Improvement of glucaric acid production in E. coli via dynamic control of metabolic fluxes

• Published in: Metabolic engineering communications 2015-12, Vol.2, p.109-116
• Main Authors: Reizman, Irene M. Brockman, Stenger, Andrew R., Reisch, Chris R., Gupta, Apoorv, Connors, Neal C., Prather, Kristala L.J.
• Format: Article
• Language: English
• Subjects: Dynamic metabolic engineering; Glucaric acid; Protein degradation; Synthetic biology
• ISSN: 2214-0301; 2214-0301
• DOI: 10.1016/j.meteno.2015.09.002

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 in Escherichia coli has 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 an E. coli strain where phosphofructokinase (Pfk) activity can be dynamically controlled and demonstrated its use for improving yields and titers of the glucaric acid precursor myo-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 via in situ enzymatic 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 modified E. coli strains. •Dynamic growth/production switching for glucaric acid production in E. coli.•Optimal time for switching via Pfk knockdown was screened in microtiter format.•Production from glucose was improved under batch conditions and with starch feeding.•Glucaric acid yield and titer improvements of up to 42% were achieved.