Proteases are enzymes that break the peptide bonds of proteins; they are divided into acid, neutral, and alkaline proteases. These enzymes can be obtained from plants, animals, and microorganisms in several conditions, such as high salt concentrations. The halophilic proteases possess stable activity at high temperature and ionic strength in presence of organic solvents. Some protease enzymes have potential uses in detergents, the pharmaceutical industry, bioremediation processes, and food industries. Serine proteases is a group of enzymes that catalyses hydrolysis of peptide bonds via a nucleophilic attack triggered by their active site serine. Serine proteases act sequence-specifically and are usually synthesized and secreted as inactive proenzymes (called zymogens) further activated by proteolysis. The best characterized members of this family play a role in intestinal digestion, blood coagulation and fibrinolysis (i.e. trypsin, thrombin or plasmin). In addition, several studies have pointed out the role of serine proteases in the central nervous system (CNS). Serine proteases contribute to cell migration, axon outgrowth and synapse elimination. In adult, they play a role in neuropeptide processing, regulation of neuronal survival and structural plasticity associated with learning and memory processes.