title: Metabolic engineering of Saccharomyces cerevisiae for itaconic acid production.
abstract: Renewable alternatives for petroleum-derived chemicals are achievable through biosynthetic production. Here, we utilize Saccharomyces cerevisiae to enable the synthesis of itaconic acid, a molecule with diverse applications as a petrochemical replacement. We first optimize pathway expression within S. cerevisiae through the use of a hybrid promoter. Next, we utilize sequential, in silico computational genome-scanning to identify beneficial genetic perturbations that are metabolically distant from the itaconic acid synthesis pathway. In this manner, we successfully identify three non-obvious genetic targets (∆ade3 ∆bna2 ∆tes1) that successively improve itaconic acid titer. We establish that focused manipulations of upstream pathway enzymes (localized refactoring) and enzyme re-localization to both mitochondria and cytosol fail to improve itaconic acid titers. Finally, we establish a higher cell density fermentation that ultimately achieves itaconic acid titer of 168 mg/L, a sevenfold improvement over initial conditions. This work represents an attempt to increase itaconic acid production in yeast and demonstrates the successful utilization of computationally guided genetic manipulation to increase metabolic capacity.
authors.affiliation: McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St. Stop C0400, Austin, TX, 78712, USA.
authors.forename: John
authors.initials: J
authors.lastname: Blazeck
authors.forename: Jarrett
authors.initials: J
authors.lastname: Miller
authors.forename: Anny
authors.initials: A
authors.lastname: Pan
authors.forename: Jon
authors.initials: J
authors.lastname: Gengler
authors.forename: Clinton
authors.initials: C
authors.lastname: Holden
authors.forename: Mariam
authors.initials: M
authors.lastname: Jamoussi
authors.forename: Hal S
authors.initials: HS
authors.lastname: Alper
mesh_terms: D053898:Biosynthetic Pathways; D005285:Fermentation; D060847:Metabolic Engineering; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013386:Succinates / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D013386:Succinates; C005229:itaconic acid