Construction of a platform Saccharomyces cerevisiae for the production of muconic acid
Miguel Suástegui1, John Matthiesen1, Jean-Philippe Tessonnier1 & Zengyi Shao1*
1 Department of chemical and Biological Engineering, Iowa State University
2 Corresponding author (firstname.lastname@example.org)
Molecules deriving from the aromatic amino acid biosynthetic pathway have a great market opportunity. The chemical versatility of aromatic compounds can be exploited in various industries for examples for the production of polymers, pharmaceuticals, cosmetics, and nutraceuticals. In this work we focused on accumulation of 3-dehydroshikimate (DHS), a key aromatic compound used as precursor for the heterologous production of muconic acid. Flux balance analysis allowed constructing a platform Saccharomyces cerevisiae strain capable of accumulating the main precursors erythrose-4-phosphae (E4P) and phosphoenolpyruvate (PEP). Aided by 13-C metabolic flux analysis, the main rationale consisted on removing competing pathways, removing feedback inhibition, and overexpression of genes in the lower glycolytic node as well as in the non-oxidative part of the pentose phosphate pathway. The combination of these strategies and fermentation optimization allowed increasing the production of muconic acid around 5-fold of a previously reported S. cerevisiae strain. The biologically derived muconic acid was then electrochemically hydrogenated to 3-hexenedioic acid (3-HDA) at high conversion rates without the need for separation or cell clarification; potentially this molecule can be polymerized to obtain nylon-like polymers.