Polyextremotolerant Bacillus cereus groups isolated from Algerian arid ecosystems and bioprospecting for their bioactive compounds.

In previous work, 70 Bacillus sp. isolates originating from 4 soil plots from southwestern Algeria were studied for their poten al plant growth promoting (PGP). In this study, pH, organic ma er, texture, Calcium carbonate, and Electrical conduc vity of the soil samples were determined, 08 selected isolates were idenfied based on rRNA 16S and FAME analysis using GC. Antimicrobial activity against bacteria and fungi were also investigated. All the four soils were moderately Calcium carbonate, pH of soil was alkaline. Our results showed that the electrical conductivity was high for all soils and the four soil isolates in semi-arid and arid regions were poor in organic matter. In addition, Fatty acid analysis showed the presence of 17 di erent fa y acids. Three fa y acids, 15:0 iso, 16:0, and 17:0, 17:0 were present in all isolates. Thus, the isolates were classified into two clusters which were con rmed the results of 16SrRNA sequence analysis. Preliminary screening revealed that the Bacillus thuringiensis isolates showed strong an bacterial and an fungal proper es against S. aureus (between 7mm to 11mm) and A. niger (between 7mm to 8mm). The aim of the present study is the screening of eight Bacillus cereus strains isolated from four rhizosphere soil sample of South-Western region of Algeria province for their an microbial activity.