Contribution à l'étude des Bacillales halophiles d'un échantillon de Hammam Zelfana (Ghardaia)

Abstract

The study of extremophilic bacterial species opens up gates of research to understanding the mechanisms of adaptation and developmental growth under unfavorable conditions. Depending on the extreme conditions, the microorganisms can be: thermophiles, halophiles, psychrophiles, acidophiles, alkaliphiles or piezophiles. The main objective assigned to this work is to isolate extremophilic spore-forming bacteria from soil samples from the region of Zelfana. After heat treatment in a water bath for 20 minutes at 100 ° C to eliminate the vegetative forms, the isolation of the strains was carried out from a nutrient agar medium in the presence of 15% NaCl for 20 days of incubation. After the morphological identification of a selected strain (F1) which is capable of forming endospores, and Gram positive, and has a rod shape. Physiological identification of the isolate shows that it is tolerant to the following NaCl concentrations: [0, 0, 5.1, 1, 5.2, 2.5% (w / v)]. The results of this study show that the isolated strain belonging to the order of Bacillales.