Search results
Results From The WOW.Com Content Network
Endospores are commonly found in soil and water, where they may survive for long periods of time. A variety of different microorganisms form "spores" or "cysts", but the endospores of low G+C gram-positive bacteria are by far the most resistant to harsh conditions. [3]
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). [2]
Endospores exhibit more extreme isolation from their environment in terms of cell wall thickness, impermeability to substrates, and presence of dipicolinic acid, a compound known to confer resistance to extreme heat. [7] Microbial cysts have been likened to modified vegetative cells with the addition of a specialized capsule. [7]
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]
Some genera of Gram-positive bacteria, such as Bacillus, Clostridium, Sporohalobacter, Anaerobacter, and Heliobacterium, can form highly resistant, dormant structures called endospores. [93] Endospores develop within the cytoplasm of the cell; generally, a single endospore develops in each cell. [94]
The normal, reproducing cells of Clostridium, called the vegetative form, are rod-shaped, which gives them their name, from the Greek κλωστήρ or spindle. Clostridium endospores have a distinct bowling pin or bottle shape, distinguishing them from other bacterial endospores, which are usually ovoid in shape.
During spore formation the bacteria produce crystals of such proteins (hence the name Cry toxins) that are also known as parasporal bodies, next to the endospores; as a result some members are known as a parasporin. The Cyt (cytolytic) toxin group is another group of delta-endotoxins formed in the cytoplasm.
Clostridium tetani is durable due to its endospores. Pictured is the bacterium alone, with a spore being produced, and the spore alone. Tetanus is caused by the tetanus bacterium, Clostridium tetani. [1] The disease is an international health problem, as C. tetani endospores are ubiquitous.