Thermoplasmatales

The thermal plasma valley are the only order of the class of Thermoplasmata within the Archaea. They comprise three families with four genera of thermophilic and extremely acidophilic, ie heat-and acid -loving microorganisms. Your growth optima are from 40 to 60 ° C and a pH of 0.5 to 2 are the only known organisms that can survive and grow at a pH value of less than 0. The pH value is kept constant at about 7 inside the cell. Thermal plasma Tales are spherical, only 0.5 to 2 microns wide Archaea without a cell wall. Some species have flagella. They probably feed on the organic remains of other organisms that are killed by the extreme environmental conditions of their habitat.

• 2.1 Notes and references

System

The order consists of four genera in three families:

• Family Ferroplasmaceae Golyshina et al. 2000 Genus Ferroplasma Golyshina et al. 2000

• Genus Picrophilus Schleper et al. 1996

• Genus Thermoplasma Darland et al. 1970

• Genus Thermogymnomonas Itoh et al. 2007

Thermal plasma

Thermoplasma acidophilum and T. volcanium grow optimally at a temperature of 55 to 60 ° C and a pH of about 2 to anaerobic sulfur respiring or even grow aerobically. Described for the first time they were of T.D. Brock 1970. Due to the lack of cell wall is arranged them at that time the mycoplasma to. They can be found for example on spontaneously combustible coal slag heaps, as they can utilize the resulting there by burning coal residues. T. volcanium can also be found on volcanic acidic soil. The cell membrane consists of Lipoglycan. The basic structure of this molecule consists of Tetraetherlipidmonoschichten. Sugar molecules such as glucose and mannose are combined with the ether lipids. Are also incorporated into the membrane glycoproteins, which leads to a greater stability at high temperatures. The genome is relatively small with 1.56 Mbp. 1509 open reading frames could be located thereon. The DNA is packaged by means of basic proteins into spherical structures.

Ferroplasma

Ferroplasma is not thermophilic, so grows at lower temperatures around 35 ° C. Ferroplasma has the ability to oxidize iron ( Fe2 to Fe3 ). Since in this reaction acid is formed, this acidophilic organism itself creates an optimal environment. Iron is not only the production of energy, it also plays a role in anabolism. Thus it was found that more than 80 percent of the proteins contain acidiphilum of Ferroplasma iron atoms. One can find Ferroplasma especially in acid mine water.

Picrophilus

Picrophilus has a cell wall composed of protein. Unlike Ferroplasma and Thermoplasma be GC content is low. Picrophilus is probably the säuretoleranteste organism in the world. Its growth is pH 0.7. However, it can also grow up to pH 0.06. Cause of this extreme Acidophilie is probably the lipid arrangement of the cell membrane. In the extremely acidic environment of the lipids are close to each other. At higher pH ( from pH 4 ) However, there are gaps between the lipids, which eventually leads to the degradation of the membrane.