Engineering of Saccharomyces cerevisiae towards synthesis of linalool using linalool synthase from Magnolia champaca

Abstract

Linalool is one of the commercially important fragrance molecule usually extracted from Lavandula angustifolia (lavender) and Ocimum basilicum (basil) plants. In the present study, efforts were made to produce this molecule in microbial system to meet demand-supply imbalance. Linalool synthase (LIS) gene from Magnolia champaca (Mc) and Coriandrum sativum (Cs) were successfully cloned and expressed in Saccharomyces cerevisiae CEN PK2–1 C. It was observed that expression of full-length LIS (fLIS) resulted in lesser linalool when compared to truncated LIS (tLIS) devoid of plastid signal for both Mc and Cs. In terms of linalool yield, MctLIS resulted in 1.27-fold higher linalool when compared to CstLIS. Later, when two more genes viz., TPI1 and ALD6 which presumably increase sterol pathway flux were overexpressed, actually resulted in lower linalool and increased acetate production. However, multicopy expression of MctLIS and tHMG1 in this strain has reversed the above phenomenon due to presumptive push-pull strategy. Finally, this engineered strain was cultivated in the 2 L bioreactor in fed-batch mode to obtain 10.85 µg/mL of linalool. Docking studies of homology model of MctLIS with geranyl pyrophosophate (GPP) revealed V387, Y361, T434, R427 and R249 as key interactions sites. The study reports the linalool production using LIS gene from Magnolia champaca for the first time and could be a potential chassis for further studies.