RNA-seq of E. coli BL21 (DE3) Evolved in High pH (pH = 9) Terrific Broth Media
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ABSTRACT:
INSTRUMENT(S): NextSeq 500
ORGANISM(S): Escherichia coli BL21(DE3)
SUBMITTER: Suraj Mital
PROVIDER: E-MTAB-12337 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
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.
2023-10-31 | E-MTAB-12334 | biostudies-arrayexpress
Project description:Gene expression profiles of Escherichia coli K-12 W3110 were compared as a function of steady-state external pH. Cultures were grown with aeration to an optical density at 600 nm of 0.3 in potassium-modified Luria-Bertani medium buffered at pH 5.0, 7.0, and 8.7. For each of the three pH conditions, cDNA from RNA of five independent cultures was hybridized to Affymetrix E. coli arrays. Analysis of variance with a significance level of 0.001 resulted in 98% power to detect genes showing a twofold difference in expression. Normalized expression indices were calculated for each gene and intergenic region (IG). Differential expression among the three pH classes was observed for 763 genes and 353 IGs. Hierarchical clustering yielded six well-defined clusters of pH profiles, designated Acid High (highest expression at pH 5.0), Acid Low (lowest expression at pH 5.0), Base High (highest at pH 8.7), Base Low (lowest at pH 8.7), Neutral High (highest at pH 7.0, lower in acid or base), and Neutral Low (lowest at pH 7.0, higher at both pH extremes). Flagellar and chemotaxis genes were repressed at pH 8.7 (Base Low cluster), where the cell's transmembrane proton potential is diminished by the maintenance of an inverted pH gradient. High pH also repressed the proton pumps cytochrome o (cyo) and NADH dehydrogenases I and II. By contrast, the proton-importing ATP synthase F1Fo and the microaerophilic cytochrome d (cyd), which minimizes proton export, were induced at pH 8.7. These observations are consistent with a model in which high pH represses synthesis of flagella, which expend proton motive force, while stepping up electron transport and ATPase components that keep protons inside the cell. Acid-induced genes, on the other hand, were coinduced by conditions associated with increased metabolic rate, such as oxidative stress. All six pH-dependent clusters included envelope and periplasmic proteins, which directly experience external pH. Overall, this study showed that (i) low pH accelerates acid consumption and proton export, while coinducing oxidative stress and heat shock regulons; (ii) high pH accelerates proton import, while repressing the energy-expensive flagellar and chemotaxis regulons; and (iii) pH differentially regulates a large number of periplasmic and envelope proteins. Experiment Overall Design: Gene expression profiles of Escherichia coli K-12 W3110 were compared as a function of steady-state external pH. Overnight cultures were diluted 1:1000 in potassium-modified Luria-Bertani medium (LBK) buffered with 50 mM HOMOPIPES at pH 5.0, pH 7.0, and pH 8.7. Bacteria were cultured in baffled flasks (less than 10% volume filled) with rotation at 240 rpm, incubated at 37°C to an optical density at 600 nm of 0.3. For each of the three pH conditions, RNA was isolated from five independent cultures. Labeled cDNA was hybridized to Affymetrix antisense arrays according to standard procedures. To analyze the expression levels, Dchip software was used to generate model-based expression indices normalized to sample pH 7 replicate 1. ANOVA was used to identify genes with sitnificant expression differences among the three pH classes (p = 0.001). For genes showing significant differences, the Log2 expression ratios were determined for each pair of pH classes, and significance was determined by Tukey's test (p = 0.001).
2007-09-21 | E-GEOD-4511 | biostudies-arrayexpress
Project description:In Escherichia coli, pH-dependent gene expression varies with oxygen level. Anaerobic pH-dependent expression ratios were analyzed and compared to the published analysis of aerated cultures (Maurer et al, 2005). E. coli K-12 strain W3110 was cultured in closed tubes containing LBK broth buffered at pH 5.7, pH 7.0, and pH 8.5. Gene expression profiles were obtained by cDNA hybridization to Affymetrix arrays. pH-dependent expression was seen for 1,394 genes, of which 1,002 show no pH dependence under aeration. Four intergenic regions containing regulatory sRNAs were up-regulated by acid anaerobically (ryeA, csrB, gadY, rybC) and one sRNA (ryhA) by acid with aeration. Acid and anaerobiosis co-regulated the gad regulon; drug transporters (mdtEF, mdtL); catabolism of sugar derivatives whose fermentation minimized acid production; and all hydrogenases (hya, hyb, hyc, hyf, hyp). The hydrogenases however were up-regulated at high pH under aeration (observed by real-time PCR). Acid with anaerobiosis down-regulated penicillin-binding proteins (dacACD, mreBC) and ribosome biosynthesis. Ribosome down-regulation may be caused by restriction of anaerobic metabolism at low pH. A core group of 236 genes showed similar pH response with or without aeration. Core genes up-regulated by acid included fimbriae (fimAC), periplasmic chaperones (hdeAB), cyclopropane fatty acid synthase (cfa), the â??constitutiveâ?? Na+/H+ antiporter (nhaB), and over thirty unidentified proteins. Core genes at high pH included maltodextrin transport (lamB, malEFGKMPQT), ATP synthase, and DNA repair (recA and mutL). Overall, pH and anaerobiosis co-regulated metabolism and transport so as to maximize alternative catabolic options while minimizing acidification or alkalinization of the cytoplasm. Experiment Overall Design: Gene expression profiles of Escherichia coli K-12 W3110 were compared as a function of steady-state external pH during growth without aeration. The experiment was designed for direct comparison with the pH profile under aerobic conditions reported previously (GSE4511). Non-aerated overnight cultures were diluted 1:1000 and incubated in closed tubes containing potassium-modified Luria-Bertani medium (LBK) buffered with 50 mM HOMOPIPES at pH 5.7, pH 7.0, and pH 8.5. Tubes were incubated at37°C with slow rotation (8 rpm) to an optical density at 600 nm of 0.2. For each of the three pH conditions, RNA was isolated from five independent cultures. Labeled cDNA was hybridized to Affymetrix antisense arrays according to standard procedures. To analyze the expression levels, Dchip software was used to generate model-based expression indices normalized to sample pH 7 replicate 1. ANOVA was used to identify genes with sitnificant expression differences among the three pH classes (p = 0.001). For genes showing significant differences, the Log2 expression ratios were determined for each pair of pH classes, and significance was determined by Tukey's test (p = 0.001).
2008-06-13 | E-GEOD-4556 | biostudies-arrayexpress
Project description:The RNA-induced silencing complex, comprising Argonaute and guide RNA, mediates RNA interference. Here we report the 3.2 Å crystal structure of Kluyveromyces Argonaute (KpAGO) fortuitously complexed with guide RNA originating from small-RNA duplexes autonomously loaded by recombinant KpAGO. Despite their diverse sequences, guide-RNA nucleotides 1-8 are positioned similarly, with sequence-independent contacts to bases, phosphates and 2'-hydroxyl groups pre-organizing the backbone of nucleotides 2-8 in a near-A-form conformation. Compared with prokaryotic Argonautes, KpAGO has numerous surface-exposed insertion segments, with a cluster of conserved insertions repositioning the N domain to enable full propagation of guide-target pairing. Compared with Argonautes in inactive conformations, KpAGO has a hydrogen-bond network that stabilizes an expanded and repositioned loop, which inserts an invariant glutamate into the catalytic pocket. Mutation results and analogies to Ribonuclease H indicate that insertion of this glutamate finger completes a universally conserved catalytic tetrad, thereby activating Argonaute for cleavage. Employ high-throughput sequencing of small RNAs extracted from soluble or crystalline K. polysporus Ago1(207-1251) that had been purified from E. coli
2012-05-14 | E-GEOD-37724 | biostudies-arrayexpress
Project description:The expression levels of uropathogenic E. coli (UPEC) UTI89 cells in YESCA broth with and without 4% dimehtyl sulfoxide (DMSO) and 2% ethanol (EtOH) were studied. To determine the up- or down-regulated expression profile in the presence of dimethyl sulfoxide (DMSO) and ethanol (EtOH), UPEC UTI89 were grown in YESCA broth with 4% dimethyl sulfoxide (DMSO) or 2% ethanol (EtOH) or no comound at 26°C with 200 rpm shaking for 24 hours were used for RNA extraction and hybridization on Affymetrix microarrays.
2012-02-15 | E-GEOD-35797 | biostudies-arrayexpress
Project description:The aim of this study is to investigate the changes of global gene expression in E. coli during a carbon source shift. Expression profiling of an evolved strain of E. coli K12 MG1655 grown in M9 minimal media supplemented with propylene glycol or glycerol. A six chip study under two separate culture conditions
2012-05-31 | E-GEOD-34631 | biostudies-arrayexpress
Project description:In Escherichia coli, pH-dependent gene expression varies with oxygen level. Anaerobic pH-dependent expression ratios were analyzed and compared to the published analysis of aerated cultures (Maurer et al, 2005). E. coli K-12 strain W3110 was cultured in closed tubes containing LBK broth buffered at pH 5.7, pH 7.0, and pH 8.5. Gene expression profiles were obtained by cDNA hybridization to Affymetrix arrays. pH-dependent expression was seen for 1,394 genes, of which 1,002 show no pH dependence under aeration. Four intergenic regions containing regulatory sRNAs were up-regulated by acid anaerobically (ryeA, csrB, gadY, rybC) and one sRNA (ryhA) by acid with aeration. Acid and anaerobiosis co-regulated the gad regulon; drug transporters (mdtEF, mdtL); catabolism of sugar derivatives whose fermentation minimized acid production; and all hydrogenases (hya, hyb, hyc, hyf, hyp). The hydrogenases however were up-regulated at high pH under aeration (observed by real-time PCR). Acid with anaerobiosis down-regulated penicillin-binding proteins (dacACD, mreBC) and ribosome biosynthesis. Ribosome down-regulation may be caused by restriction of anaerobic metabolism at low pH. A core group of 236 genes showed similar pH response with or without aeration. Core genes up-regulated by acid included fimbriae (fimAC), periplasmic chaperones (hdeAB), cyclopropane fatty acid synthase (cfa), the “constitutive” Na+/H+ antiporter (nhaB), and over thirty unidentified proteins. Core genes at high pH included maltodextrin transport (lamB, malEFGKMPQT), ATP synthase, and DNA repair (recA and mutL). Overall, pH and anaerobiosis co-regulated metabolism and transport so as to maximize alternative catabolic options while minimizing acidification or alkalinization of the cytoplasm. Keywords: Steady State
2006-10-01 | GSE4556 | GEO
Project description:Transcriptional profiles of uropathogenic Escherichia coli CFT073 exposed to cranberry-derived proanthocyanidins (PACs) were determined. Our results indicate that bacteria grown on media supplemented with PACs were iron-deprived. To our knowledge, this is the first time that PACs have been shown to induce a state of iron-limitation in this bacterium. Cultures of E. coli CFT073 were streaked onto LB agar plates and incubated (37°C, 24 h). A single colony was inoculated into 150 mL of LB broth. Three inoculated flasks contained LB broth alone (controls), and three inoculated flasks were supplemented with cranberry PACs (100 µg/mL). After incubation (37°C, 5 h, 200 rpm to mid-log growth phase), bacteria were harvested for RNA extraction.
2010-12-02 | E-GEOD-25745 | biostudies-arrayexpress
Project description:Metals at high concentrations can exert toxic effects on microorganisms. It has been widely reported that lowering environmental pH reduces effects of cadmium toxicity in bacteria. Understanding the effects of pH-mediated cadmium toxicity on bacteria would be useful for minimizing cadmium toxicity in the environment and gaining insight into the interactions between organic and inorganic components of life. Growth curve analysis confirmed that cadmium was less toxic to Escherichia coli at pH 5 than at pH 7 in M9 minimal salts medium. To better understand the cellular mechanisms by which lowering pH decreases cadmium toxicity, we used DNA microarrays to characterize global gene expression patterns in E. coli in response to cadmium exposure at moderately acidic (5) and neutral (7) values of pH. Higher expression of several stress response genes including hdeA, otsA, and yjbJ at pH 5 after only 5 minutes was observed and may suggest that acidic pH more rapidly induces genes that confer cadmium resistance. Genes involved in transport were more highly expressed at pH 7 than at pH 5 in the presence of cadmium. Of the genes that showed an interaction between pH and cadmium effects, 46% encoded hypothetical proteins, which may have novel functions involved in mitigating cadmium toxicity.
2008-08-21 | GSE12373 | GEO
Project description:The effect of an extracellular acid shift on gene expression profiles of Escherichia coli K-12 W3110 was observed using Affymetrix E. coli arrays. In order to maximize aeration and maintain logarithmic growth, the overnight culture (LBK broth medium) was diluted 500-fold into a 250-ml baffled flask containing 55 ml of 20mM HOMOPIPES buffered medium (pH 7.6). Cultures were grown to OD600=0.2. A shift to acid external pH was conducted by rapid addition of 840 µl 1M HCl, which lowered the pH of the medium to pH 5.5. For each of five biological replicates, 10-ml samples were taken at times 0, 1, 5, and 10 min post addition of HCl. Each sample was added to 1 ml 10% phenol-ethanol stop solution in <5 sec. For each sample, cDNA synthesized from total RNA was hybridized onto Affymetrix E. coli arrays. Model-based gene expression intensities were determined using GCOS software. Gene-by-gene temporal differential expression was analyzed as a mixed-effects model using polynomial time functions as fixed effects and flask variation as a random effect. Experiment Overall Design: Gene expression profiles of Escherichia coli K-12 W3110 were compared as a function of time versus change in external pH. Overnight cultures were diluted 1:500 in potassium-modified Luria-Bertani medium (LBK) buffered with 20 mM HOMOPIPES at 7.6. Bacteria were cultured in baffled flasks (less than 10% volume) with rotation at 225 rpm, incubated at 37°C to an optical density at 600 nm of 0.2. External pH was lowered to pH 5.5 by adding 840 µl of 1M HCl to 40 mls of culture within 5 seconds. Four samples were taken from each of five replicate cultures, corresponding to time 0 (before HCl addition),1, 5, and 10 min post HCl addition.
2008-04-07 | E-GEOD-4778 | biostudies-arrayexpress