EXTREMELY HALOPHILIC ARCHAEA FROM ALGERIAN SALT LAKES: ISOLATION, PHYLOGENETIC IDENTIFICATION AND BIOPROSPECTION OF HYDROLYTIC ENZYMES

Hyper-saline aquatic ecosystems are among the most inhospitable habitats where life can be found; Chotts and sebkhas constitute a model of extreme environments where lives a halophilic microflora adapted to these conditions. These habitats are not sufficiently studied in Algeria and this research has been carried out on four distant and different sebkhas where the salt reaches more than 300 g/L. The physical-chemical analysis showed that these waters contain numerous minerals, of which the chlorides are the most dominants. The study of the microflora revealed the presence of an important morphologic, physiologic, metabolic and phylogenetic diversity, including archaeal species. Twelve strictly halophilic archaea (XA1, XC1, XC2, XE1, XE2, WA1, WC1, YA1, YA2, YF2, ZC1 and ZD1) were selected for further characterization. The growth occurred between 15 and 30% (w/v) NaCl with an optimum at 20% (w/v) NaCl. 16S rRNA gene sequencing revealed that the strains belonged to Halorubrum sp, Natribaculum sp, Haloarcula sp, Natrinema sp, Halostagnicola sp, Haloferax sp and Haloterrigena sp genera. Noting that these halophilic Archeae are capable of producing different enzymes at high salt concentrations (20% NaCl). The production yields obtained are very promising for applications in the biotechnology and industrial microbiology.