Microbial Peptidase in Food Processing: Current State of the Art and Future Trends

Enzymes are versatile and ecological biocatalysts that are biodegradable, which leads to lower environmental impacts. Peptidases are enzymes that catalyze the hydrolysis reaction of peptide bonds in proteins. Protein hydrolysis is fundamental in food processing, cleaning products, and pharmaceuticals, among others. Microbial peptidases have been the preferred source for developing new enzymes, besides their advantages compared to plant or animal sources. This is owing to their characteristics, e.g., fast growth, wide diversity of microbial enzymes, longer shelf life, and potential for genetic manipulation of microorganisms. Enzymes catalyze biochemical reactions and are highly specific. They generally work in mild conditions and depend on their native conditions, such as pH, temperature, and solvent characteristics. However, the protease used must tolerate operational adversities such as extreme pH and temperature in industrial processes. For this, it is necessary to discover new peptidases and improve existing ones. Methods of metagenomic selection and genome mining or through extremophile diversity (e.g., thermophilic, cold-active, alkali tolerant, acidophilic, and halophilic microorganisms) have been used in the discovery of new enzymes. Protein engineering (by directed evolution, rational design, semi-rational design, and de novo design) and enzyme immobilization are strategies used to improve the catalytic properties, efficiency, and stability of enzymes. This review aimed to critically discuss the current state of the art and future trends of microbial peptidases, highlighting their applications in food processing. Graphical Abstract