Abstract: Crude phytase solution separated from Agrobacterium radiobacter fermentation broth was used to hydrolyze wheat bran for phytic acid dephosphorization. Using one-factor-at-a-time combined with orthogonal array design method, such process conditions as enzyme amount, substrate concentration, pH, temperature and hydrolysis time were optimized to be 750 U/g, 40 mg/mL, 7, 45 ℃, and 5 h, respectively. Under the optimized conditions, the hydrolysis rate of phytic acid was up to 81.50%.

Key words: phytase, dephosphorization, wheat bran