Position title: Chemical and Biological Engineering
- Brian Pfleger
Engineering Synthesis of Bacterial Natural Products
Pseudomonas putida is a promising bacterial host for the production of natural products, such as polyketide synthases (PKS) and nonribosomal peptide synthetases (NRPS). Many natural products are of great interest in medicine due to their antibiotic, immunosuppressant, or antitumor properties. There is a need for more cost-effective and renewable methods for producing natural products, especially those that have been recently discovered. P. putida is capable of expressing complex biosynthetic gene clusters, and its chromosome has high GC content, like most organisms that produce natural products. To unlock P. putida’s potential as a host for heterologous genes, researchers need a genetic toolbox consisting of plasmids, characterized promoters, and techniques for rapidly editing the genome. Previous reports have characterized constitutive and inducible promoters, broad host range origins, and genome-editing methods. Our lab has augmented these tools by improving the fold induction of an IPTG-inducible promoter system in P. putida and discovering that the copy numbers of broad host range origins are significantly higher in P. putida than in E. coli. Lastly, we developed a λRed/Cas9 recombineering method that enables efficient integration of double-stranded DNA into the chromosome of P. putida. Our lab plans to take advantage of these new tools to genetically engineer P. putida to produce non-native PKS’s and NRPS’s with properties of medical interest.