Stress response of Cupriavidus metallidurans strains
ABSTRACT: Response of Cupriavidus metallidurans CH34, AE104 and delta zupT mutant to Zn/EDTA stress In this study 3 different treatments were performed to acquire expression profiles of the total genome of Cupriavidus metallidurans
Project description:Response of Cupriavidus metallidurans AE104(delta zupT) mutant to Zn/EDTA stress In this study 2 different treatments were performed to acquire expression profiles of the total genome of Cupriavidus metallidurans
Project description:Response of Cupriavidus metallidurans CH34 to cisplatin, Pt(IV)chloride and Au-NP In this study 7 different treatments were performed (first 2 as 3 replicates) to acquire expression profiles of the total genome of Cupriavidus metallidurans
Project description:Response of Cupriavidus metallidurans CH34 to NaAuCl4, Au(I)-thiomalate, Au(I)-thiosulfate, KAuCN, (KCN as control) In this study 10 different treatments were performed (first 7 as 3 replicates) to acquire expression profiles of the total genome of Cupriavidus metallidurans
Project description:Background: The high number of heavy metal resistance genes in the soil bacterium Cupriavidus metallidurans CH34 makes it an interesting model organism to study microbial responses to heavy metals. Results: In this study the transcriptional response of this bacterium was measured after challenging it to a wide range of sub-lethal concentrations of various essential or toxic metals. Considering the global transcriptional responses for each challenge as well as by identifying the overlap in upregulated genes between different metal responses, the sixteen metals could be clustered in three different groups. Additionally, next to the assessment of the transcriptional response of already known metal resistance genes, new metal response gene clusters were identified. The majority of the metal response loci showed similar expression profiles when cells were exposed to different metals, suggesting complex cross-talk at transcriptional level between the different metal responses. The highly redundant nature of these metal resistant regions – illustrated by the large number of paralogous genes – combined with the phylogenetic distribution of these metal response regions within evolutionary related and other metal resistant bacteria, provides important insights on the recent evolution of this naturally soil dwelling bacterium towards a highly metal-resistant strain found in harsh and anthropogenic environments. Conclusions: The metal-resistant soil bacterium Cupriavidus metallidurans CH34 displays myriads of gene expression patterns when exposed to a wide range of heavy metals at non-lethal concentrations. The interplay between the different gene expression clusters points towards a complex cross-regulated regulatory network governing heavy metal resistance in C. metallidurans CH34. Keywords: Cupriavidus metallidurans CH34, transcriptional regulation, heavy metal resistance Two-condition experiments. Comparing samples after induction with heavy metals versus non-induced samples. Biological duplicate or triplicate. Each array contains 3 or 4 technical replicates.
Project description:The physiological and transcriptomic response of the metal resistant bacterium Cupriavidus metallidurans strain CH34 in response to stable (non-radioactive) strontium ions (Sr) was investigated. C. metallidurans CH34 could survive and proliferate in the presence of relatively high concentrations of SrCl2 (D10 is 70mM, MIC is 120 mM). Precipitation of Sr as strontium carbonate was observed in the culture during aerobic growth of CH34 in the presence of 60 mM SrCl2. To identify the cellular mechanisms involved in the bioprecipitation process, gene expression in the cells was analyzed after short-time (30 min) exposure to low (5 mM) and high (60 mM) concentrations of SrCl2. The transcription of the gene clusters annotated as hmyFCBA and czcCBADRS, coding for ion efflux pumps, was significantly induced following exposure to Sr, and not with Ca. There were also significant changes is the transcription of the genes encoding TctCBA proteins involved in citrate uptake and two hypothetical porin coding genes following exposure Sr and Ca. These results highlight a specific molecular response of bacterium Cupriavidus metallidurans CH34 to Sr, including the identification of putative Sr specific efflux pumps, and thus the potential of this bacterium to distinguish Sr from Ca. These findings will help to better understand natural Sr (and Ca) microbial weathering or mineralization processes in the environment, and could be of interest for bioremediation or bioprocessing of (radioactive) Sr-containing water, soil or waste. Two-condition experiments. Comparing samples after induction with metals (Sr, Ca) versus non-induced samples. Biological triplicate. Each array contains 3 technical replicates.
Project description:Zinc is a central player in the metalloproteomes of prokaryotes and eukaryotes. We used a top-down quantitative proteomic approach to reveal the repository of the zinc pools in the proteobacterium Cupriavidus metallidurans. About 60% of the theoretical proteome of C. metallidurans were identified, quantified, and compared between a ΔzupT mutant defect in zinc allocation and its parent strain. In both strains, the number of zinc-binding proteins and their binding sites exceeded that of the zinc ions per cell, indicating that the totality of the zinc proteome provides empty binding sites for incoming zinc ions. This zinc repository plays a central role in zinc homeostasis in C. metallidurans and probably also in other organisms.
Project description:Different Cupriavidus metallidurans strains isolated from metal-contaminated and other anthropogenic environments were genotypically and phenotypically compared with C. metallidurans type strain CH34. The latter is well-studied for its resistance to a wide range of metals, which is carried for a substantial part by its two megaplasmids pMOL28 and pMOL30. Comparative genomic hybridization (CGH) indicated that the extensive arsenal of determinants involved in metal resistance was well conserved among the different C. metallidurans strains. Contrary, the mobile genetic elements identified in type strain CH34 were not present in all strains but clearly showed a pattern, although, not directly related to a particular biotope nor location (geographical). One group of strains carried almost all mobile genetic elements, while these were much less abundant in the second group. This occurrence was also reflected in their ability to degrade toluene and grow autotrophically on hydrogen gas and carbon dioxide, which are two traits linked to separate genomic islands of the Tn4371-family. In addition, the clear pattern of genomic islands distribution allowed to identify new putative genomic islands on chromosome 1 and 2 of C. metallidurans CH34. Metal resistance determinants are shared by all C. metallidurans strains and their occurrence is apparently irrespective of the strain's isolation type and place. Cupriavidus metallidurans strains do display substantial differences in the diversity and size of their mobile gene pool, which may be extensive in some (including the type strain) while marginal in others. Comparative genome hybridization experiments. Comparing genomic DNA samples of different strains with a common reference strain (CH34).
Project description:Response of Cupriavidus metallidurans AE104 and delta zur mutant to Zn stress Overall design: In this study Zn-treatment was performed to acquire expression profiles of the total genome of Cupriavidus metallidurans