Metabolic Engineering of Saccharomyces cerevisiae for Heterologous Carnosic Acid Production

Abstract

Carnosic acid (CA), a phenolic tricyclic diterpene, has many biological effects, including anti-inflammatory, anticancer, antiobesity, and antidiabetic activities. In this study, an efficient biosynthetic pathway was constructed to produce CA in Saccharomyces cerevisiae. First, the CA precursor miltiradiene was synthesized, after which the CA production strain was constructed by integrating the genes encoding cytochrome P450 enzymes (P450s) and cytochrome P450 reductase (CPR) SmCPR. The CA titer was further increased by the coexpression of CYP76AH1 and SmCPR ∼t28SpCytb5 fusion proteins and the overexpression of different catalases to detoxify the hydrogen peroxide (H2O2). Finally, engineering of the endoplasmic reticulum and cofactor supply increased the CA titer to 24.65 mg/L in shake flasks and 75.18 mg/L in 5 L fed-batch fermentation. This study demonstrates that the ability of engineered yeast cells to synthesize CA can be improved through metabolic engineering and synthetic biology strategies, providing a theoretical basis for microbial synthesis of other diterpenoids.

Controlled Production of Carnosic Acid and Carnosol in Cell Suspensions of Lepechinia meyenii Treated with Different Elicitors and Biosynthetic Precursors

“…Despite the cells suspension of L. meyenii represents a good system to evaluate diverse elicitors and precursors involved in CA and CS biosynthesis, the production of other compounds should be further addressed. Recent studies based on metabolic engineering have been reported recombinant yeasts able to produce 76 mg L −1 under bioreactor conditions [35] . Nevertheless, only traces of CS (which also shows a wide spectrum biological activities) were detected in this system.…”

“…Recent studies based on metabolic engineering have been reported recombinant yeasts able to produce 76 mg L À 1 under bioreactor conditions. [35] Nevertheless, only traces of CS (which also shows a wide spectrum biological activities) were detected in this system. Due to this fact, cell suspension of L. meyenii represent a generous advantage on CS production.…”