Formation of protoplasts from Ustilago maydis.

Protoplasts of Ustilago maydis were obtained by incubating sporidia of the fungus with a combination of Helicase and a commercial "Onozuka" R-10 enzyme preparation of Trichoderma harzianum in the presence of 0.6 M (NH4)2 SO4 as an osmotic stabilizer. In the presence of the organic stabilizers sorbitol and sucrose, however, the release of protoplasts was inhibited. Combinations of Helicase with other lytic enzymes such as cellulase from Aspergillus niger, cellulase and hemicellulase from Rhizopus, and Driselase or Nagarse were inactive.