Engineering an efficient whole‐cell catalyst for d‐allulose production from glycerol

Abstract d ‐Allulose has many health‐benefiting properties and therefore sustainably applied in food, pharmaceutical, and nutrition industries. The aldol reaction‐based route is a very promising alternative to Izumoring strategy in d ‐allulose production. Remarkable studies reported in the past cannot get rid of by‐product formation and costly purified enzyme usage. In the present study, we explored the glycerol assimilation by modularly assembling the d ‐allulose synthetic cascade in Escherichia coli envelop. We achieved an efficient whole‐cell catalyst that produces only d ‐allulose from cheap glycerol feedstock, eliminating the involvement of purified enzymes. Detailed process optimization improved the d ‐allulose titer by 1500.00%. Finally, the production was validated in 3‐L scale using a 5‐L fermenter, and 5.67 g L −1 d ‐allulose was produced with a molar yield of 31.43%.