Hosseyni pajooh - Biotechology Department, Iranian Research Organization for Science & Technology،Tehran
Kh Sharifi - Biotechology Department, Iranian Research Organization for Science & Technology،Tehran
N Mirdamadi - Biotechology Department, Iranian Research Organization for Science & Technology،Tehran
F Aziz mohseni - Biotechology Department, Iranian Research Organization for Science & Technology،Tehran

Phytase (myo-inositol hexakisphosphate phosphohydrolase) catalyzes and hydrolyzes the phytic acid (myo-inositol hexakiphosphate)، which is the main form of stored phosphorus in seeds. Organically bound phosphate of phytic acid is not utilized by monogastric animals specially poultry، thereby decreases the bioavailability of phosphorus. Furthermore، since phytic acid chelates minerals such as Cu++، Zn++ and Fe++، It also reduces absorption of these ions. Addition of phytase in diet of poultry helps hydrolysis of phytic acid in gastric system، resulting increases of available phosphorus and reducing anti nutrition effects of phytic acid. Stability and preservation conditions of phytase produced by Aspergillus ficuum PTCC 5288 and also its formulation with bran for adding to poultry diet were studied. Stability of the enzyme was almost the same and without noticeable decrease in its activity in lyophilized form (4°C and-18°C) ،dried (4°C and-18°C)،and liquid(4°C and-18°C) for 56 days ،except dried form at room temperature. In all above mentioned form، crude enzyme was more stable. Also the best pH for preservation was 7. To formulate the enzyme for adding to poultry diet، use of complete culture، air dried at 30°C and formulated with bran has the best result in stability and consumption، so was stable for more than 6 month in 4°C without noticeable decrease in its activity.

فیتاز، اسید فیتیک (فیتات)، تغذیه طیور آسپرژیلوس فیکوم، سبوس