thiotrichaceae thiotrichaceae the thiotrichaceae are a family of pseudomonadota, including thiomargarita namibiensis, the largest known bacterium. some species are movable by gliding, thiospira by using flagella. thiotrichaceae scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: thiotrichales family: thiotrichaceaegarrity et al. 2005 genera achromatium beggiatoa leucothrix thiobacterium "candidatus thiolava" thiomargarita thioploca thiospira thiothrix