Project description:We measured transcriptional changes in an effort to understand mechanisms of action resulting from the introduction of global transcriptional machinery engineering in E. coli in the presence and absence of ethanol. Keywords: repeat
Project description:We measured transcriptional changes in an effort to understand mechanisms of action resulting from the introduction of global transcriptional machinery engineering in E. coli in the presence and absence of ethanol. Experiment Overall Design: We explored two types of experimental factors: genetic variation (mutated transcriptional machinery) and environmental variation (ethanol concentration).
Project description:We successfully isolated an E. coli strain harboring rpoD mutant B8 with 2% (v/v) butanol tolerance using global transcriptional machinery engineering approach. DNA microarrays were employed to assess the transcriptome profile of n-butanol tolerance strain B8 and control strain E. coli JM109. The goal of this study is therefore to identify E. coli genes that are involved in n-butanol tolerance.
Project description:Escherichia coli exhibits diauxic growth in sugar mixtures due to CRP-mediated catabolite repression and inducer exclusion related to phosphotransferase system enzyme activity. Replacement of the native crp gene with a catabolite repression mutant (referred to as crp*) alleviates diauxic effects in E. coli and enables co-utilization of glucose and other sugars. While previous studies have examined the effects of expressing CRP* mutants on the expression of specific catabolic genes, little is known about the global transcriptional effects of CRP* expression. In this study, we compare the transcriptome of E. coli W3110 (expressing wild-type CRP) to that of mutant strain PC05 (expressing CRP*) in the presence and absence of glucose.
Project description:We investigated the impact of cadmium on the global transcriptome of E. coli wild type, ∆gshA and ∆gshB mutant cells to evaluate the molecular basis of cadmium toxicity in the presence or absence of cellular thiols. This global transcriptome analysis were done with cells synthezising GSH (wild type), gamma-glutamyl-cysteine (∆gshB mutant) or neither of the two cellular thiols (∆gshA mutant) under the influence of 100 µM Cd(II).
Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
Project description:Escherichia coli exhibits diauxic growth in sugar mixtures due to CRP-mediated catabolite repression and inducer exclusion related to phosphotransferase system enzyme activity. Replacement of the native crp gene with a catabolite repression mutant (referred to as crp*) alleviates diauxic effects in E. coli and enables co-utilization of glucose and other sugars. While previous studies have examined the effects of expressing CRP* mutants on the expression of specific catabolic genes, little is known about the global transcriptional effects of CRP* expression. In this study, we compare the transcriptome of E. coli W3110 (expressing wild-type CRP) to that of mutant strain PC05 (expressing CRP*) in the presence and absence of glucose. Experiment Overall Design: Four different conditions were tested in this study: W3110 in LB medium (WT), W3110 in LB+glucose medium (WT G), PC05 in LB medium (CRP*), and PC05 in LB+glucose medium (CRP* G).
Project description:Transcript abundance in Escherichia coli O157:H7 was determined in the presence or absence of pulsed expression of the small RNA, AsxR.
Project description:n-Butanol has been proposed as an alternative biofuel to ethanol, and both Escherichia coli and Saccharomyces cerevisiae have been engineered to produce it. Unfortunately, n-butanol is more toxic than ethanol to these organisms. To understand the basis for its toxicity, cell wide studies were conducted at the transcript, protein and metabolite levels to obtain a global view of the n-butanol stress response. Analysis of the data indicate that n-butanol stress has components common to other stress responses and includes perturbation in respiratory functions (nuo, cyo operons), oxidative stress (sodC, katG, yqhD), heat shock and cell envelope stress (rpoE, clpB, htpG, degP, cpxPR), metabolite transport (malE, opp operon) and biosynthesis. Inducible expression of the yqhD gene was found to improve the host’s tolerance to exogenous n-butanol and confirms the role of this gene in coping with butanol stress. To survey for other potential candidates that may serve to improve host tolerance, mutant strains in several candidates which show changes at the transcript and protein levels were examined for sensitivity during butanol exposure. Chassis engineering based on these cues may be required in a high production titer, butanol-producing host.
