochemicals, with potential benefits for cost‐effectiveness and sustainability. © 2025 Society of Chemical Industry (SCI).