PrePhage Chemostat
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ABSTRACT:
PROVIDER: PRJNA1121201 | ENA |
REPOSITORIES: ENA
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Project description:Background Microorganisms adapt their transcriptome by integrating multiple chemical and physical signals from their environment. Shake-flask cultivation does not allow precise manipulation of individual culture parameters and therefore precludes a quantitative analysis of the (combinatorial) influence of these parameters on transcriptional regulation. Steady-state chemostat cultures, which do enable accurate control, measurement and manipulation of individual cultivation parameters (e.g. specific growth rate, temperature, identity of the growth-limiting nutrient) appear to provide a promising experimental platform for such a combinatorial analysis. Results A microarray compendium of 170 steady-state chemostat cultures of the yeast Saccharomyces cerevisiae is presented and analyzed. The 170 microarrays encompass 55 unique conditions, which can be characterized by the combined settings of 10 different cultivation parameters. By applying a regression model to assess the impact of (combinations of) cultivation parameters on the transcriptome, most S. cerevisiae genes were shown to be influenced by multiple cultivation parameters, and in many cases by combinatorial effects of cultivation parameters. The inclusion of these combinatorial effects in the regression model led to higher explained variance of the gene expression patterns and resulted in higher function enrichment in subsequent analysis. We further demonstrate the usefulness of the compendium and regression analysis for interpretation of shake-flask-based transcriptome studies and for guiding functional analysis of (uncharacterized) genes and pathways. Conclusions Modeling the combinatorial effects of environmental parameters on the transcriptome is crucial for understanding transcriptional regulation. Chemostat cultivation offers a powerful tool for such an approach. Keywords: chemostat steady state samples
2009-02-05 | GSE11452 | GEO
Project description:M. smegmatis grown on cholesterol or glycerol in continous culture at a dilution rate of 0.01 h-1. Two-condition experiment, cholesterol chemostat vs. glycerol chemostat. Biological replicates: 4, two dye swaps
2016-07-03 | E-GEOD-71818 | biostudies-arrayexpress
Project description:We developed and validated a small-footprint array of miniature chemostats built from readily available parts for low cost. Physiological and experimental evolution results were similar to larger volume chemostats. The ministat array provides a compact, inexpensive, and accessible platform for traditional chemostat experiments, functional genomics, and chemical screening applications.
2012-12-21 | GSE36691 | GEO
Project description:The goal of this study was to study this interaction by analyzing genome-wide transcriptional responses to four different nutrient-limitation regimes under aerobic and anaerobic conditions in chemostat cultures of S. cerevisiae. This ‘two-dimensional’ approach resulted in a new, robust set of ‘anaerobic’ and ‘aerobic’ signature transcripts for S. cerevisiae, as well as to a refinement of previous reports on nutrient-responsive genes. Moreover, the identification of genes regulated both by nutrient and oxygen availability provided new insight in cross-regulated network and hierarchy in the control of gene expression. Keywords = S. cerevisiae Keywords = oxygen availability Keywords = anaerobiosis Keywords = chemostat Keywords = transcriptome Keywords = nutrient limitation Keywords = carbon Keywords = nitrogen Keywords = sulfur Keywords = phosphorus. Keywords: other
2004-09-03 | GSE1723 | GEO
Project description:Escherichia coli strains MG1655 and an isogenic norR::Tn5 mutant were grown in a New Brunswick Scientific Bioflow III Biofermentor under continuous culture (chemostat) conditions. Cells were grown in defined media containing 54 mM glycerol as the sole and limiting source of energy and carbon. The working volume was 1 litre, and the dilution rate 0.1 h-1. In order to establish anaerobic growth, nitrogen was sparged through the chemostat medium prior to inoculation and throughout the course of the experiment at a rate of 0.2 l/min. No dissolved oxygen was detectable using the OxyProbe. Sodium fumarate was added at a final concentration of 50 mM to act as a terminal electron acceptor. Cells were grown as above to steady-state, At steady-state, NOC-5 and NOC-7 were added to the chemostat culture and to the nutrient feed at a final concentration of 10 uM of each. Samples were taken after a period of 5 min exposure to NOC for subsequent analysis using microarrays. Cells were harvested directly into RNA Protect (Qiagen) to stabilize RNA, and total RNA was purified using Qiagen’s RNeasy Mini kit as recommended by the suppliers. Equal quantities of RNA from Wild type and norR::Tn5 cultures were labelled using nucleotide analogues of dCTP containing either Cy3 or Cy5 fluorescent dyes. The average signal intensity and local background correction were obtained using a commercially available software package from Biodiscovery, Inc (Imagene, version 4.0 and GeneSight, version 3.5). The mean values from each channel were log2 transformed and normalised using the Lowess method to remove intensity-dependent effects in the log2(ratios) values. The Cy3/Cy5 fluorescent ratios were calculated from the normalized values Keywords: Mutant Comparison, stress response, nitric oxide, NorR, chemostat, continuous culture
2006-09-01 | GSE5084 | GEO
Project description:Aspergillus fumigatus was cultured in a chemostat for 12.5 hours, and switched to hypoxia (0.2% oxygen). Samples were collected at the beginning of the experiment, before the switch to hypoxia, and 2, 6, 12 and 24 hours after the switch. RNA was extracted and microarrays performed to compare each time point to the time the experiment was switched. There are 3 biological replicates and 2 technical replicates.
2012-03-01 | E-MEXP-3251 | biostudies-arrayexpress
Project description:Escherichia coli strain MG1655 was grown in a New Brunswick Scientific Bioflow III Biofermentor under continuous culture (chemostat) conditions. Cells were grown in defined media containing 54 mM glycerol as the sole and limiting source of energy and carbon. The working volume was 1 litre, and the dilution rate 0.1 h-1. In order to establish anaerobic growth, nitrogen was sparged through the chemostat medium prior to inoculation and throughout the course of the experiment at a rate of 0.2 l/min. No dissolved oxygen was detectable using the OxyProbe. Sodium fumarate was added to anaerobic medium at a final concentration of 50 mM to act as a terminal electron acceptor. Cells were grown as above to steady-state, At steady-state, NOC-5 and NOC-7 were added to the chemostat culture and to the nutrient feed at a final concentration of 10 uM of each, unless otherwise stated. Samples were taken immediately prior to the addition of NOCs and after a period of 5 min exposure to NOC for subsequent analysis using microarrays. Cells were harvested directly into RNA Protect (Qiagen) to stabilize RNA, and total RNA was purified using Qiagen’s RNeasy Mini kit as recommended by the suppliers. Equal quantities of RNA from control and NOC-supplemented cultures were labelled using nucleotide analogues of dCTP containing either Cy3 or Cy5 fluorescent dyes. The average signal intensity and local background correction were obtained using a commercially available software package from Biodiscovery, Inc (Imagene, version 4.0 and GeneSight, version 3.5). The mean values from each channel were log2 transformed and normalised using the Lowess method to remove intensity-dependent effects in the log2(ratios) values. The Cy3/Cy5 fluorescent ratios were calculated from the normalized values. Keywords: Stress Reponse, Continuous culture, Chemostat, NO, Nitric oxide
2006-09-01 | GSE5076 | GEO
Project description:Zinc is indispensable for the catalytic activity and structural stability of many proteins, and its deficiency can have severe consequences for microbial growth in natural and industrial environments. For example, Zn depletion in wort negatively affects beer fermentation and quality. Several studies have investigated yeast adaptation to low Zn supply, but were all performed in batch cultures, where specific growth rate depends on Zn availability. The transcriptional responses to growth-rate and Zn availability are then intertwined, which obscures result interpretation. In the present study, transcriptional responses of Saccharomyces cerevisiae to Zn availability were investigated at a fixed specific growth rate under Zn limitation and excess in chemostat culture. To investigate the context-dependency of this transcriptional response, yeast was grown under several chemostat regimes resulting in various carbon (glucose), nitrogen (ammonium) and oxygen supplies. A robust set of genes that responded consistently to Zn limitation was identified and enabled the definition of a Zn-specific Zap1 regulon comprising of 26 genes and characterized by a broader ZRE consensus (MHHAACCBYNMRGGT) than so far described. Most surprising was the Zn-dependent regulation of genes involved in storage carbohydrate metabolism. Their concerted down-regulation was physiologically relevant as revealed by a substantial decrease in glycogen and trehalose cellular content under Zn limitation. An unexpectedly large amount of genes were synergistically or antagonistically regulated by oxygen and Zn availability. This combinatorial regulation suggested a more prominent involvement of Zn in mitochondrial biogenesis and function than hitherto identified Keywords: Chemostat based transcriptome analysis
2007-10-16 | GSE8089 | GEO