thermoplasmatales thermoplasmatales in taxonomy, the thermoplasmatales are an order of the thermoplasmata. all are acidophiles, growing optimally at ph below 2. picrophilus is currently the most acidophilic of all known organisms, being capable of growing at a ph of -0.06. many of these organisms do not contain a cell wall, although this is not true in the case of picrophilus. most members of the thermotoplasmata are thermophilic. thermoplasmatales cuniculiplasma divulgatum scientific classification domain: archaea kingdom: euryarchaeota phylum: euryarchaeota class: thermoplasmata order: thermoplasmatalesreysenbach 2002 families thermogymnomonas cuniculiplasmataceae ferroplasmataceae picrophilaceae thermoplasmataceae synonyms picrophilales cavalier-smith 2002 phylogeny the currently accepted taxonomy is based on the list of prokaryotic names with standing in nomenclature (lpsn) and national center for biotechnology information (ncbi). 16s rrna-based ltp_01_2022 53 marker proteins based gtdb 07-rs207 thermoplasmatales thermoplasmataceae thermogymnomonas cuniculiplasmataceae picrophilaceae ferroplasmataceae thermoplasmataceae thermoplasma cuniculiplasma thermogymnomonas picrophilus acidiplasma ferroplasma