BIODIVERSITY OF HYPERTHERMOPHILIC ARCHAEA FROM HYDROTHERMAL VENTS OF THE EAST PACIFIC RISE

During the MVT'90 US oceanographic cruise, various samples (pieces of hydrothermal chimneys, Pompei worms tubes) were collected from deep-se a hydrothermal vents of the East Pacific Rise. They led to the isolati on of 125 thermophilic, heterotrophic, sulfur-reducing and anaerobic s trains. The results indicated an acidophilic behaviour of the most the rmophilic strains (97 degrees C). Taxonamic study of the 38 most therm ophilic isolates revealed 2 sub-groups depending on isolation temperat ures and G + C% contents of genoms. DNR/DNA hybridization data with pr eviously described Archaea of the genera Thermococcus, Pyrococcus and Staphylothermus showed an important biodiversity.