Metabolic Engineering of Yarrowia Lipolytica for the Production of Itaconic Acid

Itaconic acid has gained recognition as a commodity chemical for its utility as a copolymer in plastics as well as the use of polyitaconic acid as a replacement for polyacrylic acid.  Moreover, this molecule was reported as one of the top 12 value-added chemicals from biomass by the 2004 DOE report.  Current industrial-scale bio-production of itaconic acid using the native host, Aspergillus terreus, suffers from organism-level limitations including poor growth in media optimal for itaconic acid production and low tolerance of the shear stress associated with bioreactor fermentations.  Here, we report the highest level production in a non-native host through the rewiring of the oleaginous yeast, Yarrowia lipolytica.  Specifically, we first introduce the itaconic acid biosynthesis pathway to achieve an initial production at 33 mg/L.  Next, through a series of genetic engineering and media optimization steps, we have been able to increase the titer over 100-fold to achieve g/L levels.  Through this work, we have been able to engineer Y. lipolytica for the production of itaconic acid with industrially relevant titers and conditions, providing a platform for further process optimization.