roseospirillum parvum roseospirillum parvum roseospirillum parvum is a phototrophic, nonsulfur, anaerobic and motile bacterium species from the genus of roseospirillum with a bipolar flagella which has been isolated from the sippewissett salt marsh in cape cod in massachusetts in the united states. roseospirillum parvum scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: rhodospirillales family: rhodospirillaceae genus: roseospirillum species: r. parvum binomial name roseospirillum parvumglaeser and overmann 2001 type strain 930i, dsm 12498