thiohalocapsa thiohalocapsa thiohalocapsa is a gram-negative and non-motile genus of bacteria from the family of chromatiaceae. thiohalocapsa scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: chromatiales family: chromatiaceae genus: thiohalocapsaimhoff et al. 1998 type species thiohalocapsa halophila species t. halophila t. marina