Transcriptomic differences between E. coli BL21 and K-12 MG1655 during n-heptanoic acid stress
Ontology highlight
ABSTRACT: Biosynthesis of carboxylic acids and fatty acids from renewable biomass is a key issue in biorefinery. However, their productivities are often limited due to various toxic effects of the products on the host organisms. Here, we have investigated the factors that influence tolerance of Escherichia coli to long chain carboxylic acid (e.g., n-heptanoic acid)-induced stress by using transcriptome analysis. The metabolic and genomic responses of E. coli BL21 and MG1655 strains with n-heptanoic acid indicated that acid stress is one of the major stresses, which might be generated by n-heptanoic acid in addition to the presumed solvent-like stress.
Project description:Transcription profiles in BL21, BL21/pOri1 and BL21/pOri2 were analysed using DNA microarray technology. BL21, BL21/pOri1 or BL21/pOri2 strains were cultured at chemostat status and harvested after the cultivation arrived steady status. Experiment Overall Design: BL21, BL21/pOri1 and BL21/pOri2 were cultured at the exponential growth status or at the same growth rate status, respectively. E. coli BL21, BL21/pOri1 and BL21/pOri2 RNAs were reverse-transcripted into cDNAs, The RNAs from the BL21, BL21/pOri1, BL21/pOri2 were labelled with biotin. The labelled cDNAs were mixed and then hybridized on the microarray slides. Experiments were repeated four times. Most of them have no significant difference comparing plasmid-carrying E. coli and plasmid-free E. coli
Project description:Transcriptional profiling of E. coli strain comparing control BL21 with recombineered HLT013. HLT013 strains was derived from BL21 and capable of producing thymidine.
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:Amino acid starvation during recombinant protein production (RPP) induces metabolic stress to cellular host which results in reduced productivity of the recombinant bioprocess. In present study, supplementation of amino acids in a chemically defined medium showed several folds increase in recombinant product titers in E. coli BL21 DE3 strain. To understand, the effect of amino acid supplementation in alleviating cellular stress during RPP a deep insight of cellular physiology must be studied. Here, we performed transcriptomic analysis of E. coli expressing a recombinant protein in two different conditions: with (5 mM of all 20 amino acids) as test and without supplementation of amino acids as control. RNA-seq data revealed downregulation of several genes associated with stress in test culture confirming the critical role of amino acids supplementation in improving RPP.
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: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.
Project description:Proteomic data from LC-MSMS of E. coli BL21 Gold grown in varying growth conditions, including in LB, M9, and spent mammalian cell media.
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.