Metabolic Profiling of Escherichia coli-based Cell-Free Expression Systems for Process Optimization.

Biotechnology has transformed the production of various chemicals and pharmaceuticals due to its efficient and selective processes, but it is inherently limited by its use of live cells as "biocatalysts." Cell-free expression (CFE) systems, which use a protein lysate isolated from whole cells, have the potential to overcome these challenges and broaden the scope of biomanufacturing. Implementation of CFE systems at scale will require determining clear markers of lysate activity and developing supplementation approaches that compensate for potential variability across batches and experimental protocols. Towards this goal, we use metabolomics to relate lysate preparation and performance to metabolic activity. We show that lysate processing affects the metabolite makeup of lysates, and that lysate metabolite levels change over the course of a CFE reaction regardless of whether a target compound is produced. Finally, we use this information to develop ways to standardize lysate activity and to design an improved CFE system.