Proteolytic bacteria are microorganisms that break down protein, especially in milk and dairy products, causing unwanted odor and taste. Like lipolytic bacteria, such bacteria are not desired to be present in milk and dairy products. Some of these bacteria cause significant quality losses in case of long storage of dairy products.

Such bacteria are generally found in soil and water and cause degradation of foodstuffs with rich protein. Some of the proteolytic bacteria are particularly effective in canned foods. It produces enzymes that break down fat, carbohydrates and protein, some of which are found in food products. Some of them show growth characteristics even in the refrigerator.

Proteolytic bacteria counts are determined by standard smear culture counting method in laboratories. In these studies, special media for the proteolytic properties of microorganisms are used. The most used medium for this purpose is Calcium Caseinate Agar.

Briefly, proteolytic microorganisms hydrolyze proteins and cause undesirable tastes and odors in food products. Due to its strong proteolytic properties, it causes undesirable changes in dairy products, meat products, seafood and cheese varieties. Especially during the storage period these microorganisms multiply and make the food unconscious.

Proteolytic bacterial counting is an important microbial criterion for the assessment of quality losses in food products. The protease enzyme in psychrotrophic bacteria, which causes deterioration in milk and dairy products, maintains its activity even after microorganisms lose their viability after long-term milk production. Some mold and yeast species may also exhibit proteolytic activity.

In advanced laboratories, studies are carried out for the determination of proteolytic bacteria count in foodstuffs within the scope of microbiological analyzes. These studies are based on standards and test methods published by national and international organizations.