curvibacter gracilis curvibacter gracilis curvibacter gracilis is a gram-negative bacterium from the genus curvibacter and family comamonadaceae, which was isolated from well water. curvibacter gracilis scientific classification domain: bacteria phylum: pseudomonadota class: betaproteobacteria order: burkholderiales family: comamonadaceae genus: curvibacter species: c. gracilis binomial name curvibacter gracilisding and yokota 2004, sp. nov. type strain atcc baa-807, ccug 49445, cip 108608, iam 15033, jcm 21496