Digestive Enzymes of the Crustaceans Munida and Their Application in Cheese Manufacturing: A Review

Crustaceans Munida (fam. Galatheideae, ord. Decapodi) were fished in the Southern Adriatic Sea and their proteolytic activities were characterized and tested for potential application in cheese manufacturing. Enzymes extracted from whole crustaceans, mainly serine proteases, showed high caseinolytic and moderate clotting activities. Analysis by 2D zymography of the digestive enzymes extracted from Munida hepatopancreas, showed the presence of several isotrypsin- and isochymotrypsin-like enzymes in the range of 20–34 kDa and 4.1–5.8 pI. Moreover, specific enzymatic assays showed the presence of aminopeptidases and carboxypeptidases A and B. Overall, optimum activity was achieved at pH 7.5 and 40–45 °C. Caseinolytic activity, determined both spectrophotometrically and by SDS gel electrophoresis, indicated higher activity on β-casein than on α-casein. Miniature cheddar-type cheeses and Pecorino-type cheeses were manufactured by adding starter, rennet and Munida extracts to milk. Reverse-phase HPLC and MALDI-ToF mass spectrometry showed a more complex pattern of proteolytic products in cheeses made using Munida instead of chymosin. Munida extracts were found to degrade the chymosin-derived β-casein fragment f193–209, one of the peptides associated with bitterness in cheese. In conclusion, Munida digestive enzymes represent a promising tool for development of new cheese products and shorten cheese ripening when used either alone or in addition to calf rennet

The role of lysosomal cysteine proteases in crustacean immune response

Over the long course of evolution and under the selective pressure exerted by pathogens and parasites, animals have selectively fixed a number of defense mechanisms against the constant attack of intruders. The immune response represents a key component to optimize the biological fitness of individuals. Two decades ago, prevention and control of diseases in crustacean aquaculture systems were considered priorities in most shrimp-producing countries, but knowledge was scarce and various pathogens have severely affected aquaculture development around the world. Scientific contributions have improved our understanding of the crustacean immune response. Several studies confirm the central role played by proteases in the immune response of animals, and the cooperative interaction of these enzymes in a wide variety of organisms is well known. This review summarizes the current information regarding the role of cysteine proteases in the immune system of Crustacea and points to aspects that are needed to provide a better integration of our knowledge