Isolement et caractérisation des rhizobactéries solubilisant le Zinc

Abstract

The ability of bacteria to solubilize zinc is a crucial trait for plant nutrition, playing an essential role in providing this micronutrient. This study aims to isolate bacteria capable of solubilizing zinc and to identify their characteristics involved in promoting plant growth. 37 bacterial isolates were obtained from the rhizosphere of various plants (broad bean, strawberry, onion, beet, pea) in the Mostaganem region. Among them, 25 isolates demonstrated the ability to solubilize zinc on a modified Bunt and Rovira medium with zinc oxide as the sole zinc source. The selection of these isolates was based on the formation of clear halo zones and colony diameter, with the maximum zinc solubilization observed in isolate Wz2 with a concentration of 632 ± 252 μg/ml. The isolates were then evaluated for plant growth-promoting activities such as phosphate solubilization and the production of indole acetic acid (IAA) and hydrogen cyanide (HCN). The results show that the majority of isolates possess phosphate solubilization capacities with concentrations ranging from 79.17 ± 1.002 to 32.3 ± 0.9 μg/ml and IAA production with concentrations from 24.33 ± 0.037 to 2.63 ± 0.048 μg/ml.