title: A Glucose-Sensing Toggle Switch for Autonomous, High Productivity Genetic Control.
abstract: Many biosynthetic strategies are coupled to growth, which is inherently limiting, as (1) excess feedstock (e.g., sugar) may be converted to biomass, instead of product, (2) essential genes must be maintained, and (3) growth toxicity must be managed. A decoupled growth and production phase strategy could avoid these issues. We have developed a toggle switch that uses glucose sensing to enable this two-phase strategy. Temporary glucose starvation precisely and autonomously activates product pathway expression in rich or minimal media, obviating the requirement for expensive inducers. The switch remains stably in the new state even after reintroduction of glucose. In the context of polyhydroxybutyrate (PHB) biosynthesis, our system enables shorter growth phases and comparable titers to a constitutively expressing PHB strain. This two-phase production strategy, and specifically the glucose toggle switch, should be broadly useful to initiate many types of genetic program for metabolic engineering applications.
authors.affiliation: Department of Chemical and Biological Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: William
authors.identifier: 0000-0002-7329-0286
authors.initials: W
authors.lastname: Bothfeld
authors.affiliation: Department of Chemical and Biological Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Grace
authors.initials: G
authors.lastname: Kapov
authors.affiliation: Department of Chemical and Biological Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Keith E J
authors.initials: KEJ
authors.lastname: Tyo
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D005947:Glucose / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*
chemical_list: D006885:Hydroxybutyrates; D005947:Glucose
keywords: PHB production; genetic toggle switch; glucose sensing; metabolic engineering