title: Improvement of glucaric acid production inE. colivia dynamic control of metabolic fluxes.
abstract: D-glucaric acid can be used as a building block for biopolymers as well as in the formulation of detergents and corrosion inhibitors. A biosynthetic route for production inE. colihas been developed (Moon et al., 2009), but previous work with the glucaric acid pathway has indicated that competition with endogenous metabolism may limit carbon flux into the pathway. Our group has recently developed anE. colistrain where phosphofructokinase (Pfk) activity can be dynamically controlled and demonstrated its use for improving yields and titers of the glucaric acid precursormyo-inositol on glucose minimal medium. In this work, we have explored the further applicability of this strain for glucaric acid production in a supplemented medium more relevant for scale-up studies, both under batch conditions and with glucose feeding viain situenzymatic starch hydrolysis. It was found that glucaric acid titers could be improved by up to 42% with appropriately timed knockdown of Pfk activity during glucose feeding. The glucose feeding protocol could also be used for reduction of acetate production in the wild type and modifiedE. colistrains.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Irene M Brockman
authors.initials: IM
authors.lastname: Reizman
authors.affiliation: Research Institute for Scientists Emeriti, Drew University, Madison, NJ 07940, USA.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Stenger
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Chris R
authors.initials: CR
authors.lastname: Reisch
authors.affiliation: Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA ; Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Apoorv
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Research Institute for Scientists Emeriti, Drew University, Madison, NJ 07940, USA ; Kalion, Inc., Milton, MA 02186, USA.
authors.forename: Neal C
authors.initials: NC
authors.lastname: Connors
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA ; Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Kristala L J
authors.initials: KL
authors.lastname: Prather
keywords: Dynamic metabolic engineering; Glucaric acid; Protein degradation; Synthetic biology