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An endospore stain of the cell Bacillus subtilis showing endospores as green and the vegetative cell as red Phase-bright endospores of Paenibacillus alvei imaged with phase-contrast microscopy An endospore is a dormant , tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota .
Endospores can last for decades in multiple hard conditions, such as drying and freezing. This is because the DNA inside the endospore can survive over a long period. Most bacteria are unable to form endospores due to their high resistance, but some common species are the genera Bacillus ( over 100 species) and Clostridium (over 160 species).
Perhaps the best known bacterial adaptation to stress is the formation of endospores. Endospores are bacterial survival structures that are highly resistant to many different types of chemical and environmental stresses and therefore enable the survival of bacteria in environments that would be lethal for these cells in their normal vegetative ...
Endospore-forming bacteria can cause disease; for example, anthrax can be contracted by the inhalation of Bacillus anthracis endospores, and contamination of deep puncture wounds with Clostridium tetani endospores causes tetanus, which, like botulism, is caused by a toxin released by the bacteria that grow from the spores. [101]
Bacillus subtilis (/ b ə ˈ s ɪ l. ə s s u b ˈ t iː. l i s /), [3] [4] known also as the hay bacillus or grass bacillus, is a gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges.
B. anthracis endospores, in particular, are highly resilient, surviving extremes of temperature, low-nutrient environments, and harsh chemical treatment over decades or centuries. [citation needed] The endospore is a dehydrated cell with thick walls and additional layers that form inside the cell membrane.
The Wirtz-Conklin stain is a special technique designed for staining true endospores with the use of malachite green dye as the primary stain and safranin as the counterstain. Once stained, they do not decolourize. The addition of heat during the staining process is a huge contributing factor. [15]
Listeria species are Gram-positive, rod-shaped, and facultatively anaerobic, and do not produce endospores. [4] The major human pathogen in the genus is L. monocytogenes. Although L. monocytogenes has low infectivity, it is hardy and can grow in a refrigerator temperature of 4 °C (39.2 °F) up to the human body temperature of 37 °C (98.6 °F ...