2,5-Diketo-gluconic acid reductase from Corynebacterium glutamicum: Characterization of stability, catalytic properties and inhibition mechanism for use in vitamin C synthesis

► 2,5-Diketo-gluconic acid (2,5-DKG) reductase activity was found in 9 bacterial strains. ► 2,5-DKG reductase synthesizes the immediate precursor of vitamin C. ► Corynebacterium glutamicum 2,5-DKG reductase was expressed in high yield and characterized. ► The catalytic mechanism and inhibition kinetics were elucidated to guide enzyme and process engineering.