Interface‐Aware Design of Biocatalysis

Interfaces play a critical role in biocatalysis but are rarely considered during biocatalysis process development. Gas–liquid, liquid–liquid, and solid–liquid interfaces are present in almost every industrial application, from aerated oxidations to aqueous‐organic biphasic reactions and immobilized systems. Interfaces therefore can severely reduce catalyst lifetime. Oxidoreductases that are stable for tens of hours in solution may lose activity within minutes under air sparging, while whole‐cell systems exposed to organic solvents may show productivity shifts that correlate with the exposure to interfacial area. Yet interfaces are not always detrimental. Lipases, for instance, require interfacial activation to function, Pickering emulsions and colloidosomes can enhance both stability and turnover, and hybrid bio‐abiotic assemblies exploit interfaces to access new reactivity. The challenge is to recognize interfaces as measurable variables defined by interfacial area, renewal rate, and adsorption, rather than unpredictable side effects. In this perspective, we discuss the importance of recognizing interfaces during biocatalysis process design. We also highlight case studies where the outcomes depend on interfacial control and evaluate molecular, material, and reactor strategies to mitigate or exploit interface phenomena. By incorporating measurement of interfacial stability into standard workflows, we can transform interfaces from silent killers into controllable variables that affect productivity, cost, and sustainability in biocatalysis processes.