Metabolic engineering of Saccharomyces cerevisiae for production of ginsenoside

Abstract

Ginsenoside is a unique tri-terpene secondary metabolite of genus Panax also known as popular bioactive components that help with various physiological phenomena and diverse pharmacological activities. Due to revealed efficacy for various diseases and disorders

anti-inflammation, hepatoprotection, tumor cell apoptosis, anti-aging, memory enhancing, cardiovascular enhancing and preventing metabolic disorders such as diabetes and obesity, ginsenosides considered as important ingredient for modern medicine. However, traditional farming-based ginsenoside production circumstance limited ginsenoside production qualitative and quantitative.

In this study, metabolic engineering of the yeast Saccharomyces cerevisiae was used for the efficient production of skeletal terpenes of ginsenosides, dammarenediol-ii (DMD-ii) and protopanaxadiol (PPD).For the production of dammarenediol-ii and protopanaxadiol in S. cerevisiae, we introduced multiple heterologous genes

dammarenediol synthase (DDS), codon optimized protopanaxadiol synthase (PPDS) from Panax ginseng and NADPH-cytochrome P450 reductase from Arabidopsis thaliana (ATR1). Overexpression of truncated 3-hydroxy-3-methylglutaryl-CoA reductase (tHMG1), squalene synthase (ERG9), 2,3-oxidosqualene synthase (ERG1) genes were performed to increase the precursor flux by strengthening the innate mevalonate pathway. The genes lipid phosphate phosphatase (LPP1) and diacylglycerol pyrophosphate (DPP1) were deleted to construct dpp1Δlpp1Δ strain that prevented the transition of farnesyl pyrophosphate (FPP), the critical terpenoid precursor, to farnesol. The dpp1Δlpp1Δ strain produced 61.44 mg/L of DMD-ii or 25.12 mg/L of PPD from 20 g/L of glucose in minimal SC medium.

Finally, multiple copies of the gene DDS1 were integrated into delta site of yeast chromosome to construct CEN.PK2-1C dpp1Δlpp1Δδ::DDS1 strain that produced 14.74 mg/L of DMD-ii from 20 g/L of glucose in SC medium without further gene manipulation.