Fine Structure of Protoplasts of Aspergillus nidulans

SUMMARY: Observations on the ultrastructure of Aspergillus nidulans protoplasts obtained by treatment of mycelium with Streptomyces RA lytic enzyme show that they were free of wall material. The preparations contained two types of protoplasts, released at different times during the lytic enzyme-mycelium incubation. Those released first contained small vesicles and a high density of ribosomes. The type released later had large vacuoles and fewer ribosomes. It is suggested that these differences reflect the hyphal location and origin of the protoplasts.