The Engineering, Expression, and Immobilization of Epimerases for D-allulose Production

The rare sugar D-allulose is a potential replacement for sucrose with a wide range of health benefits. Conventional production involves the employment of the Izumoring strategy, which utilises D-allulose 3-epimerase (DAEase) or D-psicose 3-epimerase (DPEase) to convert D-fructose into D-allulose. Additionally, the process can also utilise D-tagatose 3-epimerase (DTEase). However, the process is not efficient due to the poor thermotolerance of the enzymes and low conversion rates between the sugars. This review describes three newly identified DAEases that possess desirable properties for the industrial-scale manufacturing of D-allulose. Other methods used to enhance process efficiency include the engineering of DAEases for improved thermotolerance or acid resistance, the utilization of Bacillus subtilis for the biosynthesis of D-allulose, and the immobilization of DAEases to enhance its activity, half-life, and stability. All these research advancements improve the yield of D-allulose, hence closing the gap between the small-scale production and industrial-scale manufacturing of D-allulose.

Automated summary

This review discusses the potential use of three newly identified D-allulose 3-epimerases for the industrial-scale manufacturing of D-allulose. It also highlights other methods to enhance the process efficiency, such as improving the thermotolerance and acid resistance of D-allulose enzymes, utilizing Bacillus subtilis for the biosynthesis of D-allulose, and immobilizing D-allulose enzymes to enhance their activity, half-life, and stability. These research advancements have led to increased yields of D-allulose, bridging the gap between small-scale production and industrial-scale manufacturing.