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 beta-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 AtSuSy 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.

Automated summary

This study discovered that YjiC, a uridine diphosphate-dependent glycosyltransferase from Bacillus subtilis 168, has the ability to glycosylate rebaudioside A (Reb A) and produce a novel mono beta-1, 6-glycosylated Reb A derivative called rebaudioside L2 (Reb L2), which has improved sweetness compared to Reb A. The researchers also established a cascade reaction by combining YjiC with sucrose synthase AtSuSy from Arabidopsis thaliana, allowing for efficient synthesis of Reb L2 with a yield of 91.34% within 12 hours. This study provides a potential approach for the production and application of the new steviol glycoside Reb L2, expanding the scope of steviol glycosides.