Pseudomonads may benefit from their built-in characteristics when utilised as hosts. The host’s robustness is evidently becoming a central aspect in strain development in the face of increasingly demanding production processes and targeted chemistry. The Pseudomonas clade thus appears to provide an intriguing starting point to shed light on xenobiotic tolerance in the context of biotechnological applications such as plastics upcycling, aromatics production, and trans-metabolism. Most of these products are not natively synthesised by the host strain, thus confronting cells with novel and – in parts – harmful chemistry, as many hydrophobic and antibiotic products tend to corrupt enzyme or membrane integrity. This has likely contributed to the development of the soil bacterium Pseudomonas putida and its relatives into versatile microbial cell factories during the past few decades, enabling the biosynthesis of various compounds including secondary metabolites like rhamnolipids, terpenes, polyketides, and non-ribosomal peptides, organic acids, alcohols, and aromatics. We further highlight strategies for the identification of yet unknown tolerance-associated genes and their utilisation for engineering next-generation chassis and finally discuss effective measures for pathway fine-tuning to establish stable cell factories for the effective production of natural compounds and novel biochemicals.īacteria have evolved numerous strategies to alleviate chemical stress and members of the Pseudomonas clade are especially well-equipped with such traits.
In this article, we therefore discuss major resistance strategies of Pseudomonads along with approaches pursued for their targeted exploitation and engineering in a biotechnological context. Exploiting and engineering these features will be essential to support an effective production of natural compounds and new chemicals. Finally, toxic chemicals such as reactive aldehydes can be eliminated by oxidation and stress-induced damage can be recovered. Further, effective export machineries can prevent intracellular accumulation of diverse harmful compounds. A built-in cell envelope stress response enables fast adaptations that sustain membrane integrity under adverse conditions. Species of the Pseudomonas clade thus represent especially valuable chassis as they are endowed with multiple stress response mechanisms, which allow them to cope with a variety of harmful chemicals. However, the associated substrates and biosynthetic products often cause severe chemical stress to the bacterial hosts. Nowadays, advanced molecular genetic toolsets, enzyme engineering as well as the combinatorial use of biocatalysts, pathways, and circuits even bring new-to-nature compounds within reach. Biotechnological production in bacteria enables access to numerous valuable chemical compounds.