KeywordsBacteria, metals, Cupriavidus, resistance, cuivre
In the bacterial world, different mechanisms of metal resistance have been described (complexation, efflux, reduction, mineral formation, etc.). In the Proteobacterium Cupriavidus metallidurans CH34, but also in other closely related bacteria, it is possible that the formation of Outer Membrane Vesicles (OMVs) constitutes another mechanism of metal resistance. Indeed, preliminary studies have indicated that these vesicles are produced in the presence of copper, contain high copper levels, and that these vesicles are enriched in copper resistance proteins. The aim of the PhD project is to understand the mechanism of OMV formation when the CH34 strain is exposed to metals, particularly copper. For that, proteomics and microscopy will be used to investigate OMVs purified by ultracentrifugation. Genes involved in OMV formation will be seeked in the bacterial genome. Knockout mutants of some of the genes involved will be elaborated and studied. Other related strains, like Cupriavidus necator B9, will also be examined in parallel.