Aquicella is a genus of Gram-negative rod-shaped cells and filaments in the family Coxiellaceae from the order Legionellales.

All members are strictly aerobic, non-motile, do not produce spores and are oxidase and catalase negative.

Aquicella species can grow in temperatures ranging from 30 °C to 43 °C and require a neutral pH and growth media containing activated charcoal and a-ketoglutarate.

Analyses of genome sequences from Aquicella species identified six conserved signature indels (CSIs) as exclusively present in members of this genus in the proteins 30S ribosomal protein S6-L-glutamate ligase, crossover junction endodeoxyribonuclease RuvC, Tim44 domain-containing protein, pyruvate dehydrogenase (acetyl-transferring), homodimeric type, c-type cytochrome and response regulator transcription factor.

[2] These CSIs serve to molecularly demarcate this genus from other Coxiellaceae species and all other bacteria.