THERMOSTABLE AMYLOLYTIC ENZYMES OF THERMOPHILIC MICROORGANISMS FROM DEEP-SEA HYDROTHERMAL VENTS

Microorganisms growing above 60 degrees C isolated from deep-sea hydro thermal vents were screened for amylolytic activity. Of the 269 strain s tested, 70 were found to be positive. Nine archaea (including Thermo coccus hydrothermalis AL662 and Thermococcus fumicolans ST557) and one thermophilic bacterium were selected for the determination of thermos tability, and the temperature and pH optima of their amylolytic enzyme s. Pullulanase, alpha-glucosidase and alpha-amylase activities were de tected in four archaeal strains (including AL662 and ST557) related to the genus Thermococcus. The anaerobic hyperthermophilic archaeon, The rmococcus hydrothermalis was chosen for the further study of the alpha -glucosidase activity, and a preliminary characterization of this enzy me was carried out. The small number of highly thermostable alpha-gluc osidases that has been described to date, combined with the very inter esting properties of this enzyme, suggest a use for this enzyme in bio technological processer.