The heavy reliance of the chemical industry on petroleum for the production of fuels, solvents, and various materials is a major contributor to the alarming levels of environmental pollution caused by human activity and continued industrialization. The production of these compounds using bio-based methods offers potential solutions to environmental challenges such as climate change and pollution. However, the toxicity of these compounds to microorganisms commonly used in biotechnology is a major obstacle to effective bio-production techniques, which in turn hinders the competitiveness of biotechnological production compared to fossil-based bulk chemicals.
Addressing this challenge, the PROSPER project aims to demonstrate the bio-based synthesis of hydrophobic aromatic chemicals, with a primary focus on overcoming tolerance limitations during production. Within the scope of PROSPER, this project concentrates on enhancing production tolerance of solvents through engineering and evolution of robust producer strains. To achieve this, diverse strategies are used to establish a connection between microbial growth and solvent production.
One approach involves integrating the production pathway and rerouting the central metabolism through this pathway to stabilize the production phenotype. Another strategy utilizes solvent-sensing regulators, such as ttgVW, in conjunction with selection genes like essential genes or antibiotic-resistant markers to regulate growth based on solvent levels. In this context, we identified potential candidate genes. Once this coupling is established, adaptive laboratory evolution will be implemented to cultivate producer strains and improve their tolerance to the production of solvents. This process aims to identify key mutations responsible for enhanced tolerance against the internal production of solvents, rather than their external addition as is traditionally done. Our research will not only contributes to the development of robust Pseudomonas taiwanensis chassis strains but also will advances our understanding of solvent tolerance in Pseudomonas species.