Directed Evolution of Biocatalysts

Biocatalysis is the activity to synthesize chemicals using biological entities, in particular enzymes. Natural enzymes often need to be optimized before being used in industrial processes, and directed evolution is an approach that is well suited for the creation of these improved industrial biocatalysts. Directed evolution involves creating a library of mutant genes and then sorting them based on the associated phenotypes. Main library creation and sorting protocols are compared here, with an emphasis on semirational approaches to library creation and fast screening or pool selection techniques. Representative reports of improved catalytic activity, enzyme stability, and specificity are discussed. Finally, an insight is given on recent technological developments to make enzymes more suitable for biocatalysis. These new technologies could favor the switch of numerous processes from chemistry to biocatalysis soon.