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:The overexpression and purification of membrane proteins to high purity and homogeneity is a challenging task. Over time, several strains have been developed that decrease the toxic side-effects and thus result in higher bio mass and protein yield. However, two major contaminants have been identified in membrane protein preparations from E. coli: the outer membrane porin OmpF and AcrB, which is part of a tripartite efflux pump. Both proteins crystallise from low concentrations and diverse conditions, which make them a major problem, especially in membrane protein crystallography. In this study, we present a C41(DE3)-derived expression strains that is depleted of these two proteins.
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: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: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:Different genetic engineering strategies have been proposed to obtain E. coli strains that selectively consume xylose. In this study, a previously reported strategy for obtaining a xylose-selective strain in E. coli K12 was applied to E. coli BL21 (DE3). While this approach resulted in the expected xylose-selective phenotype, a low xylose consumption rate was recorded when the strain was grown on a mixture of xylose and glucose. To enhance xylose consumption, a variant of the transcriptional activator XylR was expressed. The resulting strain not only exhibited an improved capacity to consume xylose but also slightly recovered the ability to consume glucose. The aim of the microarray analysis was to identify the transcriptional changes associated with glucose assimilation in the BL21(DE3) derived xylose-selective strain.
