Screening d’activités hydrolytiques extracellulaires chez des souches bactériennes aérobies thermophiles isolées à partir de sources thermales terrestres de l’Est Algérien.

Abstract

Thermophilic and hyperthermophilic microorganisms inhabiting hot environments such as terrestrial hot springs have interesting molecular adaptation capacities and constitute an important source of bioactive molecules emerging from unique molecular and biochemical mechanisms. Hydrolytic enzymes of these organisms offer major advantages and give new possibilities to ameliorate existing processes or to create new ones. With the purpose of studying some of their enzymatic potentials, 83 thermophilic, aerobic bacteria strains were isolated from water and sediment samples taken from different points divided between the regions of Guelma and Ouargla located in North-Eastern and SouthEastern of Algeria, respectively. Phenotypic characterization has been realized, and allowed to obtain some morphological, biochemical and physiological proprieties of these microorganisms, these data led to realize a dendrogram by numerical taxonomy. Four types of hydrolytic activities were investigated by using seven different substrates. Strains were generally rods and filaments, Gram positive in most cases; they were moderately thermophiles, aerobes and neutrophiles. Numerical analyses clustred them into 3 principal phenons, based on similarity between strains. Screening for hydrolytic activities led to find one or several types of hydrolases in seventy-seven strains, proteolytic and amylolytic activities were mostly found.