Synergistota
The Synergistota is a phylum of anaerobic bacteria that show Gram-negative staining and have rod/vibrioid cell shape. Although Synergistota have a diderm cell envelope, the genes for various proteins involved in lipopolysaccharides biosynthesis have not yet been detected in Synergistota, indicating that they may have an atypical outer cell envelope. The Synergistota inhabit a majority of anaerobic environments including animal gastrointestinal tracts, soil, oil wells, and wastewater treatment plants and they are also present in sites of human diseases such as cysts, abscesses, and areas of periodontal disease. Due to their presence at illness related sites, the  Synergistota are suggested to be opportunistic pathogens but they can also be found in healthy individuals in the microbiome of the umbilicus and in normal vaginal flora. Species within this phylum have also been implicated in periodontal disease, gastrointestinal infections and soft tissue infections. Other species from this phylum have been identified as significant contributors in the degradation of sludge for production of biogas in anaerobic digesters and are potential candidates for use in renewable energy production through their production of hydrogen gas. All of the known Synergistota species and genera are presently part of a single class (Synergistia), order  (Synergistiales), and family (Synergistaceae). Comparative genomics and molecular signatures. Recent comparative analyses of sequenced Synergistota genomes have led to identification of large numbers of conserved signature indels (CSIs) in protein sequences that are specific for either all sequenced Synergistota species or some of their sub-clades that are observed in phylogenetic trees. Of the CSIs that were identified, 32 in widely distributed proteins such as RpoB, RpoC, UvrD, GyrA, PolA, PolC, MraW, NadD, PyrE, RpsA, RpsH, FtsA, RadA, etc., including a large >300 aa insert in the RpoC protein, are present in various Synergistota species, but except for isolated  bacteria, these CSIs are not found in the protein homologues from all other organisms. These CSIs provide novel molecular markers for distinguishing Synergistota species from all other bacteria. Seven other CSIs in important proteins including a 13 aa in RpoB were found to be uniquely present in "Jonquetella", "Pyramidobacter" and "Dethiosulfovibrio" species indicating a close and specific relationship among these bacteria, which is also strongly supported by phylogenetic trees. Fifteen addition CSIs that were only present in "Jonquetella" and "Pyramidobacter" indicate a close association between these two species. Lastly, a close relationship between the "Aminomonas" and "Thermanaerovibrio" species is also  supported by 9 identified CSIs. The identified molecular markers provide reliable means for the division of species from the phylum Synergistota into intermediate taxonomic ranks such as families and orders. Phylogeny. The phylogeny based on the work of the All-Species Living Tree Project. Taxonomy. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LSPN) and the National Center for Biotechnology Information (NCBI). Notes: ♠ Strain found at the National Center for Biotechnology Information (NCBI) but not listed in the List of Prokaryotic names with Standing in Nomenclature (LPSN)