title: Dynamic regulation of metabolic flux in engineered bacteria using a pathway-independent quorum-sensing circuit.
abstract: Metabolic engineering of microorganisms to produce desirable products on an industrial scale can result in unbalanced cellular metabolic networks that reduce productivity and yield. Metabolic fluxes can be rebalanced using dynamic pathway regulation, but few broadly applicable tools are available to achieve this. We present a pathway-independent genetic control module that can be used to dynamically regulate the expression of target genes. We apply our module to identify the optimal point to redirect glycolytic flux into heterologous engineered pathways in Escherichia coli, resulting in titers of myo-inositol increased 5.5-fold and titers of glucaric acid increased from unmeasurable to >0.8 g/L, compared to the parent strains lacking dynamic flux control. Scaled-up production of these strains in benchtop bioreactors resulted in almost ten- and fivefold increases in specific titers of myo-inositol and glucaric acid, respectively. We also used our module to control flux into aromatic amino acid biosynthesis to increase titers of shikimate in E. coli from unmeasurable to >100 mg/L.
authors.affiliation: Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.|Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Apoorv
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Irene M Brockman
authors.identifier: 0000-0003-0585-2213
authors.initials: IM
authors.lastname: Reizman
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Reisch
authors.affiliation: Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.|Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Kristala L J
authors.identifier: 0000-0003-0437-3157
authors.initials: KL
authors.lastname: Prather
mesh_terms: D003198:Computer Simulation; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D060847:Metabolic Engineering / Q000379:methods*; D064688:Metabolic Flux Analysis / Q000379:methods*; D055442:Metabolome / Q000502:physiology; D008954:Models, Biological; D053038:Quorum Sensing / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D029968:Escherichia coli Proteins