The below mentioned article provides a quick note on the Sporulation of Bacteria.
Bacteria produce several types of spores called gonidia, sporangiospores, arthrospores (oidia), conidia, cysts and endospores.
Endospores (Fig. 2.12):
They are highly thick-walled and resistant spores which are formed in response to adverse environment, presence of harmful waste products or ageing of bacterial colony.
A part of protoplast of the bacterial cell containing the nuclear body or nucleoid stores food undergoes dehydration and separates from the rest by means of mesosome and in growth of plasma membrane.
It is called endospore prunordium. The primordium secretes a wall around it. More wall materials are deposited over it by the surrounding cytoplasm to form the endospore. The residual cytoplasm and wall of parent bacterium undergo autolysis.
The liberated endospore is dispersed by air currents and on germination forms a new bacterium. Endospores can easily tolerate a temperature of ± 100°C. Toxic chemicals have no effect on them.
The resistant nature of endospores is due to their thick wall, low water content and the presence of an anticoagulant chemical known as dipicolinic acid. Fortunately, only two pathogenic bacteria Clostridium tetani and Bacillus anthracis produce endospores.