Abstract
BACKGROUND: Thymol and carvacrol are natural phenolic compounds with various biological activities. They are widely used in the spice and medicine industries. Production of thymol and carvacrol using microbial cell factories is considered a viable alternative to extracting them from plants of the Thymus genus or the Lamiaceae family. RESULTS: In this study, the complete synthetic pathways of thymol and carvacrol were constructed using the oleaginous yeast Yarrowia lipolytica Po1f as a chassis. The total titer of thymol and carvacrol was increased 18.44-fold by enhancing the mevalonate pathway during the modification process and reducing the metabolic flux from geranyl diphosphate (GPP) to farnesyl diphosphate (FPP) through the modification of ERG20. Next, by increasing the copy number of the TvCYP71D507 gene combination (TvCYP71D507 + TvTPS2 + TvSDR1) in the synthetic pathway, the total titer was increased by 1.75-fold. Finally, the engineered strain CT18, which was reintroduced the 3-isopropylmalate dehydrogenase (LEU2) gene, achieved a titer of thymol and carvacrol of 7.14 mg/L in shake flasks and 61.31 mg/L in a 5-L bioreactor. CONCLUSION: This study demonstrates the de novo synthesis of thymol and carvacrol in Y. lipolytica for the first time and provides a valuable reference for constructing microbial cell factories for phenolic monoterpenes biosynthesis.