Project description:Responses of Escherichia coli MG1655/pTrc99a(NOX-) grown at different growth rates in chemostat in M9 + salts Keywords: different growth rates in parallel
Project description:Responses of Escherichia coli MG1655/pTrc99a(NOX+) grown at different growth rates in chemostat in M9 + salts NOX: NADH oxygenase converts NADH to NAD. Cells with NOX are able to recycle the excess NADH generated during rapid growth, leading to lesser accumulation of acetate Keywords: different growth rates in parallel
Project description:The gene expression profile of E. coli K-12 MG1655 grown in minimal medium supplemented with elevated copper concentrations (as copper-glycine) has been analysed using whole genome oligonucleotide microarrays. “Pool” RNA was isolated from five independently grown 50ml DMA cultures of E. coli K-12 MG1655. “Test” RNA was isolated from three independently grown 50ml DMA cultures of E. coli K-12 MG1655, for each growth condition (no added CuSO4, or supplemented with either 0.75mM or 2mM copper glycine). A sample of each culture was taken at mid to late exponential growth phase at OD600 0.8 (measured using a Pharmacia Biotech Ultrospec 2000 in a cuvette with a path length of 10mm). Keywords: dose response
Project description:E. coli MG155 cells were grown at different grwoth rates in mixed substrate culture. To facilitate different metaoblic status, cells adjust substrate consumption behavior which must be reflected in the gene expression profiles of metablism network. The metabolism network including the substrate transporter systems is our study focus. We use microarrays to capture the adjustments and switches in substrate transporter and central metabolism network along growth rate changes.
Project description:The gene expression profile of E. coli K-12 MG1655 grown in minimal medium treated with 0.12 mg/L of the biocide triclosan has been analysed using whole genome oligonucleotide microarrays. "Control" RNA was isolated from three independently grown 50ml MOPS minimal media cultures of E. coli K-12 MG1655. “Test” RNA was isolated from three independently grown 50ml MOPS minimal cultures of E. coli K-12 MG1655, to which was added 0.12 mg/L of triclosan after reaching mid-logarithmic growth phase (OD600 ~ 0.7 +/- 0.02). Keywords: dose response
Project description:The gene expression profile of E. coli K-12 MG1655 grown in minimal medium supplemented with elevated copper concentrations (as copper-glycine) has been analysed using whole genome oligonucleotide microarrays. â??Poolâ?? RNA was isolated from five independently grown 50ml DMA cultures of E. coli K-12 MG1655. â??Testâ?? RNA was isolated from three independently grown 50ml DMA cultures of E. coli K-12 MG1655, for each growth condition (no added CuSO4, or supplemented with either 0.75mM or 2mM copper glycine). A sample of each culture was taken at mid to late exponential growth phase at OD600 0.8 (measured using a Pharmacia Biotech Ultrospec 2000 in a cuvette with a path length of 10mm).
Project description:The gene expression profile of E. coli K-12 MG1655 grown in minimal medium treated with 0.12 mg/L of the biocide triclosan has been analysed using whole genome oligonucleotide microarrays. "Control" RNA was isolated from three independently grown 50ml MOPS minimal media cultures of E. coli K-12 MG1655. âTestâ RNA was isolated from three independently grown 50ml MOPS minimal cultures of E. coli K-12 MG1655, to which was added 0.12 mg/L of triclosan after reaching mid-logarithmic growth phase (OD600 ~ 0.7 +/- 0.02). Keywords: dose response Cy5-labelled cDNA probes were synthesised from three independent biological extractions of RNA from E. coli MG1655 unexposed to triclosan. Cy3-labelled cDNA probes were synthesised from three independent biological extractions of RNA from E. coli MG1655 exposed to 0.12 mg/L of triclosan. A dye-swap control was also included, whereupon the control cDNA probes were labelled with Cy3 and the test cDNA probes labelled with Cy5. Probes were mixed to allow comparison of the control and test expression profiles and hybridised onto an E. coli spotted oligonucleotide array.
Project description:E. coli MG155 cells were grown at different grwoth rates in mixed substrate culture. To facilitate different metaoblic status, cells adjust substrate consumption behavior which must be reflected in the gene expression profiles of metablism network. The metabolism network including the substrate transporter systems is our study focus. We use microarrays to capture the adjustments and switches in substrate transporter and central metabolism network along growth rate changes. E. coli MG155 cells were cultured in a continuous-feed chemostat culture with growth rate control through dilution. Cells were confirmed with a stable growth rate then collected and analyzed 24 hrs after each dilution change.
Project description:Transcriptional profiles of Escherichia coli MG1655 in mixed culture with Pseudomonas aeruginosa PAO1 showed a number of E. coli genes to be upregulated including purA-F and other genes associated with purine synthesis. In contrast, genes associated with pyrimidine synthesis were unaffected. Competition experiments in both planktonic and biofilm cultures, using three purine synthesis mutants, purD, purH, and purT showed little difference in E. coli survival from the parent strain. As purines are components of the cell signals, cAMP and c-di-GMP, we conducted competition experiments with E. coli mutants lacking adenylate cyclase (cyaA), cAMP phosphodiesterase (cpdA), and the catabolite receptor protein (crp), as well as ydeH, an uncharacterized gene that has been associated with c-di-GMP synthesis. Survival of the cyaA and crp mutants during co-culture were significantly less than the parent strain. Supplementation of the media with 1mM cAMP could restore survival of the cyaA mutant but not the crp mutant. In contrast, survival of the cpdA mutant was similar to the parent strain. Survival of the ydeH mutant was moderately less than the parent, suggesting that cAMP has more impact on E. coli mixed culture growth than c-di-GMP. Addition of 1 mM indole restored the survival of both the cyaA and crp mutations. Mutants in genes for tryptophan synthesis (trpE) and indole production (tnaA) showed a loss of competition and recovery through indole supplementation, comparable to the cyaA and crp mutants. Overall, these results suggest indole and cAMP as major contributing factors to E. coli growth in mixed culture. E. coli MG1655 and P. aeruginosa PAO1 were grown in a minimal defined medium containing N-acetyl glucosamine, overnight at 37C to an OD of 1.5, and then inoculated in fresh media at an OD of 0.001 and grown in pure or mixed culture for 4-5 hours to a final OD of 0.5. RNA was extracted, purified, reverse transcribed to cDNA and then analyzed on E. coli and P. aeruginosa chips from Affymetrix. Expression profiles of mixed culture-grown organisms were compared to pure culture E. coli and P. aeruginosa grown on the same defined medium.
Project description:E. coli isolates from different CF patients demonstrate increased growth rate when grown with glycerol, a major component of fecal fat, as the sole carbon source compared to E. coli from healthy controls. CF and control E. coli isolates have differential gene expression when grown in minimal media with glycerol as the sole carbon source. While CF isolates display a growth promoting transcriptional profile, control isolates engage stress and stationary phase programs, which likely results in slower growth rates.