Interaction of the Bacillus subtilis spore protoplast, cortex, ion-exchange and coatless forms with glutaraldehyde

Bacillus subtilis spores with altered ionic content were tested for their susceptibility to lysis with lysozyme or sodium nitrite following treatment with glutaraldehyde. The Ca-form was more sensitive to glutaraldehyde (pH 4.0 and pH 7.9) than the untreated or H-form. Removal of spore coat dramatically increased sensitivity of the spore to glutaraldehyde. Pretreatment of spores, the coats of which had been extensively removed, with glutaraldehyde (pH 7.9) reduced the rate of lysis by lysozyme and by sodium nitrite, whereas glutaraldehyde at pH 4.0 had little effect. Glutaraldehyde pretreatment (pH 4.0 and pH 7.9) reduced the amount of hexosamine released by lysozyme but not by nitrite from isolated cortical fragments. Spore protoplasts were more susceptible to 0.01% (w/v) glutaraldehyde at pH 4.0 and isolated spore coats adsorbed alkaline glutaraldehyde more rapidly. These results are discussed in terms of a possible mode of action of glutaraldehyde on the bacterial spore.