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During a screening for the diversity of actinobacterial strains from Saharan soil samples collected from Béchar region (Algeria), one strain designated KB-T3 was isolated by dilution technique on chitin-vitamins agar medium. The taxonomic position of this strain was determined by using a polyphasic approach. Morphological and chemical characteristics of the KB-T3 strain were consistent with those of the genus Thermobifida. The KB-T3 strain had a white aerial mycelium with dictomically branched sporophores carrying coccoid secluded spores. The substrate mycelium was pale yellow, sterile, and non-fragmented. The strain is characterized by the presence of meso-diaminopimelic acid in the cell wall, the galactose in whole-cell, and phosphatidylethanolamine in the cell membrane. The unique characteristic of this strain was its abundant growth with the absence of NaCl and in temperature‎ ranging from 40 to 65 °C, its capacity to decompose acetate, and its ability to use fructose, glucose and xylose as sole carbon source. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the strain KB-T3 should be classified in the genus Thermobifida and exhibited 99.79 % gene sequence similarity to Thermobifida fusca NBRC 14071T.

Background and Objectives: Hadjr El Melh of Djelfa is an example of hypersaline ecosystems, which can harbor a wide variety of microorganisms under hostile physicochemical conditions. Given the importance of the study of halophilic mi- croorganisms present there in terms of fundamental and applied microbiology, the purpose of this study was to characterize some halophilic archaea isolated from the brines of this environment. Materials and Methods: Eight water samples were chosen randomly and collected for physicochemical and microbiolog- ical analyses. Isolation of halophilic archaea was carried out by membrane filter technique. Ten strains were identified by polyphasic approach and tested for enzymes production. Results: Water samples of Djelfa’s rock salt were slightly acidic to neutral in pH (6.55-7.36) with salinity ranging from 258.68 g/l to 493.91 g/l. Phenotypic, biochemical, taxonomic and phylogenetic characteristics indicated that all strains were classified within the family of Halobacteiaceae. Based on the comparison of DNA sequences encoded 16S rRNA, it was determined that seven strains were affiliated to the genus Haloarcula, two strains were related to the genus Halobacterium and one strain within the genus Haloferax. Production of different enzymes such as protease, amylase, esterase, lipase, leci- thinase, gelatinase and cellulase on solid medium indicated that one strain (S2-2) produced amylase, esterase, lecithinase and protease. However, no strains showed cellulolytic or lipolytic activity. Gelatinase was found in all tested strains. Conclusion: This report constitutes the first preliminary study of culturable halophilic archaea recovered from the brines of Djelfa’s rock salt with a promising enzymatic potential in various fields of biotechnology.