endospórákat

Endospórákat are dormant, tough, and non-reproductive structures produced by some bacteria. They are formed within the bacterial cell, hence the name "endo" meaning within. The primary purpose of endospore formation is to ensure the survival of the bacterium during unfavorable environmental conditions, such as extreme temperatures, radiation, starvation, or chemical exposure. The process of forming an endospore is called sporulation.

During sporulation, the bacterium replicates its DNA and encapsulates one copy within a protective spore coat. This coat is made of several layers, including a cortex and a spore coat, which provide resistance to heat, chemicals, and radiation. The cytoplasm of the endospore contains a lower water content and higher concentration of dipicolinic acid, which contributes to its heat resistance. Once formed, the endospore can remain viable for extended periods, even centuries, until favorable conditions return.

When conditions become suitable for growth, the endospore germinates. This process involves the activation of enzymes that break down the protective layers and the rehydration of the spore's core, allowing the bacterium to resume its vegetative, actively growing state. Not all bacteria are capable of forming endospores; this ability is primarily found in species belonging to the phyla Firmicutes, such as Bacillus and Clostridium. The resistance of endospores makes them a significant concern in sterilization processes, as they are difficult to kill.