Abstract
? 2022 Elsevier B.V.A novel D-allulose 3-epimerase (DAEase) from Arthrobacter psychrolactophilus (Ap DAEase) was first characterized in this study. The enzyme catalyzes the epimerization of D-fructose into a functional rare sugar, D-allulose. Ap DAEase was the first record of DAEase identified as a homotrimer with the molecular weight of its subunit at approximately 34 kDa. It had an optimum activity at pH 8.5 and 70 °C in the presence of 1 mM Mg2+. Ap DAEase was found to be an excellent thermostable enzyme. The half-life value at 70 °C was 128.4 min. The kcat and catalytic efficiency of the enzyme toward D-fructose were 2920.00 s?1 and 3.953 mM?1 s?1, respectively. To the best of our knowledge, Ap DAEase possesses the highest kcat among the previously reported DAEases. The conversion ratio of 500 and 100 mg L?1 D-fructose to D-allulose was approximately 27 % in 15 and 90 min, respectively. These research findings suggest that Ap DAEase is a promising candidate for the industrial production of D-allulose.
NSTL
Elsevier