Studies on Protoplast Induction in the Yeast Phase of Histoplasma Capsulatum by Magnesium Sulfate and 2-Deoxy-D-Glucose

SUMMARY

Experiments to elucidate the possible mode of action of MgSO₄ with or without 2-deoxy-d-glucose (2DG) in inducing protoplasts in early log phase yeast cells of Histoplasma capsulatum Darling without added external enzymes are described and discussed. MgSO₄ is effective in a molarity range between 1.8 and 2.2 M. Below 1.8 M no protoplasts are formed, while 2.4 M MgSO₄ produces irreversible plasmolysis. For acceleration of protoplast formation, the optimum concentration of 2DG is 750 mg/100 ml medium. Protoplasts are formed at glucose concentrations ranging from 0.1% w/v to 1.25% w/v. Glucose concentrations of 0.1% w/v occasionally yield multiple budding whole yeast cells.