[A new species of Thermoplasma].

An extremely thermoacidophilic strain, ES-23, was isolated from a self-heating coal spoil pile, Sichuan, China. The new isolate grows between 50 and 75 degrees C with optimum 70 degrees C and pH 1.0-5.0 with optimum 2.0. Strain ES-23 is aerobic and facultative autotrophic depending both heterotrophically on organic compounds and autotrophically on elemental sulfur as energy source and CO2 as carbon source. G-, spherical or oval with 0.9-1.5 microns in diameter. The autotrophic growth showed peri pilus-like structure. Cells Lack a rigid cell wall and surrounded only by a single triple layed membrane containing ether lipids. GC content of DNA is 38 mol%(Tm). It has been determined as a new species of Thermoplasma genus and named Thermoplasma thiooxidans sp. nov.