Directed and adaptive evolution approaches for strain engineering

Blending pathway engineering with directed evolution and adaptive strain engineering enables a powerful approach for rapid metabolic engineering. This talk will highlight how the evolution of small parts, enzymes, pathways, and whole cells can rapidly accomplish metabolic engineering goals. First, this talk will discuss recent advances in the evolution of metabolic phenotypes including xylose catabolism, lipid overproduction, aromatic product overproduction, and riboflavin overproduction in the yeasts Saccharomyces cerevisiae and Yarrowia lipolytica. Second, this talk will discuss recent advances in developing an in vivo mutagenesis approach in yeast by synthetically optimizing the retrotransposon Ty1. This approach is used in the directed evolution of global transcriptional regulators, single enzymes, and multi-gene pathways. In each case described here, we obtain rapid and significant improvements in performance. Finally, we demonstrate how this approach can be coupled with microdroplet technologies to enable rapid screening and selection of pathway variants, thus speeding the process of metabolic phenotype improvement.