Metabolic Engineering of <i>Saccharomyces cerevisiae</i> for High-Level Production of Chlorogenic Acid from Glucose
Feng Xiao, Jiazhang Lian, Shuai Tu, Linlin Xie, Jun Li, Fuming Zhang, Robert J. Linhardt, Haichan Huang, Weihong Zhong
Abstract
Chlorogenic acid (CGA), a major dietary phenolic compound, has been increasingly used in the food and pharmaceutical industries because of its ready availability and extensive biological and pharmacological activities. Traditionally, extraction from plants has been the main approach for the commercial production of CGA. This study reports the first efficient microbial production of CGA by engineering the yeast, Saccharomyces cerevisiae, on a simple mineral medium. First, an optimized de novo biosynthetic pathway for CGA was reconstructed in S. cerevisiae from glucose with a CGA titer of 36.6 ± 2.4 mg/L. Then, a multimodule engineering strategy was employed to improve CGA production: (1) unlocking the shikimate pathway and optimizing carbon distribution; (2) optimizing the l-Phe branch and pathway balancing; and (3) increasing the copy number of CGA pathway genes. The combination of these interventions resulted in an about 6.4-fold improvement of CGA titer up to 234.8 ± 11.1 mg/L in shake flask cultures. CGA titers of 806.8 ± 1.7 mg/L were achieved in a 1 L fed-batch fermenter. This study opens a route to effectively produce CGA from glucose in S. cerevisiae and establishes a platform for the biosynthesis of CGA-derived value-added metabolites.