Sunday, August 11, 2013
Pavilion (Sheraton San Diego)
Sandalwood oil possesses a very pleasant and long lasting scent and is widely used in food and cosmetic industries. It is traditionally steam-distilled from the heartwood and the roots of the slow-growing Indian sandalwood (Santalum album L). This traditional method of extraction suffers from low yields and overharvesting the sandalwood trees. α-Santalene is the precursor of α-santalol, which represents up to 50% of natural sandalwood oil. It is synthesized from the universal precursors, isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP), which are generated either through the mevalonate (MVA) pathway or the 2C-methyl-D-erythritol-4-phosphate (MEP) pathway. Farnesyl pyrophosphate (FPP) synthase then catalyzes the condensation of IPP and DMAPP to the linear FPP, which is rearranged and cyclized by sesquiterpene synthases into various sesquiterpenes including α-santalene. Here,we constructed a heterologous biosynthesis pathway for α-santalene production. Manipulation of ribosome binding sites (RBS) or other RNA regulators offers a very effective alternative to tune expression of multiple genes. A set of synthetic RBSs were utilized to modulate diverse expression levels of FPP synthase and α-santalene synthase for the pathway optimization. By this approach, we have successfully produced α-santalene of > 400 mg/L, which is several folds higher than the reported production. This work was supported by a grant (NRF-2010-C1AAA001-0029084) from the National Research Foundation, the Intelligent Synthetic Biology Center of Global Frontier Project funded by the MEST (2011-0031964), and a grant from the Next-Generation BioGreen 21 Program (SSAC, grant#: PJ009522003), RDA, Korea.