Efficient enzymatic synthesis of D-allulose using a novel D-allulose-3-epimerase from Caballeronia insecticola.

BACKGROUND: Rare sugars have become promising 'sugar alternatives' because of their low calories and unique physiological functions. Among the family of rare sugars, D-allulose is one of the sugars attracting interest. Ketose 3-epimerases (KEase), including D-tagatose 3-epimerase (DTEase) and D-allulose 3-epimerase (DAEase), are mainly used for D-allulose production.

RESULTS: In this study, a putative xylose isomerase from Caballeronia insecticola was characterized and identified as a novel DAEase. C. insecticola DAEase displayed prominent enzymatic properties, and 150 g/L D-allulose was produced from 500 g/L D-fructose in 45 min with a conversion rate of 30% and high productivity of 200 g/L/h. Furthermore, DAEase was employed in a phosphorylation-dephosphorylation cascade reaction, which significantly increased the conversion rate of D-allulose. Under optimized conditions, the conversion rate of D-allulose was approximately 100% when the concentration of D-fructose was 50 mM.

CONCLUSION: This research desccribed a very beneficial and facile approach for D-allulose production based on C. insecticola DAEase. This article is protected by copyright. All rights reserved.