De Novo Production of Glycyrrhetic Acid 3-O-mono- β-D-glucuronide in Saccharomyces cerevisiae

Ying Huang; Dan Jiang; Guangxi Ren; Yan Yin; Yifan Sun; Tengfei Liu; Chunsheng Liu

doi:10.3389/fbioe.2021.709120

De Novo Production of Glycyrrhetic Acid 3-O-mono- β-D-glucuronide in Saccharomyces cerevisiae

Front Bioeng Biotechnol. 2021 Nov 23:9:709120. doi: 10.3389/fbioe.2021.709120. eCollection 2021.

Authors

Ying Huang¹, Dan Jiang¹, Guangxi Ren¹, Yan Yin¹, Yifan Sun¹, Tengfei Liu², Chunsheng Liu¹

Affiliations

¹ School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China.
² Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China.

Abstract

Glycyrrhetic acid 3-O-mono-β-D-glucuronide (GAMG) is a rare compound in licorice and its short supply limits the wide applications in the pharmaceutical, cosmetic, and food industries. In this study, de novo biosynthesis of GAMG was achieved in engineered Saccharomyces cerevisiae strains based on the CRISPR/Cas9 genome editing technology. The introduction of GAMG biosynthetic pathway resulted in the construction of a GAMG-producing yeast strain for the first time. Through optimizing the biosynthetic pathway, improving the folding and catalysis microenvironment for cytochrome P450 enzymes (CYPs), enhancing the supply of UDP-glucuronic acid (UDP-GlcA), preventing product degradation, and optimizing the fermentation conditions, the production of GAMG was increased from 0.02 μg/L to 92.00 μg/L in shake flasks (4,200-fold), and the conversion rate of glycyrrhetic acid (GA) to GAMG was higher than 56%. The engineered yeast strains provide an alternative approach for the production of glycosylated triterpenoids.

Keywords: CRISPR/Cas9; Saccharomyces cerevisiae; cytochrome P450 enzymes (CYPs); glycyrrhetic acid 3-O-mono-β-D-glucuronide (GAMG); metabolic engineering.