Abstract

Phytases belong to the class of phosphatases, which catalyze the hydrolysis of phytic acid to inorganic phosphate and myo-inositol phosphate derivatives. The enzyme has potential applications in food and feed industries for ameliorating digestibility and assimilation of nutrients of foods and feeds by mitigating the anti-nutritional effects of phytic acid. Phytases have been shown to be useful in improving growth of poultry, pigs and fishes, and they play a role in promoting growth of plants, as well as improve the nutritional quality of bread, soymilk and oil seed cakes by dephytinization. The crystal structures of some phytases have been analyzed for understanding the reaction mechanism. The phytases with desirable properties have been generated through protein engineering approaches, since native phytases do not possess all the properties of an ideal additive feed/food. Recent developments on the characteristics of an ideal phytase, crystal structure, protein engineering, and the potential biotechnological applications of microbial phytases with special reference to their utility in improving growth performance of monogastrics, dephytinization of foods and feeds, plant growth promotion, and combating environmental phosphorus pollution will be discussed in this review.

Key words: Phytic acid, microbial phytase, crystal structure, monogastrics, protein engineering, dephytinization, plant growth promotion.