Microbial cyst

A microbial cyst is a resting or dormant stage of a microorganism, that can be thought of as a state of suspended animation in which the metabolic processes of the cell are slowed and the cell ceases all activities like feeding and locomotion. Many groups of single-celled, microscopic organisms, or microbes,^[1] possess the ability to enter this dormant state.

Encystment, the process of cyst formation, can function as a method for dispersal and as a way for an organism to survive in unfavorable environmental conditions. These two functions can be combined when a microbe needs to be able to survive harsh conditions between habitable environments (such as between hosts) in order to disperse. Cysts can also be sites for nuclear reorganization and cell division, and in parasitic species they are often the infectious stage between hosts. When the encysted microbe reaches an environment favorable to its growth and survival, the cyst wall breaks down by a process known as excystation.^[2]

Environmental conditions that may trigger encystment include, but are not limited to: lack of nutrients or oxygen, extreme temperatures, desiccation, adverse pH, and presence of toxic chemicals which are not conducive for the growth of the microbe.^[3][4]