1. Dehydrated Cytoplasm: Spores are incredibly dehydrated. They contain very little water compared to their vegetative counterparts. This lack of water significantly hinders the effectiveness of heat-based sterilization methods. Water is essential for many chemical reactions, including those involved in protein denaturation, a crucial step in killing cells. Without sufficient water, the enzymes and proteins within the spore remain relatively stable even at high temperatures.
2. Tough, Protective Coat: Spores are encased in a thick, multi-layered coat composed of proteins, lipids, and peptidoglycans. This coat acts as a physical barrier, protecting the spore's core from heat, chemicals, and radiation. This coat also contributes to the spore's resistance to drying and nutrient deprivation, further contributing to its resilience.
