Engineering Yarrowia lipolytica for Efficient Synthesis of Geranylgeraniol.

ABSTRACT

Geranylgeraniol (GGOH) is a crucial component in fragrances and essential oils, and a valuable precursor of vitamin E. It is primarily extracted from the oleoresin of Bixa orellana, but is challenged by long plant growth cycles, severe environmental pollution, and low extraction efficiency. Chemically synthesized GGOH typically comprises a mix of isomers, making the separation process both challenging and costly. Advancements in synthetic biology have enabled the construction of microbial cell factories for GGOH production. In this study, Yarrowia lipolytica was engineered to efficiently synthesize GGOH by expressing heterologous phosphatase genes, enhancing precursor supplies of farnesyl diphosphate, geranylgeranyl pyrophosphate, and acetyl-CoA, and downregulating the squalene synthesis pathway by promoter engineering. Additionally, optimizing fermentation conditions and reducing reactive oxygen species significantly increased the GGOH titer to 3346.47 mg/L in a shake flask. To the best of our knowledge, this is the highest reported GGOH titer in shaking flasks to date, setting a new benchmark for terpenoid production.