porphyromonadaceae porphyromonadaceae porphyromonadaceae is a family of gram-negative bacteria described by noel r. krieg in 2015. it contains nine genera, five of which are validly published by the international code of nomenclature of prokaryotes. bacteria with 16s ribosomal rna highly similar to the porphyromonas genus, as compared to the larger taxonomic order bacteroidales, are classified in this family. porphyromonadaceae colonies of porphyromonas gulae growing on a tsa plate scientific classification domain: bacteria phylum: bacteroidota class: bacteroidia order: bacteroidales family: porphyromonadaceaekrieg 2012 genera "culturomica" ndongo et al. 2016 falsiporphyromonas wagener et al. 2014 "gabonia" mourembou et al. 2016 "ihubacter" ndongo et al. 2016 "lascolabacillus" beye et al. 2016 macellibacteroides jabari et al. 2012 microbacter sánchez-andrea et al. 2014 porphyromonas shah and collins 1988 "sanguibacteroides" sydenham et al. 2015 bacteria of the porphyromonadaceae family have coccobacilli shapes, are obligately anaerobic, non-spore forming, and non-motile. many of its species are members of animal gastrointestinal and oral microbiomes, such as porphyromonas gingivalis, which causes periodontal disease.