[Objective] To explore the efficient way for the preparation of Aspergillus oryzae protoplast.[Method] The statistics of protoplast yield by the enzymolysis of mycelia with different culture time,different osmotic stabilizers and different concentrations of enzyme system was carried out in this study.[Result] The protoplast yield was higher when the mycelium was cultivated for 108 h,and the osmotic stabilizer was 0.8 mol/L of NaCl.With the enzymes system of 2 mg/ml of lysozyme,6 mg/ml of cellulose and 6 mg/ml of glusulase,the protoplast yield achieved its highest,which was up to 9.0×105 per ml.[Conclusion] The yield of protoplast was affected by the situation of mycelia themselves and external conditions.This study had provided a basis for the preparation of a large number of active protoplasts and the further researches on cell fusion.
