Biochemical features and biotechnological potential of a proteolytic extract from a psychrophilic Antarctic bacterium.

Proteases are hydrolases that act on peptide bonds, releasing amino acids and/or oligopeptides, and are involved in essential functions in all organisms. They represent an important segment of the global enzyme market, with applications in the food, leather, detergent, and pharmaceutical industries. Depending on their industrial use, proteases should exhibit high activity under extreme conditions, such as low temperatures, e.g. cold-active protease may have potential uses in the detergent industry. Cold-active enzymes show high catalytic constants (k(cat)) at low temperatures and thermolability, allowing their inactivation at moderate temperatures. This work aimed to characterize an extracellular proteolytic extract produced by an Antarctic isolate identified as Flavobacterium sp. strain AU13, and to evaluate its biotechnological potential as a detergent additive. By mass spectrometry analysis, we identified a major 50 kDa protease, with high identity with an epralysin from Pseudomonas fluorescens Pf0-1, an alkaline extracellular metalloprotease belonging to the serralysin subfamily. The AU13 proteolytic extract showed metalloprotease activity and, maximal activity over a wide pH range (pH 5 to 8); it also showed maximal activity at 40 °C, suggesting that this extracellular protease is a cold-active enzyme. The AU13 proteolytic extract demonstrated stable and compatible activity with surfactants and oxidants, making it a promising additive for commercial laundry detergents. Its ability to function effectively in cold-water washing conditions offers a significant advantage over conventional enzymes, potentially improving energy efficiency in industrial processes. The biochemical properties and performance of the AU13 proteolytic extract in the presence of laundry detergents, suggest that AU13 produces an extracellular protease with a biotechnological potential.