D-Allulose 3-epimerase of Bacillus sp. origin manifests profuse heat-stability and noteworthy potential of D-fructose epimerization.

ABSTRACT:

Background

D-Allulose is an ultra-low calorie sugar of multifarious health benefits, including anti-diabetic and anti-obesity potential. D-Allulose 3-epimerase family enzymes catalyze biosynthesis of D-allulose via epimerization of D-fructose.

Results

A novel D-allulose 3-epimerase (DaeB) was cloned from a plant probiotic strain, Bacillus sp. KCTC 13219, and expressed in Bacillus subtilis cells. The purified protein exhibited substantial epimerization activity in a broad pH spectrum, 6.0-11.0. DaeB was able to catalyze D-fructose to D-allulose bioconversion at the temperature range of 35?°C to 70?°C, exhibiting at least 50?% activity. It displaced excessive heat stability, with the half-life of 25?days at 50?°C, and high turnover number (k_cat 367?s^-?1). The coupling of DaeB treatment and yeast fermentation of 700?g L^-?1 D-fructose solution yielded approximately 200?g L^-?1 D-allulose, and 214?g L^-?1 ethanol.

Conclusions

The novel D-allulose 3-epimerase of Bacillus sp. origin discerned a high magnitude of heat stability along with exorbitant epimerization ability. This biocatalyst has enormous potential for the large-scale production of D-allulose.

SUBMITTER: Patel SN 

PROVIDER: S-EPMC7934257 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature