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Mohammad ali Zarei

Mohammad ali Zarei

Academic rank: Associate Professor
ORCID: 1344-8207-0001-0000
Education: PhD.
ScopusId: 56739346200
Faculty: Faculty of Science
Address: Department of Biological sciences, Faculty of Science, University of Kurdistan, Sanandaj, IRAN.
Phone: 00988733664600-2482

Research

Title
Extraction and kinetic characterization of wheat grain phytase
Type
Presentation
Keywords
Phosphatase, Phytate, Kinetics, Phosphate
Year
2011
Researchers Mohammad ali Zarei

Abstract

Introduction: Phytases are a special class of phosphatases produced by plants and microorganisms that catalyze sequential hydrolysis of phytate to less phosphorylated myo-inositol derivatives and inorganic phosphate. Phosphorus, like nitrogen, is essential for all forms of life. Facing the problem of phosphorus deficiency in animal feed and the problem of phosphorus pollution in areas of intensive livestock production, phytase seems destined to become increasingly important. Materials andMethods: Phytase activitywasmeasured, at 55 °C in a buffer containing 200 mMsodium acetate, pH 5.5, and 1 mMCaCl2. The activity of phytasewas calculated as release of inorganic phosphate (Pi) perminute. Activity response to pHwas examined at 55 °C using a 0.1 M glycine buffer in the pH ranges of 2–4 and 9–10, 0.1 M sodium acetate buffer in the pH range of 4–6.5, and a 0.1 MTris buffer in the pH range of 6–9. The optimum temperature was determined in 200 mM sodium acetate,1 mMCaCl2 at pH 5.5 and 1.5 mMphytic acid as substrate in the range from 25 to 75 °C with 10 °C increments. Kinetic properties were estimated with sodium phytate as substrate. Initial velocity was determined at substrate concentrations ranging from 1.0 to 25.0 mM sodium phytate and four linear plots of the data were constructed. Protein concentration was determined by Lowry's Method. Results: The extracted enzyme from wheat (Triticum aestivum) showed optimum activity at 55 °C. This is similar to the temperature optimum reported for several other phytases. The extracted enzyme exhibits maximum activity at pH 5.5 with two other peaks at pH 3 and pH 9, maximum activity observed in the pH range 3–5, is characteristic of the stomach after initial ingestion of feed, but maximum activity observed inpH9may be good for intestinal environment.When phytate was used as substrate, KmandVmaxwere calculated to be 1.41 mMand 5.51 μM/min respectively. Conclusion: This Km is higher than the value which previously has been reported fo