Microbial Proteases as Product-Directed Catalysts for Industrial Proteolysis.

Microbial proteases are widely used for industrial proteolysis in detergents, food processing, hydrolysate production, product stabilization, and side-stream valorization. Their industrial value is not determined by general activity or degree of hydrolysis alone, but by the ability of a defined catalyst to operate reliably under process conditions and generate the intended product endpoint. This review frames microbial proteases as product-directed biocatalysts whose performance depends on the alignment of catalyst identity, process compatibility, substrate access, and product outcome. Production, maturation, and immobilization are considered determinants of the deployed enzyme form, while biocatalyst identity, process translation, product outcome, and endpoint refinement provide a framework for evaluation. Across protease classes, industrial utility is shaped by acid-window matching, operating-window engineering, catalyst definition, metal-state compatibility, and peptide-pool refinement. Data-guided workflows integrating protease discovery and engineering, cleavage prediction, peptidomic mapping, real-substrate validation, and enzyme-system optimization offer a path toward more predictable product-oriented industrial proteolysis.