An E-coli expression system for the extracellular secretion of barley alpha-amylase

Libraries of modified genes are often screened during the process of geneti cally engineering enzymes with specifically tailored activities. It is impo rtant, therefore, to create expression systems which allow for the rapid sc reening of many clones. We developed an Escherichia coli expression system which will secrete enzymes into the growth medium. We describe the first re ported expression of barley alpha -amylase in E. coli. The enzyme is secret ed onto solid media containing starch to produce easily visualized halos. I n addition, the enzyme is secreted into liquid media in an intact, active f orm.