Novel multienzyme cascade for efficient synthesis of d-allulose from inexpensive sucrose

d-Allulose is one of the most common rare sugars with low calorie and is extensively applied in the food, cosmetic, and pharmaceutical fields. Here, a novel in vitro multienzyme cascade route (MCAS) was designed to produce d-allulose from sucrose. The MCAS route comprised three modules (sucrose phosphorolysis, phosphorylation–dephosphorylation, and ATP regeneration), including five enzymes (sucrose phosphorylase, fructokinase, d-allulose 6-phosphate 3-epimerase, d-allulose 6-phosphatephosphatase, and polyphosphate kinase). As a rate-limiting enzyme, d-allulose 6-phosphate 3-epimerase from Pantoea sp. was semi-rationally engineered, and variant Y143F led to 88.8% yield of d-allulose from 10 mM sucrose using one-pot strategy. ATP consumption was reduced to 5% of the sucrose concentration after introducing ATP-regeneration system. At elevated sucrose concentration of 100 mM by two-step strategy, a d-allulose yield of 70.4% was achieved with a space-time yield of 1.06 g L−1·h−1. This study provides an efficient and cost-effective approach for producing d-allulose from sucrose.