Balancing Pyruvate Node Based on a Dual-Layered Dynamic Regulation System to Improve the Biosynthesis of Caffeic Acid in Candida glycerinogenes

Abstract

Caffeic acid is a phenolic acid compound widely applied in the food and pharmaceutical fields. Currently, one of the reasons for the low yield of caffeic acid biosynthesis is that the carbon flow enters mainly into the TCA cycle via pyruvate, which leads to low concentrations of erythrose 4-phosphate (E4P) and phosphoenolpyruvate (PEP), the precursors of caffeic acid synthesis. Here, we developed a growth-coupled dual-layered dynamic regulation system. This system controls intracellular pyruvate supply in real time by responding to intracellular pyruvate and p-coumaric acid concentrations, autonomously coordinates pathway gene expression, and redirects carbon metabolism to balance cell growth and caffeic acid synthesis. Finally, our constructed engineered strain based on the dual-layered dynamic regulation system achieved a caffeic acid titer of 559.7 mg/L in a 5 L bioreactor. Thus, this study demonstrated the efficiency and potential of this system in boosting the yield of aromatic compounds.

Lighting up Pyruvate Metabolism in Saccharomyces cerevisiae by a Genetically Encoded Fluorescent Biosensor

“…As a metabolic hub in central carbon metabolism, pyruvate is a useful metabolic precursor for many chemicals, including food additives, pharmaceuticals, and polymers . Moreover, pyruvate also can act as a significant signaling molecule to tune the synthesis of a variety of central metabolism-related chemicals. − Thus, more and more research is working on carbon flux control using pyruvate as a node through dynamic regulation of biosynthetic pathways for improving the production of various chemicals. For example, a pyruvate-driven metabolic scenario has been designed for growth-coupled microbial production of anthranilate, chorismate, and their derivatives. , Recently, pyruvate-responsive genetic circuits were developed to dynamically control central metabolism to improve the production of glucaric acid .…”