Protoplast-bursting factor (P. B. factor) has a little antibacterial activity and is capable of inhibiting the growth of Bacillus megaterium.
The cell suspensions required P. B. factor and Mg⁺⁺ for the oxidation of glucose-6-phosphate but did not require them for that of glucose.
Leakage of various cellular components into the surrounding menstruum occured when the cell suspension was subjected to treatment with P. B. factor. These materials were identified as protein, deoxyribonucleic acid, ribonucleic acid, and amino acids.
Under an electron microscope, the cytoplasm of the cells treated with P. B. factor was apparently less dense than the control, which seemed to suggest that the cytoplasm had leaked out of the inside of the cell through the membrane by the treatment of P. B. factor.

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