Engineered Bacillus subtilis harbouring gene of D-tagatose 3-epimerase for the bioconversion of D-fructose into D-psicose through fermentation

Publication date: Available online 4 February 2020Source: Enzyme and Microbial TechnologyAuthor(s): Jun Zhang, Chao Xu, Xiaoyan Chen, Xi Ruan, Yu Zhang, Huijuan Xu, Ying Guo, Jingliang Xu, Pengmei Lv, Zhongming WangAbstractD-psicose, as important rare sugar and epimer of D-fructose on the C-3 position, displays unique health benefits and physiological functions in various fields. The production of D-psicose is currently obtained via enzymatic bioconversion, mostly with of D-tagatose 3-epimerase. In the present study, the isomerization of D-fructose into D-psicose was achieved by constructing engineered food-grade Bacillus subtilis through fermentation. After optimizing the fermentation conditions of the recombinant strain, the yield of D-psicose reached up to 4.56 g/L, representing an over 8-fold increase in the yield compared to unoptimized conditions, with a D-fructose conversion rate of 56.26% when the strain was cultured at 35 ℃ for 24 h with 5 g/L D-fructose and 5 mM of Mn2+. In addition, 30 g of wasted apple hydrolysate were fermented by engineered B. subtilis and gained 7.76 g/L of D-psicose at a conversion rate of 25.86% (w/w).Graphical abstract
Source: Enzyme and Microbial Technology - Category: Biotechnology Source Type: research