Inclusion bodies are non-living substances present in the vacuoles, cytoplasm or cell wall. They are a kind of storage granules lying freely in the cytoplasm. The inclusion bodies are the bacterial cellular reserve materials.
They are of two types:
Organic inclusion bodies: They include cyanophycean starch granules and glycogen granules.
Inorganic inclusion bodies: They include polyphosphate granules and sulphur granules.