Abstract
Conditions for isolation and culture of protoplasts from Paecilomyces fumosoroseus were studied. A high yield of protoplasts from young mycelia of P. fumosoroseus was obtained by treatment with Driselase. Potassium chloride and sodium chloride were more effective than mannitol, sorbitol, glucose, and magnesium sulfate as osmotic stabilizers for the preparation of protoplasts. More than 20% of the protoplasts were without a nucleus, 50-70% contained a single nucleus, and other protoplasts contained two or more nuclei. Glucose and sodium chloride were effective stabilizers for reversion of protoplasts, while no stabilizing effect was observed from mannitol and sorbitol. The colonies on agar medium containing glucose as osmotic stabilizer grew rapidly, but not sodium chloride was used.