Protoplasts of0.5 to 5.0 x 107 ml-1 were released from mycelia of approximately 300 mg (fresh weight) when young mycelial mass was suspended in adjusted enzyme solution and was incubated at 30 C for 1 hr. The average diameter of the protoplast was 4.0 !-till- The protoplasts were readily obtained by using 0.6 M NaCl as an osmotic stabilizer (Fig. 1).