Integrating Green Process Engineering With Whole-Cell Catalysis to Intensify Sustainable Glucaric Acid Production.

This study pioneered a whole-cell biocatalytic process using engineered Gluconobacter oxydans to produce glucaric acid (GA), a food additive, from glucuronic acid (GlcA). From a molecular perspective, molecular dynamics simulations have confirmed that van der Waals forces and hydrogen bond interactions in acidic environments effectively stabilized the structure-activity relationship of dehydrogenase and GlcA. Leveraging this insight, multi-strategies were implemented, including pH regulation, high-density biocatalysis, dehydrogenase overexpression, adaptive acclimation, bioreactor scale-up, and cell recycling technology, to significantly intensify the GA production. As a result, the recombinant G. oxydans achieved an effective production of 10.27 g/L GA with a productivity of 0.21 g/L/h, representing a 366.4% intensification over the unregulated system. In comparison with the highest level of biological methods reported to date, the process demonstrates greater economic feasibility and industrial application potential. This work elucidated the molecular mechanism of acid-intensified biocatalysis and provided a sustainable, industrially viable GA production platform.