Metabolic Engineering of Filamentous Fungus <i>Trichoderma reesei</i> for Itaconic Acid Production

Itaconic acid (IA) is a multifunctional platform chemical with numerous biological functions. Here, <i>Trichoderma reesei</i> was engineered as a remarkable cell factory to produce IA. Heterologous overexpression of the mitochondrial tricarboxylate transport protein and <i>cis</i>-aconitate decarboxylase from <i>Aspergillus terreus</i> in <i>T. reesei</i> initiated IA production with a titer of 20 g/L. By increasing the copy number of <i>mttA</i> and <i>cadA</i> and the overexpression of the plasma membrane transporter proteins (MFSA), the titer of IA reached 56.7 g/L. The precursor synthesis pathway of IA was overexpressed by the overexpression of aconitase and citrate synthase, and the IA competition pathway was blocked by the deletion of the P450 monooxygenase gene <i>cyp3</i> to further enhance IA production. The final strain resulted in a final IA titer of 93.5 g/L through fed-batch fermentation in a 1 L bioreactor. Our study demonstrates that <i>T. reesei</i> can serve as a relevant platform in industry for IA production.