What are endospores?
Endospores are dormancy capsules formed by certain species of bacteria of the phylum Firmicutes. The formation of endospores is analogous to going into hibernation to survive nonideal conditions, such as lack of nutrients or cold. Within a dormant state, encased in an endospore, a bacterium may remain alive significantly longer than it could otherwise.
Endospores can form within different areas of the vegetative cell. They can be central, subterminal, or terminal. Central endospores are located within the middle of the vegetative cell. Terminal endospores are located at the end of the vegetative cell. Subterminal endospores are located between the middle and the end of the cell.
When food such as carbon or nitrogen become limited, highly resistant endospores form inside mother cell. These endospores usually occurs in Gram-positive bacteria and enable bacteria to lie dormant for extended periods, even centuries. Endospores trapped in amber for 25 million years have germinated when placed in nutrient media. Endospores of the bacterium Bacillus anthracis were used in the 2001 anthrax attacks.
Fungi and Bacillus are capable of producing endospores. The endospores provide a great "niche" for microbes to chill until conditions are optimal. However, sometimes heat activates these endospores. Meaning, the Bacillus is able to divide and replicate after heat because the heat activated the endospore.
Why would endospores not be present in a 12 hour batch culture but would be present in 14 day batch culture?
Endospores only form under unfavorable conditions that threaten the survival of the bacteria (and only some bacteria are capable of producing endospores). Also, the process of endospore formation requires 8-10 hours. Assumably, the 12 hour culture would still have an abundant supply of nutrients and therefore would not require the production of endospores to survive; the 14 day culture would have a much higher number of organisms which had been using up the supply of…
Endospores are thick-coated, resistant cells produced within a bacterial cell that has been exposed to harsh conditions. Endospores are inert and can endure extreme conditions like radiation, heat and cold, absence of nutrients and water. When conditions are good, they produce vegetative cells and thrive. When condition turn unfavorable, endospores are produced again and they remain inert. Vegetative cells are any cells of plants or animals that do not participate in reproduction. These are vulnerable…