Combining Protein and Organelle Engineering for Linalool Overproduction in Saccharomyces cerevisiae

Linalool, a plant-derived high-value monoterpene, is widely used in the perfume, cosmetic, and pharmaceutical industries. Recently, engineering microbes to produce linalool has become an attractive alternative to plant extraction or chemical synthesis approaches. However, the low catalytic activity of linalool synthase and the shortage of precursor pools have been considered as two key factors for low yields of linalool. In this study, we rationally engineered the entrance of the substrate-binding pocket of linalool synthase (t67OMcLIS_M) and successfully increased the catalytic efficiency of this enzyme toward geranyl pyrophosphate. Specifically, F447E and F447A, with decreased entrance hydrophobicity and steric hindrance, increased linalool production by 2.2 and 1.9 folds, respectively. Subsequently, cytoplasm and peroxisomes were harnessed to boost linalool synthesis in Saccharomyces cerevisiae, achieving a high titer of linalool (219.1 mg/L) in shake-flask cultivation. Finally, the engineered diploid strain produced 2.6 g/L of linalool by 5 L fed-batch fermentation, which was the highest production in yeast to date. The protein engineering and biosynthetic pathway compartmentalization in the peroxisome provide references for the microbial production of other monoterpenes.