of peptone resulted in great enhancement of enzyme production (125 ±4.9 U/g ds). This result represented 1.75-fold compared to the control (without the addition of peptone). The study of different organic and inorganic nitrogen sources appeared that peptone was the most favorable nitrogen source for enzyme production. On the contrary, Vohra and Satyanarayana (2002); Hassouni et al. (2002) reported that (NH4)2HPO4 was the most favorable nitrogen source for
Mycelophothora thermophila phytase production. On the other side, (Lan. et al. 2002) reported that soybean milk significantly
increased the phytase production by Mitsuokella jalaludinni.