Diversity of Pseudomonas plasmids: to what extent?

Results obtained in studies of the biology of Pseudomonas plasmids are presented here as a mini-review. These data indicate that plasmids are ubiquitous in Pseudomonas, but the frequency of their occurrence varies greatly in particular species, or groups of species and in different microbial habitats. Some species of Pseudomonas, for instance P. aeruginosa, possess great diversity of plasmids both from the viewpoint of their incompatibility properties and their ability to endow bacteria with additional features such as resistance to antibiotics or heavy metals, degradation of xenobiotics or inhibition of phage development.