Generating Improved Amylase Enzymes by Directed Evolution

摘要

Amylase enzymes have many industrial applications, such as food processing and biofuel production. Because of the economic importance of this enzyme, there is great interest in developing amylases with higher activity to reduce the overall costs associated with these commercial processes. We employed a directed evolution strategy to develop highly active amylolytic enzymes. Pools of modified barley low pl amylase genes were generated by using PCR mutagenesis and DNA shuffling protocols. Libraries were created by cloning these mutant genes into an E. coli expression vector that directed the secretion of amylase into growth media containing starch. Clones with higher amylase activity were isolated based on the ability of the enzymes to digest the starch substrate.