Metabolic Engineering of Pseudomonas

Summary The nonpathogenic soil bacterium Pseudomonas putida has become the cell factory of choice for a range of industrial applications. The natural lifestyle of this species, evolved to counteract harsh environmental conditions and physicochemical stress, is tied to a particular metabolic architecture that favors catabolic formation of reducing equivalents when cells grow on sugars. These built-in metabolic properties of P. putida have been exploited owing to an expanding synthetic biology toolbox for gene and genome edition. In this chapter, we discuss the value of Pseudomonas species (and, in particular, of P. putida strain KT2440) as a host for metabolic engineering. Importance Bacteria from the genus Pseudomonas are naturally endowed with phenotypic features that make them particularly attractive for bioprocesses, such as a very high level of resistance to stressful conditions. Such properties, together with a very rich metabolism that can be repurposed for the production of chemicals and polymers that would be very difficult (or even impossible) to produce efficiently in other hosts, make Pseudomonas the strongest candidate as alternative microbial platforms. The plethora of different products that have been produced in Pseudomonas (and, in particular, in the type strain P. putida KT2440 and its derivatives) bears witness of the industrial value of these bacteria. The availability of an ever-expanding toolbox is rendering the molecular and metabolic taming of these species easier, enabling metabolic engineers to access novel products through the implementation of synthetic pathways and biochemical reactions.