Considerations on the value of freeze-etching technique in studying the ultrastructure of some anaerobic bacteria

Samples from periodic cultures of Clostridium perfringens, Clostridium oedematiens, Clostridium tetani and Bifidobacterium bifidum grown in liquid nutrient media were studied after freeze-fracturing and etching without pretreatment by means of chemical agents including cryo-protectants. Subunits in the cell all of Cl. tetani and differences in the distribution of globular particles in the plasma membrane of the investigated bacteria are revealed.