[Construction of oleanolic acid-producing Saccharomyces cerevisiae cells]

Area of Science:

• Metabolic Engineering
• Synthetic Biology
• Biotechnology

Context:

• Oleanolic acid is a pentacyclic triterpenoid with significant pharmacological potential.
• Developing sustainable and efficient biosynthesis routes is crucial for its production.
• Saccharomyces cerevisiae offers a robust platform for heterologous compound synthesis.

Purpose:

• To engineer Saccharomyces cerevisiae for the de novo biosynthesis of oleanolic acid.
• To optimize precursor and cofactor (NADPH) supply pathways for enhanced production.
• To improve oleanolic acid yield through iterative metabolic engineering strategies.

Summary:

• Heterologous expression of key enzymes (β-AS, CYP716A154, AtCPR) initiated oleanolic acid synthesis in S. cerevisiae.
• Overexpression of pentose phosphate pathway (PPP) enzymes, POS5, tPgHMGR1, and SmFPS increased squalene and oleanolic acid precursor supply.
• Increasing gene copy numbers of heterologous genes and optimizing precursor/cofactor supply led to a 10-fold increase in oleanolic acid yield (53.96 mg·L⁻¹).

Impact:

• Established a foundation for the green biosynthesis of oleanolic acid.
• Demonstrated a successful metabolic engineering approach for pentacyclic triterpenoid production in S. cerevisiae.
• Provides a valuable reference for engineering other valuable natural products in yeast systems.