Phytases belong to the class of phosphatases that catalyze the hydrolysis of phosphoric acid. Phytase performs stepwise cleavage of orthophosphate ions of phytic acid to form intermediates of penta-, tetra-, tri-, di-, and inositol monophosphates (Nayani NR, Markakis P., 1986).
In accordance with the International Nomenclature of enzymes IUPAC-IUBMB there three types of phytases: 3-phytase, 5-phytase and 4/6-phytase. The different types begin the hydrolysis of phytic acid at different carbon atoms of the inositol ring, resulting in the formation of different isomers. However, the mechanism of hydrolysis and the structure of the proteins from the same type phytases may be variable. Also, Phytases of the same type can be further classified as acidic, neutral or alkaline phosphatases, according to their optimal pH levels.
Phytases - a group of enzymes belonging to the subclass of phosphatases carrying release of at least one phosphate ion from the molecule of phytic acid. Hydrolysis of phytic acid forms the lower, i.e. containing less than six residues of phosphoric acid, inositol and inorganic phosphate, as well as associated with phytates released cations.
First, phytase activity was discovered in rice bran (Suzuki U. et. Al., 1907) and calf blood (McCollum EV, Hart EB, 1908), i.e., in largely different living organisms. Later, phytases were localized in bacteria and fungi, including yeast. No phytase and phytate hydrolysis is carried out in the digestive secretions of monogastric animals, including humans, under the influence of enzymes and the acidic microflora environment of the stomach.
Most (about two thirds) of the total phosphorus in plant feed is present in the form of salts of phytic acid. Phytase is responsible for both synthesis and hydrolysis of phytic acid. Due to the inability of livestock and poultry to endogenously produce phytase, phosphorus, calcium, protein and other related phytic acid nutrients become less available. For the management of potential nutrient feed and more cost-effective and environmentally friendly production of meat, microbial phytase should be used. Enrichment of the diet with microbial phytase makes more phosphorus, calcium, zinc and copper available, improves digestibility and stimulates weight gain. Effective use of microbial phytase should consider the ratio in the diet of calcium and phosphorus (Ca: P), vitamin D3, composition of the diet, age, and genetic features of animals.