The Selection of Optimum Media Formulations for Improved Expression of Recombinant Proteins In E. coli

Escherichia coli is routinely used for the production of recombinant proteins both for research purposes and for commercial applications. Despite the extensive amount of knowledge gathered about the synthesis and accumulation of heterologous proteins and the well established principals affecting the production of secondary metabolites, little attention has been paid to the effects of medium composition on the production of recombinant proteins. In the course of optimizing the production of various recombinant proteins, we found that the level of accumulation of a given protein was composition-dependent. Since the best formulation for a protein could not be determined solely on the basis of the class of protein, a simple screening technique was developed to rapidly identify the best available medium for any give recombinant protein. The screen was tested on six different recombinant proteins and shown to be an effective means of empirically determining the best medium. It was further observed that the medium composition affected the relative level of soluble protein that accumulated. These results suggested that a medium screen should be employed as a routine part of developing bacterial strains which produce recombinant proteins. The application of such a screen could aid in improving the recovery of recombinant proteins. Technical Bulletin – Athena Enzyme Systems Group Volume 2, January, 2001 Copyright © 2001, Athena Environmental Sciences, Inc. All rights reserved.