In bacteria (for instance, Azotobacter sp.), encystment occurs by changes in the cell wall; the cytoplasm contracts and the cell wall thickens. Bacterial cysts differ from endospores

in the way they are formed and also the degree of resistance to unfavorable conditions. Endospores are much more resistant than cysts.

What causes Encystment?

The factors inducing cyst formation are unknown, but stressful environmental conditions (e.g., reserve or oxygen depletion, pH alteration, temperature variation, and pollution) have been suggested. Cysts have a distinctive contracted, oval form, with thick cuticular layers.

Why does Encystment occur protozoa?

Many protozoa also produce cysts under other adverse environmental conditions, such as food deprivation. ... Still other protozoa incorporate encystment into the life cycle following feeding (the “digestive cyst”) or during cell division (the “reproductive cyst”).