Pseudomonas putida is a ubiquitous rhizosphere saprophytic bacterium and soil colonizer that belongs to the wide group of fluorescent Pseudomonas species. P. putida strain KT2440, the best-characterized member of the group, became a model laboratory species that attracted considerable attention as a cell host for synthetic biology and metabolic engineering due to its remarkable and versatile metabolism, which has evolved to withstand harsh environmental conditions and physicochemical stress. This species has also retained the ability to survive and thrive in natural soil environments. P. putida mt-2 and other isolates have been recognized and used as agents for bioremediation due to their ability to grow on complex substrates, including aromatic compounds (e.g., toluene and xylenes). The absence of pathogenic determinants is another key feature of strain KT2440 that facilitated its adoption for both fundamental and applied research in microbiology.