Metabolomic and transcriptomic stress response of Escherichia coli

Abstract

Environmental fluctuations lead to a rapid adjustment of the physiology of E. coli, necessitating changes on every level of the underlying cellular and molecular network. Thus far, the vast majority of global analyses of E. coli stress responses have been limited to just one level - gene expression. In this chapter, the comparison and integration of the metabolite composition together with gene expression data is shown in order to provide a more comprehensive insight on system-level stress adjustments by describing detailed time-resolved responses of E. coli to five different perturbations. The comparative analysis of both data sets leads to the conclusion that the metabolic response is more specific as the general response observed on the transcript level. Moreover, this is reflected by a much higher specificity during the early stress adaptation phase and when comparing the stationary phase response to other perturbations. Despite these differences, the response on both levels still follows the same dynamics and general strategy of energy conservation as reflected by a rapid decrease of central carbon metabolism intermediates coinciding with down-regulation of genes related to cell growth.