Project description:RpoS, an alternative sigma factor, is critical for stress response in Escherichia coli.RpoS also acts as a global regulator for stress control of gene expression, and actually dose so in log stage and stationary stage. To further understand the effect of environmental stresses on in ethanologenic strains, DNA microarrys was used to analyze the expression profiles of E. coli and its rpoS mutant strain. BW25113（rpoS-）and BW25113 were selected at log stages and stationary stage of early development for RNA extraction and hybridization on Affymetrix microarrays. To that end, we hand-selected BW25113 and BW25113（rpoS-） according at different treatments: BW25113（rpoS-）at log stage (BW25113(rpoS-) log), BW25113 at log stage (BW25113 log),BW25113（rpoS-）atstationary stage ( BW25113(rpoS-) stationary), BW25113 at stationary stage ( BW25113 stationary)
Project description:E. coli K-12 BW25113 persister cells generated via H202 pre-treatment and deletion of rpoS, relative to BW25113 wild-type stationary phase gene expression. Persister cells were generated following exposure to ampicillin 20 ug/mL.
Project description:This experiment examines the differences in global gene expression in a wild type and mutant strain grown under standard shaking conditions to mid log phase (OD600 0.5) followed by heat shock at 50C for 15 minutes.
Project description:The role of rpoS gene in the formation of Escherichia coli biofilms were investigated. The gene expression was compared among E. coli MG1655 wild type strain and rpoS knock-out strain in the biofilms, the planktonic exponential phase, and the planktonic stationary phase. The analysis revealed that the wild type bilfilms (WBF) showed similar pattern of gene expression with the WT planktonic stationary phase (WS), whereas the rpoS knock-out biofilms (MBF) showed similar pattern of gene expression with the wild type planktonic exponential phase (WE). Genes involved in the energy metabolism and the flagella synthesis showed higher expression in the rpoS knock-out biofilms (MBF), but not in the wild type biofilms (WBF). Moreover, genes involved in the stress responses showed higher expression in the wild type biofilms (WBF), but not in the rpoS knock-out biofilms (MBF). Keywords: cell type comparison (biofilms vs planktonic cells, wild type vs rpoS knock-out strains)
Project description:Transcriptional profiling of L. pneumophila JR32 (wild-type) and rpoS- (LM1376) strains grown to stat phase compared to cultures grown to log phase Keywords: growth phase
