Transcriptome and membrane fatty acid analyses reveal different strategies for responding to permeating and non-permeating solutes in the bacterium Sphingomonas wittichii
| Autor: | Silvia K. Moreno-Forero, Hermann J. Heipieper, David R. Johnson, Edith Coronado, Jan Roelof van der Meer |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Microbiology (medical)
Cell Membrane Permeability Sodium lcsh:QR1-502 chemistry.chemical_element Sodium Chloride Biology Sphingomonas Microbiology lcsh:Microbiology Polyethylene Glycols 03 medical and health sciences Bioremediation Oligonucleotide Array Sequence Analysis 030304 developmental biology chemistry.chemical_classification 0303 health sciences Strain (chemistry) 030306 microbiology Gene Expression Profiling Fatty Acids Water Fatty acid Gene Expression Regulation Bacterial biology.organism_classification Biochemistry chemistry Environmental chemistry Sphingomonas wittichii Soil water Transcriptome Bacteria Research Article |
| Zdroj: | BMC Microbiology, vol. 11, no. 1, pp. 250 BMC Microbiology, Vol 11, Iss 1, p 250 (2011) BMC Microbiology |
| Popis: | Background Sphingomonas wittichii strain RW1 can completely oxidize dibenzo-p-dioxins and dibenzofurans, which are persistent contaminants of soils and sediments. For successful application in soil bioremediation systems, strain RW1 must cope with fluctuations in water availability, or water potential. Thus far, however, little is known about the adaptive strategies used by Sphingomonas bacteria to respond to changes in water potential. To improve our understanding, strain RW1 was perturbed with either the cell-permeating solute sodium chloride or the non-permeating solute polyethylene glycol with a molecular weight of 8000 (PEG8000). These solutes are assumed to simulate the solute and matric components of the total water potential, respectively. The responses to these perturbations were then assessed and compared using a combination of growth assays, transcriptome profiling, and membrane fatty acid analyses. Results Under conditions producing a similar decrease in water potential but without effect on growth rate, there was only a limited shared response to perturbation with sodium chloride or PEG8000. This shared response included the increased expression of genes involved with trehalose and exopolysaccharide biosynthesis and the reduced expression of genes involved with flagella biosynthesis. Mostly, the responses to perturbation with sodium chloride or PEG8000 were very different. Only sodium chloride triggered the increased expression of two ECF-type RNA polymerase sigma factors and the differential expression of many genes involved with outer membrane and amino acid metabolism. In contrast, only PEG8000 triggered the increased expression of a heat shock-type RNA polymerase sigma factor along with many genes involved with protein turnover and repair. Membrane fatty acid analyses further corroborated these differences. The degree of saturation of membrane fatty acids increased after perturbation with sodium chloride but had the opposite effect and decreased after perturbation with PEG8000. Conclusions A combination of growth assays, transcriptome profiling, and membrane fatty acid analyses revealed that permeating and non-permeating solutes trigger different adaptive responses in strain RW1, suggesting these solutes affect cells in fundamentally different ways. Future work is now needed that connects these responses with the responses observed in more realistic scenarios of soil desiccation. |
| Databáze: | OpenAIRE |
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