Combinatorial engineering of Saccharomyces cerevisiae for improving limonene production

Limonene, a cyclized monoterpene, is a green chemical with growing applications in food, cosmetics, agriculture, materials, and energy in the coming bioeconomy era. In Saccharomyces cerevisiae, the precursor of mono-terpenoids is derived from the mevalonate pathway with acetyl-CoA as the starting substrate, which is the bottleneck for biosynthesis of limonene. Here, we provided the combinatorial engineering of S. cerevisiae for improvement of limonene production. Engineering the PDH bypass to directly push the acetyl-CoA flux into MVA pathway increased the production of limonene. Deleting target genes outside the MVA pathway benefited the biosynthesis of limonene. When combining the engineered PDH bypass with the deletion of CIT2 gene, the synergistic effect was observed. Finally, engineered yeast produced 2.23 g/L of limonene in fed-batch shake-flask fermentation. This study showed that metabolically engineered yeast possessed promising potential for industrial production of limonene.

Automated summary

Engineering Saccharomyces cerevisiae to improve limonene production by enhancing acetyl-CoA flux into the MVA pathway and deleting target genes outside the pathway resulted in increased limonene production. A synergistic effect was observed when combining the engineered PDH bypass with deletion of the CIT2 gene. The engineered yeast produced 2.23 g/L of limonene in fed-batch shake-flask fermentation, demonstrating promising potential for industrial production of limonene.