Production, purfication and characterization of phytase from Aspergillus tubingensis HBF 202

Extracellular phytase produced by Aspergillus tubingensis HBF 202 in PSM was purified 101 - fold with a recovery of % 7,24 referred to the phytase activity in the crude extract using, amonium sulphate precipitation, Phenly Sepharose CL-4B, DEAE Sepharose CL-6B and Sephadex G-100. SDS-PAGE of the purrified enzyme gave a single stained band at a molecular mass of approximately 63.48 kDa. The temperature and pH for maximum activity of the enzyme were 60°C and 2.50, respectively. Km and Vmax values for sodium phytate of the enzyme were calculated to be 267 μM and 109.89 U/mL, respectively. The phytase exhibited broad substrate specificity. The phytase activity was stimulated by Ba2+and Li+ cations inhibited by Fe2+, Al3+ ve Pb2+cations. The enzyme activity was inhibited in the presence of NBS, PMSF, DTNB and 2,3-bütandion while CMC, DTT, ve β- merkaptoetanol were actvited. This results shows that tryptophan, cysteine, arginine and serine residues play an important role in the catalytic process. Sorbitol enchances thermostability of phytase. The enzyme was detemined to be highly againist organic solvents.