geovibrio geovibrio geovibrio is a gram-negative, non-spore-forming, strictly anaerobic and motile genus of bacteria from the family of deferribacteraceae. geovibrio scientific classification domain: bacteria phylum: deferribacterota class: deferribacteres order: deferribacterales family: deferribacteraceae genus: geovibriocaccavo et al. 2000 type species geovibrio ferrireducens species g. ferrireducens g. thiophilus