Project description:The need for Ca2+ in the inactivation of bacteriophage phi X174 by lipopolysaccharide from Escherichia coli C was confirmed. Ca2+ could be replaced almost completely by Na+, but the concentration of Na+ needed was greater by more than an order of magnitude. Other bivalent ions caused inactivation in the same way as Ca2+, and the degree of inactivation varied according to the ion. At 50% inactivation of bacteriophage, the relation between the concentrations of NaCl and of bivalent or tervalent ions (Mx+) fitted the conception that NaCl was neutralizing electrostatic repulsion between virus and lipopolysaccharide by an ionic-strength effect: that is, log[Mx+] varies inversely with square root[NaCl]. The variation in effect of bi- and ter-valent ions and the low concentration needed show that this is not an ionic-strength effect but likely to involve binding to more than one site.
Project description:Escherichia coli (E. coli) amine oxidase (ECAO) encoded by tynA gene has been one of the model enzymes to study the mechanism of oxidative deamination of amines to the corresponding aldehydes by amine oxidases. The biological roles of ECAO have been less addressed. Therefore we have constructed a gene deletion Escherichia coli K-12 strain, E. coli tynA-, and used the microarray technique to address its function by comparing the total RNA gene expression to the one of the wt. Our results suggest that tynA is a reserve gene for stringent environmental conditions and its gene product ECAO a growth advantage compared to other bacteria due to H2O2 production. Overall design: The effect of deleting the expression of E. Coli amine oxidase by deleting tynA gene to the expression of other genes was done by comparing the knock out strain to wild type strain in different time points.
Project description:This SuperSeries is composed of the following subset Series: GSE12877: Transcriptional profiling of Escherichia coli after addition of CO-RMs to aerobically growing cells GSE12878: Transcriptional profiling of Escherichia coli after addition of CO-RMs to anaerobically growing cells Refer to individual Series
Project description:We report the effect of oxygenation state in lactose grown escherichia coli producing recombinant proteins. To shed more light on the mechanistic correlation between the uptake of lactose and dissolved oxygen, a comprehensive study has been undertaken with the E. coli BL21 (DE3) strain. Differences in consumption pattern of lactose, metabolites, biomass and product formation due to aerobiosis have been investigated. Transcriptomic profiling of metabolic changes due to aerobic process and microaerobic process during protein formation phase has been studied and the results provide a deeper understanding of protein production in E. coli BL21 (DE3) strains with lactose based promoter expression systems.This study also provides a scientific understanding of escherichia coli metabolism upon oxygen fluctuations. Overall design: Analysing the transcriptome of Escherichia culture grown in presence of lactose and also in different oxygenation of culture
Project description:Nucleic Acid Sequencing for the study of division induced double strand breaks in the terminus region of Escherichia coli cells lacking RecBCD DNA repair enzymes.
Project description:The intention of this study is to analyse the effect of antibiotics on the gene expression of Escherichia coli. Shaking-flask cultivations of Escherichia coli K12GFP-UTL2 were carried out with a medium containing nalidixic acid. Cultures with antibiotic-free medium, which were run in an identical way, served as reference. Samples were taken at different times during the cultivations, the RNA was isolated and hybridised on whole genome yeast microarrays. Keywords: Influence of toxins on gene expression in E. coli Overall design: A timeserial experiment of the influence of nalidixic acid on the gene expression in Escherichia coli was performed. Effects of the growth curve were eliminated by bionformatic methods.
Project description:This SuperSeries is composed of the following subset Series: GSE41936: Rho and NusG suppress pervasive antisense transcription in Escherichia coli [ChIP-chip]. GSE41938: Rho and NusG suppress pervasive antisense transcription in Escherichia coli [tiling array]. GSE41939: Rho and NusG suppress pervasive antisense transcription in Escherichia coli [RNA-seq]. Refer to individual Series
Project description:Transcription profile of Escherichia coli cells in biofilms under static batch culture was compared to that of E. coli cells in planktonic cultures. Both E. coli biofilm and planktonic cultures were cultivated for 18 h in 10% Luria-Bertani broth at room temperature (20 degree Celsius). Biofilms were grown in static batch culture in petri dishes. Both planktonic culture and biofilms were homogenized and run through a separated protocol. Overall design: Two condition experiments: E. coli biofilm vs E. coli planktonic cultures. Two biological replicates with independently grown and harvested biofilms or planktonic cultures. Each biological replicate has two technical replicates of hybridization on microarray slides. Each slide has three built-in replicates for each probe.