Caractérisation du potentiel PGP de Bacillus rhizosphérique

Abstract

Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria that colonise plant roots and enhance their growth through a wide variety of mechanisms, and their use is constantly increasing in agriculture. In this work, we investigated the production potential of some PGP-related activities of eleven rhizobacteria of the genus Bacillus that were isolated from the fields of different plants, grown in areas in Mostaganem, northwestern Algeria. After isolating the rhizobacteria from the three compartments of the rhizosphere, different identification tests were performed, then all isolates were tested for their ability to fix atmospheric nitrogen, solubilise phosphate and zinc, produce indole acetic acid and produce hydrogen cyanide. The results showed that isolates: LAX11, LAX12, PBX4, PAY2, PAY8, PAZ10, PAZ11, PAX13 and PDY7 induced the production of indole acetic acid (IAA) with levels ranging from 4.58h ± 0.33 μg/ml up to 25.16a±0.73μg/ml, all isolates were nitrogen fixers while none of the isolates were able to produce HCN. Most isolates formed a transparent halo around the colonies, signifying zinc solubilisation with ES values ranging from 207.12c±6.56 to 250a±11 and phosphate solubilisation on pikvoskaya agar medium with ES values ranging from 209.33c±9.02 to 550a±12. The results obtained point to the possibility of using Bacillus rhizobacteria as an organic fertiliser for better yields.