Stress Conditioned Early‐Stage Screening in Biocatalysis

ABSTRACT The selection of enzymes for use as catalysts in chemical processes is typically carried out under optimal buffered conditions. However, under industrial conditions, at large scale, the environment usually includes pH gradients, oxygen limitation, interfacial deactivation, and high substrate or product concentrations. As a result, enzymes that perform well during initial laboratory screening often fail to maintain performance in large‐scale bioreactors. In this perspective, we propose the integration of process‐relevant stress conditions into the early stages of enzyme screening. We outline a framework in which parameters such as total turnover number (TTN) under stress, cofactor coupling efficiency, and solvent induced unfolding thresholds are measured alongside activity. These can be implemented in high‐throughput formats with minimal methodological change. We also present recent experimental studies where similar approaches have been used, although not always explicitly framed as stress‐based screening. The goal is to better align enzyme selection with real process demands, reducing uncertainty in early‐stage development. By shifting stress factors from test conditions to reportable and reproducible selection pressure, screening outcomes can be more predictive, and the overall efficiency of biocatalyst development for scale‐up can be improved.