Characteristics of a fructose 6-phosphate 4-epimerase from Caldilinea aerophila DSM 14535 and its application for biosynthesis of tagatose

• Published in: Enzyme and microbial technology 2020-09, Vol.139, p.109594-109594, Article 109594
• Main Authors: Dai, Yiwei, Zhang, Jinxiu, Zhang, Tao, Chen, Jingjing, Hassanin, Hinawi AM, Jiang, Bo
• Format: Article
• Language: English
• Subjects: C4 epimerization; Fructose; Maltodextrin; Tagatose
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2020.109594

•An enzyme, GatZ, used for the C4 epimerization of fructose 6-phosphate, was characterized.•This enzyme was thermostable and showed maximum activity at 70 °C and a pH of 8.0.•This enzyme was involved in a multi-enzyme catalytic system that can produce tagatose from maltodextrin. Tagatose is a rare hexoketose with potential health benefits. Here, an enzyme, GatZ subunit ofd-tagatose-1,6-bisphosphate aldolase, was characterized. GatZ is involved in a multi-enzyme cascade reaction system that can produce tagatose from maltodextrin. It showed maximum activity at 70 °C and a pH 8.0, and required supplementation with 5 mM Mg2+ to achieve the highest catalytic activity. The Km and Vmax values of GatZ using fructose 6-phosphate as substrate were 5.66 mM and 0.0329 mmol/L min, respectively. An in vitro multi-enzyme system containing GatZ was constructed, and 1.75 g/L tagatose was produced from 5 g/L maltodextrin after 10 h. This biosystem could potentially enrich the application of C4 epimerases in rare sugar bioproduction.