title: Production, rapid purification and catalytic characterization of extracellular phytase from Aspergillus ficuum.
abstract: A rapid purification scheme utilizing three chromatographic steps resulted in 6 fold purification of Aspergillus ficuum phytase (myo-inositol-hexakisphosphate 3-phosphohydrolase, EC 3.1.3.8). At pH 5.0 and 60 degrees C the enzyme performed acceptably for 2.0 hr with only 30% diminished catalytic rate at the end. Substrate concentration exceeding 2mM was inhibitory. The inorganic orthophosphate, the product and a weak inhibitor, exhibited a Ki of 1.9 x 10(-3)M. The extracellular phytase has the potential for industrial use since it can be over produced, easily purified, remain catalytically active for a longer period and is not subjected to severe product inhibition.
authors.affiliation: Southern Regional Research Laboratory, ARS, USDA, New Orleans, Louisiana 70124.
authors.forename: A H
authors.initials: AH
authors.lastname: Ullah
mesh_terms: D010832:6-Phytase / Q000032:analysis / Q000096:biosynthesis / Q000302:isolation & purification*; D001230:Aspergillus / Q000201:enzymology*; D002853:Chromatography, Liquid; D006868:Hydrolysis; D007700:Kinetics
chemical_list: D010832:6-Phytase