acidiphilium cryptum acidiphilium cryptum acidiphilium cryptum is a species of heterotrophic bacteria, the type species of its genus. it is gram-negative, aerobic, mesophilic and rod-shaped. it does not form endospores and some cells are motile by means of one polar flagellum or two lateral flagella lhet2 (=atcc 33463) is the type strain. acidiphilium cryptum scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: rhodospirillales family: acetobacteraceae genus: acidiphilium species: a. cryptum binomial name acidiphilium cryptumharrison 1981