Histidine Acid Phytases of Microbial Origin

— This review is focused on analysis of the biological diversity of phytase-producing microorganisms capable of degrading phytate to inorganic phosphate. General approaches to microbial phytase classification are discussed, with a particular emphasis on histidine acid phytases (HAPs), which catalyze specific cleaving of myo -inositol hexakisphosphate. The effect of glycosylation and various effectors on enzyme thermostability and activity of phytases are described. The data on the biosynthesis of histidine acid phytases, their substrate specificity, and on the mechanism of myo -inositol hexakisphosphate hydrolysis are considered. A conclusion is made concerning the biotechnological potential of this group of microbial enzymes.