General Information: Environment: Soil; Isolation: Coal-cleaning residues; Temp: Mesophile; Temp: 30C. This genus comprises about 150 metabolically diverse species of anaerobes that are ubiquitous in virtually all anoxic habitats where organic compounds are present, including soils, aquatic sediments and the intestinal tracts of animals and humans. This shape is attributed to the presence of endospores that develop under conditions unfavorable for vegetative growth and distend single cells terminally or sub-terminally. Spores germinate under conditions favorable for vegetative growth, such as anaerobiosis and presence of organic substrates. It is believed that present day Mollicutes (Eubacteria) have evolved regressively (i.e., by genome reduction) from gram-positive clostridia-like ancestors with a low GC content in DNA. Known opportunistic toxin-producing pathogens in animals and humans. Some species are capable of producing organic solvents (acetone, ethanol, etc,), molecular hydrogen and other useful compounds. Clostridium pasteurianum was first isolated from soil by the Russian microbiologist Sergey Winogradsky. This organism is able to fix nitrogen and oxidize hydrogen into protons. The genes involved in nitrogen fixation and hydrogen oxidation have been extensively studied in this organism.