Phytate is the major storage form of phosphorus in cereals and legumes. However, monogastric animals such as pig, poultry and fish are not able to metabolise or absorb phytate (or phytic acid) and therefore it is excreted, leading to phosphorous pollution in areas of intense livestock production. Moreover, phytic acid also acts as an antinutritional agent in monogastric animals by chelating metal agents such as calcium, copper and zinc.
In order to provide sufficient phosphates for growth and health of these animals, inorganic phosphate is added to their diets. Such addition can be costly and further increases pollution problems.
Through the action of phytase, phytate is generally hydrolysed to give lower inositol-phosphates and inorganic phosphate. Phytases are useful as additives to animal feeds where they improve the availability of organic phosphorus to the animal and decrease phosphate pollution of the environment (Wodzinski R J, Ullah A H. Adv Appl Microbiol. 42, 263-302 (1996)).
A number of phytases of fungal (Wyss M. et al., Appl. Environ. Microbiol. 65 (2), 367-373 (1999); Berka R. M. et al., Appl. Environ. Microbiol. 64 (11), 4423-4427 (1998); Lassen S. et al., Appl. Environ. Microbiol. 67 (10), 4701-4707 (2001)) and bacterial (Greiner R. et al Arch. Biochem. Biophys. 303 (1), 107-113 (1993); Kerovuo et al., Appl. Environ. Microbiol. 64 (6), 2079-2085 (1998); Kim H. W. et al., Biotechnol. Lett. 25, 1231-1234 (2003); Greiner R. et al., Arch. Biochem. Biophys. 341 (2), 201-206 (1997); Yoon S. J. et al., Enzyme and microbial technol. 18, 449-454 (1996); Zinin N. V. et al., FEMS Microbiol. Lett. 236, 283-290 (2004))) origin have been described in the literature.