cetobacterium somerae cetobacterium somerae cetobacterium somerae is a gram-negative, microaerotolerant, non-spore-forming and rod-shaped bacterium from the genus of cetobacterium which has been isolated from human feces. cetobacterium somerae occur in intestinal tracts of freshwater fish. cetobacterium somerae produces cobalamin. cetobacterium somerae scientific classification domain: bacteria phylum: fusobacteriota class: fusobacteriia order: fusobacteriales family: fusobacteriaceae genus: cetobacterium species: c. somerae binomial name cetobacterium someraefinegold et al. 2003 type strain atcc baa-474, ccug 46254, wal 14325 synonyms cetobacterium someriae