Deinococcota (synonym, Deinococcus-Thermus) is a phylum of bacteria with a single class, Deinococci, that are highly resistant to environmental hazards, also known as extremophiles.

[5][6][7] The phylum Deinococcota consists of a single class (Deinococci) and two orders: Though these two groups evolved from a common ancestor, the two mechanisms of resistance appear to be largely independent.

[4][11] These CSIs and CSPs are distinguishing characteristics that delineate the unique phylum from all other bacterial organisms, and their exclusive distribution is parallel with the observed differences in physiology.

Some of the CSIs found to support order level distinctions are thought to play a role in the respective extremophilic characteristics.

[17] Two CSPs that were found uniquely for all members belonging to the Deinococcus genus are well characterized and are thought to play a role in their characteristic radioresistant phenotype.