One-pot cascade reaction coupling a microbial glycosyltransferase to sucrose synthase for high-level production of cinnamyl alcohol mono-glucoside

Cinnamyl alcohol mono-glucoside (rosin), one of the important ingredients in Rhodiola rosea, displays many biological activities. The traditional production of rosin is direct extraction, which suffers from limited avail-ability of natural resources. This study developed an efficient method for the product of cinnamyl alcohol mono-glucoside using a one-pot cascade reaction by a microbial glycosyltransferase UGTBL1 coupled with sucrose synthase (GmSuSy) from Glycine max. By optimizing the conditions of the UGTBL1-GmSuSy coupled reaction, a high yield of cinnamyl alcohol mono-glucoside could be achieved and it showed good compatibility between the microbial glycosyltransferase UGTBL1 and sucrose synthase GmSuSy for cinnamyl alcohol mono-glucoside for-mation and UDPG regeneration. Using a fed-batch strategy, cinnamyl alcohol mono-glucoside could reach a high titer of 9.96 g/L with a conversion of 90.8 % in the one-pot cascade reaction. This study lays a significant foundation for the enzymatic production of rosin using glycosyltransferase and sucrose synthase-coupled cascade reactions.