What is "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 growing at a minimum 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 of members of the Thermotoplasmata are thermophilic.