A synthetic growth switch based on controlled expression of RNA polymerase

Abstract : The ability to control growth is essential for fundamental studies of bacterial physiology and biotechnological applications. We have engineered an Escherichia coli strain in which the transcription of a key component of the gene expression machinery, RNA polymerase, is under the control of an inducible promoter. By changing the inducer concentration in the medium, we can adjust the RNA polymerase concentration and thereby switch bacterial growth between zero and the maximal growth rate supported by the medium. We show that our synthetic growth switch functions in a medium-independent and reversible way, and we provide evidence that the switching phenotype arises from the ultrasensitive response of the growth rate to the concentration of RNA polymerase. We present an application of the growth switch in which both the wild-type E. coli strain and our modified strain are endowed with the capacity to produce glycerol when growing on glucose. Cells in which growth has been switched off continue to be metabolically active and harness the energy gain to produce glycerol at a twofold higher yield than in cells with natural control of RNA polymerase expression. Remarkably, without any further optimization, the improved yield is close to the theoretical maximum computed from a flux balance model of E. coli metabolism. The proposed synthetic growth switch is a promising tool for gaining a better understanding of bacterial physiology and for applications in synthetic biology and biotechnology.
Liste complète des métadonnées

https://hal.inria.fr/hal-01247993
Contributeur : Hidde De Jong <>
Soumis le : mercredi 23 décembre 2015 - 11:53:50
Dernière modification le : jeudi 11 janvier 2018 - 06:23:27

Identifiants

  • HAL Id : hal-01247993, version 1
  • PUBMED : 26596932

Collections

Citation

Jérôme Izard, Cindy Gomez-Balderas, Delphine Ropers, Stephan Lacour, Xiaohu Song, et al.. A synthetic growth switch based on controlled expression of RNA polymerase. Molecular Systems Biology, EMBO Press, 2015, 11 (11), pp.840. 〈http://msb.embopress.org/content/11/11/840〉. 〈hal-01247993〉

Partager

Métriques

Consultations de la notice

202