10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 2 2012 (April - June) An extracellular phytase from lessThan i greaterThan Aspergillus tamari lessThan /i greaterThan was purified about 51-fold to apparent homogeneity with a recovery of 20.3% referred to the phytase activity in the crude extract. Purification was achieved by ammonium sulphate precipitation, ion chromatography and gel filtration. The purified enzyme behaved as a monomeric protein with a molecular mass of about 85 kDa and exhibited maximal phytate-degrading activity at pH 8.5. Optimum temperature for the degradation of phytate was 28°C. The kinetic parameters for the hydrolysis of nitro phenyl phosphate disodium salt were determined to be Km = 54 μmol lessThan sup greaterThan -l lessThan /sup greaterThan and kcat = 190 sec lessThan sup greaterThan -1 lessThan /sup greaterThan at pH 8.5 and 28°C. The purified enzyme was rather specific for phytate dephosphorylation. It was shown that the phytase preferably dephosphorylates lessThan i greaterThan myo lessThan /i greaterThan -inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via D-Ins(1,2,4,5,6)P5, D-Ins(1,2,5,6)P4, D-Ins(1,2,6)P3, D-Ins(1,2)P2 to finally Ins(2)P Shah, K.B. And Ratna Trivedi Aspergillus tamari, phytate-degrading enzyme, phytate, phytase. 775-783