The Purification of Cellulase and Hemicellulase Components from an Extreme Thermophile by the Cloning of Enzymes into E. coli

Abstract

The use of heat treatment to purify enzymes by selective denaturation and then by the subsequent precipitation of denatured protein is a simple, rapid, and well established procedure. Successful applications are limited to those few enzymes that possess a thermostability considerably higher than the majority of cell proteins. The introduction of thermostable enzymes into the protein population of a mesophile by cloning offers a clear opportunity to employ a heat-treatment method of purification to its full advantage (e.g., see references 1 and 2). In light of the difficulties involved in purifying bacterial cellulases, the cloning of some of the cellulase and hemicellulase genes of Caldocellum saccharolyticum into Escherichia coli has provided a welcome alternative procedure for obtaining pure enzymes.