Project description:Heat-responsive and time-resolved changes in transcriptome of E. coli BL21(DE3) Experimentally mapped transcriptome structure of Escherichia coli BL21(DE3) by hybridizing total RNA (including RNA species <200 nt) to genome-wide high-density tiling arrays (60 mer probes tiled every 10 nt).
Project description:This study assessed the differential gene expression of C41(DE3) and C43(DE3) strains in comparison to their parental strain BL21(DE3), in the presence and absence of a prototypical protein expression vector with or without the inducer IPTG.
Project description:Deep-sequencing of the engineered production genes in five E coli production chassis strains (BL21(DE3), MG1655, TOP10, W and W3110) producing two case metabolic products, 2,3-butanediol and mevalonic acid
Project description:Whole genome sequencing was performed on E. coli BL21 (DE3) evolved at 25°C in pH 9 terrific broth media buffered with Tris-HCl (pH 9). The evolved E. coli was characterized and compared to the parent strain.
Project description:Experimentally mapped transcriptome structure of Escherichia coli BL21(DE3) by hybridizing total RNA (including RNA species <200 nt) to genome-wide high-density tiling arrays (60 mer probes tiled every 10 nt).
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.
Project description:In this study we have employed metabolomics approaches to understand the metabolic effects of producing enhanced green fluorescent protein (eGFP) as a recombinant protein in Escherichia coli cells. This metabolic burden analysis was performed against a number of recombinant expression systems and control strains and included: (i) standard transcriptional recombinant expression control system BL21(DE3) with the expression plasmid pET-eGFP, (ii) the recently developed dual transcriptional–translational recombinant expression control strain BL21(IL3), with pET-eGFP, (iii) BL21(DE3) with an empty expression plasmid pET, (iv) BL21(IL3) with an empty expression plasmid, and (v) BL21(DE3) without an expression plasmid; all strains were cultured under various induction conditions. The growth profiles of all strains together with the results gathered by the analysis of the Fourier transform infrared (FT-IR) spectroscopy data, identified IPTG-dependent induction as the dominant factor hampering cellular growth and metabolism, which was in general agreement with the findings of GC-MS analysis of cell extracts and media samples. In addition, the exposure of host cells to the synthetic inducer ligand, pyrimido[4,5-d] pyrimidine-2,4-diamine (PPDA), of the orthogonal riboswitch containing expression system (BL21(IL3)) did not display any detrimental effects, and its detected levels in all the samples were at similar levels, emphasising the inability of the cells to metabolise PPDA. The overall results obtained in this study suggested that although the BL21(DE3)-EGFP and BL21(IL3)-EGFP strains produced comparable levels of recombinant eGFP, the presence of the orthogonal riboswitch seemed to be moderating the metabolic burden of eGFP production in the cells enabling higher biomass yield, whilst providing a greater level of control over protein expression.
