anaerobiospirillum anaerobiospirillum anaerobiospirillum is a genus of gram-negative anaerobic bacteria recognized as human flora in human gastrointestinal tract, mainly in the human feces. anaerobiospirillum scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: aeromonadales family: succinivibrionaceae genus: anaerobiospirillum species anaerobiospirillum succiniciproducens davis et al. 1976 (approved lists 1980) anaerobiospirillum thomasii malnick 1997