[Demonstration of thermostable enzymes in thermophilic micro-organisms of hydrothermal origin]

During 3 cruises in the Pacific ocean, hydrothermal samples have been collected and some thermophilic bacteria and archaea have been purified. Four enzymatic activities have been screened on 77 chemo-organoheterotrophic thermophilic microorganisms. Forty-two isolates exhibited intracellular beta-glucosidase activity whereas only 7 (including only one archaeon) showed alcohol dehydrogenase one. Protease activity was not detected on only 6 isolates over 77. Twenty-seven isolates exhibited esterase activity and 3 different electrophoretic patterns have been revealed. No isolate was found to exhibit the 4 activities. Preliminary characterization of these activities showed high thermophily and thermostability, properties which could be used in potential biotechnological applications.