Highly efficient synthesis of mono-β-1,6-Glucosylated Rebaudioside A derivative catalyzed by glycosyltransferase YjiC.

Steviol glycosides have attracted great interest because of their high levels of sweetness and safety, and absence of calories. Improvement of their sensory qualities via glycosylation modification by glycosyltransferase is a research hotspot. In this study, YjiC, a uridine diphosphate-dependent glycosyltransferase from Bacillus subtilis 168, was found with the ability to glycosylate rebaudioside A (Reb A) to produce a novel mono β -1, 6-glycosylated Reb A derivative rebaudioside L2 (Reb L2). It has an improved sweetness compared with Reb A. Next, a cascade reaction was established by combining YjiC with sucrose synthase At SuSy from Arabidopsis thaliana for scale-up preparation of Reb L2. It shows that Reb L2 (30.94 mg/mL) could be efficiently synthesized with an excellent yield of 91.34% within 12 h. Therefore, this study provides a potential approach for the production and application of new steviol glycoside Reb L2, expanding the scope of steviol glycosides. [Display omitted] • A glycosyltransferase YjiC from B. subtilis 168 was reported to synthesize a novel mono β -1,6-glycosylated Reb A derivative. • It was firstly reported that YjiC could realize the construction of β -1,6-glycosidic linkage. • Cascade reaction system with YjiC and sucrose synthase At SuSy from Arabidopsis thaliana was established to regenerate UDPG. • 29.01 mg/mL Reb A was transformed into 30.94 mg/mL Reb L2 with 91.34% yield in the cell lysate. [ABSTRACT FROM AUTHOR]