Abstract: The effects of initial medium pH, culture time and temperature, and corn flour concentration in the medium on the production of saccharification enzyme, liquefaction enzyme and protease by Rhizopus ERh3421 were explored in the present study. To enhance the production of saccharification and liquefaction enzymes, initial medium pH, culture temperature and corn flour concentration in the medium were optimized using an L9 (33) orthogonal array design. The results obtained were analyzed by one-way analysis of variance. The optimal culture conditions for enhanced enzymes production were initial medium pH 5.2, 30 ℃ and 5 g/100 mL of corn flour concentration in the medium. Under these conditions, the activities of saccharification and liquefaction enzymes in fermentation broth were 9.43 × 103 U/g and 6.83 × 103 U/g, respectively.

Key words: Rhizopus ERh3421, conditions for enzymes production, enzyme activity, optimization