Ultrastructural effects of chemical agents and moist heat on Bacillus subtilis. I--Effects on vegetative cells.

The ultrastructural alterations induced by treatment of vegetative Bacillus subtilis cells with organic solvents, trichloroacetic acid (TCA) and moist heat were examined by electron microscopy. Organic solvents disorganize the membrane and change the asymmetric unit membrane profile to a symmetric profile. They also lead to partial solubilization of the membrane and produce small or extensive gaps. Membrane damaging activity increases in the following order: xylene = toluene less than octanol less than choroform. TCA coagulates the cytoplasm which shows large, electron-dense, pronase-sensitive blocks. Moist heat alters both the membrane and the cytoplasm.