Changes in the Cell Morphology and the Release of Soluble Constituents from the Washed Cells of Bacillus subtilis by the Action of Protamine

Abstract

Clupeine sulfate, a fish protamine is shown to significantly alter the morphology of washed cells of Bacillus subtilis, Shaking incubation with protamine resulted in the lysis of the cells. Electron microscopy with the thin sections of protamine treated cells revealed that protamine causes great damage to the cell-wall particularly to the outer layer of the wall. Protamine is adsorbed in fairly large amounts by isolated cell-wall, The observed pattern of uptake, measured under different pH indicates that uptake involves firm but reversible adsorption to the ionized sites on the cell, Protamine produces rapid and marked damage to cell membranes of B. subtilis causing leakage of 260nm absorbing material, inorganic phosphate and pentose from the washed cells. An optimum concentration of protamine is necessary to cause maximum leakage of cellular material. Investigations indicate that membrane damage caused by bactericidal concentration of protamine is irreversible. It is concluded that the action of polycationic protamine resembles with the action of some surface active cationic agents and polypeptide antibiotics.