Engineering Yarrowia lipolytica to Produce Itaconic Acid From Waste Cooking Oil

Itaconic acid (IA) is a high-value organic acid with a plethora of industrial applications. In this study, we seek to develop a microbial cell factory that could utilize waste cooking oil (WCO) as raw material for circular and cost-effective production of the abovementioned biochemical. Specifically, we expressed cis-aconitic acid decarboxylase (CAD) gene from <i>Aspergillus terreus</i> in either the cytosol or peroxisome of <i>Yarrowia lipolytica</i> and assayed for production of IA on WCO. To further improve production yield, the 10 genes involved in the production pathway of acetyl-CoA, an intermediate metabolite necessary for the synthesis of cis-aconitic acid, were individually overexpressed and investigated for their impact on IA production. To minimize off-target flux channeling, we had also knocked out genes related to competing pathways in the peroxisome. Impressively, IA titer up to 54.55 g/L was achieved in our engineered <i>Y. lipolytica</i> in a 5 L bioreactor using WCO as the sole carbon source.