TY - JOUR
T1 - Rhodobacter sphaeroides adaptation to high concentrations of cobalt ions requires energetic metabolism changes
AU - Volpicella, Mariateresa
AU - Costanza, Alessandra
AU - Palumbo, Orazio
AU - Italiano, Francesca
AU - Claudia, Leoni
AU - Placido, Antonio
AU - Picardi, Ernesto
AU - Carella, Massimo
AU - Trotta, Massimo
AU - Ceci, Luigi R.
PY - 2014
Y1 - 2014
N2 - Rhodobacter sphaeroides has for a long time been investigated for its adaptive capacities to different environmental and nutritional conditions, including presence of heavy metals, which make it a valuable model organism for understanding bacterial adaptation to metal stress conditions and future environmental applications, such as bioremediation of polluted sites. To further characterize the capability of R. sphaeroides to cope with high cobalt ion concentrations, we combined the selection of adaptive defective mutants, carried out by negative selection of transposon insertional libraries on 5 mM Co2+-enriched solid medium, with the analysis of growing capacities and transcriptome profiling of a selected mutant (R95). A comparative analysis of results from the mutant and wild-type strains clearly indicated that the adaptive ability of R. sphaeroides strongly relies on its ability to exploit any available energy-supplying metabolisms, being able to behave as photo- or chemotrophic microorganism. The selected R95 mutant, indeed, exhibits a severe down-expression of an ABC sugar transporter, which results nonpermissive for its growth in cobalt-enriched media under aerobic conditions. Interestingly, the defective expression of the transporter does not have dramatic effects on the growth ability of the mutant when cultivated under photosynthetic conditions.
AB - Rhodobacter sphaeroides has for a long time been investigated for its adaptive capacities to different environmental and nutritional conditions, including presence of heavy metals, which make it a valuable model organism for understanding bacterial adaptation to metal stress conditions and future environmental applications, such as bioremediation of polluted sites. To further characterize the capability of R. sphaeroides to cope with high cobalt ion concentrations, we combined the selection of adaptive defective mutants, carried out by negative selection of transposon insertional libraries on 5 mM Co2+-enriched solid medium, with the analysis of growing capacities and transcriptome profiling of a selected mutant (R95). A comparative analysis of results from the mutant and wild-type strains clearly indicated that the adaptive ability of R. sphaeroides strongly relies on its ability to exploit any available energy-supplying metabolisms, being able to behave as photo- or chemotrophic microorganism. The selected R95 mutant, indeed, exhibits a severe down-expression of an ABC sugar transporter, which results nonpermissive for its growth in cobalt-enriched media under aerobic conditions. Interestingly, the defective expression of the transporter does not have dramatic effects on the growth ability of the mutant when cultivated under photosynthetic conditions.
KW - Bioremediation
KW - Heavy metal stress
KW - Negative selection
KW - Rhodobacter sphaeroides
KW - Transcriptomics
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U2 - 10.1111/1574-6941.12303
DO - 10.1111/1574-6941.12303
M3 - Article
C2 - 24579873
AN - SCOPUS:84899928916
VL - 88
SP - 345
EP - 357
JO - FEMS Microbiology Ecology
JF - FEMS Microbiology Ecology
SN - 0168-6496
IS - 2
ER -