THERMOPHILIC AND HYPERTHERMOPHILIC MICROORGANISMS IN 3-30-DEGREES-C HYDROTHERMAL FLUIDS FOLLOWING A DEEP-SEA VOLCANIC-ERUPTION

Thermophilic and hyperthermophilic microorganisms were cultured from 1 8 degrees C diffuse hydrothermal fluids at the CoAxial nt deep-sea hyd rothermal vent site 3 months after an eruption resulting from an intru sion of magma into shallow crust. The abundances of these organisms de creased over a 3-year period as the shallow magma cooled. The presence of these organisms at the site suggests that these organisms grew in response to nutrient input from hydrothermal fluid circulation and the n were flushed to the surface following the eruption. Thermophiles and hyperthermophiles were also found in low-temperature (3-30 degrees C) fluids at three other chronic, highly active deep-sea vent sites. The origin of these organisms is not known but may include the overlying seawater or a shallow to deep subseafloor habitat. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V.