Optimized biosynthesis of santalenes and santalols in Saccharomyces cerevisiae

Santalenes and santalols from Santalum album are the main components of the valuable spice sandalwood essential oil, which also has excellent pharmacological activities such as antibacterial, anti-inflammatory, and antitumor. Firstly, we constructed biosynthesis pathways of santalenes by synthetic biology strategy. The assembled biosynthetic cassettes were integrated into the multiple copy loci of delta gene in S. cerevisiae BY4742 with assistance of pDi-CRISPR, and 94.6 mg/L santalenes was obtained by shake flask fermentation of engineered yeast. Secondly, a selected optimized P450-CPR redox system was integrated into the chromosome of the santalenes-producing strain with a single copy, and 24.6 mg/L santalols were obtained. Finally, the yields of santalenes and santalols were increased to 164.7 and 68.8 mg/L, respectively, by downregulating ERG9 gene. This is the first report on the de novo synthesis of santalols by P450-CPR chimera in S. cerevisiae. Meanwhile, the optimized chimeric CYP736A167(opt)-46tATR1(opt) exhibits higher activity to oxidize santalenes into santalols. It would provide a feasible solution for the optimal biosynthesis of santalols.

Automated summary

The study focused on biosynthesis of santalenes and santalols from sandalwood essential oil using synthetic biology strategy in S. cerevisiae, achieving high yields by integrating optimized P450-CPR redox system and downregulating ERG9 gene. The research provides a feasible solution for optimal biosynthesis of santalols.